Resin composition, prepreg and metal-foil-clad laminate

Abstract

A resin composition excellent in heat resistance after moisture absorption, lead-free solder reflow properties, dimensional stability and electrical characteristics for high-multilayer and high-frequency-capable printed wiring boards, which composition comprises a bisphenol A type epoxy resin (a) having at least two epoxy groups per molecule and a secondary hydroxyl group amount of 0.4 meq/g or less, a novolak type epoxy resin (b) at least two epoxy groups per molecule, a cyanate ester resin (c) having at least two cyanate groups per molecule and spherical silica having an average particle diameter of 4 μm or less, wherein the equivalent ratio of cyanate groups/epoxy groups in the resin composition is in the range of 0.7 to 1.45, and a prepreg and a metal-foil-clad laminate each of which comprises the resin composition.

Description

Claims

1. A resin composition comprising a bisphenol A type epoxy resin (a) having at least two epoxy groups per molecule and having a secondary hydroxyl group amount of 0.4 meq/g or less, a novolak type epoxy resin (b) having at least two epoxy groups per molecule, a cyanate ester resin (c) having at least two cyanate groups per molecule and spherical silica having an average particle diameter of 4 μm or less, wherein the equivalent ratio of cyanate groups/epoxy groups in the resin composition is in the range of 0.7 to 1.45.

2. The resin composition according to claim 1, wherein the bisphenol A type epoxy resin (a) is a brominated bisphenol A type epoxy resin.

3. The resin composition according to claim 1, wherein the content of the spherical silica in the resin composition is 10 to 70 parts by weight per 100 parts by weight of a resin solid content in the resin composition.

4. A prepreg obtained by impregnating or applying the resin composition as defined in claim 1 into/to a glass woven fabric.

5. A metal-foil-clad laminate obtained by placing one prepreg as defined in claim 4 or stacking at least two prepregs as defined in claim 4, then disposing metal foil(s) on one surface or both surfaces of the prepreg or the resultant stack of the prepregs, and laminate-molding the resultant set.