Resin composition, resin film material, printed wiring board, and method for manufacturing printed wiring board

Abstract

The present disclosure provides a resin composition, with which, when a resin layer of a resin film material is produced, the resin layer is more likely to have flexibility, and when a laminate including a resin layer is hot-pressed, a component in the resin layer does not easily flow out. The resin composition contains a resin component (A) and a phosphorus-containing flame retardant (B). The resin component (A) contains an epoxy resin (a1) having a viscosity at 25 °C of at most 50,000 mPa·s. The ratio of the epoxy resin (a1) to the resin component (A) is at least 20 mass%. The phosphorus-containing flame retardant (B) contains a phosphorus-containing flame retardant (B1) that does not melt and thermally decompose below 150 °C.

Description

[Technical Field]

[0001] The present disclosure relates to a resin composition, a resin film material, a printed wiring board, and a method for manufacturing a printed wiring board, and more particularly to a thermosetting resin composition, a resin film material having a resin layer made from the resin composition, a printed wiring board made from the resin composition, and a method for manufacturing a printed wiring board using the resin film material. [Background technology]

[0002] When producing a printed wiring board, for example, a core material having a conductor and a resin layer containing an uncured or semi-cured resin composition are stacked to produce a laminate, and the laminate is then heat-pressed. For example, Patent Document 1 discloses that a multilayer printed wiring board is produced by forming a laminate by disposing a heat-meltable and thermosetting resin film between a substrate having via holes and a prepreg containing an inorganic filler. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-37362 Summary of the Invention

[0004] An object of the present disclosure is to provide a resin composition that makes the resin layer flexible when producing a resin film material having a resin layer, and that prevents components in the resin layer from leaking out when a laminate including the resin layer is hot-pressed; a resin film material having a resin layer produced from the resin composition; a printed wiring board produced from the resin composition; and a method for producing a printed wiring board using the resin film material.

[0005] A resin composition according to one embodiment of the present disclosure contains a resin component (A) and a phosphorus-containing flame retardant (B). The resin component (A) contains an epoxy resin (a1) having a viscosity of 50,000 mPa·s or less at 25°C. The proportion of the epoxy resin (a1) relative to the resin component (A) is 20 mass% or more. The phosphorus-containing flame retardant (B) contains a phosphorus-containing flame retardant (B1) that does not melt or thermally decompose at temperatures below 150°C.

[0006] A resin film material according to one embodiment of the present disclosure includes a carrier film and a resin layer that is overlaid on the carrier film and contains an uncured or semi-cured product of the resin composition.

[0007] A printed wiring board according to an embodiment of the present disclosure includes a conductor wiring and an insulating layer overlying the conductor wiring, the insulating layer including a cured product of the resin composition.

[0008] A method for manufacturing a printed wiring board according to one aspect of the present disclosure includes hot pressing a laminate including a core material having conductor wiring and the resin layer of the resin film material. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic cross-sectional view of a resin film material according to one embodiment of the present disclosure. [Figure 2] 2A and 2B are schematic cross-sectional views illustrating a state in which a film material and a core material are stacked according to an embodiment of the present disclosure, respectively, and a resin layer and a core material are stacked according to an embodiment of the present disclosure. [Figure 3] 3A and 3B are schematic cross-sectional views of a laminate including a resin layer according to an embodiment of the present disclosure, and a printed wiring board according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] In order to improve the handleability of a resin film material used for producing a printed wiring board, etc., it is preferable that the resin layer in the resin film material is flexible and that powder falling off from the resin layer is unlikely to occur.

[0011] The inventors adjusted the composition of the resin layer to increase its flexibility, but found that the resin layer's fluidity was excessively high when heated. Therefore, when the resin layer was overlaid on conductor wiring on a substrate or the like and hot-pressed, the components in the resin layer were likely to flow out of the laminate containing the resin layer. In particular, when the resin layer is overlaid on thick conductor wiring, the resin layer must be sufficiently fluidized to fill the gaps in the conductor wiring, making the components of the resin layer particularly susceptible to flowing out. This makes it easy for a resin shortage to occur in the insulating layer made from the resin layer.

[0012] Therefore, the inventors conducted research and development to obtain a resin composition that makes the resin layer more flexible when producing a resin film material having a resin layer, and that makes it difficult for the components in the resin layer to leak out when a laminate including the resin layer is hot-pressed, and has thus completed the present disclosure.

[0013] An embodiment of the present disclosure will be described.

[0014] The resin composition according to this embodiment (hereinafter also referred to as composition (X)) contains a resin component (A) and a phosphorus-containing flame retardant (B). The resin component (A) contains an epoxy resin (a1) having a viscosity of 50,000 mPa·s or less at 25°C. The proportion of the epoxy resin (a1) relative to the resin component (A) is 20 mass% or more. The phosphorus-containing flame retardant (B) contains a phosphorus-containing flame retardant (B1) (hereinafter referred to as heat-resistant flame retardant (B1)) that does not melt or thermally decompose at temperatures below 150°C.

[0015] According to this embodiment, the flame retardancy of the cured product of the composition (X) can be achieved by the phosphorus-containing flame retardant (B), so the cured product can be flame retarded without using a halogen compound. Therefore, the composition (X) and the cured product can be made into a halogen-free material. The definition of a halogen-free material is based on the standard (JPCA-ES01) of the JPCA (Japan Electronics Packaging and Circuits Association).

[0016] Furthermore, when the resin component (A) contains the epoxy resin (a1) and the ratio of the epoxy resin (a1) to the resin component (A) is 20% by mass or more, the resin layer 1 produced from the composition (X) tends to be flexible and powder is less likely to fall off from the resin layer 1. Therefore, the resin film material 10 including the resin layer 1 tends to have good handleability.

[0017] Furthermore, even if the composition (X) contains a low-viscosity epoxy resin (a1), the composition (X) contains a heat-resistant flame retardant (B1) that does not melt at temperatures below 150°C. Therefore, when a laminate 3 (see FIG. 3A) including the resin layer 1 is heat-pressed, the components in the resin layer 1 are unlikely to flow out.

[0018] Therefore, according to this embodiment, when resin layer 1 is produced from composition (X), resin layer 1 is likely to have flexibility, and components in resin layer 1 are less likely to flow out when laminate 3 including resin layer 1 is heat-pressed.

[0019] The composition of composition (X) will be explained in more detail below.

[0020] As described above, the composition (X) contains the resin component (A) and the phosphorus-containing flame retardant (B).

[0021] The resin component (A) is a thermosetting component. The resin component (A) contains a thermosetting resin. The component contained in the thermosetting resin may be a monomer or a prepolymer. The thermosetting resin contains an epoxy resin (a). The thermosetting resin may further contain at least one resin selected from the group consisting of a polyimide resin, a phenolic resin, a bismaleimide triazine resin, and a thermosetting polyphenylene ether resin.

[0022] The epoxy resin (a) contains at least one component selected from the group consisting of, for example, bisphenol A type epoxy resins, bisphenol F type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol F novolac type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, dicyclopentadiene type epoxy resins, and polyfunctional type epoxy resins.

[0023] The components that the thermosetting resin and the epoxy resin (a) may contain are not limited to those mentioned above.

[0024] The epoxy resin (a) contains an epoxy resin (a1) having a viscosity of 50,000 mPa·s or less at 25°C. That is, the resin component (A) contains the epoxy resin (a1). The viscosity is measured using a Brookfield viscometer with a standard spindle No. 3 at a rotation speed of 60 rpm. The viscosity of the epoxy resin (a) at 25°C is preferably 25,000 mPa·s or less, and even more preferably 10,000 mPa·s or less. In this case, the handleability of the resin film material 10 having the resin layer 1 is particularly improved. Furthermore, this viscosity is preferably 1,000 mPa·s or more. In this case, when the composition (X) contains an inorganic filler, the inorganic filler is easily dispersible, and the thickness of the resin layer 1 can be easily controlled when the resin layer 1 is prepared from the composition (X). This viscosity is more preferably 3,000 mPa·s or more, and even more preferably 5,000 mPa·s or more.

[0025] The epoxy resin (a1) may contain an appropriate liquid epoxy resin that satisfies the above viscosity conditions. For example, the epoxy resin (a1) may contain at least one component selected from the group consisting of liquid bisphenol A epoxy resin, liquid bisphenol F epoxy resin, liquid bisphenol B epoxy resin, and liquid bisphenol E epoxy resin, which satisfy the above viscosity conditions. When the epoxy resin (a1) contains a liquid epoxy resin, the flexibility of the resin layer 1 produced from the composition (X) is easily and effectively increased, and powder falling from the resin layer 1 is particularly unlikely to occur. However, the components that the epoxy resin (a1) may contain are not limited to those mentioned above.

[0026] The ratio of the epoxy resin (a1) to the resin component (A) is 20% by mass or more. Therefore, the epoxy resin (a1) effectively increases the flexibility of the resin layer 1 and is particularly unlikely to cause powder shedding from the resin layer 1. The ratio of this epoxy resin (a1) is preferably 50% by mass or less, and more preferably 40% by mass or less. The ratio of this epoxy resin (a1) is more preferably 25% by mass or more, and even more preferably 30% by mass or more. The epoxy resin (a) may contain only the epoxy resin (a1). The epoxy resin (a) may contain an epoxy resin other than the epoxy resin (a1). In this case, the ratio of the epoxy resin (a1) to the total epoxy resin (a) is, for example, 50% by mass or less.

[0027] In addition to the epoxy resin (a1), the epoxy resin (a) may further contain an epoxy resin (a2) that is solid at 25°C. That is, the resin component (A) may further contain the epoxy resin (a2). In this case, the composition (X) can be easily formed into a film by coating, etc., which facilitates the preparation of the resin layer 1 from the composition (X). The epoxy resin (a2) contains at least one component selected from the group consisting of polyfunctional epoxy resins, such as epoxy resins having a naphthalene skeleton and novolac-type epoxy resins. However, the components that the epoxy resin (a2) may contain are not limited to these. The proportion of the epoxy resin (a2) relative to the total epoxy resin (a) is preferably 40% by mass or more. In this case, the epoxy resin (a2) particularly tends to enhance the heat resistance of the cured product. The proportion of the epoxy resin (a2) is preferably 80% by mass or less. In this case, the flexibility of the cured product is easily enhanced, and powder shedding from the resin layer 1 is effectively prevented. The proportion of the epoxy resin (a2) is more preferably 50% by mass or more, and even more preferably 60% by mass or more.

[0028] As described above, composition (X) contains a phosphorus-containing flame retardant (B), and the phosphorus-containing flame retardant (B) contains a heat-resistant flame retardant (B1) that does not melt or thermally decompose below 150° C. "Does not melt or thermally decompose below 150° C." means that when the heat-resistant flame retardant (B1) has a melting point, the melting point is 150° C. or higher, and when the heat-resistant flame retardant (B1) does not have a melting point (i.e., when heated in a solid state, it does not melt but thermally decomposes), the thermal decomposition temperature is 150° C. or higher.

[0029] The heat-resistant flame retardant (B1) contains at least one component selected from the group consisting of metal phosphinates EXOLIT OP935 (thermal decomposition temperature 300°C or higher), EXOLIT OP930, EXOLIT OP1230, EXOLIT OP1240, EXOLIT OP1312, and EXOLIT OP1400, all of which are manufactured by Clariant Chemicals. However, the components that the heat-resistant flame retardant (B1) may contain are not limited to those listed above.

[0030] The ratio of the heat-resistant flame retardant (B1) to the resin component (A) is preferably 3% by mass or more and 10% by mass or less. When this ratio is 3% by mass or more, the phosphorus-containing flame retardant (B) can particularly prevent components in the resin layer 1 from flowing out. Furthermore, when this ratio is 10% by mass or less, the resin layer 1 can easily fill gaps in the conductor wiring 41, particularly when the resin layer 1 is molded while being superimposed on the conductor wiring 41 and flowed. This ratio is more preferably 4% by mass or more and 6% by mass or less, and even more preferably 5% by mass or more and 6% by mass or less.

[0031] The ratio of the heat-resistant flame retardant (B1) to the phosphorus-containing flame retardant (B) is preferably 30% by mass or more. In this case, the heat-resistant flame retardant (B1) can particularly prevent the components in the resin layer 1 from leaking out. This ratio is more preferably 50% by mass or more, and even more preferably 60% by mass or more. The phosphorus-containing flame retardant (B) may contain only the heat-resistant flame retardant (B1).

[0032] The phosphorus-containing flame retardant (B) may further contain a component other than the heat-resistant flame retardant (B1), i.e., a phosphorus-containing flame retardant (B2) having a melting point of less than 150°C (hereinafter referred to as non-heat-resistant flame retardant (B2)). The non-heat-resistant flame retardant (B2) may contain at least one component selected from the group consisting of, for example, PX-200 (melting point 90°C), an aromatic condensed phosphate ester manufactured by Daihachi Chemical Industry Co., Ltd., Rabitol FP-100 (melting point 110°C), a phosphazene compound manufactured by Fushimi Pharmaceutical Co., Ltd., and CR733S, an aromatic condensed phosphate ester manufactured by Daihachi Chemical Industry Co., Ltd. However, the components that the non-heat-resistant flame retardant (B2) may contain are not limited to those listed above.

[0033] The resin component (A) may further contain at least one of a curing agent (b) and a curing accelerator (c), which enhances the curability of the composition (X) and further suppresses the outflow of components in the resin layer 1.

[0034] The curing agent (b) contains at least one component selected from the group consisting of, for example, amine-based curing agents, difunctional or higher phenol-based curing agents, acid anhydride-based curing agents, dicyandiamide, and low-molecular-weight polyphenylene ether compounds. The components contained in the curing agent (b) are not limited to those listed above, as long as they can react with the epoxy resin (a) to cure the composition (X). The amount of the curing agent (b) is preferably 0.3 to 1.5 equivalents relative to 1 equivalent of the epoxy resin (a), more preferably 0.4 to 1.2 equivalents, and even more preferably 0.45 to 1.1 equivalents.

[0035] The curing accelerator (c) contains at least one component selected from the group consisting of imidazole compounds, tertiary amine compounds, organic phosphine compounds, and metal soaps. The components contained in the curing accelerator (c) are not limited to those listed above, as long as they accelerate the curing reaction of the resin component (A). The amount of the curing accelerator (c) relative to the epoxy resin (a) is preferably 0.02% by mass or more and 2.0% by mass or less, more preferably 0.05% by mass or more and 1.0% by mass or less, and even more preferably 0.07% by mass or more and 0.7% by mass or less.

[0036] Composition (X) may further contain an inorganic filler. The inorganic filler can adjust the linear expansion coefficient of the cured product of composition (X) and can also improve the heat resistance and flame resistance of composition (X). The inorganic filler contains at least one material selected from the group consisting of, for example, silica, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, talc, clay, mica, and molybdenum compounds.

[0037] The proportion of the inorganic filler in composition (X) is preferably 60% by mass or more and 90% by mass or less. A proportion of 60% by mass or more can particularly enhance the heat resistance and flame resistance of a cured product of composition (X). Furthermore, a proportion of 90% by mass or less can easily provide good moldability for composition (X). A proportion of 75% by mass or more and 85% by mass or less is more preferred.

[0038] Composition (X) may contain a solvent for viscosity adjustment, etc. The solvent may contain, for example, at least one of an appropriate organic solvent and water. The organic solvent may contain, for example, at least one component selected from the group consisting of benzene, toluene, N,N-dimethylformamide (DMF), acetone, methyl ethyl ketone, methanol, ethanol, cellosolves, etc.

[0039] Composition (X) may further contain additives other than the above components. The additives may contain at least one component selected from the group consisting of, for example, coupling agents, antifoaming agents, heat stabilizers, antistatic agents, UV absorbers, dyes, pigments, lubricants, and dispersants. However, the components that the additives may contain are not limited to those listed above.

[0040] 1, a resin film material 10 according to this embodiment includes a carrier film 7 and a resin layer 1 that is overlaid on the carrier film and contains an uncured or semi-cured product of composition (X). The resin layer 1 can be used as a material for producing a printed wiring board 5. That is, the resin layer 1 can be used to produce a printed wiring board 5 that includes an insulating layer 6 that contains a cured product of the resin layer 1 (i.e., a cured product of composition (X)).

[0041] The carrier film 7 is a flexible resin film such as a polyethylene terephthalate film. The surface of the carrier film 7 that overlaps the resin layer 1 is preferably treated to enhance releasability. An example of such a treatment is silicone coating. The thickness of the carrier film 7 is, for example, 10 μm or more and 150 μm or less.

[0042] To manufacture the resin film material 10, for example, the composition (X) is formed into a sheet on a carrier film 7 by a coating method or the like, and then dried or semi-cured by heating. This produces a resin layer 1 made of an uncured or semi-cured product of the composition (X), and a resin film material 10 comprising the carrier film 7 and the resin layer 1 is obtained. MaterialThe heating temperature is, for example, 100° C. or higher and 160° C. or lower, and the heating time is, for example, 5 minutes or higher and 10 minutes or lower.

[0043] The thickness of the resin layer 1 is preferably 50 μm or more and 400 μm or less. In this case, particularly when the resin layer 1 is molded while being superimposed on the conductor wiring 41 and flowed, the resin layer 1 is likely to fill the gaps between the conductor wiring 41. The thickness of the resin layer 1 is more preferably 55 μm or more and 300 μm or less, and even more preferably 60 μm or more and 250 μm or less.

[0044] Furthermore, the total thickness of the resin film material 10, which is the combination of the carrier film 7 and the resin layer 1, is, for example, 60 μm or more and 550 μm or less. If this thickness is 60 μm or more, the carrier film 7 particularly easily holds the resin layer 1, and the resin layer 1 is less likely to tear when the resin film material 10 is handled. If this thickness is 550 μm or less, the resin layer 1 is particularly easily peeled from the carrier film 7, and cracks in the resin layer 1 are less likely to occur when the resin film material 10 is stored in a rolled form. This thickness is more preferably 65 μm or more, and even more preferably 70 μm or more. Furthermore, this thickness is more preferably 450 μm or less, and even more preferably 400 μm or less.

[0045] The melt viscosity of the resin layer 1 at 150°C is preferably 400 Pa·s or higher. In this case, components in the resin layer 1 are particularly unlikely to flow out of the laminate 3, particularly when the laminate 3 including the resin layer 1 is hot-pressed. This melt viscosity is more preferably 450 Pa·s or higher, and even more preferably 500 Pa·s or higher. It is also preferable that the melt viscosity is 10,000 Pa·s or lower. In this case, when the laminate 3 including the resin layer 1 is hot-pressed, if the resin layer 1 overlaps the conductor wiring 41, the resin layer 1 easily deforms to conform to the conductor wiring 41, thereby preventing unfilled portions from occurring in the insulating layer 6 formed from the resin layer 1. This melt viscosity is more preferably 8,000 Pa·s or lower, and even more preferably 6,000 Pa·s or lower. The melt viscosity of the resin layer 1 can be controlled, for example, by appropriately adjusting the type and content of each of the components contained in the composition (X), such as the epoxy resin (a1) and the heat-resistant flame retardant (B1). The method for measuring the melt viscosity will be described later in the Examples section.

[0046] A printed wiring board 5 can be manufactured using the resin film material 10 according to this embodiment. The printed wiring board 5 includes, for example, conductor wiring 41 and an insulating layer 6 overlapping the conductor wiring 41, and the insulating layer 6 includes a cured product of the composition (X). The printed wiring board 5 is manufactured, for example, by hot pressing a laminate 3 including a core material 4 having the conductor wiring 41 and a resin layer 1. A specific example of a method for manufacturing the printed wiring board 5 is described below.

[0047] A resin film material 10, a prepreg 2, and a core material 4 are prepared.

[0048] The details of the resin film material 10 have already been explained.

[0049] The prepreg 2 includes, for example, a substrate and an uncured or semi-cured thermosetting resin composition (hereinafter also referred to as composition (Y)) impregnated into the substrate. The prepreg 2 is produced, for example, by impregnating the substrate with composition (Y) and then heating the composition (Y) to dry or semi-cure it.

[0050] The substrate is, for example, a woven fabric or a nonwoven fabric. The substrate is made of, for example, glass fiber, inorganic fiber other than glass fiber, or organic fiber. The organic fiber includes, for example, at least one material selected from the group consisting of aramid fiber, polyparaphenylenebenzobisoxazole (PBO) fiber, polybenzimidazole (PBI) fiber, polytetrafluoroethylene (PTFE) fiber, polyparaphenylenebenzobisthiazole (PBZT) fiber, and wholly aromatic polyester fiber.

[0051] Composition (Y) contains a thermosetting resin, and optionally contains a component selected from the group consisting of a curing agent, a curing accelerator, a rubber component, an inorganic filler, a flame retardant, an organic solvent, and the like.

[0052] The thermosetting resin contains at least one component selected from the group consisting of, for example, epoxy resins, polyimide resins, phenolic resins, and bismaleimide triazine resins. The epoxy resin may contain at least one component selected from the group consisting of, for example, oxazolidone epoxy resins, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, biphenyl epoxy resins, alicyclic epoxy resins, diglycidyl ether compounds of polyfunctional phenols, diglycidyl ether compounds of polyfunctional alcohols, phenol novolac epoxy resins which are glycidyl ethers of polycondensates of phenols and formaldehyde, cresol novolac epoxy resins, and bisphenol A novolac epoxy resins.

[0053] The curing agent may contain at least one component selected from the group consisting of, for example, diamine-based curing agents, difunctional or higher phenol-based curing agents, acid anhydride-based curing agents, dicyandiamide, and low-molecular-weight polyphenylene ether compounds.

[0054] The curing accelerator may contain, for example, at least one component selected from the group consisting of imidazole compounds, tertiary amine compounds, organic phosphine compounds, metal soaps, and the like.

[0055] The rubber component contains, for example, elastomer particles having a core-shell structure.

[0056] The inorganic filler contains at least one material selected from the group consisting of, for example, silica, molybdenum compounds, aluminum hydroxide, magnesium hydroxide, aluminum silicate, magnesium silicate, talc, clay, mica, and the like.

[0057] The flame retardant preferably contains a non-halogen flame retardant, such as a phosphorus-containing compound or a nitrogen-containing compound.

[0058] The organic solvent may contain at least one component selected from the group consisting of, for example, benzene, toluene, N,N-dimethylformamide (DMF), acetone, methyl ethyl ketone, methanol, ethanol, cellosolves, and the like.

[0059] The core material 4 includes, for example, an insulating layer 42 and conductor wiring 41 overlapping the insulating layer 42. The insulating layer 42 is made of, for example, an electrically insulating resin. The conductor wiring 41 is made of a metal such as copper. There is no particular limit to the thickness of the conductor wiring 41. In this embodiment, as described above, the resin layer 1 easily fills the gaps between the conductor wiring 41, so good filling properties can be obtained even if the conductor wiring 41 is thick. This makes the printed wiring board 5 according to this embodiment suitable for applications such as industrial equipment and automotive circuit boards that require the passage of relatively large currents. The thickness of the conductor wiring 41 is, for example, 200 μm or more. To achieve good filling properties, the thickness of the conductor wiring 41 is preferably 1000 μm or less. The thickness of the conductor wiring 41 is more preferably 200 μm or more and 800 μm or less, and even more preferably 200 μm or more and 600 μm or less.

[0060] When manufacturing a printed wiring board 5, for example, as shown in FIG. 2A, a resin film material 10 is overlaid on a core material 4 so that the resin layer and conductor wiring 41 face each other. Next, as shown in FIG. 2B, the carrier film 7 is removed from the resin layer 1 while the resin layer 1 remains overlaid on the core material 4. One or more prepregs 2 are then overlaid on the resin layer 1. That is, the core material 4, the resin layer 1, and one or more prepregs 2 are laminated in this order. Note that a metal foil such as copper foil may also be overlaid on the prepreg 2. This results in a laminate 3 including the prepreg 2, the resin layer 1, and the core material 4, as shown in FIG. 3A.

[0061] This laminate 3 is hot-pressed. The hot-pressing conditions are appropriately set depending on the composition, size, etc. of the resin layer 1 and the prepreg 2, but for example, the heating temperature is 170°C or higher and 210°C or lower, the pressing pressure is 0.5 MPa or higher and 3.0 MPa or lower, and the time is 60 minutes or higher and 120 minutes or lower.

[0062] When the laminate 3 is heat-pressed in this manner, the resin layer 1 and the prepreg 2 melt and then harden, producing an insulating layer 6 made of the hardened resin layer 1 and the prepreg 2. At this time, the prepreg 2 containing the substrate is not in direct contact with the conductor wiring 41, but rather the resin layer 1 not containing the substrate is in contact with it, so the resin layer 1 flows and easily fills the gaps in the conductor wiring 41. This makes it less likely that gaps will be left unfilled between the insulating layer 6 and the conductor wiring 41. Furthermore, components in the resin layer 1 are less likely to flow out during heat-pressing. This makes it easier to form the insulating layer 6 well even when the conductor wiring 41 is thick.

[0063] As a result, as shown in Figure 3B, a printed wiring board 5 is obtained, which comprises an insulating layer 42 derived from the core material 4, conductive wiring 41 derived from the core material 4, and an insulating layer 6 made from the resin layer 1 and the prepreg 2, which are laminated in the above order.

[0064] The configuration of printed wiring board 5 made from resin layer 1 is not limited to the above. For example, in the above description, printed wiring board 5 includes insulating layer 6 made from resin layer 1 and a cured product of prepreg 2, but insulating layer 6 may be made from resin layer 1 alone, i.e., printed wiring board 5 may include insulating layer 6 made from a cured product of resin layer 1. Printed wiring board 5 may also include a plurality of insulating layers, three or more layers, in which case at least one of the plurality of insulating layers may include a cured product of resin layer 1 (i.e., a cured product of composition (X)). [Example]

[0065] More specific examples of this embodiment will be described below, but this embodiment is not limited to the following examples.

[0066] (1) Preparation of the composition A composition was prepared by mixing the components shown in the "Composition" column of Table 1. Details of the components are as follows. Liquid bisphenol A epoxy resin: DIC, product number Epicron 850-S, viscosity at 25°C 14,000 mPa·s, equivalent weight 190. Liquid bisphenol F epoxy resin: DIC, product number Epicron 830-S, viscosity at 25°C 3500 mPa·s, equivalent weight 170. Solid epoxy resin: DIC, product number Epiclon HP-4710, equivalent weight 170. ·DICY: Dicyandiamide, equivalent weight 21. Zinc octoate. Silica: Made by Admatechs, product number SO-25R. Aluminum hydroxide: Kawai Lime Industry Co., Ltd., product number ALH-F. OP935: Metal phosphinate, manufactured by Clariant, product name EXOLIT OP935, thermal decomposition temperature 300°C or higher. OP930: Metal phosphinate, manufactured by Clariant, product name EXOLIT OP930, thermal decomposition temperature 300°C or higher. OP1230: Metal phosphinate, manufactured by Clariant, product name EXOLIT OP1230, thermal decomposition temperature 300°C or higher. OP1312: Metal phosphinate, manufactured by Clariant, product name EXOLIT OP1312, thermal decomposition temperature 300°C or higher. PX-200: Phosphate ester compound, manufactured by Daihachi Chemical Industry Co., Ltd., product number PX-200, melting point 90°C. FP-100: Phosphazene compound, manufactured by Fushimi Pharmaceutical Co., Ltd., product name: Lavitol FP-100, melting point: 110°C.

[0067] (2) Preparation of resin film material A silicone-coated film (product number SP-PET, thickness 74 μm) manufactured by Mitsui Chemicals Tohcello Co., Ltd. was used as the carrier film. The composition was applied to this carrier film and then heated at 80°C for 1.5 minutes, then at 100°C for 1.5 minutes, and then at 150°C for 1.5 minutes. This produced a resin layer with a thickness of 200 μm and a volatile content of 0.8% by mass. This resulted in a resin film material comprising a carrier film and a resin layer supported thereon. In the case of Comparative Example 3, the resin layer cracked immediately after heating and therefore could not be evaluated.

[0068] (3) Manufacturing of printed wiring boards A core material was prepared with an insulating layer of 200 μm thickness and a conductor wiring of 400 μm thickness overlaid on the insulating layer. The conductor wiring had a line width of 800 μm, a space width of 1000 μm, and a copper remaining ratio of 50%.

[0069] Furthermore, as a prepreg, a product name: R-1551(S) (resin component: epoxy resin, base material: glass cloth (glass cloth style 2116)) manufactured by Panasonic Corporation was prepared.

[0070] A laminate was obtained by placing one resin layer of a resin film material on the conductor wiring of the core material, and then placing two prepregs on top of that. This laminate was then heat-pressed. The heating temperature during the heat press was first increased from 30°C to 200°C at a rate of 2°C / min, and then held at 200°C for 120 minutes. The pressing pressure was 0.5 MPa for the first 60 minutes and 2.0 MPa for the next 145 minutes. This resulted in a printed wiring board having an insulating layer derived from the core material, conductor wiring, and an insulating layer made from the frost layer and prepreg.

[0071] (4) Evaluation (4-1) Melt Viscosity at 150°C The melt viscosity of the resin layer at 150°C was measured using a viscoelasticity measuring device (Soliquid Meter, manufactured by UBM, model number Reosol-G3000).

[0072] For the measurements, a sample with a diameter of 10 mm and a thickness of 3 mm was prepared by compression molding the resin layer. As a pretreatment step, the sample was placed on a 31 mm diameter plate and heated to 80°C at a heating rate of 190°C / min while applying a load of 1000 g to the sample. It was then rapidly cooled to below 30°C, thereby adhering the sample to the plate. The melt viscosity of the sample at 150°C was then measured under conditions of a load of 1000 g, a frequency of 10 Hz, and an angular velocity of 0.5 rad / sec.

[0073] (4-2)Flame resistance The flame resistance of the insulating layer made of the resin layer and the prepreg was evaluated by a combustion test in accordance with UL94.

[0074] (4-3) Runoff The cross section of the printed wiring board was observed to check the thickness of the cured resin layer overlapping the conductor wiring. If the thickness was 20 μm or more, it was rated as "A," and if not, it was rated as "C."

[0075] (4-4) R-10 bending evaluation The resin film material was wrapped around a cylinder with a diameter of 10 mm. As a result, if no cracks occurred in the resin layer of the resin film material, it was rated as "A", and if cracks occurred, it was rated as "C".

[0076] (4-5) Powder shedding evaluation The resin film material was cut with a cutter knife. If the resulting cut surface crumbled and powder fell off, it was rated as "C," if powder fall was observed but only in small amounts, it was rated as "B," and if the cut surface did not crumble and no powder fall was observed, it was rated as "A."

[0077] (4-6) Fillability The cross section of the printed wiring board was observed to check for the presence or absence of voids in the insulating layer made of the resin layer and prepreg. As a result, if no voids were observed, it was rated as "A", and if voids were observed, it was rated as "C".

[0078] [Table 1]

[0079] [Table 2] [Explanation of symbols]

[0080] 1 resin layer 10 Resin film material 3 Laminate 6 insulating layer 4 Core material 41 Conductor wiring 42 Insulating layer 5. Printed wiring board 7. Carrier Film

Claims

1. Contains a resin component (A) and a phosphorus-containing flame retardant (B), the resin component (A) contains an epoxy resin (a1) having a viscosity of 50,000 mPa s or less at 25°C, and the ratio of the epoxy resin (a1) to the resin component (A) is 20% by mass or more and 40% by mass or less; The resin component (A) further contains an epoxy resin (a2) that is solid at 25°C, The phosphorus-containing flame retardant (B) contains a phosphorus-containing flame retardant (B1) that does not melt or thermally decompose at temperatures below 150°C. For the manufacture of printed wiring boards, Resin composition.

2. The resin component (A) further contains at least one of a curing agent (b) and a curing accelerator (c). The resin composition according to claim 1.

3. The ratio of the phosphorus-containing flame retardant (B1) to the resin component (A) is 3% by mass or more and 10% by mass or less. The resin composition according to claim 1 or 2.

4. The ratio of the phosphorus-containing flame retardant (B1) to the phosphorus-containing flame retardant (B) is 30 mass% or more. The resin composition according to any one of claims 1 to 3.

5. The proportion of the phosphorus-containing flame retardant (B) relative to the entire resin composition is 1% by mass or more and 5% by mass or less. The resin composition according to any one of claims 1 to 4.

6. Further containing an inorganic filler, The resin composition according to any one of claims 1 to 5.

7. The proportion of the inorganic filler relative to the entire resin composition is 60% by mass or more and 90% by mass or less. The resin composition according to claim 6.

8. A carrier film and a resin layer overlying the carrier film and containing an uncured or semi-cured product of the resin composition according to any one of claims 1 to 7. Resin film material.

9. The resin layer has a thickness of 50 μm or more and 400 μm or less. The resin film material according to claim 8.

10. The melt viscosity of the resin layer at 150°C is 400 Pa s or more. The resin film material according to claim 8 or 9.

11. A conductive wiring and an insulating layer overlapping the conductive wiring, A printed wiring board, wherein the insulating layer comprises a cured product of the resin composition according to claim 1 .

12. The method includes hot pressing a laminate including a core material having conductor wiring and the resin layer of the resin film material according to any one of claims 8 to 10. A method for manufacturing a printed wiring board.

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