Resin sheet, printed wiring board, semiconductor chip package and semiconductor device

Abstract

This resin sheet for forming a solder resist layer comprises a resin composition layer including a resin composition, wherein the resin composition includes (A) a thermosetting resin and (B) an inorganic filler, the specific surface area of the (B) inorganic filler is 3.0 m2 / g or more, and the thickness of the resin composition layer is 20-100 μm.

Description

[Technical Field]

[0001] The present invention relates to a resin sheet for forming a solder resist layer, and to a printed wiring board, a semiconductor chip package, and a semiconductor device using the resin sheet. [Background technology]

[0002] A solder resist layer may be provided as a protective film on the outermost layer of a printed wiring board or a semiconductor chip package. Conventionally, the solder resist layer has generally been formed by providing a layer of a photocurable resin composition and curing the layer through exposure to light. In recent years, it has also been proposed to form the solder resist layer from a thermosetting resin composition (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-65226 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as semiconductor chip packages have become larger, there has been a demand for thicker solder resist layers. However, it has been difficult to form thick solder resist layers using photosensitive resin compositions. Therefore, the present inventors have investigated the use of thermosetting resin compositions to form solder resist layers.

[0005] However, thick solder resist layers produced using conventional thermosetting resin compositions tend to have low light transmittance, which can make it difficult to adjust the position when forming openings in the solder resist layer or when mounting electronic components on the solder resist layer.

[0006] For example, consider a case where a solder resist layer is formed on a substrate and openings are formed in the solder resist layer to communicate with terminal portions provided on the substrate. In this case, the positions of the terminals can be detected by a sensor capable of detecting light transmitted through the solder resist layer, and the positions at which the openings should be formed can be adjusted. However, if the light transmittance of the solder resist layer is low, the intensity of the light to be detected by the sensor becomes weak, making it difficult to accurately detect the positions of the terminals. Therefore, when a conventional thermosetting resin composition with low light transmittance is used, position adjustment can be difficult.

[0007] The present invention has been devised in view of the above-mentioned problems, and aims to provide a resin sheet capable of forming a thick solder resist layer with high light transmittance; and a printed wiring board, a semiconductor chip package, and a semiconductor device that include a solder resist layer formed using the resin sheet. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above-mentioned problems, and as a result, have found that a solder resist layer having high light transmittance even when thick can be formed by using a resin sheet provided with a resin composition layer containing a resin composition comprising in combination (A) a thermosetting resin and (B) an inorganic filler having a specific range of specific surface area, and have completed the present invention. That is, the present invention includes the following.

[0009] [1] A resin sheet for forming a solder resist layer, comprising a resin composition layer containing a resin composition, The resin composition comprises (A) a thermosetting resin and (B) an inorganic filler, (B) The specific surface area of the inorganic filler is 3.0 m 2 / g or more, A resin sheet, wherein the thickness of the resin composition layer is 20 μm or more and 100 μm or less. [2] The resin sheet according to [1], wherein the inorganic filler (B) has an average particle size of 1.5 μm or less. [3] The resin sheet according to [1] or [2], wherein the amount of (B) inorganic filler is 40% by mass or more and 95% by mass or less relative to 100% by mass of the nonvolatile components of the resin composition. [4] The resin sheet according to any one of [1] to [3], wherein the resin composition layer has a thickness of 35 μm or more and 80 μm or less. [5] The resin sheet according to any one of [1] to [4], wherein the thermosetting resin (A) contains an epoxy resin (A-1). [6] The resin sheet according to [5], wherein the epoxy resin (A-1) includes an epoxy resin containing a naphthalene ring. [7] The resin sheet according to any one of [1] to [6], wherein the thermosetting resin (A) contains a phenol resin (A-2). [8] The resin sheet according to any one of [1] to [7], wherein the thermosetting resin (A) contains an active ester resin (A-3). [9] The resin sheet according to any one of [1] to [8], wherein the thermosetting resin (A) contains a maleimide resin (A-4).

[10] The resin sheet according to any one of [1] to [9], wherein the resin composition further contains (C) an elastomer.

[11] The resin sheet according to any one of [1] to

[10] , wherein the resin composition further contains (D) an organic colorant.

[12] The resin sheet according to any one of [1] to

[11] , wherein the cured product of the resin composition has a thickness of 50 μm and a light transmittance at a measurement wavelength of 900 nm of 70% or more.

[13] A printed wiring board comprising a solder resist layer formed from a cured product of the resin composition layer of the resin sheet according to any one of [1] to

[12] .

[14] A semiconductor chip package comprising a solder resist layer formed from a cured product of the resin composition layer of the resin sheet according to any one of [1] to

[12] .

[15] A semiconductor device comprising the printed wiring board according to

[13] or the semiconductor chip package according to

[14] . [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a resin sheet capable of forming a thick solder resist layer with high light transmittance; and a printed wiring board, a semiconductor chip package, and a semiconductor device that include a solder resist layer formed using the resin sheet. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a semiconductor chip package according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with any modifications within the scope of the claims and their equivalents.

[0013] [1. Overview of resin sheet] A resin sheet according to one embodiment of the present invention is a resin sheet for forming a solder resist layer, and includes a resin composition layer. The resin composition layer contains a resin composition, and preferably contains only a resin composition. The resin composition layer has a thickness within a specific range. The resin composition further contains a combination of (A) a thermosetting resin and (B) an inorganic filler having a specific specific surface area. This resin sheet allows the formation of a thick solder resist layer with high light transmittance.

[0014] [2. Thickness of Resin Composition Layer] The thickness of the resin composition layer provided in the resin sheet is usually 20 μm or more, preferably 30 μm or more, more preferably 35 μm or more, and preferably 100 μm or less, more preferably 90 μm or less, and particularly preferably 80 μm or less. Since the resin composition layer of the resin sheet according to this embodiment is thick as described above, a thick solder resist layer can be formed by the cured product of the resin composition layer. The formed thick solder resist layer can have high light transmittance.

[0015] Furthermore, thick solder resist layers generally tend to cause warpage in printed wiring boards and semiconductor chip packages that include such solder resist layers. The resin sheet according to the present embodiment preferably allows for the formation of a solder resist layer that can suppress warpage even when thick. Conventionally widely used photocurable resin compositions have greater cure shrinkage than thermosetting resin compositions, and therefore conventional solder resist layers made of such photocurable resin compositions tend to be prone to significant warpage. Compared to conventional solder resist layers that tend to be prone to significant warpage as described above, the solder resist layer manufactured using the resin sheet according to the present embodiment has a significant advantage in that it can be made thick while suppressing warpage.

[0016] [3.(A) Thermosetting resin] The resin composition contains a thermosetting resin (A) as component (A). The thermosetting resin (A) may be a resin that can be cured when heat is applied. The thermosetting resin (A) may be used alone or in combination of two or more.

[0017] [3.1.(A-1) Epoxy Resin] The (A) thermosetting resin preferably contains an (A-1) epoxy resin as the component (A-1). The (A-1) epoxy resin is a curable resin having an epoxy group. Examples of the (A-1) epoxy resin 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, and glycidyl ether-type epoxy resins. Examples of the epoxy resin include ester-type epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-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, cyclohexane dimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, isocyanurate-type epoxy resins, and phenolphthalimidine-type epoxy resins. The (A-1) epoxy resin may be used alone or in combination of two or more.

[0018] From the viewpoint of obtaining a cured product having excellent heat resistance, the epoxy resin (A-1) preferably contains an epoxy resin containing an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and also includes polycyclic aromatic rings and aromatic heterocycles. Examples of epoxy resins containing an aromatic structure include 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, bisxyleneol type epoxy resins, glycidylamine type epoxy resins having an aromatic structure, glycidyl ester type epoxy resins having an aromatic structure, cresol novolac type epoxy resins, biphenyl type epoxy resins, linear aliphatic epoxy resins having an aromatic structure, epoxy resins having a butadiene structure having an aromatic structure, alicyclic epoxy resins having an aromatic structure, heterocyclic epoxy resins, spiro ring-containing epoxy resins having an aromatic structure, cyclohexanedimethanol type epoxy resins having an aromatic structure, naphthylene ether type epoxy resins, trimethylol type epoxy resins having an aromatic structure, and tetraphenylethane type epoxy resins having an aromatic structure.

[0019] Among epoxy resins containing an aromatic ring structure, epoxy resins containing a naphthalene ring are preferred. Use of an epoxy resin containing a naphthalene ring improves compatibility with other resins and further reduces warpage.

[0020] From the viewpoint of obtaining a cured product having excellent heat resistance and adhesion, the epoxy resin (A-1) preferably contains an epoxy resin containing a nitrogen atom, such as a glycidylamine-type epoxy resin.

[0021] The epoxy resin (A-1) preferably contains an epoxy resin having two or more epoxy groups per molecule, and 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.

[0022] Epoxy resins include epoxy resins that are liquid at a temperature of 20°C (hereinafter sometimes referred to as "liquid epoxy resins") and epoxy resins that are solid at a temperature of 20°C (hereinafter sometimes referred to as "solid epoxy resins"). The epoxy resin (A-1) contained in the resin composition may be a liquid epoxy resin alone, a solid epoxy resin alone, or a combination of a liquid epoxy resin and a solid epoxy resin.

[0023] The liquid epoxy resin is preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0024] Preferred liquid epoxy resins include 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, cyclohexane type epoxy resins, cyclohexane dimethanol type epoxy resins, and epoxy resins having a butadiene structure.

[0025] Specific examples of liquid epoxy resins include "HP4032", "HP4032D", and "HP4032SS" (naphthalene type epoxy resins) manufactured by DIC Corporation; "828US", "828EL", "jER828EL", "825", and "Epikote 828EL" (bisphenol A type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER807" and "1750" (bisphenol F type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolac type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", and "604" (glycidylamine type epoxy resins) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (glycyrol type epoxy resin) manufactured by ADEKA Corporation; and "EP-3950L" and "EP-3980S" ( Examples of suitable epoxy resins include glycidylamine epoxy resins, ADEKA's "EP-4088S" (dicyclopentadiene epoxy resin), Nippon Steel Chemical & Material's "ZX-1059" (a mixture of bisphenol A and bisphenol F epoxy resins), Nagase ChemteX's "EX-721" (glycidyl ester epoxy resin), Daicel's "Celloxide 2021P" (alicyclic epoxy resin with an ester structure), Daicel's "PB-3600," Nippon Soda's "JP-100" and "JP-200" (epoxy resins with a butadiene structure), and Nippon Steel Chemical & Material's "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resin). These may be used alone or in combination.

[0026] As the solid epoxy resin, a solid epoxy resin having three or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having three or more epoxy groups in one molecule is more preferred.

[0027] 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, and phenolphthalimidine-type epoxy resins.

[0028] Specific examples of solid epoxy resins include "HP4032H" (naphthalene type epoxy resin) manufactured by DIC Corporation; "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resins) manufactured by DIC Corporation; "N-690" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "N-695" (cresol novolac type epoxy resin) manufactured by DIC Corporation; "HP-7200", "HP-7200HH", "HP-7200H", and "HP-7200L" (dicyclopentadiene type epoxy resins) manufactured by DIC Corporation; and "EXA-7311" and "E" manufactured by DIC Corporation. XA-7311-G3, EXA-7311-G4, EXA-7311-G4S, HP6000, HP6000L (naphthylene ether type epoxy resin); Nippon Kayaku Co., Ltd.'s "EPPN-502H" (trisphenol type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC7000L" (naphthol novolac type epoxy resin); Nippon Kayaku Co., Ltd.'s "NC3000H", "NC3000", "NC3000L", "NC3000FH", "NC3100" (biphenyl type epoxy resin); Nippon Steel Chemical & Material Co., Ltd.'s "ESN475V", "ESN4100V" (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. Examples include "YX7700" (phenol aralkyl type epoxy resin); "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "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.

[0029] When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is preferably 20:1 to 1:10, more preferably 10:1 to 1:5, and particularly preferably 5:1 to 1:2.

[0030] The epoxy equivalent of the (A-1) epoxy resin is preferably 50 g / eq to 5,000 g / eq, more preferably 60 g / eq to 3,000 g / eq, even more preferably 80 g / eq to 2,000 g / eq, and particularly preferably 110 g / eq to 1,000 g / eq. The epoxy equivalent represents the mass of the resin per equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

[0031] The weight-average molecular weight (Mw) of the epoxy resin (A-1) 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 by gel permeation chromatography (GPC) as a polystyrene-equivalent value.

[0032] The amount of the (A-1) epoxy resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 4% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less. When the amount of the (A-1) epoxy resin is within this range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is preferable that the tackiness of the resin composition layer be suppressed and the melt viscosity be reduced, and the elastic modulus of the cured product of the resin composition layer be suppressed and the adhesion be improved.

[0033] The amount of (A-1) epoxy resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 15% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less. Unless otherwise specified, the resin components of the resin composition refer to the non-volatile components of the resin composition excluding (B) inorganic filler. When the amount of (A-1) epoxy resin is within the above range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is preferable that the tackiness and melt viscosity of the resin composition layer be suppressed, and the elastic modulus and adhesion of the cured product of the resin composition layer be suppressed.

[0034] Consider the ratio "W(A-1) / {W(B)×S(B)}" obtained by dividing the mass W(A-1) of the epoxy resin (A-1) in the resin composition by the product W(B)×S(B), where W(B) is the mass of the inorganic filler (B) in the resin composition and S(B) is the specific surface area. This ratio "W(A-1) / {W(B)×S(B)}" corresponds to the amount of epoxy resin (A-1) per unit surface area of the inorganic filler (B). From the viewpoint of significantly achieving the desired effects of the present invention, this ratio "W(A-1) / {W(B)×S(B)}" is preferably 0.1×10 -3 g / m 2 More preferably, 1.0 × 10 -3 g / m 2 More preferably, 2.0 × 10 -3 g / m 2 or more, preferably 22 × 10 -3 g / m 2 Less than or equal to 18 × 10 -3 g / m 2 Below, particularly preferably 16 × 10 -3 g / m 2 The following is the result.

[0035] [3.2.(A-2) Phenolic Resin] The (A) thermosetting resin preferably contains (A-2) phenolic resin as component (A-2). The phenolic resin may be a compound having one or more, preferably two or more, phenolic hydroxyl groups per molecule. A phenolic hydroxyl group refers to a hydroxyl group bonded to an aromatic ring such as a benzene ring or a naphthalene ring. In particular, the (A-2) phenolic resin is preferably used in combination with the (A-1) epoxy resin. When the (A-1) epoxy resin and the (A-2) phenolic resin are used in combination, the (A-2) phenolic resin can function as a curing agent that reacts with the (A-1) epoxy resin to cure the resin composition.

[0036] From the viewpoint of heat resistance and water resistance, the (A-2) phenolic resin is preferably a phenolic resin having a novolac structure. From the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferred, and a triazine skeleton-containing phenolic resin is more preferred. Among them, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a triazine skeleton-containing phenolic novolac resin is preferred.

[0037] Specific examples of the (A-2) phenolic resin include, for example, "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000" manufactured by Meiwa Chemical Industry Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-375," and "SN-395" manufactured by Nippon Steel Chemical & Material Co., Ltd.; Examples include "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "LA-1356", "TD2090", "TD-2090-60M", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Company C, and "GDP-6115L" and "GDP-6115H" manufactured by Gun-ei Chemical Co., Ltd.

[0038] The (A-2) phenolic resin may be used alone or in combination of two or more.

[0039] The hydroxyl group equivalent of the (A-2) phenolic resin 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 hydroxyl group equivalent represents the mass of the resin per equivalent of hydroxyl groups.

[0040] When the number of epoxy groups in the (A-1) epoxy resin is taken as 1, the number of hydroxyl groups in the (A-2) phenolic resin is preferably 0.01 or more, more preferably 0.10 or more, even more preferably 0.15 or more, and preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of epoxy groups in the (A-1) epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resins present in the resin composition by the epoxy equivalent. Furthermore, the "number of hydroxyl groups in the (A-2) phenolic resin" refers to the total value obtained by dividing the mass of the non-volatile components of the phenolic resins present in the resin composition by the hydroxyl equivalent.

[0041] The amount of (A-2) phenolic resin in the resin composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, relative to 100% by mass of nonvolatile components in the resin composition, and is preferably 20% by mass or less, more preferably 15% by mass or less, particularly preferably 10% by mass or less. When the amount of (A-2) phenolic resin is within this range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is preferable that the tackiness of the resin composition layer be suppressed and the melt viscosity be reduced, and the elastic modulus of the cured product of the resin composition layer be suppressed and the adhesion be improved.

[0042] The amount of (A-2) phenolic resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 3% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 35% by mass or less. When the amount of (A-2) phenolic resin is within this range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is preferable that the tackiness of the resin composition layer be suppressed and the melt viscosity be reduced, and the elastic modulus of the cured product of the resin composition layer be suppressed and the adhesion be improved.

[0043] The ratio W(A-2) / W(B) of the mass W(A-2) of the phenolic resin (A-2) in the resin composition to the mass W(B) of the inorganic filler (B) in the resin composition is preferably within a specific range from the viewpoint of significantly achieving the desired effects of the present invention. Specifically, the ratio W(A-2) / W(B) is preferably 0.1 × 10 -2 or more, more preferably 0.5 × 10 -2 More preferably, 1.0 × 10 -2 or more, preferably 20.0 × 10 -2 or less, more preferably 15.0 × 10 -2 Below, particularly preferably 10.0 × 10 -2 The following is the result.

[0044] Consider the ratio "W(A-2) / {W(B)×S(B)}" obtained by dividing the mass W(A-2) of the (A-2) phenolic resin in the resin composition by the product W(B)×S(B), where W(B) is the mass of the (B) inorganic filler in the resin composition and S(B) is the specific surface area. This ratio "W(A-2) / {W(B)×S(B)}" corresponds to the amount of (A-2) phenolic resin per unit surface area of the (B) inorganic filler. From the viewpoint of significantly achieving the desired effects of the present invention, this ratio "W(A-2) / {W(B)×S(B)}" is preferably 0.5×10 -3 g / m 2 More preferably, 1.0 × 10 -3 g / m 2 More preferably, 2.0 × 10 -3 g / m 2or more, preferably 10 × 10 -3 g / m 2 Less than or equal to 8.0 × 10 -3 g / m 2 Below 6.0 × 10, particularly preferably -3 g / m 2 The following is the result.

[0045] [3.3.(A-3) Active ester resin] The (A) thermosetting resin preferably contains an (A-3) active ester resin as component (A-3). The (A-3) active ester resin is generally a compound having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, or esters of heterocyclic hydroxy compounds. In particular, the (A-3) active ester resin is preferably used in combination with the (A-1) epoxy resin. When the (A-1) epoxy resin and the (A-3) active ester resin are used in combination, the (A-3) active ester resin can function as a curing agent that reacts with the (A-1) epoxy resin to cure the resin composition.

[0046] The (A-3) active ester resin is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. From the viewpoint of improving heat resistance in particular, an active ester resin obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferred. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, 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 compounds" refers to diphenol compounds obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0047] Specifically, the (A-3) active ester resin is preferably a dicyclopentadiene-type active ester resin, a naphthalene-type active ester resin containing a naphthalene structure, an active ester resin containing an acetylated product of phenol novolac, or an active ester resin containing a benzoylated product of phenol novolac, and among these, at least one selected from dicyclopentadiene-type active ester resins and naphthalene-type active ester resins is more preferred. As the dicyclopentadiene-type active ester resin, an active ester resin containing a dicyclopentadiene-type diphenol structure is preferred.

[0048] Commercially available products of the (A-3) active ester resin include, for example, active ester resins containing a dicyclopentadiene-type diphenol structure, such as "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); and active ester resins containing a naphthalene structure, such as "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", and "EXB- Examples of activated ester resins include "EXB9401" (manufactured by DIC Corporation), which is a phosphorus-containing activated ester resin; "DC808" (manufactured by Mitsubishi Chemical Corporation), which is an acetylated product of phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), which are benzoylated products of phenol novolac; and "PC1300-02-65MA" (manufactured by Air Water Inc.), which is an activated ester resin containing a styryl group and a naphthalene structure.

[0049] The (A-3) active ester resin may be used alone or in combination of two or more.

[0050] The active ester group equivalent of the (A-3) active ester resin 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 active ester group equivalent represents the mass of the resin per equivalent of the active ester group.

[0051] When the number of epoxy groups in the (A-1) epoxy resin is taken as 1, the number of active ester groups in the (A-3) active ester resin is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.10 or more, and is preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. The "number of active ester groups in the (A-3) active ester resin" refers to the total value obtained by dividing the mass of the non-volatile components of the active ester resins present in the resin composition by the active ester group equivalent.

[0052] The amount of the (A-3) active ester resin in the resin composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, particularly preferably 2% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. When the amount of the (A-3) active ester resin is within the above range, the desired effects of the present invention can be significantly achieved.

[0053] The amount of the (A-3) active ester resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, and is preferably 20% by mass or less, more preferably 10% by mass or less, particularly preferably 5% by mass or less, based on 100% by mass of the resin components of the resin composition. When the amount of the (A-3) active ester resin is within the above range, the desired effects of the present invention can be significantly achieved.

[0054] [3.4.(A-4) Maleimide Resin] The thermosetting resin (A) preferably contains a maleimide resin (A-4) as the component (A-4). The maleimide resin may be a compound containing at least one, preferably two or more, maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrol-1-yl groups) per molecule. The ethylenic double bond contained in the maleimide group of the maleimide resin (A-4) can undergo radical polymerization. Furthermore, the maleimide resin (A-4) can react with the epoxy resin (A-1) in the presence of a suitable catalyst such as an imidazole compound. Therefore, the maleimide resin (A-4) can thermoset the resin composition through these reactions.

[0055] The (A-4) maleimide resin may be an aliphatic maleimide resin containing an aliphatic amine skeleton, an aromatic maleimide resin containing an aromatic amine skeleton, or a combination thereof. The (A-4) maleimide resin may be used alone or in combination of two or more.

[0056] Examples of (A-4) maleimide resins include "SLK-2600" manufactured by Shin-Etsu Chemical Co., Ltd.; "BMI-1500," "BMI-1700," "BMI-689," and "BMI-2500" (dimer diamine structure-containing maleimide compounds) manufactured by Designer Molecules, Inc.; "BMI-6100" (aromatic maleimide compound) manufactured by Designer Molecules, Inc.; "MIR-5000-60T" and "MIR-3000-70MT" (biphenylaralkyl maleimide compounds) manufactured by Nippon Kayaku Co., Ltd.; "BMI-70" and "BMI-80" manufactured by K.I. Chemical Industry Co., Ltd.; and "BMI-2300" and "BMI-TMH" manufactured by Daiwa Chemical Industry Co., Ltd. Further, examples of the (A-4) maleimide resin include the maleimide resin (indan ring skeleton-containing maleimide compound) disclosed in Japan Institute of Invention and Innovation's Disclosure Technical Bulletin No. 2020-500211.

[0057] The amount of the (A-4) maleimide resin in the resin composition is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and particularly preferably 2.0% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less. When the amount of the (A-4) maleimide resin is within the above range, the desired effects of the present invention can be significantly achieved.

[0058] The amount of the (A-4) maleimide resin in the resin composition is preferably 1% by mass or more, more preferably 4% by mass or more, and particularly preferably 6% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 30% by mass or less. When the amount of the (A-4) maleimide resin is within the above range, the desired effects of the present invention can be significantly achieved.

[0059] The ratio W(A-4) / W(B) of the mass W(A-4) of the maleimide resin (A-4) in the resin composition to the mass W(B) of the inorganic filler (B) in the resin composition is preferably within a specific range from the viewpoint of significantly achieving the desired effects of the present invention. Specifically, the ratio W(A-4) / W(B) is preferably 0.1 × 10 -2 More preferably, 1.0 × 10 -2 More preferably, 2.0 × 10 -2 More preferably, 3.1 × 10 -2 or more, preferably 30 × 10 -2 Less than or equal to 20 × 10 -2 Below, particularly preferably 15 × 10 -2 The following is the result.

[0060] Consider the ratio "W(A-4) / {W(B)×S(B)}" obtained by dividing the mass W(A-4) of the maleimide resin (A-4) in the resin composition by the product W(B)×S(B), where W(B) is the mass of the inorganic filler (B) in the resin composition and S(B) is the specific surface area. This ratio "W(A-4) / {W(B)×S(B)}" can correspond to the amount of the maleimide resin (A-4) per unit surface area of the inorganic filler (B). From the viewpoint of significantly achieving the desired effects of the present invention, this ratio "W(A-4) / {W(B)×S(B)}" is preferably 0.5×10 -3 g / m 2 More preferably, 1.0 × 10 -3 g / m 2 More preferably, 1.5 × 10 -3 g / m 2 or more, preferably 20 × 10 -3 g / m 2 Less than or equal to 15 × 10 -3 g / m 2 Below, particularly preferably 11 × 10 -3 g / m 2 The following is the result.

[0061] [3.5. Other thermosetting resins] Other examples of (A) thermosetting resins include cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. When used in combination with (A-1) epoxy resin, these resins can function as curing agents that react with (A-1) epoxy resin to cure the resin composition. Further examples of (A) thermosetting resins include (A-4) radically polymerizable resins other than maleimide resins. These radically polymerizable resins generally have ethylenically unsaturated bonds and can be cured by radical polymerization. Examples of radically polymerizable resins include styrene-based radically polymerizable resins having one or more vinyl groups directly bonded to aromatic carbon atoms, and allylic radically polymerizable resins having one or more allyl groups. These resins may be used alone or in combination.

[0062] The number average molecular weight (Mn) of the thermosetting resin (A), including the above-mentioned components (A-1) to (A-4), is preferably less than 3,000, more preferably less than 2,000, and even more preferably 1,500 or less, and is preferably 100 or more, more preferably 250 or more, and even more preferably 400 or more. The number average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

[0063] [3.6.(A) Amount of Thermosetting Resin] The amount of (A) thermosetting resin in the resin composition is preferably 1% by mass or more, more preferably 2% by mass or more, and particularly preferably 5% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, and particularly preferably 25% by mass or less. When the amount of (A) thermosetting resin is within this range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is preferable that the tackiness of the resin composition layer be suppressed and the melt viscosity be reduced, and the elastic modulus of the cured product of the resin composition layer be suppressed and the adhesion be improved.

[0064] The amount of (A) thermosetting resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more, relative to 100% by mass of the resin components of the resin composition, and is preferably 90% by mass or less, more preferably 85% by mass or less, and particularly preferably 80% by mass or less. When the amount of (A) thermosetting resin is within this range, the light transmittance of the cured product of the resin composition layer can be effectively increased. Furthermore, it is usually possible to suppress the tackiness and reduce the melt viscosity of the resin composition layer, as well as suppress the elastic modulus and improve the adhesion of the cured product of the resin composition layer.

[0065] [4.(B) Inorganic filler] The resin composition contains an inorganic filler (B) as component (B). The inorganic filler (B) is usually contained in the resin composition in the form of particles. The inorganic filler (B) has a specific surface area within a specific range.

[0066] (B) The range of specific surface area of inorganic fillers is usually 3.0m 2 / g or more, preferably 3.5m 2 / g or more, more preferably 4.0m 2 / g or more, and 5.0m 2 / g or more, 10.0m 2 / g or more or 20.0m 2 / g or more. When the (B) inorganic filler contained in the resin composition has a specific surface area within the above range, the light transmittance of the cured product of the resin composition layer can be increased. Furthermore, it is preferable that the tackiness of the resin composition layer be suppressed and the melt viscosity be reduced, and that the modulus of elasticity of the cured product of the resin composition layer be suppressed and the adhesion be improved. From the viewpoint of significantly obtaining the desired effects of the present invention, the upper limit of the specific surface area of the (B) inorganic filler is preferably 100 m 2 / g or less, more preferably 70m 2 / g or less, more preferably 50m 2 / g or less, particularly preferably 40m 2 / g or less.

[0067] (B) The specific surface area of the inorganic filler can be measured according to the BET method by adsorbing nitrogen gas onto the sample surface 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.

[0068] (B) Inorganic fillers are inorganic compounds. Examples of (B) 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 and alumina are preferred, and silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. The (B) inorganic filler may be used alone or in combination of two or more.

[0069] The average particle size of the (B) inorganic filler is preferably 1.5 μm or less, more preferably 1.0 μm or less, more preferably 0.6 μm or less, particularly preferably 0.4 μm or less, and preferably 0.01 μm or more, more preferably 0.05 μm or more. When the average particle size of the (B) inorganic filler is within the above range, the light transmittance of the cured resin composition layer can be effectively increased. Furthermore, it is usually possible to suppress the tackiness and reduce the melt viscosity of the resin composition layer, as well as suppress the elastic modulus and improve the adhesion of the cured resin composition layer.

[0070] (B) The average particle size of an inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction / scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The volumetric particle size distribution of the inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red wavelength light sources using a flow cell system, and the average particle size can be calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

[0071] (B) The inorganic filler is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a fluorine-containing silane coupling agent, an aminosilane coupling agent, an epoxysilane coupling agent, a mercaptosilane coupling agent, a silane coupling agent, an alkoxysilane, an organosilazane compound, and a titanate coupling agent. One type of surface treatment agent may be used alone, or two or more types may be used in any combination.

[0072] Examples of commercially available surface treatment agents include 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).

[0073] The degree of surface treatment with the surface treatment agent preferably falls within a specific range from the viewpoint of improving the dispersibility of (B) the inorganic filler. Specifically, 100% by mass of the inorganic filler is preferably surface-treated with 0.2% to 5% by mass of the surface treatment agent, more preferably with 0.2% to 3% by mass of the surface treatment agent, and even more preferably with 0.3% to 2% by mass of the surface treatment agent.

[0074] The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is set to 0.02 mg / m 2 More than 0.1 mg / m is preferable. 2 More preferably, 0.2 mg / m or more 2 On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin composition, it is more preferable that the content be 1.0 mg / m 2 Preferably less than 0.8 mg / m 2 Less than 0.5 mg / m is more preferable. 2 The following is even more preferred:

[0075] (B) The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated 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 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 solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. The carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

[0076] The amount of (B) inorganic filler in the resin composition is preferably 40% by mass or more, more preferably 50% by mass or more, and particularly preferably 60% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 95% by mass or less, more preferably 90% by mass or less, and particularly preferably 85% by mass or less. When the amount of (B) inorganic filler is within the above range, the linear thermal expansion coefficient of the cured product of the resin composition can be reduced, thereby suppressing expansion and contraction due to temperature changes, improving the dimensional stability of the solder resist layer, and suppressing crack formation. Generally, the thicker the solder resist layer, the greater the degree of expansion and contraction. Therefore, being able to reduce the linear thermal expansion coefficient of the cured product as described above is useful in that it can solve problems that are likely to occur in thick solder resist layers.

[0077] [5.(C) Elastomer] The resin composition may further contain an optional component (C) elastomer in addition to the aforementioned components (A) and (B). The component (C) (C) elastomer does not include components (A) and (B). When a resin composition containing the elastomer (C) is used, the elastic modulus of the cured product can be effectively suppressed, thereby effectively suppressing warpage of printed wiring boards and semiconductor chip packages that include a solder resist layer. This suppression of warpage is particularly useful when warpage is generally likely to occur due to a thick solder resist layer or a large amount of inorganic filler (B) in the resin composition.

[0078] The (C) elastomer is a flexible resin, preferably a resin having rubber elasticity or a resin exhibiting rubber elasticity by polymerizing with other components. Examples of rubber elastic resins include resins that exhibit a modulus of elasticity of 1 GPa or less when subjected to a tensile test in accordance with Japanese Industrial Standards (JIS K7161) at a temperature of 25°C and a humidity of 40%RH. One type of (C) elastomer may be used alone, or two or more types may be used in any combination in any ratio.

[0079] The (C) elastomer preferably has a high molecular weight. The number average molecular weight (Mn) of the (C) elastomer is preferably 1,000 or more, more preferably 1,500 or more, even more preferably 2,000 or more, even more preferably 3,000 or more, and particularly preferably 5,000 or more. The upper limit is preferably 1,000,000 or less, more preferably 900,000 or less. The number average molecular weight (Mn) is the number average molecular weight in terms of polystyrene measured using GPC (gel permeation chromatography).

[0080] The (C) elastomer is preferably one or more types selected from resins having a glass transition temperature (Tg) of 25°C or lower and resins that are liquid at 25°C or lower. The glass transition temperature of resins having a glass transition temperature (Tg) of 25°C or lower is preferably 20°C or lower, more preferably 15°C or lower. The lower limit of the glass transition temperature is not particularly limited, but is usually -15°C or higher. Furthermore, resins that are liquid at 25°C are preferably resins that are liquid at 20°C or lower, more preferably resins that are liquid at 15°C or lower. The glass transition temperature can be measured by DSC (differential scanning calorimetry) at a heating rate of 5°C / min.

[0081] As the (C) elastomer, a resin having one or more structures selected from a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polycarbonate structure, and a polystyrene structure in the molecule is preferred. Among these, a resin having one or more structures selected from a polybutadiene structure, a poly(meth)acrylate structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polycarbonate structure, and a polystyrene structure is more preferred. Furthermore, a resin having one or more structures selected from a polybutadiene structure and a polyalkyleneoxy structure is even more preferred, and a resin having a polybutadiene structure is particularly preferred. The term "(meth)acrylate" encompasses methacrylate, acrylate, and a combination thereof. These structures may be contained in the main chain or in the side chain.

[0082] The (C) elastomer may have a functional group capable of reacting with the (A) thermosetting resin. When the (C) elastomer reacts with the (A) thermosetting resin, the mechanical strength of the cured resin composition can be increased. The functional group capable of reacting with the (A) thermosetting resin includes a functional group that appears upon heating. Examples of the functional group capable of reacting with the (A) thermosetting resin include one or more functional groups selected from the group consisting of a hydroxy group, a carboxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, a urethane group, and a maleimide group. Among these, preferred functional groups are a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, a urethane group, and a maleimide group. More preferred are a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, and a maleimide group. Particularly preferred are a phenolic hydroxyl group and a maleimide group. However, the number-average molecular weight (Mn) of the (C) elastomer containing the functional group is preferably 3,000 or more.

[0083] An example of the (C) elastomer is a resin containing a polybutadiene structure. The polybutadiene structure may be contained in the main chain or in a side chain. The polybutadiene structure may be partially or completely hydrogenated. A resin containing a polybutadiene structure is sometimes called a "polybutadiene resin." Specific examples of polybutadiene resins include "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (polybutadienes containing acid anhydride groups) manufactured by Cray Valley Corporation; "GQ-1000" (polybutadiene having hydroxyl and carboxyl groups introduced therein), "G-1000," "G-2000," and "G-3000" (polybutadienes having hydroxyl groups at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydrogenated polybutadiene having hydroxyl groups at both ends) manufactured by Nippon Soda Co., Ltd.; and "FCA-061L" (an epoxy resin with a hydrogenated polybutadiene backbone) manufactured by Nagase ChemteX Corporation. Specific examples of polybutadiene resins include hydroxyl-terminated polybutadiene, linear polyimides made from diisocyanate compounds and tetrabasic acid anhydrides (polyimides described in JP 2006-37083 A and WO 2008 / 153208 A), and phenolic hydroxyl group-containing butadienes. The content of the butadiene structure in the polyimide resin is preferably 60% by mass to 95% by mass, more preferably 75% by mass to 85% by mass. For details of the polyimide resin, please refer to the descriptions in JP 2006-37083 A and WO 2008 / 153208 A, the contents of which are incorporated herein by reference.

[0084] Another example of the (C) elastomer is a resin containing a poly(meth)acrylate structure. A resin containing a poly(meth)acrylate structure is sometimes called a "poly(meth)acrylic resin." Examples of poly(meth)acrylic resins include Teisan Resin manufactured by Nagase ChemteX Corporation, ME-2000, W-116.3, W-197C, KG-25, and KG-3000 manufactured by Negami Chemical Industrial Co., Ltd., and ARUFON UH-2000 manufactured by Toagosei Co., Ltd.

[0085] Another example of the (C) elastomer is a resin containing a polycarbonate structure. Resins containing a polycarbonate structure are sometimes referred to as "polycarbonate resins." Examples of polycarbonate resins include "FPC0220" and "FPC2136" manufactured by Mitsubishi Gas Chemical Company, Inc.; "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals Corporation; and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Alternatively, linear polyimides made from hydroxyl-terminated polycarbonates, diisocyanate compounds, and tetrabasic acid anhydrides may be used. The carbonate structure content of the polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details of the polyimide resin, please refer to the description in WO 2016 / 129541, the contents of which are incorporated herein by reference.

[0086] Another example of the (C) elastomer is a resin containing a polysiloxane structure. Resins containing a polysiloxane structure are sometimes referred to as "siloxane resins." Examples of siloxane resins include "SMP-2006," "SMP-2003PGMEA," and "SMP-5005PGMEA" manufactured by Shin-Etsu Silicones Co., Ltd., and linear polyimides made from amine-terminated polysiloxanes and tetrabasic acid anhydrides (see, for example, International Publication No. 2010 / 053185, JP 2002-12667 A, and JP 2000-319386 A).

[0087] Further examples of the (C) elastomer include resins containing a polyalkylene structure or a polyalkyleneoxy structure. Resins containing a polyalkylene structure are sometimes called "alkylene resins," and resins containing a polyalkyleneoxy structure are sometimes called "alkyleneoxy resins." The number of carbon atoms in the polyalkylene structure and polyalkyleneoxy structure is preferably 2 to 15, more preferably 3 to 10, and even more preferably 5 to 8. Specific examples of alkylene resins and alkyleneoxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Corporation, and "BMI-3000" manufactured by Designer Molecules.

[0088] Another example of the (C) elastomer is a resin containing a polyisoprene structure. A resin containing a polyisoprene structure is sometimes called an "isoprene resin." Specific examples of isoprene resins include "KL-610" and "KL613" manufactured by Kuraray Co., Ltd.

[0089] Another example of the (C) elastomer is a resin containing a polyisobutylene structure. A resin containing a polyisobutylene structure is sometimes called an "isobutylene resin." Specific examples of isobutylene resins include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer), both manufactured by Kaneka Corporation.

[0090] Another example of the (C) elastomer is a resin containing a polystyrene structure. Resins containing a polystyrene structure are sometimes referred to as "styrene resins." The styrene resin may be a copolymer containing, in combination with a styrene unit, any repeating unit different from the styrene unit, or may be a hydrogenated polystyrene resin. Examples of the styrene resin include styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymer (SEEPS), styrene-butadiene-butylene-styrene block copolymer (SBBS), styrene-butadiene diblock copolymer, hydrogenated styrene-butadiene block copolymer, hydrogenated styrene-isoprene block copolymer, hydrogenated styrene-butadiene random copolymer, and styrene-maleic anhydride copolymer. Specific examples of styrene resins include hydrogenated styrene-based thermoplastic elastomers "H1041," "Tuftec H1043," "Tuftec P2000," and "Tuftec MP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "Epofriend AT501" and "CT310" (manufactured by Daicel Corporation); modified styrene-based elastomers having hydroxyl groups "Septon HG252" (manufactured by Kuraray Co., Ltd.); modified styrene-based elastomers having carboxyl groups "Tuftec N503M," modified styrene-based elastomers having amino groups "Tuftec N501," modified styrene-based elastomers having acid anhydride groups "Tuftec M1913" (manufactured by Asahi Kasei Chemicals Corporation); unmodified styrene-based elastomers "Septon S8104" (manufactured by Kuraray Co., Ltd.); and styrene-ethylene / butylene-styrene block copolymers "FG1924" (manufactured by Kraton) and "EF-40" (manufactured by Cray Valley).

[0091] The (C) elastomer may be included in the resin composition and its cured product in a manner compatible with resin components other than the (C) elastomer. Generally, all of the above-mentioned examples are compatible with resin components such as the (A) thermosetting resin. On the other hand, the (C) elastomer may be included in the resin composition and its cured product as particles, without being compatible with resin components other than the (C) elastomer. Such particulate (C) elastomers can generally function as organic fillers. Particulate (C) elastomers can generally exert the same effects as those that are compatible with resin components other than the (C) elastomer. Examples of particulate (C) elastomers include "EXL2655" manufactured by Dow Chemical Japan, and "AC3401N" and "AC3816N" manufactured by Aica Kogyo Co., Ltd.

[0092] The (C) elastomer may be used alone or in combination of two or more.

[0093] The amount of (C) elastomer is preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 4% by mass or more, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, based on 100% by mass of the nonvolatile components in the resin composition. When the amount of (C) elastomer is within this range, the minimum melt viscosity of the resin composition can be lowered, and warping of printed wiring boards and semiconductor chip packages having a solder resist layer can be effectively suppressed.

[0094] The amount of (C) elastomer is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% by mass or less, based on 100% by mass of the resin components in the resin composition. When the amount of (C) elastomer is within this range, the minimum melt viscosity of the resin composition can be lowered, and warping of printed wiring boards and semiconductor chip packages having a solder resist layer can be effectively suppressed.

[0095] [6. (D) Organic Colorants] The resin composition may further contain an optional component (D) organic colorant in combination with the above-described components (A) to (C). The organic colorant (D) as component (D) does not include those corresponding to the above-described components (A) to (C). When a resin composition containing the organic colorant (D) is used, the solder resist layer can be colored in a desired color.

[0096] The organic colorant (D) may be a pigment, a dye, or a combination of these, but is preferably a pigment, which has high coloring ability and can effectively color the solder resist layer.

[0097] Examples of pigments include blue pigments such as phthalocyanine pigments, anthraquinone pigments, and dioxazine pigments. Examples of yellow pigments include monoazo pigments, disazo pigments, condensed azo pigments, benzimidazolone pigments, isoindolinone pigments, and anthraquinone pigments. Examples of red pigments include monoazo pigments, disazo pigments, azo lake pigments, benzimidazolone pigments, perylene pigments, diketopyrrolopyrrole pigments, condensed azo pigments, anthraquinone pigments, and quinacridone pigments. Examples of green pigments include phthalocyanine pigments.

[0098] The (D) organic colorant may be used alone or in combination of two or more.

[0099] The amount of (D) organic colorant is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, and particularly preferably 0.01% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition; and is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 1% by mass or less, and particularly preferably 0.3% by mass or less.

[0100] The amount of (D) organic colorant is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, particularly preferably 0.1% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0101] [7. (E) Thermoplastic Resins] The resin composition may further contain a thermoplastic resin (E) as an optional component in combination with the above-described components (A) to (D). The thermoplastic resin (E) as component (E) does not include those corresponding to the above-described components (A) to (D).

[0102] Examples of the (E) thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polyetheretherketone resin, polyester resin, etc., with phenoxy resin being preferred. The (E) thermoplastic resin may be used alone or in combination of two or more.

[0103] Examples of phenoxy resins include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. One type of phenoxy resin may be used alone, or two or more types may be used in combination. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing a bisphenol A skeleton), "YX8100" (phenoxy resin containing a bisphenol S skeleton), and "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton), all manufactured by Mitsubishi Chemical Corporation. Other examples include "FX280" and "FX293" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," and "YL7482" manufactured by Mitsubishi Chemical Corporation.

[0104] Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins, with polyvinyl butyral resins being preferred. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, and Denka Butyral 6000-EP, manufactured by Denki Kagaku Kogyo Co., Ltd., and S-LEC BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series, manufactured by Sekisui Chemical Co., Ltd.

[0105] Specific examples of polyimide resins include "Rikacoat SN20" and "Rikacoat PN20" manufactured by New Japan Chemical Co., Ltd.

[0106] Specific examples of polyamide-imide resins include "Vylomax HR11NN" and "Vylomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins also include modified polyamide-imides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamide-imides) manufactured by Hitachi Chemical Co., Ltd.

[0107] A specific example of polyethersulfone resin is "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. A specific example of polyphenylene ether resin is "OPE-2St 1200" oligophenylene ether styrene resin manufactured by Mitsubishi Gas Chemical Co., Ltd. A specific example of polyetheretherketone resin is "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd. A specific example of polyetherimide resin is "Ultem" manufactured by GE Corporation.

[0108] Specific examples of polysulfone resins include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0109] Examples of polyolefin resins include ethylene copolymer resins such as low density polyethylene, very low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer.

[0110] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polytrimethylene terephthalate resin, polytrimethylene naphthalate resin, and polycyclohexane dimethyl terephthalate resin.

[0111] The weight average molecular weight (Mw) of the (E) thermoplastic resin is preferably greater than 5,000, more preferably 8,000 or more, even more preferably 10,000 or more, and particularly preferably 20,000 or more, and is preferably 100,000 or less, more preferably 70,000 or less, even more preferably 60,000 or less, and particularly preferably 50,000 or less.

[0112] The amount of (E) thermoplastic resin is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and particularly preferably 1.0% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less.

[0113] The amount of (E) thermoplastic resin is preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less.

[0114] [8. (F) Curing Accelerators] The resin composition may further contain a curing accelerator (F) as an optional component in combination with the above-described components (A) to (E). The curing accelerator (F) as component (F) does not include components (A) to (E) described above. The curing accelerator (F) functions as a curing catalyst that accelerates the curing of the epoxy resin (A-1).

[0115] Examples of the (F) curing accelerator include phosphorus-based curing accelerators, urea-based curing accelerators, guanidine-based curing accelerators, imidazole-based curing accelerators, metal-based curing accelerators, and amine-based curing accelerators. Among these, imidazole-based curing accelerators are preferred. One type of (F) curing accelerator may be used alone, or two or more types may be used in combination.

[0116] Examples of the phosphorus-based curing accelerator include aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitate, tetrabutylphosphonium hydrogenhexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenolate, and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, p-tolyltriphenylphosphonium tetra-p-tolylborate, and tetraphenylphosphonium tetra-p-tolylborate. aromatic phosphonium salts such as tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylethylphosphonium tetraphenylborate, tris(3-methylphenyl)ethylphosphonium tetraphenylborate, tris(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate; aromatic phosphine-borane complexes such as triphenylphosphine-triphenylborane; aromatic phosphine-quinone adducts such as triphenylphosphine-p-benzoquinone adduct; aliphatic phosphines such as tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine;Dibutylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tris(4-ethylphenyl)phosphine, tris(4-propylphenyl)phosphine, tris(4-isopropylphenyl)phosphine, tris(4-butylphenyl)phosphine, tris(4-tert-butylphenyl)phosphine, tris(2,4-dimethylphenyl)phosphine, tris(2,5-dimethylphenyl)phosphine, tris(2,6-dimethylphenyl)phosphine aromatic phosphines such as benzene, tris(3,5-dimethylphenyl)phosphine, tris(2,4,6-trimethylphenyl)phosphine, tris(2,6-dimethyl-4-ethoxyphenyl)phosphine, tris(2-methoxyphenyl)phosphine, tris(4-methoxyphenyl)phosphine, tris(4-ethoxyphenyl)phosphine, tris(4-tert-butoxyphenyl)phosphine, diphenyl-2-pyridylphosphine, 1,2-bis(diphenylphosphino)ethane, 1,3-bis(diphenylphosphino)propane, 1,4-bis(diphenylphosphino)butane, 1,2-bis(diphenylphosphino)acetylene, and 2,2'-bis(diphenylphosphino)diphenyl ether;

[0117] Examples of the urea-based curing accelerator include 1,1-dimethylurea; aliphatic dimethylureas such as 1,1,3-trimethylurea, 3-ethyl-1,1-dimethylurea, 3-cyclohexyl-1,1-dimethylurea, and 3-cyclooctyl-1,1-dimethylurea; 3-phenyl-1,1-dimethylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-(3-chloro-4-methylphenyl)-1,1-dimethylurea, 3-(2-methylphenyl)-1,1-dimethylurea, 3-(4-methylphenyl)-1,1-dimethylurea, and 3-(3,4-dimethylphenyl)-1,1-dimethylurea. aromatic dimethylureas such as toluene bis(dimethylurea), 3-(4-isopropylphenyl)-1,1-dimethylurea, 3-(4-methoxyphenyl)-1,1-dimethylurea, 3-(4-nitrophenyl)-1,1-dimethylurea, 3-[4-(4-methoxyphenoxy)phenyl]-1,1-dimethylurea, 3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea, 3-[3-(trifluoromethyl)phenyl]-1,1-dimethylurea, N,N-(1,4-phenylene)bis(N',N'-dimethylurea), and N,N-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea) [toluene bisdimethylurea].

[0118] Examples of guanidine 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.

[0119] Examples of the imidazole curing accelerator 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, and 1-benzyl-2-methylimidazole. Phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium 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 Examples of imidazole compounds include 2-phenyl-4,5-dihydroxymethylimidazole, 2-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. Commercially available imidazole curing accelerators include "1B2PZ," "2E4MZ," "2MZA-PW," "2MZ-OK," "2MA-OK," "2MA-OK-PW," "2PHZ," "2PHZ-PW," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," and "C11Z-A" manufactured by Shikoku Chemicals Corporation; and "P200-H50" manufactured by Mitsubishi Chemical Corporation.

[0120] Examples of metal-based curing accelerators include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organic cobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organic copper complexes such as copper(II) acetylacetonate, organic zinc complexes such as zinc(II) acetylacetonate, organic iron complexes such as iron(III) acetylacetonate, organic nickel complexes such as nickel(II) acetylacetonate, and organic manganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0121] Examples of the amine curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Commercially available amine curing accelerators may be used, such as "MY-25" manufactured by Ajinomoto Fine-Techno Co., Inc.

[0122] The amount of the (F) curing accelerator in the resin composition is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, and particularly preferably 0.03% by mass or more, relative to 100% by mass of the non-volatile components in the resin composition, and is preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less.

[0123] The amount of the (F) curing accelerator in the resin composition is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and particularly preferably 0.10% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less.

[0124] [9.(G) Optional Additives] In addition to the components (A) to (F), the resin composition may further contain an optional additive (G) as an optional non-volatile component. Examples of the optional additive (G) include radical polymerization initiators such as peroxide radical polymerization initiators and azo radical polymerization initiators; organometallic compounds such as organocopper compounds, organozinc compounds, and organocobalt compounds; polymerization inhibitors such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents such as silicone leveling agents and acrylic polymer leveling agents; thickeners such as bentone and montmorillonite; antifoaming agents such as silicone antifoaming agents, acrylic antifoaming agents, fluorine-based antifoaming agents, and vinyl resin antifoaming agents; ultraviolet absorbers such as benzotriazole ultraviolet absorbers; adhesion improvers such as urea silanes; adhesion promoters such as triazole adhesion promoters, tetrazole adhesion promoters, and triazine adhesion promoters; hindered forms of the additive (G). Examples of the additives include antioxidants such as phenol-based antioxidants; fluorescent brightening agents such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphinic acid compounds, and 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 anhydride-based stabilizers. (G) Optional additives may be used alone or in combination of two or more.

[0125] [10. Amount of Nitrogen-Containing Resin in Resin Composition] The resin components (A) and (C) to (G) preferably contain a resin component containing a nitrogen atom in order to improve the adhesion of the solder resist layer. In particular, when a resin component containing a nitrogen atom is used as part or all of the (A) thermosetting resin, the (C) elastomer, the (E) thermoplastic resin, and the (F) curing accelerator, the adhesion can be effectively improved.

[0126] The amount of the resin component containing a nitrogen atom is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and particularly preferably 2.0% by mass or more, relative to 100% by mass of the non-volatile components in the resin composition, and is preferably 40% by mass or less, more preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0127] The amount of the resin component containing a nitrogen atom is preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, and may be 50% by mass or more, relative to 100% by mass of the resin component in the resin composition. The upper limit is preferably 90% by mass or less, more preferably 80% by mass or less, particularly preferably 75% by mass or less.

[0128] [11.(H) Solvents] The resin composition may further contain a (H) solvent as an optional volatile component in addition to the non-volatile components (A) to (G) described above. An organic solvent is typically used as the (H) solvent. Examples of the organic solvent include ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol-based solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. Examples of suitable solvents include ether ester solvents such as ethyl acetate; ester alcohol solvents such as methyl lactate, ethyl lactate, and methyl 2-hydroxyisobutyrate; ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether (butyl carbitol); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The (H) solvent may be used singly or in combination of two or more.

[0129] The amount of (H) solvent is not particularly limited, but when all components in the resin composition are taken as 100% by mass, it may be, for example, 60% by mass or less, 40% by mass or less, 30% by mass or less, 20% by mass or less, 15% by mass or less, 10% by mass or less, or may even be 0% by mass.

[0130] [12. Method for producing resin composition] The resin composition can be produced, for example, by mixing the above-mentioned components. Some or all of the above-mentioned components may be mixed simultaneously, or they 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.

[0131] [13. Properties of Resin Composition, Resin Composition Layer, and Cured Product Thereof] The cured product obtained by curing the above-mentioned resin composition has high light transmittance. Therefore, a resin sheet having a resin composition layer containing this resin composition can form a solder resist layer with high light transmittance. For example, when the cured product of the resin composition has a thickness of 50 μm and a light transmittance T 900 is preferably 70% or more, more preferably 73% or more, particularly preferably 75% or more, and is usually 100% or less.

[0132] The cured product obtained by curing the above-described resin composition may have low light transmittance in the visible wavelength region. For example, when the cured product of the resin composition has a thickness of 50 μm and a measurement wavelength of 900 nm, the light transmittance T 900 and the light transmittance T of the cured resin composition at a thickness of 50 μm and a measurement wavelength of 550 nm. 550 In one embodiment, the difference in light transmittance T 900 -T 550 is preferably 15% or more, more preferably 20% or more, particularly preferably 25% or more, and is preferably 70% or less, more preferably 60% or less, particularly preferably 50% or less.

[0133] The cured product obtained by curing the above-described resin composition can usually reduce the difference in light transmittance due to differences in thickness. Therefore, the cured product of the resin composition can usually have high light transmittance even when the thickness changes. Due to the recent increase in the size of semiconductor chip packages, solder resist layers tend to become thicker, and thick and thin areas may be formed in the solder resist layer depending on the surface shape of the substrate on which the solder resist layer is formed. When the cured product of the above-described resin composition is applied to a solder resist layer, high light transmittance can be obtained in both thick and thin areas. In particular, since the difference in light transmittance due to differences in thickness can be reduced, high light transmittance can be obtained in both areas even if the thickness difference between the thick and thin areas is large. Therefore, the range of thicknesses of the solder resist layer can be expanded, and the range of substrates to which it can be applied can be expanded.

[0134] For example, the difference ΔT(900nm) between the light transmittance T(40μm / 900nm) of a cured product of the resin composition at a thickness of 40μm and a measurement wavelength of 900nm and the light transmittance T(100μm / 900nm) of a cured product of the resin composition at a thickness of 100μm and a measurement wavelength of 900nm is preferably 0% to 30%, more preferably 0% to 25%, and particularly preferably 0% to 20%. Furthermore, the difference ΔT(550nm) between the light transmittance T(40μm / 550nm) of a cured product of the resin composition at a thickness of 40μm and a measurement wavelength of 550nm and the light transmittance T(100μm / 550nm) of a cured product of the resin composition at a thickness of 100μm and a measurement wavelength of 550nm is preferably 0% to 50%, more preferably 0% to 45%, and particularly preferably 0% to 40%.

[0135] It is preferable that the cured product obtained by curing the above-mentioned resin composition has a large change in light transmittance at wavelengths around 780 nm, which is at the long wavelength end of the visible wavelength range. For example, when the cured product of the resin composition has a thickness of 50 μm and a light transmittance T 700 The thickness of the cured resin composition is 50 μm, and the light transmittance T 800 Relative to T 700 / T800 In one embodiment, the ratio T 700 / T 800 is preferably 0.3 to 0.8, more preferably 0.3 to 0.6, and particularly preferably 0.3 to 0.4.

[0136] The cured product obtained by curing the above-described resin composition may have a small fluctuation in light transmittance in a wavelength range longer than the visible wavelength range. For example, when the cured product of the resin composition has a thickness of 50 μm and a light transmittance T 900 The thickness of the cured resin composition is 50 μm, and the light transmittance T 1500 In one embodiment, the absolute value of the difference in light transmittance |T 900 -T 1500 is preferably 0% to 30%, more preferably 0% to 25%, and particularly preferably 0% to 20%.

[0137] The light transmittance of the cured product of the resin composition can be measured using an ultraviolet / near-infrared spectrophotometer (for example, "UV3100PC" manufactured by Shimadzu Corporation). Specific measurement conditions can be those described in the examples below.

[0138] The resin composition described above preferably has reduced tackiness. Therefore, the resin composition layer can also have low tackiness, thereby improving the handleability of the resin sheet. This tackiness can be expressed by the peel force required to peel off a probe that has been brought into contact with the resin composition layer. In one embodiment, the peel force is preferably less than 0.6 N, more preferably less than 0.4 N.

[0139] The peel force can be measured by the following method: A cylindrical SUS probe having a bottom surface with a diameter of 5 mm is brought into contact with the resin composition layer at a contact speed of 0.5 cm / sec, and a peel force of 1000 gf / cm 2The probe is then pulled away at a rate of 0.5 cm / sec, and the peel force required to peel the sample off is measured as an index of tackiness. Specific measurement methods include those described in the Examples.

[0140] The resin composition preferably has a low melt viscosity. Therefore, when a solder resist layer is formed by encapsulating a circuit board or a semiconductor chip using a resin sheet, the resin composition layer can have good embedding properties. In one embodiment, the minimum melt viscosity of the resin composition in the temperature range of 60°C to 200°C is preferably 20,000 poise or less.

[0141] The minimum melt viscosity of the resin composition can be measured using a dynamic viscoelasticity measuring device under conditions of a measurement temperature interval of 2.5°C and a vibration frequency of 1 Hz / deg while raising the temperature of the resin composition from a starting temperature of 60°C to 200°C at a temperature increase rate of 5°C / min. The specific measurement method can be the method described in the examples.

[0142] The cured product of the resin composition described above can preferably have a small modulus of elasticity. Therefore, warpage of printed wiring boards and semiconductor chip packages having a solder resist layer formed from the cured product of the resin composition layer can be effectively suppressed. In one embodiment, the tensile modulus of elasticity of the cured product obtained by curing the resin composition is preferably 15 GPa or less, more preferably 10 GPa or less, even more preferably 8 GPa or less, and particularly preferably 5 GPa or less. The lower limit is not particularly limited, and may be, for example, 1 GPa or more.

[0143] The tensile modulus of the cured product of the resin composition can be measured at 25°C in accordance with JIS K7127 using a cured product obtained by curing the resin composition under curing conditions of 190°C for 90 minutes. A specific measurement method can be the method described in the examples.

[0144] The cured product of the resin composition preferably has high adhesion to substrates formed with various types of resins. Therefore, the solder resist layer formed by the cured product of the resin composition layer can adhere with high adhesion to the substrate on which the solder resist layer is provided. In one embodiment, the peel strength of the cured product obtained by curing the resin composition against a polyimide film is preferably greater than 2 kgf / cm.

[0145] The peel strength of the cured resin composition can be measured by the following method. A resin composition layer and a polyimide film are laminated together, and the resin composition layer is cured at 180°C for 90 minutes to form a solder resist layer. The polyimide film is then peeled off in the direction perpendicular to the solder resist layer at a rate of 50 mm / min, and the peel strength can be measured. Specific measurement methods can be those described in the Examples.

[0146] The solder resist layer formed from the cured product of the resin composition layer described above can preferably suppress warpage of a printed wiring board and a semiconductor chip package provided with the solder resist layer. In one embodiment, the warpage of a sample substrate corresponding to a semiconductor chip package obtained by forming a solder resist layer on a silicon wafer is preferably 1 mm or less, more preferably 0.8 mm or less, and particularly preferably 0.6 mm or less. The warpage can be measured by forming a solder resist layer as a cured product layer from a cured product of a photosensitive resin composition on a 12-inch silicon wafer and using a shadow moire measurement device (for example, "Thermoire AXP" manufactured by Akorometrix) at 25°C in accordance with JEITA EDX-7311-24, a standard of the Japan Electronics and Information Technology Industries Association. Specific measurement methods that can be used include those described in the examples.

[0147] The present inventors believe that the mechanism by which the above-mentioned excellent characteristics are obtained is as follows. Generally, when the layer of the cured resin composition is thick, the light transmittance of the layer tends to be low. In contrast, the (B) inorganic filler contained in the resin composition according to the above-described embodiment has a small particle size, as can be seen from its large specific surface area. Particles of the (B) inorganic filler having such a small particle size can be smaller than the wavelength of light, thereby suppressing light reflection on the particle surface. In particular, when the composition of the resin component is appropriately adjusted, particle aggregation can be suppressed and the refractive index difference at the interface between the particles and the resin component can be reduced, thereby enabling effective suppression of reflection. Therefore, the cured resin composition can have a high light transmittance. Therefore, a thick solder resist layer with high light transmittance can be realized by using the cured resin composition layer.

[0148] Furthermore, when the cured resin composition layer is thick, the effects of expansion and contraction due to temperature changes in the cured resin layer generally become greater, resulting in reduced dimensional stability and increased cracking. Increasing the amount of inorganic filler is considered a way to suppress expansion and contraction, but high inorganic filler content has traditionally tended to result in lower light transmittance and higher elastic modulus, making warpage more likely. In contrast, the resin composition layer according to the above-described embodiment employs a (B) inorganic filler having a specific surface area within a specific range, enabling a cured product with high light transmittance even when the (B) inorganic filler content is high. Furthermore, the resin composition layer according to the above-described embodiment can employ resin components, such as (A) thermosetting resin and (C) elastomer, that have flexible molecular skeletons as part or all of the resin components combined with the (B) inorganic filler. Therefore, even when the (B) inorganic filler content is high, the elastic modulus of the cured product can be reduced, thereby suppressing warpage in printed wiring boards and semiconductor chip packages equipped with a solder resist layer formed from the cured product.

[0149] Furthermore, the inorganic filler (B) according to the above-described embodiment can be combined with a resin component that can reduce the tackiness and minimum melt viscosity of the resin composition and improve the adhesion of the solder resist layer formed from the cured product of the resin composition layer. Thus, while realizing a thick solder resist layer with high light transmittance, it is possible to further reduce the tackiness and minimum melt viscosity of the resin composition and improve the adhesion of the solder resist layer. However, the technical scope of the present invention is not limited to the mechanism described here.

[0150] [14. Optional components that may be included in the resin sheet] The resin sheet according to one embodiment of the present invention may further include an optional member in combination with the resin composition layer. For example, the resin sheet may include a support as an optional member. Usually, the resin composition layer is provided on the support.

[0151] Examples of the support include films made of plastic materials, metal foils, and release papers, with films made of plastic materials and metal foils being preferred.

[0152] 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"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

[0153] When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0154] The surface of the support that is to be bonded to the resin composition layer may be subjected to a matte treatment, a corona treatment, or an antistatic treatment.

[0155] The support may be a support with a release layer, which has a release layer on the surface that bonds with the resin composition layer. Examples of the release agent 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 products may be used as the support with a release layer, including, for example, "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited, which are PET films having a release layer primarily composed of an alkyd resin-based release agent.

[0156] The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, more preferably 10 μm to 60 μm. When a support with a release layer is used, it is preferable that the thickness of the entire support with a release layer is in the above range.

[0157] The resin sheet according to one embodiment of the present invention may further include a protective film as an optional component in combination with the resin composition layer. Typically, the protective film is provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite to the support). The protective film may be the same as the film that can be used as the support. The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. A resin sheet including a protective film can prevent dust from adhering to the surface of the resin composition layer and scratches.

[0158] [15. Manufacturing method of resin sheet] The method for producing a resin sheet is not particularly limited. The resin sheet may be produced, for example, by applying a liquid resin composition onto a support. Alternatively, the resin sheet may be produced, for example, by a method including dissolving and / or dispersing the resin composition in a solvent to obtain a varnish as a liquid resin composition, and applying this varnish onto a support. The application may be performed using a coating device such as a die coater. Furthermore, after application, drying may be performed as necessary.

[0159] Examples of the solvent include the same solvents as those described as components of the resin composition. One type of solvent may be used alone, or two or more types may be used in combination.

[0160] Drying may be carried out by a drying method such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is usually carried out so that the solvent content in the resin composition layer becomes 10% by mass or less, preferably 5% by mass or less. Although this varies depending on the boiling point of the solvent in the resin composition, for example, when a resin composition containing 30% by mass to 60% by mass of solvent is used, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0161] The resin sheet can be stored in a rolled state. When the resin sheet has a protective film, it can usually be used by peeling off the protective film.

[0162] [16. Printed Wiring Boards] A printed wiring board according to one embodiment of the present invention includes a solder resist layer formed from a cured product of the resin composition layer of the resin sheet described above. The solder resist layer typically has a thickness in the same range as that of the resin composition layer. Even with the aforementioned thickness, the solder resist layer can have high light transmittance. Furthermore, the solder resist layer preferably has a low elastic modulus, thereby making it possible to suppress warpage of printed wiring boards and semiconductor chip packages including the solder resist layer. Furthermore, the solder resist layer can preferably be bonded to a circuit substrate with high adhesion.

[0163] Typically, a printed wiring board comprises a circuit substrate and the above-described solder resist layer provided on the circuit substrate. (I) laminating a resin sheet on a circuit board so that the circuit board and the resin composition layer are bonded to each other; (II) curing the resin composition layer to form a solder resist layer; It can be produced by a production method including the steps of:

[0164] The "circuit board" used in step (I) refers to a substrate on which a solder resist layer is to be formed when manufacturing a printed wiring board, and includes, for example, a substrate having circuit wiring. The layer structure, such as the number of layers of the circuit wiring, is not particularly limited and can be appropriately selected depending on the desired properties of the printed wiring board. This circuit board may also include a semiconductor chip. Examples of circuit boards include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates, and circuit wiring may be formed on one or both sides of these substrates.

[0165] The thickness of the circuit board is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and is preferably 800 μm or less, and may be 600 μm or less, 400 μm or less, etc. The thickness of the circuit board refers to the thickness of the entire circuit board, including the thickness of the surface circuit.

[0166] When circuit wiring is formed on the surface of the circuit board, the thickness of the circuit wiring is not particularly limited, but from the viewpoint of thinning the printed wiring board, it is preferably 40 μm or less, more preferably 30 μm or less, even more preferably 25 μm or less, still more preferably 20 μm or less, 18 μm or less, 16 μm or less, 14 μm or less, 12 μm or less, or 10 μm or less. The lower limit of the thickness of the surface circuit is not particularly limited, and can be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0167] From the viewpoint of suppressing the occurrence of circuit distortion and cracks, the thermal expansion coefficient of the circuit board is preferably 16 ppm / °C or less, more preferably 14 ppm / °C or less, and even more preferably 12 ppm / °C or less. The lower limit of the thermal expansion coefficient of the circuit board depends on the composition of the resin composition used to form the solder resist layer, but is preferably -2 ppm / °C or more, more preferably 0 ppm / °C or more, and even more preferably 4 ppm / °C or more. The thermal expansion coefficient of the circuit board represents the linear thermal expansion coefficient in the temperature range of 25°C to 150°C in the planar direction, obtained by thermomechanical analysis (TMA) using a tensile load method. Examples of thermomechanical analyzers that can be used to measure the linear thermal expansion coefficient of the circuit board include the "Thermo Plus TMA8310" manufactured by Rigaku Corporation and the "TMA-SS6100" manufactured by Seiko Instruments Inc.

[0168] The circuit board and the resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the circuit board from the support side. Examples of a member for thermocompression bonding the resin sheet to the circuit board (hereinafter sometimes referred to as a "thermocompression bonding member") include a heated metal plate (such as a SUS plate) or a metal roll (such as a SUS roll). It is preferable to press the thermocompression bonding member not directly onto the resin sheet, but via an elastic material such as heat-resistant rubber, so that the resin composition layer can sufficiently conform to the irregularities caused by the surface circuits of the circuit board.

[0169] The circuit board and the resin sheet may be laminated by a vacuum lamination method. In the vacuum lamination method, 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 0.098MPa to 1.77MPa, more preferably 0.29MPa to 1.47MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. The lamination is preferably carried out under reduced pressure conditions of 26.7hPa or less.

[0170] The lamination can be performed using a commercially available vacuum laminator, such as a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., or a batch vacuum pressure laminator.

[0171] 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 treatment may be the same as the thermocompression conditions for lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

[0172] When the resin sheet has a support, the support may be removed between step (I) and step (II), or may be removed after step (II).

[0173] In step (II), the resin composition layer is cured to form a solder resist layer made of a cured product of the resin composition layer. The curing of the resin composition layer is usually carried out by thermal curing.

[0174] The thermal curing conditions for the resin composition layer vary depending on the type of resin component contained in the resin composition, but in one embodiment, the curing temperature is preferably 120° C. to 240° C., more preferably 150° C. to 220° C., and even more preferably 170° C. to 210° C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

[0175] The thermal curing may be carried out under atmospheric pressure (normal pressure). The thermal curing may also be carried out multiple times. For example, step (II) may be carried out multiple times before step (III) described below, or step (II) may be carried out one or more times before step (III) described below, and then thermal curing may be carried out one or more times after steps (III) and (IV).

[0176] The method for producing a printed wiring board may further include any step in addition to step (I) and step (II). For example, the method for producing a printed wiring board may include, for example, (III) a step of forming an opening in the solder resist layer, and (IV) a step of desmearing the solder resist layer. When the support is peeled off after step (II), the peeling of the support may be performed between step (II) and step (III), between step (III) and step (IV), or after step (IV).

[0177] In step (III), openings are formed in the solder resist layer. Examples of methods for forming openings include drilling, lasers, and plasma. When forming openings using a laser, examples of laser light sources include carbon dioxide lasers, YAG lasers, and excimer lasers. Among these, carbon dioxide lasers are preferred from the viewpoints of processing speed and cost. The size and shape of the openings may be determined appropriately depending on the design of the printed wiring board.

[0178] In step (IV), the solder resist layer is subjected to a desmear treatment. Smears as resin residues may be present inside the openings formed in step (III). These smears may cause poor electrical connections. Therefore, in step (IV), a desmear treatment may be performed to remove the smears.

[0179] The desmearing treatment may be performed by a dry desmearing treatment, a wet desmearing treatment, or a combination thereof.

[0180] An example of the dry desmear treatment is a desmear treatment using plasma. The desmear treatment using plasma can be performed using a commercially available plasma desmear treatment device. Among the commercially available plasma desmear treatment devices, examples suitable for use in manufacturing printed wiring boards include a microwave plasma device manufactured by Nissin Corporation and an atmospheric pressure plasma etching device manufactured by Sekisui Chemical Co., Ltd.

[0181] Examples of wet desmear treatments include desmear treatments using an oxidizing agent solution, etc. When desmear treatments using an oxidizing agent solution are performed, it is preferable to perform a swelling treatment using a swelling liquid, an oxidation treatment using an oxidizing agent solution, and a neutralization treatment using a neutralizing liquid in this order.

[0182] Examples of swelling liquids include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. Sodium hydroxide solutions and potassium hydroxide solutions are more preferred as alkaline solutions. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. Swelling treatment with a swelling liquid may be performed by immersing the film in the swelling liquid at 30°C to 90°C for 1 to 20 minutes.

[0183] The oxidizing agent solution is preferably an alkaline permanganate aqueous solution, such as a solution prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment using the oxidizing agent solution is preferably carried out by immersing the solder resist layer in the oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

[0184] The neutralizing solution is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan Co., Ltd. The neutralization treatment with the neutralizing solution may be carried out by immersing the surface that has been roughened with an oxidizing agent in the neutralizing solution at 30°C to 80°C for 5 to 30 minutes.

[0185] When the dry desmear treatment and the wet desmear treatment are performed in combination, the dry desmear treatment may be performed first, or the wet desmear treatment may be performed first.

[0186] [17. Semiconductor Chip Package] A semiconductor chip package according to one embodiment of the present invention includes a solder resist layer formed from a cured product of the resin composition layer of the resin sheet described above. The solder resist layer typically has a thickness in the same range as that of the resin composition layer. Even with the aforementioned thickness, the solder resist layer can have high light transmittance. Furthermore, the solder resist layer preferably has a low elastic modulus, thereby suppressing warpage of printed wiring boards and semiconductor chip packages that include the solder resist layer. Furthermore, the solder resist layer can preferably be bonded with high adhesion to components of the semiconductor chip package other than the solder resist layer.

[0187] A semiconductor chip package typically includes a semiconductor chip and a solder resist layer. 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 solder resist layer of a semiconductor chip package other than those exemplified here may be formed from a cured product of the resin composition layer of the resin sheet described above.

[0188] A specific description will be given below using a fan-out type WLP as an example. Fig. 1 is a cross-sectional view schematically showing a semiconductor chip package 100 according to one embodiment of the present invention. As shown in Fig. 1, the semiconductor chip package 100 as an example includes a semiconductor chip 110; a sealing layer 120 formed to cover the periphery of the semiconductor chip 110; a rewiring formation layer 130 as an insulating layer provided on the surface of the semiconductor chip 110 opposite the sealing layer 120; a rewiring layer 140 as a conductor layer; a solder resist layer 150; and bumps 160.

[0189] This method of manufacturing a semiconductor chip package includes, for example, (i) a step of laminating a temporary fixing film on a substrate; (ii) a step of temporarily fixing the semiconductor chip on the temporary fixing film; (iii) forming an encapsulation layer on the semiconductor chip; (iv) peeling the substrate and the temporary fixing film from the semiconductor chip; (v) forming a rewiring formation layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; (vi) forming a rewiring layer as a conductor layer on the rewiring formation layer; and (vii) forming a solder resist layer on the rewiring layer; The method for manufacturing the semiconductor chip package also includes: (viii) a step of performing bumping processing; and (ix) A process of dicing and singulating a plurality of semiconductor chip packages into individual semiconductor chip packages. may also include:

[0190] In step (i), a temporary fixing film is laminated on a substrate. The lamination of the substrate and the temporary fixing film can be carried out in the same manner as the lamination of a circuit substrate and a resin sheet in the method for producing a printed wiring board.

[0191] Examples of the substrate 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 in which glass fibers are impregnated with thermosetting resins such as epoxy resins and then thermoset; and substrates made of bismaleimide triazine resins such as BT resin.

[0192] The temporary fixing film may be a film that can be peeled off from the semiconductor chip and can temporarily fix the semiconductor chip. Commercially available products include "Riva Alpha" manufactured by Nitto Denko Corporation.

[0193] In step (ii), the semiconductor chips are temporarily fixed on the temporary fixing film. The temporary fixing of the 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 conditions such as the shape and size of the temporary fixing film and the number of semiconductor chip packages to be produced. For example, the semiconductor chips may be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

[0194] In step (iii), an encapsulating layer is formed on the semiconductor chip. The encapsulating layer is usually formed by a method including forming a resin composition layer for the encapsulating layer on the semiconductor chip and curing the resin composition layer to form the encapsulating layer. The resin composition layer for the encapsulating layer may be formed from a thermosetting resin composition or a photocurable resin composition. Furthermore, the resin composition layer for the encapsulating layer may be the same as the resin composition layer for forming the solder resist layer described above. This encapsulating layer may be formed, for example, by the same method as the lamination and curing of a resin sheet on a circuit board described in the section on printed wiring boards.

[0195] In step (iv), the substrate and the temporary fixing film are peeled off from the semiconductor chip. It is desirable to adopt an appropriate peeling method according to the material of the temporary fixing film. Examples of peeling methods include a method in which the temporary fixing film is heated, foamed, or expanded to peel off. Other peeling methods include 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 to peel off. In the method in which the temporary fixing film is heated, foamed, or expanded to peel off, the heating conditions are typically 100°C to 250°C for 1 second to 90 seconds or 5 minutes to 15 minutes. In the method in which the adhesive strength of the temporary fixing film is reduced by irradiating it with ultraviolet light to peel off, the irradiation dose of ultraviolet light is typically 10 mJ / cm. 2 ~1000mJ / cm 2 is.

[0196] When the base material and the temporary fixing film are peeled off from the semiconductor chip as described above, the surface of the encapsulating layer is exposed. The manufacturing method of the semiconductor chip package may include polishing the exposed surface of the encapsulating layer. By polishing, the smoothness of the surface of the encapsulating layer can be improved.

[0197] In step (v), 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. Typically, this rewiring formation layer is formed on the semiconductor chip and the encapsulating layer. Any insulating material can be used as the material for the rewiring formation layer. The rewiring formation layer may be formed from a cured product of a resin composition for the rewiring formation layer. The rewiring formation layer may be formed, for example, by a method including forming a resin composition layer and curing the resin composition layer. The resin composition layer for the rewiring formation layer may be formed from a thermosetting resin composition or a photocurable resin composition. Furthermore, the same resin composition layer as the resin composition layer for forming the solder resist layer described above may be used as the resin composition layer for the rewiring formation layer. The rewiring formation layer may be formed, for example, by the same method as the lamination and curing of a resin sheet on a circuit board described in the section on printed wiring boards.

[0198] Via holes may be formed in the rewiring formation layer to provide interlayer connection between the semiconductor chip and the rewiring layer. The shape of the via holes is not particularly limited, but is generally circular (approximately circular). The top diameter of the via holes is, for example, 50 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less. Here, the top diameter of the via holes refers to the diameter of the opening of the via hole on the surface of the rewiring formation layer.

[0199] In step (vi), a rewiring layer is formed as a conductor layer on the rewiring formation layer. The rewiring layer can be formed from a conductor material such as metal. The rewiring layer may be a single metal layer or an alloy layer. The thickness of the rewiring layer depends on the desired design of the semiconductor chip package, but is usually 3 μm to 35 μm, preferably 5 μm to 30 μm. Examples of methods for forming the rewiring layer include plating. For example, a rewiring layer having a desired wiring pattern may be formed by plating using a semi-additive method, a full-additive method, or the like. From the viewpoint of ease of production, the semi-additive method is preferred. Alternatively, steps (v) and (vi) may be repeated to alternately stack rewiring layers and rewiring formation layers (build-up).

[0200] In step (vii), a solder resist layer is formed on the rewiring layer. The solder resist layer is formed using the resin sheet described above. Typically, the solder resist layer is formed by a method including laminating a resin sheet on the rewiring layer so that the rewiring layer and the resin composition layer are bonded, and curing the resin composition layer. The lamination of the resin sheet on the rewiring layer can be performed by the same method as laminating the resin sheet on the circuit board described in the section on the printed wiring board. Furthermore, the curing of the resin composition layer can be performed by the same method as curing the resin composition layer described in the section on the printed wiring board. Furthermore, step (vii) may include, as necessary, forming openings in the solder resist layer and performing a desmear treatment on the solder resist layer. The formation of openings and the desmear treatment can be performed by the same methods as described in the section on the printed wiring board.

[0201] The method for manufacturing a semiconductor chip package may optionally include a step (viii) of forming bumps by solder balls, solder plating, or the like.

[0202] The method for manufacturing a semiconductor chip package may optionally include a step (ix) of dicing and singulating the plurality of semiconductor chip packages into individual semiconductor chip packages.

[0203] [18. Semiconductor Devices] A semiconductor device according to one embodiment of the present invention includes the printed wiring board or the semiconductor chip package. The semiconductor device can be manufactured using the printed wiring board or the semiconductor chip package.

[0204] Examples of semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Example]

[0205] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, unless otherwise specified, the temperature and pressure conditions were room temperature (25°C) and atmospheric pressure (1 atm).

[0206] [Production Example 1. Synthesis of Polymer Resin A] A reaction vessel was charged with 69 g of bifunctional hydroxy-terminated polybutadiene ("G-3000" manufactured by Nippon Soda Co., Ltd., number average molecular weight = 3000, hydroxy group equivalent weight = 1800 g / eq.), 40 g of an aromatic hydrocarbon mixed solvent ("IPZOL 150" manufactured by Idemitsu Petrochemical Co., Ltd.), and 0.005 g of dibutyltin laurate, which were mixed and dissolved uniformly. Once homogeneous, the mixture was heated to 60°C, and 8 g of isophorone diisocyanate ("IPDI" manufactured by Evonik Degussa Japan Co., Ltd., isocyanate group equivalent weight = 113 g / eq.) was added with further stirring, and the reaction was carried out for approximately 3 hours.

[0207] Next, 23 g of cresol novolak resin (DIC Corporation "KA-1160", hydroxyl group equivalent = 117 g / eq.) and 60 g of ethyl diglycol acetate (Daicel Corporation) were added to the reaction mixture, and the mixture was heated to 150 °C with stirring and reacted for about 10 hours. -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end of the reaction, and the reaction mixture was cooled to room temperature. The reaction mixture was then filtered through a 100-mesh filter cloth to obtain a polymer resin having a butadiene structure and a phenolic hydroxyl group (phenolic hydroxyl group-containing butadiene resin: non-volatile components 50% by mass). The number-average molecular weight of polymer resin A was 5,900, and the glass transition temperature was -7°C.

[0208] [Production Example 2: Synthesis of Polymer Resin D] In a reaction vessel, 80 g of polycarbonate diol (number average molecular weight: approximately 1,000, hydroxyl equivalent: 500 g / eq., non-volatile content: 100%, "C-1015N" manufactured by Kuraray Co., Ltd.) and 0.01 g of dibutyltin dilaurate were uniformly dissolved in 37.6 g of diethylene glycol monoethyl ether acetate ("Ethyl Diglycol Acetate" manufactured by Daicel Corporation). Next, the mixture was heated to 50°C, and 27.8 g of toluene-2,4-diisocyanate (isocyanate equivalent: 87.08) was added with further stirring, and the reaction was carried out for approximately 3 hours. After cooling the reaction mixture to room temperature, 14.3 g of benzophenonetetracarboxylic dianhydride (acid anhydride equivalent: 161.1 g / eq), 0.12 g of triethylenediamine, and 84.0 g of diethylene glycol monoethyl ether acetate (Daicel Corporation's "Ethyl Diglycol Acetate") were added, and the mixture was heated to 130°C with stirring and reacted for about 4 hours. -1 The disappearance of the NCO peak was confirmed. The disappearance of the NCO peak was considered to be the end point of the reaction, and the reaction mixture was cooled to room temperature and then filtered through a filter cloth with 100 μm openings to obtain a polymer resin D (non-volatile content 50% by mass) having an imide structure, a urethane structure, and a polycarbonate structure. The number average molecular weight was 8,500.

[0209] [Example 1] Epoxy resin mixture (mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", epoxy equivalent 170 g / eq.) 3 parts, naphthalene epoxy resin (DIC Corporation "HP4032D", epoxy equivalent 140 g / eq.) 3 parts, phenolic hardener (DIC Corporation "LA-3018-50P", active group equivalent approximately 151 g / eq., 2-methoxypropanol solution with 50% non-volatile components) 4 parts, maleimide resin (Desiigner Molecules "BMI-689") 3 parts, inorganic filler 2 (average particle size 0.3 μm, specific surface area 10.5 m 265 parts of silica particles surface-treated with a silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.), 20 parts of polymer resin A (non-volatile component 50%), 0.05 parts of imidazole curing accelerator ("1B2PZ" manufactured by Shikoku Chemical Industry Co., Ltd.), 0.05 parts of organic pigment ("Pigment Green 36" manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd., "CG5370"), 0.05 parts of organic pigment ("Pigment Blue 15:3" manufactured by Toyo Ink Mfg. Co., Ltd., "FG7351"), and 15 parts of methyl ethyl ketone as a solvent were mixed and uniformly dispersed in a high-speed rotating mixer to prepare a resin varnish.

[0210] Next, the resin varnish was uniformly applied to a polyethylene terephthalate film ("Lumirror T6AM" manufactured by Toray Industries, Inc., thickness 38 μm) as a support so that the thickness of the resin composition layer after drying would be 50 μm, and the resin composition layer was formed by drying at 80°C to 120°C (average 100°C) for 6 minutes. A protective film with a rough surface (polypropylene film, "Alphan MA-430" manufactured by Oji F-Tex Co., Ltd., thickness 20 μm) was prepared, and the rough surface of the protective film was attached to the resin composition layer to obtain a resin sheet having a layer structure of support / resin composition layer / protective film.

[0211] [Example 2] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of a naphthylene ether epoxy resin (DIC Corporation "HP6000L", epoxy equivalent: 213 g / eq.) were used. Also, 1.5 parts of an activated ester resin (DIC Corporation "HPC-8000L-65™", an activated ester resin containing a dicyclopentadiene-type diphenol structure, a 1:1 solution of toluene:MEK with 65% nonvolatile content by mass, functional group equivalent: 281 g / eq.) were added to the resin varnish. Furthermore, the amount of the phenolic curing agent (DIC Corporation "LA-3018-50P", nonvolatile content: 50%) was changed from 4 parts to 2 parts. Also, 65 parts of inorganic filler 2 were replaced with inorganic filler 3 (average particle size: 1.0 μm, specific surface area: 4.3 m). 2 / g, 90 parts of silica particles surface-treated with a silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd. Furthermore, the amount of polymer resin A (50% non-volatile component) was changed from 20 parts to 40 parts. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0212] [Example 3] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of a glycidylamine-type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g / eq.) were used. The amount of the phenolic curing agent (DIC Corporation "LA-3018-50P", non-volatile content 50%) was changed from 4 parts to 2 parts. Furthermore, 3 parts of a cresol novolac resin (DIC Corporation "KA-1163", phenolic hydroxyl group equivalent 118 g / eq.) were added to the resin varnish. The amount of maleimide resin (Designer Molecules "BMI-689") was changed from 3 parts to 6 parts. Furthermore, 65 parts of inorganic filler 2 were replaced with inorganic filler 1 (average particle size 0.1 μm, specific surface area 30.1 m). 2 50 parts of silica particles (surface-treated with hexamethyldisilazane (HMDS)) were used. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0213] [Example 4] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059") and 3 parts of the naphthalene-type epoxy resin (DIC Corporation "HP4032D"), 3 parts of a glycidylamine-type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g / eq.) and 3 parts of a dicyclopentadiene-type epoxy resin (DIC Corporation "HP7200", epoxy equivalent 258 g / eq.) were used. Also, instead of 4 parts of the phenolic curing agent (DIC Corporation "LA-3018-50P", non-volatile content 50%), 4 parts of a cresol novolac resin (DIC Corporation "KA-1163", phenolic hydroxyl group equivalent 118 g / eq.) were used. Furthermore, the maleimide resin (Designer Molecules Corporation "BMI-689") was not used. In addition, 20 parts of polymer resin A (50% non-volatile content) was replaced with 10 parts of phenoxy resin (YX7553BH30 manufactured by Mitsubishi Chemical Corporation, a 1:1 solution of cyclohexanone and methyl ethyl ketone (MEK) with a non-volatile content of 30% by mass, Mw=35,000). A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0214] [Example 5] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of a glycidylamine-type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g / eq.) were used. The amount of the phenolic curing agent (DIC Corporation "LA-3018-50P", non-volatile content 50%) was changed from 4 parts to 2 parts. Furthermore, 3 parts of a cresol novolac resin (DIC Corporation "KA-1163", phenolic hydroxyl group equivalent 118 g / eq.) were added to the resin varnish. The amount of maleimide resin (Designer Molecules "BMI-689") was changed from 3 parts to 6 parts. Furthermore, 65 parts of inorganic filler 2 were replaced with inorganic filler 1 (average particle size 0.1 μm, specific surface area 30.1 m). 250 parts of silica particles (surface-treated with hexamethyldisilazane (HMDS)) were used. 20 parts of polymer resin A (50% non-volatile content) were replaced with 10 parts of a hydroxyl-containing acrylic polymer (Toagosei Co., Ltd., "ARUFON UH-2000," weight-average molecular weight 11,000) as an elastomer. Five parts of cyclohexanone were added to the resin varnish. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0215] [Example 6] A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that 4 parts of core-shell polymer particles ("EXL2655" manufactured by Dow Chemical Company) were used as a particulate elastomer instead of 20 parts of polymer resin A (50% non-volatile content), and 5 parts of cyclohexanone were added to the resin varnish.

[0216] [Example 7] A resin varnish and a resin sheet were produced in the same manner as in Example 1, except that 20 parts of polymer resin D (non-volatile content 50% by mass) produced in Production Example 2 was used instead of 20 parts of polymer resin A (non-volatile content 50%).

[0217] [Example 8] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of a glycidylamine-type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g / eq.) were used. The amount of the phenolic curing agent (DIC Corporation "LA-3018-50P", non-volatile content 50%) was changed from 4 parts to 2 parts. Furthermore, 3 parts of a cresol novolac resin (DIC Corporation "KA-1163", phenolic hydroxyl group equivalent 118 g / eq.) were added to the resin varnish. Furthermore, 65 parts of inorganic filler 2 were replaced with inorganic filler 1 (average particle size 0.1 μm, specific surface area 30.1 m). 250 parts of silica particles (silica particles surface-treated with hexamethyldisilazane (HMDS)) were used. Furthermore, 20 parts of polymer resin A (50% non-volatile content) were replaced with 5 parts of bismaleimide resin (Designer Molecules "BMI-3000", molecular weight 3000) as an elastomer. Furthermore, 5 parts of cyclohexanone were added to the resin varnish. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0218] [Comparative Example 1] Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of naphthylene ether epoxy resin (DIC Corporation "HP6000L", epoxy equivalent 213 g / eq.) were used. Also, 1.5 parts of an activated ester resin (DIC Corporation "HPC-8000L-65TM", an activated ester resin containing a dicyclopentadiene-type diphenol structure, a 1:1 solution of toluene:MEK with 65% nonvolatile content by mass, functional group equivalent 281 g / eq.) was added to the resin varnish. Furthermore, the amount of phenolic curing agent (DIC Corporation "LA-3018-50P", nonvolatile content 50%) was changed from 4 parts to 2 parts. Also, 65 parts of inorganic filler 2 were replaced with inorganic filler 4 (average particle size 2.0 μm, specific surface area 2.5 m). 2 / g, silica particles surface-treated with a silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Co., Ltd.) were used. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0219] Comparative Example 2 Instead of 3 parts of the epoxy resin mixture (Nippon Steel Chemical & Material Co., Ltd. "ZX-1059"), 3 parts of naphthylene ether epoxy resin (DIC Corporation "HP6000L", epoxy equivalent 213 g / eq.) were used. Also, 1.5 parts of an activated ester resin (DIC Corporation "HPC-8000L-65TM", an activated ester resin containing a dicyclopentadiene-type diphenol structure, a 1:1 solution of toluene:MEK with 65% nonvolatile content by mass, functional group equivalent 281 g / eq.) was added to the resin varnish. Furthermore, the amount of phenolic curing agent (DIC Corporation "LA-3018-50P", nonvolatile content 50%) was changed from 4 parts to 2 parts. Also, 65 parts of inorganic filler 2 were replaced with inorganic filler 4 (average particle size 2.0 μm, specific surface area 2.5 m). 2 100 parts of the polymer resin A (50% non-volatile component) was used. A resin varnish and a resin sheet were produced in the same manner as in Example 1 except for the above.

[0220] [Evaluation of tackiness of resin composition layer] The tack strength of the resin composition layer was measured using a probe tack tester with a thermostatic chamber ("TE-6002" manufactured by Tester Sangyo Co., Ltd.) Specifically, the protective film of the resin sheet placed in a thermostatic chamber at 25°C was peeled off, and a 5 mm diameter cylindrical probe made of SUS was brought into contact with the resin composition layer at a contact speed of 0.5 cm / sec, and the tack strength was measured at 1000 gf / cm. 2 The test piece was held under a load of 0.4 N for 1 second. The peel force when the probe was then pulled away at 0.5 cm / second was measured and taken as the probe tack (tack force). Measurements were performed three times for each sample, and the average value of each measurement was calculated. An average probe tack (tack force) of less than 0.4 N was judged as "Good", a value of 0.4 to 0.6 N was judged as "Good", and a value of 0.6 N or more was judged as "Poor".

[0221] [Measurement of Melt Viscosity of Resin Composition Layer] The melt viscosity of the resin composition contained in the resin composition layer of the resin sheet was measured using a dynamic viscoelasticity measuring device (Rheosol-G3000 manufactured by UBM). This measurement was performed on a 1g sample taken from the resin composition layer using parallel plates with a diameter of 18mm. The measurement conditions were a starting temperature of 60°C to 200°C, a heating rate of 5°C / min, a measurement temperature interval of 2.5°C, and an oscillation frequency of 1Hz / deg. The minimum melt viscosity was calculated from the measured melt viscosity values. A minimum melt viscosity of 20,000 poise or less was evaluated as "Good", and a minimum melt viscosity of more than 20,000 poise was evaluated as "Poor".

[0222] [Measurement of elastic modulus of cured product] A release PET film ("501010" manufactured by Lintec Corporation, 38 μm thick, 240 mm square) was prepared, having a release-treated surface (release side) and an untreated surface (untreated side). This release PET film was placed on a glass cloth-based epoxy resin double-sided copper-clad laminate ("R5715ES" manufactured by Panasonic Electric Works, Ltd., 0.7 mm thick, 255 mm square) so that the untreated side of the release PET film was in contact with the glass cloth-based epoxy resin double-sided copper-clad laminate. The four edges of the release PET film were fixed to the glass cloth-based epoxy resin double-sided copper-clad laminate with polyimide adhesive tape (10 mm wide).

[0223] The protective film was peeled off from each resin sheet (167 mm × 107 mm square) produced in the Examples and Comparative Examples, and the resin composition layer was centrally laminated to the release surface of the release PET film using a batch-type vacuum pressure laminator (a two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.). Lamination was performed by reducing the pressure to 13 hPa or less for 30 seconds, and then pressing the sheet at 100°C and a pressure of 0.74 MPa for 30 seconds. Next, the support was peeled off, and the resin composition layer was thermally cured under curing conditions of 190° C. for 90 minutes.

[0224] After thermal curing, the polyimide adhesive tape was peeled off, the glass cloth-based epoxy resin double-sided copper-clad laminate was removed, and the release PET film was peeled off to obtain a sheet-like cured product, hereinafter referred to as the "cured product for evaluation."

[0225] The cured product for evaluation was cut into a No. 1 dumbbell-shaped test piece to obtain a test piece. The tensile strength of the test piece was measured using a tensile tester ("RTC-1250A" manufactured by Orientec Co., Ltd.) to determine the modulus of elasticity at 25°C. The measurement was carried out in accordance with JIS K7127. This operation was carried out three times, and the average value is shown in the table.

[0226] [Measurement of light transmittance of cured product] Using an ultraviolet / near-infrared spectrophotometer (Shimadzu Corporation, "UV3100PC"), the above-mentioned cured product for evaluation (thickness: 50 μm) was placed at the entrance opening of an integrating sphere to measure the spectral transmittance, and values were extracted at measurement wavelengths of 550 nm, 700 nm, 800 nm, and 900 nm. The measurement conditions were as follows: measurement wavelength range: 300 nm to 2600 nm, sampling pitch: 1 nm, exposure time: 103 seconds (time from start to finish of measurement), integrating sphere: yes, slit width: 20 nm.

[0227] In addition, cured products for evaluation with thicknesses of 40 μm and 100 μm were produced and their spectral transmittance was measured using the same method as in each example, except that the coating thickness of the resin varnish was changed. From the spectral transmittance of the cured products for evaluation (thickness 40 μm) and (thickness 100 μm), values at measurement wavelengths of 550 nm and 900 nm were extracted.

[0228] [Evaluation of adhesion of cured product] The protective film was peeled from the resin sheet obtained in the above-mentioned Examples and Comparative Examples, and the resin composition layer was placed in contact with a glass cloth-based epoxy resin double-sided copper-clad laminate (Panasonic Electric Works R5715ES, 0.7 mm thick, 255 mm square) using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700"). This lamination was carried out by reducing the pressure to 13 hPa or less for 30 seconds, followed by pressure bonding at 100°C and 0.74 MPa for 30 seconds. The laminated resin sheet was then heat-pressed at atmospheric pressure, 100°C, and 0.5 MPa for 60 seconds to smooth the surface. The support was then peeled off.

[0229] A polyimide film (thickness 12.5 μm, "Kapton 100EN" manufactured by Toray DuPont Co., Ltd.) was prepared. This polyimide film was dried at 130°C for 30 minutes and then laminated onto the resin composition layer. This lamination was carried out under the same conditions as the lamination described above. As a result, an "intermediate composite II" was obtained, which included, in this order, a polyimide film, a resin composition layer, and a glass cloth-based epoxy resin double-sided copper-clad laminate.

[0230] The intermediate laminate II was placed in an oven at 180°C and heated for an additional 90 minutes, thereby thermally curing the resin composition layer and obtaining an "evaluation substrate A" including, in this order, a polyimide film, a solder resist layer as a cured product of the resin composition layer, and a glass cloth-based epoxy resin double-sided copper-clad laminate.

[0231] The adhesion (peel strength) between the polyimide film and the solder resist layer was measured using the evaluation substrate A. This peel strength measurement was performed in accordance with JIS C6481. Specifically, the peel strength measurement was performed by the following procedure. A slit was made in the polyimide film of evaluation substrate A, surrounding a rectangular area 10 mm wide and 100 mm long. One end of this rectangular area was peeled off and gripped with a gripping tool (TSE Corporation, Autocom type testing machine "AC-50C-SL"). A 35 mm long area of the rectangular area was peeled off vertically, and the load (kgf / cm) at the time of peeling was measured as the peel strength. The peeling was performed at room temperature (25°C) at a rate of 50 mm / min.

[0232] The higher the measured peel strength, the better the adhesion between the cured product of the resin composition and the polyimide film. Therefore, the adhesion between the polyimide film and the cured product was evaluated according to the following criteria. "Good": Peel strength exceeds 0.2 kgf / cm. "×": Peel strength is less than 0.2 kgf / cm.

[0233] [Warpage measurement] The protective film was peeled off from the resin sheets prepared in the Examples and Comparative Examples. The resin composition layer was then laminated onto a 12-inch silicon wafer (775 μm thick) using a batch-type vacuum pressure laminator (Nikko Materials Co., Ltd., two-stage build-up laminator "CVP700") to form a 50 μm-thick resin composition layer. The wafer was then heated at 170°C for 240 minutes to thermally cure the resin composition layer. The support was then peeled off to obtain a sample substrate comprising a silicon wafer and a cured resin composition layer. The amount of warping of the sample substrate at 25°C was measured using a shadow moiré measurement device (Akorometrix, "Thermoire AXP"). Measurements were performed in accordance with JEITA EDX-7311-24, a standard of the Japan Electronics and Information Technology Industries Association. Specifically, a virtual plane calculated by the least squares method for all data on the substrate surface in the measurement area was used as a reference plane, and the difference between the minimum and maximum values in the direction perpendicular to the reference plane was determined as the amount of warpage.

[0234] [result] The results of the above-mentioned Examples and Comparative Examples are shown in the following table. In the table, the amount of each component represents the amount of non-volatile components. In the table, the meanings of the abbreviations are as follows: T 900 : Light transmittance of a cured resin composition having a thickness of 50 μm and measured at a wavelength of 900 nm. T 550 : Light transmittance of a cured resin composition having a thickness of 50 μm and measured at a wavelength of 550 nm. T 700 : Light transmittance of a cured resin composition having a thickness of 50 μm and measured at a wavelength of 700 nm. T 800 : Light transmittance of a cured resin composition having a thickness of 50 μm and measured at a wavelength of 800 nm. T(40 μm / 900 nm): Light transmittance of a cured resin composition having a thickness of 40 μm and a measurement wavelength of 900 nm. T(100 μm / 900 nm): Light transmittance of a cured resin composition having a thickness of 100 μm and a measurement wavelength of 900 nm. T(40 μm / 550 nm): Light transmittance of a cured resin composition having a thickness of 40 μm and measured at a wavelength of 550 nm. T(100 μm / 550 nm): Light transmittance of a cured resin composition having a thickness of 100 μm and measured at a wavelength of 550 nm.

[0235] [Table 1] [Explanation of symbols]

[0236] 100 Semiconductor chip packages 110 Semiconductor Chips 120 sealing layer 130 Rewiring formation layer 140 Redistribution layer 150 solder resist layer 160 Bump

Claims

1. A resin sheet for forming a solder resist layer, comprising a resin composition layer containing a resin composition, The resin composition comprises (A) a thermosetting resin, (B) an inorganic filler, and (C) an elastomer, (B) The specific surface area of the inorganic filler is 3.0 m ２ / g or more, The thickness of the resin composition layer is 20 μm or more and 100 μm or less, A resin sheet, wherein the tensile modulus of a cured product obtained by curing a resin composition is 5 GPa or less.

2. (A) The thermosetting resin comprises (A-1) an epoxy resin and (A-2) a phenolic resin having a hydroxyl group equivalent of 100 g / eq. to 1000 g / eq., The resin sheet according to claim 1, wherein the number of hydroxyl groups of the phenolic resin (A-2) is in the range of 0.01 or more and 1.0 or less, when the number of epoxy groups of the epoxy resin (A-1) is 1.

3. A resin sheet as described in claim 1, wherein (C) the elastomer has one or more structures selected from a polybutadiene structure and a polyalkyleneoxy structure.

4. The resin sheet according to claim 1, wherein the inorganic filler (B) has an average particle size of 1.5 μm or less.

5. The resin sheet according to claim 1, wherein the amount of the inorganic filler (B) is 40% by mass or more and 95% by mass or less relative to 100% by mass of the nonvolatile components of the resin composition.

6. The resin sheet according to claim 1 , wherein the resin composition layer has a thickness of 35 μm or more and 80 μm or less.

7. The resin sheet according to claim 1, wherein the thermosetting resin (A) comprises an epoxy resin (A-1).

8. The resin sheet according to claim 7, wherein the epoxy resin (A-1) includes an epoxy resin containing a naphthalene ring.

9. The resin sheet according to claim 1, wherein the thermosetting resin (A) comprises a phenolic resin (A-2).

10. The resin sheet according to claim 1, wherein the thermosetting resin (A) comprises an active ester resin (A-3).

11. The resin sheet according to claim 1, wherein the thermosetting resin (A) comprises a maleimide resin (A-4).

12. The resin sheet according to claim 1 , wherein the resin composition further comprises (D) an organic colorant.

13. The resin sheet according to claim 1 , wherein a cured product of the resin composition has a thickness of 50 μm and a light transmittance at a measurement wavelength of 900 nm of 70% or more.

14. A printed wiring board comprising a solder resist layer formed from a cured product of the resin composition layer of the resin sheet according to any one of claims 1 to 13.

15. A semiconductor chip package comprising a solder resist layer formed from a cured product of the resin composition layer of the resin sheet according to any one of claims 1 to 13.

16. A semiconductor device comprising the printed wiring board according to claim 14.

17. A semiconductor device comprising the semiconductor chip package according to claim 15.

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