JP2017110104A - Prepreg - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prepreg which improves handleability, embedding properties and a copper plating peeling strength, and prevents occurrence of warpage; a printed wiring board using the same; and a semiconductor device.SOLUTION: There is provided a prepreg which contains a sheet-like fiber base material and a resin composition impregnated in the sheet-like fiber base material, where the resin composition contains (a) elastomer, (b) a thermosetting resin having an aromatic structure and (c) an inorganic filer, and an average maximum length of a domain contained in a cured product obtained by thermosetting the resin composition is 15 μm or less.SELECTED DRAWING: None

Description

  The present invention relates to a prepreg. Furthermore, the present invention relates to a printed wiring board using a prepreg and a semiconductor device.

  As a method of manufacturing a wiring board (printed wiring board), a build-up method in which a circuit-formed conductor layer and an insulating layer are alternately stacked is widely used, and the insulating layer is formed by curing a prepreg. And those formed by curing a resin composition are known (see, for example, Patent Document 1).

JP2015-82535A

  In recent years, in the production of printed wiring boards, there has been an increasing demand for improvement in prepreg handling properties, embedding properties, peel strength, and the like. Moreover, the request | requirement of suppressing the curvature which generate | occur | produces when forming an insulating layer using a prepreg is also increasing.

  An object of the present invention has been made to solve the above-described problems, and handling properties, embedding properties, and copper plating peel strength are improved, and a prepreg that does not generate warpage, a printed wiring board using the prepreg, And providing a semiconductor device.

That is, the present invention includes the following contents.
[1] A sheet-like fiber base material, and a resin composition impregnated in the sheet-like fiber base material,
The resin composition contains (a) an elastomer, (b) a thermosetting resin having an aromatic structure, and (c) an inorganic filler,
A prepreg having an average maximum domain length of 15 μm or less, which is contained in a cured product obtained by thermosetting a resin composition.
[2] The prepreg according to [1], wherein the resin composition includes (d) organic particles.
[3] The component (a) is at least one selected from resins having a functional group capable of reacting with the component (b) and having a glass transition temperature of 25 ° C. or lower or 25 ° C. Or the prepreg according to [2].
[4] The component (a) is a butadiene structural unit, a polysiloxane structural unit, a (meth) acrylate structural unit, an alkylene structural unit, an alkyleneoxy structural unit, an isoprene structural unit, an isobutylene structural unit, a chloroprene structural unit, a urethane structural unit, The prepreg according to any one of [1] to [3], which has at least one structural unit selected from polycarbonate structural units.
[5] The prepreg according to any one of [1] to [4], which contains an epoxy resin that is solid at a temperature of 20 ° C. as the component (b).
[6] As a component (b), a liquid epoxy resin at a temperature of 20 ° C. and a solid epoxy resin at a temperature of 20 ° C. are used, and the mass ratio of the liquid epoxy resin to the solid epoxy resin is 1: 0.3 to The prepreg according to any one of [1] to [5], which is 1:10.
[7] The prepreg according to [5] or [6], which does not contain a resin having a naphthalene skeleton and having a molecular weight of 400 or more as a solid epoxy resin at a temperature of 20 ° C.
[8] When the mass of the component (a) in the resin composition is A and the mass of the component (b) is B, (A / (A + B)) × 100 is 20 to 70, [1] to [1] 7] The prepreg according to any one of [7].
[9] The prepreg according to any one of [1] to [8], wherein the content of the component (c) is 25 to 70% by mass when the nonvolatile component in the resin composition is 100% by mass.
[10] When the mass of the component (a) in the resin composition is A, the mass of the component (b) is B, and the mass of the component (d) is D, (D / (A + B + D)) × 100 is 10 or less. The prepreg according to any one of [2] to [9].
[11] The prepreg according to any one of [1] to [10], which is for forming an insulating layer of a printed wiring board.
[12] The prepreg according to any one of [1] to [11], which is for forming a buildup layer of a printed wiring board.
[13] A printed wiring board including an insulating layer formed by the prepreg according to any one of [1] to [12].
[14] A semiconductor device comprising the printed wiring board according to [13].

  According to the present invention, it is possible to provide a prepreg in which handling properties, embedding properties, and copper plating peel strength are improved and warpage is not generated, a printed wiring board using the prepreg, and a semiconductor device.

1 is a cross-sectional photograph of a cured product of the prepreg of Example 1. FIG. FIG. 2 is a cross-sectional photograph of a cured product of the prepreg of Example 2. FIG. 3 is a cross-sectional photograph of a cured product of the prepreg of Comparative Example 1.

  Hereinafter, the prepreg, printed wiring board, and semiconductor device of the present invention will be described in detail.

[Prepreg]
The prepreg of the present invention includes a sheet-like fiber base material and a resin composition impregnated in the sheet-like fiber base material, and the resin composition has (a) an elastomer and (b) a thermosetting resin having an aromatic structure. A resin and (c) an inorganic filler are contained, and the average maximum length of domains contained in a cured product obtained by thermosetting the resin composition is 15 μm or less.

  From the viewpoint of improving the prepreg handling properties, embedding properties, copper plating peel strength, etc., the average maximum length of the domain contained in the cured product obtained by thermosetting the resin composition is preferably 15 μm or less, 10 μm or less, 5 μm or less is more preferable, and it is further preferable that no confirmation can be made (no domain exists). By setting the average maximum length of the domain to 15 μm or less, the prepreg embedding property can be improved.

  The average maximum length of the domain can be measured as follows. A prepreg thermally cured under the conditions of 100 ° C. for 30 minutes and then 170 ° C. for 30 minutes was subjected to cross-sectional observation using a FIB-SEM composite device (“SMI3050SE” manufactured by SII Nanotechnology Co., Ltd.). . Specifically, a cross section in a direction perpendicular to the surface of the prepreg was cut out by FIB (focused ion beam), and a cross-sectional SEM image (observation width 60 μm, observation magnification 2,000 times) was obtained. Randomly selected cross-sectional SEM images at five locations were observed, the largest domain existing in the cross-sectional SEM image was selected, the maximum length of each selected domain was measured, and the average value was taken as the average maximum length. The maximum length means the length of the longest straight line among straight lines that can be drawn in the domain region. In the cured product obtained by thermosetting the resin composition, the components of the resin composition may not be uniformly mixed and may be unevenly distributed. When a cross-sectional SEM image of the cured product in which such component components are unevenly distributed is observed, a sea-island structure resulting from the uneven distribution of the component components is observed. In the present invention, a domain refers to an island portion of such a sea-island structure.

  Although details will be described later, when the wiring board is manufactured, the wiring layer is embedded in the prepreg of the present invention, thereby forming an embedded wiring layer. In the prepreg of the present invention, handling properties, embedding properties, and copper plating peel strength are improved, and from the viewpoint of suppressing the occurrence of warpage, the resin composition comprises (a) an elastomer and (b) a heat having an aromatic structure. It contains a curable resin and (c) an inorganic filler. The resin composition further contains additives such as (d) organic particles, (e) a curing agent, (f) a curing accelerator, (g) a thermoplastic resin, and (h) a flame retardant, as necessary. May be. Hereinafter, each component contained in the resin composition will be described in detail.

(Resin composition)
<(A) Elastomer>
The resin composition contains the component (a). By including a flexible resin such as the component (a), the prepreg handling properties, embedding properties, and copper plating peel strength can be improved, and the occurrence of warpage and the like can be further suppressed.

  The component (a) is not particularly limited as long as it is a flexible resin, but preferably has a functional group capable of reacting with the component (b) described later. Among these, a resin having a glass transition temperature of 25 ° C. or lower or a liquid at 25 ° C. and one or more selected from resins having a functional group capable of reacting with the component (b) is preferable.

  The glass transition temperature of the resin having a glass transition temperature (Tg) of 25 ° C. or lower is preferably 20 ° C. or lower, more preferably 15 ° C. or lower. Although the minimum of a glass transition temperature is not specifically limited, Usually, it can be set as -15 degreeC or more. The resin that is liquid at 25 ° C. is preferably a resin that is liquid at 20 ° C. or lower, more preferably a resin that is liquid at 15 ° C. or lower.

  In a preferred embodiment, the functional group capable of reacting with the component (b) is one or more selected from the group consisting of a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a urethane group. It is a functional group. Among these, as the functional group, a hydroxyl group, an acid anhydride group, an epoxy group, and a phenolic hydroxyl group are preferable, and a hydroxyl group, an acid anhydride group, and an epoxy group are more preferable. However, when an epoxy group is included as a functional group, the thermosetting resin having an aromatic structure is not included as the component (a) for distinction from the component (b).

  Component (a) is a butadiene structural unit such as polybutadiene and hydrogenated polybutadiene, a polysiloxane structural unit such as silicone rubber, a (meth) acrylate structural unit, and the number of carbon atoms from the viewpoint of improving the handling properties of the prepreg of the present invention. 2 to 15 alkylene structural units (preferably 3 to 10 carbon atoms, more preferably 5 to 6 carbon atoms), 2 to 15 alkyleneoxy structural units (preferably 3 to 10 carbon atoms, and more) Preferably, it has one or more structural units selected from 5 to 6 carbon atoms, isoprene structural units, isobutylene structural units, chloroprene structural units, urethane structural units, and polycarbonate structural units. 1 or more selected from structural units and (meth) acrylate structural units And more preferably has a structural unit. “(Meth) acrylate” refers to methacrylate and acrylate.

  A preferred embodiment of the component (a) is a functional group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C. Examples of the functional group-containing saturated and / or unsaturated butadiene resins that are liquid at 25 ° C. include acid anhydride group-containing saturated and / or butadiene resins that are liquid at 25 ° C., and phenolic hydroxyl group-containing saturated and / or butadiene that are liquid at 25 ° C. Group consisting of resin, epoxy group-containing saturated and / or butadiene resin that is liquid at 25 ° C., isocyanate group-containing saturated and / or butadiene resin that is liquid at 25 ° C., and urethane group-containing saturated and / or butadiene resin that is liquid at 25 ° C. One or more resins selected from are preferred. Here, the “saturated and / or unsaturated butadiene resin” means a resin containing a saturated butadiene skeleton and / or an unsaturated butadiene skeleton, and in these resins, the saturated butadiene skeleton and / or the unsaturated butadiene skeleton is a main chain. Or may be contained in the side chain.

  The number average molecular weight (Mn) of the functional group-containing saturated and / or unsaturated butadiene resin which is liquid at 25 ° C. is preferably 500 to 50,000, more preferably 1000 to 10,000. Here, the number average molecular weight (Mn) of the resin is a number average molecular weight in terms of polystyrene measured using GPC (gel permeation chromatography).

  The functional group equivalent of the liquid functional group-containing saturated and / or unsaturated butadiene resin at 25 ° C. is preferably 100 to 10,000, more preferably 200 to 5,000. In addition, functional group equivalent is the mass of resin containing 1 equivalent of functional groups. For example, the epoxy equivalent of the resin can be measured according to JIS K7236.

  The epoxy group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C. is preferably a liquid saturated and / or butadiene skeleton-containing epoxy resin that is liquid at 25 ° C., and a polybutadiene skeleton-containing epoxy resin that is liquid at 25 ° C. A liquid hydrogenated polybutadiene skeleton-containing epoxy resin is more preferable, and a polybutadiene skeleton-containing epoxy resin that is liquid at 25 ° C. and a hydrogenated polybutadiene skeleton-containing epoxy resin that is liquid at 25 ° C. are more preferable. Here, the “hydrogenated polybutadiene skeleton-containing epoxy resin” refers to an epoxy resin in which at least a part of the polybutadiene skeleton is hydrogenated, and is not necessarily an epoxy resin in which the polybutadiene skeleton is completely hydrogenated. Specific examples of the polybutadiene skeleton-containing resin that is liquid at 25 ° C. and the hydrogenated polybutadiene skeleton-containing resin that is liquid at 25 ° C. include “PB3600” and “PB4700” (polybutadiene skeleton epoxy resin) manufactured by Daicel Corporation, Nagase ChemteX Corporation. "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Co., Ltd. and the like can be mentioned.

  The acid anhydride group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C. is preferably a saturated and / or unsaturated butadiene skeleton-containing acid anhydride resin that is liquid at 25 ° C. The phenolic hydroxyl group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C. is preferably a saturated and / or unsaturated butadiene skeleton-containing phenol resin that is liquid at 25 ° C. The isocyanate group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C. is preferably a saturated and / or unsaturated butadiene skeleton-containing isocyanate resin that is liquid at 25 ° C. As the urethane group-containing saturated and / or unsaturated butadiene resin that is liquid at 25 ° C., a saturated and / or unsaturated butadiene skeleton-containing urethane resin that is liquid at 25 ° C. is preferable.

  Another preferred embodiment of the component (a) is a functional group-containing acrylic resin having a Tg of 25 ° C. or lower. The functional group-containing acrylic resin having a Tg of 25 ° C. or lower includes an acid anhydride group-containing acrylic resin having a Tg of 25 ° C. or lower, a phenolic hydroxyl group-containing acrylic resin having a Tg of 25 ° C. or lower, and an isocyanate group containing Tg of 25 ° C. One or more resins selected from the group consisting of an acrylic resin, a urethane group-containing acrylic resin having a Tg of 25 ° C. or lower, and an epoxy group-containing acrylic resin having a Tg of 25 ° C. or lower are preferred.

  The number average molecular weight (Mn) of the functional group-containing acrylic resin having a Tg of 25 ° C. or lower is preferably 10,000 to 1,000,000, more preferably 30,000 to 900,000. Here, the number average molecular weight (Mn) of the resin is a number average molecular weight in terms of polystyrene measured using GPC (gel permeation chromatography).

  The functional group equivalent of the functional group-containing acrylic resin having a Tg of 25 ° C. or lower is preferably 1000 to 50000, more preferably 2500 to 30000.

  The epoxy group-containing acrylic resin having a Tg of 25 ° C. or lower is preferably an epoxy group-containing acrylic ester copolymer resin having a Tg of 25 ° C. or lower. Specific examples thereof include “SG-” manufactured by Nagase ChemteX Corporation. 80H "(epoxy group-containing acrylate copolymer resin (number average molecular weight Mn: 350,000 g / mol, epoxy value 0.07 eq / kg, Tg11 ° C))," SG-P3 "(manufactured by Nagase ChemteX Corporation) ( Epoxy group-containing acrylic ester copolymer resin (number average molecular weight Mn: 850000 g / mol, epoxy value 0.21 eq / kg, Tg 12 ° C.)).

  The acid anhydride group-containing acrylic resin having a Tg of 25 ° C. or lower is preferably an acid anhydride group-containing acrylic ester copolymer resin having a Tg of 25 ° C. or lower.

  As the phenolic hydroxyl group-containing acrylic resin having a Tg of 25 ° C. or lower, a phenolic hydroxyl group-containing acrylic ester copolymer resin having a Tg of 25 ° C. or lower is preferable. Specific examples thereof include “manufactured by Nagase ChemteX Corporation” SG-790 "(epoxy group-containing acrylic ester copolymer resin (number average molecular weight Mn: 500,000 g / mol, hydroxyl value 40 mg KOH / kg, Tg-32 ° C)).

  Moreover, suitable one Embodiment of (a) component is a polyimide resin which has a butadiene structural unit, a urethane structural unit, and an imide structural unit in a molecule | numerator, It is preferable that this polyimide resin has a phenol structure at the molecule terminal. .

  The number average molecular weight (Mn) of the polyimide resin is preferably 1000 to 100,000, more preferably 10,000 to 15000. Here, the number average molecular weight (Mn) of the resin is a number average molecular weight in terms of polystyrene measured using GPC (gel permeation chromatography).

  The acid value of the polyimide resin is preferably 1 KOH / g to 30 KOH / g, more preferably 10 KOH / g to 20 KOH / g.

  The content of the butadiene structure in the polyimide resin is preferably 60% by mass to 95% by mass, and more preferably 75% by mass to 85% by mass.

  Details of the polyimide resin can be referred to the description of International Publication No. 2008/153208, the contents of which are incorporated herein.

  Although content of (a) component in a resin composition is not specifically limited, Preferably it is 80 mass% or less, More preferably, it is 50 mass% or less, More preferably, it is 45 mass% or less. The lower limit is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 25% by mass or more.

  In addition, in this invention, content of each component in a resin composition is a value when the non-volatile component in a resin composition is 100 mass% unless there is separate description.

<(B) Thermosetting resin having aromatic structure>
(B) As the thermosetting resin having an aromatic structure, a conventionally known thermosetting resin used for forming an insulating layer of a wiring board can be used, and among them, an epoxy resin having an aromatic structure is used. More preferred.

  The epoxy resin having an aromatic structure (hereinafter also simply referred to as “epoxy resin”) is not particularly limited as long as it has an aromatic structure. The aromatic structure is a chemical structure generally defined as aromatic, and includes polycyclic aromatics and aromatic heterocycles. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolak type epoxy resin, Phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin having aromatic structure, glycidyl ester type epoxy having aromatic structure Resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin having aromatic structure, butadiene structure having aromatic structure Epoxy resin, alicyclic epoxy resin having aromatic structure, heterocyclic epoxy resin, spiro ring-containing epoxy resin having aromatic structure, cyclohexanedimethanol type epoxy resin having aromatic structure, naphthylene ether type epoxy resin And trimethylol type epoxy resin having an aromatic structure, tetraphenylethane type epoxy resin and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. The component (b) is preferably at least one selected from bisphenol A type epoxy resins, bisphenol F type epoxy resins, and biphenyl type epoxy resins.

  The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the nonvolatile component of the epoxy resin is 100% by mass, at least 50% by mass or more is preferably an epoxy resin having two or more epoxy groups in one molecule. Among them, it is preferable to contain a solid epoxy resin (hereinafter referred to as “solid epoxy resin”) at a temperature of 20 ° C., and further contains a liquid epoxy resin (hereinafter referred to as “liquid epoxy resin”) at a temperature of 20 ° C. May be.

  Solid epoxy resins include naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin having an aromatic structure, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene. Ether type epoxy resin, anthracene type epoxy resin, bisphenol A type epoxy resin, bisphenol AF type epoxy resin, tetraphenylethane type epoxy resin are preferable, naphthalene type tetrafunctional epoxy resin, naphthol type epoxy resin, and biphenyl type epoxy resin, naphthy A renether type epoxy resin is more preferable, and a naphthalene type tetrafunctional epoxy resin and a naphthylene ether type epoxy resin are more preferable. Specific examples of the solid epoxy resin include “HP4032H” (naphthalene type epoxy resin), “HP-4700”, “HP-4710” (naphthalene type tetrafunctional epoxy resin), “N-690” manufactured by DIC Corporation. "(Cresol novolac type epoxy resin)", "N-695" (Cresol novolac type epoxy resin), "HP-7200", "HP-7200L", "HP-7200HH", "HP-7200H", "HP-7200HHH "(Dicyclopentadiene type epoxy resin)", "EXA7311", "EXA7311-G3", "EXA7311-G4", "EXA7311-G4S", "HP6000" (naphthylene ether type epoxy resin), Nippon Kayaku Co., Ltd. “EPPN-502H” (trisphenol type epoxy resin), “ C7000L "(naphthol novolac type epoxy resin)," NC3000H "," NC3000 "," NC3000L "," NC3100 "(biphenyl type epoxy resin)," ESN475V "(naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. “ESN485” (naphthol novolak type epoxy resin), “YX4000H”, “YL6121” (biphenyl type epoxy resin), “YX4000HK” (bixylenol type epoxy resin), “YL7760” (bisphenol AF type) manufactured by Mitsubishi Chemical Corporation Epoxy resin), "YX8800" (anthracene type epoxy resin), "PG-100", "CG-500" manufactured by Osaka Gas Chemical Co., Ltd., "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation , Mitsubishi Chemical Corporation “JER1010” (solid bisphenol A type epoxy resin), “jER1031S” (tetraphenylethane type epoxy resin), “157S70” (bisphenol novolak type epoxy resin) manufactured by Mitsubishi Chemical Corporation, “YX4000HK” (Bi Xylenol type epoxy resin), “YX8800” (anthracene type epoxy resin), “PG-100”, “CG-500” manufactured by Osaka Gas Chemical Co., Ltd., “YL7800” (fluorene type epoxy manufactured by Mitsubishi Chemical Corporation) Resin), “jER1031S” (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation, and the like. These may be used alone or in combination of two or more.

From the viewpoint of setting the average maximum length of the domain to 15 μm or less, the solid epoxy resin preferably does not contain a resin having a molecular weight of 400 or more having a naphthalene skeleton (not containing a resin having a molecular weight of 350 or more having a naphthalene skeleton). It is more preferable that it does not contain a resin having a naphthalene skeleton. The solid epoxy resin preferably does not contain a resin having a triphenyl skeleton. Further, the solid epoxy resin preferably does not contain a bisphenol novolac resin. Further, the solid epoxy resin preferably does not contain an epoxy resin having a biphenyl skeleton and a molecular weight of 1000 or more (more preferably, it does not contain a resin having a biphenyl skeleton).
Further, the solid epoxy resin is selected from an epoxy resin having an alicyclic structure (for example, a dicyclopentadiene type epoxy resin), a resin containing a xylene skeleton, a cresol novolac type epoxy resin, and a tetraphenylethane type epoxy resin. It is preferable to contain 1 or more types, and it is more preferable to contain an epoxy resin having an alicyclic structure.

  Examples of liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins having an aromatic structure, and glycidyl amine type epoxy resins having an aromatic structure. Phenol novolac type epoxy resin, alicyclic epoxy resin having ester skeleton having aromatic structure, cyclohexanedimethanol type epoxy resin having aromatic structure and epoxy resin having butadiene structure having aromatic structure are preferable, and bisphenol A Type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin and naphthalene type epoxy resin are more preferable, bisphenol A type epoxy resin, bisphenol F type epoxy Shi resin is more preferred. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC Corporation, “828US”, “jER828EL” (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "630", "630LSD" (glycidylamine type epoxy resin), manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. "ZX1059" (mixed product of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, "Celoxide 2021P" manufactured by Daicel Corporation "(Fat having an ester skeleton) Wherein the epoxy resin), Nippon Steel Chemical Co., Ltd. "ZX1658", "ZX1658GS" (liquid 1,4 glycidyl cyclohexane) and the like. These may be used alone or in combination of two or more.

  The liquid epoxy resin is preferably an epoxy resin having two or more epoxy groups in one molecule and having a liquid aromatic ring structure at a temperature of 20 ° C., and the solid epoxy resin has three or more epoxy in one molecule. An epoxy resin having a group and having a solid aromatic ring structure at a temperature of 20 ° C. is preferred.

  By using a liquid epoxy resin, the handling property and the resin flow of the prepreg can be improved, and by using the solid epoxy resin, heat resistance, electrical characteristics, and the like can be improved while suppressing tackiness of the prepreg. When both liquid epoxy resin and solid epoxy resin are used together as an epoxy resin to give both effects of liquid epoxy resin and solid epoxy resin, the quantitative ratio (liquid epoxy resin: solid epoxy resin) is The mass ratio is preferably in the range of 1: 0.1 to 1:20. From the viewpoint of obtaining the above effect, the mass ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is more preferably in the range of 1: 0.3 to 1:10. : The range of 0.6-1: 9 is further more preferable.

  The content of the epoxy resin in the resin composition is preferably 4% by mass or more, more preferably 5% by mass or more, and further preferably 6% by mass from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. That's it. Although the upper limit of content of an epoxy resin is not specifically limited as long as the effect of this invention is show | played, Preferably it is 50 mass% or less, More preferably, it is 30 mass% or less.

  From the viewpoint of suppressing warping of the prepreg, when the mass of the component (a) is A and the mass of the component (b) is B, A / (A + B) × 100 is preferably 20 to 70, more preferably 30 to 68. 35 to 65 are more preferable. Warpage can be effectively suppressed by setting A / (A + B) × 100 to 20 to 70.

  The epoxy equivalent of the epoxy resin is preferably 50 to 5000, more preferably 50 to 3000, still more preferably 80 to 2000, and even more preferably 110 to 1000. By becoming this range, the crosslinked density of hardened | cured material becomes sufficient and it can bring about an insulating layer with small surface roughness. The epoxy equivalent can be measured according to JIS K7236, and is the mass of a resin containing 1 equivalent of an epoxy group.

  The weight average molecular weight of an epoxy resin becomes like this. Preferably it is 100-5000, More preferably, it is 250-3000, More preferably, it is 400-1500. Here, the weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a gel permeation chromatography (GPC) method. The molecular weight of 1000 or less can be measured by GC / MS (gas chromatography mass spectrometry).

<(C) Inorganic filler>
The material of the inorganic filler is not particularly limited. For example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, water Aluminum oxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide , Zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Of these, silica is particularly preferred. As silica, spherical silica is preferable. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type.

  The average particle diameter of the inorganic filler is preferably 2 μm or less, more preferably 1.5 μm or less, still more preferably 1.2 μm or less, and more preferably 1 μm or less from the viewpoint of good embedding properties. Although the minimum of this average particle diameter is not specifically limited, Preferably it is 0.01 micrometer or more, More preferably, it is 0.05 micrometer or more, More preferably, it is 0.1 micrometer or more. Examples of commercially available inorganic fillers having such an average particle size include, for example, “YC100C”, “YA050C”, “YA050C-MJE”, “YA010C” manufactured by Admatechs, manufactured by Denki Kagaku Kogyo Co., Ltd. “UFP-30”, “Silfil NSS-3N”, “Silfil NSS-4N”, “Silfil NSS-5N” manufactured by Tokuyama Corporation, “SOC4”, “SOC2”, “SOC1” manufactured by Admatechs Corporation Examples include “BMB-05” manufactured by Kawai Lime Industry Co., Ltd.

  The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction / scattering particle size distribution measuring apparatus, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering particle size distribution measuring apparatus, “LA-500” manufactured by Horiba, Ltd. or the like can be used.

  Inorganic fillers are aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents from the viewpoint of improving moisture resistance and dispersibility. It is preferable that it is processed with 1 or more types of surface treating agents. Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM803” (3-mercaptopropyltrimethoxy manufactured by Shin-Etsu Chemical Co., Ltd.). Silane), Shin-Etsu Chemical "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical "SZ-31" (hexamethyldisilazane) manufactured by KK, "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. (long-chain epoxy type) Silane coupling agent).

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. Carbon content per unit surface area of the inorganic filler, from the viewpoint of improving dispersibility of the inorganic filler is preferably 0.02 mg / ^{m 2} or more, 0.1 mg / ^{m 2} or more preferably, 0.2 mg / ^{m 2} The above is more preferable. On the other hand, 1 mg / m ² or less is preferable, 0.8 mg / m ² or less is more preferable, and 0.5 mg / m ² or less is more preferable from the viewpoint of preventing an increase in the melt viscosity of the resin varnish or the sheet form. preferable.

  The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent and ultrasonically cleaned at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid, the carbon amount per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, “EMIA-320V” manufactured by Horiba, Ltd. can be used.

  The content of the inorganic filler in the resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably 25% by mass or more from the viewpoint of obtaining an insulating layer having a low coefficient of thermal expansion. The upper limit of the content of the inorganic filler in the resin composition is preferably 80% by mass or less, more preferably 70% by mass or less, and still more preferably 65% by mass or less from the viewpoint of mechanical strength of the insulating layer, particularly elongation. is there.

<(D) Organic particles>
As the resin composition, any organic particles (also referred to as an organic filler) that can be used for forming an insulating layer of a printed wiring board may be used. Examples thereof include rubber particles, polyamide fine particles, and silicone particles. . In addition, as (d) component, it is preferable not to have the functional group in (a) component. The component (d) preferably has a solubility in methyl ethyl ketone of less than 5 (g / 100 g) at 25 ° C.

  The average particle diameter of the organic particles is preferably 2 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less. Although there is no restriction | limiting in particular about a minimum, it is 0.01 micrometer or more. The average particle size is an average value obtained by measuring each organic particle 50 times using a laser diffraction / scattering particle size distribution measuring device or the like.

  As the rubber particles, commercially available products may be used. Examples thereof include “EXL-2655” manufactured by Dow Chemical Japan Co., Ltd., “AC3816N” manufactured by Ganz Kasei Co., Ltd., and the like.

  When the resin composition contains organic particles, the content of the organic particles is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 10% by mass, and still more preferably 0.3% by mass. % To 5% by mass, or 0.5% to 4% by mass.

  When the mass of the component (a) in the resin composition is A, the mass of the component (b) is B, and the mass of the component (d) is D, (D / (A + B + D)) × 100 is preferably 10 or less. 8 or less is more preferable, and 5 or less is more preferable. By setting (D / (A + B + D)) × 100 to 10 or less, phase separation of each component is suppressed, and the average maximum length of the domains can be 15 μm or less. When the component (d) is blended (that is, when D is not 0), the lower limit of (D / (A + B + D)) × 100 is preferably 1 or more.

<(E) Curing agent>
The curing agent is not particularly limited as long as it has a function of curing a thermosetting resin such as an epoxy resin. For example, a phenol curing agent, a naphthol curing agent, an active ester curing agent, a benzoxazine curing agent, and a cyanate. Examples include ester-based curing agents and carbodiimide-based curing agents. A hardening | curing agent may be used individually by 1 type, or may use 2 or more types together. The component (e) is preferably at least one selected from a phenolic curing agent, a naphthol curing agent, an active ester curing agent, and a cyanate ester curing agent.

  As the phenol-based curing agent and the naphthol-based curing agent, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is preferable from the viewpoint of heat resistance and water resistance. Further, from the viewpoint of adhesion to the wiring layer, a nitrogen-containing phenol-based curing agent is preferable, and a triazine skeleton-containing phenol-based curing agent is more preferable. Among these, a triazine skeleton-containing phenol novolac curing agent is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to the wiring layer.

  Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, “MEH-7700”, “MEH-7810”, “MEH-7785” manufactured by Meiwa Kasei Co., Ltd., and Nippon Kayaku Co., Ltd. “NHN”, “CBN”, “GPH”, “SN170”, “SN180”, “SN190”, “SN475”, “SN485”, “SN495V”, “SN375”, “SN395” manufactured by Nippon Steel & Sumikin Co., Ltd. "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P", "EXB-9500", "HPC-9500" manufactured by DIC Corporation Etc.

  From the viewpoint of obtaining an insulating layer having excellent adhesion to the wiring layer, an active ester curing agent is also preferable. Although there is no restriction | limiting in particular as an active ester type hardening | curing agent, Generally ester groups with high reaction activity, such as phenol ester, thiophenol ester, N-hydroxyamine ester, ester of heterocyclic hydroxy compound, are in 1 molecule. A compound having two or more in the above is preferably used. The active ester curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and / or a naphthol compound is more preferable. Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Benzenetriol, dicyclopentadiene type diphenol compound, phenol novolac and the like can be mentioned. Here, the “dicyclopentadiene type diphenol compound” refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

  Specifically, an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of a phenol novolac, and an active ester compound containing a benzoylated product of a phenol novolac are preferred, Of these, active ester compounds having a naphthalene structure and active ester compounds having a dicyclopentadiene type diphenol structure are more preferred. The “dicyclopentadiene type diphenol structure” represents a divalent structural unit composed of phenylene-dicyclopentylene-phenylene.

  Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-" as active ester compounds containing a dicyclopentadiene type diphenol structure. 65TM "," EXB-8000L-65TM "(manufactured by DIC Corporation)," EXB9416-70BK "(manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, and as an active ester compound containing an acetylated product of phenol novolac “DC808” (manufactured by Mitsubishi Chemical Corporation), “YLH1026” (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing a benzoylated product of phenol novolac, and “DC808” as an active ester curing agent which is an acetylated product of phenol novolac. "( "YLH1026" (Mitsubishi Chemical Corporation), "YLH1030" (Mitsubishi Chemical Corporation), "YLH1048" (Mitsubishi Chemical Corporation) as active ester-based curing agents that are benzoylated phenol novolaks Chemical Co., Ltd.).

  Specific examples of the benzoxazine-based curing agent include “HFB2006M” manufactured by Showa Polymer Co., Ltd., “Pd” and “Fa” manufactured by Shikoku Kasei Kogyo Co., Ltd.

  Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate, oligo (3-methylene-1,5-phenylene cyanate), 4,4′-methylenebis (2,6-dimethylphenyl cyanate), 4,4. '-Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5-dimethyl) Bifunctional cyanate resins such as phenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, phenol Novolac and K Polyfunctional cyanate resin derived from tetrazole novolac, these cyanate resins and partially triazine of prepolymer. Specific examples of the cyanate ester curing agent include “PT30” and “PT60” (both phenol novolac polyfunctional cyanate ester resins), “BA230”, “BA230S75” (bisphenol A dicyanate) manufactured by Lonza Japan Co., Ltd. For example, a prepolymer partially or wholly converted into a trimer).

  Specific examples of the carbodiimide curing agent include “V-03” and “V-07” manufactured by Nisshinbo Chemical Co., Ltd.

  Although content of the hardening | curing agent in a resin composition is not specifically limited, Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less, More preferably, it is 20 mass% or less. The lower limit is not particularly limited but is preferably 2% by mass or more.

<(F) Curing accelerator>
Examples of the curing accelerator include a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, a guanidine-based curing accelerator, a metal-based curing accelerator, and the like. A curing accelerator, an imidazole curing accelerator, and a metal curing accelerator are preferable, and an amine curing accelerator, an imidazole curing accelerator, and a metal curing accelerator are more preferable. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of phosphorus curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl) triphenylphosphonium thiocyanate. , Tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, and triphenylphosphine and tetrabutylphosphonium decanoate are preferable.

  Examples of amine curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6, -tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo. (5,4,0) -undecene and the like are mentioned, and 4-dimethylaminopyridine and 1,8-diazabicyclo (5,4,0) -undecene are preferable.

  Examples of the imidazole curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl- 2 Phenylimidazolium trimellitate, 2,4-diamino-6- [2'-methylimidazolyl- (1 ')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino- 6- [2′-Methylimidazolyl- (1 ′)]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl- 4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo [1,2-a] benzimidazole, 1-dodecyl-2-methyl Examples include imidazole compounds such as -3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins, such as 2-ethyl-4-methylimidazole and 1-benzyl-2- Phenylimidazole is preferred.

  Commercially available products may be used as the imidazole curing accelerator, and examples thereof include “P200-H50” manufactured by Mitsubishi Chemical Corporation.

  Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1 -Allyl biguanide, 1-phenyl biguanide, 1- ( - tolyl) biguanide, and the like, dicyandiamide, 1,5,7-triazabicyclo [4.4.0] dec-5-ene are preferred.

  As a metal type hardening accelerator, the organometallic complex or organometallic salt of metals, such as cobalt, copper, zinc, iron, nickel, manganese, tin, is mentioned, for example. Specific examples of the organometallic complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. Organic zinc complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

  Although content of the hardening accelerator in a resin composition is not specifically limited, 0.01 mass%-3 mass% are preferable when the non-volatile component total amount of a thermosetting resin and a hardening | curing agent is 100 mass%.

<(G) Thermoplastic resin>
Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples include ether ketone resins and polyester resins, among which thermoplastic resins having an aromatic structure are preferable, for example, phenoxy resins having an aromatic structure, polyvinyl acetal resins having an aromatic structure, polyimide resins having an aromatic structure, Polyamideimide resin having aromatic structure, polyetherimide resin having aromatic structure, polysulfone resin having aromatic structure, polyethersulfone resin having aromatic structure, aromatic Polyphenylene ether resin having a forming, polyether ether ketone resin having an aromatic structure, preferably a polyester resin having an aromatic structure, phenoxy resins having an aromatic structure is preferable. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

  The weight average molecular weight in terms of polystyrene of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and still more preferably in the range of 20,000 to 60,000. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, the polystyrene-reduced weight average molecular weight of the thermoplastic resin is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K- manufactured by Showa Denko KK as a column. 804L / K-804L can be calculated using a standard polystyrene calibration curve by measuring the column temperature at 40 ° C. using chloroform or the like as a mobile phase.

  Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene Examples thereof include phenoxy resins having a skeleton and one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. Specific examples of the phenoxy resin include “1256” and “4250” (both bisphenol A skeleton-containing phenoxy resin), “YX8100” (bisphenol S skeleton-containing phenoxy resin), and “YX6954” (manufactured by Mitsubishi Chemical Corporation). In addition, "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., "YX6954BH30", "YX7553", "YX7553BH30" manufactured by Mitsubishi Chemical Corporation, “YL7769BH30”, “YL6794”, “YL7213”, “YL7290”, “YL7482” and the like.

  Examples of the polyvinyl acetal resin include a polyvinyl formal resin and a polyvinyl butyral resin, and a polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include, for example, “Electrical butyral 4000-2”, “Electrical butyral 5000-A”, “Electrical butyral 6000-C”, and “Electrical butyral 6000-EP” manufactured by Denki Kagaku Kogyo Co., Ltd. , Sreck BH series, BX series (for example, BX-5Z), KS series (for example, KS-1), BL series, and BM series manufactured by Sekisui Chemical Co., Ltd.

  Specific examples of the polyimide resin include “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Specific examples of the polyimide resin include linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimide described in JP-A-2006-37083), a polysiloxane skeleton. Examples thereof include modified polyimides such as containing polyimide (polyimides described in JP-A Nos. 2002-12667 and 2000-319386).

  Specific examples of the polyamide-imide resin include “Bilomax HR11NN” and “Bilomax HR16NN” manufactured by Toyobo Co., Ltd. Specific examples of the polyamideimide resin also include modified polyamideimides such as “KS9100” and “KS9300” (polysiloxane skeleton-containing polyamideimide) manufactured by Hitachi Chemical Co., Ltd.

  Specific examples of the polyethersulfone resin include “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

  Specific examples of the polysulfone resin include polysulfone “P1700” and “P3500” manufactured by Solvay Advanced Polymers Co., Ltd.

  Of these, phenoxy resin and polyvinyl acetal resin are preferable as the thermoplastic resin. Accordingly, in a preferred embodiment, the thermoplastic resin includes one or more selected from the group consisting of a phenoxy resin and a polyvinyl acetal resin.

  When the resin composition contains a thermoplastic resin, the content of the thermoplastic resin is preferably 0.5% by mass to 60% by mass, more preferably 3% by mass to 50% by mass, and even more preferably 5% by mass to 40% by mass.

<(H) Flame retardant>
Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. A flame retardant may be used individually by 1 type, or may use 2 or more types together.

  Commercially available products may be used as the flame retardant, and examples thereof include “HCA-HQ” manufactured by Sanko Co., Ltd.

  When the resin composition contains a flame retardant, the content of the flame retardant is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and still more preferably. 0.5 mass%-10 mass% are further more preferable.

<Other ingredients>
The resin composition may further contain other additives as necessary. Examples of such other additives include organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds, And resin additives such as thickeners, antifoaming agents, leveling agents, adhesion-imparting agents, and coloring agents.

(Sheet fiber substrate)
The sheet-like fiber base material used for the prepreg of this invention is not specifically limited, What is used normally as base materials for prepregs, such as a glass cloth, an aramid nonwoven fabric, and a liquid crystal polymer nonwoven fabric, can be used.

Specific examples of the glass cloth that can be used as the sheet-like fiber base material include “Style 1027MS” manufactured by Asahi Schwer Corporation (warp density 75/25 mm, weft density 75/25 mm, fabric weight 20 g / m ² , (Thickness 19 μm), “Style 1037MS” manufactured by Asahi Schavel Co., Ltd. (warp density 70/25 mm, weft density 73/25 mm, fabric weight 24 g / m ² , thickness 28 μm), manufactured by Arisawa Manufacturing Co., Ltd. “1078” (warp density 54/25 mm, weft density 54/25 mm, fabric weight 48 g / m ² , thickness 43 μm), “1037NS” manufactured by Arizawa Seisakusho (warp density 72/25 mm, weft density 69 pieces / 25 mm, fabric weight 23 g / m ² , thickness 21 μm), “1027NS” manufactured by Arisawa Manufacturing Co., Ltd. (warp density 75 pieces / 25 mm, weft density 75 Book / 25 mm, cloth weight 19.5 g / m ² , thickness 16 μm), “1015NS” manufactured by Arisawa Manufacturing Co., Ltd. (warp density 95/25 mm, weft density 95/25 mm, cloth weight 17.5 g / m ² , 15 μm thick), “1000NS” manufactured by Arisawa Manufacturing Co., Ltd. (warp density 85/25 mm, weft density 85/25 mm, fabric weight 11 g / m ² , thickness 10 μm), and the like. Specific examples of the liquid crystal polymer non-woven fabric include “Veculus” (weight per unit area 6 g / m ^{2 to} 15 g / m ² ) and “Vectran” manufactured by Kuraray Co., Ltd. by the melt blow method of aromatic polyester non-woven fabric.

  The thickness of the prepreg is preferably 50 μm or less, more preferably 40 μm or less, still more preferably 30 μm or less, and even more preferably 20 μm or less from the viewpoint of reducing the thickness of the printed wiring board.

  The prepreg of the present invention may be laminated with a protective film or a metal foil as necessary.

  Examples of the protective film include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter sometimes abbreviated as “PEN”), polycarbonate (hereinafter referred to as “PC”). And acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide and the like. Moreover, you may use a support body with a release layer as a protective film. Examples of the release agent used for the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, a commercially available product may be used. For example, “SK-1” manufactured by Lintec Corporation, which is a PET film having a release layer mainly composed of an alkyd resin release agent. , “AL-5”, “AL-7”, “Lumirror T6AM” manufactured by Toray Industries, Inc., and the like.

  The metal foil includes one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The metal foil may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel chromium alloy, copper nickel alloy) And a layer formed from a copper / titanium alloy). Above all, from the viewpoint of versatility of forming metal foil, cost, easiness of patterning, etc., single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel chromium alloy, copper nickel Alloy, copper titanium alloy alloy layer is preferable, chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper single metal layer, or nickel chromium alloy alloy layer is more preferable, copper single metal layer is Further preferred. The metal foil may be a laminate of a plurality of metal foils.

[Prepreg production method]
The prepreg of the present invention can be produced by a known method such as a hot melt method or a solvent method. In the hot melt method, the resin composition and the release paper having good releasability are once coated without dissolving the resin composition in an organic solvent, and then laminated on a sheet-like fiber substrate, or formed into a sheet by a die coater. The prepreg is manufactured by coating directly on the fiber base material. In the solvent method, the sheet-like fiber base material is immersed in a varnish obtained by dissolving the resin composition in an organic solvent to impregnate the sheet-like fiber base material, and then dried to produce a prepreg. Yes. Furthermore, the prepreg can also be produced by sandwiching a sheet-like fiber base material from both sides thereof with two resin sheets made of a resin composition and continuously heat-laminating under heating and pressure conditions.

  Moreover, the manufacturing method of a prepreg may be performed by a roll-to-roll system using a long sheet-like fiber base material, and may be performed by a batch system.

  The prepreg of the present invention exhibits the characteristic that the occurrence of warpage is suppressed. The magnitude of the warp is preferably less than 1.5 cm, more preferably 1.3 cm or less or -1 cm or less, more preferably 0 cm. The warpage can be measured according to the method described in <Evaluation of warpage> described later.

  The prepreg of the present invention exhibits good handling properties. In one embodiment, even if the prepreg is peeled after the prepreg is once stacked on the substrate, there is no deposit such as resin on the substrate. The handling property can be measured according to the method described in <Evaluation of handling property> described later.

  The prepreg of the present invention exhibits good embedding properties. In one embodiment, when laminating on a substrate with a wiring layer, a prepreg can be laminated on the wiring layer without voids. The embeddability can be measured according to the method described in <Evaluation of pattern embeddability> in Examples described later.

  The prepreg of the present invention exhibits good copper peel strength (copper plating peel strength). In one embodiment, it is preferably 1.5 kgf / cm or less, more preferably 1.3 kgf / cm or less, and still more preferably 1.0 kgf / cm or less. Although there is no restriction | limiting in particular about a minimum, it is 0.4 kgf / cm or more. The copper peeling strength can be measured according to the method described in <Measurement of copper peeling strength (copper plating peel strength)> in Examples described later.

[Printed wiring board and manufacturing method thereof]
The printed wiring board of the present invention can be produced by a method including the following steps (I) and (II) using the above prepreg.
(I) The process of laminating | stacking so that a prepreg may join to an inner layer board | substrate on an inner layer board | substrate (II) The process of thermosetting a prepreg and forming an insulating layer

  The “inner layer substrate” used in step (I) is mainly a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or one or both surfaces of the substrate. A circuit board on which a patterned conductor layer (circuit) is formed. Further, when the printed wiring board is manufactured, an inner layer circuit board of an intermediate product in which an insulating layer and / or a conductor layer is further formed is also included in the “inner layer board” in the present invention. When the printed wiring board is a component built-in circuit board, an inner layer board with built-in components may be used.

  Lamination of the inner layer substrate and the prepreg can be performed, for example, by thermocompression bonding the prepreg to the inner layer substrate. Examples of the member that heat-presses the prepreg to the inner layer substrate (hereinafter, also referred to as “heat-pressing member”) include a heated metal plate (SUS end plate, etc.) or a metal roll (SUS roll). It is preferable that the thermocompression bonding member is not pressed directly onto the prepreg, but is pressed through an elastic material such as heat-resistant rubber so that the prepreg sufficiently follows the surface unevenness of the inner layer substrate.

  Lamination of the inner layer substrate and the prepreg may be performed by a vacuum laminating method. In the vacuum laminating method, the thermocompression bonding temperature is preferably in the range of 60 ° C to 160 ° C, more preferably 80 ° C to 140 ° C, and the thermocompression bonding pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0. The thermocompression bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably performed under reduced pressure conditions with a pressure of 26.7 hPa or less.

  Lamination can be performed with a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho, a vacuum applicator manufactured by Nichigo Morton, and the like.

  After the lamination, the laminated prepreg may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression bonding member from the support side. The pressing conditions for the smoothing treatment can be the same conditions as the thermocompression bonding conditions for the laminate. The smoothing treatment can be performed with a commercially available laminator. In addition, you may perform lamination | stacking and a smoothing process continuously using said commercially available vacuum laminator.

  In step (II), the prepreg is thermally cured to form an insulating layer.

  The conditions for thermosetting the prepreg are not particularly limited, and the conditions normally employed when forming the insulating layer of the printed wiring board may be used.

  For example, the thermosetting conditions of the prepreg vary depending on the type of the resin composition, but the curing temperature is in the range of 120 ° C to 240 ° C (preferably in the range of 150 ° C to 220 ° C, more preferably in the range of 170 ° C to 200 ° C. Range), curing time can be in the range of 5 minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

  Prior to thermosetting the prepreg, the prepreg may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the prepreg, the prepreg is kept at a temperature of 50 ° C. or more and less than 120 ° C. (preferably 60 ° C. or more and 110 ° C. or less, more preferably 70 ° C. or more and 100 ° C. or less) for 5 minutes or more (preferably (5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes).

  When manufacturing a printed wiring board, you may further implement (III) the process of drilling in an insulating layer, (IV) the process of roughening an insulating layer, and (V) the process of forming a conductor layer. These steps (III) to (V) may be carried out according to various methods known to those skilled in the art, which are used in the production of printed wiring boards.

  Step (III) is a step of making a hole in the insulating layer, whereby holes such as via holes and through holes can be formed in the insulating layer. Step (III) may be performed using, for example, a drill, laser, plasma, or the like, depending on the composition of the resin composition used for forming the insulating layer. The dimensions and shape of the holes may be appropriately determined according to the design of the printed wiring board.

  Step (IV) is a step of roughening the insulating layer. The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming an insulating layer of a printed wiring board can be employed. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralization treatment with a neutralizing liquid in this order. Although it does not specifically limit as a swelling liquid, An alkaline solution, surfactant solution, etc. are mentioned, Preferably it is an alkaline solution, As this alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include “Swelling Dip Securigans P” and “Swelling Dip Securigans SBU” manufactured by Atotech Japan Co., Ltd. Although the swelling process by a swelling liquid is not specifically limited, For example, it can perform by immersing an insulating layer for 1 minute-20 minutes in 30 degreeC-90 degreeC swelling liquid. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the cured body in a swelling liquid at 40 ° C. to 80 ° C. for 5 minutes to 15 minutes. Although it does not specifically limit as an oxidizing agent, For example, the alkaline permanganate solution which melt | dissolved potassium permanganate and sodium permanganate in the aqueous solution of sodium hydroxide is mentioned. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60 to 80 ° C. for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as “Concentrate Compact CP” and “Dosing Solution Securigans P” manufactured by Atotech Japan Co., Ltd. The neutralizing solution is preferably an acidic aqueous solution. Examples of commercially available products include “Reduction Solution Securigant P” manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in the neutralizing solution at 30 to 80 ° C. for 5 to 30 minutes. From the viewpoint of workability and the like, a method of immersing an object subjected to roughening treatment with an oxidizing agent in a neutralizing solution at 40 ° C. to 70 ° C. for 5 minutes to 20 minutes is preferable.

  In one embodiment, the arithmetic average roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 400 nm or less, more preferably 350 nm or less, further preferably 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less. It is. The arithmetic average roughness (Ra) of the insulating layer surface can be measured using a non-contact type surface roughness meter. As a specific example of the non-contact type surface roughness meter, “WYKO NT3300” manufactured by Becoins Instruments is cited.

  Step (V) is a step of forming a conductor layer.

  The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer is one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper- A layer formed from a nickel alloy and a copper / titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel / chromium alloy, copper / An alloy layer of nickel alloy or copper / titanium alloy is preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel / chromium alloy is more preferable, and a single layer of copper is preferable. A metal layer is more preferred.

  The conductor layer may have a single layer structure or a multilayer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc or titanium, or an alloy layer of nickel / chromium alloy.

  Although the thickness of a conductor layer is based on the design of a desired printed wiring board, generally it is 3 micrometers-35 micrometers, Preferably it is 5 micrometers-30 micrometers.

  In one embodiment, the conductor layer may be formed by plating. For example, the surface of the insulating layer can be plated by a conventionally known technique such as a semi-additive method or a full additive method to form a conductor layer having a desired wiring pattern. Hereinafter, an example in which the conductor layer is formed by a semi-additive method will be described.

  First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern that exposes a part of the plating seed layer corresponding to a desired wiring pattern is formed on the formed plating seed layer. A metal layer is formed by electrolytic plating on the exposed plating seed layer, and then the mask pattern is removed. Thereafter, an unnecessary plating seed layer can be removed by etching or the like to form a conductor layer having a desired wiring pattern.

The printed wiring board of this invention may be an aspect provided with the insulating layer which is the hardened | cured material of the prepreg of this invention, and the embedding type wiring layer embedded in the insulating layer.
As a manufacturing method of such a printed wiring board,
(1) preparing a substrate with a wiring layer having an inner layer substrate and a wiring layer provided on at least one surface of the substrate;
(2) A step of laminating the prepreg of the present invention on a substrate with a wiring layer so that the wiring layer is embedded in the prepreg and thermally curing to form an insulating layer;
(3) a step of interconnecting the wiring layers, and (4) a step of removing the base material.

  It is preferable to have a metal layer made of copper foil or the like on both surfaces of the inner layer substrate used in this manufacturing method, and it is more preferable that the metal layer has a structure in which two or more metal layers are laminated. For the details of the step (1), a dry film (photosensitive resist film) is laminated on the inner layer substrate, and exposed and developed under a predetermined condition using a photomask to form a pattern dry film. A wiring layer is formed by electroplating using the developed pattern dry film as a plating mask, and then the pattern dry film is peeled off.

  The lamination conditions of the inner layer substrate and the dry film are the same as the conditions of the step (II) described above, and the preferred range is also the same.

  After laminating the dry film on the inner layer substrate, exposure and development are performed under predetermined conditions using a photomask in order to form a desired pattern on the dry film.

  The line (circuit width) / space (inter-circuit width) ratio of the wiring layer is not particularly limited, but is preferably 20/20 μm or less (that is, the pitch is 40 μm or less), more preferably 18/18 μm or less (pitch 36 μm or less), More preferably, it is 15/15 μm or less (pitch 30 μm or less). The lower limit of the line / space ratio of the wiring layer is not particularly limited, but is preferably 0.5 / 0.5 μm or more, more preferably 1/1 μm or more. The pitch need not be the same throughout the wiring layer.

  After forming the dry film pattern, a wiring layer is formed, and the dry film is peeled off. Here, the wiring layer can be formed by a plating method using a dry film having a desired pattern as a plating mask.

  The conductor material used for the wiring layer is not particularly limited. In a preferred embodiment, the wiring layer is one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. Contains metal. The wiring layer may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper- A nickel alloy and a copper / titanium alloy).

  The thickness of the wiring layer depends on the design of the desired printed wiring board, but is preferably 3 μm to 35 μm, more preferably 5 μm to 30 μm, and even more preferably 10 to 20 μm, or 15 μm.

  After forming the wiring layer, the dry film is peeled off. Peeling of the dry film can be performed by a known method. If necessary, an unnecessary wiring pattern can be removed by etching or the like to form a desired wiring pattern.

  Step (2) is a step in which the insulating layer is formed by laminating the prepreg of the present invention on a substrate with a wiring layer so that the wiring layer is embedded in the prepreg and thermosetting the prepreg. The lamination conditions of the substrate with a wiring layer and the prepreg are the same as those in the above-described step (II), and the preferred range is also the same.

  The step (3) is not particularly limited as long as the wiring layers can be connected to each other, but a step of forming a via hole in the insulating layer to form a conductor layer, and a step of polishing or grinding the insulating layer to expose the wiring layer It is preferable that it is at least one of these steps. The process of forming the via hole in the insulating layer and forming the conductor layer is as described above.

  The insulating layer polishing method or grinding method is not particularly limited as long as the printed wiring layer can be exposed and the polishing or grinding surface is horizontal, and conventionally known polishing methods or grinding methods can be applied, Examples thereof include a chemical mechanical polishing method using a chemical mechanical polishing apparatus, a mechanical polishing method such as buffing, and a surface grinding method by rotating a grinding wheel.

  Step (4) is a step of removing the inner substrate and forming the printed wiring board of the present invention. The method for removing the inner layer substrate is not particularly limited. In a preferred embodiment, the inner substrate is peeled from the printed wiring board at the interface of the metal layer on the inner substrate, and the metal layer is etched away with, for example, an aqueous copper chloride solution.

[Semiconductor device]
A semiconductor device of the present invention includes the printed wiring board of the present invention. The semiconductor device of the present invention can be manufactured using the printed wiring board of the present invention.

  Examples of the semiconductor device include various semiconductor devices used for electrical products (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircrafts).

  The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. The “conduction location” is a “location where an electrical signal is transmitted on a printed wiring board”, and the location may be a surface or an embedded location. The semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

  The semiconductor chip mounting method for manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip functions effectively, but specifically, a wire bonding mounting method, a flip chip mounting method, and no bumps. Examples include a mounting method using a build-up layer (BBUL), a mounting method using an anisotropic conductive film (ACF), and a mounting method using a non-conductive film (NCF). Here, “a mounting method using a build-up layer without a bump (BBUL)” means “a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board and the semiconductor chip and wiring on the printed wiring board are connected”. It is.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the following description, “parts” and “%” mean “parts by mass” and “% by mass”, respectively, unless otherwise specified.

  First, measurement methods and evaluation methods in physical property evaluation will be described.

[Preparation of measurement and evaluation substrate]
(1) Production of inner layer circuit board IPC MULTI- on glass cloth base epoxy resin double-sided copper-clad laminate (copper foil thickness 35 μm, board thickness 0.8 mm, Matsushita Electric Works “R5715ES”) PURPOSE TEST BOARD NO. An IPC C-25 pattern (line / space ratio = 600/660 μm comb tooth pattern (residual copper ratio 48%)) was formed. Subsequently, the both surfaces of the substrate were roughened with a microetching agent (“CZ8100” manufactured by MEC Co., Ltd.) to produce an inner layer circuit board.

(2) Lamination of prepreg The prepreg produced in the following examples and comparative examples and a copper foil with a carrier ("MT-Ex" manufactured by Mitsui Mining & Smelting Co., Ltd., copper foil thickness: 3 μm) so that the copper foil is on the outside are described above. The laminate was placed above and below the inner circuit board and pressed at a temperature of 190 ° C. for 90 minutes at a pressure of 20 kgf / cm ² to obtain a laminate.

[Evaluation]
<Evaluation of pattern embedding>
After peeling the carrier copper from the laminate obtained in the above (2), the remaining copper was immersed in an iron chloride solution to peel the copper, and the surface 3 cm ^{2 of the} insulating layer was made into a microscope (manufactured by KEYENCE CORPORATION). Microscope VK-8510 ") was observed, and a case where there was no wrinkle or void was indicated as" O ", and a case where there was a wrinkle or void was indicated as" X ".

<Measurement of copper peel strength (copper plating peel strength)>
After peeling carrier copper from the laminate obtained in (2) above, electrolytic copper plating was performed to form a conductor layer (copper layer) having a total thickness of 30 μm. A notch surrounding a partial region of 10 mm in width and 100 mm in length was made in the obtained substrate with a conductor layer, and one end side was peeled off to grasp the grip (TSE, Inc., Autocom type tester AC- 50C-SL), and the load (kgf / cm (N / cm)) when 35 mm was peeled off in the vertical direction at a speed of 50 mm / min at room temperature (25 ° C.) was measured. The case where the peel strength was 0.4 kgf / cm or more was “◯”, and the case where the peel strength was less than 0.4 kgf / cm was “x”.

<Evaluation of warpage>
The prepregs produced in the following examples and comparative examples are placed on one side of a copper foil (“JTC foil” manufactured by JX Nippon Mining & Metals Co., Ltd., copper foil thickness: 70 μm), at a pressure of 20 kgf / cm, at a temperature of 190 ° C. An evaluation sample was obtained by pressing for 90 minutes. Of the four sides of the obtained prepreg-attached copper foil, two sides were fixed to a SUS plate with a polyimide tape, and the height of the highest point was obtained from the SUS plate to obtain the value of warpage. And when the magnitude of the warp is 0 cm or more and less than 1.5 cm, “◯”, −1 cm or more and less than 0 cm, or 1.5 cm or more and less than 3 cm is “Δ”, less than −1 cm, or 3.5 cm or more. × ”. In addition, about the magnitude | size of curvature, the case where it bent to the prepreg side when arrange | positioning a prepreg upward was set to "+", and the case where it bent to the copper foil side was set to "-".

<Evaluation of prepreg handling>
The prepreg produced in the following example was peeled after overlapping the substrate obtained in (1) above at atmospheric pressure, and the surface 3 cm ² was peeled off using a microscope (“Microscope VK-8510” manufactured by KEYENCE Corporation). The case where there was no resin adhesion on the substrate was indicated as “◯”, and the case where there was resin adhesion on the substrate was indicated as “x”.

<Measurement of average maximum length of domain>
For the average maximum length of the domain, a FIB-SEM composite device (“SMI3050SE” manufactured by SII Nanotechnology Co., Ltd.) was used. A cross section in a direction perpendicular to the surface of the prepreg thermally cured at 100 ° C. for 30 minutes and then at 170 ° C. for 30 minutes was cut out by FIB (focused ion beam), and a cross-sectional SEM image (observation width 60 μm, observation magnification 2) 1,000 times). Randomly selected cross-sectional SEM images at five locations were observed, the largest domain existing in the cross-sectional SEM image was selected, the maximum length of each selected domain was measured, and the average value was taken as the average maximum length.

[Example 1]
28 parts of a butadiene elastomer produced as follows, 5 parts of a dicyclopentadiene type epoxy resin (“HP-7200L” manufactured by DIC Corporation, epoxy equivalent 245), and a bisphenol type epoxy resin (Nippon Steel Chemical Co., Ltd.) ) “ZX1059”, 1: 1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy equivalent of about 169) 3 parts was dissolved in 15 parts of methyl ethyl ketone (MEK) with stirring. There, 1 part of a curing accelerator (1B2PZ manufactured by Shikoku Kasei Co., Ltd., 1-benzyl-2-phenylimidazole, MEK solution containing 5% by mass of non-volatile components) and organic particles (manufactured by Aika Industry Co., Ltd., Staphyloid AC3816N) ) And 1 part of spherical silica ("SOC4" manufactured by Admattex Co., Ltd.) having a surface treatment with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) as an inorganic filler, an average particle size of 1. (0 μm) 11 parts were mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish 1.

<Preparation of prepreg>
Resin varnish 1 was impregnated into Nitto Boseki Co. Style WEA2013 (warp density 46/25 mm, weft density 44/25 mm, fabric mass 81 g / m ² , thickness 71 μm) and 135 in a vertical drying furnace. A prepreg was prepared by drying at 5 ° C. for 5 minutes. The resin composition content in the prepreg was 48% by mass, and the thickness of the prepreg was 90 μm. The length of the prepreg in the vertical direction was 30 cm, and the length in the horizontal direction was 20 cm.

<Synthesis of butadiene elastomer>
In a reaction vessel, 50 g of G-3000 (bifunctional hydroxyl group-terminated polybutadiene, number average molecular weight = 5047 (GPC method), hydroxyl group equivalent = 1798 g / eq., Solid content: 100 mass%: Nippon Soda Co., Ltd.) 23.5 g of ipsol 150 (aromatic hydrocarbon-based mixed solvent: manufactured by Idemitsu Petrochemical Co., Ltd.) and 0.005 g of dibutyltin laurate were mixed and dissolved uniformly. When the temperature became uniform, the temperature was raised to 50 ° C., and while further stirring, 4.8 g of toluene-2,4-diisocyanate (isocyanate group equivalent = 87.08 g / eq.) Was added and the reaction was carried out for about 3 hours. The reaction was then cooled to room temperature before 8.96 g benzophenonetetracarboxylic dianhydride (acid anhydride equivalent = 161.1 g / eq.), 0.07 g triethylenediamine, and ethyl diglycol. 40.4 g of acetate (manufactured by Daicel Chemical Industries, Ltd.) was added, the temperature was raised to 130 ° C. with stirring, and the reaction was carried out for about 4 hours. The disappearance of the NCO peak at 2250 cm ⁻¹ was confirmed by FT-IR. The confirmation of the disappearance of the NCO peak was regarded as the end point of the reaction, and the reaction product was cooled to room temperature and then filtered through a 100 mesh filter cloth to obtain a butadiene elastomer.
Properties of butadiene elastomer:
Viscosity: 7.5 Pa · s (25 ° C, E-type viscometer)
Acid value: 16.9 mgKOH / g
Solid content: 50% by mass
Number average molecular weight: 13723
Content of polybutadiene structure part: 50 × 100 / (50 + 4.8 + 8.96) = 78.4% by mass.

[Example 2]
Instead of 11 parts of spherical silica ("SOC4" manufactured by Admattex Co., Ltd., average particle size 1.0 µm), rhombus boehmite ("BMB-05" manufactured by Kawai Lime Industry Co., Ltd., average particle size 0.5 µm) 15 Resin varnish 2 and prepreg 2 were produced in the same manner as in Example 1 except that the parts were used.

[Example 3]
Epoxy group-containing acrylic ester copolymer (“SG-P3” manufactured by Nagase ChemteX Corp., number average molecular weight Mn: 850000 g / mol, epoxy value 0.21 eq / kg) and 55 parts of bisphenol type epoxy resin (new "ZX1059" manufactured by Nippon Steel Chemical Co., Ltd., 1 part of 1: 1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy equivalent of about 169), and bisphenol novolac type epoxy resin (Mitsubishi Chemical Corporation) “157S70” manufactured by Epoxy Co., Ltd. and 3.5 parts were heated and dissolved with stirring. Thereto, 4 parts of a triazine skeleton-containing cresol novolac-based curing agent (“LA3018-50P” manufactured by DIC Corporation, hydroxyl group equivalent 151, 1-methoxy-2-propanol solution containing 50% nonvolatile components) and a curing accelerator (Shikoku) 1 part 2B2PZ, 1-benzyl-2-phenylimidazole manufactured by Kasei Co., Ltd., 0.1 part of MEK solution containing 5% by mass of non-volatile components, and 0.8 part of organic particles (Aka Kogyo Co., Ltd., Staphyloid AC3816N), As an inorganic filler, 10 parts of rhombus boehmite (“BMB-05” manufactured by Kawai Lime Industry Co., Ltd., average particle size 0.5 μm) were mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish 3. . A prepreg 3 was produced in the same manner as in Example 1 except that the resin varnish 3 was used instead of the resin varnish 1.

[Example 4]
Resin varnish 4 and prepreg 4 were prepared in the same manner as in Example 1 except that the addition amount of spherical silica (“SOC4” manufactured by Admattex Co., Ltd., average particle size 1.0 μm) was changed to 40 parts.

[Example 5]
Addition amount of butadiene elastomer is 10 parts, addition amount of spherical silica (“SOC4” manufactured by Admattex Co., Ltd., average particle size 1.0 μm) is 7 parts, and organic particles (manufactured by Aika Industry Co., Ltd., Staphyloid AC3816N) Resin varnish 5 and prepreg 5 were prepared in the same manner as in Example 1 except that the amount of addition was changed to 0.6 part.

[Example 6]
5 parts of the butadiene elastomer produced as described above, 9 parts of a dicyclopentadiene type epoxy resin (“HP-7200L” manufactured by DIC Corporation, epoxy equivalent 245), and a bisphenol type epoxy resin (Nippon Steel Chemical Co., Ltd.) ) "ZX1059", 1: 1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy equivalent of about 169) 4 parts were dissolved in 15 parts of methyl ethyl ketone (MEK) with stirring. There, 1 part of hardening accelerator (1B2PZ manufactured by Shikoku Kasei Co., Ltd., MEK solution containing 5% by mass of non-volatile components), 1 part of organic particles (manufactured by Aika Kogyo Co., Ltd., Staphyloid AC3816N), and inorganic filler 10 parts of spherical silica (“SOC4” manufactured by Admattex Co., Ltd., average particle size 1.0 μm) surface-treated with a phenylaminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) is mixed. The resin varnish 6 was produced by uniformly dispersing with a high-speed rotary mixer. A prepreg 6 was produced in the same manner as in Example 1 except that the resin varnish 6 was used instead of the resin varnish 1.

[Example 7]
Resin varnish 7 and prepreg 7 were prepared in the same manner as in Example 1 except that the amount of butadiene-based elastomer added was changed to 40 parts.

[Example 8]
Resin varnish 8 and prepreg 8 were produced in the same manner as in Example 1 except that the addition amount of spherical silica (“SOC4” manufactured by Admattex Co., Ltd., average particle size 1.0 μm) was changed to 5 parts.

[Example 9]
Resin varnish 9 and prepreg 9 were prepared in the same manner as in Example 1 except that the addition amount of spherical silica (“SOC4” manufactured by Admattex Co., Ltd., average particle size 1.0 μm) was changed to 60 parts.

[Comparative Example 1]
28 parts of butadiene elastomer produced as described above, bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel Chemical Co., Ltd.), 1: 1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, epoxy Equivalent about 169) 2.5 parts and 5 parts of bisphenol novolac type epoxy resin (“157S70”, epoxy equivalent 210 made by Mitsubishi Chemical Corporation) were dissolved in 15 parts of methyl ethyl ketone (MEK) with stirring. There, 1 part of a curing accelerator (1B2PZ manufactured by Shikoku Kasei Co., Ltd., 1-benzyl-2-phenylimidazole, MEK solution containing 5% by mass of non-volatile components) and organic particles (manufactured by Aika Industry Co., Ltd., Staphyloid AC3816N) ) And 1 part of spherical silica ("SOC4" manufactured by Admattex Co., Ltd.) having a surface treatment with a phenylaminosilane coupling agent ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd.) as an inorganic filler, an average particle size of 1. (0 μm) and 11 parts were mixed and dispersed uniformly with a high-speed rotary mixer to prepare a resin varnish 10. A prepreg 10 was produced in the same manner as in Example 1 except that the resin varnish 10 was used instead of the resin varnish 1.

[Comparative Example 2]
Resin varnish 11 and prepreg 11 were prepared in the same manner as in Example 1 except that the amount of organic particles (Aka Kogyo Co., Ltd., Staphyloid AC3816N) added was changed to 4 parts.

[Comparative Example 3]
Resin varnish 12 and prepreg 12 were prepared in the same manner as in Example 1 except that the butadiene elastomer was not added.

  From the table, it can be seen that the prepregs of Examples 1 to 9 are improved in handling property, embedding property, and copper plating peel strength, and are not warped. In addition, Comparative Examples 1 and 2 in which the average maximum length of the domain exceeds 15 μm, and Comparative Example 3 not including the component (a) are examples of handling property, embedding property, copper plating peel strength, and warpage. It turns out that it is inferior to the prepreg of 1-9. In the measurement of the copper plating peel strength of Comparative Example 1, the copper plating peel strength could not be measured because a part of the copper foil swelled and the copper foil peeled off after heating the prepreg.

  Further, as shown in FIG. 1, in Example 1, the average maximum length of the domain was 7.2 μm. As shown in FIG. 2, Example 2 is so small that the average maximum length of the domain cannot be confirmed, and it can be seen that each component such as an inorganic filler is dispersed. On the other hand, as shown in FIG. 3, in Comparative Example 1, since the average maximum length of the domain is 18.0 μm, it is considered that the embedding property and the copper plating peel strength are inferior to those of Examples 1-9. .

  In Example 6 and Example 7, since (A / (A + B)) × 100 is outside the range of 20 to 70, (A / (A + B)) × 100 is within the range of 20 to 70. Although the warpage was inferior to the examples, there was no actual damage in use.

  In Examples 8 and 9, since the content of the inorganic filler is outside the range of 25 to 70% by mass, the content of the inorganic filler is within the range of 25 to 70% by mass. Although the warpage was inferior to that, there was no practical harm in use.

Claims (14)

A sheet-like fiber base material, and a resin composition impregnated in the sheet-like fiber base material,
The resin composition contains (a) an elastomer, (b) a thermosetting resin having an aromatic structure, and (c) an inorganic filler,
A prepreg having an average maximum domain length of 15 μm or less, which is contained in a cured product obtained by thermosetting a resin composition.   The prepreg according to claim 1, wherein the resin composition comprises (d) organic particles.   The component (a) is at least one selected from resins having a functional group capable of reacting with the component (b) and having a glass transition temperature of 25 ° C or lower or a liquid state at 25 ° C. The prepreg described in 1.   The component (a) is a butadiene structural unit, a polysiloxane structural unit, a (meth) acrylate structural unit, an alkylene structural unit, an alkyleneoxy structural unit, an isoprene structural unit, an isobutylene structural unit, a chloroprene structural unit, a urethane structural unit, or a polycarbonate structural unit. The prepreg according to any one of claims 1 to 3, which has one or more structural units selected from the group consisting of:   (B) The prepreg of any one of Claims 1-4 which contains a solid epoxy resin at the temperature of 20 degreeC as a component.   As a component (b), an epoxy resin that is liquid at a temperature of 20 ° C. and an epoxy resin that is a solid at a temperature of 20 ° C., and the mass ratio of the liquid epoxy resin to the solid epoxy resin is 1: 0.3 to 1:10. The prepreg according to any one of claims 1 to 5, wherein   The prepreg according to claim 5 or 6, which does not contain a resin having a molecular weight of 400 or more having a naphthalene skeleton as a solid epoxy resin at a temperature of 20 ° C.   Any one of Claims 1-7 whose (A / (A + B)) * 100 is 20-70, when the mass of the (a) component in a resin composition is A and the mass of the (b) component is B. The prepreg according to item 1.   The prepreg according to any one of claims 1 to 8, wherein the content of the component (c) is 25 to 70% by mass when the nonvolatile component in the resin composition is 100% by mass.   When the mass of the component (a) in the resin composition is A, the mass of the component (b) is B, and the mass of the component (d) is D, (D / (A + B + D)) × 100 is 10 or less. The prepreg according to any one of claims 2 to 9.   The prepreg according to any one of claims 1 to 10, which is used for forming an insulating layer of a printed wiring board.   The prepreg according to any one of claims 1 to 11, which is used for forming a buildup layer of a printed wiring board.   The printed wiring board containing the insulating layer formed with the prepreg of any one of Claims 1-12.   A semiconductor device comprising the printed wiring board according to claim 13.