Patent ID: 7687590
Filing Date: 2010-03-30
Classification: C09D,H01L,Y10T

Abstract:
1. A composition for forming silica based coating film comprising component (a): siloxane resin, component (b): a solvent capable of dissolving said component (a), and component (c): an onium salt, wherein said component (a) comprises at least one specific bonded atom selected from the group consisting of H, F, B, N, Al, P, Si, Ge, Ti and C atoms, the specific bonded atom being bonded to Si atom forming siloxane bonds of the siloxane resin, and a total number (M) calculated using the relationship represented by the following formula (6) is 0.20 or greater and no more than 0.50: where M1 represents a total number of atoms of said at least one specific bonded atom bonded to a single Si atom forming siloxane bonds of the siloxane resin, M2 represents a total number of atoms of said at least one specific bonded atom shared by two Si atoms forming siloxane bonds of the siloxane resin, M3 represents a total number of atoms of said at least one specific bonded atom shared by three Si atoms forming siloxane bonds of the siloxane resin, and Msi represents a total number of Si atoms forming siloxane bonds of the siloxane resin, wherein said component (a) is obtained by hydrolytic condensation promoted by an organic acid or an inorganic acid, wherein the composition for forming silica based coating film has curing properties such that the stress of said silica based coating film obtained by heating at 150° C. for 3 minutes is 10 MPa or greater, and the specific permittivity of the silica based coating film obtained by final curing is less than 3.0.