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

Abstract

This resin composition contains a curable resin. In the present invention, according to dynamic viscoelasticity measurement, the minimum value (Min) of the ratio of the loss elastic modulus (E") to the storage elastic modulus (E'), which is loss tangent (tanδ = E" / E'), of a cured product of this resin composition is 0.04 or greater at 100℃ to 200℃ .

Description

[Technical Field]

[0001] The present disclosure generally relates to a resin composition, a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a printed wiring board. More specifically, the present disclosure relates to a resin composition containing a curable resin, and a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a printed wiring board using the resin composition. [Background technology]

[0002] In order to improve the mounting reliability of semiconductor packages (PKGs), research has been conducted to reduce warpage in substrate materials. One of the results of this research is a method for increasing the rigidity and decreasing the CTE (coefficient of thermal expansion) of substrate materials. This method is based on the idea of ​​eliminating the mismatch between the thermal expansion coefficients of the substrate and the semiconductor chips mounted on it by bringing the thermal expansion coefficient of the substrate closer to that of the semiconductor chips mounted on the substrate.

[0003] However, with the remarkable progress in semiconductor technology in recent years, the structure of semiconductor packages may change significantly in the future. In such cases, the method based on the above concept may not be applicable to semiconductor packages with changed structures, and therefore lacks versatility.

[0004] Therefore, methods different from the above-mentioned concept are also being considered. For example, Patent Document 1 discloses a prepreg that employs a method different from conventional methods. This prepreg is formed from a resin composition and a woven fabric substrate. This resin composition contains (A) an epoxy resin or the like having a naphthalene skeleton, (B) a polymer having a specific structure, and (C) an inorganic filler.

[0005] The prepreg described in Patent Document 1 is a highly versatile substrate material, but there is room for further improvement in terms of warpage reduction and heat resistance. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-002305 Summary of the Invention

[0007] An object of the present disclosure is to provide a resin composition, a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a printed wiring board that can be used to produce a substrate with reduced warping and improved heat resistance.

[0008] A resin composition according to one embodiment of the present disclosure contains a curable resin. A cured product of the resin composition has a minimum loss tangent (tanδ=E″ / E′), which is the ratio of the loss modulus (E″) to the storage modulus (E′), of 0.04 or more at a temperature of 100°C or higher and 200°C or lower, as determined by dynamic viscoelasticity measurement.

[0009] A prepreg according to one aspect of the present disclosure includes a substrate and a resin layer impregnated into the substrate and including the resin composition or a semi-cured product of the resin composition.

[0010] A resin-coated film according to one embodiment of the present disclosure includes a resin layer containing the resin composition or a semi-cured product of the resin composition, and a support film that supports the resin layer.

[0011] A resin-coated metal foil according to one embodiment of the present disclosure includes a resin layer containing the resin composition or a semi-cured product of the resin composition, and a metal foil adhered to the resin layer.

[0012] A metal-clad laminate according to one embodiment of the present disclosure comprises an insulating layer including a cured product of the resin composition or a cured product of the prepreg, and a metal layer adhered to the insulating layer.

[0013] A printed wiring board according to one aspect of the present disclosure includes an insulating layer including a cured product of the resin composition or a cured product of the prepreg, and conductor wiring formed on the insulating layer. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a tan δ temperature curve showing the temperature dependency of loss tangent (tan δ) for the examples and comparative examples. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a prepreg according to one embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic plan view showing a base material used in the prepreg. [Figure 4] 4A and 4B are schematic cross-sectional views showing a resin-coated film (without a protective film) according to an embodiment of the present disclosure, respectively. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a resin-coated metal foil according to one embodiment of the present disclosure. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a metal-clad laminate according to one embodiment of the present disclosure. [Figure 7] 7A and 7B are schematic cross-sectional views showing a printed wiring board (without interlayer connections) according to an embodiment of the present disclosure. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a semiconductor package according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1. Overview The resin composition according to this embodiment contains a curable resin and can be used as a substrate material, which is not particularly limited, but includes, for example, a prepreg 1, a resin-coated film 2, a resin-coated metal foil 3, a metal-clad laminate 4, and a printed wiring board 5 (see FIGS. 2 to 7B).

[0016] While conducting research into substrate warpage, the inventors discovered that adjusting the loss tangent (tan δ) of the substrate material to a higher value than conventional methods makes it easier for the substrate to absorb stress. In other words, they discovered that increasing tan δ can enhance stress absorption and reduce substrate warpage. They also discovered that this improves heat resistance.

[0017] Specifically, the minimum value (Min) of the loss tangent (tan δ) of the cured product of the resin composition according to this embodiment at temperatures between 100°C and 200°C is 0.04 or more. This will be explained with reference to the drawings. FIG. 1 is a tan δ temperature curve showing the temperature dependence of the loss tangent (tan δ). In FIG. 1, Examples 1 and 3 satisfy the conditions of the resin composition according to this embodiment. This makes it easier for the substrate to absorb stress. Therefore, according to Examples 1 and 3, it is possible to manufacture a substrate with reduced warpage and improved heat resistance (see Table 1).

[0018] In contrast, Comparative Examples 1, 2, and 5 do not satisfy the conditions of the resin composition according to this embodiment. As a result, the substrate has difficulty absorbing stress. Therefore, in Comparative Examples 1, 2, and 5, the substrate is likely to warp significantly.

[0019] On the other hand, Comparative Example 4 also does not satisfy the conditions of the resin composition according to this embodiment. In Comparative Example 4, the warpage of the substrate is not so great, but the heat resistance is poor (see Table 2). Details of each example and comparative example will be described later (see the Examples section).

[0020] 2.Details The resin composition according to this embodiment will be described in detail below. Furthermore, the prepreg 1, resin-coated film 2, resin-coated metal foil 3, metal-clad laminate 4, printed wiring board 5, and semiconductor package 100 according to this embodiment will be described in detail with reference to the drawings. For convenience of explanation, arrows indicating the mutually orthogonal X, Y, and Z directions are shown in some of the drawings, but these arrows do not actually represent any physical objects.

[0021] (1) Resin composition <Viscoelastic properties> The resin composition according to this embodiment exhibits the following viscoelastic properties. That is, one of the features of the resin composition according to this embodiment is that it has a higher loss tangent (tanδ=E" / E') than existing materials. Specifically, the minimum value (Min) of the loss tangent of the cured product of the resin composition at temperatures of 100°C to 200°C is 0.04 or more (see the tanδ temperature curves of Examples 1 and 3 in Figure 1).

[0022] Here, the loss tangent (tanδ) is the ratio (E" / E') of the loss modulus (E") to the storage modulus (E'). The storage modulus (E') is the internal energy of an object (cured product) caused by strain. On the other hand, the loss modulus (E") is the thermal energy of an object caused by strain. As mentioned above, if the minimum value (Min) of the loss tangent at temperatures between 100°C and 200°C is 0.04 or higher, the stress generated inside the cured product due to intermolecular friction within the cured product can be easily released as thermal energy. The storage modulus (E'), loss modulus (E"), and loss tangent (tanδ = E" / E') can be obtained by dynamic mechanical analysis (DMA).

[0023] One of the features of the resin composition according to this embodiment is that the tan δ temperature curve has a baseline within the range of 100°C to 200°C and does not exhibit a peak (see Examples 1 and 3 in FIG. 1). In other words, the cured product of the resin composition according to this embodiment does not have a glass transition temperature (Tg) within the range of 100°C to 200°C. In FIG. 1, the range of 100°C to 200°C is the range sandwiched between two vertical axes, Y(100) and Y(200). Y(100) is the vertical axis indicating the position of 100°C. Y(200) is the vertical axis indicating the position of 200°C. Comparative Example 5 exhibits a peak within the range of 100°C to 200°C (see FIG. 1).

[0024] Here, the baseline refers to the portion of the curve in the temperature range where the loss tangent of the sample is almost unchanged. In other words, the baseline refers to the line that is almost flat in the range of 100°C to 200°C on the tan δ temperature curve. The peak refers to the portion of the tan δ temperature curve where the curve leaves the baseline and returns to the baseline.

[0025] Another feature of the resin composition according to this embodiment is that the baseline of the tan δ-temperature curve is higher than the baseline of the tan δ-temperature curve of existing materials. In Figure 1, the baselines of the tan δ-temperature curves of Examples 1 and 3 are higher than X(0.05) on the horizontal axis, while the baselines of the tan δ-temperature curves of Comparative Examples 1, 2, 4, and 5 are lower than X(0.05) on the horizontal axis. X(0.05) is the horizontal axis indicating the point where the loss tangent (tan δ) is 0.05.

[0026] The resin composition according to this embodiment exhibits the above-described viscoelastic properties, which allows the substrate to more easily absorb stress. That is, when deformation (strain) is applied to the substrate, the viscous properties of the substrate convert mechanical energy into thermal energy, thereby absorbing the stress. Therefore, the resin composition according to this embodiment makes it possible to manufacture a substrate with reduced warpage.

[0027] Preferably, the resin composition according to this embodiment exhibits the following viscoelastic properties: As shown in the tan δ-temperature curves of Examples 1 and 3 in Figure 1, Max(B) / Max(A) is preferably less than 1. This can further reduce warpage of the substrate.

[0028] Here, Max(B) is the maximum value of the loss tangent of the cured product of the resin composition at 100°C or higher and 200°C or lower. Max(A) is the maximum value of the loss tangent of the cured product of the resin composition at 30°C or higher and lower than 100°C and at temperatures higher than 200°C and lower than 300°C. In FIG. 1, the range of 30°C or higher and lower than 100°C is the range sandwiched between two vertical axes, Y(30) and Y(100). Y(30) is the vertical axis indicating the 30°C position. On the other hand, the range of higher than 200°C and lower than 300°C is the range sandwiched between two vertical axes, Y(200) and Y(300). Y(300) is the vertical axis indicating the 300°C position.

[0029] The maximum value of the loss tangent (Max(A)) in Examples 1 and 3 in Fig. 1 does not lie within the range of 30°C or higher and lower than 100°C, but lies within the range of more than 200°C and 300°C or lower. Although not shown in Fig. 1, the maximum value of the loss tangent (Max(A)) may lie within the range of 30°C or higher and lower than 100°C, but may not lie within the range of more than 200°C and 300°C or lower. Furthermore, the maximum value of the loss tangent (Max(A)) within the range of 30°C or higher and lower than 100°C may be the same as the maximum value of the loss tangent (Max(A)) within the range of more than 200°C and 300°C or lower.

[0030] The present inventors have furthered their research and development and identified components of a resin composition that can exhibit the above-mentioned viscoelastic properties. That is, the resin composition according to this embodiment contains a curable resin. Preferably, the resin composition further contains a styrene copolymer (C). More preferably, the resin composition further contains an inorganic filler (D). The resin composition may further contain other components (E).

[0031] Preferably, the curable resin contains a long-chain-containing compound (A1). More preferably, the curable resin further contains a non-long-chain-containing compound (A2). Even more preferably, the curable resin further contains a resin component (B). The resin component (B) is a resin component excluding the long-chain-containing compound (A1), the non-long-chain-containing compound (A2), and the styrene copolymer (C). The components of the resin composition will be described below.

[0032] <Curing resin> <Long-chain-containing compound (A1)> The long-chain-containing compound is a compound having a long-chain hydrocarbon group and a first functional group.

[0033] The long-chain hydrocarbon group includes an alkyl group having 6 or more carbon atoms and / or an alkylene group having 6 or more carbon atoms. That is, the long-chain hydrocarbon group has at least one of an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms. The upper limit of the number of carbon atoms in the alkyl group is not particularly limited, but is, for example, 100. The upper limit of the number of carbon atoms in the alkylene group is not particularly limited, but is, for example, 100. Thus, since the long-chain-containing compound (A1) has a long-chain hydrocarbon group of 6 or more carbon atoms, it is easy to increase the loss tangent (tan δ) of the substrate. Moreover, it is easy to improve the heat resistance of the substrate.

[0034] On the other hand, the first functional group includes at least one selected from the group consisting of an epoxy group, a maleimide group, an imide group, and a hydroxyl group.

[0035] Preferably, the long-chain-containing compound (A1) includes at least one selected from the group consisting of a maleimide compound (A3) represented by the following formula (a3), a maleimide compound (A4) represented by the following formula (a4), and a maleimide compound (A5) represented by the following formula (a5): (A3)(A4) or (A5) When the resin composition contains the compound, the loss tangent (tan δ) of the substrate can be increased.

[0036] [ka]

[0037] (In formula (a3), n represents an integer of 1 to 10.)

[0038] [ka]

[0039] (In formula (a4), n represents an integer of 1 to 10.)

[0040] [ka]

[0041] Preferably, the long-chain-containing compound (A1) is a maleimide compound, and the maleimide group equivalent weight is 400 g / eq or more. This further reduces warpage of the substrate. The upper limit of the maleimide group equivalent weight is preferably 3000 g / eq or less, more preferably 2000 g / eq or less. The maleimide group equivalent weight is a value obtained by dividing the molecular weight of the maleimide compound by the number of maleimide groups contained in the maleimide compound. In other words, the maleimide group equivalent weight is the molecular weight per maleimide group.

[0042] Preferably, the content of the long-chain compound (A1) is 30 parts by mass or more and 75 parts by mass or less per 100 parts by mass of the curable resin and the styrene copolymer (C) in total, which can further reduce warpage of the substrate.

[0043] ≪Long chain-free compound (A2)≫ The long-chain-free compound (A2) is a compound that does not have a long-chain hydrocarbon group but has a second functional group.

[0044] The long-chain hydrocarbon group is as described above. Thus, the long-chain-free compound (A2) does not have a long-chain hydrocarbon group of C6 or more.

[0045] On the other hand, the second functional group contains at least one selected from the group consisting of an epoxy group, a maleimide group, an imide group, and a hydroxyl group. That is, the second functional group of the long-chain-free compound (A2) and the first functional group of the long-chain-containing compound (A1) share the same type of functional group. The second functional group may be the same as or different from the first functional group.

[0046] If the second functional group of the long-chain-free compound (A2) is different from the first functional group of the long-chain-containing compound (A1), the two compounds are less compatible with each other and more likely to undergo phase separation, which makes it easier to maintain the loss tangent of the cured resin composition within a predetermined temperature range (e.g., 100°C or higher and 200°C or lower).

[0047] Preferably, the long-chain-free compound (A2) is a maleimide compound, and the maleimide group equivalent weight is less than 400 g / eq. This allows the glass transition temperature (Tg) of the substrate to be increased. By increasing the Tg of the substrate, cracks are less likely to occur in the substrate, improving the reliability of interlayer connections. That is, even when stress such as a thermal shock test is applied to a substrate such as a multilayer printed wiring board, cracks are less likely to occur in the substrate, thereby suppressing increases in the resistance values ​​of via holes and through holes and improving the reliability of interlayer connections. In particular, in recent years, with the increasing density and miniaturization of wiring, via holes and through holes are also becoming smaller in diameter, so increasing the Tg of the substrate is effective. The lower limit of the maleimide group equivalent weight is preferably 150 g / eq or more, more preferably 200 g / eq or more.

[0048] The long-chain-free compound (A2) having a maleimide group equivalent weight of less than 400 g / eq is not particularly limited, but includes, for example, the maleimide compound (A7) represented by the following formula (a7): The maleimide compound (A7) is 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide.

[0049] [ka]

[0050] When the curable resin contains both the long-chain-containing compound (A1) and the non-long-chain-containing compound (A2), the content of the non-long-chain-containing compound (A2) is preferably 5 parts by mass or more and 50 parts by mass or less, more preferably 10 parts by mass or more and 40 parts by mass or less, relative to 100 parts by mass of the total of the long-chain-containing compound (A1) and the non-long-chain-containing compound (A2).

[0051] <Resin component (B)> Preferably, the curable resin further contains a resin component (B), which refers to a resin component excluding the long-chain-containing compound (A1), the long-chain-free compound (A2), and the styrene-based copolymer (C).

[0052] The inclusion of at least the long-chain compound (A1) and the resin component (B) in the resin composition can increase the loss tangent of the cured product of the resin composition. For example, if a curable resin contains both the long-chain compound (A1) and the non-long-chain compound (A2), and both the long-chain compound (A1) and the non-long-chain compound (A2) are maleimide compounds, the long-chain compound (A1) and the non-long-chain compound (A2) will phase-separate because the former contains a long-chain hydrocarbon group and the latter does not, but they can still react. While this approach still allows the loss tangent of the cured product to be adjusted higher than conventional methods, suppressing the reaction while maintaining the phase separation can further increase the loss tangent of the cured product. Because the resin component (B) phase-separates from at least the long-chain compound (A1) and is less likely to react, it is preferable to include the long-chain compound (A1) and the resin component (B) in the resin composition, as described above. In this case, the resin composition may further contain a long-chain-free compound (A2).

[0053] Preferably, the resin component (B) has a glass transition temperature (Tg) of 200°C or higher. More preferably, the resin component (B) is incompatible or poorly compatible with at least one of the long-chain-containing compound (A1), the long-chain-free compound (A2), and the styrene copolymer (C). When the resin composition is prone to phase separation, the tan δ-temperature curve may have a baseline in the range of 100°C to 200°C. Conversely, when the resin compositions are prone to compatibility, the tan δ-temperature curve may have a sharp peak in the range of 100°C to 200°C.

[0054] Preferably, the resin component (B) contains at least one selected from the group consisting of an epoxy compound, a phenol compound, a polyphenylene ether compound, a modified polyphenylene ether compound having a reactive unsaturated group, a benzoxazine compound, a radically polymerizable compound having a polymerizable unsaturated group, a cyanate ester compound, and an amine compound. This can impart properties specific to each resin component (B) to the resin composition. For example, it can improve desmear resistance and electrical properties. In particular, when the long-chain-containing compound (A1) contains a maleimide compound, the resin component (B) preferably contains an epoxy compound.

[0055] An epoxy compound is a compound having at least one (preferably two or more) epoxy group in its molecule. Specific examples of epoxy compounds include, but are not limited to, dicyclopentadiene-type epoxy resins, naphthalene-type epoxy resins, biphenyl-type epoxy resins, and mesogenic skeleton epoxy resins. A mesogenic skeleton epoxy resin is an epoxy resin having at least one mesogenic group in its molecule. A mesogenic group is a rigid structure and is the smallest unit structure capable of forming a liquid crystal structure. Specific examples of mesogenic groups include, but are not limited to, a biphenyl structure and a phenylbenzoate structure.

[0056] Preferably, the epoxy equivalent of the epoxy compound is 200 g / eq or more and 350 g / eq or less. This allows the glass transition temperature (Tg) of the substrate to be increased. As described above, increasing the Tg of the substrate makes it less likely for cracks to occur in the substrate, and can improve the reliability of interlayer connections.

[0057] The phenol compound is a compound obtained by polymerizing a phenol and formaldehyde with an acidic or basic catalyst. The phenol compound is not particularly limited, but examples thereof include phenol novolak.

[0058] When the curable resin further contains a resin component (B), the content of the resin component (B) is preferably 5 parts by mass or more and 55 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the total of the curable resin and the styrene-based copolymer (C).

[0059] <Styrene-based copolymer (C)> Preferably, the resin composition further contains a styrene copolymer (C), which can further reduce warpage of the substrate.

[0060] The styrene copolymer (C) has at least one structure derived from a styrene compound and / or a styrene derivative. The styrene compound and / or the styrene derivative is not particularly limited, but examples thereof include styrene, α-methylstyrene, p-methylstyrene, compounds in which a portion of the hydrogen atoms in the aromatic rings thereof are substituted with alkyl groups, and polymers thereof. The styrene copolymer (C) may further have a structure derived from a conjugated diene compound.

[0061] The styrene copolymer (C) may be either non-hydrogenated or hydrogenated. Non-hydrogenated refers to a substance that has not been hydrogenated. Hydrogenated refers to a substance that has been hydrogenated. Preferably, the weight-average molecular weight of the styrene copolymer (C) is 10,000 or more and 150,000 or less. Inclusion of such a styrene copolymer (C) in the resin composition can further reduce warpage of the substrate. When the weight-average molecular weight of the styrene copolymer (C) is 10,000 or more, a decrease in desmear resistance can be suppressed. Desmear resistance refers to the ability to adequately remove smears, which are resin stains remaining after drilling a substrate. On the other hand, when the weight-average molecular weight of the styrene copolymer (C) is 150,000 or less, a decrease in flame resistance can be suppressed.

[0062] Preferably, the styrene copolymer (C) comprises at least one selected from the group consisting of methylstyrene (ethylene / butylene) methylstyrene copolymer, methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, styrene-isoprene copolymer, styrene-isoprene styrene copolymer, styrene (ethylene / butylene) styrene copolymer, styrene (ethylene-ethylene / propylene) styrene copolymer, and hydrogenated products thereof. By including such a styrene copolymer (C) in the resin composition, warpage of the substrate can be further reduced.

[0063] When the resin composition further contains a styrene copolymer (C), the content of the styrene copolymer (C) is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 10 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the total of the curable resin and the styrene copolymer (C), thereby further reducing warpage of the substrate.

[0064] <Inorganic filler (D)> Preferably, the resin composition further contains an inorganic filler (D), which can reduce the thermal expansion coefficient (linear expansion coefficient) of the substrate.

[0065] Preferably, the inorganic filler (D) contains at least one selected from the group consisting of metal oxides, metal hydroxides, talc, aluminum borate, barium sulfate, calcium carbonate, and zinc molybdate. Examples of metal oxides include, but are not limited to, silica, alumina, titanium oxide, and mica. Examples of metal hydroxides include, but are not limited to, aluminum hydroxide and magnesium hydroxide.

[0066] Preferably, the inorganic filler (D) is surface-treated with a surface treatment agent. This improves wettability with the long-chain-containing compound (A1), the long-chain-free compound (A2), the resin component (B), and the styrene copolymer (C), thereby improving the dispersibility of the inorganic filler (D). Examples of surface treatment agents include, but are not limited to, silane coupling agents, titanate coupling agents, fatty acids, and surfactants. Preferably, the silane coupling agent has at least one functional group selected from the group consisting of vinyl groups, epoxy groups, styryl groups, methacrylic groups, acrylic groups, amino groups, isocyanurate groups, ureido groups, mercapto groups, isocyanate groups, and acid anhydride groups.

[0067] The inorganic filler (D) is preferably spherical in shape, which can improve the fluidity of the resin composition during molding.

[0068] The inorganic filler (D) has an average particle size of preferably 0.01 μm to 50 μm, more preferably 0.05 μm to 20 μm, where the average particle size means the particle size at 50% cumulative value in the particle size distribution determined by a laser diffraction / scattering method.

[0069] When the resin composition further contains an inorganic filler (D), the content of the inorganic filler (D) is preferably 20 parts by mass or more and 200 parts by mass or less, and preferably 50 parts by mass or more and 150 parts by mass or less, per 100 parts by mass of the curable resin and the styrene copolymer (C) in total.

[0070] <Others (E)> The resin composition may further contain other components (E). The other components (E) are not particularly limited, but examples thereof include catalytic curing agents, crosslinking agents, reaction initiators, resin modifiers, antifoaming agents, heat stabilizers, antistatic agents, UV absorbers, dyes, pigments, lubricants, dispersants such as wetting and dispersing agents, and leveling agents. Examples of catalytic curing agents include imidazole compounds such as 2-ethyl-4-methylimidazole. Examples of reaction initiators include organic peroxides such as α,α'-di(t-butylperoxy)diisopropylbenzene. The content of the other components (E) is not particularly limited as long as it does not impair the effects of this embodiment.

[0071] <Form> The form of the resin composition is not particularly limited. The resin composition may be liquid or solid. The liquid form includes a varnish. A varnish can be prepared by stirring and mixing the resin composition with a solvent. The solvent is not particularly limited, but examples thereof include toluene, methyl ethyl ketone, cyclohexanone, and propylene glycol monomethyl ether acetate.

[0072] (2) Prepreg FIG. 2 shows a prepreg 1 according to this embodiment. The prepreg 1 is generally in the form of a sheet or film. That is, the prepreg 1 extends in the X and Y directions. The prepreg 1 is used as a material for a metal-clad laminate 4, a material for a printed wiring board 5, and for multi-layering (build-up method) printed wiring boards 5. The prepreg 1 hardens into a cured product when heated or irradiated with light (ultraviolet light). The cured product of the prepreg 1 can form the insulating layer 40 of the metal-clad laminate 4 and the insulating layer 50 of the printed wiring board 5 (see FIGS. 6 to 7B).

[0073] The prepreg 1 includes a substrate 11 and a resin layer 10 containing a resin composition or a semi-cured product of the resin composition impregnated into the substrate 11. One prepreg 1 includes at least one substrate 11.

[0074] The substrate 11 is not particularly limited, but examples thereof include woven fabric and nonwoven fabric.

[0075] The woven fabric is not particularly limited, but examples thereof include glass cloth, aramid cloth, and polyester cloth.

[0076] The nonwoven fabric is not particularly limited, but examples thereof include glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper.

[0077] The glass fibers constituting the glass cloth and glass nonwoven fabric are not particularly limited, but examples thereof include Q glass, NE glass, E glass, S glass, T glass, L glass, and L2 glass.

[0078] The thickness of the substrate 11 is preferably 5 μm or more and 300 μm or less, and more preferably 10 μm or more and 200 μm or less.

[0079] The surface of the substrate 11 may be surface-treated with a silane coupling agent. The silane coupling agent is not particularly limited, but examples thereof include silane coupling agents having at least one functional group selected from the group consisting of a vinyl group, an epoxy group, a styryl group, a methacryl group, an acrylic group, an amino group, an isocyanurate group, a ureido group, a mercapto group, an isocyanate group, and an acid anhydride group.

[0080] An example of the substrate 11 is shown in Figure 3. The substrate 11 is a woven fabric made of warp threads 111 and weft threads 112. The direction of the warp threads 111 (X direction) and the direction of the weft threads 112 (Y direction) are perpendicular to each other. The substrate 11 extends in the X direction and the Y direction. A bias direction BD is a direction that intersects with the direction of the warp threads 111 (X direction). The angle formed between the bias direction BD and the direction of the warp threads 111 (X direction) is θ (for example, 45°).

[0081] The resin layer 10 is divided into a case where it contains a resin composition (first case) and a case where it contains a semi-cured product of the resin composition (second case).

[0082] In the first case, the resin layer 10 is formed as follows. That is, the base material 11 is impregnated with a varnish of a resin composition, and then the solvent is volatilized to form the resin layer 10. The resin layer 10 is formed from an unreacted resin composition (dried product). Here, the unreacted state includes a state in which no reaction has occurred and a state in which almost no reaction has occurred. The resin layer 10 changes from an unreacted state to a cured state by being heated.

[0083] On the other hand, in the second case, the resin composition is in a semi-cured state. Here, the semi-cured state refers to a state in an intermediate stage (B stage) of the curing reaction. The intermediate stage is a stage between the varnish state stage (A stage) and the cured state stage (C stage). In the second case, the resin layer 10 is formed as follows. That is, after impregnating the base material 11 with a varnish of the resin composition, the base material 11 is heated to volatilize the solvent and the curing reaction of the resin composition is allowed to proceed to the intermediate stage, thereby forming the resin layer 10. This resin layer 10 is formed from a resin composition in a semi-cured state (semi-cured product).

[0084] As described above, the progress of the curing reaction of the resin layer 10 may differ depending on the resin composition used.

[0085] The thickness of the prepreg 1 (thickness in the Z direction) is not particularly limited, but is, for example, 10 μm or more and 120 μm or less, which can realize a thinner board.

[0086] As described above, the resin layer 10 of the prepreg 1 according to this embodiment is formed from the above-mentioned resin composition, and therefore it is possible to manufacture a substrate with reduced warpage.

[0087] (3) Resin-coated film 4A shows a resin-coated film 2 according to this embodiment. The resin-coated film 2 is in the form of a film or sheet as a whole. The resin-coated film 2 comprises a resin layer 20 containing a resin composition or a semi-cured product of a resin composition, and a support film 21 that supports the resin layer 20. The resin-coated film 2 is used for multi-layering printed wiring boards 5 (build-up method), etc.

[0088] When heated or irradiated with light (ultraviolet light), the resin layer 20 hardens to form the insulating layer 40 of the metal-clad laminate 4 and the insulating layer 50 of the printed wiring board 5 (see FIGS. 6 to 7B). The resin layer 20 is similar to the resin layer 10 of the prepreg 1, except that it is not impregnated into the base material 11.

[0089] The thickness of the resin layer 20 is not particularly limited, but is, for example, 10 μm or more and 120 μm or less, which can make the substrate thinner.

[0090] The support film 21 supports the resin layer 20. This makes the resin layer 20 easier to handle. The support film 21 can be peeled off from the resin layer 20 as needed. Preferably, the resin layer 20 is cured to form the insulating layer 40, and then the support film 21 is peeled off from the insulating layer 40. The same applies when forming the insulating layer 50 from the resin layer 20.

[0091] The support film 21 is, for example, an electrically insulating film, but is not particularly limited thereto. Specific examples of the support film 21 include polyethylene terephthalate (PET) film, polyimide film, polyester film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, aramid film, polycarbonate film, and polyarylate film. The support film 21 is not limited to these films.

[0092] In FIG. 4A , one surface of the resin layer 20 is covered with a support film 21. However, as shown in FIG. 4B , one surface of the resin layer 20 may be covered with a support film 21, and the other surface of the resin layer 20 may be covered with a protective film 22. Like the support film 21, the protective film 22 can also be peeled off from the resin layer 20 as needed. By covering both surfaces of the resin layer 20 in this way, the resin layer 20 becomes even easier to handle. Furthermore, adhesion of foreign matter to the resin layer 20 can be suppressed.

[0093] The protective film 22 is, for example, an electrically insulating film, but is not limited thereto. Specific examples of the protective film 22 include a polyethylene terephthalate (PET) film, a polyolefin film, a polyester film, and a polymethylpentene film. The protective film 22 is not limited to these films.

[0094] As described above, the resin layer 20 of the resin-coated film 2 according to this embodiment is formed from the above-mentioned resin composition, so that it is possible to manufacture a substrate with reduced warpage.

[0095] (4) Resin-coated metal foil Fig. 5 shows a resin-coated metal foil 3 according to this embodiment. The resin-coated metal foil 3 is in the form of a film or sheet as a whole. The resin-coated metal foil 3 comprises a resin layer 30 containing a resin composition or a semi-cured product of the resin composition, and a metal foil 31 adhered to the resin layer 30. The resin-coated metal foil 3 is used for multi-layering printed wiring boards 5 (build-up method), etc.

[0096] When heated or irradiated with light (ultraviolet light), the resin layer 30 hardens to form the insulating layer 40 of the metal-clad laminate 4 and the insulating layer 50 of the printed wiring board (see FIGS. 6 to 7B). The resin layer 30 is similar to the resin layer 10 of the prepreg 1, except that it is not impregnated into the base material 11.

[0097] The thickness of the resin layer 30 is not particularly limited, but is, for example, 10 μm or more and 120 μm or less, which can make the substrate thinner.

[0098] The metal foil 31 is adhered to the resin layer 30. Specific examples of the metal foil 31 include, but are not limited to, copper foil, aluminum foil, and nickel foil. The metal foil 31 can be etched away to form conductive wiring 51 in a subtractive method or the like (see FIG. 7A, etc.).

[0099] The thickness of the metal foil 31 is not particularly limited, but is preferably, for example, 0.2 μm or more and 35 μm or less.

[0100] When the metal foil 31 is an ultra-thin metal foil, it is preferable that the metal foil 31 be part of an ultra-thin metal foil with a carrier, from the viewpoint of improving handleability. The ultra-thin metal foil with a carrier comprises the metal foil 31 (ultra-thin metal foil), a release layer, and a carrier. In this case, the thickness of the metal foil 31 is, for example, 10 μm or less. The release layer is a layer that temporarily bonds the metal foil 31 and the carrier. If necessary, the metal foil 31 is peeled off from the release layer or the carrier. The carrier is a support that supports the metal foil 31. Specific examples of the carrier include copper foil and aluminum foil. The thickness of the carrier is thicker than that of the metal foil 31.

[0101] As described above, the resin layer 30 of the resin-coated metal foil 3 according to this embodiment is formed from the above-mentioned resin composition, so that it is possible to manufacture a substrate with reduced warpage.

[0102] (5)Metal-clad laminate 6 shows a metal-clad laminate 4 according to this embodiment. The metal-clad laminate 4 includes an insulating layer 40 and a metal layer 41 bonded to the insulating layer 40. The insulating layer 40 includes a cured product of a resin composition or a cured product of a prepreg 1. The metal-clad laminate 4 is used as a material for a printed wiring board 5, etc.

[0103] In FIG. 6, one insulating layer 40 has one substrate 42, but one insulating layer 40 may have two or more substrates 42.

[0104] The thickness of the insulating layer 40 is not particularly limited, but is, for example, 10 μm or more and 120 μm or less, which can make the substrate thinner.

[0105] In Fig. 6, the metal layer 41 is bonded to both sides of the insulating layer 40, but it may be bonded to only one side. A metal-clad laminate 4 in which the metal layer 41 is bonded to both sides of the insulating layer 40 is a double-sided metal-clad laminate. A metal-clad laminate 4 in which the metal layer 41 is bonded to only one side of the insulating layer 40 is a single-sided metal-clad laminate.

[0106] The metal layer 41 is not particularly limited, but examples thereof include metal foil etc. The metal foil is not particularly limited, but examples thereof include copper foil, aluminum foil, and nickel foil etc.

[0107] The thickness of the metal layer 41 is not particularly limited, but is, for example, 0.2 μm or more and 35 μm or less. When the metal layer 41 is an ultra-thin metal foil, from the viewpoint of improving handling, the metal layer 41 is preferably a part of an ultra-thin metal foil with a carrier. The ultra-thin metal foil with a carrier is as described above.

[0108] As described above, since the insulating layer 40 of the metal-clad laminate 4 according to this embodiment is formed from the above-mentioned resin composition, it is possible to manufacture a substrate with reduced warpage.

[0109] (6) Printed wiring board 7A and 7B show a printed wiring board 5 according to this embodiment. The printed wiring board 5 includes an insulating layer 50 and conductive wiring 51 formed on the insulating layer 50. The insulating layer 50 includes a cured product of a resin composition or a cured product of a prepreg 1.

[0110] The printed wiring board 5 shown in FIG. 7A has one insulating layer 50. In FIG. 7A, one insulating layer 50 has one substrate 52, but one insulating layer 50 may have two or more substrates 52. On the other hand, the printed wiring board 5 shown in FIG. 7B has multiple (specifically, three) insulating layers 50. That is, the three insulating layers 50 are a first insulating layer 510, a second insulating layer 520, and a third insulating layer 530. These insulating layers 50 are stacked and bonded in order in the thickness direction. In FIG. 7B, each of the first insulating layer 510, the second insulating layer 520, and the third insulating layer 530 may have no substrate 52 or one or more substrates 52. In this way, the insulating layer 50 is similar to the insulating layer 40 of the metal-clad laminate 4 described above.

[0111] 7A, the conductor wiring 51 is formed on both sides of the insulating layer 50. The conductor wiring 51 may be formed on only one side of the insulating layer 50.

[0112] On the other hand, in the printed wiring board 5 shown in FIG. 7B , the conductor wiring 51 includes an inner layer circuit 511 and an outer layer circuit 512. The inner layer circuit 511 is located between two insulating layers 50. That is, the inner layer circuit 511 is located between the first insulating layer 510 and the second insulating layer 520, and between the second insulating layer 520 and the third insulating layer 530. The outer layer circuit 512 is located outside the insulating layers 50. That is, the outer layer circuit 512 is formed on the surfaces of the first insulating layer 510 and the third insulating layer 530. The printed wiring board 5 shown in FIG. 7B further includes a via hole 8 and a blind via hole 9. The via hole 8 and the blind via hole 9 electrically connect the inner layer circuit 511 and the outer layer circuit 512. That is, the via hole 8 and the blind via hole 9 provide interlayer connection between the inner layer circuit 511 and the outer layer circuit 512.

[0113] The method for forming the conductor wiring 51 is not particularly limited, but examples thereof include a subtractive method and a semi-additive method (SAP: Semi-Additive Process).

[0114] As described above, insulating layer 50 of printed wiring board 5 according to this embodiment is formed from the above-mentioned resin composition, making it possible to manufacture a board with reduced warpage.

[0115] (7) Semiconductor Package FIG. 8 shows a semiconductor package 100 according to this embodiment. The semiconductor package 100 includes a printed wiring board 5 and a semiconductor chip 7 mounted on the printed wiring board 5. In this case, the printed wiring board 5 is also called a package substrate, a module substrate, or an interposer. The printed wiring board 5 has at least one insulating layer 50. The insulating layer 50 has at least one base material 52. The insulating layer 50 does not necessarily have to have the base material 52.

[0116] The insulating layer 50 has conductive wiring 51. The conductive wiring 51 includes a pad 513. The pad 513 is formed on the surface of the insulating layer 50.

[0117] There are no particular limitations on the semiconductor chip 7. The semiconductor chip 7 has bumps 70. The bumps 70 are bonded to the pads 513. This electrically connects the semiconductor chip 7 and the printed wiring board 5.

[0118] An underfill resin layer 500 is formed between the semiconductor chip 7 and the printed wiring board 5. The underfill resin layer 500 is formed by filling the gap between the semiconductor chip 7 and the printed wiring board 5 with an underfill liquid sealing material and curing it.

[0119] As described above, the semiconductor package 100 according to this embodiment includes the above-described printed wiring board 5, and therefore, it is possible to reduce warpage. [Example]

[0120] The present disclosure will be specifically described below with reference to examples, but the present disclosure is not limited to the examples.

[0121] (1) Resin composition The raw materials for the resin composition are as follows:

[0122] <Curing resin> <Long-chain-containing compound (A1)> Maleimide compound (A5) represented by formula (a5), Designer Molecules Inc. (DMI), trade name "BMI-689", maleimide group equivalent weight 345 g / eq Maleimide compound (A4) represented by formula (a4), Designer Molecules Inc. (DMI), product name "BMI-1500", maleimide group equivalent weight 750 g / eq Maleimide compound (A3) represented by formula (a3), Designer Molecules Inc. (DMI), product name "BMI-3000", maleimide group equivalent weight 1500 g / eq ≪Long chain-free compound (A2)≫ Maleimide compound (A7) represented by formula (a7), manufactured by Daiwa Chemical Industry Co., Ltd., under the trade name "BMI-5100," with an equivalent weight of maleimide groups of 221 g / eq <Resin component (B)> [Epoxy Compound] Dicyclopentadiene epoxy resin, DIC Corporation, product name "HP-7200" (epoxy equivalent weight 254-264g / eq) Naphthalene-type epoxy resin, DIC Corporation, product name "HP-9500" (epoxy equivalent weight 230g / eq) [Phenol compounds] Phenol novolac, DIC Corporation, product name "TD-2090" (hydroxyl equivalent: 105g / eq).

[0123] <Styrene-based copolymer (C)> Hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated styrenic thermoplastic elastomer (SEBS), Kuraray Co., Ltd., product name "Septon (registered trademark) V9827" (weight average molecular weight 92,000).

[0124] <Acrylic resin> Acrylic resin, Shin-Nakamura Chemical Co., Ltd., product name "KV-8161".

[0125] <Inorganic filler (D)> Fused silica, Admatechs Co., Ltd., product name "SC2050-MTX", average particle size 0.5 μm.

[0126] <Others (E)> 2-Ethyl-4-methylimidazole, Shikoku Chemicals Corporation, "2E4MZ".

[0127] The long-chain-containing compound (A1), the long-chain-free compound (A2), the resin component (B), the styrene copolymer (C), the inorganic filler (D), and the other components (E) were blended in the amounts shown in Tables 1 and 2, and the blend was stirred and mixed with an appropriate solvent to homogenize, thereby preparing a varnish of the resin composition.

[0128] (2) Prepreg The varnish was impregnated into glass cloth (Nitto Boseki Co., Ltd., #2116 type, WEA116E, E glass, thickness 0.1 mm), and then heated and dried at 100 to 160°C for about 2 to 8 minutes to produce a prepreg.

[0129] (3)Metal-clad laminate Two sheets of the above prepreg were stacked, and 12 μm thick copper foil was placed on both sides. The laminate was heated and pressed at 220°C for 2 hours at a pressure of 3 MPa to produce a double-sided copper-clad laminate (double-sided metal-clad laminate) with a thickness of approximately 0.2 mm. This was used as an evaluation board for the following tests.

[0130] (4) Examination (4.1) Loss tangent (tanδ) First, the copper foil on both sides of the evaluation substrate was removed by etching to obtain an unclad board. Next, this unclad board was cut into 5 mm wide strips in a direction tilted 45° from the warp direction of the substrate (bias direction) to prepare 25 mm long specimens. Dynamic mechanical analysis (DMA) was performed on these specimens using a dynamic viscoelasticity measuring device (SII Nano Technology Inc., model "DMS6100") under the following conditions: a chucking distance of 10 mm, a heating rate of 5°C / min, a frequency of 10 Hz, and tension mode. From this measurement, the loss tangent (tanδ) was calculated as the minimum value (Min) between 100 and 200°C.

[0131] Next, Max(B) / Max(A) was calculated from the tan δ-temperature curve. In particular, the tan δ-temperature curves of Examples 1 and 3 and Comparative Examples 1, 2, 4, and 5 are shown in FIG.

[0132] (4.2) Package warpage First, a semiconductor package (PKG) was manufactured to measure the amount of package warpage (see Figure 8). Specifically, unnecessary copper foil on one side of an evaluation board (12 mm x 12 mm) was removed by etching to form conductive wiring (pads), and the copper foil on the other side of the evaluation board was completely removed by etching. A semiconductor chip measuring 10 mm x 10 mm x 0.1 mm thick was also prepared. The semiconductor chip had bumps.

[0133] Then, the bumps of the semiconductor chip were bonded to the pads of the evaluation substrate, and the gap between the evaluation substrate and the semiconductor chip was filled with a liquid underfill sealant (Panasonic Corporation, product name "CV5300AM") and allowed to harden. In this way, a simple semiconductor package was manufactured for measuring the amount of package warpage.

[0134] Next, the warpage of the above semiconductor package was measured based on the shadow moire measurement theory using a warpage measurement device (AKROMETRIX, model "THERMOIRE PS200"). Specifically, the amount of package warpage was measured as follows. The above semiconductor package was heated in two stages. In the first stage, it was heated from 30°C (starting temperature) to 260°C, and then cooled to 30°C (finishing temperature). In the second stage, it was similarly heated from 30°C (starting temperature) to 260°C, and then cooled to 30°C (finishing temperature). The amount of warpage at 30°C in the second stage was taken as the amount of package warpage. Note that the amounts of warpage at the starting and ending temperatures in the second stage were almost the same.

[0135] (4.3) Glass transition temperature (Tg) First, the copper foil on both sides of the evaluation substrate was removed by etching to obtain an unclad plate. Next, the glass transition temperature (Tg) of the unclad plate was measured using a Seiko Instruments Inc. viscoelasticity spectrometer "DMS100." Dynamic mechanical analysis (DMA) was performed using a bending module at a frequency of 10 Hz. The glass transition temperature (Tg) was determined as the temperature at which the loss tangent (tanδ) reached a maximum when the temperature was increased from room temperature to 320°C at a heating rate of 5°C / min. Glass transition temperatures (Tg) exceeding 300°C are indicated as ">300" in Tables 1 and 2.

[0136] (4.4) Heat resistance A test piece measuring 5 cm x 5 cm was cut out from the evaluation substrate. This test piece was then placed in a dryer at 290°C for 1 hour. After that, the test piece was removed from the dryer and visually observed, and the heat resistance was evaluated according to the following criteria.

[0137] "A": No swelling "B": Swelling present.

[0138] [Table 1]

[0139] [Table 2] [Explanation of symbols]

[0140] 1 Prepreg 10 Resin layer 11 Base material 2 Resin-coated film 20 Resin layer 21 Support film 3 Resin-coated metal foil 30 resin layer 31 Metal foil 4 Metal-clad laminate 40 insulating layer 41 Metal layer 5. Printed wiring board 50 insulating layer 51 Conductor wiring

Claims

1. A resin composition comprising a curable resin and a catalytic curing agent, The curable resin is a maleimide compound represented by the following formula (a3), a maleimide compound represented by the following formula (a4), or a maleimide compound represented by the following formula (a5); a dicyclopentadiene-type epoxy resin or a naphthalene-type epoxy resin, the minimum value of loss tangent (tanδ=E″ / E′), which is the ratio of loss modulus (E″) to storage modulus (E′) at 100° C. or higher and 200° C. or lower, obtained by dynamic viscoelasticity measurement of the cured product of the resin composition, is 0.04 or higher; Resin composition. 【Chemistry 1】 (In formula (a3), n represents an integer of 1 to 10.) 【Chemistry 2】 (In formula (a4), n represents an integer of 1 to 10.) 【Transformation 3】

2. A resin composition comprising a curable resin, an inorganic filler, and a catalytic curing agent, The curable resin is a maleimide compound represented by the following formula (a3); a naphthalene-type epoxy resin, the minimum value of loss tangent (tanδ=E″ / E′), which is the ratio of loss modulus (E″) to storage modulus (E′) at 100° C. or higher and 200° C. or lower, obtained by dynamic viscoelasticity measurement of the cured product of the resin composition, is 0.04 or higher; Resin composition. 【Chemistry 4】 (In formula (a3), n represents an integer of 1 to 10.)

3. A resin composition comprising a curable resin, an inorganic filler, and a catalytic curing agent, The curable resin is a maleimide compound represented by the following formula (a3) ​​and a maleimide compound represented by the following formula (a7); a naphthalene-type epoxy resin, the minimum value of loss tangent (tanδ=E″ / E′), which is the ratio of loss modulus (E″) to storage modulus (E′) at 100° C. or higher and 200° C. or lower, obtained by dynamic viscoelasticity measurement of the cured product of the resin composition, is 0.04 or higher; Resin composition. 【Transformation 5】 (In formula (a3), n represents an integer of 1 to 10.) 【Transformation 6】

4. A resin composition comprising a curable resin, a styrene-based copolymer, an inorganic filler, and a catalytic curing agent, The curable resin is a maleimide compound represented by the following formula (a3); a naphthalene-type epoxy resin, the minimum value of loss tangent (tanδ=E″ / E′), which is the ratio of loss modulus (E″) to storage modulus (E′) at 100° C. or higher and 200° C. or lower, obtained by dynamic viscoelasticity measurement of the cured product of the resin composition, is 0.04 or higher; Resin composition. 【Transformation 7】 (In formula (a3), n represents an integer of 1 to 10.)

5. When the maximum value of the loss tangent of the cured product obtained by dynamic viscoelasticity measurement at 100°C or higher and 200°C or lower is defined as Max(B), and the maximum value of the loss tangent of the cured product obtained by dynamic viscoelasticity measurement at 30°C or higher and lower than 100°C and higher than 200°C and lower than 300°C is defined as Max(A), Max(B) / Max(A) is less than 1. The resin composition according to any one of claims 1 to 4.

6. A substrate and a resin layer impregnated in the substrate and containing the resin composition according to any one of claims 1 to 5 or a semi-cured product of the resin composition. Prepreg.

7. A resin layer comprising the resin composition according to any one of claims 1 to 5 or a semi-cured product of the resin composition, and a support film supporting the resin layer. Resin-coated film.

8. A resin layer comprising the resin composition according to any one of claims 1 to 5 or a semi-cured product of the resin composition, and a metal foil adhered to the resin layer. Metal foil with resin.

9. An insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 5 or a cured product of the prepreg according to claim 6, and a metal layer adhered to the insulating layer. Metal-clad laminate.

10. An insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 5 or a cured product of the prepreg according to claim 6, and conductor wiring formed on the insulating layer. Printed wiring board.

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