JP7736098B2 - Resin composition and syringe filled with resin composition - Google Patents

Description

The present invention relates to a resin composition, a syringe filled with the resin composition, etc.

In recent years, demand for small, highly functional electronic devices such as smartphones and tablet devices has been increasing. These small electronic devices typically use encapsulating materials for semiconductor chip packages. Known encapsulating materials are formed by curing resin compositions (Patent Documents 1 to 3).

Known methods for molding encapsulating materials include melt casting, transfer molding, injection molding, and compression molding. In compression molding, for example, a resin composition is dispensed onto a substrate using a syringe, the mold is clamped, and pressure and, if necessary, heat are applied to the resin composition to perform compression molding. When dispensing a resin composition using a syringe, good dispensing and ejection workability are required to improve workability. Furthermore, good resin flow properties are required to prevent resin leakage from the mold during compression molding. However, at present, these issues cannot be fully resolved simply by adjusting the thixotropy and viscosity of the resin composition.

Note that a syringe filled with a resin composition containing voids that can prevent air from entering, which can cause intermittent discharge, has been known (Patent Document 4).

Japanese Patent Application Laid-Open No. 2004-137370 JP 2012-188555 A JP 2016-74920 A Japanese Patent Application Laid-Open No. 2020-127919

The objective of the present invention is to provide a resin composition and a syringe filled with the resin composition that exhibits excellent dispensability, ejection workability, and resin flow properties.

In order to achieve the objectives of the present invention, the inventors conducted extensive research and discovered that, after dispensing a resin composition onto the surface of a silicon wafer to form a resin dome of the resin composition, if the change in the shape of the resin dome over time satisfies certain conditions, the dispensing properties, discharge operability, and resin flow properties are surprisingly good, leading to the completion of the present invention.

That is, the present invention includes the following.
[1] A resin composition-filled syringe comprising a syringe and a resin composition filled in the syringe,
The resin composition
In a resin composition evaluation test in which a resin composition is dispensed onto the surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and changes in the shape of the resin dome are measured,
The height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing is defined as H ₁ ,
When the height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing is _H2 ,
A syringe filled with a resin composition, which satisfies the condition of the following formula (1):
0.15<H ₂ /H ₁ <0.90 (1)
[2] The evaluation test
The syringe filled with the resin composition according to the above-mentioned [1], comprising dispensing 40 g±1.5 g of the resin composition at 23°C onto the surface of the silicon wafer at a rate of 2 g/sec under a condition of 23°C from a discharge outlet installed at a position 5 cm high from the surface of the silicon wafer, and stopping the dispensing to form a resin dome of the resin composition.
[3] In the evaluation test,
If the discharge port and the resin dome are not in contact with each other when the dispensing of the resin composition is stopped, the time when 40 g±1.5 g of the resin composition has been dispensed is regarded as the dispensing completion time.
The syringe filled with a resin composition according to the above [2], wherein if the outlet and the resin dome are in contact when the dispensing of the resin composition is stopped, the outlet is pulled up after the dispensing is stopped to separate the outlet from the resin dome, and the point at which the outlet separates from the resin dome is regarded as the point at which the dispensing is completed.
[4] The diameter of the contact surface of the resin dome with the silicon wafer 60 seconds after the completion of dispensing is L ₁ ,
The syringe filled with the resin composition according to any one of the above [1] to [3], further satisfying the condition of the following formula (2), where _L2 is the diameter of the contact surface of the resin dome with the silicon wafer 180 seconds after the completion of dispensing.
0.40<L ₁ /L ₂ <0.96 (2)
[5] The syringe filled with the resin composition according to any one of the above [1] to [4], wherein the viscosity of the resin composition at 25°C is 100 Pa·s or more and 500 Pa·s or less.
[6] The syringe filled with the resin composition according to any one of the above [1] to [5], wherein the resin composition contains (A) a thermosetting resin.
[7] The syringe filled with the resin composition according to any one of the above [1] to [6], wherein the resin composition contains (B) an inorganic filler.
[8] The syringe filled with the resin composition according to any one of the above [1] to [7], wherein the resin composition contains (C) a silane coupling agent.
[9] In a resin composition evaluation test in which a resin composition is dispensed onto a surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and a change in the shape of the resin dome is measured,
The height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing is defined as H ₁ ,
When the height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing is _H2 ,
A resin composition that satisfies the condition of the following formula (1):
0.15<H ₂ /H ₁ <0.90 (1)
[10] The evaluation test
The resin composition according to the above-mentioned [9], comprising dispensing 40 g±1.5 g of the resin composition at 23°C onto the surface of the silicon wafer at a rate of 2 g/sec under a condition of 23°C from a discharge port installed at a position 5 cm high from the surface of the silicon wafer, and stopping the dispensing to form a resin dome of the resin composition.
[11] In the evaluation test,
If the discharge port and the resin dome are not in contact with each other when the dispensing of the resin composition is stopped, the time when 40 g±1.5 g of the resin composition has been dispensed is regarded as the dispensing completion time.
[11] The resin composition according to the above [10], wherein, if the discharge outlet and the resin dome are in contact when dispensing of the resin composition is stopped, the discharge outlet is pulled up after dispensing is stopped to separate the discharge outlet from the resin dome, and the time when the discharge outlet separates from the resin dome is regarded as the time when dispensing is completed.
[12] The diameter of the contact surface of the resin dome with the silicon wafer 60 seconds after the completion of dispensing is L ₁ ,
When the diameter of the contact surface of the resin dome with the silicon wafer 180 seconds after the completion of dispensing is _L2 ,
The resin composition according to any one of [9] to [11] above, further satisfying the condition of the following formula (2):
0.40<L ₁ /L ₂ <0.96 (2)
[13] The resin composition according to any one of [9] to [12] above, wherein the viscosity of the resin composition at 25°C is 100 Pa·s or more and 500 Pa·s or less.
[14] The resin composition according to any one of [9] to [13] above, comprising (A) a thermosetting resin.
[15] The resin composition according to any one of [9] to [14] above, which contains (B) an inorganic filler.
[16] The resin composition according to any one of the above [9] to [15], further comprising (C) a silane coupling agent.
[17] The resin composition according to any one of [9] to [16] above, for forming an insulating layer of a semiconductor chip package.
[18] The resin composition according to any one of the above [9] to [16] for forming an insulating layer of a circuit board.
[19] The resin composition according to any one of [9] to [16] above, for encapsulating a semiconductor chip in a semiconductor chip package.
[20] A cured product of the resin composition according to any one of [9] to [19] above.
[21] A circuit board comprising an insulating layer formed from a cured product of the resin composition according to any one of [9] to [19] above.
[22] A semiconductor chip package including the circuit board according to [21] above and a semiconductor chip mounted on the circuit board.
[23] A semiconductor chip package comprising a semiconductor chip and a cured product of the resin composition according to any one of [9] to [19] above, which encapsulates the semiconductor chip.
[24] A semiconductor device comprising the semiconductor chip package according to [22] or [23] above.
[25] A method for evaluating a resin composition, comprising dispensing a resin composition on a surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and measuring a change in the shape of the resin dome,
The height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing is defined as H ₁ ,
When the height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing is _H2 ,
A method for evaluating a resin composition, comprising determining whether or not the condition of the following formula (1) is satisfied:
0.15<H ₂ /H ₁ <0.90 (1)

The resin composition of the present invention can provide a resin composition and a syringe filled with the resin composition that exhibit excellent dispensability, ejection workability, and resin flow properties.

FIG. 1 is a cross-sectional view that schematically illustrates an example of a syringe filled with a resin composition according to one embodiment of the present invention. FIG. 2 is a side view schematically showing an example of a nozzle to be attached to a syringe filled with a resin composition according to one embodiment of the present invention. FIG. 3 is a horizontal cross-sectional view schematically showing a resin dome formed on a silicon wafer at the completion of dispensing in an evaluation test of one embodiment, together with a part of a syringe filled with the resin composition. FIG. 4 is a vertical plan view schematically showing a resin dome formed on a silicon wafer at the completion of dispensing in an evaluation test of one embodiment.

The present invention will now be described in detail with reference to preferred embodiments. However, the present invention is not limited to the following embodiments and examples, and can be modified and implemented as desired without departing from the scope of the claims of the present invention and their equivalents.

<Syringe filled with resin composition>
The syringe filled with a resin composition of the present invention includes a syringe and a resin composition filled in the syringe.

The configuration of a syringe filled with a resin composition according to the present invention and a nozzle attached thereto will be described using an example. Figure 1 is a cross-sectional view that schematically shows an example of a syringe filled with a resin composition according to one embodiment of the present invention. Figure 2 is a side view that schematically shows an example of a nozzle that can be attached to a syringe filled with a resin composition according to one embodiment of the present invention.

As shown in FIG. 1, a syringe 10 filled with a resin composition includes a syringe 11 and a resin composition 12 filled in the syringe 11. The syringe 11 includes a plunger 13 for pushing out the resin composition 12. The syringe 10 also includes a female thread 14 on the inner surface of one end of the reduced diameter side of the syringe 11, with threads for attaching a nozzle 20. The syringe 10 has a discharge port 15 at the tip of the one end for discharging the resin composition, and an opening 16 at the other end opposite the discharge port 15 through which a plunger rod is inserted. The discharge port 15 has a tip cap 17 that closes the discharge port 15 and is removed before use, and the opening 16 has an end cap 18 that closes the opening 16 and is removed before use.

In one embodiment, the syringe 11 may be any syringe that can be used to dispense a sealing material that can be filled with the resin composition of the present invention. It is particularly preferable to use a "12 oz syringe" that meets the product standard. An example of a commercially available "12 oz syringe" is the "5194C" manufactured by Sanei Tech Co., Ltd. The "12 oz syringe" may have an inner diameter of the outlet 15 of 14.22 mm, an outer diameter of 19.30 mm, an inner diameter of the opening 16 of 40.26 mm, and a length of 311.40 mm from the outlet 15 to the opening 16 of the syringe 11.

The resin composition-filled syringe 10 may be used with a nozzle 20 attached. When attaching the nozzle 20 to the resin composition-filled syringe 10, the tip cap 17 is removed. As shown in FIG. 2 , the nozzle 20 comprises a tube portion 21 and a syringe connecting portion 22, with a portion of the tube portion 21 inserted and secured in place in the syringe connecting portion 22. The tip of the tube portion 21 has a nozzle discharge portion 23 for discharging the resin composition, and the other end of the syringe connecting portion 22 has a nozzle opening 24 for delivering the resin composition 12 from the syringe 11 when the nozzle 20 is secured to the resin composition-filled syringe 10, resulting in a tubular shape as a whole. The outer surface of the other end of the syringe connecting portion 22 has a male thread 25 that meshes with the female thread 14 for securing the nozzle 20 to the resin composition-filled syringe 10. The tube portion 21 is made of a soft material and is designed so that it can be pushed by external pressure to block the resin composition and stop dispensing.

<Resin composition and evaluation test thereof (evaluation method)>
The resin composition used in the present invention satisfies the condition of formula (1) (preferably also the condition of formula (2)) described below in the results of evaluation tests of the resin composition described below.

The evaluation tests (evaluation methods) for the resin compositions are described below.

In the evaluation test for evaluating the resin composition, the resin composition is dispensed onto the surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and the change in shape of the resin dome is measured to determine whether the condition of formula (1) (preferably also the condition of formula (2)) described below is satisfied.

A syringe may be used in the evaluation test, and the resin composition may be dispensed from the syringe outlet. The syringe used in the evaluation test may be, for example, a syringe 10 filled with the resin composition, as shown in Figure 1. When dispensing, the tip cap 17 and end cap 18 of the syringe are removed. Furthermore, when dispensing to measure the specific conditions related to the shape of the resin dome, as described below, the nozzle 20 may or may not be attached. In the evaluation test, a regular dispenser is used for dispensing. An example of a commercially available dispenser used in the evaluation test is the "Liquid Manual Dispenser" manufactured by Apic Yamada Co., Ltd.

The silicon wafers used in the evaluation tests can have an arithmetic mean roughness (Ra) of 10 Å or less, and there are no particular restrictions on the size as long as the evaluation tests can be performed.

The formation of a resin dome by dispensing in an evaluation test of one embodiment will be described using schematic diagrams. Figure 3 is a horizontal cross-sectional view showing a resin dome formed on a silicon wafer at the completion of dispensing in an evaluation test of one embodiment, along with a portion of a syringe filled with the resin composition. Figure 4 is a vertical plan view showing a resin dome formed on a silicon wafer at the completion of dispensing in an evaluation test of one embodiment.

In this embodiment, a syringe without a nozzle attached is used in the evaluation test. In this embodiment, a case where the nozzle 20 is not attached will be described as in Test Example 3 below. As shown in Figure 3, first, the syringe 10 filled with the resin composition, from which the tip cap 17 and end cap 18 have been removed, is placed so that the height _Hs from the surface of the horizontally placed silicon wafer 40 to the discharge port 15 is 5 cm.

Next, in this embodiment, 40 g±1.5 g of resin composition at 23°C, the same temperature as the ambient air, is dispensed onto the silicon wafer surface from the discharge port 15 of the resin composition-filled syringe 10 at a rate of 2 g/second under 23°C conditions. Dispensing is stopped when 40 g±1.5 g has been dispensed, forming a resin dome 20 of the resin composition. "Stopping dispensing" means cutting off the supply of resin composition onto the silicon wafer surface by stopping the plunger, blocking the discharge port (nozzle discharge port), or, when a nozzle is used, blocking the nozzle tube. In this embodiment, dispensing is stopped when 40 g±1.5 g of resin composition has been dispensed, so the amount of resin composition in the resin dome 20 is 40 g±1.5 g.

Furthermore, in this embodiment, if the discharge port and the resin dome are in contact when dispensing of the resin composition is stopped, the discharge port is pulled up after dispensing is stopped to separate the discharge port from the resin dome.

Furthermore, in this embodiment, if the discharge port and the resin dome are not in contact when the dispensing of the resin composition is stopped, the point at which 40 g ± 1.5 g of resin composition has been dispensed is regarded as the point at which dispensing is complete.If the discharge port and the resin dome are in contact when the dispensing of the resin composition is stopped, the discharge port is pulled up after dispensing is stopped, and the point at which the discharge port separates from the resin dome is regarded as the point at which dispensing is complete.

The resin dome 30 of the resin composition is a dome-shaped mass of liquid resin composition, as shown in Figure 3. Since the resin composition typically spreads in a circular shape from the point where it falls, the contact surface with the silicon wafer 40 can be circular, as shown in Figure 4.

After dispensing, the resin dome 30 of the resin composition usually expands circularly over time, centered on the point where the resin composition fell. Therefore, the height _H0 from the contact surface of the resin dome 30 with the silicon wafer 40 to the apex of the resin dome decreases over time. As a result, the resin composition of the present invention satisfies the condition of the following formula (1), which is a predetermined first condition indicating the change in the shape of the resin dome 30 over time, when the height (the distance perpendicular to the surface of the silicon wafer 40) from the contact surface of the resin dome 30 with the silicon wafer 40 to the apex of the resin dome 60 seconds after completion of dispensing _{is H1} , and the height (the distance perpendicular to the surface of the silicon wafer 40) from the contact surface of the resin dome 20 with the silicon wafer 30 to the apex of the resin dome 180 seconds after completion of dispensing is _H2 .
0.15<H ₂ /H ₁ <0.90 (1)

In the condition of the above formula (1), _H2 / _H1 satisfies 0.15< _H2 /H1, preferably 0.20<H2/ _H1 , more preferably 0.25< _H2 / _H1 , still more preferably 0.30< _H2 / _H1 , and particularly preferably 0.33< _H2 / _H1 . On the other hand, _H2 / _H1 satisfies _H2 / _H1 <0.90 _, preferably _H2 / _H1 <0.85 _, and particularly preferably _H2 / _H1 <0.82.

By satisfying the conditions of formula (1) above, the resin composition of the present invention can, in one embodiment, be characterized by good dispensability. Because of its good dispensability, the resin composition can be smoothly discharged from the discharge port 15 (nozzle discharge portion 23) of the syringe 10 filled with the resin composition, and backflow is less likely to occur, resulting in good workability.

Furthermore, by satisfying the condition of formula (1) above, the resin composition of the present invention can, in one embodiment, be characterized by good dischargeability. Good dischargeability results in good liquid drainage, making it difficult for liquid separation or resin dripping to occur, and making it possible to dispense the resin composition with a precise resin supply amount. Liquid drainage refers to the property whereby the resin composition quickly stops being discharged from the nozzle discharge portion 23 when dispensing is stopped. Furthermore, liquid drainage refers to the property whereby the resin composition discharged from the nozzle discharge portion 23 easily separates from the discharge port 15 without adhering to it.

Furthermore, by satisfying the condition of formula (1) above, the resin composition of the present invention can, in one embodiment, be characterized by good resin flow properties. Good resin flow properties make it difficult for unfilled areas to occur in the mold, and resin leakage from the mold during compression molding is also unlikely, resulting in excellent compression moldability.

Furthermore, the diameter _L0 of the contact surface of the resin dome 30 with the silicon wafer 40 increases over time after dispensing. As a result, the resin composition of the present invention preferably further satisfies the condition of the following formula (2) as a second predetermined condition indicating the change in the shape of the resin dome 30 over time, where _L1 is the diameter of the contact surface of the resin dome 30 with the silicon wafer 40 60 seconds after completion of dispensing, and _L2 is the diameter of the contact surface of the resin dome 30 with the silicon wafer 40 180 seconds after completion of dispensing.
0.40<L ₁ /L ₂ <0.96 (2)

In the condition of the above formula (2), _L1 / _L2 satisfies 0.40< _L1 / _L2 , preferably 0.45< _L1 / _L2 , and particularly preferably 0.48< _L1 /L2. On the other hand, _L1 / _L2 satisfies _L1 / _L2 <0.96, preferably _{L1 /L2 <} 0.94, more preferably _L1 / _L2 <0.92, and particularly preferably _L1 / _L2 <0.90.

In one embodiment, the resin composition of the present invention satisfies the condition of formula (2) above, thereby further improving the dispensability, discharge workability, and resin flowability of the resin composition.

Note that from the time dispensing is completed until 180 seconds later, the temperature remains at 23°C, the same as when dispensing.

The viscosity of the resin composition of the present invention at 25°C is typically 1 Pa·s or more, preferably 2.5 Pa·s or more, 10 Pa·s or more, more preferably 30 Pa·s or more, 50 Pa·s or more, even more preferably 80 Pa·s or more, 90 Pa·s or more, still more preferably 100 Pa·s or more, 110 Pa·s or more, and particularly preferably 120 Pa·s or more, 130 Pa·s or more, from the viewpoint of further improving resin flowability and further preventing resin leakage from the mold during compression molding. Furthermore, from the viewpoint of further improving dispensability and further preventing backflow, the upper limit of the viscosity of the resin composition at 25°C is typically 2000 Pa·s or less, preferably 1000 Pa·s or less, 900 Pa·s or less, preferably 800 Pa·s or less, 700 Pa·s or less, preferably 650 Pa·s or less, 600 Pa·s or less, preferably 500 Pa·s or less, 450 Pa·s or less, particularly preferably 400 Pa·s or less, 380 Pa·s or less. The above viscosity can be measured using an E-type viscometer.

In the present invention, the resin composition may contain components selected from (A) a thermosetting resin, (B) an inorganic filler, (C) a radically polymerizable compound, (D) a radical polymerization initiator, (E) a thermoplastic resin, (F) a curing accelerator, (G) a polyether skeleton-containing compound, (H) other additives, and (I) an organic solvent. By selecting and varying the contents of these components, those skilled in the art can adjust the resin composition to satisfy the conditions of formulas (1) and (2) above. Each component contained in the resin composition is described in detail below.

<(A) Thermosetting resin>
In the present invention, the resin composition may contain (A) a thermosetting resin. As the thermosetting resin, a thermosetting resin that can be used as a sealing material for electronic devices can be used. Examples of (A) the thermosetting resin include epoxy resin, epoxy acrylate resin, urethane acrylate resin, urethane resin, cyanate resin, benzoxazine resin, unsaturated polyester resin, phenol resin, melamine resin, and silicone resin.

<(A-1) Epoxy Resin>
In the present invention, the resin composition may contain (A-1) an epoxy resin as the (A) thermosetting resin. (A-1) Epoxy resin means a resin having an epoxy group.

(A-1) Examples of epoxy resins include bixylenol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenol AF-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins having a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Epoxy resins may be used alone or in combination of two or more types.

In the present invention, the resin composition preferably contains, as the epoxy resin (A-1), an epoxy resin having two or more epoxy groups per molecule. From the perspective of significantly achieving the desired effects of the present invention, the proportion of the epoxy resin having two or more epoxy groups per molecule relative to 100% by mass of the non-volatile components of the epoxy resin (A-1) is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more.

(A-1) Epoxy resins include those that are liquid at a temperature of 25°C (hereinafter sometimes referred to as "liquid epoxy resins") and those that are solid at a temperature of 25°C (hereinafter sometimes referred to as "solid epoxy resins"). In the present invention, the resin composition may contain only solid epoxy resins as (A-1) epoxy resins, only liquid epoxy resins, or a combination of liquid and solid epoxy resins; however, it is more preferable for the resin composition to contain a liquid epoxy resin, and it is particularly preferable for the resin composition to contain only liquid epoxy resins as (A-1) epoxy resins.

Preferably, the liquid epoxy resin is one having two or more epoxy groups per molecule.

Preferred liquid epoxy resins are glycerol-type epoxy resins, bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol AF-type epoxy resins, naphthalene-type epoxy resins, glycidyl ester-type epoxy resins, glycidyl amine-type epoxy resins, phenol novolac-type epoxy resins, alicyclic epoxy resins having an ester skeleton, cyclohexanedimethanol-type epoxy resins, cycloaliphatic glycidyl ethers, and epoxy resins having a butadiene structure, with glycerol-type epoxy resins, cycloaliphatic glycidyl ethers, bisphenol A-type epoxy resins, and bisphenol F-type epoxy resins being more preferred.

Specific examples of liquid epoxy resins include Nagase ChemteX's "EX-992L," Mitsubishi Chemical's "YX7400," and DIC's "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resins); Mitsubishi Chemical's "828US," "828EL," "jER828EL," "825," and "Epikote 828EL" (bisphenol A-type epoxy resins); and Mitsubishi Chemical's "jER807" and "1750" "(bisphenol F type epoxy resin); "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", and "604" (glycidylamine type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycilol type epoxy resin) manufactured by ADEKA Corporation; "EP-3950L" and "EP-3980S" (glycidylamine type epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (di Cyclopentadiene-type epoxy resin); "ZX1059" (a mixture of bisphenol A-type epoxy resin and bisphenol F-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "EX-721" (glycidyl ester-type epoxy resin) manufactured by Nagase ChemteX Corporation; "EX-991L" (an epoxy resin containing an alkyleneoxy skeleton) manufactured by Nagase ChemteX Corporation; "Celloxide 2021P" (an alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation; Examples include Daicel's "PB-3600," Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure); Nippon Steel Chemical & Material's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane-type epoxy resins); Osaka Gas Chemicals' "EG-280" (fluorene structure-containing epoxy resin); and Nagase ChemteX's "EX-201" (cyclic aliphatic glycidyl ether).

As a solid epoxy resin, a solid epoxy resin having three or more epoxy groups per molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups per molecule is more preferred.

Preferred solid epoxy resins include bixylenol-type epoxy resins, naphthalene-type epoxy resins, naphthalene-type tetrafunctional epoxy resins, naphthol novolac-type epoxy resins, cresol novolac-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol-type epoxy resins, biphenyl-type epoxy resins, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, phenol aralkyl-type epoxy resins, tetraphenylethane-type epoxy resins, phenolphthalimidine-type epoxy resins, and phenolphthalein-type epoxy resins.

Specific examples of solid epoxy resins include DIC Corporation's "HP4032H" (naphthalene-type epoxy resin); DIC Corporation's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC Corporation's "N-690" (cresol novolac-type epoxy resin); DIC Corporation's "N-695" (cresol novolac-type epoxy resin); DIC Corporation's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene-type epoxy resins); and DIC Corporation's "EXA-73" 11", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin); "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "ESN475V" manufactured by Nippon Steel Chemical & Material Co., Ltd. (naphthalene-type epoxy resin); "ESN485" (naphthol-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN375" (dihydroxynaphthalene-type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YX4000HK", and "YL7890" (bixylenol-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL6121" (biphenyl-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX8800" (anthracene-type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX77" manufactured by Mitsubishi Chemical Corporation Examples include "00" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "WHR991S" (phenolphthalimidine type epoxy resin) manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more types.

The epoxy equivalent of the (A-1) epoxy resin is preferably 50 g/eq. to 5,000 g/eq., more preferably 50 g/eq. to 3,000 g/eq., even more preferably 80 g/eq. to 2,000 g/eq., and even more preferably 110 g/eq. to 1,000 g/eq. The epoxy equivalent is the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

From the viewpoint of significantly achieving the desired effects of the present invention, the weight-average molecular weight (Mw) of the (A-1) epoxy resin is preferably 100 to 5,000, more preferably 250 to 3,000, and even more preferably 400 to 1,500. The weight-average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

The content of the (A-1) epoxy resin in the resin composition is not particularly limited, but is, when all non-volatile components in the resin composition are taken as 100% by mass, for example, 0% by mass or more, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and particularly preferably 3% by mass or more, and preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less. When all non-volatile components in the resin composition other than the (B) inorganic filler are taken as 100% by mass, the content is, for example, 0% by mass or more, 1% by mass or more, preferably 10% by mass or more, more preferably 20% by mass or more, and particularly preferably 30% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, and particularly preferably 80% by mass or less.

<(A-2) Epoxy Curing Agent>
In the present invention, when the resin composition contains an epoxy resin (A-1) as the thermosetting resin (A), it may further contain an epoxy curing agent (A-2) as an optional component. The epoxy curing agent (A-2) functions as an epoxy resin curing agent that reacts with the epoxy resin (A-1) to cure the resin composition.

The (A-2) epoxy curing agent is not particularly limited, but examples include active ester curing agents, phenolic curing agents, carbodiimide curing agents, acid anhydride curing agents, amine curing agents, benzoxazine curing agents, cyanate ester curing agents, and thiol curing agents. (A-2) epoxy curing agents may be used alone or in combination of two or more. (A-2) epoxy curing agent preferably includes an epoxy curing agent selected from active ester curing agents and phenolic curing agents.

Active ester curing agents that are preferably used are generally compounds that have two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds.

Preferably, the active ester curing agent is one obtained by the condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxy compound and/or a thiol compound. From the perspective of improving heat resistance in particular, active ester curing agents obtained from a carboxylic acid compound and a hydroxy compound are preferred, and active ester curing agents obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound are even more preferred.

Examples of active ester curing agents include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenolic or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specific examples of active ester curing agents include dicyclopentadiene-type active ester curing agents, naphthalene-type active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated product of phenol novolac, and active ester curing agents containing a benzoylated product of phenol novolac. Among these, at least one selected from dicyclopentadiene-type active ester curing agents and naphthalene-type active ester curing agents is more preferred. Of the dicyclopentadiene-type active ester curing agents, active ester curing agents containing a dicyclopentadiene-type diphenol structure are preferred.

Commercially available active ester curing agents include "EXB9451," "EXB9460," "EXB9460S," "EXB-8000L," "EXB-8000L-65M," "EXB-8000L-65TM," "HPC-8000L-65TM," "HPC-8000," "HPC-8000-65T," "HPC-8000H," and "HPC-8000H-65TM" (manufactured by DIC Corporation), which contain dicyclopentadiene-type diphenol structures; and "EXB-8151-62T," "EXB-8100L-65T," "EXB-8150-60T," and "EXB-81 50-62T, "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T" (manufactured by DIC Corporation); a phosphorus-containing active ester curing agent such as "EXB9401" (manufactured by DIC Corporation); an active ester curing agent which is an acetylated phenol novolac such as "DC808" (manufactured by Mitsubishi Chemical Corporation); active ester curing agents which are benzoylated phenol novolac such as "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and an active ester curing agent containing a styryl group and a naphthalene structure such as "PC1300-02-65MA" (manufactured by Air Water Inc.).

Phenol-based curing agents include those that have one or more, preferably two or more, hydroxyl groups bonded to an aromatic ring such as a benzene ring or a naphthalene ring per molecule. Of these, compounds that have a hydroxyl group bonded to a benzene ring are preferred.

Specific examples of phenolic curing agents include "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "TD-2090," "TD-2090-60M," "LA-7052," "LA-7054," "LA-1356," "LA-3018," "LA-3018-50P," "EXB-9500," "HPC-9500," "KA-1160," "KA-1163," and "KA-1165" manufactured by DIC Corporation; "GDP-6115L," "GDP-6115H," and "ELPC75" manufactured by Gunei Chemical Co., Ltd.; and "2,2-diallyl bisphenol A" manufactured by Sigma-Aldrich.

Carbodiimide-based curing agents include curing agents having one or more, preferably two or more, carbodiimide structures in one molecule, such as aliphatic biscarbodiimides such as tetramethylene-bis(t-butylcarbodiimide) and cyclohexane-bis(methylene-t-butylcarbodiimide); aromatic biscarbodiimides such as phenylene-bis(xylylcarbodiimide); and aliphatic polycarbodiimides such as polyhexamethylenecarbodiimide, polytrimethylhexamethylenecarbodiimide, polycyclohexylenecarbodiimide, poly(methylenebiscyclohexylenecarbodiimide), and poly(isophoronecarbodiimide). Examples of polycarbodiimides include aromatic polycarbodiimides such as poly(phenylenecarbodiimide), poly(naphthylenecarbodiimide), poly(tolylenecarbodiimide), poly(methyldiisopropylphenylenecarbodiimide), poly(triethylphenylenecarbodiimide), poly(diethylphenylenecarbodiimide), poly(triisopropylphenylenecarbodiimide), poly(diisopropylphenylenecarbodiimide), poly(xylylenecarbodiimide), poly(tetramethylxylylenecarbodiimide), poly(methylenediphenylenecarbodiimide), and poly[methylenebis(methylphenylene)carbodiimide].

Commercially available carbodiimide curing agents include, for example, "Carbodilite V-02B," "Carbodilite V-03," "Carbodilite V-04K," "Carbodilite V-07," and "Carbodilite V-09" manufactured by Nisshinbo Chemical Inc.; and "Stavaxol P," "Stavaxol P400," and "Hykasil 510" manufactured by Rhein Chemie AG.

Acid anhydride curing agents include those having one or more acid anhydride groups in one molecule, with those having two or more acid anhydride groups in one molecule being preferred. Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of suitable acid anhydrides include polymeric acid anhydrides such as biphenyltetracarboxylic dianhydride, naphthalenetetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4'-diphenylsulfonetetracarboxylic dianhydride, 1,3,3a,4,5,9b-hexahydro-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-C]furan-1,3-dione, ethylene glycol bis(anhydrotrimellitate), and styrene-maleic acid resins, which are copolymers of styrene and maleic acid. Commercially available acid anhydride curing agents include "HNA-100," "MH-700," "MTA-15," "DDSA," and "OSA" manufactured by New Japan Chemical Co., Ltd.; "YH-306" and "YH-307" manufactured by Mitsubishi Chemical Corporation; and "HN-2200" and "HN-5500" manufactured by Hitachi Chemical Co., Ltd.

Amine-based curing agents include those containing one or more, preferably two or more, amino groups in one molecule. Examples include aliphatic amines, polyether amines, alicyclic amines, and aromatic amines. Of these, aromatic amines are preferred from the perspective of achieving the desired effects of the present invention. Amine-based curing agents are preferably primary or secondary amines, with primary amines being more preferred. Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, and 2,2-bis(3-amino-4-hydroxyphenyl)propanol. propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, and the like. Commercially available amine-based curing agents may be used, such as "SEIKACURE-S" manufactured by Seika Corporation, "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

Specific examples of benzoxazine-based curing agents include "JBZ-OP100D" and "ODA-BOZ" manufactured by JFE Chemical Corporation; "HFB2006M" manufactured by Showa Highpolymer Co., Ltd.; and "P-d" and "F-a" manufactured by Shikoku Chemicals Corporation.

Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include Lonza Japan's "PT30" and "PT60" (both phenol novolac-type multifunctional cyanate ester resins), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazinated to form a trimer).

Examples of thiol-based curing agents include trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), and tris(3-mercaptopropyl)isocyanurate.

The reactive group equivalent of the epoxy curing agent (A-2) is preferably 50 g/eq. to 3000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 100 g/eq. to 500 g/eq., and particularly preferably 100 g/eq. to 300 g/eq. The reactive group equivalent is the mass of the curing agent per equivalent of reactive groups.

The content of (A-2) epoxy curing agent in the resin composition is not particularly limited, but is, for example, 0% by mass or more, 0.01% by mass or more, preferably 0.1% by mass or more, more preferably 1% by mass or more, and particularly preferably 2% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 7% by mass or less, when all non-volatile components in the resin composition other than (B) inorganic filler are taken as 100% by mass.

<(B) Inorganic filler>
In the present invention, the resin composition may contain (B) an inorganic filler as an optional component.

(B) An inorganic compound is used as the inorganic filler material. Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. (B) The inorganic filler may be used alone or in combination of two or more types.

(B) The 50% cumulative diameter D50 of the inorganic filler is preferably 0.2 μm or more, more preferably 0.3 μm or more, and particularly preferably 0.4 μm or more, and is preferably 15 μm or less, more preferably 12 μm or less, and even more preferably 10 μm or less. If the 50% cumulative diameter D50 of the inorganic filler (B) is too small, dispensability may decrease and backflow may become more likely to occur.

The 90% cumulative diameter D90 of (B) inorganic filler is preferably 2 μm or more, more preferably 3 μm or more, particularly preferably 3.5 μm or more, and is preferably 30 μm or less, more preferably 27 μm or less, and even more preferably 25 μm or less. Such a small 90% cumulative diameter D90 indicates that (C) inorganic filler does not contain large particles. If the 90% cumulative diameter D90 of (B) inorganic filler is too small, dispensability may decrease and backflow may become more likely to occur.

(B) The ratio D50/D90 of the 50% cumulative diameter D50 to the 90% cumulative diameter D90 of the inorganic filler is preferably 0.2 or more, more preferably 0.3 or more, and particularly preferably 0.35 or more, and is preferably 0.8 or less, more preferably 0.7 or less, and even more preferably 0.65 or less.

(B) The difference between the 50% cumulative diameter D50 and the 90% cumulative diameter D90 of the inorganic filler (D90 - D50) is preferably 2 μm or more, more preferably 2.5 μm or more, and particularly preferably 3 μm or more, and is preferably 20 μm or less, more preferably 18 μm or less, and even more preferably 16 μm or less.

The 50% cumulative diameter D50 and 90% cumulative diameter D90 of (B) inorganic filler can be measured using a laser diffraction/scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of (B) inorganic filler is created using a laser diffraction/scattering particle size distribution analyzer. The particle diameter at which the cumulative frequency from the smallest diameter side is 50% (i.e., median diameter) can be taken as the 50% cumulative diameter D50. The particle diameter at which the cumulative frequency from the smallest diameter side is 90% can be taken as the 90% cumulative diameter D90. A measurement sample can be prepared by weighing 100 mg of (B) inorganic filler and 10 g of methyl ethyl ketone into a vial and ultrasonically dispersing for 10 minutes. The measurement sample is subjected to a laser diffraction particle size distribution analyzer using blue and red light source wavelengths and a flow cell system to measure the volumetric particle size distribution of the inorganic filler (B). The 50% cumulative diameter D50 and 90% cumulative diameter D90 can then be calculated from the resulting particle size distribution. Examples of laser diffraction particle size distribution analyzers include the "LA-960" manufactured by Horiba, Ltd.

From the viewpoint of significantly achieving the desired effects of the present invention, the specific surface area of (B) inorganic filler is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more. There is no particular upper limit, but it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area is obtained according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

(B) Commercially available inorganic fillers include, for example, "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumikin Materials Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," and "YA010C" manufactured by Admatechs Co., Ltd.; "UFP-30" manufactured by Denka Company Limited; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; and "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.

(B) From the viewpoint of improving moisture resistance and dispersibility, it is preferable that the inorganic filler be treated with a surface treatment agent. Examples of surface treatment agents include fluorine-containing silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate coupling agents. Furthermore, one type of surface treatment agent may be used alone, or two or more types may be used in any combination.

Commercially available surface treatment agents include, for example, Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

The degree of surface treatment with the surface treatment agent preferably falls within a specified range from the viewpoint of improving the dispersibility of the (B) inorganic filler. Specifically, 100 parts by mass of the (B) inorganic filler is preferably surface-treated with 0.2 to 5 parts by mass of the surface treatment agent, more preferably 0.2 to 3 parts by mass, and even more preferably 0.3 to 2 parts by mass.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the (B) inorganic filler. From the viewpoint of improving the dispersibility of the (B) inorganic filler, the amount of carbon per unit surface area of the (B) inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the resin sheet layer, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less.

The carbon content per unit surface area of the (B) inorganic filler can be measured after the surface-treated (B) inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the (B) inorganic filler that has been surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the carbon content per unit surface area of the (B) inorganic filler can be measured using a carbon analyzer. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba, Ltd. can be used.

The content of (B) inorganic filler in the resin composition is not particularly limited. However, from the perspective of more significantly achieving the desired effects of the present invention, assuming that the non-volatile components in the resin composition are 100% by mass, it is, for example, 0% by mass or more, 1% by mass or more, preferably 10% by mass or more, 20% by mass or more, more preferably 30% by mass or more, 40% by mass or more, even more preferably 50% by mass or more, 60% by mass or more, still more preferably 65% by mass or more, 70% by mass or more, particularly preferably 75% by mass or more, 78% by mass or more, with the upper limit being preferably 95% by mass or less, more preferably 92% by mass or less, even more preferably 90% by mass or less, and particularly preferably 89% by mass or less. If the content of (B) inorganic filler is too high, dispensability may be reduced and backflow may be more likely to occur.

<(C) Silane Coupling Agent>
In the present invention, the resin composition may contain (C) a silane coupling agent as an optional component other than the components (A) and (B).

(C) Examples of silane coupling agents include aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, alkoxysilane compounds, organosilazane compounds, and titanate coupling agents. Among these, epoxysilane coupling agents containing epoxy groups and mercaptosilane coupling agents containing mercapto groups are preferred. Furthermore, one type of silane coupling agent may be used alone, or two or more types may be used in combination.

(C) As the silane coupling agent, for example, commercially available products may be used. Examples of commercially available silane coupling agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and "SZ-31" manufactured by Shin-Etsu Chemical Co., Ltd. " (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd.'s "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM-4803" (long-chain epoxy-type silane coupling agent), Shin-Etsu Chemical Co., Ltd.'s "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM503" (3-methacryloxypropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd.'s "KBM5783", etc.

The amount of (C) silane coupling agent is not particularly limited, but is, when all non-volatile components in the resin composition are taken as 100% by mass, for example, 0% by mass or more, 0.0001% by mass or more, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.05% by mass or more, and preferably 1% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.3% by mass or less. When all non-volatile components in the resin composition other than (B) inorganic filler are taken as 100% by mass, the amount is, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.5% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less.

<(D) Curing Accelerator>
The resin composition of the present invention may contain a curing accelerator (D) as an optional component other than the components (A) to (C). The curing accelerator (D) functions as a curing catalyst that accelerates the curing of the resin composition.

(D) Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. Of these, imidazole-based curing accelerators are preferred. One type of curing accelerator may be used alone, or two or more types may be used in combination.

Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, 1,8-diazabicyclo[5,4,0]undecene-7,4-dimethylaminopyridine, and 2,4,6-tris(dimethylaminomethyl)phenol, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

Examples of imidazole curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2, 4-Diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, Examples of the imidazole compounds include phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins. 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole are preferred.

Commercially available imidazole-based curing accelerators may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation, and "Curezol 2MZ," "2E4MZ," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," "Cl1Z-A," "2MZ-OK," "2MA-OK," "2MA-OK-PW," and "2PHZ" manufactured by Shikoku Chemicals Corporation.

Examples of guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

The content of (D) curing accelerator in the resin composition is not particularly limited, but is, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more, and preferably 5% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, when all non-volatile components in the resin composition other than (B) inorganic filler are taken as 100% by mass.

<(E) Radically Polymerizable Compound>
The resin composition of the present invention may contain (E) a radically polymerizable compound as an optional component other than the components (A) to (D).

The (E) radical polymerizable compound may be a compound having an ethylenically unsaturated bond. Examples of such (E) radical polymerizable compounds include compounds having a radical polymerizable group such as a vinyl group, allyl group, 1-butenyl group, 2-butenyl group, acryloyl group, methacryloyl group, fumaroyl group, maleoyl group, vinylphenyl group, styryl group, cinnamoyl group, and maleimide group (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl group). One type of (E) radical polymerizable compound may be used alone, or two or more types may be used in combination.

Specific examples of (E) radically polymerizable compounds include (meth)acrylic radically polymerizable compounds having one or more acryloyl groups and/or methacryloyl groups; styrene radically polymerizable compounds having one or more vinyl groups directly bonded to an aromatic carbon atom; allyl radically polymerizable compounds having one or more allyl groups; and maleimide radically polymerizable compounds having one or more maleimide groups. Of these, (meth)acrylic radically polymerizable compounds are preferred.

The (E) radically polymerizable compound preferably contains a polyalkylene oxide structure. By using the (E) radically polymerizable compound containing a polyalkylene oxide structure, the flexibility of the cured product of the resin composition of the present invention can be increased, reducing warping of the cured product and improving adhesion between the cured product and the conductor layer.

The polyalkylene oxide structure can be represented by the formula -(R ^f O) _n -. In this formula, n usually represents an integer of 2 or more. This integer n is preferably 4 or more, more preferably 9 or more, even more preferably 11 or more, and usually 101 or less, preferably 90 or less, more preferably 68 or less, and even more preferably 65 or less. In formula (4), R ^f each independently represents an alkylene group which may have a substituent. The number of carbon atoms in the alkylene group is preferably 1 or more, more preferably 2 or more, and preferably 6 or less, more preferably 5 or less, even more preferably 4 or less, even more preferably 3 or less, and particularly preferably 2. Specific examples of the polyalkylene oxide structure include a polyethylene oxide structure, a polypropylene oxide structure, a poly-n-butylene oxide structure, a poly(ethylene oxide-co-propylene oxide) structure, a poly(ethylene oxide-ran-propylene oxide) structure, a poly(ethylene oxide-alt-propylene oxide) structure, and a poly(ethylene oxide-block-propylene oxide) structure.

The number of polyalkylene oxide structures contained in one molecule of the (E) radical polymerizable compound may be 1 or 2 or more. The number of polyalkylene oxide structures contained in one molecule of the (E) radical polymerizable compound is preferably 2 or more, more preferably 4 or more, even more preferably 9 or more, particularly preferably 11 or more, and is preferably 101 or less, more preferably 90 or less, even more preferably 68 or less, particularly preferably 65 or less. When the (E) radical polymerizable compound contains two or more polyalkylene oxide structures in one molecule, these polyalkylene oxide structures may be the same or different.

Commercially available examples of (E) radically polymerizable compounds containing a polyalkylene oxide structure include monofunctional acrylates "AM-90G," "AM-130G," and "AMP-20GY," bifunctional acrylates "A-1000," "A-B1206PE," "A-BPE-20," and "A-BPE-30," monofunctional methacrylates "M-20G," "M-40G," "M-90G," "M-130G," and "M-230G," as well as bifunctional methacrylates "23G," "BPE-900," "BPE-1300N," and "1206PE," all manufactured by Shin-Nakamura Chemical Co., Ltd. Other examples include Kyoeisha Chemical's "Light Ester BC," "Light Ester 041MA," "Light Acrylate EC-A," and "Light Acrylate EHDG-AT"; Hitachi Chemical's "FA-023M"; and NOF Corporation's "BLEMMER (registered trademark) PME-4000," "BLEMMER (registered trademark) 50POEO-800B," "BLEMMER (registered trademark) PLE-200," "BLEMMER (registered trademark) PLE-1300," "BLEMMER (registered trademark) PSE-1300," "BLEMMER (registered trademark) 43PAPE-600B," and "BLEMMER (registered trademark) ANP-300." Of these, "M-130G" (n is 13 on average) having a polyalkylene oxide structure (specifically, a polyethylene oxide structure) and "M-230G" (n is 23 on average) having a polyalkylene oxide structure (specifically, a polyethylene oxide structure) are preferred.

The ethylenically unsaturated bond equivalent of the (E) radically polymerizable compound is preferably 20 g/eq. to 3000 g/eq., more preferably 50 g/eq. to 2500 g/eq., even more preferably 70 g/eq. to 2000 g/eq., and particularly preferably 90 g/eq. to 1500 g/eq. The ethylenically unsaturated bond equivalent represents the mass of the radically polymerizable compound per equivalent of ethylenically unsaturated bond.

The weight average molecular weight (Mw) of the (E) radically polymerizable compound is preferably 150 or more, more preferably 250 or more, even more preferably 400 or more, and preferably 40,000 or less, more preferably 10,000 or less, even more preferably 5,000 or less, and particularly preferably 3,000 or less.

The content of the (E) radical polymerizable compound in the resin composition is not particularly limited, but is, when all non-volatile components in the resin composition are taken as 100% by mass, for example, 0% by mass or more, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, and particularly preferably 3% by mass or more, and preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. When all non-volatile components in the resin composition other than the (B) inorganic filler are taken as 100% by mass, the content is, for example, 0% by mass or more, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more, and preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less.

<(F) Radical Polymerization Initiator>
The resin composition of the present invention may further contain (F) a radical polymerization initiator as an optional component. As the (F) radical polymerization initiator, a thermal polymerization initiator that generates free radicals upon heating is preferred. The (F) radical polymerization initiator may be used alone or in combination of two or more types.

(F) Examples of radical polymerization initiators include peroxide-based radical polymerization initiators and azo-based radical polymerization initiators. Among these, peroxide-based radical polymerization initiators are preferred.

Examples of peroxide radical polymerization initiators include hydroperoxide compounds such as 1,1,3,3-tetramethylbutyl hydroperoxide; dialkyl peroxide compounds such as tert-butylcumyl peroxide, di-tert-butyl peroxide, di-tert-hexyl peroxide, dicumyl peroxide, 1,4-bis(1-tert-butylperoxy-1-methylethyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(tert-butylperoxy)-3-hexyne; dilauroyl peroxide, didecanoyl peroxide, dicyclohexyl peroxydicarbonate, and bis(4-tert-butylcyclohexyl)peroxydica; Examples of peroxyester compounds include diacyl peroxide compounds such as tert-butyl peroxyacetate, tert-butyl peroxybenzoate, tert-butylperoxyisopropyl monocarbonate, tert-butylperoxy-2-ethylhexanoate, tert-butylperoxyneodecanoate, tert-hexylperoxyisopropyl monocarbonate, tert-butyl peroxylaurate, (1,1-dimethylpropyl) 2-ethylperhexanoate, tert-butyl 2-ethylperhexanoate, tert-butyl 3,5,5-trimethylperhexanoate, tert-butylperoxy-2-ethylhexyl monocarbonate, and tert-butylperoxymaleic acid.

Examples of azo radical polymerization initiators include azonitrile compounds such as 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 1-[(1-cyano-1-methylethyl)azo]formamide, and 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile; 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide], and 2,2'-azobis[2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide]. azo amide compounds such as 2,2'-azobis[2-methyl-N-[2-(1-hydroxybutyl)]-propionamide], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propionamide], 2,2'-azobis(2-methylpropionamide) dihydrate, 2,2'-azobis[N-(2-propenyl)-2-methylpropionamide], 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(N-cyclohexyl-2-methylpropionamide); alkyl azo compounds such as 2,2'-azobis(2,4,4-trimethylpentane) and 2,2'-azobis(2-methylpropane); and the like.

The (F) radical polymerization initiator is preferably one that is active at medium temperatures. Specifically, the (F) radical polymerization initiator preferably has a 10-hour half-life temperature T10 (°C) within a specific low temperature range. The 10-hour half-life temperature T10 is preferably 50°C to 110°C, more preferably 50°C to 100°C, and even more preferably 50°C to 80°C. Commercially available (F) radical polymerization initiators include "Luperox 531M80" manufactured by Arkema Fuji Co., Ltd., "Perhexyl (registered trademark) O" manufactured by NOF Corporation, and "MAIB" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

The content of the (F) radical polymerization initiator in the resin composition is not particularly limited, but is, when all non-volatile components in the resin composition are taken as 100% by mass, for example, 0% by mass or more, 0.0001% by mass or more, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and particularly preferably 0.05% by mass or more, and preferably 1% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less. When all non-volatile components in the resin composition other than the (B) inorganic filler are taken as 100% by mass, the content is, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and particularly preferably 0.3% by mass or more, and preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less.

<(G) Polyether Skeleton-Containing Compound>
The resin composition of the present invention may contain (G) a polyether skeleton-containing compound as an optional component other than the components (A) to (F). The (G) polyether skeleton-containing compound may be used alone or in combination of two or more.

The (G) polyether skeleton-containing compound is a polymer compound having a polyether skeleton. The polyether skeleton contained in the (G) polyether skeleton-containing compound is preferably a polyoxyalkylene skeleton composed of one or more monomer units selected from ethylene oxide units and propylene oxide units. Therefore, the (G) polyether skeleton-containing compound preferably does not contain a polyether skeleton containing a monomer unit having 4 or more carbon atoms, such as a butylene oxide unit or a phenylene oxide unit.

The (G) polyether skeleton-containing compound may contain a silicone skeleton. Examples of silicone skeletons include polydialkylsiloxane skeletons such as polydimethylsiloxane skeletons; polydiarylsiloxane skeletons such as polydiphenylsiloxane skeletons; polyalkylarylsiloxane skeletons such as polymethylphenylsiloxane skeletons; polydialkyl-diarylsiloxane skeletons such as polydimethyl-diphenylsiloxane skeletons; polydialkyl-alkylarylsiloxane skeletons such as polydimethyl-methylphenylsiloxane skeletons; and polydiaryl-alkylarylsiloxane skeletons such as polydiphenyl-methylphenylsiloxane skeletons. Polydialkylsiloxane skeletons are preferred, and polydimethylsiloxane skeletons are particularly preferred. The (G) polyether skeleton-containing compound containing a silicone skeleton may be, for example, polyoxyalkylene-modified silicone, alkyl-etherified polyoxyalkylene-modified silicone (polyoxyalkylene-modified silicone in which at least a portion of the polyether skeleton terminals are alkoxy groups), etc. Furthermore, the (G) polyether skeleton-containing compound may contain a hydroxy group.

(G) Examples of polyether skeleton-containing compounds include linear polyoxyalkylene glycols (linear polyalkylene glycols) such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol; polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene polyoxypropylene glyceryl ether, polyoxyethylene trimethylolpropane ether, polyoxypropylene trimethylolpropane ether, polyoxyethylene polyoxypropylene trimethylolpropane ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyethylene polyoxypropylene diglyceryl ether, polyoxyethylene pentaerythritol ether, polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene sorbitol ... polyoxyalkylene glycols (polyalkylene glycols) such as multi-chain polyoxyalkylene glycols (multi-chain polyalkylene glycols) such as dipropylene sorbite and polyoxyethylene polyoxypropylene sorbite; polyoxyalkylene alkyl ethers such as polyoxyethylene monoalkyl ethers, polyoxyethylene dialkyl ethers, polyoxypropylene monoalkyl ethers, polyoxypropylene dialkyl ethers, polyoxyethylene polyoxypropylene monoalkyl ethers and polyoxyethylene polyoxypropylene dialkyl ethers; polyoxyalkylene esters such as polyoxyethylene monoesters, polyoxyethylene diesters, polypropylene glycol monoesters, polypropylene glycol diesters, polyoxyethylene polyoxypropylene monoesters and polyoxyethylene polyoxypropylene diesters (including acetate esters, propionate esters, butyrate esters, (meth)acrylate esters, etc.) polyoxyalkylene alkyl ether esters (including acetate esters, propionate esters, butyrate esters, (meth)acrylate esters, etc.) such as polyoxyethylene monoesters, polyoxyethylene diesters, polyoxypropylene monoesters, polyoxypropylene diesters, polyoxyethylene polyoxypropylene monoesters, polyoxyethylene polyoxypropylene diesters, polyoxyethylene alkyl ether esters, polyoxypropylene alkyl ether esters, and polyoxyethylene polyoxypropylene alkyl ether esters; polyoxyalkylene alkylamines such as polyoxyethylene alkylamines, polyoxypropylene alkylamines, and polyoxyethylene polyoxypropylene alkylamines; polyoxyalkylene alkylamides such as polyoxyethylene alkylamides, polyoxypropylene alkylamides, and polyoxyethylene polyoxypropylene alkylamides; polyoxyethylene dimethicone, Examples include polyoxyalkylene-modified silicones such as polyoxypropylene dimethicone, polyoxyethylene polyoxypropylene dimethicone, polyoxyethylene polydimethylsiloxyalkyl dimethicone, polyoxypropylene polydimethylsiloxyalkyl dimethicone, and polyoxyethylene polyoxypropylene polydimethylsiloxyalkyl dimethicone; and alkyl-etherified polyoxyalkylene-modified silicones (polyoxyalkylene-modified silicones in which at least a portion of the polyether skeleton terminals are alkoxy groups) such as polyoxyethylene alkyl ether dimethicone, polyoxypropylene alkyl ether dimethicone, polyoxyethylene polyoxypropylene alkyl ether dimethicone, polyoxyethylene alkyl ether polydimethylsiloxyalkyl dimethicone, and polyoxyethylene polyoxypropylene alkyl ether polydimethylsiloxyalkyl dimethicone.

The number average molecular weight of the (G) polyether skeleton-containing compound is preferably 500 to 40,000, more preferably 500 to 20,000, and even more preferably 500 to 10,000. The weight average molecular weight of the (G) polyether skeleton-containing compound is preferably 500 to 40,000, more preferably 500 to 20,000, and even more preferably 500 to 10,000. The number average molecular weight and weight average molecular weight can be measured as polystyrene-equivalent values by gel permeation chromatography (GPC).

The (G) polyether skeleton-containing compound is preferably liquid at 25°C. The viscosity of the (G) polyether skeleton-containing compound at 25°C is preferably 100,000 mPa·s or less, more preferably 50,000 mPa·s or less, even more preferably 30,000 mPa·s or less, even more preferably 10,000 mPa·s or less, even more preferably 5,000 mPa·s or less, even more preferably 4,000 mPa·s or less, even more preferably 3,000 mPa·s or less, even more preferably 2,000 mPa·s or less, and particularly preferably 1,500 mPa·s or less. The lower limit of the viscosity of the (G) polyether skeleton-containing compound at 25°C is preferably 10 mPa·s or more, more preferably 20 mPa·s or more, even more preferably 30 mPa·s or more, even more preferably 40 mPa·s or more, and particularly preferably 50 mPa·s or more. The viscosity may be measured using a Brookfield viscometer (mPa·s).

(G) Commercially available polyether skeleton-containing compounds include, for example, NOF Corporation's "Pronon #102," "Pronon #104," "Pronon #201," "Pronon #202B," "Pronon #204," "Pronon #208," "Unilube 70DP-600B," and "Unilube 70DP-950B" (polyoxyethylene polyoxypropylene glycol); ADEKA Corporation's "Pluronic L-23," "Pluronic L-31," and "Pluronic L-41." Pluronic L-44, Pluronic L-61, Adeka Pluronic L-62, Pluronic L-64, Pluronic L-71, Pluronic L-72, Pluronic L-101, Pluronic L-121, Pluronic P-84, Pluronic P-85, Pluronic P-103, Pluronic F-68, Pluronic F-88, Pluronic F-108, Pluronic 25R-1, "Pluronic 25R-2", "Pluronic 17R-2", "Pluronic 17R-3", and "Pluronic 17R-4" (polyoxyethylene polyoxypropylene glycol); "KF-6011", "KF-6011P", "KF-6012", "KF-6013", "KF-6015", "KF-6016", "KF-6017", "KF-6017P", "KF-6043", "KF-6004", and "KF35" manufactured by Shin-Etsu Silicone Co., Ltd. 1A," "KF352A," "KF353," "KF354L," "KF355A," "KF615A," "KF945," "KF-640," "KF-642," "KF-643," "KF-644," "KF-6020," "KF-6204," "X22-4515," "KF-6028," "KF-6028P," "KF-6038," "KF-6048," and "KF-6025" (polyoxyalkylene-modified silicone).

The content of the (G) polyether skeleton-containing compound in the resin composition is not particularly limited, but is, when all non-volatile components in the resin composition are taken as 100% by mass, for example, 0% by mass or more, 0.001% by mass or more, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, preferably 5% by mass or less, more preferably 2% by mass or less, and particularly preferably 1% by mass or less. When all non-volatile components in the resin composition other than the (B) inorganic filler are taken as 100% by mass, the content is, for example, 0% by mass or more, 0.1% by mass or more, preferably 0.5% by mass or more, more preferably 1% by mass or more, particularly preferably 5% by mass or more, preferably 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 7% by mass or less.

<(H) Other Additives>
The resin composition of the present invention may contain any additive as a non-volatile component other than the above-mentioned components (A) to (G). Examples of such additives include organic fillers such as rubber particles, polyamide fine particles, and silicone particles; thermoplastic resins such as polycarbonate resins, phenoxy resins, polyvinyl acetal resins, polyolefin resins, polysulfone resins, and polyester resins; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone-based leveling agents and acrylic polymer-based leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone-based antifoaming agents, acrylic-based antifoaming agents, fluorine-based antifoaming agents, and vinyl resin-based antifoaming agents; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; and urea silanes. antioxidants such as hindered phenol antioxidants and hindered amine antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyalkylene-based dispersants, acetylene-based dispersants, silicone-based dispersants, anionic dispersants, and cationic dispersants; and stabilizers such as borate-based stabilizers, titanate-based stabilizers, aluminate-based stabilizers, zirconate-based stabilizers, isocyanate-based stabilizers, carboxylic acid-based stabilizers, and carboxylic acid anhydride-based stabilizers. The additives may be used alone or in combination of two or more kinds in any ratio.

<(I) Organic Solvent>
The resin composition of the present invention may further contain (I) any organic solvent as a volatile component. The (I) organic solvent may be used alone or in combination of two or more types in any ratio. The smaller the amount of solvent, the better. The amount of solvent is preferably 3% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, even more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less, based on 100% by mass of all non-volatile components in the resin composition of the present invention. It is particularly preferable that the solvent is not contained (0% by mass).

<Method of producing resin composition>
The resin composition of the present invention can be produced, for example, by mixing the above-mentioned components. The above-mentioned components may be mixed partially or entirely at the same time, or may be mixed sequentially. In the process of mixing each component, the temperature may be appropriately set, and thus heating and/or cooling may be performed temporarily or throughout. Furthermore, stirring or shaking may be performed in the process of mixing each component.

<Uses of resin composition>
The resin composition of the present invention can be suitably used as a resin composition (encapsulating resin composition) for encapsulating electronic devices such as organic EL devices and semiconductors, and in particular as a resin composition for encapsulating semiconductors (semiconductor encapsulating resin composition), preferably as a resin composition for encapsulating semiconductor chips (semiconductor chip encapsulating resin composition). In addition to encapsulation applications, the resin composition can also be used as an insulating resin composition for insulating layers. For example, the resin composition can be suitably used as a resin composition for forming an insulating layer of a semiconductor chip package (semiconductor chip package insulating layer resin composition) and a resin composition for forming an insulating layer of a circuit board (including a printed wiring board) (circuit board insulating layer resin composition).

From the perspective of utilizing the advantage of being able to improve the resolution of the photosensitive resin composition layer formed on the cured resin composition layer of the present invention, the resin composition of the present invention is preferably used to form a sealing layer or insulating layer of a semiconductor chip package. Examples of semiconductor chip packages include FC-CSP, MIS-BGA package, ETS-BGA package, fan-out type WLP (Wafer Level Package), fan-in type WLP, fan-out type PLP (Panel Level Package), and fan-in type PLP.

The resin composition may also be used as an underfill material, for example, as a molding underfill (MUF) material used after connecting a semiconductor chip to a substrate.

Furthermore, the resin composition can be used in a wide range of applications where resin compositions are used, such as sheet-like laminate materials such as resin sheets and prepregs, solder resists, die bonding materials, hole-filling resins, and component-embedding resins.

<Resin sheet>
The resin sheet has a support and a resin composition layer provided on the support. The resin composition layer is a layer formed from the resin composition of the present invention.

From the perspective of achieving a thinner film, the thickness of the resin composition layer is preferably 600 μm or less, more preferably 500 μm or less. The lower limit of the thickness of the resin composition layer is preferably 1 μm or more, 5 μm or more, more preferably 10 μm or more, even more preferably 50 μm or more, and particularly preferably 100 μm or more.

Furthermore, the thickness of the cured layer obtained by curing this resin composition layer is preferably 600 μm or less, more preferably 500 μm or less. The lower limit of the thickness of the cured layer is preferably 1 μm or more, 5 μm or more, more preferably 10 μm or more, even more preferably 50 μm or more, and particularly preferably 100 μm or more.

Examples of the support include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"); polycarbonate (hereinafter sometimes abbreviated as "PC"); acrylic polymers such as polymethyl methacrylate (hereinafter sometimes abbreviated as "PMMA"); cyclic polyolefins; triacetyl cellulose (hereinafter sometimes abbreviated as "TAC"); polyether sulfide (hereinafter sometimes abbreviated as "PES"); polyether ketone; polyimide; etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil. Of these, copper foil is preferred. The copper foil may be a foil made of the single metal copper, or a foil made of an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

The surface of the support that will be bonded to the resin composition layer may be subjected to a matte finish, corona treatment, antistatic treatment, etc.

The support may also be a support with a release layer, which has a release layer on the surface that bonds with the resin composition layer. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available release agents include alkyd resin-based release agents such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation. Examples of support with a release layer include "Lumirror T60" manufactured by Toray Industries, Inc.; "Purex" manufactured by Teijin Limited; and "Uni-Peel" manufactured by Unitika Ltd.

The thickness of the support is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the overall thickness of the support with a release layer be in the above range.

The resin sheet can be produced, for example, by applying the resin composition of the present invention to a support using a coating device such as a die coater. If necessary, the resin composition of the present invention may be dissolved in an organic solvent to prepare a resin varnish, and the resin sheet may be produced by applying this resin varnish. The use of an organic solvent can adjust the viscosity and improve coatability. When a resin composition or resin varnish of the present invention containing an organic solvent is used, the resin composition or resin varnish of the present invention is typically dried after application to form the resin composition layer of the present invention.

Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. These organic solvents may be used alone or in combination of two or more in any ratio.

Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are typically set so that the organic solvent content in the resin composition layer is 10% by mass or less, and preferably 5% by mass or less. While this varies depending on the boiling point of the organic solvent in the resin composition or resin varnish of the present invention, for example, when using a resin composition or resin varnish of the present invention containing 30% by mass to 60% by mass of organic solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

The resin sheet may optionally include any layer other than the support and the resin composition layer. For example, a protective film similar to that of the support may be provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is, for example, 1 μm to 40 μm. The protective film can prevent the adhesion of dirt and other contaminants to the surface of the resin composition layer, as well as scratches. When the resin sheet has a protective film, the resin sheet can be used by peeling off the protective film. The resin sheet can also be rolled up for storage.

The resin sheet can be suitably used to form an insulating layer in the manufacture of semiconductor chip packages (insulating resin sheet for semiconductor chip packages). For example, the resin sheet can be used to form an insulating layer for a circuit board (insulating layer resin sheet for circuit boards). Examples of packages using such substrates include FC-CSP, MIS-BGA packages, and ETS-BGA packages.

The resin sheet can also be used to encapsulate semiconductor chips (semiconductor chip encapsulation resin sheet). Examples of applicable semiconductor chip packages include fan-out WLP, fan-in WLP, fan-out PLP, and fan-in PLP.

The resin sheet may also be used as a material for the MUF used after connecting the semiconductor chip to the substrate.

In addition, resin sheets can be used in a wide range of other applications that require high insulation reliability. For example, resin sheets can be suitably used to form insulating layers for circuit boards such as printed wiring boards.

<Circuit board>
The circuit board includes a cured product of a resin composition. Typically, the circuit board includes a cured product layer formed from the cured product of the resin composition, and this cured product layer can function as an insulating layer or a sealing layer. This circuit board can be produced, for example, by a production method including the following steps (1) and (2).
(1) A step of forming a resin composition layer on a substrate.
(2) A step of thermally curing the resin composition layer to form a cured product layer.

In step (1), a substrate is prepared. Examples of substrates include glass epoxy substrates, metal substrates (stainless steel, cold-rolled steel sheet (SPCC), silicon wafers, etc.), polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may also have a metal layer, such as copper foil, on its surface. For example, a substrate having a peelable first metal layer and a peelable second metal layer on both surfaces may be used. When using such a substrate, a conductor layer, which functions as a wiring layer capable of functioning as circuit wiring, is typically formed on the surface of the second metal layer opposite the first metal layer. Examples of materials for the metal layer include copper foil, copper foil with a carrier, and the conductor layer materials described below. Copper foil is preferred. An example of a substrate with a metal layer is "Micro Thin," an ultra-thin copper foil with a carrier manufactured by Mitsui Mining & Smelting Co., Ltd.

A conductor layer may also be formed on one or both surfaces of the substrate. In the following description, a component including a substrate and a conductor layer formed on the substrate surface may be referred to as a "substrate with wiring layer" where appropriate. Examples of conductor materials included in the conductor layer include materials containing one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor material may be a single metal or an alloy. Examples of alloys include alloys of two or more metals selected from the above group (e.g., nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys). Among these, from the viewpoints of versatility, cost, and ease of patterning in conductor layer formation, single metals such as chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper are preferred; and alloys such as nickel-chromium alloys, copper-nickel alloys, and copper-titanium alloys are preferred. Among these, the single metals chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, and copper; and nickel-chromium alloys; are more preferred, with the single metal copper being particularly preferred.

The conductor layer may be patterned, for example, to function as a wiring layer. In this case, the line (circuit width)/space (width between circuits) ratio of the conductor layer is not particularly limited, but is preferably 20/20 μm or less (i.e., a pitch of 40 μm or less), more preferably 10/10 μm or less, even more preferably 5/5 μm or less, even more preferably 1/1 μm or less, and particularly preferably 0.5/0.5 μm or more. The pitch does not need to be uniform throughout the conductor layer. The minimum pitch of the conductor layer may be, for example, 40 μm or less, 36 μm or less, or 30 μm or less.

The thickness of the conductor layer depends on the substrate design, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, even more preferably 10 μm to 20 μm, and especially preferably 15 μm to 20 μm.

After preparing the substrate, a resin composition layer is formed on the substrate. If a conductor layer is formed on the surface of the substrate, the resin composition layer is preferably formed so that the conductor layer is embedded in the resin composition layer.

The resin composition layer can be formed, for example, by compression molding. In compression molding, a substrate onto which the resin composition has been dispensed using a syringe is placed in a mold, and pressure and, if necessary, heat are applied to the resin composition within the mold to form a resin composition layer on the substrate.

Specific procedures for compression molding can be carried out, for example, as follows: An upper mold and a lower mold are prepared as molds for compression molding. A resin composition is dispensed onto a substrate using a syringe. The substrate onto which the resin composition has been dispensed is attached to the lower mold. The upper and lower molds are then clamped together, and heat and pressure are applied to the resin composition to perform compression molding.

Molding conditions vary depending on the composition of the resin composition, and appropriate conditions can be adopted to achieve good sealing. For example, the mold temperature during molding is preferably 70°C or higher, more preferably 80°C or higher, and particularly preferably 90°C or higher, and preferably 200°C or lower, more preferably 170°C or lower, and particularly preferably 150°C or lower. The pressure applied during molding is preferably 1 MPa or higher, more preferably 3 MPa or higher, and particularly preferably 5 MPa or higher, and preferably 50 MPa or lower, more preferably 30 MPa or lower, and particularly preferably 20 MPa or lower. The cure time is preferably 1 minute or longer, more preferably 2 minutes or longer, and particularly preferably 3 minutes or longer, and preferably 60 minutes or lower, more preferably 30 minutes or lower, and particularly preferably 20 minutes or lower. Typically, the mold is removed after the resin composition layer is formed. The mold may be removed before or after the resin composition layer is thermally cured.

The resin composition layer may also be formed by laminating a resin sheet and a substrate, for example. This lamination can be performed, for example, by thermocompression bonding the resin sheet to the substrate from the support side, thereby laminating the resin composition layer to the substrate. Examples of a member for thermocompression bonding the resin sheet to the substrate (hereinafter sometimes referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll). Note that rather than pressing the thermocompression bonding member directly onto the resin sheet, it is preferable to press it through an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently conform to the surface irregularities of the substrate.

Lamination of the substrate and the resin sheet may be carried out, for example, by vacuum lamination. In vacuum lamination, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C. The thermocompression pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa. The thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 13 hPa or less.

After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing process may be the same as the thermocompression conditions for lamination described above. Note that lamination and smoothing may be performed consecutively using a vacuum laminator.

After forming a resin composition layer on the substrate, the resin composition layer is thermally cured to form a cured product layer. The thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but the curing temperature is typically in the range of 120°C to 240°C (preferably 150°C to 220°C, more preferably 170°C to 200°C), and the curing time is in the range of 5 to 120 minutes (preferably 10 to 100 minutes, more preferably 15 to 90 minutes).

Before thermally curing the resin composition layer, the resin composition layer may be subjected to a preheating treatment in which the resin composition layer is heated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature typically between 50°C and 120°C (preferably between 60°C and 110°C, and more preferably between 70°C and 100°C) for typically 5 minutes or more (preferably between 5 and 150 minutes, and more preferably between 15 and 120 minutes).

In this manner, a circuit board having a cured layer formed from a cured product of the resin composition can be produced. The method for producing a circuit board may further include any optional step.
For example, when a circuit board is manufactured using a resin sheet, the manufacturing method of the circuit board may include a step of peeling off the support of the resin sheet. The support may be peeled off before or after the resin composition layer is thermally cured.

The method for manufacturing a circuit board may include, for example, a step of polishing the surface of the cured material layer after forming the cured material layer. The polishing method is not particularly limited. Examples of polishing methods include chemical mechanical polishing using a chemical mechanical polishing device, mechanical polishing using a buff, and surface grinding using a rotating grinding wheel.

The method for manufacturing a circuit board may include, for example, step (3) of connecting the conductor layers to each other, such as drilling holes in the cured material layer. This allows holes such as via holes and through holes to be formed in the cured material layer. Methods for forming via holes include, for example, laser irradiation, etching, and mechanical drilling. The dimensions and shape of the via holes may be determined appropriately depending on the final design of the circuit board. Note that step (3) may also involve polishing or grinding the cured material layer to achieve interlayer connection.

After the via holes are formed, it is preferable to perform a step of removing smears from within the via holes. This step is sometimes called a desmear step. For example, if a conductor layer is formed on the cured material layer by a plating step, the via holes may be subjected to a wet desmear treatment. Furthermore, if a conductor layer is formed on the cured material layer by a sputtering step, a dry desmear step such as a plasma treatment step may be performed. Furthermore, the cured material layer may be subjected to a roughening treatment in the desmear step.

Also, before forming a conductor layer on the cured material layer, the cured material layer may be subjected to a roughening treatment. This roughening treatment typically roughens the surface of the cured material layer, including the inside of the via holes. The roughening treatment may be either dry or wet. An example of a dry roughening treatment is plasma treatment. An example of a wet roughening treatment is a method in which a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid are performed in this order.

After the via holes are formed, a conductor layer may be formed on the cured material layer. By forming a conductor layer at the location where the via holes are formed, the newly formed conductor layer becomes conductive with the conductor layer on the surface of the substrate, resulting in an interlayer connection. Methods for forming the conductor layer include, for example, plating, sputtering, and vapor deposition. For example, a conductor layer having the desired wiring pattern may be formed by plating the surface of the cured material layer using an appropriate method such as a semi-additive method or a full-additive method. Furthermore, for example, when the support of the resin sheet is a metal foil, a conductor layer having the desired wiring pattern may be formed using a subtractive method. The material of the conductor layer formed may be a single metal or an alloy. Furthermore, this conductor layer may have a single-layer structure, or a multi-layer structure containing two or more layers of different materials.

Here, an example of an embodiment in which a conductor layer is formed on a cured material layer will be described in detail. A mask layer is formed on the surface of the cured material layer, and openings are formed in parts of this mask layer as a mask pattern. A metal layer is then formed by sputtering, and the mask layer is then removed. This allows the formation of a conductor layer with the desired wiring pattern. The mask layer is typically formed from a layer of a photosensitive resin composition. The openings in the mask layer can also be formed by exposing and developing the layer of the photosensitive resin composition.

The method for manufacturing a circuit board may include step (4) of removing the substrate. By removing the substrate, a circuit board having a cured material layer and a conductor layer embedded in this cured material layer is obtained. This step (4) can be performed, for example, when using a substrate having a peelable metal layer.

<Semiconductor chip package>
The semiconductor chip package includes a cured product of the resin composition. Examples of this semiconductor chip package include the following.

The semiconductor chip package according to the first example includes the circuit board described above and a semiconductor chip mounted on the circuit board. This semiconductor chip package can be manufactured by bonding the semiconductor chip to the circuit board.

The bonding conditions for the circuit board and semiconductor chip can be any conditions that allow for conductive connection between the terminal electrodes of the semiconductor chip and the circuit wiring of the circuit board. For example, the conditions used for flip-chip mounting of semiconductor chips can be used. Furthermore, for example, the semiconductor chip and circuit board can be bonded via an insulating adhesive.

An example of a bonding method is to press a semiconductor chip onto a circuit board. The pressing conditions are typically a temperature range of 120°C to 240°C (preferably 130°C to 200°C, more preferably 140°C to 180°C), and a time range of 1 second to 60 seconds (preferably 5 seconds to 30 seconds).

Another example of a bonding method is to bond a semiconductor chip to a circuit board by reflow soldering. Reflow conditions may be in the range of 120°C to 300°C.

After bonding the semiconductor chip to the circuit board, the semiconductor chip may be filled with a mold underfill material. The resin composition described above may be used as this mold underfill material.

The semiconductor chip package according to the second example includes a semiconductor chip and a cured resin composition that encapsulates the semiconductor chip. In such a semiconductor chip package, the cured resin composition typically functions as an encapsulation layer. An example of a semiconductor chip package according to the second example is a fan-out WLP.

The method for manufacturing such a semiconductor chip package includes:
(A) a step of laminating a temporary fixing film on a substrate;
(B) a step of temporarily fixing a semiconductor chip on a temporary fixing film;
(C) forming an encapsulation layer on the semiconductor chip;
(D) peeling the substrate and the temporary fixing film from the semiconductor chip;
(E) forming a rewiring formation layer on the surface of the semiconductor chip from which the substrate and the temporary fixing film have been peeled off;
(F) forming a rewiring layer as a conductor layer on the rewiring formation layer; and
(G) forming a solder resist layer on the rewiring layer;
The method for manufacturing the semiconductor chip package also includes:
(H) dicing the plurality of semiconductor chip packages into individual semiconductor chip packages.

(Process (A))
Step (A) is a step of laminating a temporary fixing film on a substrate. The lamination conditions for the substrate and the temporary fixing film can be the same as the lamination conditions for the substrate and the resin sheet in the method for producing a circuit board.

Examples of substrates include silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC); substrates such as FR-4 substrates made of glass fibers impregnated with epoxy resin or the like and then heat-cured; and substrates made of bismaleimide triazine resins such as BT resin.

The temporary fixing film can be made of any material that can be peeled off from the semiconductor chip and temporarily fix the semiconductor chip. Commercially available products include "Riva Alpha" manufactured by Nitto Denko Corporation.

(Process (B))
Step (B) is a step of temporarily fixing semiconductor chips on a temporary fixing film. Temporarily fixing semiconductor chips can be performed using, for example, a device such as a flip chip bonder or a die bonder. The layout and number of semiconductor chips to be arranged can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor chip packages to be produced, and the like. For example, the semiconductor chips may be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

(Step (C))
Step (C) is a step of forming an encapsulating layer on the semiconductor chip. The encapsulating layer can be formed from a cured product of a resin composition. The encapsulating layer is usually formed by a method including a step of forming a resin composition layer on the semiconductor chip and a step of thermally curing the resin composition layer to form a cured product layer as the encapsulating layer. The formation of the resin composition layer on the semiconductor chip can be carried out by the same method as the method of forming a resin composition layer on a substrate described above in <Circuit Board>, except that a semiconductor chip is used instead of the substrate.

After forming a resin composition layer on the semiconductor chip, the resin composition layer is thermally cured to obtain an encapsulating layer that covers the semiconductor chip. This encapsulates the semiconductor chip with the cured resin composition. The thermal curing conditions for the resin composition layer may be the same as the thermal curing conditions for the resin composition layer in the circuit board manufacturing method. Furthermore, before thermally curing the resin composition layer, the resin composition layer may be subjected to a preheating treatment in which it is heated at a temperature lower than the curing temperature. The processing conditions for this preheating treatment may be the same as the preheating conditions for the circuit board manufacturing method.

(Step (D))
Step (D) is a step of peeling the substrate and the temporary fixing film from the semiconductor chip. It is desirable to adopt an appropriate peeling method depending on the material of the temporary fixing film. Examples of the peeling method include a method in which the temporary fixing film is heated, foamed, or expanded to peel it off. Another example of the peeling method is a method in which the temporary fixing film is irradiated with ultraviolet light through the substrate to reduce the adhesive strength of the temporary fixing film, thereby peeling it off.

In the method of peeling off the temporary fixation film by heating, foaming or expanding it, the heating conditions are usually 100° C. to 250° C. for 1 second to 90 seconds or 5 minutes to 15 minutes. In the method of peeling off the temporary fixation film by reducing the adhesive strength of the temporary fixation film by irradiating it with ultraviolet light, the irradiation dose of ultraviolet light is usually 10 mJ/cm ² to 1000 mJ/cm ² .

When the substrate and temporary fixing film are peeled off from the semiconductor chip as described above, the surface of the encapsulating layer is exposed. The method for manufacturing a semiconductor chip package may include polishing this exposed surface of the encapsulating layer. Polishing can improve the smoothness of the surface of the encapsulating layer. The polishing method can be the same as that described in the method for manufacturing a circuit board.

(Step (E))
In step (E), a rewiring formation layer is formed as an insulating layer on the surface of the semiconductor chip from which the substrate and the temporary fixing film have been peeled off. Usually, this rewiring formation layer is formed on the semiconductor chip and the sealing layer.

Any insulating material can be used for the rewiring formation layer. If the sealing layer is formed from a cured resin composition, the rewiring formation layer formed on this sealing layer is preferably formed from a photosensitive resin composition.

After forming the redistribution layer, via holes are typically formed in the redistribution layer to connect the semiconductor chip and the redistribution layer to each other. When the redistribution layer is made of a photosensitive resin, the method of forming the via holes typically involves exposing the surface of the redistribution layer to light through a mask. Examples of active energy rays include ultraviolet light, visible light, electron beams, and X-rays, with ultraviolet light being particularly preferred. Examples of exposure methods include contact exposure, in which a mask is placed in close contact with the redistribution layer, and non-contact exposure, in which parallel light is used for exposure without placing a mask in close contact with the redistribution layer.

The exposure described above can form a latent image in the redistribution layer, which can then be developed to remove a portion of the redistribution layer and form a via hole as an opening that penetrates the redistribution layer. Development can be performed using either wet or dry development. Examples of development methods include dipping, puddling, spraying, brushing, and scraping, with the puddling method being preferred from the standpoint of resolution.

The shape of the via hole is not particularly limited, but is generally circular (approximately circular). The top diameter of the via hole is preferably 50 μm or less, more preferably 30 μm or less, even more preferably 20 μm or less, and particularly preferably 10 μm or less. Here, the top diameter of the via hole refers to the diameter of the opening of the via hole at the surface of the rewiring formation layer.

(Process (F))
Step (F) is a step of forming a rewiring layer as a conductor layer on the rewiring formation layer. The method of forming the rewiring layer on the rewiring formation layer may be the same as the method of forming a conductor layer on a cured material layer in the method for producing a circuit board. Steps (E) and (F) may be repeated to alternately stack (build up) the rewiring layers and the rewiring formation layers.

(Process (G))
Step (G) is a step of forming a solder resist layer on the rewiring layer. The solder resist layer may be made of any insulating material. Among these, photosensitive resins and thermosetting resins are preferred from the viewpoint of ease of manufacturing a semiconductor chip package. Furthermore, a resin composition may be used as the thermosetting resin.

In addition, in step (G), bumping processing may be performed to form bumps, if necessary. Bumping processing can be performed using methods such as solder balls or solder plating. In addition, via holes can be formed in the bumping processing in the same manner as in step (E).

(Step (H))
The method for manufacturing a semiconductor chip package may include a step (H) in addition to the steps (A) to (G). The step (H) is a step of dicing a plurality of semiconductor chip packages into individual semiconductor chip packages. The method for dicing the semiconductor chip packages into individual semiconductor chip packages is not particularly limited.

<Semiconductor Device>
The semiconductor device includes a semiconductor chip package, and examples of the semiconductor device include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, smartphones, tablet devices, wearable devices, digital cameras, medical equipment, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

The present invention will be explained in more detail below using examples. The present invention is not limited to these examples. In the following, "parts" and "%" used to express amounts refer to "parts by mass" and "% by mass," respectively, unless otherwise specified. Unless otherwise specified, the temperature and pressure conditions are room temperature (25°C) and atmospheric pressure (1 atm), respectively.

<Examples 1 to 9 and Comparative Examples 1 to 4>
Resin compositions were prepared by mixing the components in the amounts shown in Table 1 below. Details of the components shown in Table 1 are as follows.

(A-1) Epoxy resin:
CELLOXIDE 2021P: alicyclic epoxy resin having an ester skeleton ("CELLOXIDE 2021P" manufactured by Daicel Corporation, liquid epoxy resin, epoxy equivalent 126 g/eq.)
HP4032D: naphthalene-type epoxy resin ("HP4032D" manufactured by DIC Corporation, liquid epoxy resin, epoxy equivalent 151 g/eq.)
EX-991L: alkyleneoxy skeleton-containing epoxy resin ("EX-991L" manufactured by Nagase ChemteX Corporation, liquid epoxy resin, epoxy equivalent 450 g/eq.)
EG-280: fluorene structure-containing epoxy resin ("EG-280" manufactured by Osaka Gas Chemicals Co., Ltd., liquid epoxy resin, epoxy equivalent 460 g/eq.)
YX7400: Polyalkyleneoxy structure-containing resin ("YX7400" manufactured by Mitsubishi Chemical Corporation, liquid epoxy resin, epoxy equivalent 440 g/eq)
EP-3950L: Glycidylamine epoxy resin ("EP-3950L" manufactured by ADEKA Corporation, liquid epoxy resin, epoxy equivalent 95 g/eq.)
EP-3980S: Glycidylamine epoxy resin ("EP-3980S" manufactured by ADEKA Corporation, liquid epoxy resin, epoxy equivalent 115 g/eq.)
EP-4088S: Dicyclopentadiene type epoxy resin ("EP-4088S" manufactured by ADEKA Corporation, liquid epoxy resin, epoxy equivalent 170 g/eq.)
ZX1059: A 1:1 (mass ratio) mixture of bisphenol A epoxy resin and bisphenol F epoxy resin ("ZX1059" manufactured by Nippon Steel Chemical & Materials Co., Ltd., liquid epoxy resin, epoxy equivalent 169 g/eq.)
JP-100: Epoxy resin having a butadiene structure ("JP-100" manufactured by Nippon Soda Co., Ltd., liquid epoxy resin, epoxy equivalent 210 g/eq.)

(A-2) Epoxy curing agent:
2,2-Diallylbisphenol A: phenolic curing agent (manufactured by Sigma-Aldrich, active group (phenolic hydroxyl group) equivalent: 154 g/eq.)
Kayahard AA: Amine-based curing agent (4,4'-diamino-3,3'-diethyldiphenylmethane, "Kayahard AA" manufactured by Nippon Kayaku Co., Ltd., active group (amino group) equivalent: 64 g/eq.)
MH-700: Acid anhydride curing agent ("MH-700" manufactured by New Japan Chemical Co., Ltd., active group (acid anhydride group) equivalent: 164 g/eq. (calculated as 2 equivalents of active groups per equivalent of acid anhydride group (-COOCO-))

(B) Inorganic filler:
Silica A: Silica particles (50% cumulative diameter D50=1.5 μm, D90=3.5 μm, specific surface area 2.78 m ² /g, surface treated with KBM573 (manufactured by Shin-Etsu Chemical Co., Ltd.))
Silica B: Silica particles (50% cumulative diameter D50=4 μm, D90=12 μm, specific surface area 3.01 m ² /g, surface treated with KBM573 (manufactured by Shin-Etsu Chemical Co., Ltd.))

(C) Silane coupling agent:
KBM-803: ("KBM803" manufactured by Shin-Etsu Chemical Co., Ltd., 3-mercaptopropyltrimethoxysilane)
KBM-403: ("KBM403" manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane)

(D) Curing accelerator:
2E4MZ: Imidazole curing accelerator ("2E4MZ" manufactured by Shikoku Chemicals Corporation)
2MA-OK-PW: Imidazole-based curing accelerator ("2MA-OK-PW" manufactured by Shikoku Chemicals Co., Ltd.)

(E) Radical polymerizable compound:
M-130G: a compound having a methacryloyl group and a polyethylene oxide structure ("M-130G" manufactured by Shin-Nakamura Chemical Co., Ltd., methacryloyl group equivalent: 628 g/eq.)
M-230G: a compound having a methacryloyl group and a polyethylene oxide structure ("M-230G" manufactured by Shin-Nakamura Chemical Co., Ltd., methacryloyl group equivalent: 1068 g/eq.)

(F) Radical polymerization initiator:
Perhexyl O: Radical polymerization initiator (NOF Corporation, "Perhexyl (registered trademark) O")

(G) Polyether skeleton-containing compound:
Polyether polyol A: A resin synthesized as follows. 22.6 g of ε-caprolactone monomer (Daicel Corporation's "Placcel M"), 10 g of polypropylene glycol, diol type, 3,000 (Fujifilm Wako Pure Chemical Industries, Ltd.), and 1.62 g of tin(II) 2-ethylhexanoate (Fujifilm Wako Pure Chemical Industries, Ltd.) were charged into a reaction vessel, heated to 130°C under a nitrogen atmosphere, and stirred for approximately 16 hours to react. The reaction product was dissolved in chloroform, reprecipitated with methanol, and then dried to obtain a polyester polyol resin A having an aliphatic skeleton and terminated with hydroxyl groups. GPC analysis revealed Mn = 9000.
L-64: Polyoxyethylene polyoxypropylene glycol ("L-64" manufactured by ADEKA Corporation)
KF-6012: Polyoxyalkylene-modified silicone resin ("KF-6012" manufactured by Shin-Etsu Chemical Co., Ltd., viscosity (25°C): 1500 mm ² /s)

<Test Example 1: Viscosity Measurement>
The viscosity of the resin compositions obtained in the examples and comparative examples was measured using an E-type viscometer RE-80U (manufactured by Toki Sangyo Co., Ltd.) with a cone rotor of 3° x R9.7, calibrated with the viscosity calibration standard liquid JS52000, at a temperature of 25°C and a rotation speed of 1 rpm.

Test Example 2: Evaluation of dispensability, ejection workability, and resin flowability
A 12 oz syringe (Saneitec Co., Ltd. 5194C, end cap A605, tip cap 5192RT, plunger 5196PRS, syringe outlet inner diameter 14.22 mm, outer diameter 19.30 mm, opening inner diameter 40.26 mm, length from outlet to opening 311.40 mm) filled with 200 g of the resin composition (room temperature (23°C)) obtained in the Examples or Comparative Examples was prepared, and a nozzle (tube material The syringe was made of silicone, the material of the syringe connection part was polypropylene, the total length of the tube part was 52 mm, the length of the part exposed from the syringe connection part of the tube part was 25 mm, the total length of the syringe connection part was 52 mm, the nozzle discharge part (tube part side) outer diameter 12 mm, inner diameter 9 mm, nozzle opening (syringe connection part side) outer diameter 14.22 mm) was attached, and the syringe was attached to a dispenser (Apic Yamada Co., Ltd. "Liquid Manual Dispenser"). The height from the surface of a horizontally placed 12-inch silicon wafer (Ra 10 Å or less) to the nozzle discharge outlet (distance perpendicular to the surface of the silicon wafer) was set to 3 cm, and 40 g ± 1.5 g of the resin composition was dispensed from the nozzle discharge outlet onto the 12-inch silicon wafer at room temperature (23 ° C) at a rate of 2 g / sec. Dispensing was stopped when 40 g ± 1.5 g was dispensed, forming a resin dome of the resin composition.

Evaluation of dispensability: If backflow, in which the resin composition leaked from the side of the plunger during dispensing, occurred, it was marked "X", and if it did not occur, it was marked "O".

Evaluation of dispensing workability: If poor liquid separation between the resin composition and the nozzle outlet caused the dispensed resin composition to remain connected to the nozzle outlet when dispensing stopped, or if resin dripped from the nozzle outlet after dispensing was completed, the evaluation was marked "X." If neither of these occurred, the evaluation was marked "O."

Evaluation of resin flow: After dispensing, the resin was molded in a compression molding device at 120°C and 6 MPa. If the mold was completed without any unfilled areas, it was marked as "Good." If the resin leaked from the mold and soiled the device, it was marked as "Poor."

<Test Example 3: Calculation of H ₂ /H ₁ value and L ₁ /L ₂ value>
A 12 oz syringe (Saneitec Co., Ltd. 5194C, end cap A605, tip cap 5192RT, plunger 5196PRS, syringe outlet inner diameter 14.22 mm, outer diameter 19.30 mm, opening inner diameter 40.26 mm, length from outlet to opening 311.40 mm) filled with 200 g of the resin composition (room temperature (23°C)) obtained in the Examples or Comparative Examples was prepared, and the syringe was attached to a dispenser (Apic Yamada Co., Ltd. "Liquid Manual Dispenser") without a nozzle attached to the syringe. The height from the surface of a horizontally placed 12-inch silicon wafer (Ra 10 Å or less) to the syringe outlet (the distance perpendicular to the surface of the silicon wafer) was set to 5 cm, and 40 g±1.5 g of the resin composition was dispensed from the syringe outlet onto the 12-inch silicon wafer at a rate of 2 g/sec at room temperature (23°C). Dispensing was stopped when 40 g±1.5 g had been dispensed, forming a resin dome of the resin composition. In Comparative Example 3, the outlet and the resin dome were in contact when dispensing was stopped, so after dispensing was stopped, the outlet was pulled up to separate it from the resin dome.

After the resin dome was formed, the change in shape of the resin dome was observed at room temperature (23°C), and the height _H1 from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing, the diameter _L1 of the contact surface of the resin dome with the silicon wafer, the height _H2 from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing, and the diameter _L2 of the contact surface of the resin dome with the silicon wafer were measured, and the _H2 / _H1 value and the _L1 / _L2 value were calculated, and the cases where the following formulas (1) and (2) were satisfied were evaluated as "Good", and the cases where they were not satisfied were evaluated as "Poor".

In the examples and comparative examples other than Comparative Example 3, the point at which 40 g±1.5 g of resin composition had been dispensed was taken as the point at which dispensing was completed, and in Comparative Example 3, the point at which the discharge outlet separated from the resin dome after the operation of pulling the discharge outlet away from the resin dome was taken as the point at which dispensing was completed.
0.15<H ₂ /H ₁ <0.90 (1)
0.40<L ₁ /L ₂ <0.96 (2)

The non-volatile component contents of the resin compositions of the Examples and Comparative Examples, as well as the measurement results and evaluation results of the test examples, are shown in Table 1 below.

As shown in Table 1, when condition (1) is met, dispensability, ejection workability, and resin flowability are good.

REFERENCE SIGNS LIST 10 Syringe filled with resin composition 11 Syringe 12 Resin composition 13 Plunger 14 Female thread portion 15 Discharge port 16 Opening 17 Tip cap 18 End cap 20 Nozzle 21 Tube portion 22 Syringe connecting portion 23 Nozzle discharge portion 24 Nozzle opening 25 Male thread portion 30 Resin dome 40 Silicon wafer

Claims (20)

A resin composition-filled syringe comprising a syringe and a resin composition filled in the syringe,
the resin composition comprises (A-1) an epoxy resin and (B) an inorganic filler, the 90% cumulative diameter D90 of component (B) is 30 μm or less, and the difference between the 90% cumulative diameter D90 and the 50% cumulative diameter D50 (D90−D50) is 20 μm or less;
When the nonvolatile components in the resin composition are taken as 100% by mass, the content of the (B) component is 65% by mass or more and 95% by mass or less,
When the total amount of nonvolatile components other than the component (B) in the resin composition is taken as 100% by mass, the content of the component (A-1) is 10% by mass or more and 90% by mass or less;
the content of the (J) organic solvent in the resin composition is 1% by mass or less relative to 100% by mass of all nonvolatile components in the resin composition;
The resin composition
In a resin composition evaluation test in which a resin composition is dispensed onto the surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and changes in the shape of the resin dome are measured,
The height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing is defined as H ₁ ,
When the height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing is _H2 ,
A syringe filled with a resin composition, which satisfies the condition of the following formula (1):
0.15<H ₂ /H ₁ <0.90 (1) The evaluation test
2. The syringe filled with the resin composition according to claim 1, comprising dispensing 40 g±1.5 g of the resin composition at 23°C onto the surface of the silicon wafer at a rate of 2 g/sec under a condition of 23°C from a discharge outlet installed at a position 5 cm above the surface of the silicon wafer, and then stopping the dispensing to form a resin dome of the resin composition. In the evaluation test,
If the discharge port and the resin dome are not in contact with each other when the dispensing of the resin composition is stopped, the time when 40 g±1.5 g of the resin composition has been dispensed is regarded as the dispensing completion time.
3. The syringe filled with a resin composition according to claim 2, wherein if the outlet and the resin dome are in contact when dispensing of the resin composition is stopped, the outlet is pulled up after dispensing is stopped to separate the outlet from the resin dome, and the point at which the outlet separates from the resin dome is considered to be the point at which dispensing is completed. The diameter of the contact surface of the resin dome with the silicon wafer 60 seconds after the completion of dispensing is defined as L ₁ ,
When the diameter of the contact surface of the resin dome with the silicon wafer 180 seconds after the completion of dispensing is _L2 ,
The syringe filled with the resin composition according to any one of claims 1 to 3, further satisfying the condition of the following formula (2):
0.40<L ₁ /L ₂ <0.96 (2) The resin composition-filled syringe according to any one of claims 1 to 4, wherein the viscosity of the resin composition measured using an E-type viscometer at a temperature of 25°C and a rotation speed of 1 rpm is 1,000 Pa·s or less. The resin composition-filled syringe according to any one of claims 1 to 5, wherein the viscosity of the resin composition measured using an E-type viscometer at a temperature of 25°C and a rotation speed of 1 rpm is 100 Pa·s or more and 500 Pa·s or less. In a resin composition evaluation test in which a resin composition is dispensed onto the surface of a horizontally placed silicon wafer to form a resin dome of the resin composition, and changes in the shape of the resin dome are measured,
The height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 60 seconds after the completion of dispensing is defined as H ₁ ,
When the height from the contact surface of the resin dome with the silicon wafer to the apex of the resin dome 180 seconds after the completion of dispensing is _H2 ,
A resin composition that satisfies the condition of the following formula (1):
the resin composition comprises (A-1) an epoxy resin and (B) an inorganic filler, the 90% cumulative diameter D90 of component (B) is 30 μm or less, and the difference between the 90% cumulative diameter D90 and the 50% cumulative diameter D50 (D90−D50) is 20 μm or less;
When the nonvolatile components in the resin composition are taken as 100% by mass, the content of the (B) component is 65% by mass or more and 95% by mass or less,
When the total amount of nonvolatile components other than the component (B) in the resin composition is taken as 100% by mass, the content of the component (A-1) is 10% by mass or more and 90% by mass or less;
A resin composition, wherein the content of (J) organic solvent in the resin composition is 1 mass% or less, based on 100 mass% of all nonvolatile components in the resin composition.
0.15<H ₂ /H ₁ <0.90 (1) The evaluation test
8. The resin composition according to claim 7, comprising dispensing 40 g±1.5 g of the resin composition at 23°C onto the surface of the silicon wafer at a rate of 2 g/sec under a condition of 23°C from a discharge port installed at a position 5 cm above the surface of the silicon wafer, and stopping the dispensing to form a resin dome of the resin composition. In the evaluation test,
If the discharge port and the resin dome are not in contact with each other when the dispensing of the resin composition is stopped, the time when 40 g±1.5 g of the resin composition has been dispensed is regarded as the dispensing completion time.
9. The resin composition according to claim 8, wherein, if the outlet and the resin dome are in contact when dispensing of the resin composition is stopped, the outlet is pulled up after dispensing is stopped to separate the outlet from the resin dome, and the point at which the outlet separates from the resin dome is taken as the point at which dispensing is completed. The diameter of the contact surface of the resin dome with the silicon wafer 60 seconds after the completion of dispensing is defined as L ₁ ,
When the diameter of the contact surface of the resin dome with the silicon wafer 180 seconds after the completion of dispensing is _L2 ,
The resin composition according to any one of claims 7 to 9, further satisfying the condition of the following formula (2):
0.40<L ₁ /L ₂ <0.96 (2) The resin composition according to any one of claims 7 to 10, wherein the viscosity of the resin composition measured using an E-type viscometer at a temperature of 25°C and a rotation speed of 1 rpm is 1,000 Pa·s or less. The resin composition according to any one of claims 7 to 11, wherein the viscosity of the resin composition measured using an E-type viscometer at a temperature of 25°C and a rotation speed of 1 rpm is 100 Pa·s or more and 500 Pa·s or less. The resin composition described in any one of claims 7 to 12 is used to form an insulating layer for a semiconductor chip package. The resin composition according to any one of claims 7 to 12 for forming an insulating layer of a circuit board. The resin composition according to any one of claims 7 to 12, for encapsulating a semiconductor chip in a semiconductor chip package. A cured product of the resin composition described in any one of claims 7 to 15. A circuit board comprising an insulating layer formed from a cured product of the resin composition according to any one of claims 7 to 12 or 14 . A semiconductor chip package comprising the circuit board according to claim 17 and a semiconductor chip mounted on the circuit board. A semiconductor chip package comprising a semiconductor chip and a cured product of the resin composition according to any one of claims 7 to 12 or 15 that encapsulates the semiconductor chip. A semiconductor device comprising the semiconductor chip package according to claim 18 or 19.