Photo-or heat-curable resin composition and multilayer printed wiring board

摘要

This invention relates to a photo- or heat-curable resin composition which yields a cured product with minimal cracking and high reliability. The resin composition of this invention comprises 100 parts by weight of the resin-forming component containing a photo- or heat-polymerizable unsaturated compound and 0.01-5 parts by weight of an inorganic filler such as silica sol with its average particle diameter controlled in the range 5 nm-0.5 mum. The composition exhibits high heat resistance and good microfabrication quality and is useful as a peripheral material of electronic parts such as semiconductor devices by the build-up process, for example, as a material for forming insulation layers in multilayer printed wiring boards.