Resin films, printed wiring boards, semiconductor wafer packaging and semiconductor devices

Abstract

The present invention relates to a resin sheet for forming a solder resist layer comprising a resin composition layer, wherein the resin composition comprises (A) a thermosetting resin and (B) an inorganic filler, the specific surface area of ​​(B) the inorganic filler is 3.0 m² / g or more, and the thickness of the resin composition layer is 20 μm or more and 100 μm or less.

Description

Technical Field

[0001] This invention relates to a resin sheet for forming a solder resist layer and to printed wiring boards, semiconductor wafer packages, and semiconductor devices using the resin sheet. Prior Technology

[0002] A solder resist layer is provided as a protective film on the outermost layer of printed circuit boards and semiconductor chip packages. Conventionally, the solder resist layer is generally a layer of photocurable resin composition, formed by curing the layer through exposure. More recently, it has been proposed to form the solder resist layer using a thermocurable resin composition (Patent Document 1). [Previous Technical Documents] [Patent Literature]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2016-65226 Summary of the Invention

[0004] [The problem that the invention aims to solve]

[0005] In recent years, with the increasing size of semiconductor wafer packaging, there is a need to increase the thickness of the solder resist layer. However, it is difficult to form a thick solder resist layer using photosensitive resin compositions. Therefore, the inventors have explored the use of thermosetting resin compositions to form the solder resist layer.

[0006] However, thick solder resist layers made using conventional thermosetting resin compositions tend to have low light transmittance. Therefore, when the solder resist layer has low light transmittance, openings may form in the solder resist layer, or the placement of electronic components mounted on the solder resist layer may become difficult.

[0007] For example, consider a case where a solder resist layer is formed on a substrate, and this solder resist layer forms an opening that communicates with a terminal portion disposed on the substrate. In this case, by using light that penetrates the solder resist layer and a sensor capable of detecting this light, the position of the terminal can be detected, and the position of the opening to be formed can be adjusted. However, when the light transmittance of the solder resist layer is low, the intensity of the light detected by the sensor becomes weak, and it may be difficult to accurately detect the position of the terminal. Therefore, when using conventional thermosetting resin compositions with low light transmittance, position adjustment sometimes becomes difficult.

[0008] The present invention was made in view of the aforementioned problems. The object of the present invention is to provide a resin sheet capable of forming a thick solder resist layer with high light transmittance; and a printed wiring board, a semiconductor wafer package, and a semiconductor device having a solder resist layer formed using the resin sheet. [Methods used to solve problems]

[0009] The inventors carefully examined the aforementioned issues. As a result, the inventors discovered that a thick solder resist layer with high light transmittance can be formed by using a resin sheet having a resin composition layer comprising a resin composition containing (A) a thermosetting resin and (B) an inorganic filler having a specific surface area within a certain range, thus completing the present invention. That is, the present invention includes the following.

[0010] [1] A resin sheet, which is a resin sheet for forming a solder resist layer having a resin composition layer comprising a resin composition. The resin composition includes (A) thermosetting resin and (B) inorganic filler. (B) The specific surface area of ​​the inorganic filler is 3.0 m² / g or higher. The thickness of the resin composition layer is 20μm or more and 100μm or less. [2] The resin sheet as in [1], wherein the average particle size of the inorganic filler (B) is less than 1.5 μm. [3] The resin sheet as in [1] or [2], wherein the amount of (B) inorganic filler is 40% to 95% by mass relative to 100% by mass of the non-volatile components of the resin composition. [4] The resin sheet of any one of [1] to [3] has a thickness of 35 μm or more and 80 μm or less. [5] The resin sheet of any one of [1] to [4], wherein (A) the thermosetting resin includes (A-1) epoxy resin. [6] The resin sheet as in [5], wherein (A-1) epoxy resin comprises an epoxy resin containing a naphthalene ring. [7] A resin sheet of any one of [1] to [6], wherein (A) a thermosetting resin comprises (A-2) a phenolic resin. [8] A resin sheet of any one of [1] to [7], wherein (A) a thermosetting resin comprises (A-3) an active ester resin. [9] A resin sheet of any one of [1] to [8], wherein (A) a thermosetting resin comprises (A-4) maleimide resin.

[10] A resin sheet as described in any of [1] to [9], wherein the resin composition further comprises (C) an elastomer.

[11] A resin sheet as described in any of [1] to

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

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

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

[13] A printed wiring board having a solder resist layer formed by a hardened resin composition layer of a resin sheet as described in any of [1] to

[12] .

[14] A semiconductor wafer package having a solder resist layer formed by a hardened resin composition layer of a resin sheet as described in any of [1] to

[12] .

[15] A semiconductor device having a printed wiring board as in

[13] or a semiconductor wafer package as in

[14] . [Invention Effects]

[0011] According to the present invention, a resin sheet capable of forming a thick solder resist layer with high light transmittance can be provided; a printed wiring board, a semiconductor wafer package, and a semiconductor device having a solder resist layer formed using the resin sheet can be provided. Simple Explanation of the Diagram

[0012] [Figure 1] Figure 1 is a schematic cross-sectional view of a semiconductor wafer package according to one embodiment of the present invention. Implementation

[0013] [Forms of Invention Implementation]

[0014] The present invention will now be described with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified in any way without departing from the scope of the claims and their equivalents.

[0015] [1. Overview of Resin Sheets] One embodiment of the present invention provides a resin sheet for forming a solder resist layer, comprising a resin composition layer. The resin composition layer contains a resin composition, preferably only a resin composition. Furthermore, the resin composition layer has a specific range of thickness. Further, the resin composition system combines (A) a thermosetting resin and (B) an inorganic filler having a specific specific surface area. Based on this resin sheet, a thick solder resist layer with high light transmittance can be formed.

[0016] [2. Thickness of the resin composition layer] The thickness of the resin composition layer in the resin sheet is typically 20 μm or more, preferably 30 μm or more, more preferably 35 μm or more, more preferably 100 μm or less, more preferably 90 μm or less, and particularly preferably 80 μm or less. In this embodiment, the resin composition layer of the resin sheet is relatively thick, as described above. Therefore, a thick solder resist layer can be formed by curing this resin composition layer. The resulting thick solder resist layer can then have high light transmittance.

[0017] Furthermore, thicker solder resist layers generally tend to cause warping in printed circuit boards and semiconductor wafer packages. When using the resin sheet according to this embodiment, it is preferable to form a thick solder resist layer that suppresses warping. Conventionally widely used photocurable resin compositions have greater curing shrinkage compared to thermocurable resin compositions; therefore, conventional solder resist layers composed of such photocurable resin compositions tend to exhibit significant warping. The solder resist layer manufactured using the resin sheet of this embodiment has a greater advantage than conventional solder resist layers that are prone to significant warping, as mentioned above, as it can suppress warping even when thicker.

[0018] [3. (A) Thermosetting resin] The resin composition includes (A) thermosetting resin as component (A). (A) thermosetting resin can be a resin that can be cured when heat is applied. (A) thermosetting resin can be used alone or in combination of two or more types.

[0019] [3.1. (A-1) Epoxy Resin] (A) A thermosetting resin, preferably an epoxy resin containing (A-1) as a component (A-1). The epoxy resin (A-1) is a thermosetting resin having epoxy groups. Examples of the epoxy resin (A-1) include bis(xylenol) type epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol phenolic varnish type epoxy resin, phenol phenolic varnish type epoxy resin, tert-butyl-catechol type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, and glycidylamine type epoxy resin. Glyceryl ester type epoxy resin, cresol phenolic varnish epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spirocyclic epoxy resin, cyclohexane type epoxy resin, cyclohexanediol type epoxy resin, naphthylene ether type epoxy resin, tris(hydroxymethyl) type epoxy resin, tetraphenylethane type epoxy resin, isocyanurate type epoxy resin, phenolphthalein imine type epoxy resin, etc. (A-1) Epoxy resins can be used alone or in combination of two or more types.

[0020] (A-1) From the perspective of obtaining a cured epoxy resin with excellent heat resistance, epoxy resins containing aromatic structures are preferred. Aromatic structures refer to chemical structures generally defined as aromatic, and also include polycyclic aromatics and aromatic heterocycles. Examples of epoxy resins containing aromatic structures include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, triphenol type epoxy resin, naphthol phenolic varnish type epoxy resin, phenol phenolic varnish type epoxy resin, tert-butyl-catechol type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, xylenol type epoxy resin, glycidylamine type epoxy resin with aromatic structures, and other epoxy resins with aromatic structures. Glycidyl ester type epoxy resin with aromatic structure, cresol phenolic varnish epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin with aromatic structure, butadiene type epoxy resin with aromatic structure, alicyclic epoxy resin with aromatic structure, heterocyclic epoxy resin, spirocyclic epoxy resin with aromatic structure, cyclohexanediol type epoxy resin with aromatic structure, naphthylene ether type epoxy resin, trihydroxymethyl type epoxy resin with aromatic structure, tetraphenylethane type epoxy resin with aromatic structure, etc.

[0021] Among epoxy resins containing aromatic ring structures, epoxy resins containing naphthalene rings are preferred. By using epoxy resins containing naphthalene rings, good compatibility with other resins can be achieved, further resulting in low warpage.

[0022] (A-1) From the viewpoint of obtaining a cured product with excellent heat resistance and adhesion, epoxy resins containing nitrogen atoms are preferred. Examples of epoxy resins containing nitrogen atoms include glycidylamine type epoxy resins.

[0023] (A-1) Epoxy resin, preferably an epoxy resin containing two or more epoxy groups in one molecule. The proportion of epoxy resin containing two or more epoxy groups in one molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to 100% by mass of the non-volatile components of (A-1) epoxy resin.

[0024] Epoxy resins are available in two forms: liquid epoxy resin at 20°C (hereinafter sometimes referred to as "liquid epoxy resin") and solid epoxy resin at 20°C (hereinafter sometimes referred to as "solid epoxy resin"). The (A-1) epoxy resin contained in the resin composition may be liquid epoxy resin, solid epoxy resin, or a combination of liquid and solid epoxy resin.

[0025] Liquid epoxy resin, preferably a liquid epoxy resin having two or more epoxy groups in one molecule.

[0026] Liquid epoxy resins are preferably bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidylamine type epoxy resins, phenolic varnish type epoxy resins, alicyclic epoxy resins with ester skeletons, cyclohexane type epoxy resins, cyclohexanediethanol type epoxy resins, and epoxy resins with butadiene structures.

[0027] Specific examples of liquid epoxy resins include: DIC's "HP4032", "HP4032D", and "HP4032SS" (naphthalene-type epoxy resin); Mitsubishi Chemical's "828US", "828EL", "jER828EL", "825", and "Epikote828EL" (bisphenol A type epoxy resin); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resin); and Mitsubishi Chemical's "jER152" (phenolic varnish type epoxy resin). Chemical Company's "630", "630LSD", and "604" (glycidylamine type epoxy resin); ADEKA Company's "ED-523T" (glycyrrhizol type epoxy resin); ADEKA Company's "EP-3950L" and "EP-3980S" (glycidylamine type epoxy resin); ADEKA Company's "EP-4088S" (dicyclopentadiene type epoxy resin); NIPPON STEEL Chemical & Material Company's "ZX-1059" (a mixture of bisphenol A and bisphenol F type epoxy resins); nagase Chemtex's "EX-721" (glycidyl ester type epoxy resin); Daicel's "CELLOXID2021P" (alicyclic epoxy resin with an ester skeleton); 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 type epoxy resin), etc. These can be used alone or in combination with two or more types.

[0028] Solid epoxy resin, preferably a solid epoxy resin having three or more epoxy groups in one molecule, more preferably an aromatic solid epoxy resin having three or more epoxy groups in one molecule.

[0029] Solid epoxy resins are preferably bis(xylenol) type epoxy resins, naphthalene type epoxy resins, naphthalene type tetrafunctional epoxy resins, naphthol phenolic varnish type epoxy resins, cresol phenolic varnish type epoxy resins, dicyclopentadiene type epoxy resins, triphenol 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 phenolphthalein imine type epoxy resins.

[0030] Specific examples of solid epoxy resins include: DIC's "HP4032H" (naphthalene-type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene-type tetrafunctional epoxy resins); DIC's "N-690" (cresol phenolic varnish epoxy resin); DIC's "N-695" (cresol phenolic varnish epoxy resin); DIC's "HP-7200," "HP-7200HH," "HP-7200H," and "HP-7200L" (dicyclopentadiene-type epoxy resins); and DIC's "EXA-73." 11”, “EXA-7311-G3”, “EXA-7311-G4”, “EXA-7311-G4S”, “HP6000”, “HP6000L” (naphthyl ether type epoxy resin); “EPPN-502H” (triphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; “NC7000L” (naphthol phenolic varnish type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; “NC3000H”, “NC3000”, “NC3000L”, “NC3000FH”, “NC3100” (biphenyl type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; NIPPON STEEL Chemical & Material's "ESN475V" and "ESN4100V" (naphthalene-type epoxy resin); NIPPON STEEL Chemical & Material's "ESN485" (naphthol-type epoxy resin); NIPPON STEEL Chemical & Material's "ESN375" (dihydroxynaphthalene-type epoxy resin); Mitsubishi Chemical's "YX4000H," "YX4000," "YX4000HK," and "YL7890" (bis(xylenol)-type epoxy resin); Mitsubishi Chemical's "YL6121" (biphenyl-type epoxy resin); Mitsubishi Chemical's "YX8800" (anthracite-type epoxy resin); Mitsubishi Chemical Company's "YX7700" (phenolic aryl type epoxy resin); Osaka Gas Chemical Company's "PG-100" and "CG-500"; Mitsubishi Chemical Company's "YL7760" (bisphenol AF type epoxy resin); Mitsubishi Chemical Company's "YL7800" (bisphenol A type epoxy resin); Mitsubishi Chemical Company's "jER1010" (bisphenol A type epoxy resin); Mitsubishi Chemical Company's "jER1031S" (tetraphenylethane type epoxy resin);Nippon Kayaku Co., Ltd. manufactures "WHR991S" (phenolphthalein-type epoxy resin), etc. These can be used alone or in combination with two or more other types.

[0031] When a combination of liquid epoxy resin and solid epoxy resin is used as an epoxy resin, the mass ratio of them (liquid epoxy resin: solid epoxy resin) is preferably 20:1 to 1:10, more preferably 10:1 to 1:5, and even more preferably 5:1 to 1:2.

[0032] (A-1) The epoxy equivalent of the 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. Epoxy equivalent represents the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be determined according to JIS K7236.

[0033] (A-1) The weight-average molecular weight (Mw) of the epoxy resin is preferably 100~5,000, more preferably 250~3,000, and even more preferably 400~1,500. The weight-average molecular weight of the resin can be determined by gel permeation chromatography (GPC) using a polystyrene equivalent.

[0034] The amount of epoxy resin (A-1) in the resin composition is, relative to 100% by mass of the non-volatile components in the resin composition, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 4% by mass or more, 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 epoxy resin (A-1) is within the aforementioned range, the light transmittance of the cured resin composition layer can be effectively improved. Furthermore, it is preferable to suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the cured resin composition layer, and improve adhesion.

[0035] The amount of epoxy resin (A-1) in the resin composition is, relative to 100% by mass of the resin component of the resin composition, preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 15% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and particularly preferably 50% by mass or less. The resin component of the resin composition refers to, without particular limitation, the component remaining after removing the inorganic filler (B) from the non-volatile components of the resin composition. When the amount of epoxy resin (A-1) is within the aforementioned range, it can effectively improve the light transmittance of the hardened resin composition layer. Furthermore, it is preferable to suppress the viscosity of the resin composition layer, reduce its melt viscosity, suppress the elastic modulus of the hardened resin composition layer, and improve adhesion.

[0036] The ratio "W(A-1) / {W(B)×S(B)}" is obtained by dividing the mass W(A-1) of the (A-1) epoxy resin in the resin composition by the product of the mass W(B) of the (B) inorganic filler in the resin composition and the specific surface area S(B). This ratio "W(A-1) / {W(B)×S(B)}" is equivalent to the amount of (A-1) epoxy resin per unit surface area of ​​the (B) inorganic filler. The ratio "W(A-1) / {W(B)×S(B)}" significantly achieves the desired effect of the present invention. Preferably, it is 0.1×10⁻³ g / m² or more, more preferably 1.0×10⁻³ g / m² or more, particularly preferably 2.0×10⁻³ g / m² or more, more preferably 22×10⁻³ g / m² or less, more preferably 18×10⁻³ g / m² or less, and particularly preferably 16×10⁻³ g / m² or less.

[0037] [3.2. (A-2) Phenolic Resin] (A) A thermosetting resin, preferably containing (A-2) phenolic resin as component (A-2). The phenolic resin can be a compound having one or more, preferably two or more, phenolic hydroxyl groups per molecule. Phenolic hydroxyl groups refer to hydroxyl groups bonded to aromatic rings such as benzene rings and naphthalene rings. In particular, (A-2) phenolic resin is preferably used in combination with (A-1) epoxy resin. When (A-1) epoxy resin and (A-2) phenolic resin are used in combination, (A-2) phenolic resin reacts with (A-1) epoxy resin, thus functioning as a curing agent to harden the resin composition.

[0038] From the viewpoint of heat resistance and water resistance, (A-2) phenolic resin is preferably a phenolic resin with a phenolic varnish structure. Furthermore, from the viewpoint of adhesion, a nitrogen-containing phenolic resin is preferred, and more preferably a phenolic resin containing a triazine skeleton. Among these, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion, a phenolic varnish resin containing a triazine skeleton is preferred.

[0039] (A-2) Specific examples of phenolic resins include, for example, "MEH-7700", "MEH-7810", "MEH-7851", and "MEH-8000" manufactured by Meiwa Chemical Co., Ltd.; "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and NIPPON STEEL Chemical &... Material Co., Ltd. manufactures "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", "SN-495", "SN-375", "SN-395", DIC Co., Ltd. manufactures "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", "KA-1165", and Chung Jung Chemical Co., Ltd. manufactures "GDP-6115L" and "GDP-6115H", etc.

[0040] (A-2) Phenolic resins can be used alone or in combination with two or more types.

[0041] (A-2) The hydroxyl equivalent of the 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 most preferably 100 g / eq. to 300 g / eq. The hydroxyl equivalent represents the mass of resin in one hydroxyl equivalent.

[0042] When the number of epoxy groups in (A-1) the epoxy resin is set to 1, the number of hydroxyl groups in (A-2) the phenolic resin is preferably 0.01 or more, more preferably 0.10 or more, even more preferably 0.15 or more, preferably 5.0 or less, more preferably 2.0 or less, and particularly preferably 1.0 or less. "The number of epoxy groups in (A-1) the epoxy resin" represents the sum of all values ​​obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. Similarly, "the number of hydroxyl groups in (A-2) the phenolic resin" represents the sum of all values ​​obtained by dividing the mass of the non-volatile components of the phenolic resin present in the resin composition by the hydroxyl equivalent.

[0043] The amount of (A-2) phenolic resin in the resin composition is, relative to 100% by mass of the non-volatile components in the resin composition, preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 0.5% by mass or more, 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 (A-2) phenolic resin is within the aforementioned range, it can effectively improve the light transmittance of the hardened resin composition layer. Furthermore, it is preferable to suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the hardened resin composition layer, and improve adhesion.

[0044] The amount of (A-2)phenolic resin in the resin composition is, relative to 100% by mass of the resin content of the resin composition, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, 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 the aforementioned range, the light transmittance of the hardened resin composition layer can be effectively improved. Furthermore, it is preferable to suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the hardened resin composition layer, and improve adhesion.

[0045] The ratio W(A-2) / W(B) of the mass of (A-2) phenolic resin in the resin composition to the mass of (B) inorganic filler in the resin composition, W(A-2) / W(B), is preferred to significantly achieve the desired effect of the present invention within a specific range. Specifically, the aforementioned ratio W(A-2) / W(B) is preferably 0.1 × 10⁻² or more, more preferably 0.5 × 10⁻² or more, particularly preferably 1.0 × 10⁻² or more, preferably 20.0 × 10⁻² or less, more preferably 15.0 × 10⁻² or less, and particularly preferably 10.0 × 10⁻² or less.

[0046] The ratio "W(A-2) / {W(B)×S(B)}" is obtained by dividing the mass W(A-2) of the (A-2) phenolic resin in the resin composition by the product of the mass W(B) of the (B) inorganic filler in the resin composition and the specific surface area S(B). This ratio "W(A-2) / {W(B)×S(B)}" represents the amount of (A-2) phenolic resin per unit surface area of ​​the (B) inorganic filler. From the viewpoint that this ratio "W(A-2) / {W(B)×S(B)}" significantly yields the desired effect of the present invention, it is preferably 0.5×10⁻³ g / m² or more, more preferably 1.0×10⁻³ g / m² or more, particularly preferably 2.0×10⁻³ g / m² or more, preferably 10×10⁻³ g / m² or less, more preferably 8.0×10⁻³ g / m² or less, and particularly preferably 6.0×10⁻³ g / m² or less.

[0047] [3.3.(A-3) Reactive Ester Resin] (A) The thermosetting resin system includes (A-3) reactive ester resin as component (A-3). The (A-3) reactive ester resin is preferably a compound with two or more highly reactive ester groups in one molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, or heterocyclic hydroxyl compounds. In particular, the (A-3) reactive ester resin is preferably used in combination with the (A-1) epoxy resin. When the (A-1) epoxy resin and the (A-3) reactive ester resin are used in combination, the (A-3) reactive ester resin functions as a curing agent that reacts with the (A-1) epoxy resin to harden the resin composition.

[0048] (A-3) The reactive ester resin is preferably obtained by the condensation reaction of a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxyl compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, the reactive ester resin obtained from a carboxylic acid compound and a hydroxyl compound is preferred, and the reactive ester resin obtained from a carboxylic acid compound and a phenolic compound and / or a naphthol compound is even more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, edaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Phenolic or naphthol compounds include, for example, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthol, 1,6-dihydroxynaphthol, 2,6-dihydroxynaphthol, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzotriol, dicyclopentadiene-type diphenol compounds, phenolic varnishes, etc. Here, "dicyclopentadiene-type diphenol compounds" refers to diphenol compounds obtained by the condensation of one molecule of dicyclopentadiene and two molecules of phenol.

[0049] Specifically, (A-3) the reactive ester resin is preferably a dicyclopentadiene-type reactive ester resin, a naphthalene-type reactive ester resin containing a naphthalene structure, an acetylene-containing reactive ester resin for phenolic varnishes, or a benzoylene-containing reactive ester resin for phenolic varnishes. More preferably, it is selected from at least one of a dicyclopentadiene-type reactive ester resin and a naphthalene-type reactive ester resin. The dicyclopentadiene-type reactive ester resin is preferably an reactive ester resin containing a dicyclopentadiene-type diphenol structure.

[0050] (A-3) Commercially available reactive ester resins, such as reactive ester resins containing a dicyclopentadiene-type bisphenol structure, include "EXB9451", "EXB9460", "EXB9460S", "EXB-8000L", "EXB-8000L-65M", "EXB-8000L-65TM", "HPC-8000L-65TM", "HPC-8000", "HPC-8000-65T", "HPC-8000H", and "HPC-8000H-65TM" (manufactured by DIC Corporation); reactive ester resins containing a naphthalene structure... Examples of reactive ester resins include "HP-B-8151-62T", "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", "HPC-8150-62T", and "EXB-8" (manufactured by DIC Corporation); examples of phosphorus-containing reactive ester resins include "EXB9401" (manufactured by DIC Corporation); examples of acetylated reactive ester resins for phenolic varnishes include "DC808" (Mitsubishi). (Made by Chemical Company); reactive ester resins containing benzyl groups in phenolic varnishes, such as "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Company); reactive ester resins containing styrene and naphthalene structures, such as "PC1300-02-65MA" (manufactured by AIR WATER Company), etc.

[0051] (A-3) One type of active ester resin can be used alone, or two or more types can be used in combination.

[0052] (A-3) The active ester group equivalent of the 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 indicates the mass of resin containing 1 active ester group equivalent.

[0053] When the number of epoxy groups in the epoxy resin (A-1) is set to 1, the number of active ester groups in the active ester resin (A-3) is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.10 or more, 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" represents the sum of all values ​​obtained by dividing the mass of the non-volatile components of the active ester resin present in the resin composition by the equivalent amount of active ester groups.

[0054] The amount of (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, more preferably 10% by mass or less, more preferably 5% by mass or less, and particularly preferably 2% by mass or less, relative to 100% by mass of the non-volatile components in the resin composition. When the amount of (A-3) active ester resin is within the aforementioned range, the desired effects of the present invention can be significantly obtained.

[0055] The amount of (A-3) active ester resin in the resin composition is, relative to 100% by mass of the resin component in the resin composition, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 3% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less. When the amount of (A-3) active ester resin is within the aforementioned range, the desired effects of the present invention can be significantly obtained.

[0056] [3.4.(A-4) Maleimide Resin] (A) A thermosetting resin, preferably a (A-4) maleimide resin as component (A-4). The maleimide resin can be a compound containing at least one, preferably two or more, maleimide groups (2,5-dihydro-2,5-dioxo-1H-pyrrole-1-yl) in one molecule. The (A-4) maleimide resin exhibits free radical polymerization due to the vinyl double bond contained in the maleimide group. Furthermore, the (A-4) maleimide resin can react with the (A-1) epoxy resin in the presence of a suitable catalyst such as an imidazole compound. Therefore, the (A-4) maleimide resin can thermoset the resin composition through such reactions.

[0057] (A-4) Maleimide resin may be an aliphatic maleimide resin containing an aliphatic amine skeleton, or an aromatic maleimide resin containing an aromatic amine skeleton, or a combination thereof. Furthermore, (A-4) maleimide resin may be used alone or in combination with two or more types.

[0058] (A-4) Maleimide resins, for example, include "SLK-2600" manufactured by Shin-Etsu Chemical Co., Ltd., "BMI-1500", "BMI-1700", "BMI-689", "BMI-2500" (maleimide compounds containing dimer diamine structures) manufactured by Designer Molecules Co., Ltd., "BMI-6100" (aromatic maleimide compounds) manufactured by Designer Molecules Co., Ltd., "MIR-5000-60T" and "MIR-3000-70MT" (biphenyl aralkyl type maleimide compounds) manufactured by Nippon Kayaku Co., Ltd., "BMI-70" and "BMI-80" manufactured by Ki-Chemica Co., Ltd., and "BMI-2300" and "BMI-TMH" manufactured by Yamato Chemical Co., Ltd. Furthermore, (A-4) maleimide resins, for example, the maleimide resin disclosed in Patent Application Publication No. 2020-500211 (a maleimide compound containing an indane ring skeleton).

[0059] The amount of (A-4) maleimide resin in the resin composition is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, particularly preferably 2.0% by mass or more, more preferably 20% by mass or less, more preferably 15% by mass or less, and particularly preferably 10% by mass or less, relative to 100% by mass of the non-volatile components in the resin composition. When the amount of (A-4) maleimide resin is within the aforementioned range, the desired effects of the present invention can be significantly obtained.

[0060] The amount of (A-4) maleimide resin in the resin composition is, relative to 100% by mass of the resin content of the resin composition, preferably 1% by mass or more, more preferably 4% by mass or more, particularly preferably 6% by mass or more, 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 (A-4) maleimide resin is within the aforementioned range, the desired effects of the present invention can be significantly obtained.

[0061] The ratio W(A-4) / W(B) of the mass of maleimide resin (A-4) in the resin composition to the mass of inorganic filler (B) in the resin composition, W(A-4) / W(B), significantly yields the desired effect of the present invention, and is preferably within a specific range. Specifically, the aforementioned ratio W(A-4) / W(B) is preferably 0.1 × 10⁻² or more, more preferably 1.0 × 10⁻² or more, even more preferably 2.0 × 10⁻² or more, particularly preferably 3.1 × 10⁻² or more, preferably 30 × 10⁻² or less, more preferably 20 × 10⁻² or less, and particularly preferably 15 × 10⁻² or less.

[0062] Consider the ratio "W(A-4) / {W(B)×S(B)}" obtained by dividing the mass W(A-4) of the (A-4) maleimide resin in the resin composition by the product of the mass W(B) of the (B) inorganic filler in the resin composition and the specific surface area S(B). This ratio "W(A-4) / {W(B)×S(B)}" corresponds to the amount of (A-4) maleimide resin per unit surface area of ​​the (B) inorganic filler. The view that the ratio "W(A-4) / {W(B)×S(B)}" significantly achieves the desired effect of the present invention is preferably 0.5×10⁻³ g / m² or more, more preferably 1.0×10⁻³ g / m² or more, particularly preferably 1.5×10⁻³ g / m² or more, preferably 20×10⁻³ g / m² or less, more preferably 15×10⁻³ g / m² or less, and particularly preferably 11×10⁻³ g / m² or less.

[0063] [3.5. Other thermosetting resins] (A) Other examples of thermosetting resins include cyanate ester resins, carbodiimide resins, acid anhydride resins, amine resins, benzoxazine resins, and thiol resins. When these resins are used in combination with epoxy resin (A-1), they react with the epoxy resin (A-1) to act as a curing agent, thus hardening the resin composition. Furthermore, another example of thermosetting resins (A) includes free radical polymerizable resins other than maleimide resins (A-4). These free radical polymerizable resins generally possess vinyl unsaturated bonds and can be cured by free radical polymerization. Examples of free radical polymerizable resins include, for instance, styrene-based free radical polymerizable resins having one or more vinyl groups directly bonded to aromatic carbon atoms, and allyl-based free radical polymerizable resins having one or more allyl groups. These resins can be used alone or in combination of two or more types.

[0064] The resin comprises components (A-1) to (A-4) above. The number average molecular weight (Mn) of the thermosetting resin (A) is preferably less than 3,000, more preferably less than 2,000, and even more preferably less than 1,500, preferably more than 100, more preferably more than 250, and even more preferably more than 400. The number average molecular weight of the resin can be determined by gel permeation chromatography (GPC) using a value converted from polystyrene.

[0065] [3.6.(A) Amount of thermosetting resin] The amount of thermosetting resin (A) in the resin composition is, relative to 100% by mass of the non-volatile components in the resin composition, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 5% by mass or more, 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 thermosetting resin (A) is within the aforementioned range, the light transmittance of the cured resin composition layer can be effectively improved. Furthermore, it is preferable to suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the cured resin composition layer, and improve adhesion.

[0066] The amount of thermosetting resin (A) in the resin composition is, relative to 100% by mass of the resin content of the resin composition, preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, 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 thermosetting resin (A) is within the aforementioned range, the light transmittance of the cured resin composition layer can be effectively improved. Furthermore, it generally suppresses the viscosity of the resin composition layer, reduces the melt viscosity, suppresses the elastic modulus of the cured resin composition layer, and improves adhesion.

[0067] [4.(B) Inorganic filler] The resin composition contains inorganic filler (B) as component (B). Inorganic filler (B) is typically contained in the resin composition in the form of particles. Furthermore, this inorganic filler (B) has a specific range of specific surface areas.

[0068] (B) The specific surface area of ​​the inorganic filler is typically 3.0 m² / g or more, preferably 3.5 m² / g or more, even more preferably 4.0 m² / g or more, 5.0 m² / g or more, 10.0 m² / g or more, or 20.0 m² / g or more. When the inorganic filler (B) contained in the resin composition has a specific surface area within the aforementioned range, the light transmittance of the hardened resin composition layer can be improved. Further, it is preferable to suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the hardened resin composition layer, and improve adhesion. (B) The upper limit of the specific surface area of ​​the inorganic filler material is preferably 100 m² / g or less, more preferably 70 m² / g or less, even more preferably 50 m² / g or less, and most preferably 40 m² / g or less, so as to achieve the desired effect of the present invention.

[0069] (B) The specific surface area of ​​inorganic fillers is determined by the BET method using a specific surface area measuring device (Macsorb HM-1210 manufactured by MOUNTECH). Nitrogen gas is adsorbed onto the surface of the sample, and the specific surface area can be calculated by using the BET multi-point method.

[0070] (B) The inorganic filler material is made of inorganic compounds. Examples of inorganic filler materials include, for example, silicon dioxide, alumina, glass, violet, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, gibbsite, 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 zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium phosphotungstenate. Among these, silicon dioxide and alumina are preferred, with silicon dioxide being particularly preferred. Examples of silicon dioxide include, for example, amorphous silicon dioxide, fused silicon dioxide, crystalline silicon dioxide, synthetic silicon dioxide, and hollow silicon dioxide. Furthermore, spherical silicon dioxide is preferred as the silicon dioxide. (B) Inorganic filler materials can be used alone or in combination of two or more types.

[0071] (B) The average particle size of the inorganic filler is preferably 1.5 μm or less, more preferably 1.0 μm or less, even more preferably 0.6 μm or less, particularly preferably 0.4 μm or less, preferably 0.01 μm or more, and even more preferably 0.05 μm or more. (B) When the average particle size of the inorganic filler is within the aforementioned range, the light transmittance of the hardened resin composition layer is effectively improved. Furthermore, it can generally suppress the viscosity of the resin composition layer, reduce the melt viscosity, suppress the elastic modulus of the hardened resin composition layer, and improve adhesion.

[0072] (B) The average particle size of inorganic fillers can be determined using laser diffraction and scattering based on Mie scattering theory. Specifically, using a laser diffraction and scattering particle size distribution measuring device, the particle size distribution of the inorganic filler is prepared on a volume basis, and the median particle size can be used as the average particle size for measurement. The sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a small glass bottle and ultrasonically dispersing them for 10 minutes. Using a laser diffraction particle size distribution measuring device with blue and red light source wavelengths, the particle size distribution of the inorganic filler on a volume basis is measured using a flow cell method. The average particle size is calculated from the median particle size of the obtained particle size distribution. Examples of laser diffraction particle size distribution measuring devices include the "LA-960" manufactured by Horiba Manufacturing Co., Ltd.

[0073] (B) From the perspective of improving the moisture resistance and dispersibility of inorganic fillers, surface treatment is preferable. Examples of surface treatment agents include fluorinated silane coupling agents, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, alkoxysilanes, organosilazane compounds, and titanate coupling agents. A single type of surface treatment agent can be used alone, or two or more types can be combined in any combination.

[0074] Commercially available surface treatment agents include, for example, "KBM403" (3-epoxypropoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., "KBM-4803" (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical Industry Co., Ltd., and "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Industry Co., Ltd., etc.

[0075] From the perspective of improving the dispersibility of (B) inorganic fillers by varying the degree of surface treatment with the surface treatment agent, it is preferable to contain them within a specific range. 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.

[0076] The degree of surface treatment by the surface treatment agent can be evaluated by the carbon content per unit surface area of ​​the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the carbon content per unit surface area is preferably 0.02 mg / m² or more, more preferably 0.1 mg / m² or more, and even more preferably 0.2 mg / m² or more. Furthermore, from the viewpoint of suppressing the increase in the melt viscosity of the resin composition, it is preferably 1.0 mg / m² or less, more preferably 0.8 mg / m² or less, and even more preferably 0.5 mg / m² or less.

[0077] (B) The carbon content per unit surface area of ​​inorganic fillers can be determined by washing the surface-treated inorganic fillers with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK is added to the surface-treated inorganic filler, and the mixture is ultrasonically washed at 25°C for 5 minutes. After removing the supernatant and drying the solid components, carbon analysis is used to determine the carbon content per unit surface area of ​​the inorganic filler. A carbon analyzer such as the "EMIA-320V" manufactured by Horiba Corporation can be used.

[0078] The amount of inorganic filler (B) in the resin composition is, relative to 100% by mass of the non-volatile components in the resin composition, preferably 40% by mass or more, more preferably 50% by mass or more, particularly preferably 60% by mass or more, 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 inorganic filler (B) is within the aforementioned range, the linear thermal expansion coefficient of the cured resin composition can be reduced, thus suppressing expansion and contraction caused by temperature changes, improving the dimensional stability of the solder resist layer, or suppressing the formation of cracks. Generally, the thicker the solder resist layer, the greater the tendency for expansion and contraction. Therefore, as mentioned above, reducing the linear thermal expansion coefficient of the cured material is more useful in addressing the problems that are prone to occur with thick solder resist layers.

[0079] [5. (C) Elastomers] The resin composition, in combination with components (A) to (B) above, may further include an elastomer (C) as an optional component. The elastomer (C) used as component (C) does not contain components equivalent to those in (A) to (B) above. When using a resin composition containing the elastomer (C), the elastic modulus of the cured material can be effectively suppressed, thus effectively suppressing warpage in printed circuit boards and semiconductor wafer packages with solder resist layers. This suppression of warpage is particularly useful in situations where the solder resist layer is thick or where there is a high amount of inorganic filler (B) in the resin composition, which generally makes warpage more likely.

[0080] (C) The elastomer is a resin with flexibility, preferably a resin with rubber elasticity or a resin polymerized with other components to exhibit rubber elasticity. Examples of resins with rubber elasticity include those that, according to Japanese Industrial Standard (JIS K7161), exhibit an elastic modulus of less than 1 GPa when subjected to a tensile test at 25°C and 40% RH. This (C) elastomer can be used alone or in any ratio of two or more types.

[0081] (C) The elastomer is preferably of high molecular weight. The number average molecular weight (Mn) of the elastomer is preferably 1,000 or higher, more preferably 1,500 or higher, even more preferably 2,000 or higher, even more preferably 3,000 or higher, and most preferably 5,000 or higher. The upper limit is preferably 1,000,000 or lower, and more preferably 900,000 or lower. The number average molecular weight (Mn) is the number average molecular weight converted from polystyrene determined using GPC (gel permeation chromatography).

[0082] (C) The elastomer is preferably selected from one or more resins with 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 the resin with 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 and is generally -15°C or higher. Furthermore, the resin that is liquid at 25°C is preferably liquid at 20°C or lower, more preferably liquid at 15°C or lower. The glass transition temperature can be determined by DSC (differential scanning calorimetry) at a heating rate of 5°C / min.

[0083] (C) An elastomer, preferably a resin having one or more structures selected from polybutadiene, polysiloxane, poly(meth)acrylate, polyalkylene, polyoxyalkylene, polyisoprene, polyisobutylene, polycarbonate, and polystyrene within its molecule. More preferably, it is a resin having one or two or more structures selected from polybutadiene, poly(meth)acrylate, polyoxyalkylene, polyisoprene, polyisobutylene, polycarbonate, and polystyrene. Furthermore, it is even more preferably a resin having one or more structures selected from polybutadiene and polyoxyalkylene, particularly preferably a resin having a polybutadiene structure. "(meth)acrylate" refers to methacrylates and acrylates, and combinations thereof. These structures may be contained in the main chain and also in the side chains.

[0084] (C) The elastomer may have functional groups that can react with the thermosetting resin of (A). When the elastomer of (C) reacts with the thermosetting resin of (A), the mechanical strength of the cured resin composition can be increased. The functional groups that can react with the thermosetting resin of (A) include functional groups that are manifested by heating. The functional groups that can react with the thermosetting resin of (A) are, for example, selected from one or more functional groups in the group consisting of hydroxyl, carboxyl, anhydride, phenolic hydroxyl, epoxy, isocyanate, carbamate and maleimide. Among them, the functional group is preferably hydroxyl, anhydride, phenolic hydroxyl, epoxy, isocyanate, carbamate and maleimide, more preferably hydroxyl, anhydride, phenolic hydroxyl, epoxy and maleimide, and particularly preferably phenolic hydroxyl and maleimide. However, the number-average molecular weight (Mn) of the (C) elastomer containing functional groups is preferably 3,000 or higher.

[0085] (C) Examples of elastomers include resins containing a polybutadiene structure. The polybutadiene structure can be contained in the main chain or in the side chains. The polybutadiene structure can be partially or completely hydrogenated. Resins containing a polybutadiene structure are sometimes called "polybutadiene resins". Specific examples of polybutadiene resins include: Cray Valley's "Ricon 130MA8", "Ricon 130MA13", "Ricon 130MA20", "Ricon 131MA5", "Ricon 131MA10", "Ricon 131MA17", "Ricon 131MA20", and "Ricon 184MA6" (polybutadiene containing anhydride groups); Nippon Soda's "GQ-1000" (polybutadiene with introduced hydroxyl and carboxyl groups), "G-1000", "G-2000", "G-3000" (polybutadiene with two-terminated hydroxyl groups), "GI-1000", "GI-2000", and "GI-3000" (hydrogenated polybutadiene with two-terminated hydroxyl groups); and Nagase. Examples of polybutadiene resins include "FCA-061L" (hydrogenated polybutadiene-backbone epoxy resin) manufactured by Chemtex. Specific examples of polybutadiene resins include linear polyimides (as described in Japanese Patent Application Publication No. 2006-37083 and International Publication No. 2008 / 153208) made from hydroxyl-terminated polybutadiene, diisocyanate compounds, and tetrabasic anhydrides, as well as butadiene containing phenolic hydroxyl groups. The butadiene content of this polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details regarding this polyimide resin, please refer to Japanese Patent Application Publication No. 2006-37083 and International Publication No. 2008 / 153208, which are included in this specification.

[0086] (C) Another example of an elastomer is a resin containing a poly(meth)acrylate structure. Resins containing a poly(meth)acrylate structure are sometimes called "poly(meth)acrylate resins". Examples of poly(meth)acrylate resins include teisanresin manufactured by Nagase Chemtex, ME-2000, W-116.3, W-197C, KG-25, and KG-3000 manufactured by Negami Kogyo Co., Ltd., and ARUFON UH-2000 manufactured by Toa Synthetic Co., Ltd.

[0087] (C) Another example of an elastomer is a resin containing a polycarbonate structure. Resins containing a polycarbonate structure are sometimes called "polycarbonate resins." Examples of polycarbonate resins include "FPC0220" and "FPC2136" manufactured by Mitsubishi Gas Chemical Co., Ltd., "T6002" and "T6001" (polycarbonate diol) manufactured by Asahi Kasei Chemicals Co., Ltd., and "C-1090," "C-2090," and "C-3090" (polycarbonate diol) manufactured by Kuraray Co., Ltd. Furthermore, linear polyimides made from hydroxyl-terminated polycarbonate, diisocyanate compounds, and tetrabasic anhydrides can also be used. The carbonate structure content of this polyimide resin is preferably 60% to 95% by mass, more preferably 75% to 85% by mass. For details regarding the polyimide resin, please refer to International Publication No. 2016 / 129541, which is incorporated herein by reference.

[0088] (C) Another example of elastomers is a resin containing a polysiloxane structure. Resins containing a polysiloxane structure are sometimes called "siloxane resins". Examples of siloxane resins include "SMP-2006", "SMP-2003PGMEA", and "SMP-5005PGMEA" manufactured by Shin-Etsu SILICONES, and linear polyimides made from amine-terminated polysiloxanes and tetrabasic anhydrides (International Publication No. 2010 / 053185, Japanese Patent Application Publication No. 2002-12667, and Japanese Patent Application Publication No. 2000-319386, etc.).

[0089] (C) Other examples of elastomers include resins containing polyalkylene or polyoxyalkylene hydroxyl structures. Resins containing polyalkylene structures are sometimes called "alkylene resins," and resins containing polyoxyalkylene hydroxyl structures are sometimes called "alkoxy resins." The number of carbon atoms in the polyalkylene and polyoxyalkylene hydroxyl structures is preferably 2 to 15, more preferably 3 to 10, and even more preferably 5 to 8. Specific examples of alkylene and alkoxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Corporation, and "BMI-3000" manufactured by Designer Molecules.

[0090] (C) Another example of an elastomer is a resin containing a polyisoprene structure. Resins containing a polyisoprene structure are sometimes called "isoprene resins". Specific examples of isoprene resins include "KL-610" and "KL613" manufactured by Kuraray.

[0091] (C) Another example of elastomers is resins containing a polyisobutylene structure. Resins containing a polyisobutylene structure are sometimes called "isobutylene resins". Specific examples of isobutylene resins include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer) manufactured by Kaneka Corporation.

[0092] (C) Another example of an elastomer may be a resin containing a polystyrene structure. Resins containing a polystyrene structure are sometimes called "styrene resins." Styrene resins may also be copolymers combining styrene units, including any repeating units different from the aforementioned styrene units, or hydrogenated polystyrene resins. Examples of styrene resins include styrene-butadiene-styrene block copolymers (SBS), styrene-isoprene-styrene block copolymers (SIS), styrene-ethylene-butene-styrene block copolymers (SEBS), styrene-ethylene-propylene-styrene block copolymers (SEPS), styrene-ethylene-ethylene-propylene-styrene block copolymers (SEEPS), styrene-butadiene-butene-styrene block copolymers (SBBS), styrene-butadiene diblock copolymers, hydrogenated styrene-butadiene block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-butadiene random copolymers, and styrene-maleic anhydride copolymers. Specific examples of styrene resins include hydrogenated styrene thermoplastic elastomers "H1041", "TAFTECH1043", "TAFTECP2000", and "TAFTECMP10" (manufactured by Asahi Kasei Corporation); epoxidized styrene-butadiene thermoplastic elastomers "EpofriendAT501" and "CT310" (manufactured by DAICL Corporation); hydroxyl-modified styrene elastomers "SEPTONHG252" (manufactured by Kuraray Corporation); and carboxyl-modified... Styrene-based elastomer "TAFTECN503M", amine-modified styrene-based elastomer "TAFTECN501", anhydride-modified styrene-based elastomer "TAFTECM1913" (manufactured by Asahi Kasei Chemicals); unmodified styrene-based elastomer "SEPTONS8104" (manufactured by Kuraray); styrene-ethylene / butene-styrene block copolymer "FG1924" (manufactured by Kraton) and "EF-40" (manufactured by CRAY VALLEY).

[0093] (C) The elastic system is miscible with resin components other than the (C) elastomer and is contained in the resin composition and its cured form. Generally, the examples described above are miscible with resin components such as (A) thermosetting resins. Alternatively, the (C) elastic system is immiscible with resin components other than the (C) elastomer and is contained in the resin composition and its cured form in particulate form. Such particulate (C) elastomers generally function as organic fillers. Particulate (C) elastomers typically perform the same functions as those miscible with resin components other than the (C) elastomer. Examples of particulate (C) elastomers include, for instance, "EXL2655" manufactured by Dow Chemical Japan, and "AC3401N" and "AC3816N" manufactured by AICA Industries.

[0094] (C) One type of elastomer may be used alone, or two or more types may be used in combination.

[0095] (C) The amount of elastomer is relative to 100% by mass of the non-volatile components in the resin composition, preferably 1% by mass or more, more preferably 2% by mass or more, particularly preferably 4% by mass or more, preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less. (C) When the amount of elastomer is within the aforementioned range, the minimum melt viscosity of the resin composition is reduced, which may effectively suppress the warpage of printed circuit boards and semiconductor wafer packages with solder resist layers.

[0096] (C) The amount of elastomer is, relative to 100% by mass of the resin component in the resin composition, preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. (C) When the amount of elastomer is within the aforementioned range, the minimum melt viscosity of the resin composition can be reduced, or warpage of printed circuit boards and semiconductor wafer packages with solder resist layers can be effectively suppressed.

[0097] [6. (D) Organic colorants] The resin composition, in combination with components (A) to (C) above, may further contain an organic colorant (D) as an optional component. This organic colorant (D) does not contain components equivalent to those in (A) to (C) above. Using a resin composition containing the organic colorant (D) allows the solder resist layer to exhibit the desired color.

[0098] (D) Organic colorant, which may be pigment, dye, or a combination thereof, preferably pigment. Pigment has high coloring power, thus enabling the solder resist layer to effectively display color.

[0099] When citing examples of pigments, examples of blue pigments include phthalocyanine pigments, anthraquinone pigments, and dioxazine pigments. Examples of yellow pigments include monoazo pigments, diazo pigments, condensed azo pigments, benzimidazolone pigments, isoindolinone pigments, and anthraquinone pigments. Examples of red pigments include monoazo pigments, diazo 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.

[0100] (D) Organic colorants can be used alone or in combination of two or more types.

[0101] (D) The amount of organic colorant is relative to 100% by mass of the non-volatile components in the resin composition, preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, particularly preferably 0.01% by mass or more, 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.

[0102] (D) The amount of organic colorant is relative to 100% by mass of the resin component in the resin composition, preferably 0.001% by mass or more, more preferably 0.01% by mass or more, particularly preferably 0.1% by mass or more, preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 1% by mass or less.

[0103] [7. (E) Thermoplastic resins] The resin composition system, in combination with components (A) to (D) above, may further contain thermoplastic resin (E) as an optional component. The thermoplastic resin (E) used as component (E) does not contain components equivalent to those in (A) to (D) above.

[0104] (E) Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polyimide resins, polyamide-imide resins, polyether-imide resins, polyurethane resins, polyether-urethane resins, polyphenylene ether resins, polyether ether ketone resins, and polyester resins, with phenoxy resins being preferred. (E) A single type of thermoplastic resin may be used alone, or two or more types may be used in combination.

[0105] Examples of phenoxy resins include those having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenol acetophenone, phenolic varnish, biphenyl, fenestrated, dicyclopentadiene, norcamphene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The terminal group of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A single phenoxy resin may be used alone, or two or more may be used in combination. Specific examples of phenoxy resins include Mitsubishi Chemical's "1256" and "4250" (both phenoxy resins containing a bisphenol A backbone), "YX8100" (a phenoxy resin containing a bisphenol S backbone), and "YX6954" (a phenoxy resin containing a bisphenol acetophenone backbone). Other examples include NIPPON STEEL Chemical & Material's "FX280" and "FX293", Mitsubishi Chemical's "YL7500BH30", "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30", "YL6794", "YL7213", "YL7290", and "YL7482", etc.

[0106] Polyvinyl alcohol acetal resin, such as polyvinyl alcohol formaldehyde resin and polyvinyl alcohol butyral resin, is preferred. Specific examples of polyvinyl alcohol acetal resin 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 the S-Lec BH series, BX series (e.g., BX-5Z), KS series (e.g., KS-1), BL series, and BM series manufactured by Sekisui Chemicals Co., Ltd.

[0107] Specific examples of polyimide resins include "Rikacoat SN20" and "Rikacoat PN20" manufactured by Shin Nippon Rikan Co., Ltd.

[0108] Specific examples of polyamide-imide resins include "VylomaxHR11NN" and "VylomaxHR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamide-imide resins include modified polyamides such as "KS9100" and "KS9300" (polyamide-imide containing a polysiloxane backbone) manufactured by Hitachi Chemical Industries Co., Ltd.

[0109] Specific examples of polyether ether resins include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyphenylene ether resins include "OPE-2St 1200" oligomeric polyphenylene ether / styrene resin manufactured by Mitsubishi Gas Chemical Co., Ltd. Specific examples of polyether ether ketone resins include "Sumiploy K" manufactured by Sumitomo Chemical Co., Ltd. Specific examples of polyetherimide resins include "ULTEM" manufactured by GE.

[0110] Specific examples of polyurethane resins include "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

[0111] Polyolefin resins include, for example, low-density polyethylene, ultra-low-density polyethylene, high-density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, and other ethylene-based copolymer resins.

[0112] Examples of polyester resins include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene terephthalate resin, polypropylene terephthalate resin, polypropylene naphthalate resin, and polycyclohexyl terephthalate resin.

[0113] (E) The weight average molecular weight (Mw) of the thermoplastic resin is preferably greater than 5,000, more preferably greater than 8,000, even more preferably greater than 10,000, particularly preferably greater than 20,000, preferably less than 100,000, more preferably less than 70,000, even more preferably less than 60,000, and particularly preferably less than 50,000.

[0114] (E) The amount of thermoplastic resin is relative to 100% by mass of the non-volatile components in the resin composition, preferably 0.1% by mass or more, more preferably 0.5% by mass or more, particularly preferably 1.0% by mass or more, preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less.

[0115] (E) The amount of thermoplastic resin is relative to 100% by mass of the resin component in the resin composition, preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less.

[0116] [8. (F) Hardening accelerator] The resin composition system, in combination with components (A) to (E) above, may further contain a curing accelerator (F) as an optional component. The curing accelerator (F) does not contain components equivalent to (A) to (E) above. The curing accelerator (F) functions as a curing catalyst that promotes the curing of the (A-1) epoxy resin.

[0117] (F) Curing accelerators, such as 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, are examples. Among these, imidazole-based curing accelerators are preferred. (F) A single type of curing accelerator may be used alone, or two or more types may be used in combination.

[0118] Phosphorus-based hardening accelerators include, for example, aliphatic phosphonium salts such as tetrabutylphosphonium bromide, tetrabutylphosphonium chloride, tetrabutylphosphonium acetate, tetrabutylphosphonium decanoate, tetrabutylphosphonium laurate, bis(tetrabutylphosphonium)pyromellitic ester, tetrabutylphosphonium hexahydrophthalate, tetrabutylphosphonium 2,6-bis[(2-hydroxy-5-methylphenyl)methyl]-4-methylphenyloxide (Phenolate), and di-tert-butyldimethylphosphonium tetraphenylborate; methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, propyltriphenylphosphonium bromide, butyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium bromide, and p-tolyltriphenylphosphonium bromide. Aromatic phosphonium salts of phenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetrap-tolylborate, triphenylethylphosphonium tetraphenylborate, tri(3-methylphenyl)ethylphosphonium tetraphenylborate, tri(2-methoxyphenyl)ethylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc.; aromatic phosphine-borane complexes of triphenylphosphine-triphenylborane, etc.; aromatic phosphine-quinone addition reactants of triphenylphosphine-p-benzoquinone addition reactants, etc.; tributylphosphine, tri-tert-butylphosphine, trioctylphosphine, di-tert-butylphosphine, etc. Aliphatic phosphines such as t-butyl(2-butenyl)phosphine, di-tert-butyl(3-methyl-2-butenyl)phosphine, and tricyclohexylphosphine; and tributylphenylphosphine, di-tert-butylphenylphosphine, methyldiphenylphosphine, ethyldiphenylphosphine, butyldiphenylphosphine, diphenylcyclohexylphosphine, triphenylphosphine, tri-o-tolylphosphine, tri-m-tolylphosphine, tri-p-tolylphosphine, tri(4-ethylphenyl)phosphine, tri(4-propylphenyl)phosphine, tri(4-isopropylphenyl)phosphine, tri(4-butylphenyl)phosphine, tri(4-tert-butylphenyl)phosphine, tri(2,4-dimethylphenyl)phosphine, and tri(2,5-dimethylphenyl)phosphine. Aromatic phosphines such as tris(2,6-dimethylphenyl)phosphine, 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.

[0119] Urea is a type of hardening accelerator, and examples include aliphatic dimethylureas such as 1,1-dimethylurea; 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 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-epenylphenyl)bis(N',N'-dimethylurea), N,N-(4-methyl-1,3-epenylphenyl)bis(N',N'-dimethylurea)[toluenebisdimethylurea], etc.

[0120] Guanidine-based hardening accelerators include, for example, 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-methylbiguanidine, 1-ethylbiguanidine, 1-n-butylbiguanidine, 1-n-octadecylbiguanidine, 1,1-dimethylbiguanidine, 1,1-diethylbiguanidine, 1-cyclohexylbiguanidine, 1-allylbiguanidine, 1-phenylbiguanidine, 1-(o-tolyl)biguanidine, etc.

[0121] Imidazole-based hardening accelerators include, for example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole ontium trimellitate, 1-cyanoethyl-2-phenylimidazole ontium trimellitate, and 2,4-diamino-6-[2'-methylimidazole-(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-phenylimidazolyl isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazolium, 2-phenyl-4-methyl-5-hydroxymethylimidazolium, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline and other imidazole compounds and adducts of imidazole compounds with epoxy resins. Commercially available imidazole hardening accelerators include, for example, those manufactured by Shikoku Chemical Industry Co., Ltd. such as "1B2PZ", "2E4MZ", "2MZA-PW", "2MZ-OK", "2MA-OK", "2MA-OK-PW", "2PHZ", "2PHZ-PW", "Cl1Z", "Cl1Z-CN", "Cl1Z-CNS", and "C11Z-A"; and "P200-H50" manufactured by Mitsubishi Chemical Co., Ltd.

[0122] Metal-based hardening 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 organocobalt complexes such as acetoacetone cobalt(II) and acetoacetone cobalt(III), organocopper complexes such as acetoacetone copper(II), organozinc complexes such as acetoacetone zinc(II), organoiron complexes such as acetoacetone iron(III), organonickel complexes such as acetoacetone nickel(II), and organomanganese complexes such as acetoacetone manganese(II). Organometallic salts include examples such as zinc octanoate, tin octanoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0123] Amine-based curing accelerators include, for example, trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. Commercially available amine-based curing accelerators are also available, such as "MY-25" manufactured by ajinomoto-fine-techno.

[0124] The amount of (F) curing accelerator in the resin composition is, relative to 100% by mass of the non-volatile components in the resin composition, preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.03% by mass or more, preferably 1.0% by mass or less, more preferably 0.5% by mass or less, and particularly preferably 0.1% by mass or less.

[0125] The amount of (F) curing accelerator in the resin composition is, relative to 100% by mass of the resin component in the resin composition, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, particularly preferably 0.10% by mass or more, preferably 2.0% by mass or less, more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less.

[0126] [9. (G) Any additives] The resin composition system, in combination with the components (A) to (F) above, may further contain any additive (G) as any non-volatile component. Examples of any additive (G) include, for instance, free radical polymerization initiators such as peroxide-based free radical polymerization initiators and azo-based free 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 polysiloxane-based leveling agents and acrylic polymer-based leveling agents; tackifiers such as Benton and microcrystalline kaolinite; defoamers such as polysiloxane-based defoamers, acrylic defoamers, fluorinated defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion enhancers such as ureasilane; and triazole-based adhesion promoters, tetraazole-based adhesion promoters, and triazine-based adhesion promoters. Adhesion enhancers; antioxidants such as hindered phenolic antioxidants; fluorescent whitening agents such as zirconia derivatives; surfactants such as fluorine-based surfactants and polysiloxane-based surfactants; flame retardants such as phosphorus-based flame retardants (e.g., phosphate ester compounds, phosphazene compounds, phosphonic acid compounds, red phosphorus), nitrogen-based flame retardants (e.g., melamine sulfate), halogen-based flame retardants, and inorganic flame retardants (e.g., antimony trioxide); dispersants such as phosphate ester-based dispersants, polyoxyethylene-based dispersants, acetylene-based dispersants, polysiloxane-based dispersants, anionic dispersants, and cationic dispersants; 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) Any additive may be used alone or in combination of two or more types.

[0127] [10. The amount of resin containing nitrogen atoms in the resin composition] From the viewpoint of improving the adhesion of the solder resist layer, the resin components of (A) and (C) to (G) mentioned above are preferably resin components containing nitrogen atoms. In particular, when one or more of (A) thermosetting resin, (C) elastomer, (E) thermoplastic resin and (F) curing accelerator are resin components containing nitrogen atoms, the adhesion effect can be improved.

[0128] The amount of the resin component containing nitrogen atoms is relative to 100% by mass of the non-volatile components in the resin composition, preferably 0.1% by mass or more, more preferably 1.0% by mass or more, particularly preferably 2.0% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and particularly preferably 30% by mass or less.

[0129] Furthermore, the amount of resin component containing nitrogen atoms is, relative to 100% by mass of the resin component in the resin composition, preferably 5% by mass or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, and may also be 50% by mass or more. The upper limit is preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 75% by mass or less.

[0130] [11. (H) Solvent] The resin composition system, combined with the non-volatile components of components (A) to (G) above, may further contain solvent (H) as an arbitrary volatile component. Organic solvents are typically used as solvent (H). Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, and anisole; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; and 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diethylene glycol acetate, γ-butyrolactone, and methyl methoxypropionate. Ether-ester 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); acetylamine solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; urethane 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. (H) One type of solvent may be used alone, or two or more types may be used in combination.

[0131] (H) The amount of solvent is not particularly limited. When the total component in the resin composition is set to 100% by mass, it can be less than 60% by mass, less than 40% by mass, less than 30% by mass, less than 20% by mass, less than 15% by mass, less than 10% by mass, etc., or it can be 0% by mass.

[0132] [12. Method for manufacturing resin composition] Resin compositions can be manufactured, for example, by mixing the above-mentioned components. These components can be mixed partially or entirely simultaneously, or sequentially. During the mixing process, a suitable temperature can be set, allowing for temporary or continuous heating and / or cooling. Furthermore, stirring or vibration can be performed during the mixing process.

[0133] [13. Characteristics of resin composition, resin composition layer and its cured product] The cured product obtained by curing the above-mentioned resin composition has high light transmittance. Therefore, when a resin sheet containing a resin composition layer is formed, a solder resist layer with high light transmittance can be formed. For example, the thickness of the cured product of the resin composition is 50 μm, and the light transmittance T900 at a measurement wavelength of 900 nm is preferably 70% or more, more preferably 73% or more, particularly preferably 75% or more, and usually 100% or less.

[0134] The cured product obtained by curing the above-mentioned resin composition may have a low light transmittance in the visible light wavelength range. For example, there may be a large difference between the light transmittance T900 of a 50 μm thick cured product at a wavelength of 900 nm and the light transmittance T550 of a 50 μm thick cured product at a wavelength of 550 nm. In one embodiment, the aforementioned difference in light transmittance T900-T550 is preferably 15% or more, more preferably 20% or more, particularly preferably 25% or more, preferably 70% or less, more preferably 60% or less, and particularly preferably 50% or less.

[0135] The cured product obtained by curing the above-mentioned resin composition can generally reduce the difference in light transmittance caused by thickness variations. Therefore, the cured product of the resin composition generally maintains high light transmittance even when the thickness varies. Due to the increasing size of semiconductor wafer packaging in recent years, solder resist layers tend to be thicker. Depending on the surface shape of the substrate on which the solder resist layer is formed, the solder resist layer can be formed in thick and thin sections. When the cured product of the above-mentioned resin composition is used as a solder resist layer, high light transmittance can be obtained in both thick and thin sections. In particular, it can reduce the difference in light transmittance caused by thickness variations, so even if the thickness difference between thick and thin sections is large, high light transmittance can be obtained in both thick and thin sections. Therefore, the range of solder resist layer thicknesses can be expanded, or the range of applicable substrates can be expanded.

[0136] For example, the difference ΔT(900nm) between the transmittance T(40μm / 900nm) of the cured resin composition with a thickness of 40μm and a light transmittance T(100μm / 900nm) at a wavelength of 900nm and a thickness of 100μm is preferably 0% to 30%, more preferably 0% to 25%, and particularly preferably 0% to 20%. Furthermore, the difference ΔT(550nm) between the transmittance T(40μm / 550nm) of the cured resin composition with a thickness of 40μm and a light transmittance T(100μm / 550nm) at a wavelength of 550nm and a thickness of 100μm is preferably 0% to 50%, more preferably 0% to 45%, and particularly preferably 0% to 40%.

[0137] The cured product obtained by curing the above-mentioned resin composition preferably exhibits a greater variation in light transmittance in the wavelength range near 780 nm, which is at the long wavelength end of the visible light wavelength range. For example, the ratio T700 / T800 of the cured product with a thickness of 50 μm and a light transmittance T700 measured at a wavelength of 700 nm to the light transmittance T800 of the cured product with a thickness of 50 μm and a light transmittance T800 measured at a wavelength of 800 nm is preferably in the range of less than 1.0. In one embodiment, the aforementioned light transmittance ratio T700 / T800 is preferably 0.3 to 0.8, more preferably 0.3 to 0.6, and particularly preferably 0.3 to 0.4.

[0138] The cured product obtained by curing the above-mentioned resin composition exhibits a smaller variation in light transmittance over longer wavelengths compared to the visible light wavelength range. For example, the difference between the light transmittance T900 at a wavelength of 900 nm and the light transmittance T1500 at a wavelength of 1500 nm for a thickness of 50 μm of the cured product can be small. In one embodiment, the absolute value of the aforementioned difference in light transmittance, |T900-T1500|, is preferably 0% to 30%, more preferably 0% to 25%, and particularly preferably 0% to 20%.

[0139] The light transmittance of the cured resin composition can be measured using a UV-NIR spectrophotometer (e.g., Shimadzu Corporation's "UV3100PC"). Specific measurement conditions can be as described in the examples below.

[0140] The aforementioned resin composition is preferably tack-resistant. Therefore, the resin composition layer can also have low tack, resulting in good workability of the resin sheet. This tack can be represented by the peeling force required to pull away a probe in contact with the resin composition layer. In one embodiment, the peeling force is preferably less than 0.6 N, more preferably less than 0.4 N.

[0141] The aforementioned peel force can be measured by the following method. A cylindrical SUS probe with a bottom surface having a diameter of 5 mm is brought into contact with the resin composition layer at a contact speed of 0.5 cm / s and held for 1 second under a load of 1000 gf / cm². Then, the probe is pulled away at 0.5 cm / s, and the peel force required for pull-away is measured as an indicator of adhesion. The specific measurement method can be the method described in the examples.

[0142] The aforementioned resin composition preferably has a low melt viscosity. Therefore, when using resin sheets to encapsulate circuit boards or semiconductor wafers to form solder resist layers, the resin composition layer can achieve good embedding properties. In one embodiment, the lowest melt viscosity of the resin composition within a temperature range of 60°C to 200°C is preferably below 20,000 poise.

[0143] The aforementioned minimum melt viscosity of the resin composition can be measured using a dynamic viscoelasticity measuring device, with the resin composition heated at a rate of 5°C / min while the temperature is increased from an initial temperature of 60°C to 200°C, and the measurement is performed at temperature intervals of 2.5°C and vibration at 1 Hz / deg. Specific measurement methods can be adopted as described in the examples.

[0144] The cured form of the aforementioned resin composition preferably has a low modulus of elasticity. Therefore, warpage of printed circuit boards and semiconductor wafer packages having a solder resist layer formed by the cured resin composition layer can be effectively suppressed. In one embodiment, the tensile modulus of elasticity of the cured form 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; for example, it can be 1 GPa or more.

[0145] The tensile modulus of elasticity of the cured resin composition, as described above, is obtained using a cured resin composition cured at 190°C for 90 minutes. According to JIS K7127, it can be measured at 25°C. Specific measurement methods can be adopted as described in the examples.

[0146] The cured resin composition preferably exhibits high adhesion to substrates formed from various types of resins. Therefore, the solder resist layer formed by the cured resin composition layer can achieve high adhesion to substrates where the solder resist layer is disposed. In one embodiment, the peel strength of the cured resin composition to the polyimide film is preferably greater than 2 kgf / cm.

[0147] The peel strength of the cured resin composition, as described above, can be determined using the following method. A laminated resin composition layer and a polyimide film are cured at 180°C for 90 minutes to form a solder resist layer. Then, the polyimide film is pulled away from the solder resist layer at a speed of 50 mm / min in the direction perpendicular to the solder resist layer, and the peel strength can be measured. The specific measurement method can be the one described in the examples.

[0148] The solder resist layer formed by the hardened resin composition layer is preferably capable of suppressing warpage of the printed circuit board and semiconductor wafer package having the solder resist layer. In one embodiment, the warpage of the sample substrate of the semiconductor wafer package obtained by forming the solder resist layer on the silicon wafer is preferably less than 1 mm, more preferably less than 0.8 mm, and particularly preferably less than 0.6 mm. The aforementioned warpage refers to the solder resist layer formed as a hardened layer on a 12-inch wafer by curing a photosensitive resin composition. It can be measured using a TherMoiré measuring apparatus (e.g., Akorometrix's "Thermoire AXP") at 25°C, according to JEITA EDX-7311-24 specifications. The specific measurement method can be the method described in the examples.

[0149] The inventors believe that the design can achieve the above-mentioned excellent characteristics as follows. Generally, when the cured layer of a resin composition is thick, the light transmittance of that layer tends to decrease. In contrast, the (B) inorganic filler contained in the resin composition of the above embodiment has a larger specific surface area and a smaller particle size. The particles of this smaller-sized (B) inorganic filler have a wavelength smaller than that of light, thus suppressing light reflection from the particle surface. In particular, by appropriately adjusting the composition of the resin components, particle aggregation can be suppressed, or the refractive index difference at the interface between the particles and the resin components can be reduced, thus effectively suppressing reflection. Therefore, the cured resin composition can have high light transmittance. Thus, a thick solder resist layer with high light transmittance can be achieved through the cured resin composition layer.

[0150] Furthermore, generally, when the cured layer of the resin composition is thicker, the effects of temperature changes on the expansion and contraction of the cured layer become greater, reducing the dimensional stability of the layer and making it prone to cracking. To suppress expansion and contraction, the amount of inorganic filler can be increased; however, with more inorganic filler, there has been a tendency for reduced light transmittance or increased elastic modulus, leading to warping. In contrast, the resin composition layer of the above embodiment uses (B) inorganic filler with a specific surface area, so even with a larger amount of (B) inorganic filler, a cured product with high light transmittance can be obtained. Furthermore, the resin composition layer of the above embodiment can use resin components such as (A) thermosetting resin and (C) elastomer combined with (B) inorganic filler, some or all of which have a soft molecular backbone. Therefore, even if (B) contains more inorganic filler, the elastic modulus of the hardened material can be reduced, thereby suppressing the warping of printed circuit boards and semiconductor wafer packages with solder resist layers formed by the hardened material.

[0151] Furthermore, the inorganic filler in embodiment (B) described above can be a component that improves the viscosity and minimum melt viscosity of the resin composition, or can enhance the adhesion of the solder resist layer formed by the hardened resin composition layer. Therefore, a thick solder resist layer with high light transmittance can be achieved, and furthermore, the viscosity and minimum melt viscosity of the resin composition can be reduced, while the adhesion of the solder resist layer can be improved. However, the scope of the technology of this invention is not limited to the design described herein.

[0152] [14. Any component that the resin sheet may possess] In one embodiment of the present invention, the resin sheet is combined with a resin composition layer and may further include any component. For example, the resin sheet may include a support as an arbitrary component. Typically, the aforementioned resin composition layer is disposed on the support.

[0153] Examples of supports include films made of plastic materials, metal foils, and release paper, with films and metal foils made of plastic materials being more preferred.

[0154] When a film made of plastic material is used as a support, examples of plastic materials include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), acrylonitrile polycarbonate (hereinafter sometimes abbreviated as "PC"), polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0155] When using metal foil as a support, examples of metal foils include copper foil and aluminum foil, with copper foil being preferred. Copper foil can be used as the copper foil, either as a single metal or as an alloy of copper with other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

[0156] The support can be treated with matte finish, corona treatment, or antistatic treatment on the surface where it bonds with the resin composition layer.

[0157] As a support, a support with a release layer can be used on the surface where it bonds to the resin composition layer. The release agent used in the release layer of the support with the release layer can be, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and polysiloxane resins. Commercially available products can also be used as supports with the release layer, such as PET films having a release layer with an alkyd resin-based release agent as the main component, such as Lintec's "SK-1," "AL-5," and "AL-7," Toray's "Lumirror T60," Teijin's "Purex," and Unitika's "Unipeel."

[0158] The thickness of the support is not particularly limited, but is preferably in the range of 5μm to 75μm, and more preferably in the range of 10μm to 60μm. Furthermore, when using a support with an attached release layer, the overall thickness of the support with the release layer is preferably within the above-mentioned range.

[0159] In one embodiment of the present invention, the resin sheet is combined with a resin composition layer, and may further include a protective film as an arbitrary component. Typically, the protective film is provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). The protective film may also be the same as the film that can be used as the support. The thickness of the protective film is not particularly limited, for example, 1 μm to 40 μm. The resin sheet with the protective film can inhibit the adhesion of dirt or scratches to the surface of the resin composition layer.

[0160] [15. Method for manufacturing resin sheets] There are no particular limitations on the manufacturing method of resin sheets. For example, resin sheets can be manufactured by coating a liquid resin composition onto a support. Alternatively, resin sheets can be manufactured by dissolving and / or dispersing a resin composition in a solvent to obtain a varnish as a liquid resin composition, and then coating this varnish onto a support. Coating can be performed using a coating apparatus such as a die coater. Furthermore, drying can be performed if necessary after coating.

[0161] As a solvent, examples include those that are the same solvents listed in the composition description of the resin. A single type of solvent may be used alone, or two or more types may be used in combination.

[0162] Drying can be carried out by methods such as heating or blowing hot air. There are no particular limitations on drying conditions, but the solvent content in the resin composition layer is usually less than 10% by mass, preferably less than 5% by mass. Depending on the boiling point of the solvent in the resin composition, for example, when using a resin composition containing 30% to 60% by mass of solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0163] Resin sheets can be stored in rolls. When resin sheets have a protective film, the protective film can usually be peeled off for use.

[0164] [16. Printed Wiring Board] One embodiment of the present invention provides a printed circuit board comprising a solder resist layer formed by a hardened resin composition layer of the aforementioned resin sheet. The solder resist layer typically has a thickness in the same range as the resin composition layer. Furthermore, even when relatively thick, the solder resist layer exhibits high light transmittance. Preferably, the solder resist layer has a low modulus of elasticity, thus suppressing warpage of the printed circuit board and semiconductor wafer package incorporating the solder resist layer. Additionally, the solder resist layer preferably exhibits high-density bonding with the circuit substrate.

[0165] Typically, a printed circuit board (PCB) comprises a circuit substrate and a solder resist layer disposed on the circuit substrate. This PCB can be manufactured, for example, by a manufacturing method comprising the following steps: (I) The method of bonding the circuit board to the resin composition layer, and the steps of depositing resin sheets onto the circuit board. (II) Step of using a resin composition layer to harden and form a solder resist layer.

[0166] The "circuit substrate" used in step (I) refers to the substrate on which a solder resist layer is to be further formed during the manufacturing of a printed wiring board. Examples include substrates with circuit wiring. The number of layers and other layer configurations of the circuit wiring are not particularly limited and can be appropriately selected according to the desired characteristics of the printed wiring board. Furthermore, this circuit substrate may contain semiconductor chips. Examples of circuit substrates include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. Circuit wiring can be formed on one or both sides of these substrates.

[0167] The thickness of the circuit board is not particularly limited, but it is preferably 10μm or more, more preferably 20μm or more, and more preferably 800μm or less, 600μm or less, or 400μm or less. The thickness of the circuit board refers to the overall thickness of the circuit board, including the thickness of the surface circuitry.

[0168] When circuit wiring is formed on the surface of a circuit board, the thickness of the circuit wiring is not particularly limited. From the viewpoint of making printed circuit boards thinner, it is preferable to be 40μm or less, more preferably 30μm or less, even more preferably 25μm or less, even more preferably 20μm or less, 18μm or less, 16μm or less, 14μm or less, 12μm or less, or 10μm or less. The lower limit of the thickness of the surface circuit is not particularly limited, for example, it can be 1μm or more, 3μm or more, 5μm or more, etc.

[0169] From the viewpoint of suppressing circuit deformation or cracking, the coefficient of thermal expansion of the circuit board is preferably below 16 ppm / ℃, more preferably below 14 ppm / ℃, and even more preferably below 12 ppm / ℃. The lower limit of the coefficient of thermal expansion of the circuit board varies depending on the composition of the resin used to form the solder resist layer, and is preferably above -2 ppm / ℃, more preferably above 0 ppm / ℃, and even more preferably above 4 ppm / ℃. The aforementioned coefficient of thermal expansion of the circuit board is the linear coefficient of thermal expansion in the planar direction over a temperature range of 25℃ to 150℃, obtained by thermomechanical analysis (TMA) using the tensile-weighted method. Examples of thermomechanical analysis devices that can be used to measure the linear coefficient of thermal expansion of the circuit board include Rigaku's "Thermo Plus TMA8310" and Seiko Instruments' "TMA-SS6100".

[0170] The deposition of a circuit board and a resin sheet can be achieved, for example, by heating and pressing the resin sheet onto the circuit board from the support side. The component used to heat and press the resin sheet onto the circuit board (hereinafter sometimes referred to as a "heat-pressing component") can be, for example, a heated metal plate (SUS mirror plate, etc.) or a metal roller (SUS roller). Furthermore, it is preferable not to directly press the heat-pressing component onto the resin sheet, but rather to press the resin composition layer using an elastic material such as heat-resistant rubber, which can adequately follow the surface irregularities of the circuitry on the circuit board.

[0171] The deposition of the circuit board and the resin film can be performed using a vacuum deposition method. In the vacuum deposition method, the heating and pressing temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C; the heating and pressing pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa; and the heating and pressing time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Deposition is preferably performed under reduced pressure conditions below 26.7 hPa.

[0172] Lamination can be performed using commercially available vacuum laminators. Examples of commercially available vacuum laminators include the vacuum pressure laminator manufactured by Meiki Manufacturing Co., Ltd., the vacuum coating machine manufactured by Nikko-Materials Co., Ltd., and the batch vacuum pressure laminator.

[0173] After lamination, the laminated resin sheet can be smoothed under normal pressure (atmospheric pressure), for example, by pressing the heated bonding member from the support side. The pressing conditions for smoothing can be the same as the heating and pressing conditions for lamination described above. Smoothing can be performed using a commercially available laminator. Furthermore, lamination and smoothing can also be performed continuously using the aforementioned commercially available vacuum laminator.

[0174] When the resin sheet has a support, the support can be removed between step (I) and step (II), or it can be removed after step (II).

[0175] In step (II), the resin composition layer is hardened to form a solder resist layer composed of the hardened resin composition layer. The hardening of the resin composition layer is usually carried out by heat curing.

[0176] The thermosetting conditions of the resin composition layer vary depending on the type of resin components contained in the resin composition. 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.

[0177] Heat curing can be carried out at atmospheric pressure (normal pressure). Furthermore, heat curing can be performed multiple times. For example, before step (III) described later, step (II) can be performed multiple times; before step (III) described later, step (II) can be performed more than once; and further, after steps (III) and (IV), heat curing can be performed more than once.

[0178] The manufacturing method of the printed circuit board combines steps (I) and (II), and may further include any additional steps. For example, the manufacturing method of the printed circuit board may also include a step of forming an opening in the solder resist layer in (III), and a step of removing solder resist residue from the solder resist layer in (IV). After step (II), when peeling off the support, the peeling off of the support may be performed between steps (II) and (III), between steps (III) and (IV), or after step (IV).

[0179] In step (III), an opening is formed in the solder resist layer. Methods for forming the opening include, for example, drilling, laser, and plasma. When forming the opening by laser, laser light sources include, for example, carbon dioxide lasers, YAG lasers, and excimer lasers. From the perspective of processing speed and cost, carbon dioxide lasers are preferred. The size and shape of the opening can be appropriately determined according to the design of the printed circuit board.

[0180] In step (IV), the solder resist layer undergoes a desmearing process. The interior of the opening formed in step (III) may contain resin residue. This residue can cause poor electrical connections. Therefore, in step (IV), a desmearing process is performed to remove the residue.

[0181] Descaling can be carried out by dry descaling, wet descaling, or a combination thereof.

[0182] Dry desmearing processes include, for example, plasma desmearing. Plasma desmearing can be performed using commercially available plasma desmearing equipment. Among commercially available plasma desmearing equipment, examples better suited for printed circuit board manufacturing include Nissin's microwave plasma equipment and Sekisui Chemicals' atmospheric pressure plasma etching equipment.

[0183] Wet degumming treatment can include, for example, degumming treatment using oxidizing solutions. When using oxidizing solutions for degumming treatment, it is preferable to proceed in the following order: swelling treatment with a swelling solution, oxidation treatment with an oxidizing solution, and neutralization treatment with a neutralizing solution.

[0184] Examples of swelling solutions include alkaline solutions and surfactant solutions, with alkaline solutions being preferred. More preferably, sodium hydroxide or potassium hydroxide solutions are used. Commercially available swelling solutions include, for example, "Swelling Dip Securiganth P" and "Swelling Dip Securiganth SBU" manufactured by Atotech Japan. Swelling treatment is performed by immersion in a swelling solution at 30°C to 90°C for 1 to 20 minutes.

[0185] The oxidizing agent solution is preferably an alkaline permanganate aqueous solution, such as a solution of potassium permanganate or sodium permanganate dissolved in an aqueous sodium hydroxide solution. The roughening treatment by the oxidizing agent solution is preferably achieved by immersing the solder resist layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. Furthermore, the concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Commercially available oxidizing agents include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securiganth P" manufactured by Atotech Japan.

[0186] The preferred neutralizing solution is an acidic aqueous solution. Commercially available products include, for example, "Reduction solution Securiganth P" manufactured by Atotech Japan. The surface roughened by the oxidant can be immersed in the neutralizing solution at 30°C to 80°C for 5 to 30 minutes for neutralization treatment.

[0187] When implementing a combination of dry and wet degumming treatment, either the dry or wet degumming treatment can be performed first.

[0188] [17. Semiconductor Wafer Packaging] One embodiment of the present invention provides a semiconductor wafer package comprising a solder resist layer formed from a hardened resin composition layer of the aforementioned resin sheet. The solder resist layer typically has a thickness in the same range as the resin composition layer. Furthermore, even if the solder resist layer is relatively thick as described above, it can still exhibit high light transmittance. Additionally, the solder resist preferably has a low modulus of elasticity, thus suppressing warpage of the printed circuit board and the semiconductor wafer package in which the solder resist layer is provided. Moreover, the solder resist layer preferably provides high-density bonding to components of the semiconductor wafer package other than the solder resist layer.

[0189] Semiconductor wafer packages typically include a semiconductor wafer and a solder resist layer. Examples of semiconductor wafer packages include FC-CSP, MIS-BGA, ETS-BGA, Fan-out WLP (Wafer Level Package), Fan-in WLP, Fan-out PLP (Panel Level Package), and Fan-in PLP. Furthermore, the solder resist layer for semiconductor wafer packages other than those illustrated herein can also be formed by curing the resin composition layer of the aforementioned resin film.

[0190] The following is a detailed description using a fan-out type WLP. Figure 1 is a schematic cross-sectional view of a semiconductor wafer package 100 according to one embodiment of the present invention. As shown in Figure 1, the semiconductor wafer package 100, as an example, includes a semiconductor wafer 110; a sealing layer 120 forming around the semiconductor wafer 110; a redistribution layer 130 serving as an insulating layer disposed on the side opposite to the sealing layer 120 of the semiconductor wafer 110; a redistribution layer 140 serving as a conductor layer; a solder resist layer 150; and bumps 160.

[0191] The manufacturing method of this semiconductor wafer package includes, for example, the following steps: (i) The step of depositing a temporary fixed film onto a substrate, (ii) The step of temporarily fixing the semiconductor wafer onto the temporary fixing film. (iii) The step of forming a sealing layer on a semiconductor wafer. (iv) The step of peeling the substrate and the temporary fixing film from the semiconductor wafer. (v) The step of forming a redistribution layer on the surface of the semiconductor wafer where the substrate and temporary fixing film have been peeled off. (vi) The step of forming a rewiring layer as a conductor layer on the rewiring forming layer, and (vii) The step of forming a solder resist layer on the rewiring layer. Furthermore, the aforementioned semiconductor wafer packaging manufacturing method may also include the following steps: (viii) The steps for performing bumping processing, and (ix) The steps of cutting a plurality of semiconductor wafer packages into individual semiconductor wafer packages.

[0192] In step (i), a temporary fixing film is deposited on the substrate. The deposition of the substrate and the temporary fixing film is performed in the same way as the deposition of the circuit substrate and the resin film in the method for manufacturing a printed circuit board.

[0193] Examples of substrates include silicon wafers; glass wafers; glass substrates; metal substrates such as copper, titanium, stainless steel, and cold-rolled steel sheets (SPCC); substrates such as FR-4 substrates in which thermosetting resins such as epoxy resins are infiltrated into glass fibers for thermosetting treatment; substrates made of bismaleimide triazine resins such as BT resins; and so on.

[0194] Temporarily fixed films can be used to temporarily fix semiconductor wafers after being peeled off. Commercially available products include "Riva Alpha" manufactured by Nitto Denko Corporation.

[0195] In step (ii), the semiconductor wafer is temporarily fixed onto the temporary fixing film. The temporary fixing of the semiconductor wafer can be performed using devices such as flip-chip bonding machines or die bonding machines. The layout and number of semiconductor wafers can be appropriately set based on the shape and size of the temporary fixing film, the production quantity of the intended semiconductor wafer package, and other conditions. For example, the semiconductor wafers can be temporarily fixed in a matrix arrangement with multiple rows and columns.

[0196] In step (iii), a sealing layer is formed on the semiconductor wafer. The sealing layer is typically formed by a method comprising a resin composition layer for forming the sealing layer on the semiconductor wafer and by curing this resin composition layer to form the sealing layer. The resin composition layer for the sealing layer can be formed from a curable resin composition or a photocurable resin composition. Furthermore, the resin composition layer for the sealing layer can be the same as the resin composition layer used for forming the solder resist layer described above. This sealing layer can, for example, be formed by the same method as described in the section on printed circuit boards for laminating and curing resin films on a circuit board.

[0197] In step (iv), the substrate and the temporary fixing film are peeled off from the semiconductor wafer. The peeling method is preferably an appropriate method based on the material of the temporary fixing film. Examples of peeling methods include heating, foaming, or expanding the temporary fixing film to perform peeling. Another example of a peeling method is to irradiate the temporary fixing film with ultraviolet light through the substrate to reduce the adhesion of the temporary fixing film and perform peeling. In methods involving heating, foaming, or expanding the temporary fixing film for peeling, the heating conditions are typically 100°C to 250°C for 1 second to 90 seconds or 5 minutes to 15 minutes. In methods involving irradiating the temporary fixing film with ultraviolet light to reduce its adhesion and perform peeling, the ultraviolet irradiation dose is typically 10 mJ / cm² to 1000 mJ / cm².

[0198] As mentioned above, when the substrate and temporary fixing film are peeled off from the semiconductor wafer, the surface of the sealing layer is exposed. The manufacturing method of semiconductor wafer packaging may include grinding this exposed surface of the sealing layer. Grinding improves the smoothness of the sealing layer surface.

[0199] In step (v), a rewiring layer serving as an insulating layer is formed on the surface of the semiconductor wafer where the substrate and the temporary fixing film have been peeled off. Typically, this rewiring layer is formed on the semiconductor wafer and the sealing layer. The material of the rewiring layer can be any insulating material. The rewiring layer can be formed by curing a resin composition for the rewiring layer. This rewiring layer can, for example, be formed by a method that includes forming a resin composition layer and curing this resin composition layer. The resin composition layer for the rewiring layer can be formed by a thermosetting resin composition or a photocurable resin composition. Furthermore, the resin composition layer for the rewiring layer can be the same as the resin composition layer used for forming the solder resist layer described above. This rewiring layer can, for example, be formed by the same method as described in the section on printed wiring boards for laminating and curing resin films on a circuit board.

[0200] To enable interlayer bonding between the semiconductor wafer and the rewiring layer, vias can be formed in the rewiring layer. The shape of the vias is not particularly limited, but is generally circular (or slightly circular). The top diameter of the via 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 refers to the diameter of the opening of the via on the surface of the rewiring layer.

[0201] In step (vi), a rewiring layer, serving as a conductor layer, is formed on the rewiring forming layer. The rewiring layer can be formed using a conductor material such as a metal. Furthermore, the rewiring layer can be a single metal layer or an alloy layer. The thickness of the rewiring layer is determined by the desired semiconductor wafer package design, typically 3μm to 35μm, preferably 5μm to 30μm. Methods for forming the rewiring layer include, for example, plating. For instance, a rewiring layer with the desired wiring pattern can be formed by plating using methods such as semi-additive or fully additive methods. From the viewpoint of ease of manufacturing, the semi-additive method is preferred. Furthermore, steps (v) and (vi) are repeated, and the rewiring layer and the rewiring forming layer can be alternately deposited (layering).

[0202] In step (vii), a solder resist layer is formed on the rewiring layer. The solder resist layer is formed using the aforementioned resin sheet. Typically, the solder resist layer is formed by laminating resin sheets, including bonding the rewiring layer to the resin composition layer, and then curing the resin composition layer. The lamination of the resin sheet on the rewiring layer can be performed using the same method as for the lamination of resin sheets on the circuit board described in the printed wiring board section. Furthermore, the curing of the resin composition layer can be performed using the same method as for the curing of the resin composition layer described in the printed wiring board section. Additionally, step (vii) may, if necessary, include forming an opening in the solder resist layer and performing a desmearing treatment on the solder resist layer. The formation of the opening and the desmearing treatment are performed using the same method as described in the printed wiring board section.

[0203] The manufacturing method for semiconductor wafer packaging may, where necessary, include a bump forming process (viii). Bump forming can be performed by methods such as soldering balls or solder plating.

[0204] The manufacturing method of semiconductor wafer packages may, if necessary, include the step of cutting a plurality of semiconductor wafer packages into individual semiconductor wafer packages for monolithic assembly (ix).

[0205] [18. Semiconductor Devices] One embodiment of the present invention provides a semiconductor device comprising the aforementioned printed circuit board or semiconductor wafer package. The semiconductor device can be manufactured using a printed circuit board or semiconductor wafer package.

[0206] Semiconductor devices include, for example, various semiconductor devices supplied to electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trams, ships, and aircraft). [Example]

[0207] The present invention will be specifically described below with examples. However, the present invention is not limited to these examples. In the following description, the terms "parts" and "%" to indicate quantities, unless otherwise specified, refer to "parts by mass" and "% by mass". In particular, when the temperature is not specified, the temperature and pressure conditions are room temperature (25°C) and atmospheric pressure (1 atm).

[0208] [Manufacturing Example 1. Synthesis of Polymer Resin A] In a reaction vessel, 69 g of difunctional hydroxyl-terminated polybutadiene (Japan Soda Co., Ltd. "G-3000", number average molecular weight = 3000, hydroxyl equivalent = 1800 g / eq.), 40 g of aromatic hydrocarbon mixed solvent (Ipsol 150, Idemitsu Petrochemical Co., Ltd.), and 0.005 g of dibutyltin laurate were added and mixed to ensure uniform dissolution. Once homogeneous, the temperature was raised to 60°C, and then 8 g of isophorone diisocyanate (Evonik Degussa Japan Co., Ltd. "IPDI", isocyanate equivalent = 113 g / eq.) was added while stirring, and the reaction was carried out for approximately 3 hours.

[0209] Next, 23 g of cresol-formaldehyde varnish resin (DIC Corporation "KA-1160", hydroxyl equivalent = 117 g / eq.) and 60 g of ethyl diethylene glycol acetate (DAICEL Corporation) were added to the reactants. The mixture was stirred and heated to 150°C for approximately 10 hours. FT-IR confirmed the disappearance of the NCO peak at 2250 cm⁻¹. The disappearance of the NCO peak was considered the endpoint of the reaction, and the reactants were cooled to room temperature. The reactants were then filtered through a 100-mesh filter to obtain a polymer resin with a butadiene structure and phenolic hydroxyl groups (butadiene resin containing phenolic hydroxyl groups: 50% by mass of non-volatile components). The number-average molecular weight of polymer resin A was 5900, and the glass transition temperature was -7°C.

[0210] [Manufacturing 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%, Kuraray "C-1015N") and 0.01 g of dibutyltin dilaurate were uniformly dissolved in 37.6 g of diethylene glycol monoethyl ether acetate (DAICEL "ethyl diethylene glycol acetate"). The mixture was then heated to 50°C, and further, while stirring, 27.8 g of toluene-2,4-diisocyanate (isocyanate equivalent: 87.08) was added, and the reaction was carried out for approximately 3 hours. The reactants were cooled to room temperature, and then 14.3 g of benzophenone tetracarboxylic dianhydride (anhydride equivalent: 161.1 g / eq), 0.12 g of triethylenediamine, and 84.0 g of diethylene glycol monoethyl ether acetate (DAICL "ethyl diethylene glycol acetate") were added. The mixture was stirred and heated to 130 °C for approximately 4 hours. The disappearance of the NCO peak at 2250 cm⁻¹ was confirmed by FT-IR. The disappearance of the NCO peak was considered the endpoint of the reaction. The reactants were cooled to room temperature and filtered through a 100 μm filter cloth to obtain polymer resin D (50% by mass, non-volatile content) with an imine structure, a carbamate structure, and a polycarbonate structure. The number average molecular weight was 8500.

[0211] [Example 1] Three parts of an epoxy resin mixture (a mixture of bisphenol A and bisphenol F epoxy resins, NIPPON STEEL Chemical & Material Co., Ltd.'s "ZX-1059", epoxy equivalent 170 g / eq.), three parts of naphthalene-type epoxy resin (DIC Co., Ltd.'s "HP4032D", epoxy equivalent 140 g / eq.), four parts of a phenolic curing agent (DIC Co., Ltd.'s "LA-3018-50P", active group equivalent approximately 151 g / eq., 50% 2-methoxypropanol solution of non-volatile components), three parts of maleimide resin (Designa Molecules Co., Ltd.'s "BMI-689"), and two parts of inorganic filler (average particle size 0.3 μm, specific surface area 10.5 m²). 2 / g of 65 parts of silica particles (surface-treated with silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Industry Co., Ltd.), 20 parts of polymer resin A (50% non-volatile component), 0.05 parts of imidazole curing accelerator (manufactured by Shikoku Chemical Industry Co., Ltd., "1B2PZ"), 0.05 parts of organic pigment (Pigment green36, manufactured by Dai-Nippon Seikou Chemical Co., Ltd., "CG5370"), 0.05 parts of organic pigment (Pigment blue 15:3, manufactured by Toyo Ink Manufacturing Co., Ltd., "FG7351"), and 15 parts of methyl ethyl ketone as solvent were mixed and uniformly dispersed in a high-speed rotary mixer to produce a resin varnish.

[0212] Next, a resin varnish was uniformly coated onto a polyethylene terephthalate film (Toray Industries' "Lumirror T6AM", 38 μm thick) serving as the support, with the dried resin composition layer having a thickness of 50 μm. The film was then dried at 80°C to 120°C (average 100°C) for 6 minutes to form the resin composition layer. A rough-surfaced protective film (polypropylene film, Oji F-Tex's "alphanMA-430", 20 μm thick) was prepared and its rough surface was adhered to the resin composition layer, resulting in a resin sheet composed of a support, a resin composition layer, and a protective film.

[0213] [Example 2] Three parts of the epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd. "ZX-1059") were replaced with three parts of a naphthylene ether-type epoxy resin (DIC Co., Ltd. "HP6000L", epoxy equivalent 213 g / eq.). Furthermore, 1.5 parts of an active ester resin (DIC Co., Ltd. "HPC-8000L-65TM", an active ester resin containing a dicyclopentadiene-type bisphenol structure, a 1:1 solution of toluene:MEK with 65% by mass of non-volatile components, functional group equivalent 281 g / eq.) were added to the resin varnish. Further, the amount of the phenolic curing agent (DIC Co., Ltd. "LA-3018-50P", non-volatile components 50%) was changed from four parts to two parts. Furthermore, instead of 65 parts of inorganic filler 2, 90 parts of inorganic filler 3 (silica particles with an average particle size of 1.0 μm and a specific surface area of ​​4.3 m² / g, surface-treated with silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) were used. Further, the amount of polymer resin A (50% non-volatile component) was changed from 20 parts to 40 parts. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0214] [Example 3] Three parts of the epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd. "ZX-1059") were replaced with three parts of glycidylamine-type epoxy resin (Mitsubishi Chemical Co., Ltd. "JER630LSD", epoxy equivalent 95 g / eq.). Furthermore, the amount of phenolic curing agent (DIC Co., Ltd. "LA-3018-50P", non-volatile component 50%) was changed from four parts to two parts. Further, three parts of cresol-formaldehyde varnish resin (DIC Co., Ltd. "KA-1163", phenolic hydroxyl equivalent 118 g / eq.) were added to the resin varnish. Also, the amount of maleimide resin (Designa Molecules Co., Ltd. "BMI-689") was changed from three parts to six parts. In addition, instead of 65 parts of inorganic filler 2, 50 parts of inorganic filler 1 (silicon dioxide particles with an average particle size of 0.1 μm, a specific surface area of ​​30.1 m² / g, and surface treated with hexamethyldisilazane (HMDS)) were used. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0215] [Example 4] Three parts of an epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd. "ZX-1059") and three parts of a naphthalene-type epoxy resin (DIC Co., Ltd. "HP4032D") were replaced with three parts of a glycidylamine-type epoxy resin (Mitsubishi Chemical Co., Ltd. "JER630LSD", epoxy equivalent 95 g / eq.) and three parts of a dicyclopentadiene-type epoxy resin (DIC Co., Ltd. "HP7200", epoxy equivalent 258 g / eq.). Four parts of a phenolic curing agent (DIC Co., Ltd. "LA-3018-50P", non-volatile component 50%) were replaced with a cresol-formaldehyde varnish resin (DIC Co., Ltd. "KA-1163", phenolic hydroxyl equivalent 118 g / eq.). Furthermore, maleimide resin (Designa Molecules Co., Ltd. "BMI-689") was not used. Furthermore, instead of 20 parts of polymer resin A (50% non-volatile component), 10 parts of phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", a 1:1 solution of cyclohexanone and methyl ethyl ketone (MEK) with 30% by mass of non-volatile component, Mw=35000) were used. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0216] [Example 5] Three parts of glycidylamine epoxy resin (JER630LSD, Mitsubishi Chemical, 95 g / eq.) were used instead of the epoxy resin mixture (NIPPON STEEL Chemical & Material, ZX-1059). The amount of phenolic curing agent (LA-3018-50P, DIC, 50% non-volatile component) was changed from four parts to two parts. Furthermore, three parts of cresol-formaldehyde varnish resin (KA-1163, DIC, 118 g / eq.) were added to the resin varnish. The amount of maleimide resin (BMI-689, Designa Molecules) was changed from three parts to six parts. Furthermore, 50 parts of inorganic filler 1 (silicon dioxide particles with an average particle size of 0.1 μm, a specific surface area of ​​30.1 m² / g, and surface-treated with hexamethyldisilazane (HMDS)) were used instead of 65 parts of inorganic filler 2. Also, 10 parts of an acrylic polymer containing hydroxyl groups (ARUFON UH-2000 manufactured by Toa Synthetic Co., Ltd., with a weight average molecular weight of 11,000) were used as an elastomer, replacing 20 parts of polymer resin A (50% non-volatile components). Additionally, 5 parts of cyclohexanone were added to the resin varnish. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0217] [Example 6] Resin varnish and resin sheets were manufactured by replacing 20 parts of polymer resin A (50% non-volatile component) with 4 parts of core-shell polymer particles (Dow Chemical Company's "EXL2655") as particulate elastomer, and adding 5 parts of cyclohexanone to the resin varnish, using the same method as in Example 1.

[0218] [Example 7] Except for replacing 20 parts of polymeric resin A (50% non-volatile component) with 20 parts of polymeric resin D (50% by mass of non-volatile component) manufactured in Example 2, resin varnish and resin film were manufactured by the same method as in Example 1.

[0219] [Example 8] Three parts of glycidylamine-type epoxy resin (JER630LSD, Mitsubishi Chemical, 95 g / eq.) were used instead of the epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd., "ZX-1059"). The amount of phenolic curing agent (LA-3018-50P, DIC Co., Ltd., 50% non-volatile component) was changed from four parts to two parts. Furthermore, three parts of cresol-formaldehyde varnish resin (KA-1163, DIC Co., Ltd., 118 g / eq.) were added to the resin varnish. Additionally, 50 parts of inorganic filler 1 (silicon dioxide particles with an average particle size of 0.1 μm, a specific surface area of ​​30.1 m² / g, and surface-treated with hexamethyldisilazane (HMDS)) were used instead of 65 parts of inorganic filler 2. In addition, 20 parts of polymer resin A (50% non-volatile component) were replaced with 5 parts of bismaleimide resin (Designer Molecules Co., Ltd. "BMI-3000", molecular weight 3000) as an elastomer. Furthermore, 5 parts of cyclohexanone were added to the resin varnish. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0220] [Comparative Example 1] Three parts of the epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd. "ZX-1059") were replaced with three parts of a naphthylene ether-type epoxy resin (DIC Co., Ltd. "HP6000L", epoxy equivalent 213 g / eq.). Additionally, 1.5 parts of an active ester resin (DIC Co., Ltd. "HPC-8000L-65TM", an active ester resin containing a dicyclopentadiene-type bisphenol structure, 65% by mass of a 1:1 solution of toluene:MEK with non-volatile components, and a functional group equivalent of 281 g / eq.) were added to the resin varnish. Furthermore, the amount of the phenolic curing agent (DIC Co., Ltd. "LA-3018-50P", non-volatile component 50%) was changed from four parts to two parts. Furthermore, instead of 65 parts of inorganic filler 2, 100 parts of inorganic filler 4 (silicon dioxide particles with an average particle size of 2.0 μm and a specific surface area of ​​2.5 m² / g, surface-treated with silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) were used. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0221] [Comparative Example 2] Three parts of the epoxy resin mixture (NIPPON STEEL Chemical & Material Co., Ltd. "ZX-1059") were replaced with three parts of a naphthylene ether-type epoxy resin (DIC Co., Ltd. "HP6000L", epoxy equivalent 213 g / eq.). Additionally, 1.5 parts of an active ester resin (DIC Co., Ltd. "HPC-8000L-65TM", an active ester resin containing a dicyclopentadiene-type bisphenol structure, 65% by mass of a 1:1 solution of toluene:MEK with non-volatile components, and a functional group equivalent of 281 g / eq.) were added to the resin varnish. Furthermore, the amount of the phenolic curing agent (DIC Co., Ltd. "LA-3018-50P", non-volatile component 50%) was changed from four parts to two parts. Furthermore, instead of 65 parts of inorganic filler 2, 100 parts of inorganic filler 4 (silicon dioxide particles with an average particle size of 2.0 μm and a specific surface area of ​​2.5 m² / g, surface-treated with silane coupling agent "KBM-573" manufactured by Shin-Etsu Chemical Industry Co., Ltd.) were used. In addition, the amount of polymer resin A (50% non-volatile component) was changed from 20 parts to 60 parts. In addition to the above, resin varnish and resin sheets are manufactured by the same method as in Example 1.

[0222] [Evaluation of the viscosity of the resin composition layer] The adhesion of the resin composition layer was determined using a probe tack test (TE-6002, manufactured by Test Industries Co., Ltd.) with an attached thermostatic bath. Specifically, the protective film of a resin sheet placed in a 25°C thermostatic bath was peeled off. A 5mm φ cylindrical probe (SUS) was then applied to the resin composition layer at a contact speed of 0.5 cm / s and held for 1 second under a load of 1000 gf / cm². The peeling force when the probe was pulled away at 0.5 cm / s was then measured as the probe adhesion (adhesion). The test was performed three times per sample, and the average value was calculated. An average probe adhesion (adhesion) less than 0.4 N was marked "○", 0.4 N or more but less than 0.6 N was marked "△", and 0.6 N or more was marked "×".

[0223] [Determination of the melt viscosity of the resin composition layer] The melt viscosity of the resin composition contained in the resin composition layer of a resin sheet was determined using a dynamic viscoelasticity measuring apparatus (UBM Rheosol-G3000). A 1g sample was taken from the resin composition layer and measured using a parallel plate with a diameter of 18mm. The measurement conditions were as follows: initial temperature 60°C to 200°C, heating rate 5°C / min, temperature interval 2.5°C, and vibration 1Hz / deg. The minimum melt viscosity was determined from the measured melt viscosity value. A minimum melt viscosity below 20,000 poise was marked as "0", and a minimum melt viscosity above 20,000 poise was marked as "×".

[0224] [Determination of the elastic modulus of hardened materials] Prepare a release PET film (Lintec Corporation "501010", thickness 38μm, side length 240mm) with a treated (release surface) and an untreated (untreated) surface. Place this release PET film onto a glass cloth substrate epoxy resin double-sided copper laminate (Panasonic Electric Works "R5715ES", thickness 0.7mm, side length 255mm) with the untreated surface of the release PET film in contact with the epoxy resin double-sided copper laminate. Secure the four sides of the release PET film to the epoxy resin double-sided copper laminate using polyimide adhesive tape (10mm wide).

[0225] Protective films were peeled off from resin sheets (167mm x 107mm) prepared according to the examples and comparative examples. A batch vacuum pressure laminator (Nikko-materials CVP700, a 2-stage laminator) was used to deposit the resin composition layer onto the release surface of the PET film in the center. The lamination process involved depressurizing for 30 seconds to below 13 hPa, followed by pressing at 100°C and 0.74 MPa for 30 seconds. Next, the support is peeled off, and the resin composition layer is thermo-cured at 190°C for 90 minutes.

[0226] After heat curing, the polyimide adhesive tape is peeled off, and the epoxy resin double-sided copper laminate of the glass cloth substrate is removed. Further, the release PET film is peeled off to obtain a sheet-like cured material. This sheet-like cured material is hereinafter referred to as the "evaluation cured material".

[0227] The hardened material for evaluation was cut into dumbbell-shaped pieces (No. 1) to obtain test specimens. The tensile strength of these specimens was determined using a tensile testing machine (ORIENTEC RTC-1250A), and the modulus of elasticity at 25°C was calculated. The measurements were performed according to JIS K7127. This procedure was repeated three times, and the average values ​​are shown in the table.

[0228] [Determination of light transmittance of hardened materials] Using a UV-NIR spectrophotometer (Shimadzu Corporation "UV3100PC"), the aforementioned hardened material (50 μm thick) was placed at the entrance opening of the integrating sphere, and the spectral transmittance was measured. Values ​​were recorded at measurement wavelengths of 550 nm, 700 nm, 800 nm, and 900 nm. Measurement conditions were as follows: Measurement wavelength range: 300 nm to 2600 nm; Sampling interval: 1 nm; Exposure time: 103 seconds (from start to end of measurement); Integrating sphere: present; Cut width: 20 nm.

[0229] Furthermore, aside from changing the coating thickness of the resin varnish, evaluation hardened materials with thicknesses of 40 μm and 100 μm were manufactured and their spectral transmittance was measured using the same method as in the previous embodiments. The spectral transmittance of the evaluation hardened materials (40 μm thickness and 100 μm thickness) was used to determine the measurement wavelengths of 550 nm and 900 nm.

[0230] [Evaluation of the adhesion of hardened materials] The resin sheets obtained in the above embodiments and comparative examples were peeled off, and the protective film was removed. Using a batch vacuum pressure laminator (Nikko-materials CVP700, a two-stage laminator), the resin composition layers were prepared and laminated by contacting the two sides of the epoxy resin on the glass cloth substrate with copper laminates (Panasonic Electric Works R5715ES, 0.7mm thick, 255mm angle). This lamination was performed by depressurization for 30 seconds, reducing the pressure to below 13 hPa, and then pressing for 30 seconds at 100°C and 0.74 MPa. Next, the laminated resin sheets were smoothed by hot pressing at atmospheric pressure, 100°C, and 0.5 MPa for 60 seconds. Then, the support was peeled off.

[0231] Prepare a polyimide film (12.5 μm thick, manufactured by Toray / DuPont, "Kapton 100EN"). Dry this polyimide film at 130°C for 30 minutes, then deposit it onto the aforementioned resin composition layer. This deposition is performed under the same conditions as the previous deposition. This yields an "intermediate composite II" consisting of a polyimide film, a resin composition layer, and a glass cloth substrate epoxy resin double-sided copper laminate.

[0232] The intermediate composite layer II was placed in an oven at 180°C and heated for an additional 90 minutes. This process was used to thermo-cure the resin composition layers, resulting in an "evaluation substrate A" that sequentially comprises a polyimide film, a solder resist layer as the curing agent of the resin composition layers, and a glass cloth substrate epoxy resin double-sided copper laminate.

[0233] Using evaluation substrate A, the adhesion (peel strength) between the polyimide film and the solder resist layer was measured. This peel strength was measured according to JIS C6481. Specifically, the peel strength was measured by the following procedure. For the polyimide film of substrate A, a rectangular portion with a width of 10 mm and a length of 100 mm was cut out. One end of this rectangular portion was peeled off and gripped with a gripper (TSE Corporation, Autocom type testing machine "AC-50C-SL"). A 35 mm length of the aforementioned rectangular portion was pulled away vertically, and the load (kgf / cm) at this pull-away was used as the peel strength measurement. The pull-away was performed at room temperature (25°C) at a speed of 50 mm / min.

[0234] A higher peel strength indicates better adhesion between the cured resin composition and the polyimide film. Therefore, the adhesion between the polyimide film and the cured composition is evaluated using the following criteria. "〇": Peel strength exceeds 0.2 kgf / cm. "×": The peel strength is less than 0.2 kgf / cm.

[0235] [Determination of warping] After peeling off the protective film from the resin sheets prepared in the examples and comparative examples, the resin composition was laminated onto a 12-inch wafer (775 μm thick) using a batch vacuum pressure laminator (Nikko-materials CVP700 2-stage build-up laminator) to form a 50 μm thick resin composition layer. The layer was then thermocured at 170°C for 240 minutes. The support was then peeled off to obtain a sample substrate containing a silicon wafer and a cured resin composition layer. The warpage of the sample substrate at 25°C was measured using a TherMoiré measuring apparatus (Akorometrix Thermoire AXP). The measurements were performed according to JEITA EDX-7311-24 specification. Specifically, a virtual plane calculated by the minimum flatness method of all data of the substrate surface in the measurement area is used as the reference plane, and the warping amount is obtained by using the difference between the minimum and maximum values ​​in the vertical direction from the reference plane.

[0236] [result] The results of the above embodiments and comparative examples are shown in the following table. In the following table, the amounts of each component represent the amounts of non-volatile components. Also, the abbreviations in the following table have the following meanings. T 900: The transmittance of light at a wavelength of 900 nm is measured when the thickness of the hardened resin composition is 50 μm. T 550: The transmittance of light at a wavelength of 550 nm is measured when the thickness of the cured resin composition is 50 μm. T 700: The transmittance of light at a wavelength of 700 nm is measured when the thickness of the cured resin composition is 50 μm. T 800: The transmittance of light at a wavelength of 800 nm is measured when the thickness of the hardened resin composition is 50 μm. T(40μm / 900nm): The transmittance of light at a wavelength of 900nm is measured when the thickness of the cured resin composition is 40μm. T(100μm / 900nm): The transmittance of light at a wavelength of 900nm is measured when the thickness of the hardened resin composition is 100μm. T(40μm / 550nm): The transmittance of light at a wavelength of 550nm is measured when the thickness of the cured resin composition is 40μm. T(100μm / 550nm): The transmittance of light at a wavelength of 550nm is measured when the thickness of the hardened resin composition is 100μm.

[0237]

[0238] 100: Semiconductor wafer packaging 110: Semiconductor wafers 120: Sealing layer 130: Rewiring Forming Layer 140: Rewiring 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, wherein the resin composition comprises (A) a thermosetting resin, (B) an inorganic filler, and (C) an elastomer, wherein the specific surface area of ​​the inorganic filler is 3.0 m² / g or more, the thickness of the resin composition layer is 20 μm or more and 100 μm or less, and the tensile modulus of the cured product obtained by curing the resin composition is 5 GPa or less.

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

3. The resin sheet of claim 1, wherein (C) the elastomer has one or more structures selected from polybutadiene and polysiloxane structures.

4. The resin sheet of claim 1, wherein the average particle size of the inorganic filler (B) is less than 1.5 μm.

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

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

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

8. The resin sheet of claim 5, wherein (A-1) epoxy resin comprises an epoxy resin containing a naphthalene ring.

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

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

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

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

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

14. A printed wiring board having a solder resist layer formed by a hardened resin composition layer of a resin sheet as claimed in any one of claims 1 to 13.

15. A semiconductor wafer package comprising a solder resist layer formed by a hardened resin composition layer of a resin sheet as claimed in any one of claims 1 to 13.

16. A semiconductor device comprising a printed wiring board as claimed in claim 14.

17. A semiconductor device comprising a semiconductor wafer package as claimed in claim 15.

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