Resin composition, prepreg, film with resin, metal foil with resin, metal-clad laminate, and printed wiring board

Abstract

The present disclosure provides a resin composition, a prepreg, a film having a resin, a metal foil having a resin, a metal-clad laminate, and a printed wiring board. The resin composition includes an epoxy compound, a maleimide compound, a phenolic compound, a core-shell rubber, and an inorganic filler. And the maleimide compound has an N-phenyl maleimide structure. The maleimide compound is contained in a range of 10 parts by mass to at least 40 parts by mass with respect to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound, and the phenolic compound.

Description

[0001] This application is a divisional application of an application with an international filing date of November 15, 2019, an international application number of PCT / JP2019 / 044794, a national application number of 201980071424.8, and an invention name of “Resin composition, prepreg, film with resin, metal foil with resin, metal-clad laminate and printed wiring board”. Technical Field

[0002] The present disclosure generally relates to a resin composition, a prepreg, a film with a resin, a metal foil sheet with a resin, a metal-clad laminate, and a printed wiring board. More specifically, the present disclosure relates to a resin composition containing an epoxy compound, a prepreg, a film with a resin, a metal foil sheet with a resin, a metal-clad laminate, and a printed wiring board. Background Art

[0003] Printed wiring boards are widely used in various fields, including electronic equipment, communication equipment and computers. Recently, small-sized mobile electronic devices such as mobile communication equipment and laptop personal computers (PCs) have significantly and rapidly improved their functionality, improved their performance, and reduced their thickness and size. In order to catch up with these trends, for the printed wiring boards used in these products, the demand for even reducing the characteristic size of their conductor lines, implementing their conductor lines with multilayers and reduced thickness, and further improving their performance in terms of, for example, mechanical properties is growing. In particular, as the thickness of the printed wiring board decreases, the semiconductor package (semiconductor device) formed by mounting a semiconductor chip on the printed wiring board is more and more likely to warp, thereby increasing the possibility of causing installation failures.

[0004] Patent document 1 discloses a semiconductor device formed by mounting a semiconductor element on a printed wiring board. The printed wiring board is obtained by subjecting a metal-clad laminate to a circuit forming process. The metal-clad laminate has two metal foil sheets, which are respectively arranged on the two surfaces of an insulating layer comprising an epoxy resin composition and a fiber substrate. The epoxy resin composition contains an epoxy resin, a bismaleimide compound and an inorganic filler. In addition, the hysteresis degree of the dimensional change of the metal-clad laminate in the range of 30°C to 260°C is within a predetermined range. In this way, according to patent document 1, the warping of the metal-clad laminate is reduced.

[0005] However, the metal-clad laminate of Patent Document 1 cannot sufficiently reduce the warpage of the semiconductor package.

[0006] Therefore, in order to reduce the warpage of the semiconductor package, the present inventors paid special attention to the thermal expansion coefficient and the glass transition temperature (Tg) of the printed wiring board.

[0007] In addition, in order to interconnect a plurality of conductor line patterns on two or more different layers of a printed wiring board, holes are drilled or laser cut through the printed wiring board. When these holes are drilled, resin stains are left on the inner walls of the holes. Therefore, a desmearing process is required to remove the resin stains. The desmearing process is performed using permanganate such as potassium permanganate.

[0008] However, if the resin smear is excessively removed by the desmear process (i.e., if the desmear etching rate is excessive), for example, the hole will be deformed and the copper foil will peel off, thereby possibly causing a significant decrease in the conductivity reliability of the printed wiring board. Therefore, there is an increasing demand for reducing the desmear etching rate, i.e., improving the desmear resistance.

[0009] Reference List

[0010] Patent Literature

[0011] Patent Document 1: JP 2015-063040 A Summary of the invention

[0012] Therefore, an object of the present disclosure is to provide a resin composition, a prepreg, a film with a resin, a metal foil sheet with a resin, a metal-clad laminate and a printed wiring board, all of which contribute to obtaining a substrate having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent stain resistance.

[0013] The resin composition according to one aspect of the present disclosure contains an epoxy compound, a phenolic compound, a maleimide compound, a core-shell rubber and an inorganic filler. The maleimide compound has an N-phenylmaleimide structure. Relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound, the content of the maleimide compound is in the range of 10 parts by mass to less than 40 parts by mass.

[0014] A prepreg according to another aspect of the present disclosure includes: a base material; and a resin layer made of a semi-cured product of a resin composition impregnated into the base material.

[0015] A film with a resin according to still another aspect of the present disclosure includes: a resin layer made of a semi-cured product of a resin composition; and a supporting film supporting the resin layer thereon.

[0016] A metal foil sheet with resin according to still another aspect of the present disclosure includes: a resin layer made of a semi-cured product of a resin composition; and a metal foil sheet combined with the resin layer.

[0017] A metal clad laminate according to still another aspect of the present disclosure includes: an insulating layer made of a cured product of a resin composition or a cured product of a prepreg; and at least one metal layer formed on one surface or both surfaces of the insulating layer.

[0018] A printed wiring board according to still another aspect of the present disclosure includes: an insulating layer made of a cured product of a resin composition or a cured product of a prepreg; and at least one conductor wiring layer formed on one surface or both surfaces of the insulating layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic cross-sectional view of a prepreg according to an exemplary embodiment of the present disclosure;

[0020] Figure 2 A is a schematic cross-sectional view of a film with a resin (and without a protective film) according to an exemplary embodiment of the present disclosure;

[0021] Figure 2 B is a schematic cross-sectional view of a film with a resin (and with a protective film) according to an exemplary embodiment of the present disclosure;

[0022] Figure 3 is a schematic cross-sectional view of a metal foil sheet with resin according to an exemplary embodiment of the present disclosure;

[0023] Figure 4 is a schematic cross-sectional view of a metal-clad laminate according to an exemplary embodiment of the present disclosure; and

[0024] Figure 5 is a schematic cross-sectional view of a printed wiring board according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] (1) Summary

[0026] The resin composition according to an exemplary embodiment of the present disclosure contains an epoxy compound, a phenolic compound, a maleimide compound, a core-shell rubber and an inorganic filler. The maleimide compound has an N-phenylmaleimide structure. Relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound, the content of the maleimide compound is in the range of 10 parts by mass to less than 40 parts by mass.

[0027] When the resin composition contains a specific maleimide compound of a specific content as described above, a substrate with a high glass transition temperature (Tg) and excellent desmear resistance can be obtained. When the glass transition temperature (Tg) is high, heat resistance can be improved. In addition, when the desmear resistance is excellent, the change in the diameter of the through hole before and after the desmear process can be reduced. This makes it possible to further reduce the diameter of the through hole, and to ensure sufficient electrical insulation properties when multiple through holes are densely arranged. Therefore, the conductor line can be formed more finely.

[0028] In addition, when the resin composition contains the core-shell type rubber and the inorganic filler, a substrate having a low thermal expansion coefficient can be obtained.

[0029] That is, this embodiment enables a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg) and excellent desmear resistance to be obtained. Therefore, using the substrate obtained in this manner as a packaging substrate will effectively contribute to reducing the warpage of the semiconductor package.

[0030] (2) Details

[0031] (2.1) Resin composition

[0032] The resin composition according to this embodiment can be used as a substrate material. Specific examples of substrate materials include prepregs, films with resins, metal foil sheets with resins, metal-clad laminates, and printed wiring boards. However, these are only examples and should not be construed as restrictive.

[0033] The resin composition contains an epoxy compound, a phenolic compound, a maleimide compound, a core-shell rubber and an inorganic filler. Therefore, the resin composition can have thermosetting properties. The resin composition can also contain a curing accelerator. Optionally, the resin composition can also contain an additive.

[0034] For example, the resin composition can be prepared in the following manner: Specifically, an epoxy compound, a phenolic compound, a maleimide compound, a core-shell rubber and an inorganic filler are mixed together, the resulting mixture is diluted with a suitable solvent, and then the mixture is stirred until it has a uniform concentration.

[0035] Next, each constituent component of the resin composition will be described.

[0036] (2.1.1) Epoxides

[0037] Epoxides are prepolymers and are compounds having at least two epoxy groups per molecule. Generally speaking, the term "resin" refers to two different types of resins, namely, resins that are materials that have not yet been cross-linked (such as epoxy compounds) and resins that are cross-linked products (final products). As used herein, "resin" refers essentially to the former type of resin.

[0038] Specific examples of epoxy compounds include: bisphenol epoxy resin, novolac epoxy resin, biphenyl epoxy resin, xylene epoxy resin, aryl alkylene epoxy resin, naphthalene epoxy resin, naphthalene skeleton modified epoxy resin, triphenylmethane epoxy resin, anthracene epoxy resin, dicyclopentadiene epoxy resin, norbornene epoxy resin, fluorene epoxy resin and flame retardant epoxy resin obtained by halogenating any of these epoxy resins. However, these are only examples and should not be construed as restrictive. The resin composition may contain only one type of epoxy compound, or may contain two or more types of epoxy compounds, whichever is suitable.

[0039] Specific examples of the bisphenol type epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin. However, these are merely examples and should not be construed as limitative.

[0040] Specific examples of the novolac type epoxy resin include phenol novolac type epoxy resin and cresol novolac type epoxy resin. However, these are merely examples and should not be construed as limiting.

[0041] Specific examples of the arylalkylene epoxy resin include phenol aralkyl epoxy resin, biphenyl aralkyl epoxy resin, biphenyl novolac epoxy resin, biphenyl dimethylene epoxy resin, trisphenol methane novolac epoxy resin and tetramethyl biphenyl epoxy resin. However, these are only examples and should not be construed as limiting.

[0042] Specific examples of the naphthalene skeleton-modified epoxy resin include naphthalene skeleton-modified cresol novolac type epoxy resin, naphthalene diol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, methoxy naphthalene-modified cresol novolac type epoxy resin and methoxy naphthalene dimethylene type epoxy resin. However, these are only examples and should not be construed as limiting.

[0043] The epoxy compound suitably includes an epoxy compound having at least one of a naphthalene skeleton or a biphenyl skeleton.

[0044] The epoxy compound having a naphthalene skeleton can have excellent heat resistance, moisture resistance and flame retardancy. This enables the resin composition to exhibit excellent performance in these aspects. As used herein, the phrase "excellent heat resistance" means that the glass transition temperature (Tg) is high.

[0045] The epoxy compound having a biphenyl skeleton may have a crystalline property at room temperature. Such an epoxy compound is a solid resin, but may have a viscosity as low as a liquid resin when melted. Therefore, even if the resin composition is filled with an inorganic filler at a high percentage, the resin composition may still maintain excellent fluidity when melted.

[0046] In addition, the epoxy compound having a biphenyl skeleton can have excellent flame retardancy, heat resistance and adhesiveness. This makes it possible to obtain a resin composition that exhibits excellent performance in these aspects.

[0047] The epoxy equivalent of the epoxy compound is suitably in the range of 150 g / eq to 350 g / eq.

[0048] (2.1.2) Phenolic compounds

[0049] Phenolic compounds are prepolymers that can react with epoxy compounds. Phenolic compounds are the products of the condensation reaction between phenol and aldehyde.

[0050] The specific example of phenolic compound comprises biphenyl aralkyl type phenolic resin, phenyl aralkyl type phenolic resin, novolac type phenolic resin, cresol novolac type phenolic resin, bisphenol A novolac type phenolic resin, naphthalene type phenolic resin, tetraphenol type phenolic resin and phosphorus modified phenolic resin. However, these are only examples and should not be construed as restrictive. Resin combination can contain only one type of phenolic compound, or can contain two or more types of phenolic compounds, whichever is suitable.

[0051] The phenolic compound suitably includes a phenolic compound having at least one of a naphthalene skeleton or a biphenyl skeleton.

[0052] The phenol compound having a naphthalene skeleton can have the same properties as the epoxy compound having a naphthalene skeleton. Therefore, a resin composition having excellent heat resistance, moisture resistance and flame retardancy can be obtained.

[0053] The phenol compound having a biphenyl skeleton may have the same properties as the epoxy compound having a biphenyl skeleton. Therefore, even if the resin composition is filled with an inorganic filler at a high percentage, the resin composition may maintain excellent fluidity when melted.

[0054] In addition, the phenolic compound having a biphenyl skeleton can have excellent flame retardancy, heat resistance and adhesiveness. This makes it possible to obtain a resin composition that exhibits excellent performance in these aspects.

[0055] The phenolic compound is suitably a phosphorus-containing phenolic compound. The phosphorus-containing phenolic compound contains phosphorus and can act as a flame retardant. Specifically, when exposed to flames, phosphorus is successively decomposed into phosphoric acid, metaphosphoric acid and polymetaphosphoric acid, and the phosphoric acid layer thus produced can form a non-volatile protective layer to block air. In addition, the polymetaphosphoric acid thus produced carbonizes organic matter by strong dehydration, and the carbonized film thus formed can block air. Therefore, a resin composition with excellent flame retardancy can be obtained.

[0056] Generally, flame retardants can be classified into additive and reactive types. Phosphorus-containing phenolic compounds are not additive, but reactive. That is, phosphorus-containing phenolic compounds have functional groups such as hydroxyl groups and are chemically bonded to epoxy compounds through chemical reactions. Therefore, not only flame retardancy can be imparted to the resin composition, but also stain resistance can be imparted to the resin composition. Additive flame retardants may cause a decrease in stain resistance and should not be included in the resin composition.

[0057] The phosphorus-containing phenolic compound preferably has a structure represented by the following chemical formula (4) in its molecule, even though this is only an example and should not be construed as limiting. In addition, the phosphorus-containing phenolic compound preferably has a bisphenol A type structure in its molecule. Such a phosphorus-containing phenolic compound having a structure represented by the following chemical formula (4) and a bisphenol A type structure can be, for example, "XZ92741.00" produced by the Dow Chemical Company Japan.

[0058] (4)

[0059] Where * represents a chemical bond.

[0060] Relative to 100 parts by mass of epoxy compound, maleimide compound and phenolic compound total amount, the content of phenolic compound is suitably in the range of 10 parts by mass to 30 parts by mass. The content of phenolic compound is set to more than 10 parts by mass to reduce the possibility of causing glass transition temperature (Tg) to decline or insufficient curing. This reduces the percentage of unreacted resin, thereby suppressing the decline in stain resistance. On the other hand, the content of phenolic compound is set to less than 30 parts by mass to reduce the increase of polar groups such as hydroxyl groups, and suppress the decline in stain resistance.

[0061] The resin composition may contain both a phosphorus-containing phenolic compound and a non-phosphorus-containing phenolic compound. If the resin composition contains both of these compounds, the mass ratio of (phosphorus-containing phenolic compound / non-phosphorus-containing phenolic compound) is suitably in the range of 15 / 100 to 50 / 100.

[0062] (2.1.3) Maleimide compounds having an N-phenylmaleimide structure

[0063] The maleimide compound with N-phenylmaleimide structure is a compound that can react with epoxy compounds and phenolic compounds. The maleimide compound with N-phenylmaleimide structure has at least one N-phenylmaleimide structure. In the following description, unless otherwise specified, "maleimide compound with N-phenylmaleimide structure" is referred to as "maleimide compound" hereinafter. The N-phenylmaleimide structure is represented by the following chemical formula (3). The maleimide compound effectively contributes to improving the Tg of the cured product of the resin composition.

[0064] (3)

[0065] Here, R represents groups which are the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and * represents a chemical bond, the number of which may be only one.

[0066] Note that the number of carbon atoms in the alkyl group represented by R in formula (3) is not limited to any specific value. The alkyl group may have a straight chain or a branched chain, whichever is suitable. Specific examples of the alkyl group represented by R include alkyl groups having one to three carbon atoms.

[0067] The maleimide compound suitably has at least one biphenyl structure. The maleimide compound with a biphenyl structure can have the same properties as an epoxy compound with a biphenyl skeleton. Therefore, even if the resin composition is filled with an inorganic filler at a high percentage, the resin composition can still maintain excellent fluidity when melted. In addition, a resin composition with excellent flame retardancy and other beneficial properties can be obtained.

[0068] The maleimide compound suitably includes a compound represented by the following chemical formula (1). This maleimide compound has a biphenyl skeleton. Therefore, even if the resin composition is filled with an inorganic filler at a high percentage, the resin composition can still maintain excellent fluidity when melted. In addition, a resin composition with excellent flame retardancy and other beneficial properties can be obtained.

[0069] (1)

[0070] wherein R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

[0071] Note that the number of carbon atoms in the alkyl group represented by R in formula (3) is not limited to any specific value. The alkyl group may have a straight chain or a branched chain, whichever is suitable. Specific examples of the alkyl group represented by R include alkyl groups having one to three carbon atoms.

[0072] The maleimide compound includes a compound represented by the following chemical formula (2). The maleimide compound enables the cured product of the resin composition to have a high Tg, thereby improving heat resistance. In addition, the maleimide compound can also increase the elastic modulus of the cured product of the resin composition.

[0073] (2)

[0074] wherein R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

[0075] Note that the number of carbon atoms in the alkyl group represented by R in the chemical formula (2) is not limited to any specific value. The alkyl group may have a straight chain or a branched chain, whichever is suitable. Specific examples of the alkyl group represented by R include alkyl groups having one to two carbon atoms.

[0076] The resin composition may contain only one type of maleimide compound having an N-phenylmaleimide structure, or may contain two or more types of maleimide compounds each having an N-phenylmaleimide structure, either of which is suitable. Specific examples of maleimide compounds include phenylmethane maleimide, 4,4′-diphenylmethane bismaleimide, metaphenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethane bismaleimide and 4-methyl-1,3-phenylene bismaleimide. However, these are only examples and should not be construed as limiting. In addition, the maleimide compound may be partially amine-modified and / or silicone-modified in its molecule.

[0077] The content of the maleimide compound having an N-phenylmaleimide structure is in the range of 10 parts by mass to less than 40 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound. If the content of the maleimide compound is less than 10 parts by mass, the glass transition temperature (Tg) may be reduced. On the other hand, if the content of the maleimide compound is equal to or more than 40 parts by mass, the stain resistance may be reduced.

[0078] (2.1.4) Core-shell rubber

[0079] The core-shell rubber can act as an impact modifier. The core-shell rubber can be combined with an inorganic filler to reduce the thermal expansion of the cured product of the resin composition. The core-shell rubber includes a core and a shell. The core is a particle-shaped rubber. The shell is a grafted layer and covers the core.

[0080] The core suitably comprises one or more materials selected from the group consisting of the following: (meth) acrylic acid polymers, (meth) acrylic acid ester polymers, olefinic compound polymers, polybutadiene and silicone resin. Shell suitably comprises one or more materials selected from the group consisting of the following: styrene-acrylonitrile copolymers, (meth) acrylic acid polymers, polybutadiene and silicone resin. Such core-shell rubber can give the cured product of resin combination heat resistance and low temperature impact resistance. An example of such core-shell rubber can be silicone resin-acrylic acid composite rubber. In silicone resin-acrylic acid composite rubber, core is silicone resin / acrylic acid polymer, and shell is styrene acrylonitrile copolymer. As used herein, "(meth) acrylic acid" refers to at least one of acrylic acid or methacrylic acid.

[0081] Specific examples of the core-shell rubber include: products named "S-2001", "S-2006", "S-2501", "S-2030", "S-2100", "S-2200", "SRK200A", "SX-006" and "SX-005" produced by Mitsubishi Chemical Corporation; products named "AC3816", "AC3816N", "AC3832", "AC4030", "AC3364" and "IM101" produced by Aica Kogyo Co., Ltd.; products named "MX-217", "MX-153", "MX-960", "MR-01", "M-511" and "M-521" produced by Kaneka Corporation; products named "EXL-2655", "TMS-2670J" and "TMS-2670S" produced by the Dow Chemical Company Japan; and products named "EXL-2655", "TMS-2670J" and "TMS-2670S" produced by Nisshin Chemical Co., Ltd. Ltd. produce products under the names "R-200" and "R-170S". However, these are merely examples and should not be construed as limiting.

[0082] The average particle size of the core-shell rubber is suitably less than 1 μm. Such core-shell rubber is preferred for the following reasons. Specifically, sometimes an insulating layer of a resin composition is formed on the surface of a printed wiring board with a conductor track. In such a case, if the resin composition contains a core-shell rubber with such a small average particle size, the gap between the adjacent parts of the conductor track can be more easily filled. This is particularly effective for the case where a fine line conductor pattern (i.e., so-called "fine pattern") is densely formed on a printed wiring board. The same statement is not only applicable to the case where the insulating layer is provided in the form of a resin composition, but also applicable to the case where the insulating layer is provided in the form of a prepreg, a film with a resin, or a metal foil sheet with a resin. The lower limit of the average particle size of the core-shell rubber is not limited to any specific value, but for example can be 0.1 μm. As used herein, "average particle size" refers to the particle size in the case where the integral value is 50% in the particle size distribution measured by a laser diffraction scattering method.

[0083] The content of the core-shell rubber is suitably in the range of 10 to 50 parts by mass, and more suitably in the range of 17.5 to 40 parts by mass, relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound, and the phenolic compound. The content of the core-shell rubber is set to more than 10 parts by mass so that the thermal expansion coefficient can be reduced. The content of the core-shell rubber is set to less than 50 parts by mass to reduce the possibility of causing a decrease in stain resistance, a decrease in glass transition temperature (Tg), a decrease in adhesion to metal foil sheets (particularly, such as copper foil), and a decrease in flame retardancy.

[0084] (2.1.5) Inorganic fillers

[0085] The inorganic filler helps to reduce the thermal expansion of the cured product of the resin composition in combination with the core-shell rubber.

[0086] Specific examples of inorganic fillers include silica such as fused silica and crystalline silica, talc, boehmite, magnesium hydroxide, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, clay and mica. However, these are only examples and should not be construed as limiting. The resin composition may contain only one type of inorganic filler, or may contain two or more types of inorganic fillers, whichever is suitable.

[0087] The inorganic filler suitably comprises one or more types of compounds selected from the group consisting of: silicon dioxide, talc, boehmite, magnesium hydroxide and aluminum hydroxide. These inorganic fillers are particularly effective in helping to reduce the thermal expansion of the cured product of the resin composition. In particular, the resin composition suitably contains silicon dioxide and magnesium hydroxide.

[0088] The average particle size of the inorganic filler is suitably in the range of 0.1 μm to 3.0 μm, and more suitably in the range of 0.5 μm to 1.5 μm.

[0089] The content of the inorganic filler is suitably in the range of 25 to 200 parts by mass, and more suitably in the range of 50 to 150 parts by mass, relative to 100 parts by mass of the total amount of the epoxy compound, the phenol compound and the maleimide compound.

[0090] If the resin composition contains silica and magnesium hydroxide as inorganic fillers, the mass ratio of silica to magnesium hydroxide (silicon dioxide / magnesium hydroxide) is suitably in the range of 50 / 2.5 to 150 / 2.5.

[0091] (2.1.6) Curing accelerator

[0092] Unless the advantage of this embodiment is damaged, the type and content of the curing accelerator added are not limited to any specific type and content. The specific example of curing accelerator includes imidazole compounds such as 2-ethyl-4-methylimidazole, amine compounds, mercaptan compounds and organic acid metal salts such as metal soaps. However, these are only examples and should not be construed as restrictive.

[0093] (2.1.7) Additives

[0094] Unless the advantages of this embodiment are impaired, the type and content of the additive used are not limited to any specific type and content. Specific examples of additives include thermoplastic resins, flame retardants, colorants and coupling agents. However, these are only examples and should not be interpreted as limiting.

[0095] (2.2) Prepreg

[0096] Figure 1 The prepreg 1 according to this embodiment is shown. The prepreg 1 has a shape of a sheet or film as a whole. The prepreg 1 can be used as a material for the metal-clad laminate 4, as a material for the printed wiring board 5, and for forming a printed wiring board 5 having multiple layers (by an additive method).

[0097] The prepreg 1 includes a base material 11 and a resin layer 10. The resin layer 10 is made of a semi-cured product of a resin composition impregnated into the base material 11.

[0098] Single prepreg 1 includes at least one substrate 11. The thickness of substrate 11 is not limited to any specific value, but for example can be in the range of 8 μm to 100 μm. Specific examples of substrate 11 include woven fabrics and nonwoven fabrics. Specifically, woven fabrics can be, but not necessarily, glass cloth. Nonwoven fabrics can be, but not necessarily, glass nonwoven fabrics. Glass cloth and glass nonwoven fabrics are formed by glass fibers, but can also be formed by reinforcing fibers other than glass fibers. Any type of glass can be used without restriction to form glass fibers. Examples of glass include E glass, T glass, S glass, Q glass, UT glass, NE glass and L glass. Specific examples of reinforcing fibers include aramid fibers, liquid crystal polyester fibers, poly (p-phenylene benzobisoxazole) (PBO) fibers and polyphenylene sulfide (PPS) resin fibers. However, these are only examples and should not be interpreted as limiting.

[0099] Semi-cured product refers to a resin composition in a semi-cured state in this article. As used herein, "semi-cured state" refers to a state in the intermediate stage (stage B) of the curing reaction. The intermediate stage is a stage between the varnish state stage (stage A) and the cured state stage (stage C). When heated, the prepreg 1 melts once. Afterwards, the prepreg 1 is fully cured and converted into a cured product. The cured product of the prepreg 1 can constitute the insulating layer of the substrate.

[0100] The thickness of the prepreg 1 is not limited to any specific value, but is preferably 120 μm or less, more preferably 100 μm or less, even more preferably 60 μm or less, and most preferably 40 μm or less. This enables the insulating layer to have a reduced thickness, thereby also reducing the overall thickness of the substrate. The thickness of the prepreg 1 is preferably 10 μm or more.

[0101] The resin layer 10 of the prepreg 1 is made of the resin composition according to this embodiment, thereby enabling a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg), and excellent stain removal resistance to be obtained.

[0102] (2.3) Film with resin

[0103] Figure 2 A shows a film 2 with resin according to this embodiment. The film 2 with resin has a shape of a film or sheet as a whole. The film 2 with resin includes a resin layer 20 and a support film 21. The film 2 with resin can be used to form a printed wiring board 5 with multiple layers (by an accumulation method).

[0104] The resin layer 20 is formed of a semi-cured product of a resin composition. When heated, the semi-cured product can be converted into a cured product. In this way, the resin layer 20 can form an insulating layer.

[0105] The thickness of the resin layer 20 is not limited to any specific value, but is preferably 120 μm or less, more preferably 100 μm or less, even more preferably 60 μm or less, and most preferably 40 μm or less. This enables the insulating layer to have a reduced thickness, thereby also reducing the overall thickness of the substrate. The thickness of the resin layer 20 is preferably 10 μm or more.

[0106] The support film 21 supports the resin layer 20 thereon. Supporting the resin layer 20 in this manner enables the resin layer 20 to be handled more easily.

[0107] For example, the support film 21 may be, but is not necessarily, an electrical insulating film. Specific examples of the support film 21 include polyethylene terephthalate (PET) films, polyimide films, polyester films, polyoxalyl urea films, polyetheretherketone films, polyphenylene sulfide films, polyaramide films, polycarbonate films, and polyacrylate films. However, these are only examples, and the support film 21 is not necessarily one of these films.

[0108] A release agent layer (not shown) may be provided on the surface of the support film 21 for supporting the resin layer 20. The support film 21 may be peeled off from the resin layer 20 through the release agent layer as needed. After the resin layer 20 has been cured to form an insulating layer, the support film 21 is suitably peeled off from the insulating layer.

[0109] Despite Figure 2 In the example shown in A, one surface of the resin layer 20 is covered with a support film 21, but Figure 2 As shown in FIG. 2B , the other surface of the resin layer 20 may be protected by a protective film 22. Covering both surfaces of the resin layer 20 in this way enables even easier handling of the resin layer 20. This also reduces the likelihood of foreign particles attaching to the resin layer 20.

[0110] For example, the protective film 22 may be, but not necessarily, an electrical insulating film. Specific examples of the protective film 22 include polyethylene terephthalate (PET) films, polyolefin films, polyester films, and polymethylpentene films. However, these are only examples, and the protective film 22 is not necessarily one of these films.

[0111] A release agent layer (not shown) may be provided on the surface of the protective film 22 located above the resin layer 20. The protective film 22 may be peeled off from the resin layer 20 through the release agent layer as needed.

[0112] The resin layer 20 of the film 2 with resin is formed of the resin composition according to this embodiment, thereby enabling a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg), and excellent resistance to stain removal to be obtained.

[0113] (2.4) Metal foil sheet with resin

[0114] Figure 3 The metal foil sheet 3 with resin according to this embodiment is shown. The metal foil sheet 3 with resin has a shape of a film or sheet as a whole. The metal foil sheet 3 with resin includes a resin layer 30 and a metal foil sheet 31. The metal foil sheet 3 with resin can be used to form a printed wiring board 5 with multiple layers (by an additive method).

[0115] The resin layer 30 is formed of a semi-cured product of a resin composition. When heated, the semi-cured product can be converted into a cured product. In this way, the resin layer 30 can form an insulating layer.

[0116] The thickness of the resin layer 30 is not limited to any specific value, but is preferably 120 μm or less, more preferably 100 μm or less, even more preferably 60 μm or less, and most preferably 40 μm or less. This enables the insulating layer formed by curing the resin layer 30 to have a reduced thickness, thereby also reducing the overall thickness of the substrate. The thickness of the resin layer 30 is preferably 10 μm or more.

[0117] The resin layer 30 is bonded to the metal foil sheet 31. The metal foil sheet 31 may be specifically but not necessarily a copper foil sheet. For example, the metal foil sheet 31 may be patterned into a conductor line by etching away unnecessary portions using a subtractive process.

[0118] The thickness of the metal foil sheet 31 is not limited to any specific value, but is suitably 35 μm or less, and more suitably 18 μm or less. The thickness of the metal foil sheet 31 is suitably 5 μm or more.

[0119] Optionally, the metal foil sheet 31 can be configured as an extremely thin metal foil sheet (such as an extremely thin copper foil sheet) of a so-called "extremely thin metal foil sheet with a carrier". The extremely thin metal foil sheet with a carrier has a three-layer structure. That is, the extremely thin metal foil sheet with a carrier includes: a carrier; a peelable layer arranged on the surface of the carrier; and an extremely thin metal foil sheet arranged on the surface of the peelable layer. The extremely thin metal foil sheet is too thin to be easily handled alone, and is naturally thinner than the carrier. The carrier is a metal foil sheet (such as a copper foil sheet) that plays the role of supporting the extremely thin metal foil sheet. The extremely thin metal foil sheet with a carrier is relatively thicker and thick enough to be easily handled. The thickness of the extremely thin metal foil sheet and the carrier is not limited to any specific value. For example, the thickness of the extremely thin metal foil sheet can be, for example, in the range of 1 μm to 10 μm, and the thickness of the carrier can be in the range of 18 μm to 35 μm. The extremely thin metal foil sheet can be peeled off from the carrier as needed.

[0120] When using an extremely thin metal foil sheet with a carrier, the metal foil sheet 3 with resin can be manufactured in the following manner. Specifically, a resin composition is applied to the surface of an extremely thin metal foil sheet of an extremely thin metal foil sheet with a carrier and heated to form a resin layer 30. Afterwards, the carrier is peeled off from the extremely thin metal foil sheet. The extremely thin metal foil sheet is bonded to the surface of the resin layer 30 as a metal foil sheet 31. The peelable layer is suitably peeled off together with the carrier and should not be left on the surface of the extremely thin metal foil sheet. Nevertheless, even if any part of the peelable layer is left on the surface of the extremely thin metal foil sheet, the residual part of the peelable layer can also be easily removed. The extremely thin metal foil sheet bonded to the surface of the resin layer 30 can be used as a seed layer in a modified semi-additive process (MSAP). Conductor circuits can be formed by electrolytic plating process to the seed layer.

[0121] The resin layer 30 of the metal foil sheet 3 with resin is formed of the resin composition according to this embodiment, thereby enabling a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg), and excellent desmear resistance to be obtained.

[0122] (2.5) Metal-clad laminate

[0123] Figure 4 A metal-clad laminate 4 according to this embodiment is shown. The metal-clad laminate 4 includes an insulating layer 40 and a metal layer 41. The metal-clad laminate 4 can be used as a material of a printed wiring board 5, for example.

[0124] The insulating layer 40 is made of a cured product of a resin composition or a cured product of a prepreg 1. Figure 4 The illustrated example includes a single substrate 42 , but the insulating layer 40 may include more than two substrates 42 .

[0125] The thickness of the insulating layer 40 is not limited to any specific value. The smaller the thickness of the insulating layer 40, the more effectively the insulating layer 40 contributes to reducing the thickness of the substrate. The thickness of the insulating layer 40 is suitably 120 μm or less, more suitably 100 μm or less, even more suitably 60 μm or less, and most suitably 40 μm or less. The thickness of the insulating layer 40 is suitably 10 μm or more, and more suitably 15 μm or more.

[0126] The metal layer 41 is formed on one surface or both surfaces of the insulating layer 40. For example, the metal layer 41 may be, but not necessarily, a metal foil sheet. For example, the metal foil sheet may be, but not necessarily, a copper foil sheet. Figure 4In the example shown, the metal layer 41 is provided on both surfaces of the insulating layer 40, but the metal layer 41 may be provided on only one surface of the insulating layer 40. The metal-clad laminate 4 including the metal layer 41 on both surfaces of the insulating layer 40 is a double-sided metal-clad laminate. The metal-clad laminate 4 including the metal layer 41 on only one side of the insulating layer 40 is a single-sided metal-clad laminate.

[0127] The thickness of the metal layer 41 is not limited to any specific value, but is desirably 35 μm or less, and more desirably 18 μm or less. The thickness of the metal layer 41 is desirably 5 μm or more.

[0128] Optionally, the metal layer 41 can be formed by an extremely thin metal foil sheet of an extremely thin metal foil sheet with a carrier. When an extremely thin metal foil sheet with a carrier is used, the metal-clad laminate 4 can be manufactured in the following manner. Specifically, an extremely thin metal foil sheet with a carrier can be stacked and formed on one or both surfaces of a single prepreg 1. Alternatively, a plurality of prepregs 1 can be stacked on each other, and an extremely thin metal foil sheet with a carrier can be stacked and formed on one or both surfaces of a stack of a plurality of prepregs 1. In this case, an extremely thin metal foil sheet of an extremely thin metal foil sheet with a carrier is stacked on the surface of the prepreg 1. After the stack has been formed, the carrier is peeled off from the extremely thin metal foil sheet. The extremely thin metal foil sheet is combined as a metal layer 41 with the surface of an insulating layer 40, which is a cured product of the prepreg 1. The peelable layer is suitably peeled off together with the carrier, and should not be left on the surface of the extremely thin metal foil sheet. Nevertheless, even if any part of the peelable layer remains on the surface of the ultra-thin metal foil sheet, the remaining part of the peelable layer can be easily removed. The ultra-thin metal foil sheet bonded to the surface of the insulating layer 40 can be used as a seed layer in a modified semi-additive process (MSAP). Conductor lines can be formed by performing an electrolytic plating process on the seed layer.

[0129] The insulating layer 40 of the metal-clad laminate 4 is formed of the resin composition according to this embodiment, thereby enabling a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg), and excellent desmear resistance to be obtained. The thermal expansion coefficient is preferably 10 ppm / K or less. The glass transition temperature (Tg) is preferably 250°C or more, and more preferably 260°C or more.

[0130] (2.6) Printed circuit board

[0131] Figure 5 A printed wiring board 5 according to this embodiment is shown. The printed wiring board 5 includes an insulating layer 50 and a conductor line 51. As used herein, a "printed wiring board" refers to a substrate to which electronic components have not been soldered and which includes only lines thereon.

[0132] The insulating layer 50 is made of a cured product of a resin composition or a cured product of the prepreg 1. The insulating layer 50 may be the same as the insulating layer 40 of the metal-clad laminate 4.

[0133] The conductor line 51 is formed on one surface or both surfaces of the insulating layer 50. Figure 5 , the conductor line layer 51 is formed on each of the two surfaces of the insulating layer 50. However, this is only an example and should not be construed as limiting. Alternatively, the conductor line 51 may be provided only on one surface of the insulating layer 50. The conductor line 51 may be formed by any method without limitation. Examples of methods for forming the conductor line 51 include a subtractive method, a semi-additive method (SAP), and a modified semi-additive method (MSAP).

[0134] The insulating layer 50 of the printed wiring board 5 is made of the resin composition according to this embodiment, thereby enabling a substrate having a low thermal expansion coefficient, a high glass transition temperature (Tg) and excellent desmear resistance to be obtained. Therefore, using the printed wiring board 5 as a packaging substrate will effectively contribute to reducing the warpage of the semiconductor package.

[0135] (3) Overview

[0136] As can be seen from the foregoing description of the embodiments, the present disclosure has the following aspects. In the following description, reference numerals are inserted in parentheses only to clarify the correspondence between the following aspects of the present disclosure and the constituent elements of the above exemplary embodiments.

[0137] The resin composition according to the first aspect contains an epoxy compound, a maleimide compound, a phenolic compound, a core-shell rubber and an inorganic filler. The maleimide compound has an N-phenylmaleimide structure. The content of the maleimide compound is in the range of 10 parts by mass to less than 40 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound.

[0138] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0139] In the resin composition according to the second aspect (which may be implemented in combination with the first aspect), the maleimide compound includes a maleimide compound further having a biphenyl structure.

[0140] This aspect enables the resin composition to maintain excellent fluidity during melting even if the resin composition is filled with an inorganic filler at a high percentage. In addition, this aspect also enables a resin composition having excellent flame retardancy and other beneficial properties to be obtained.

[0141] In the resin composition according to the third aspect (which may be implemented in combination with the second aspect), the maleimide compound includes a compound represented by the following chemical formula (1):

[0142] (1)

[0143] wherein R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

[0144] This aspect enables the resin composition to maintain excellent fluidity during melting even if the resin composition is filled with an inorganic filler at a high percentage. In addition, this aspect also enables a resin composition having excellent flame retardancy and other beneficial properties to be obtained.

[0145] In the resin composition according to the fourth aspect (which may be implemented in combination with the first aspect), the maleimide compound includes a compound represented by the following chemical formula (2):

[0146] (2)

[0147] wherein R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

[0148] This aspect enables the cured product of the resin composition to have a high Tg, thereby improving heat resistance.

[0149] In the resin composition according to the fifth aspect (which may be implemented in combination with any one of the first to fourth aspects), the epoxy compound includes an epoxy compound having at least one of a naphthalene skeleton or a biphenyl skeleton.

[0150] This aspect enables, when the resin composition comprises an epoxy compound having a naphthalene skeleton, a resin composition having excellent heat resistance, moisture resistance and flame retardancy to be obtained. In addition, this aspect also enables, when the resin composition comprises an epoxy compound having a biphenyl skeleton, excellent fluidity to be maintained during melting even when the resin composition is filled with an inorganic filler at a high percentage. In addition, this aspect also enables a resin composition having excellent flame retardancy and other beneficial properties to be obtained.

[0151] In the resin composition according to the sixth aspect (which may be implemented in combination with any one of the first to fifth aspects), the phenolic compound includes a phenolic compound having at least one of a naphthalene skeleton or a biphenyl skeleton.

[0152] This aspect enables, when the resin composition comprises a phenolic compound having a naphthalene skeleton, a resin composition having excellent heat resistance, moisture resistance and flame retardancy to be obtained. In addition, this aspect also enables, when the resin composition comprises a phenolic compound having a biphenyl skeleton, the resin composition to maintain excellent fluidity during melting even when the resin composition is filled with an inorganic filler at a high percentage. In addition, this aspect also enables a resin composition having excellent flame retardancy and other beneficial properties to be obtained.

[0153] In the resin composition according to the seventh aspect (which can be implemented in combination with any one of the first to sixth aspects), the content of the phenolic compound is in the range of 10 to 30 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound.

[0154] According to this aspect, setting the content of the phenolic compound to 10 parts by mass or more enables the glass transition temperature (Tg) to be reduced and the stain resistance to be reduced. In addition, setting the content of the phenolic compound to 30 parts by mass or less enables the stain resistance to be reduced.

[0155] In the resin composition according to the eighth aspect (which can be implemented in combination with any one of the first to seventh aspects), the core-shell rubber includes a core and a shell covering the core. The core comprises one or more substances selected from the group consisting of (meth) acrylic acid polymers, (meth) acrylic acid ester polymers, olefin compound polymers, polybutadiene and silicone resins. The shell comprises one or more substances selected from the group consisting of: styrene-acrylonitrile copolymers, (meth) acrylic acid polymers, polybutadiene and silicone resins.

[0156] This aspect can impart heat resistance and low-temperature impact resistance to the cured product of the resin composition.

[0157] In the resin composition according to the ninth aspect (which may be implemented in combination with any one of the first to eighth aspects), the average particle size of the core-shell type rubber is less than 1 μm.

[0158] This aspect makes it easier to fill the gaps between adjacent portions of the conductor lines when the insulating layer is formed from the resin composition on the surface of the printed wiring board having the conductor lines. This aspect is particularly effective for printed wiring boards on which fine-line conductor line patterns (so-called "fine patterns") have been formed at high density.

[0159] In the resin composition according to the tenth aspect (which may be implemented in combination with any one of the first to ninth aspects), the inorganic filler includes one or more compounds selected from the group consisting of silica, talc, boehmite, magnesium hydroxide and aluminum hydroxide.

[0160] This aspect is particularly effective in contributing to reducing the thermal expansion of the cured product of the resin composition to a sufficiently low level.

[0161] The prepreg (1) according to the eleventh aspect comprises: a base material (11); and a resin layer (10) made of a semi-cured product of the resin composition according to any one of the first to tenth aspects. The semi-cured product is impregnated into the base material (11).

[0162] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0163] The film (2) with resin according to the twelfth aspect comprises: a resin layer (20) made of a semi-cured product of the resin composition according to any one of the first to tenth aspects; and a support film (21) supporting the resin layer (20) thereon.

[0164] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0165] The metal foil sheet (3) with resin according to the thirteenth aspect comprises: a resin layer (30) made of a semi-cured product of the resin composition according to any one of the first to tenth aspects; and a metal foil sheet (31) combined with the resin layer (30).

[0166] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0167] The metal-clad laminate (4) according to the fourteenth aspect includes: an insulating layer (40) made of a cured product of the resin composition described in any one of the first to tenth aspects or a cured product of the prepreg (1) described in the eleventh aspect; and at least one metal layer (41) formed on one surface or both surfaces of the insulating layer (40).

[0168] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0169] The printed wiring board (5) according to the fifteenth aspect comprises: an insulating layer (50) made of a cured product of the resin composition according to any one of the first to tenth aspects or a cured product of the prepreg (1) according to the eleventh aspect; and at least one conductor line (51) formed on one surface or both surfaces of the insulating layer (50).

[0170] This aspect enables a substrate to be obtained having a low coefficient of thermal expansion, a high glass transition temperature (Tg) and excellent resistance to desmearing.

[0171] Example

[0172] Next, the present disclosure will be specifically described by way of illustrative embodiments. Note that the following are merely embodiments of the present disclosure and should not be construed as limiting.

[0173] (1) Resin composition

[0174] The following materials are provided as materials for resin compositions. Then, epoxy compounds, phenolic compounds, maleimide compounds, core-shell rubbers, inorganic fillers, and curing accelerators are mixed together to obtain any of the compositions shown in Tables 1-3 below. Those compositions are each diluted with a solvent (such as methyl ethyl ketone), and then stirred and mixed to obtain a uniform concentration. In this way, a resin composition is prepared.

[0175] (1.1) Epoxides

[0176] ● a biphenyl aralkyl type epoxy resin (product name "NC-3500", produced by Nippon Kayaku Co., Ltd., and having an epoxy equivalent of 209 g / eq),

[0177] ● a naphthalene type epoxy resin (product name "HP-9500", produced by DIC Corporation, and having an epoxy equivalent of 230 g / eq),

[0178] ● an epoxy resin containing a triphenylmethane skeleton (product name "EPPN-502H", produced by Nippon Kayaku Co., Ltd., and having an epoxy equivalent of 158-178 g / eq),

[0179] ● a naphthalene type epoxy resin (product name "HP-4710", produced by DIC Corporation, and having an epoxy equivalent of 170 g / eq), and

[0180] ● Biphenyl aralkyl type epoxy resin (product name "NC-3000-H", produced by Nippon Kayaku Co., Ltd., and having an epoxy equivalent of 280-300 g / eq).

[0181] (1.2) Phenolic compounds

[0182] ● Naphthyl phenolic resin phenolic resin (product name "HPC9500P-53M", produced by DIC Corporation, and having a hydroxyl equivalent of 153 g / eq),

[0183] ● a biphenyl aralkyl type phenol resin (product name "MEHC-7403H", produced by Meiwa Kasei Industries, Ltd., and having a hydroxyl equivalent of 132 g / eq), and

[0184] A phosphorus-containing phenol compound (product name "XZ92741.00", produced by the Dow Chemical Company Japan, and having a hydroxyl group equivalent of 550 g / eq).

[0185] (1.3) Maleimide compounds

[0186] ● Phenylmethanemaleimide (product name "BMI-2300", produced by Daiwa Chemical Industry Co., Ltd.), and

[0187] Biphenyl aralkyl type maleimide resin (product name "MIR-3000 70MT", produced by Nippon Kayaku Co., Ltd.).

[0188] (1.4) Core-shell rubber

[0189] ● Methyl methacrylate butadiene styrene core-shell rubber (product name "TMS-2670J", produced by the Dow Chemical Company Japan; core: methyl methacrylate / butadiene / styrene copolymer; shell: methyl methacrylate polymer; average particle size 0.151 μm),

[0190] ● Acrylic rubber (product name "AC3816N", produced by Aica Kogyo Co., Ltd.; core: cross-linked acrylic acid polymer; shell: methyl methacrylate polymer; average particle size: 0.3 µm), and

[0191] ● Silicone resin-acrylic composite rubber (product name "SRK200A", produced by Mitsubishi Chemical Corporation; core: silicone resin / acrylic polymer; shell: styrene acrylonitrile copolymer; average particle size: 0.15 μm).

[0192] (1.5) Inorganic fillers

[0193] ● Silicon dioxide (product name "SC-2050MTX", produced by Admatechs, and having an average particle size of 0.5 μm),

[0194] ● Silicon dioxide (product name "SC-2050MNU", produced by Admatechs, and having an average particle size of 0.5 μm),

[0195] ● Aluminum hydroxide (product name "ALH-F", produced by Kawai Lime Industry Co., Ltd., and having an average particle size of 5.2 μm), and

[0196] ● Magnesium hydroxide (product name "KISUMA 8SN", produced by Kyowa Chemical Industry Co., Ltd., and having an average particle size of 1.48 µm).

[0197] (1.6) Curing accelerator

[0198] 2-Ethyl-4-methylimidazole (product name "2E4MZ", produced by Shikoku Chemicals Corporation).

[0199] (2) Prepreg

[0200] A glass cloth sheet (#2118 type, WEA 2118T-107-S199, E glass, manufactured by Nitto Boseki Co., Ltd.) is provided. The glass cloth sheet is a textile sheet whose warp and weft yarns are woven substantially perpendicular to each other. This glass cloth sheet is impregnated with a resin composition so that the thickness of the cured product of the prepreg will be 100 μm. Next, the resin composition impregnated into the glass cloth sheet is heated and dried by a non-contact heating unit until the resin composition is semi-cured. The heating temperature is in the range of 120°C to 130°C. In this way, the solvent is removed from the resin composition, thereby manufacturing a prepreg comprising a glass cloth sheet and a semi-cured product of the resin composition impregnated into the glass cloth sheet. Relative to 100 parts by mass of the prepreg, the resin content (i.e., the content of the resin) of the prepreg is 41 parts by mass.

[0201] (3) Metal-clad laminate

[0202] Two prepregs each having the above structure are stacked on each other to obtain a stack of prepregs. Copper foil sheets (thickness of 12 μm) are laminated to each of the two surfaces of the stack thus obtained, thereby forming a stack of prepregs with copper foil sheets. Then, the stack of prepregs with copper foil sheets is molded under heating and pressure to make a double-sided metal laminate with a thickness of 0.2 mm. The molding process under heating and pressure is carried out under the conditions of 220°C, 2 MPa and 90 minutes.

[0203] (4) Experiment

[0204] (4.1) Coefficient of thermal expansion (CTE)

[0205] The copper foil sheet that has been bonded to both surfaces of the double-sided metal laminate is etched away to obtain an unclad board. Using this unclad board as a sample, the coefficient of thermal expansion (CTE) is measured perpendicular to the thickness direction in a temperature range of 50° C. to 260° C. The measurement is performed by a thermomechanical analysis (TMA) method that complies with the IPC TM650 2.4.41 standard.

[0206] (4.2) Glass transition temperature (Tg)

[0207] The copper foil sheets bonded to both surfaces of the double-sided metal-clad laminate were etched away to obtain an unclad board. The unclad board was cut in a slanted direction forming an inclination of 45 degrees with respect to the warp and weft of the glass cloth sheet, thereby obtaining a sample having a size of 50 mm×5 mm.

[0208] The tan δ of the sample was measured using a dynamic mechanical spectrometer ("DMS6100" by SII Nanotechnology Inc.) at a heating rate of 5°C / min (by dynamic mechanical analysis (DMA)). The peak temperature thereof was considered to be the glass transition temperature (Tg).

[0209] (4.3) Stain removal resistance

[0210] The desmear resistance was evaluated by the desmear etch rate calculated as the difference between the mass of the following untreated test piece to be subjected to the desmear process and the mass of the following treated test piece which had been subjected to the desmear process using permanganate.

[0211] Specifically, a copper foil sheet that had been bonded to a double-sided metal-clad laminate having a size of 5 cm × 5 cm was etched away to obtain a test piece. Then, the desmear etching rate (in mg / cm2) was calculated based on the difference between the mass of the untreated test piece to be subjected to the desmear process (initial mass) and the mass of the treated test piece that had been subjected to the desmear process under the following conditions:2 ).

[0212] After the test pieces were dried at 130° C. for 30 minutes and then air-cooled in a desiccator for two hours, the initial mass of the untreated test pieces was measured.

[0213] The mass of the processed test pieces was measured in the following manner.

[0214] (a) Swelling process

[0215] First, after measuring its initial mass, the untreated test piece was swollen in "Swelling Dip Securiganth P (500 ml / L)" produced by Atotech Japan and an aqueous sodium hydroxide solution (40 g / L) for 5 minutes.

[0216] (b) Stain removal process

[0217] Next, the test piece was subjected to a micro-etching process for 10 minutes using "Concentrate Compact CP (580 ml / L)" produced by Atotech Japan and an aqueous sodium hydroxide solution (40 g / L).

[0218] (c) Neutralization process

[0219] Next, the test piece was neutralized with "Reduction Solution Securiganth P500 (70 ml / L)" manufactured by Atotech Japan and sulfuric acid (98%, 50 ml / L) for 5 minutes.

[0220] (d) Drying process

[0221] Next, the test piece was dried at 130° C. for 30 minutes.

[0222] Then, the stain removal resistance was evaluated in each of the following single pass and double pass.

[0223] In 1 pass, after the test piece has been subjected to a series of processes (a) to (d) once, the test piece is air-cooled for 2 hours, and then the quality of the treated test piece is measured. In this way, the desmear etching rate of 1 pass is measured.

[0224] In 2 passes, after the test piece had undergone a series of processes (a) to (c) twice and had undergone process (d), the test piece was air-cooled for 2 hours and then the quality of the treated test piece was measured. In this way, the desmear etching rate of 2 passes was measured.

[0225] When the desmear etch rate is 0.3 mg / cm in one pass2 Below and in 2 passes 0.5 mg / cm 2 When the value was less than 0.05, the stain removal resistance was evaluated as excellent.

[0226] [Table 1]

[0227]

[0228] [Table 2]

[0229]

[0230] [Table 3]

[0231]

[0232] List of Reference Numerals

[0233] 1 Prepreg

[0234] 2 resin layer

[0235] 11 Base material

[0236] 2 Film with resin

[0237] 20 resin layers

[0238] 21 Support film

[0239] 3 Metal foil sheet with resin

[0240] 30 resin layers

[0241] 31 Metal foil sheet

[0242] 4 Metal-clad laminate

[0243] 40 insulation layer

[0244] 41 metal layers

[0245] 5. Printed Circuit Board

[0246] 50 insulation layer

[0247] 51 conductor line

Claims

1. A resin composition, comprising: an epoxy compound; Maleimide compound having N-phenylmaleimide structure; phenolic compound; core-shell rubber; and inorganic fillers, The content of the maleimide compound is within a range of 10 parts by mass to less than 40 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound, The phenolic compounds include phosphorus-containing phenolic compounds and phosphorus-free phenolic compounds. The phosphorus-containing phenolic compound has a structure represented by the following chemical formula (4): The phosphorus-free phenolic compound includes a biphenyl aralkyl type phenolic resin, The inorganic filler includes silicon dioxide and magnesium hydroxide: (4) Where * represents a chemical bond.

2. The resin composition according to claim 1, wherein The maleimide compound includes a maleimide compound further having a biphenyl structure.

3. The resin composition according to claim 2, wherein The maleimide compound includes a compound represented by the following chemical formula (1): (1) in, R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

4. The resin composition according to claim 1, wherein The maleimide compound includes a compound represented by the following chemical formula (2): (2) in, R represents a group which is the same as or different from each other and each of which is a hydrogen atom or an alkyl group; and n is an integer in the range of 0 to 4.

5. The resin composition according to claim 1, wherein The epoxy compound includes an epoxy compound having at least one of a naphthalene skeleton or a biphenyl skeleton.

6. The resin composition according to claim 1, wherein The phenolic compound includes a phenolic compound having at least one of a naphthalene skeleton and a biphenyl skeleton.

7. The resin composition according to claim 1, wherein The content of the phenolic compound is in the range of 10 parts by mass to 30 parts by mass relative to 100 parts by mass of the total amount of the epoxy compound, the maleimide compound and the phenolic compound.

8. The resin composition according to claim 1, wherein The core-shell rubber comprises a core and a shell covering the core. The core comprises one or more substances selected from the group consisting of a polymer of (meth)acrylic acid, a polymer of (meth)acrylate, a polymer of an olefin compound, polybutadiene, and a silicone resin, and The shell includes one or more substances selected from the group consisting of styrene-acrylonitrile copolymers, (meth)acrylic acid polymers, polybutadiene, and silicone resins.

9. The resin composition according to claim 1, wherein The core-shell rubber has an average particle size of less than 1 μm.

10. The resin composition according to claim 1, wherein The cured product of the resin composition has a glass transition temperature of 260° C. or higher.

11. A prepreg, comprising: Base material; and a resin layer made of a semi-cured product of the resin composition according to any one of claims 1 to 10, the semi-cured product being impregnated into the base material.

12. A film having a resin, comprising: A resin layer made of a semi-cured product of the resin composition according to any one of claims 1 to 10; and a support film supporting the resin layer thereon.

13. A metal foil sheet with resin, comprising: A resin layer made of a semi-cured product of the resin composition according to any one of claims 1 to 10; and a metal foil sheet combined with the resin layer.

14. A metal-clad laminate, comprising: An insulating layer made of a cured product of the resin composition according to any one of claims 1 to 10; and at least one metal layer formed on one surface or both surfaces of the insulating layer.

15. A printed circuit board, comprising: An insulating layer made of a cured product of the resin composition according to any one of claims 1 to 10; and at least one conductor line formed on one surface or both surfaces of the insulating layer.

16. A metal-clad laminate, comprising: An insulating layer made of a cured product of the prepreg according to claim 11; and at least one metal layer formed on one surface or both surfaces of the insulating layer.

17. A printed circuit board, comprising: An insulating layer made of a cured product of the prepreg according to claim 11; and at least one conductor line formed on one surface or both surfaces of the insulating layer.

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