LOW DIELECTRIC ADHESIVE COMPOSITION

摘要

Provided is an adhesive composition that is highly adhesive not only to conventional polyimide and polyester films but also to low polarity resin base materials such as LCP and metal base materials, ensures a high solder heat resistance and has excellent low dielectric properties and good pot life properties. The adhesive composition contains a solvent-soluble resin and satisfies the following requirements (1)-(4): (1) the dielectric constant (εc) at 1 MHz frequency of a cured product of the adhesive composition being 3.0 or less; (2) the dielectric tangent (tanδ) at 1 MHz frequency of the cured product of the adhesive composition being 0.02 or less; (3) the 90° peel strength of a laminate consisting of a liquid crystal polymer film and a copper foil, said polymer film and foil being bonded to each other with the adhesive composition, being 0.5 N/mm or more; and (4) the solution viscosity ratio (solution viscosity ηB/solution viscosity ηB0) of a toluene solution of the solvent-soluble resin (solid concentration 20 mass%) being 0.5 or more and less than 3.0 [wherein solution viscosity ηB0 stands for the solution viscosity at 25°C immediately after dissolving the solvent-soluble resin in toluene, and solution viscosity ηB stands for the solution viscosity at 25°C after dissolving the solvent-soluble resin in toluene and then allowing the obtained solution to stand for 7 days at 5°C].