METHOD FOR FORMING PROTECTIVE FILM ON ELECTRONIC DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a mullilayered film which can be used for hermetic protection and can enhance protection of an electronic device against illegal probing, inspection or invasion. SOLUTION: Hydrogenated silses quioxane resin (H resin) is first applied to a surface of an electronic device, and then the resin is heated to be converted to a ceramic layer containing silica. Then a silicon carbide film is formed on the first film by a chemical vapor deposition(CVD) process. Next, a third ceramic layer containing impermeable or opaque porous silica is formed on the silicon carbide film, the H resin is applied thereto and then heated to be converted to ceramic containing porous silica. Impregnated into the third layer containing porous silica is impermeable material or material containing a filling agent. A fourth layer is made of metal or alloy. Next, The fourth layer is covered with substantially the same fifth layer as the third ceramic layer containing opaque porous silica. However, the composition of the fifth opaque layer is preferably different from that of the third opaque layer.