JP6790658B2 - Laminated board for wiring board and wiring board - Google Patents

Description

The present invention relates to a laminated board for a wiring board and a wiring board.

In recent years, electronic devices such as portable information and communication device terminals have been rapidly miniaturized and highly functional, and thin and highly functional semiconductor devices are required. If the wiring board used for the semiconductor device is made thin, it is directly linked to the thinning of the semiconductor device, and the length of the conductor path in the wiring board can be shortened, which is advantageous for high functionality. Therefore, it is required to make the wiring board material as thin as possible. At the same time, by reducing the size of the via holes that connect the conductor layers in the wiring board, more wiring can be routed between the vias, and the number of via holes per unit area can be increased. The density of the electric circuit in the wiring board can be increased. Therefore, an easy method for forming a small diameter via is required.

As a method for forming a small-diameter via, a method of burning off an insulating material using a laser and a method of obtaining an opening by a photolithography process using a photosensitive insulating resin are known (see, for example, Patent Documents 1 and 2). ..

Currently, CO ₂ lasers are most commonly used for the formation (drilling) of via holes. For principle reasons, the hole diameter is limited to about 50 μm, and in order to further reduce the via diameter, it is essential to apply a YAG laser, excimer laser, etc., as described in Patent Document 1. is there. However, these laser devices are much more expensive than CO ₂ laser devices. Further, since the laser cannot open multiple holes at the same time, the tact time at the time of increasing the number of holes may become very long.

On the other hand, via formation using a photosensitive insulating resin does not require expensive equipment because a general photolithography process is applied. Further, since multiple holes can be opened at the same time, the tact time is not affected by the number of holes, and the drilling time can be extremely shortened. However, it is difficult to keep the coefficient of thermal expansion low because the glass cloth cannot be applied to the via formation using the photosensitive insulating resin and the amount of the inorganic filler that can be contained is also limited. Therefore, as described in Patent Document 2, it is necessary to use it in combination with other low thermal expansion materials, and it is difficult to apply it to a thin wiring board.

In addition, in these methods, smear (working waste) is generated inside or near the via, so a desmear (debris removal) process is indispensable. However, as the diameter of the via becomes smaller, desmear using a chemical solution is used. Difficulty increases due to reasons such as liquid circulation. From the above, there is a problem as an easy method for forming a small-diameter via on a thin wiring board.

On the other hand, a drilling method using sandblasting has existed for a long time. A special dry film resist is used to cover the part other than the part to be drilled, and air mixed with abrasive grains is blown to grind the material to make a hole (see, for example, Patent Document 3). The equipment is cheaper than YAG lasers, etc., the tact time does not depend on the number of holes, and glass cloth can be processed, so low thermal expansion materials can be applied, and smear does not easily accumulate in holes due to the processing principle. Many problems of the method using a laser or a photosensitive insulating resin can be solved. In recent years, advances in blasting devices have made it possible to open vias with relatively small diameters.

Japanese Unexamined Patent Publication No. 2004-235202 Japanese Unexamined Patent Publication No. 2014-225671 Japanese Unexamined Patent Publication No. 2004-160649

However, there are not many achievements in processing thin wiring boards using the sandblasting method, and it has not been clarified what kind of wiring board material is most suitable for sandblasting. Therefore, as a result of diligent studies by the present inventors, it is important to increase the processing speed of the wiring board material (laminated board) because the dry film resist has to be thinned in order to process the small diameter via by sandblasting. I found that. At the same time, it was found that it is important to ensure good handleability because the wiring board is extremely thin.

Therefore, the present invention provides a laminated board for a wiring board, which has improved processing speed and good handleability when applied to the manufacture of a thin wiring board using the sandblasting method, and a wiring board using the same. The purpose is.

The present invention has been made in view of such a situation, and as a result of diligent studies, the present inventors have found a laminated board for a wiring board capable of solving all the above problems, and have completed the present invention.

That is, the present invention is characterized by having the following aspects.
[1] A laminated board for a wiring board having a fracture energy per unit volume of 0.001 to 0.01 J / mm ³ and an elastic modulus of 24000 MPa or more.
[2] The laminated board for a wiring board according to [1], which has a thickness of 20 to 100 μm.
[3] A wiring board formed by forming wiring on the laminated board for the wiring board according to [1] or [2].

According to the present invention, when applied to the production of a thin wiring board using the sandblasting method, a laminated board for a wiring board having improved processing speed and good handleability, and a wiring board using the same are provided. can do.

It is a figure for demonstrating the calculation method of the fracture energy and elastic modulus. It is sectional drawing which shows one Embodiment of the wiring formation method schematically.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. Further, the dimensional ratios in the drawings are not limited to the ratios shown.

In the present specification, the fracture energy and elastic modulus per unit volume can be obtained as follows. First, a laminated plate having a thickness (h) of 0.4 mm is cut into a size having a width (b) of 25 mm and a length of 50 mm with a die or the like to prepare a test piece. The test piece breaks under the conditions of the distance between fulcrums (L) 20 mm, the test speed 1 mm / min, and the temperature 20 to 25 ° C. (Here, after recording the maximum load, when the load drops to 3/4 of the maximum load, " A three-point bending test is performed up to "fracture"), and the bending stress (σ) and bending strain (ε) are calculated from the obtained bending load (F) and bending deflection (s), and the stress-strain curve (S-) is calculated. S curve) is obtained. The formulas for calculating the bending stress (σ) and the bending strain (ε) are σ = (3FL) / (2bh ² ) and ε = (6hs) / L ² . Here, as shown in FIG. 1, the area of the obtained SS curve is defined as the fracture energy per unit volume, and the slope of the rising tangent is defined as the elastic modulus.

It should be noted that the method for producing the laminated board for the wiring board is not particularly specified, and various methods can be adopted. For example, after impregnating or coating a glass cloth with a resin composition for a wiring board, a plurality of prepregs obtained by semi-curing (B-stage) by heating are stacked, and copper foils are arranged on one or both sides thereof. The copper foil layer of the copper foil-clad laminate obtained by laminating and forming by a heat-pressing press may be melted with a copper etching solution. As the glass cloth, E glass, T glass, D glass, or the like having an arbitrary thickness can be preferably used depending on the actual application.

The fracture energy per unit volume of the laminated board for wiring boards of this embodiment is 0.001 to 0.01 J / mm ³ . If the breaking energy is less than 0.001 J / mm ³ , the laminated plate is likely to be cracked or cracked due to various external forces when handling the laminated plate, which is not preferable. Further, if the fracture energy exceeds 0.01 J / m ³ , the laminated plate is less likely to be shattered during sandblasting, and the processing speed is lowered, which is not preferable. The breaking energy is preferably 0.0015 to 0.008 J / mm ³ , and more preferably 0.002 to 0.006 J / mm ³ from the viewpoint of further improving handleability and processing speed.

The elastic modulus of the laminated board for the wiring board of this embodiment is 24000 MPa or more. If the elastic modulus is less than 24,000 MPa, the ultra-thin laminated board tends to bend, which makes it difficult to transport the laminated board and the wiring board and to insert and remove the laminated board from the magazine rack, which is not preferable. This elastic modulus is preferably 27,000 MPa or more, more preferably 30,000 MPa or more, from the viewpoint of suppressing deflection and further improving handleability. The upper limit of the elastic modulus is not particularly limited, but can be, for example, 40,000 MPa or less.

The reason why the laminated board for the wiring board of the present embodiment exerts the above-mentioned effect by satisfying the above-mentioned predetermined requirements is not necessarily clear, but the present inventors speculate as follows.
By setting the fracture energy to a predetermined value or less, it can be efficiently shattered when the abrasive grains of sandblasting collide, and by having a fracture energy of a predetermined value or more, it prevents breakage and cracking when handling the laminated board. be able to. Further, by setting the elastic modulus to a predetermined value or more at the same time, the deflection can be suppressed to be small even if the laminated plate is made extremely thin, and the handleability is excellent.

Here, the resin composition for a wiring board applied to the laminated board for a wiring board is not particularly limited in composition as long as it has the above-mentioned predetermined fracture energy and elastic modulus when the laminated board is manufactured, and various types of resin compositions are used. It can be a composition. For example, an amine compound having at least two primary amino groups in the molecular structure, an amine compound having an acidic substituent, and a maleimide compound having at least two N-substituted maleimide groups in the molecular structure are blended or reacted. The thermosetting resin composition may be obtained by subjecting the mixture to at least one phosphorus-containing compound selected from a phosphonium salt and a phosphine-Lewis acid complex; at least one thermosetting resin selected from an epoxy resin or a cyanate resin. The composition may further contain at least one selected from the group consisting of an inorganic filler; and a thermoplastic elastomer. In particular, when an amine compound having at least two primary amino groups in the molecular structure and a maleimide compound having at least two N-substituted maleimide groups in the molecular structure are contained, a good glass transition temperature (Tg), Computers and information equipment that can process a large amount of data at high speed by obtaining low thermal expansion modulus, elastic modulus, copper foil adhesion, desmear resistance, high density and high multilayer printed wiring board. It can be suitably used for a wiring board of an electronic device used such as a terminal, and is preferable.

The laminated board for a wiring board of this embodiment can be manufactured by, for example, the above-mentioned method or the like. The laminated plate may be a copper foil-clad laminate having copper foil on one side or both sides, but the breaking energy and elastic modulus are the breaking energy and elastic modulus of the laminated plate in the portion excluding the copper foil. The thickness of the laminated board (thickness excluding copper for the copper foil-clad laminated board) is preferably 20 to 100 μm. If this thickness is less than 20 μm, the deflection tends to be too large and it tends to be difficult to handle the laminated board alone. Further, if it exceeds 100 μm, it tends to be difficult for a via having a small diameter to open. This thickness is more preferably 25 to 80 μm, still more preferably 30 to 60 μm, from the viewpoint of suppressing deflection and improving handleability.

The laminated board for a wiring board of the present embodiment can be suitably used as a build-up layer in the wiring board. A conventionally known method can be adopted as a method for forming the wiring on the laminated board for the wiring board, and for example, the wiring can be formed by the method shown in FIG.

First, as shown in FIG. 2A, a laminate 3 including a support base material 1 and a conductor layer 2 formed on the support base material 1 is prepared (preparation step). The laminate 3 is obtained, for example, by laminating a conductor on the support base material 1.

The support base material 1 includes, for example, a substrate 4 and a plurality of metal foil layers 5a and 5b formed on the substrate 4. The substrate 4 may be FR-4 (glass epoxy resin base material), FR-5 (heat resistant glass epoxy base material), SUS (stainless steel) base material, or the like. The metal foil layer 5 may be composed of two or more metal foil layers, and at least two layers of the plurality of metal foil layers can be physically separated from each other. The metal foil layer 5 is preferably formed of a peelable copper foil. Since the thickness of the layer farthest from the substrate 4 of the peelable copper foil layer is extremely thin, the time can be shortened at the time of final etching out. The support base material 1 is preferably one in which a peelable copper foil is attached to FR-4 or FR-5, but a metal foil layer may be formed on a SUS plate by a plating treatment.

The conductor layer 2 is made of, for example, copper. The conductor layer 2 may be, for example, a wiring patterned on the support base material 1, or may be a pad, a dummy pattern, or the like. The method for forming the conductor layer 2 is not particularly limited, and may be, for example, a method in which a metal foil layer (peelable copper foil layer) 5 is used as a seed layer and formed by a plating process.

Following the preparation step, as shown in FIG. 2B, the build-up layer 6 is formed on the support base material 1 so as to cover the conductor layer 2 by using the laminated board for the wiring board of the present embodiment. (Build-up layer forming process). The build-up layer 6 is formed, for example, by vacuum-pressing a laminated board for a wiring board on a support base material 1.

Following the build-up layer forming step, as shown in FIG. 2C, a resin layer (primer resin layer for plating process) 7 is formed on the build-up layer 6 (resin layer forming step). The resin layer 7 is formed, for example, by laminating. The resin used for the resin layer 7 is preferably a polyfunctional epoxy resin because it has little effect on the physical properties of the build-up layer 6 and has good adhesion to electroless plating.

Following the resin layer forming step, as shown in FIG. 2C, the first dry film resist layer 8 is formed on the resin layer 7 (first dry film resist layer forming step). The first dry film resist layer 8 can be formed by a known method such as roll laminating or vacuum laminating. Laminating may be performed under the conditions of, for example, 0.001 N or more at 0 to 180 ° C. and a roll speed of 0.01 mm / s or more.

From the viewpoint of achieving both resolution and sandblast resistance, the thickness of the first dry film resist layer 8 is preferably 35 μm or less, and the first dry film resist layer 8 is preferably carboxyl. Alkali-soluble resins containing group-based cellulose or acrylic resins having carboxyl groups, photopolymerizable compounds containing ethylenically unsaturated groups or monofunctional compounds, urethane (meth) acrylate compounds, and photopolymerization initiators. It is formed of a photosensitive resin composition containing.

Following the first dry film resist layer forming step, as shown in FIG. 2D, for example, using an exposure mask 9, a predetermined region that is a part of the first dry film resist layer 8 is exposed to active light L. Exposure with (exposure process). The predetermined region here is a region where an opening is planned to be formed in the first dry film resist layer 8. The exposure method may be a direct drawing method using a UV laser instead of the method using the exposure mask 9.

Following the exposure step, as shown in FIG. 2 (e), the unexposed region of the first dry film resist layer 8 after exposure (the region where the active light L was blocked by the exposure mask 9 in the exposure step). Is removed to form the opening 10 (opening forming step). The opening 10 is formed at a position corresponding to a region where IVH (Inner Via Hole) is to be formed in the build-up layer 6.

The method for removing the unexposed region of the first dry film resist layer 8 is not particularly limited, and examples thereof include a method of removing by shower development or mist development using a developing solution, a method of removing by a sandblast method, and the like. From the viewpoint of simplifying the steps by omitting the shower development or mist development with a developing solution, washing and drying steps, a method of removing by a sandblasting method is preferable. The sandblasting is performed under the same conditions as the sandblasting in the IVH forming step described later, for example.

Following the opening forming step, as shown in FIG. 2 (f), IVH11 is formed in the build-up layer 6 by using the sandblasting method (IVH forming step).

In the IVH forming step, the first dry film resist layer 8 having the opening 10 serves as a mask, and by spraying abrasive grains (abrasive), the build-up layer 6 at the position corresponding to the opening 10 is formed. To cut. The conditions for sandblasting are not particularly limited. Examples of the abrasive grains include fine particles such as glass beads, SiC, SiO ₂ , Al ₂ O ₃ , and ZrO. The average particle size of the abrasive grains may be, for example, 2 to 100 μm. The abrasive grains are preferably Al ₂ O ₃ fine particles (alumina powder) having an average particle size of 30 μm or less. The amount of the abrasive grains injected is preferably such that the abrasive grains do not clog the IVH.

The diameter of IVH11 is 50 μm or less, and is preferably 40 μm or less, more preferably 30 μm or less, because the electric circuit (wiring) in the wiring board can be densified. When the diameter of IVH11 is 50 μm or less, the density of the electric circuit (wiring) in the wiring board is increased, the increase in the number of build-up layers 6 is suppressed, and the IVH is formed by the conventional CO ₂ laser. The cost is low.

After the IVH forming step, for example, the first dry film resist layer 8 remaining on the resin layer 7 without being scraped by sandblasting is removed (first dry film resist layer removing step). Examples of the method for removing the first dry film resist layer 8 include a method for removing the dry film resist layer 8 with an alkaline aqueous solution.

After the first dry film resist layer removing step, a seed layer is formed on the resin layer 7, the inner wall of IVH11, and the conductor layer 2 (seed layer forming step). The seed layer is preferably formed of copper. The seed layer is formed by, for example, electroless copper plating. The thickness of the seed layer is not particularly limited.

After the seed layer forming step, a third dry film resist layer is formed on the seed layer (third dry film resist layer forming step). The third dry film resist layer is formed, for example, by the same material and method as the first dry film resist layer 8. The presence or absence of sandblast resistance of the third dry film resist layer does not matter.

After the third dry film resist layer forming step, a predetermined area of the third dry film resist layer is exposed in the same manner as in the first dry film resist layer 8, and then the third dry film resist layer is not yet exposed. Remove the exposed area.

Subsequently, wiring is formed in IVH11 and on the seed layer on which the third dry film resist layer is not formed (wiring forming step). The wiring is preferably made of copper. The wiring is formed, for example, by electrolytic copper plating.

After the wiring forming step, the third dry film resist layer is removed (third dry film resist layer removing step). The third dry film resist layer can be removed by the same method as the first dry film resist layer 8.

After the third dry film resist layer removing step, the seed layer corresponding to the region where the wiring is not laminated is removed (seed layer removing step). Examples of the method for removing the seed layer include etching treatment.

The build-up layer forming step to the seed layer removing step described above may be repeated to form multiple layers. That is, two or more build-up layers 6 may be formed, and the plurality of build-up layers 6 may be electrically connected by wiring.

Next, the present invention will be described with reference to Examples, but the scope of the present invention is not limited to these Examples. The performance of the laminated board obtained in the following examples was measured and evaluated by the following method.

<Measurement of fracture energy and elastic modulus per unit volume>
A laminated plate having a thickness (h) of 0.4 mm is cut into a size having a width (b) of 25 mm and a length of 50 mm with a die or the like to prepare a test piece. The test piece breaks under the conditions of a fulcrum distance (L) of 20 mm, a test speed of 1 mm / min, and a temperature of 20 to 25 ° C using an Instron 5948 type tester (here, after recording the maximum load, the load is maximum. A three-point bending test is performed until the load drops to 3/4 of the load), and the bending stress (σ) and bending strain (ε) are obtained from the obtained bending load (F) and bending deflection (s). Is calculated to obtain a stress-strain curve (SS curve). The formulas for calculating bending stress (σ) and bending strain (ε) are σ = (3FL) / (2bh2) and ε = (6hs) / L2. Here, as shown in FIG. 1, the area of the obtained SS curve was defined as the fracture energy per unit volume, and the slope of the rising tangent was defined as the elastic modulus.

<Evaluation of workability>
First, a dry film layer for sandblasting having an opening of φ80 μm was formed on the surface of the laminated plate. The process is as follows.
A dry film for sandblasting SB-3050 (manufactured by Hitachi Chemical Co., Ltd.) is roll-laminated on the surface of the laminated plate under the conditions of a temperature of 80 ° C., a pressure of 0.4 MPa, and a speed of 1.0 m / min. Using a parallel exposure machine and a negative mask, UV light is irradiated at 115 mJ / cm ^{2 on} a surface other than the portion where the opening is to be formed. Using a spray developer, develop 100 or more holes of φ80 μm in a dry film at intervals of 300 μm or more with a 1.0 wt% Na ₂ CO ₃ aqueous solution. Irradiation with UV light of 1000 mJ / cm ² accelerates curing.
Next, a hole was drilled in the laminated plate using a sandblasting device. The process is as follows.
A laminated plate on which a dry film layer for sandblasting having an opening is formed is set in a sandblasting apparatus ELP-1TR (manufactured by Elfotec). Alumina # 600 abrasive grains having an average particle size of 20 μm are sprayed from a nozzle having a diameter of φ5 mm at a distance of 100 mm from the substrate surface at an injection pressure of 0.15 MPa. At that time, the abrasive grain supply is set to 3 rpm by the rotation speed of the supply roller, the nozzle reciprocates in a width of 130 mm at a moving speed of 8 m / min, and the laminated plate is carried at a speed of 20 mm / min. After passing through the hole of φ80 μm twice, stop the hole processing, take out the laminated plate, and remove the dry film. The depth of the holes machined in the laminated board was randomly measured by a depth meter for 20 holes, and the average was used as an index of workability. It can be said that the larger this value is, the faster the processing speed is, that is, the higher the processability is.

<Evaluation of handleability>
A stack of 20 laminated plates having a size of 200 mm × 200 mm is prepared beside the transport roller. Move the transfer roller under the conditions of transfer roller diameter 50 mm, transfer roller width 1 mm, roller spacing 50 mm, roller shaft pitch maximum 45 mm, and transfer speed 2.0 mm / s, pick up the laminated plates one by one, and place them on the transfer roller. After transporting 5 m, they were collected one by one and stacked. At that time, the damage (cracking and cracking) of the laminated board and the presence or absence of dropping or being caught from the transport roller were checked and used as an index of handleability. This time, we used the board transfer equipment at the laminated board manufacturing site, but if we have similar transfer rollers, there is no particular designation for the transfer equipment.

(Example 1, Comparative Examples 1 to 3)
<Preparation of varnish>
The components (d), (e), (f), (g) and (x) shown below are mixed in the blending ratio (parts by mass; but only the component (g) is vol%) shown in Table 1 and mixed with the solvent. A varnish having a resin content of 65% by mass was prepared using methyl ethyl ketone.
[(D) Thermosetting resin]
(D-1) Dicyclopentadiene type epoxy resin [manufactured by Nippon Kayaku Co., Ltd .; trade name: XD-1000]
(D-2) Biphenyl aralkyl type epoxy resin [manufactured by Nippon Kayaku Co., Ltd .; trade name: NC-3000H]
[(E) Thermoplastic Elastomer]
(E-1) Tough Tech H1043: Hydrogenated styrene-butadiene copolymer resin [manufactured by Asahi Kasei Corporation, trade name]
[(F) Phosphorus-containing compound]
(F-1) Triphenylphosphine Triphenylborane [manufactured by Hokuko Chemical Industry Co., Ltd .; trade name: TPP-S]
[(G) Inorganic filler]
(G-1) Fused silica (manufactured by Admatex Co., Ltd .: trade name: SC2050-KNK)
[(X) Modified Silicone]
Production Example 1: Compound (x-1)
X-22-161A: 30.4 g and 2,2-bis (4- (4)) in a reaction vessel with a volume of 2 liters capable of heating and cooling equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser. -Maleimide Phenoxy) Phenyl) Propane: 192.0 g, p-Aminophenol: 7.3 g, 3,3'-diethyl-4,4'-diaminodiphenylmethane: 20.3 g and Propylene Glycol Monomethyl Ether: 375.0 g Was reacted at 100 ° C. for 3 hours to obtain a compound (x-1) -containing solution.
Production Example 2: Compound (x-2)
X-22-161B: 26.8 g and 3,3'-diethyl-4,4 in a reaction vessel with a volume of 2 liters that can be heated and cooled with a thermometer, agitator, and a moisture meter with a reflux condenser. '-Diaminodiphenylmethane: 301.0 g, p-aminophenol: 7.2 g, bis (4-maleimidephenyl) methane: 22.4 g and propylene glycol monomethyl ether: 536.3 g are added and reacted at 100 ° C. for 3 hours. To obtain a compound (x-2) -containing solution.
Production Example 3: (x-3)
X-22-161B: 39.5 g and 3,3'-diethyl-4,4 in a reaction vessel with a volume of 2 liters capable of heating and cooling equipped with a thermometer, a stirrer, and a moisture meter with a reflux condenser. '-Diaminodiphenylmethane: 211.7 g, p-aminophenol: 5.0 g, bis (4-maleimidephenyl) methane: 13.7 g and propylene glycol monomethyl ether: 405.0 g are added and reacted at 100 ° C. for 3 hours. To obtain a compound (x-3) -containing solution.
<Materials used in Production Examples 1 to 3>
[(A) Amine compound having at least two primary amino groups in its molecular structure]
(A-1) Both-terminal diamine-modified siloxane [manufactured by Shin-Etsu Chemical Co., Ltd .; trade name: X-22-161A]
(A-2) Both-terminal diamine-modified siloxane [manufactured by Shin-Etsu Chemical Co., Ltd .; trade name: X-22-161B]
(A-3) 3,3'-diethyl-4,4'-diaminodiphenylmethane [manufactured by Nippon Kayaku Co., Ltd .; trade name: KAYAHARD AA]
[(B) Amine compound having an acidic substituent]
p-Aminophenol [manufactured by Kanto Chemical Co., Inc.]
[(C) Maleimide compound having at least two N-substituted maleimide groups]
2,2-Bis (4- (4-maleimide phenoxy) phenyl) propane [manufactured by Daiwa Kasei Kogyo Co., Ltd .; trade name: BMI-4000]

<Manufacturing of laminated board for wiring board>
Next, the varnish was impregnated and coated on an E glass cloth having a thickness of 0.1 mm and dried by heating at 160 ° C. for 10 minutes to obtain a prepreg having a resin content of 48% by mass. Four of these prepregs were stacked, 9 μm electrolytic copper foils were placed one above the other, and pressed at a pressure of 2.5 MPa and a temperature of 240 ° C. for 60 minutes to obtain a copper foil-clad laminate. Then, the upper and lower copper foils were dissolved with a copper etching solution and removed to obtain a laminated plate.

Table 2 shows the results of testing and evaluation of the obtained laminated board. In the embodiment, the fracture energy is both easy to break and the handling is achieved, and the high elastic modulus makes it possible to achieve both good workability and handleability of the thin laminated plate. On the other hand, in the comparative example, the workability is excellent but it cracks during handling, or the deflection is large and it is difficult to transport the machine, or the workability is excellent but the processing speed is slow, which is clearly inferior to the example. There is.

As described above, according to the present invention, it becomes possible to manufacture a wiring board for high-density wiring with high efficiency, which is extremely thin but has little deflection and is excellent in handleability. The wiring board is suitable for a thin and highly functional semiconductor device that can cope with miniaturization and high functionality of electronic devices, and has a very large industrial utility value.

1 ... Supporting base material, 2 ... Conductor layer, 3 ... Laminated body, 4 ... Substrate, 5, 5a, 5b ... Metal foil layer, 6 ... Build-up layer, 7 ... Resin layer, 8 ... First dry film resist layer , 9 ... Exposure mask, 10 ... Opening, 11 ... IVH.

Claims (3)

A laminated board for a wiring board having a fracture energy per unit volume of 0.001 to 0.01 J / mm ³ and an elastic modulus of 24000 MPa or more. The laminated board for a wiring board according to claim 1, which has a thickness of 20 to 100 μm. A wiring board formed by forming wiring on the laminated board for the wiring board according to claim 1 or 2.

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