JP7809997B2 - Method for manufacturing electronic components and laminate for use in manufacturing electronic components - Google Patents

Description

The present invention relates to a method for manufacturing encapsulated electronic components, and also to a laminate used in the method.

Traditionally, semiconductor integrated circuit (IC) packages have come in a variety of package formats, including dual in-line packages (DIPs), small outline packages (SOPs), and quad flat packages (QFPs). However, with the recent trend toward smaller and more highly integrated packages, chip-sized packages (CSPs), in which the IC chip package size is the same as the chip itself, are now being adopted. Furthermore, due to demands for smaller and thinner ICs, the method of connecting the IC and package terminals has shifted from the traditional gold wire method to flip-chip connections, which connect the active surface of the IC to the connection terminals with solder balls or gold bumps.

Meanwhile, quartz crystal devices, such as quartz crystal resonators and SAW filters, apply piezoelectric phenomena to electrical circuits, and are used for various IC synchronization reference signals, clocks, and communication circuit noise filters. Because quartz crystal devices convert electrical signals into physical vibrations and vice versa, the active surfaces of the electronic circuit components must exist in space, necessitating a hollow structure, i.e., a package with an internal space. Traditionally, to protect electronic circuit components from the external environment, electronic circuit components were placed inside embossed multilayer ceramic, connected to the electrodes by wire bonding, and sealed with a metal weld. However, with the miniaturization and thinning of communication devices such as mobile phones, a new method has been proposed: flip-chip bonding the active surface of the electronic circuit component to the package substrate, maintaining the space formed by the electronic circuit component, bumps, and package substrate, and then resin-sealing the internal space. Proposed resin sealing methods for this purpose include a method in which a sheet-like sealing material is used to fill the uneven areas formed by mounting electronic circuit components on a substrate while maintaining the space formed by the electronic circuit components, bumps, and package substrate, and a method in which a sheet-like material is used to conform to the uneven shapes formed by mounting the electronic components, covering and protecting the electronic components (Patent Documents 1 to 3).

On the other hand, the demand for smaller quartz crystal devices continues to grow, and the distance between electronic circuit components is becoming smaller. The distance between electronic circuit components, which was previously around 500 μm to 1 mm, is now less than 300 μm, making it difficult to seal with resin using previously proposed methods.

Specifically, while electronic circuit components are becoming smaller, there is a limit to how much the area of the active surface of the electronic circuit component can be reduced. This means that the distance between electronic circuit components is becoming smaller, and the method of conforming the sheet-like material to the uneven surface described above has the problem that it does not conform sufficiently to the recesses, or the sheet-like material tears, resulting in an insufficient seal.

Furthermore, in recent years, electronic component modules have been proposed that integrate electronic components that were previously manufactured individually and provide functionality. A method has been proposed for manufacturing electronic component modules in which multiple electronic circuit components are arranged on a substrate and these electronic circuit components are collectively covered with a sheet-like material (Patent Document 4).
When the spacing between electronic circuit members mounted in such an electronic component module is uneven, it is difficult to make the portions where the distance between electronic circuit members is small and the portions where the distance between electronic circuit members is large to conform to the uneven shape in the same way; in the portions where the distance between electronic circuit members is small, the portions cannot conform to the recesses sufficiently, and when an attempt is made to make the protrusions conform to the portions where the distance between electronic circuit members is small, the pressing force becomes too strong in the portions where the distance between electronic circuit members is large, causing the sheet-like material to tear and preventing successful sealing.

Patent No. 4053483 Patent No. 4730652 Japanese Patent Application Laid-Open No. 2003-17979 Patent No. 6089567

The object of the present invention is to provide a method for manufacturing electronic components that can eliminate problems that arise in such processing steps, resolve issues such as tearing and insufficient conformance to uneven shapes even when the distances between multiple electronic circuit components mounted on a substrate are uneven, and enable the production of electronic components with a high yield, as well as a laminate for use in such a method.

The present invention, which solves the above-mentioned problems, is as follows.
(1) A method for manufacturing an electronic component having a substrate, a plurality of electronic circuit members mounted on the substrate, and a hardened layer, comprising:
A method for manufacturing an electronic component, comprising the following steps 1 to 4 in this order:

Step 1: A step of arranging a curable sheet, a polyolefin sheet, and a resin sheet in the following order: the substrate, the electronic circuit member, the curable sheet, the polyolefin sheet, and the resin sheet;
The polyolefin sheet has a breaking elongation at 80°C of more than 1000% and less than 3000%,
The resin sheet has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less.

Step 2: Heating and pressurizing the curable sheet to conform to the electronic circuit components and seal them.

Step 3: Peeling and removing the polyolefin sheet and the resin sheet.

Step 4: Curing the curable sheet to convert it into a cured layer.
(2) A laminate used in the manufacture of an electronic component having a substrate, a plurality of electronic circuit members mounted on the substrate, and a cured layer,
A laminate in which a curable sheet, a polyolefin sheet, and a resin sheet are laminated in this order,
The polyolefin sheet has a breaking elongation at 80°C of more than 1000% and less than 3000%,
The resin sheet has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less.

The present invention solves problems such as tearing and insufficient conformance to uneven shapes, even when multiple electronic circuit components are arranged at different distances, improving yield in the processing process and producing highly reliable electronic components.

1A and 1B are explanatory views showing a cross section of an electronic circuit member or an electronic component, illustrating steps 0 and 1 of a manufacturing method according to one embodiment of the present invention. 1 is an explanatory diagram showing a cross section of an electronic circuit member or electronic component, illustrating step 2 of a manufacturing method according to an embodiment of the present invention. FIG. 3 is an explanatory diagram showing a cross section of an electronic circuit member or electronic component, illustrating step 3 of the manufacturing method according to one embodiment of the present invention. FIG. 3 is an explanatory diagram showing a cross section of an electronic circuit member or electronic component, illustrating step 3 of the manufacturing method according to one embodiment of the present invention. FIG. FIG. 2 is an explanatory diagram illustrating step 4 of the manufacturing method according to one embodiment of the present invention, using a cross section of an electronic circuit member or electronic component. FIG. 2 is an explanatory diagram illustrating a cross section of an electronic circuit member or electronic component, illustrating a pattern formation step of a curable sheet in a manufacturing method according to one embodiment of the present invention. 1A to 1C are explanatory views showing a cross section of an electronic circuit member or an electronic component, illustrating a mounting step of an electronic circuit member in a manufacturing method according to one embodiment of the present invention. 1A to 1C are explanatory views showing a cross section of an electronic circuit member or an electronic component, illustrating a sealing step using a curable material in a manufacturing method according to one embodiment of the present invention.

The method for manufacturing an electronic component of the present invention is a method for manufacturing an electronic component having a substrate, multiple electronic circuit components mounted on the substrate, and a hardened layer, and comprises the following steps 1 to 4 in this order.

Step 1: A step of arranging a curable sheet, a polyolefin sheet, and a resin sheet in the following order: the substrate, the electronic circuit member, the curable sheet, the polyolefin sheet, and the resin sheet, wherein the polyolefin sheet has a breaking elongation at 80°C of more than 1000% and less than 3000%, and the resin sheet has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less.

Step 2: Heating and pressurizing the curable sheet to conform to the electronic circuit components and seal them.

Step 3: Peeling and removing the polyolefin sheet and the resin sheet.

Step 4: Curing the curable sheet to convert it into a cured layer.

According to the manufacturing method of the present invention, the inertial deformation of the polyolefin sheet and the resin sheet allows the curable sheet to conform to and cover the uneven shapes of multiple electronic circuit components without breaking.

In addition, prior to step 1, a step (step 0) may be carried out in which a curable sheet, a polyolefin sheet, and a resin sheet are laminated to form a laminate.

Alternatively, between steps 3 and 4, a mask having a desired pattern may be formed on the curable sheet sealed to the electronic circuit component, and the curable sheet may be irradiated with light through this mask to expose the curable sheet in a pattern, after which the unexposed areas may be removed with a developer to form a pattern, or multiple new electronic circuit components may be mounted on the substrate from which the curable sheet has been removed by development.

After step 4, or after pattern formation, multiple new electronic circuit components can be mounted on the substrate from which the curable sheet has been removed, and after step 4 has been performed, the sealing process can be carried out again with a different material (curable material), and the material can be heated to the curing temperature to convert it into a cured layer.

Another aspect of the present invention includes electronic components manufactured using the above manufacturing method.

Furthermore, the laminate of the present invention is a laminate used in the manufacture of a substrate, multiple electronic circuit components mounted on the substrate, and an electronic component having a cured layer, and is a laminate comprising a curable sheet, a polyolefin sheet, and a resin sheet laminated in this order, wherein the polyolefin sheet has a breaking elongation at 80°C of more than 1000% and less than 3000%, and the resin sheet has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less.

The manufacturing method and laminate of the present invention will be described in detail below with reference to the drawings.

<<Production Method of the Present Invention>>
<Laminate manufacturing process (process 0)>
The production method of the present invention may include the following step 0 before step 1.

Step 0: Laminating a curable sheet, a polyolefin sheet, and a resin sheet in this order to form a laminate.

Step 0 is a step in which the curable sheet 4, polyolefin sheet 5, and resin sheet 6 are stacked in this order before step 1 to form laminate 7. The method for producing laminate 7 is not particularly limited, and it may be produced, for example, by separately producing the curable sheet 4, polyolefin sheet 5, and resin sheet 6 and then stacking them. The sheets may be stacked on the mounting member, or they may be stacked in advance and placed on the mounting member.

<Placement process (process 1)>
Step 1 is a step of arranging a curable sheet 4, a polyolefin sheet 5, and a resin sheet 6 in the following order: substrate 1, electronic circuit member 2, curable sheet 4, polyolefin sheet 5, and resin sheet 6.

Here, the polyolefin sheet is a sheet having a breaking elongation at 80°C of more than 1000% and less than 3000%. Furthermore, the resin sheet is a sheet having a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less.

The example shown in Figure 1 shows a case where a laminate in which the curable sheet 4, polyolefin sheet 5, and resin sheet 6 are integrated is used (i.e., it shows an embodiment after step 0), but this is not limited to this case; the curable sheet 4, polyolefin sheet 5, and resin sheet 6 may each be prepared separately. Even in this case, the curable sheet 4, polyolefin sheet 5, and resin sheet 6 are simply not integrated (i.e., not formed into a laminate), and the configuration of each sheet and the procedures and conditions for each step in the manufacturing method for electronic components are the same as for integrated sheets (laminates). Furthermore, when laminating each, the curable sheet 4, polyolefin sheet 5, and resin sheet 6 may all be laminated together, i.e., formed into a laminate by step 0, or just two of them may be laminated.

<Curable sheet>
The curable sheet used in the present invention has sufficient elongation to fill spaces between electronic circuit components and is converted into a cured layer by heat and/or light, that is, it is a sheet made of a resin composition containing a binder polymer and a curable resin, and it is preferable that the curable sheet has excellent heat resistance and reliability in particular.

The composition of the curable sheet 4 is not particularly limited as long as it contains a binder polymer and a curable resin. However, the curable sheet preferably contains a thermosetting resin as both the binder polymer and the curable resin, and more preferably contains two thermosetting resin components. In particular, the content of the thermosetting resin in the curable sheet 4 is preferably 5% by mass or more and 40% by mass or less, based on the entire curable sheet being 100% by mass, in order to improve heat resistance and reliability. Furthermore, the content of the binder polymer in the curable sheet 4 is preferably 30% by mass or more and 85% by mass or less, based on the entire curable sheet being 100% by mass, in order to improve the elongation of the curable sheet and its ability to embed between electronic circuit components.

The binder polymer in the curable sheet is not particularly limited, but examples include acrylonitrile-butadiene copolymer (NBR), acrylonitrile-butadiene-styrene resin (ABS), polybutadiene, styrene-butadiene-ethylene resin (SEBS), acrylic copolymer, polyvinyl butyral, polyamide, polyester, polyimide, polyamideimide, polyurethane, etc. Among these, acrylic copolymer is preferred from the standpoint of heat resistance and reliability of electronic components.

The thermosetting resin in the curable sheet is not particularly limited. However, examples of suitable thermosetting resins for use in the curable sheet 4 include well-known thermosetting resins such as epoxy resin, phenol resin, melamine resin, xylene resin, furan resin, and cyanate ester resin, with epoxy resin and phenol resin being particularly suitable in terms of their insulating properties.

Epoxy resins are not particularly limited as long as they contain two or more epoxy groups per molecule. Examples include diglycidyl ethers of bisphenol A, bisphenol F, bisphenol S, resorcinol, dihydroxynaphthalene, dicyclopentadiene diphenol, etc.; epoxidized phenol novolac (phenol novolac type epoxy resin), epoxidized cresol novolac (cresol novolac type epoxy resin); alicyclic epoxies such as epoxidized trisphenylolmethane, epoxidized tetraphenylolethane, epoxidized metaxylenediamine, and cyclohexane diepoxide. Furthermore, halogenated epoxy resins, particularly brominated epoxy resins, may be used to impart flame retardancy.

As phenolic resins, any of the known phenolic resins, such as novolac-type phenolic resins and resol-type phenolic resins, can be used. Examples include alkyl-substituted phenols such as phenol, cresol, p-t-butylphenol, nonylphenol, and p-phenylphenol; cyclic alkyl-modified phenols such as terpene and dicyclopentadiene; resins containing functional groups containing heteroatoms such as nitro groups, halogen groups, cyano groups, and amino groups; resins with skeletons such as naphthalene and anthracene; and resins made from polyfunctional phenols such as bisphenol A, bisphenol F, bisphenol S, resorcinol, and pyrogallol.

The curable sheet 4 may contain components other than those mentioned above (i.e., components other than the binder polymer and curable resin). Examples include inorganic fillers, curing agents, curing accelerators, polymerization initiators, polymerizable compounds, ion catchers, flame retardants, pigments, silane coupling agents, and thixotropic agents.

Examples of inorganic fillers include crystalline silica powder, fused silica powder, alumina, aluminum hydroxide, silicon nitride, magnesium hydroxide, calcium aluminate hydrate, zirconium oxide, zinc oxide, antimony trioxide, antimony pentoxide, titanium oxide, iron oxide, cobalt oxide, chromium oxide, talc, aluminum, gold, silver, nickel, iron, clay, and mica. Among these, aluminum hydroxide, alumina, and silica are preferred from the viewpoint of dispersibility. Among these, silica, preferably spherical silica powder, and more preferably fused spherical silica, having a 5% weight loss temperature (thermal decomposition temperature) of 350°C or higher as measured by TGA (thermal weight loss measurement), is preferred from the viewpoint of reflow heat resistance.

The curing agents in the curable sheet include 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 2,2',3,3'-tetrachloro-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diamino Examples of curing agents that can be used include aromatic polyamines such as benzophenone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, and 3,4,4'-triaminodiphenyl sulfone; boron trifluoride amine complexes such as boron trifluoride triethylamine complex; dicyandiamide; novolac resins such as phenol novolac and cresol novolac; and bisphenol compounds such as bisphenol A. Among these, phenol-based curing agents are preferred due to their excellent heat resistance. These may be used alone or in combination. The inclusion of a curing agent that undergoes a crosslinking reaction with epoxy groups improves adhesive strength after curing.

When using a curing agent that undergoes a crosslinking reaction with epoxy groups, it is preferable that the ratio H/E, where H is the total number of moles of active hydrogen in the curing agent and E is the total number of moles of epoxy groups in the epoxy resin, be in the range of 0.4 to 1.0.

Examples of curing accelerators include well-known compounds such as boron trifluoride amine complexes such as boron trifluoride triethylamine complex, imidazole compounds such as 2-alkyl-4-methylimidazole, dicyandiamide, triphenylphosphine, tetra-n-butylphosphonium o,o-diethylphosphorodithionate, and sulfonium salt derivatives. These may be used alone or in combination of two or more. The amount of curing accelerator is preferably in the range of 0.3 to 3.0 parts by weight per 100 parts by weight of epoxy resin.

Polymerization initiators include radical generators that generate radicals upon irradiation with light and/or heat, acid generators that generate acids, and base generators that generate bases. Specific examples that can be used include benzophenones, glycines, mercaptos, oximes, acylphosphines, α-aminoalkylphenones, quinone diazides, diazodisulfones, triphenylsulfoniums, and diphenyliodoniums.

Examples of polymerizable compounds include polymerizable compounds having (meth)acrylic groups, which are suitable as polymerizable compounds having two or more polymerizable groups, and compounds having two or more epoxy groups, which are suitable as polymerizable compounds having two or more polymerizable groups. These may be used alone or in combination of two or more.

The thickness of the curable sheet 4 is not particularly limited, but is preferably 10 to 200 μm, and more preferably 10 to 50 μm.

The breaking elongation of the curable sheet 4 at 80°C is preferably 400% or more and 3000% or less. A breaking elongation of 400% to 3000% at 80°C is preferable because it better conforms to the uneven shapes of multiple electronic circuit members 2. If the breaking elongation at 80°C is less than 400%, the curable sheet 4 may break when it conforms to the uneven shapes of the electronic circuit members 2 and covers them when the spacing between the electronic circuit members 2 is narrowed to less than 300 μm. Furthermore, if the breaking elongation at 80°C exceeds 3000%, the curable sheet 4 may stretch locally when it conforms to the uneven shapes of the electronic circuit members 2 and covers them, and the curable sheet 4 may enter the internal space S formed by the electronic circuit members 2, bumps 3, and substrate 1.

One method for achieving a breaking elongation of the curable sheet at 80°C of 400% or more and 3000% or less is to control the binder polymer content to 30% or more and 85% or less by mass per 100% by mass of the curable sheet.

The curable sheet 4 may have a single layer structure or a multi-layer structure of two or more layers. If the curable sheet has a multi-layer structure, at least two adjacent layers may have different compositions.

<Polyolefin sheet>
The polyolefin sheet 5 used in the present invention is a sheet containing polyolefin and having a breaking elongation at 80° C. of more than 1000% and less than 3000%.

The other components of the polyolefin sheet are not particularly limited, but examples of polyolefins include olefin polymers having 2 to 30 carbon atoms. One type of polyolefin may be used alone, or two or more types may be used in combination.

Examples of olefins having 2 to 30 carbon atoms include α-olefins having 2 to 30 carbon atoms and dienes having 4 to 30 carbon atoms.

Examples of α-olefins having 2 to 30 carbon atoms include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-pentene, 1-octene, 1-decene, 1-dodecene, 1-icosene, and 1-tetracosene.

The polyolefin sheet 5 may contain a plasticizer to the extent that it is not transferred to the curable sheet 4 in step 2. Examples of plasticizers include hydrocarbons such as liquid paraffin and paraffin wax, esters such as diethylhexyl phthalate and dibutyl phthalate, oleyl alcohol, and stearyl alcohol. It is particularly preferable that the polyolefin sheet does not contain a plasticizer.

As mentioned above, the polyolefin sheet 5 has a breaking elongation at 80°C of greater than 1000% and less than 3000%. A breaking elongation at 80°C of greater than 1000% and less than 3000% is important because it improves the ability of the curable sheet 4 to conform to the uneven shape of the electronic circuit member 2 in step 2. It is also important from the perspective of smoothly peeling the polyolefin sheet in step 3. If the breaking elongation at 80°C is 1000% or less, the polyolefin sheet 5 will not be pressed firmly into the uneven shape of the electronic circuit member 2 in step 2, preventing the curable sheet 4 from conforming to the uneven shape of the electronic circuit member 2 and making it difficult to cover the electronic circuit member 2 with the curable sheet 4. If the breaking elongation at 80°C is 3000% or more, the polyolefin sheet 5 will be pressed too hard when conforming to the uneven shape of the electronic circuit member 2, causing the curable sheet 4 to enter the internal space S formed by the electronic circuit member 2, bumps 3, and substrate 1. Furthermore, if the breaking elongation at 80°C is 3000% or more, tearing will occur when the polyolefin sheet 5 is peeled off in step 3.

Examples of polyolefin sheets with a breaking elongation at 80°C of greater than 1000% and less than 3000% include SAPO-1 (manufactured by Sanyo Kasei Co., Ltd.) and ROMELT (manufactured by Sanyo Kasei Co., Ltd.).

The polyolefin sheet 5 preferably has a breaking strength at 80°C of 5 MPa or more and 20 MPa or less, a storage modulus at 80°C of 15 MPa or less, and a tan δ of less than 0.1. By controlling the breaking strength at 80°C, storage modulus at 80°C, and tan δ of the polyolefin sheet in this manner, it is possible to conform to the uneven shape of the electronic circuit members 2 even when the spacing between the electronic circuit members 2 is narrowed to less than 300 μm, which is preferable.

Examples of polyolefin sheets with a breaking strength at 80°C of 5 MPa or more and 20 MPa or less include SAPO-1 (manufactured by Sanyo Kasei Co., Ltd.) and ROMELT (manufactured by Sanyo Kasei Co., Ltd.).

The thickness of the polyolefin sheet 5 is preferably 10 μm to 200 μm, and more preferably 10 μm to 50 μm.

<Resin sheet>
The resin sheet used in the present invention is a sheet containing a resin, and has a melt viscosity at 80° C. of 10 Pa·s or more and 200,000 Pa·s or less.

The composition of such resin sheet 6 is not particularly limited, but it preferably contains at least one selected from the group consisting of ethylene vinyl acetate, polyolefin, rubber, polyamide, polyester, polyurethane, acrylic copolymer, acrylonitrile-butadiene-styrene resin (ABS), styrene-butadiene-ethylene resin (SEBS), polybutadiene, polyhydroxypolyether, and acrylonitrile-butadiene copolymer (NBR). Among these, polyolefin, polyester, and polyurethane are preferred from the viewpoint of smooth peeling of resin sheet 6 in step 3.

As mentioned above, the resin sheet 6 has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less. By setting the melt viscosity at 80°C of the resin sheet 6 to 10 Pa·s or more and 200,000 Pa·s or less, the pressure required to cause the curable sheet 4 to conform to the uneven shape of the electronic circuit member 2 can be sufficiently transmitted in step 2. If the melt viscosity is greater than 200,000 Pa·s, the pressure required to cause the curable sheet 4 to conform to the uneven shape of the electronic circuit member 2 cannot be sufficiently transmitted in step 2, which may prevent the curable sheet 4 from conforming to the uneven shape of the electronic circuit member 2 and make it difficult to cover the curable sheet 4.

The melt viscosity of the resin sheet 6 at 80°C can be controlled to between 10 Pa·s and 200,000 Pa·s by adjusting the constituent components of the resin sheet 6. For example, the melt viscosity can be controlled by changing the type and amount of resin, or, if multiple resins are used, the ratio of each resin.

The thickness of the resin sheet 6 is preferably such that V > A·Hmax-V', where A is the area of the substrate 1, Hmax is the maximum height of the electronic circuit member 2, V' is the total volume of the electronic circuit member 2, and V is the volume of the resin sheet 4. Specifically, the thickness of the resin sheet 6 is preferably 50 μm to 500 μm.

The area A of the substrate 1 is the surface area of the substrate 1 on which the electronic circuit members 2 are mounted, assuming that no electronic circuit members 2 are mounted and that the substrate 1 has no surface roughness. Furthermore, Hmax is the maximum height of an electronic circuit member 2, among the multiple electronic circuit members 2 mounted on the substrate 1, when the point of contact with the substrate 1 is used as the reference point. The total volume V' of the electronic circuit members 2 is the sum of the volumes of all electronic circuit members 2 mounted on the substrate 1, including the internal spaces S. Finally, the volume V of the resin sheet 4 is the volume calculated from the area and thickness of the resin sheet 4 used.

A·Hmax-V' represents the total volume of the recess formed by the substrate 1 and electronic circuit member 2, and it is preferable that the volume of the resin sheet 4 used be larger than this total volume of the recess.

<Electronic Components>
The substrate 1 is, for example, at least one selected from the group consisting of a semiconductor element, a semiconductor package, a glass substrate, a resin substrate, a ceramic substrate, and a Si substrate. These substrates may have a conductive material layer, such as an anisotropic conductive film or an anisotropic conductive paste, formed on their surfaces. The resin substrate may be a rigid resin substrate or a flexible substrate, and examples thereof include an epoxy resin substrate (e.g., a glass epoxy substrate), a bismaleimide triazine substrate, a polyimide resin substrate, and a fluororesin substrate. The substrate may also be a component-embedded substrate that includes a semiconductor chip or the like inside.

The electronic circuit member 2 is a member mounted on the substrate, and multiple electronic circuit members, such as at least a first member 21 and a second member 22, are used. In the illustrated example, two electronic circuit members are provided per substrate, but this is not limited to this case; for example, three or more electronic circuit members may be provided. In the case of three or more electronic circuit members, the distance D between the electronic circuit members may be different or the same. The height H21 of the first member 21 and the height H22 of the second member 22 may be different or the same, as in the illustrated example. Even when the distances between multiple electronic circuit members are different and/or the heights of the multiple electronic circuit members are different, the structure of the present invention allows the curable sheet to conform to the uneven shape of the electronic circuit member 2 while maintaining the internal space S, making it possible to seal multiple electronic circuit members mounted on the substrate 1 all at once.

In the manufacturing method of the present invention, it is preferable that the relationship 1 < (2H + D)/D < 10 be satisfied, where D is the distance between two adjacent electronic circuit members and H is the average height of the two electronic circuit members. If (2H + D)/D ≥ 10, it may be difficult for the polyolefin sheet 5 to conform to the uneven shape of the electronic circuit member 2.

The electronic circuit component 2 is mounted on the substrate 1 via bumps 3, and an internal space S may be formed between them. Examples of electronic circuit components 2 that require the formation of an internal space S between them and the substrate 1 include SAW, RFIC, sensor chips, piezoelectric resonator chips, quartz resonator chips, and MEMS devices. Examples of electronic circuit components 2 that do not require the formation of an internal space S between them and the substrate 1 include FBAR, BAW, chip multilayer LFC filters, dielectric filters, and multilayer ceramic capacitors (MLCCs).

In other words, the electronic component of the present invention can have a chip-on-board (CoB) structure (including chip-on-wafer (CoW), chip-on-film (CoF), and chip-on-glass (CoG)) in which electronic circuit members 2 are mounted on various substrates 1, a chip-on-chip (CoC) structure, a chip-on-package (CoP) structure, or a package-on-package (PoP) structure. The electronic component may also be a multilayer electronic component in which a substrate 1 on which electronic circuit members 2 are mounted is further laminated with another substrate 1 and/or electronic circuit members 2.

The bumps 3 are conductive, and the substrate 1 and the electronic circuit member 2 are electrically connected via the bumps 3. The height of the bumps 3 is not particularly limited, but may be, for example, 5 μm or more and 150 μm or less. The material of the bumps 3 is also not particularly limited as long as it is conductive, and examples include copper, gold, solder balls, etc.

The electronic component obtained by the manufacturing method of the present invention preferably has an internal space formed by the electronic circuit member and the substrate (Figure 5). Electronic components that need to be sealed while maintaining an internal space include SAW, RFIC, sensor chips, piezoelectric resonator chips, quartz resonator chips, and MEMS devices.

<Sealing process (process 2)>
Step 2 is a step of sealing the electronic circuit member by applying heat and pressure to cause the curable sheet to conform to the uneven shape of the electronic circuit member 2. When a laminate is used in carrying out step 0, the curable sheet in the laminate 7 is sealed by applying heat and pressure to cause it to conform to the uneven shape of the electronic circuit member 2 ( FIG. 2 ). This allows the electronic circuit member 2 to be sealed while maintaining the internal space S. When sealing the electronic circuit member 2 with the laminate 7 in this way, the polyolefin sheet 5 and the resin sheet 6 also deform to conform to the electronic circuit member 2. This inertial deformation of the polyolefin sheet 5 and the resin sheet 6 allows the curable sheet 4 to also conform to the uneven shape of the electronic circuit member 2.

More specifically, when the laminate 7 is pressed against the electronic circuit member 2 while being heated, as shown in Figure 2, the resin sheet 6 melts and acts as a pressure transmission medium, causing the curable sheet 4 and polyolefin sheet 5 to expand and conform to the uneven shape of the electronic circuit member 2, with the resin sheet 6 filling the spaces between the electronic circuit member 2. The inertial deformation of the polyolefin sheet 5 and resin sheet 6 allows the curable sheet 4 to conform to the uneven shape of the electronic circuit member 2. Furthermore, the presence of the polyolefin sheet 5 between the curable sheet 4 and the resin sheet 6 allows the curable sheet 4 to expand without tearing, ensuring high sealing performance.

The heating conditions during pressing are not particularly limited as long as they are below the melting point of the polyolefin sheet 5, and can be set appropriately depending on the pressing method and the type of polyolefin sheet 5. Heating is performed at a temperature of 40°C or higher and 100°C or lower, or 60°C or higher and 80°C or lower. The heating time is not particularly limited, but is, for example, 1 to 600 seconds.

In addition, pressing may be performed in a pressurized atmosphere, at atmospheric pressure, or in a reduced pressure atmosphere (10 Pa or more and 0.1 MPa or less).

Pressing can be performed by any known method as long as it can press the laminate 7 onto the electronic circuit member 2. Pressing can be performed, for example, using a press or a laminator. Alternatively, the laminate 7 can be made to conform to the electronic circuit member 2 while applying pressure to the laminate 7 from the side opposite the substrate 1. Alternatively, the laminate 7 can be made to conform to the electronic circuit member 2 while reducing the pressure in the space between the laminate 7 and the substrate 1.

<Removal process (process 3)>
Step 3 is a step of peeling and removing the polyolefin sheet and the resin sheet. More specifically, in this step, the polyolefin sheet 5 and the resin sheet 6 are removed from the curable sheet 4, polyolefin sheet 5, and resin sheet 6 that were attached to the electronic circuit member 2 in step 2 ( FIG. 3 ). This results in an electronic component in which the electronic circuit member 2 is sealed with the curable sheet 4 ( FIG. 4 ).

More specifically, the polyolefin sheet 5 and resin sheet 6 are preferably peeled off at a temperature below the melting point of the polyolefin sheet, for example, 80°C or below, or at room temperature (specifically, 23°C to 35°C). At such temperatures, the polyolefin sheet 5 has high elasticity, and this elasticity can be used to easily peel the polyolefin sheet 5 and resin sheet 6 from the curable sheet 4.

<Curing process (process 4)>
Step 4 is a step of curing the curable sheet to convert it into a cured layer. That is, the curable sheet 4 sealed in the electronic circuit member 2 is heated at a curing temperature to form a cured product 41 of the curable sheet ( FIG. 5 ). The heating conditions for the curable sheet 4 may be set appropriately depending on the types of thermosetting resin, curing agent, curing accelerator, polymerization initiator, and polymerizable compound contained in the curable sheet 4, and the curing of the curable sheet 4 is carried out at a temperature of 50° C. or higher and 230° C. or lower, for example. The heating time is not particularly limited, but is, for example, 1 second to 300 minutes.

The method for curing the curable sheet 4 is not particularly limited. For example, the curable sheet 4 may be cured by irradiating the entire surface or a pattern of the sheet with light to promote the reaction of the photosensitive component. The light to be irradiated is preferably the i-line (365 nm), h-line (405 nm), or g-line (436 nm) of a mercury lamp, but is not particularly limited.

A mask with the desired pattern may be formed on the curable sheet 4 encapsulated in the electronic circuit component 2, and the curable sheet 4 may be irradiated with light through the mask to expose the curable sheet 4 in a pattern. The unexposed areas may then be removed with a developer to form the pattern (Figure 6). Preferred developers include aqueous solutions of alkaline compounds such as tetramethylammonium, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethylaminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine. In addition to these alkaline aqueous solutions, polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, and dimethylacrylamide; alcohols such as methanol, ethanol, and isopropanol; esters such as ethyl lactate and propylene glycol monomethyl ether acetate; and ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone may also be used as needed.

After pattern formation, the curable sheet 4 sealed to the electronic circuit member 2 is heated at a curing temperature to convert it into a cured layer. The heating conditions for the curable sheet 4 can be set appropriately depending on the types of thermosetting resin, curing agent, curing accelerator, polymerization initiator, and polymerizable compound contained in the curable sheet 4. The curing of the curable sheet 4 is carried out, for example, at a temperature of 50°C or higher and 230°C or lower. There are no particular restrictions on the heating time, but it can be, for example, from 1 second to 300 minutes.

After the curable sheet 4 has been removed by development, multiple new electronic circuit components may be mounted on the substrate 1 (Figure 7).

<Second sealing process (process 5)>
After the curable sheet 4 sealed to the electronic circuit component 2 is heated at a curing temperature, or after multiple electronic circuit components are newly mounted on the substrate 1 from which the curable sheet 4 has been removed by pattern formation, sealing may be performed again with a material (curable material) different from the curable sheet 4, and the material may be heated to a curing temperature to convert it into a hardened layer (Figure 8).

Known curable materials can be used, including photocurable materials and thermosetting materials. The curable material may be in liquid or sheet form. Examples of photocurable and thermosetting materials include resin compositions containing polymerizable compounds, curing agents, and thermosetting resins. Thermosetting materials may also be curable materials that have functionality such as electrical conductivity, heat dissipation, electromagnetic wave shielding, and electromagnetic wave absorption.

<Electronic Components>
The electronic component obtained by the manufacturing method of the present invention preferably has a hollow structure, i.e., an internal space, formed by the electronic circuit member and the substrate. As described above, examples of electronic components that need to be sealed while maintaining an internal space include SAW, RFIC, sensor chips, piezoelectric resonator chips, quartz resonator chips, and MEMS devices.

<<Laminate of the present invention>>
The laminate of the present invention is a laminate used for producing an electronic component having a substrate, a plurality of electronic circuit members mounted on the substrate, and a cured layer, and is a laminate obtained by laminating a curable sheet, a polyolefin sheet, and a resin sheet in this order, wherein the polyolefin sheet has a breaking elongation at 80°C of more than 1000% and less than 3000%, and the resin sheet has a melt viscosity at 80°C of 10 Pa s or more and 200,000 Pa s or less.

Details of the curable sheet, polyolefin sheet, and resin sheet in the laminate of the present invention are as described in the section on the manufacturing method of the present invention.

Furthermore, the polyolefin sheet in the laminate of the present invention has a breaking elongation at 80°C of more than 1000% and less than 3000%, as explained in the section on the manufacturing method of the present invention.

Furthermore, the resin sheet in the laminate of the present invention has a melt viscosity at 80°C of 10 Pa·s or more and 200,000 Pa·s or less, as explained in the section on the manufacturing method of the present invention.

The laminate of the present invention can be suitably used in the manufacture of substrates, multiple electronic circuit components mounted on the substrate, and electronic components having a cured layer.

Furthermore, in the laminate of the present invention, it is preferable that the curable sheet have a breaking elongation at 80°C of 400% or more and 3000% or less. This point is as explained in the section on the manufacturing method of the present invention.

Furthermore, it is preferable that the curable sheet in the laminate of the present invention contains a thermosetting resin. This point is as explained in the section on the manufacturing method of the present invention.

Furthermore, it is preferable that the polyolefin sheet in the laminate of the present invention has a breaking strength at 80°C of 5 MPa or more and 20 MPa or less, a storage modulus at 80°C of 15 MPa or less, and a tan δ of less than 0.1. This is as explained in the section on the manufacturing method of the present invention.

Furthermore, the resin sheet in the laminate of the present invention preferably contains at least one selected from the group consisting of ethylene vinyl acetate, polyolefin, rubber, polyamide, polyester, polyurethane, acrylic copolymer, acrylonitrile-butadiene-styrene resin (ABS), styrene-butadiene-ethylene resin (SEBS), polybutadiene, polyhydroxypolyether, and acrylonitrile-butadiene copolymer (NBR). This point is as explained in the section on the manufacturing method of the present invention.

The following examples and comparative examples will explain in detail the method for manufacturing electronic components of the present invention and the curable sheets used therein, but the present invention is not limited in any way by these examples.

<Examples 1 to 13, Comparative Example 1>
(1) Preparation of a coating solution for a curable sheet The following binder polymer, curable resin, polymerizable compound, polymerization initiator, curing agent, curing accelerator, and other additives were blended to obtain the compositions shown in Table 1, and the blend was stirred and dissolved in a DMF/MIBK mixed solvent at 40°C to give a solids concentration of 20% by weight to prepare a coating solution for a curable sheet.

In the examples where inorganic fillers were used, the inorganic fillers were weighed out to achieve the compounding ratios shown in the table and mixed in a mixer for 2 minutes. While further stirring the inorganic filler, a silane coupling agent was sprayed onto the inorganic filler using a spray bottle to achieve the compounding ratio specified for each example. After silane treatment, the other raw materials and solvent were added, stirred, and dissolved to prepare a coating solution.

<Binder polymer>
Binder polymer 1: SGP-3 (manufactured by Nagase ChemteX Corporation): an epoxy group-containing acrylic copolymer whose main component is butyl acrylate.

<Curable resin>
Curable resin 1: bisphenol A-type epoxy (jER1001, epoxy equivalent 474, manufactured by Mitsubishi Chemical Corporation, solid at room temperature) (however, if a cationic polymerization initiator is selected, curable resin 1 also functions as a polymerizable compound. In other words, curable resin 1 corresponds to a polymerizable compound having two or more polymerizable groups.)
Curable resin 2: Cresol novolac epoxy (EOCN-102S, epoxy equivalent 217, manufactured by Nippon Kayaku Co., Ltd., solid at room temperature) (However, if a cationic polymerization initiator is selected, the curable resin 2 also functions as a polymerizable compound. In other words, the curable resin 2 corresponds to a polymerizable compound having two or more polymerizable groups.)
Curable resin 3: Trisphenolmethane epoxy (EPPN-501H, epoxy equivalent 166, manufactured by Nippon Kayaku Co., Ltd., solid at room temperature) (However, if a cationic polymerization initiator is selected, the curable resin 3 also functions as a polymerizable compound. In other words, the curable resin 3 corresponds to a polymerizable compound having two or more polymerizable groups.)
Curable resin 4: Bisphenol A novolac epoxy (N-865, epoxy equivalent 205, manufactured by DIC) (However, if a cationic polymerization initiator is selected, curable resin 4 also functions as a polymerizable compound. In other words, curable resin 4 corresponds to a polymerizable compound having two or more polymerizable groups.)
<Polymerizable compound>
Polymerizable compound 1: DPE-6A (a polymerizable compound having two or more polymerizable groups, manufactured by Kyoeisha Chemical Co., Ltd.)
<Polymerization initiator>
Polymerization initiator 1: Irgacure OXE04 (radical photopolymerization initiator, manufactured by BASF)
Polymerization initiator 2: CPI-310FG (cationic photopolymerization initiator, manufactured by San-Apro Co., Ltd.)
Polymerization initiator 3: thermal cationic catalyst (Sanaid SI-B3, manufactured by Sanshin Chemical Industry Co., Ltd.)
<Curing agent>
Curing agent 1: 4,4'-diaminodiphenyl sulfone (Seikacure S, amine equivalent 62, manufactured by Wakayama Seika Kogyo Co., Ltd.)
<Curing accelerator>
Curing accelerator 1: Imidazole catalyst (C17Z, manufactured by Shikoku Chemical Industries, Ltd.)
<Inorganic filler>
Inorganic filler 1: spherical silica (SO-E1, average particle size 0.3 μm, manufactured by Admatechs Co., Ltd.)
<Silane coupling agent>
Silane coupling agent 1: 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)
(2) Coating and drying on protective film This coating solution was applied using a bar coater to a 38 μm thick polyethylene terephthalate film with a silicone release agent ("Film Vina" GT, manufactured by Fujimori Kogyo Co., Ltd.) to the dry thickness specified for each example and comparative example, and dried at a temperature of 50° C. for 60 seconds, then at a temperature of 150° C. for 60 seconds. A protective film was then attached to produce a curable sheet of the present invention.

(3) Polyolefin Sheet, Resin Sheet Polyolefin sheets and resin sheets having the properties shown in Table 2 were used.

(4) Breaking elongation and breaking strength A tensile test was carried out on each of the curable sheet and the polyolefin sheet at a speed of 1000 mm/min under conditions of 80°C using a tensile tester (AG-X20kNX, manufactured by Shimadzu) with a chuck distance of 10 mm and a width of 10 mm. The stress-strain curve up to break was recorded, and the breaking elongation and breaking strength were determined.

The breaking elongation is the ratio (= (L1 - L0))/L0 x 100 (%) of the difference (= L1 - L0) between the length of the test specimen when it breaks (L1) and the initial length of the test specimen (L0). The breaking elongation is measured for multiple (e.g., five) test specimens and averaged to determine the average elongation.

(5) Melt Viscosity A resin sheet was laminated under the conditions of a laminating roll temperature of 80°C, a laminating pressure of 0.3 MPa, and a laminating speed of 1 m/min to prepare a sample with a thickness of approximately 800 μm. The laminated sample was cut into a circle with a diameter of 15 mm, and the melt viscosity was measured using a viscoelasticity measuring device (TA Instruments, AR-G2) under the conditions of a shear rate of 50 s-1, a strain of 1%, and a heating rate of 5°C/min, and the complex viscosity |η*| at 80°C was read.

(6) Storage modulus and tan δ
Evaluation was carried out using a polyolefin sheet test piece. The test piece used was 10 mm wide. For evaluation, a dynamic viscoelasticity device (manufactured by SII, DMS6100) was used to determine the storage modulus and tan δ at 80°C under conditions of a frequency of 1 Hz and a heating rate of 5°C/min. Tan δ is the ratio of the storage modulus G' to the loss modulus G" of the polyolefin sheet at 80°C: G"/G'.

(7) Coverage evaluation:
The coverability when covering the surface of a substrate on which a plurality of electronic circuit components were mounted with a curable sheet was evaluated by the following procedure.

The substrate used, on which multiple electronic circuit components were mounted, was an alumina substrate on which evaluation Si chips measuring 0.9 mm wide x 1.1 mm long x 0.2 mm high were flip-chip mounted via 0.04 mm high solder bumps. The Si chips were mounted in 5 rows x 6 columns in the center of the 10 mm x 10 mm alumina substrate, with the spacing between the mounted Si chips being 0.5 mm between the first and second, third and fourth, and fifth and sixth columns, 0.1 mm between the second and third, and fourth and fifth columns, and 0.5 mm between each row.

The curable sheet, polyolefin sheet, and resin sheet were cut to the same area as the above-mentioned substrate, and were placed on multiple electronic circuit components mounted on the above-mentioned substrate in the order of curable sheet, polyolefin sheet, and resin sheet (Step 1). These were then vacuum-laminated using a vacuum laminator (Nikko Materials, CVP-300T) at a temperature of 80°C, a vacuum time of 100 seconds, a pressure time of 300 seconds, and a vacuum pressure of 0.8 MPa (Step 2). The polyolefin sheet and resin sheet were then peeled and removed (Step 3), and the electronic circuit components covered with the curable sheet were heated in an air oven at 150°C for 2 hours to convert them into a cured layer (Step 4).

Next, the appearance after covering with the curable sheet was judged according to the following criteria.

(a) Curable sheet conformability between the first and second columns, the third and fourth columns, the fifth and sixth columns, and the spaces between each row Whether the curable sheet conformed to the irregularities formed by mounting Si chips on the alumina substrate was judged by microscopic observation. A curable sheet that was not torn and that conformed sufficiently to the recesses was judged as ⊚, a curable sheet that was torn or had two or more locations where it did not conform sufficiently to the recesses was judged as x, and a curable sheet that was not torn and had only one location where it did not conform sufficiently to the recesses was judged as ◯.

(b) Appearance of the curable sheets in the second and third rows, and the fourth and fifth rows Whether the curable sheets conformed to the irregularities formed by mounting Si chips on the alumina substrate was judged by microscope observation. A curable sheet that was not torn and conformed sufficiently to the recesses was judged as ⊚, a curable sheet that was torn or had two or more locations where it did not conform sufficiently to the recesses was judged as x, and a curable sheet that was not torn and had only one location where it did not conform sufficiently to the recesses was judged as ◯.

The evaluation results for the various physical properties and coating properties of the curable sheet, polyolefin sheet, and resin sheet are summarized in Table 2.

The present invention solves problems such as tearing and insufficient conformance to uneven shapes, even when multiple electronic circuit components are arranged at different distances, improving yield in the processing process and producing highly reliable electronic components.

10, 11: Electronic component 1: Substrate 2: Electronic circuit member 21: First member 22: Second member 23: Third member 3: Bump 4: Curable sheet 41: Cured product of curable sheet 5: Polyolefin sheet 6: Resin sheet 7: Laminate S: Internal space

Claims (11)

1. A method for manufacturing an electronic component having a substrate, a plurality of electronic circuit members mounted on the substrate, and a hardened layer, comprising:
A method for manufacturing an electronic component, comprising the following steps 1 to 4 in this order:
Step 1: A step of arranging a curable sheet, a polyolefin sheet, and a resin sheet in the following order: the substrate, the electronic circuit member, the curable sheet, the polyolefin sheet, and the resin sheet;
The polyolefin sheet has a breaking elongation at 80°C of 1200% or more and 1800% or less ,
The resin sheet has a melt viscosity at 80°C of 60 Pa·s or more and 89,000 Pa·s or less.
Step 2: A step of applying heat and pressure to make the curable sheet conform to the electronic circuit member and seal it.
Step 3: A step of peeling and removing the polyolefin sheet and the resin sheet.
Step 4: Curing the curable sheet to convert it into a cured layer. The method for manufacturing an electronic component according to claim 1 , further comprising the following step 0 before step 1:
Step 0: A step of laminating the curable sheet, the polyolefin sheet, and the resin sheet in this order to form a laminate. The method for manufacturing an electronic component according to any one of claims 1 to 2, wherein V > A·Hmax-V' is satisfied, where A is the area of the substrate, Hmax is the maximum height of the electronic circuit member, V' is the total volume of the electronic circuit member, and V is the volume of the resin sheet. A method for manufacturing an electronic component according to any one of claims 1 to 3, wherein, where D is the distance between two electronic circuit components and H is the average height of the two electronic circuit components, the relationship 1 < (2H + D)/D < 10 is satisfied. 5. The method for manufacturing an electronic component according to claim 1 , wherein the curable sheet contains a thermosetting resin. 6. The method for manufacturing an electronic component according to claim 1, wherein the resin sheet contains at least one selected from the group consisting of ethylene vinyl acetate, polyolefin, rubber, polyamide, polyester, polyurethane, acrylic copolymer, acrylonitrile-butadiene-styrene resin (ABS), styrene-butadiene-ethylene resin (SEBS), polybutadiene, polyhydroxypolyether, and acrylonitrile- butadiene copolymer (NBR). 7. The method for manufacturing an electronic component according to claim 1, wherein the electronic component has an internal space formed by the electronic circuit member and the substrate. A laminate used in the manufacture of an electronic component having a substrate, a plurality of electronic circuit members mounted on the substrate, and a cured layer,
A laminate in which a curable sheet, a polyolefin sheet, and a resin sheet are laminated in this order,
The polyolefin sheet has a breaking elongation at 80°C of 1200% or more and 1800% or less ,
The resin sheet has a melt viscosity at 80°C of 60 Pa·s to 89,000 Pa·s. The laminate according to claim 8 , wherein the curable sheet contains a thermosetting resin. 10. The laminate according to claim 8 , wherein the polyolefin sheet has a breaking strength at 80°C of 5 MPa or more and 20 MPa or less, a storage modulus at 80°C of 15 MPa or less, and a tan δ of less than 0.1. The laminate according to any one of claims 8 to 10, wherein the resin sheet contains at least one selected from the group consisting of ethylene vinyl acetate, polyolefin, rubber, polyamide, polyester, polyurethane, an acrylic copolymer, an acrylonitrile-butadiene-styrene resin (ABS), a styrene-butadiene-ethylene resin (SEBS), polybutadiene , a polyhydroxypolyether, and an acrylonitrile-butadiene copolymer ( NBR ).