Patent ID: 7416695

Claim:
A method of manufacturing a semiconducting polyimide film, comprising: a conductivity imparting step of adding a semiconducting inorganic filler to a polyamide acid solution which is a solution of an organic solvent containing polyamide acid; a gel film mold step of, following the conductivity imparting step, partially hardening and/or partially drying the polyamide acid to mold a gel film; and a post-conductivity-imparting imidization step of imidizing the polyamide acid contained in the gel film, wherein the semiconducting inorganic filler has a volume resistivity (powder resistance) of 10 5 to 10 9 Ωcm, and the semiconducting inorganic filler is acicular and a shorter axis of the semiconducting inorganic filler falls within a range between 0.01 μm and 1 μm, while a longer axis of the semiconducting inorganic filler falls within a range between 1 μm and 20 μm, and the polyamide acid is made of at least one kind of diamine selected from 4,4′ diaminodiphenylpropane, 4,4′-diaminodiphenylmethane, benzidine, 3,3′-dichorobenzidine, 4,4′-diaminodiphenylsulfide, 3,3′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylether, 3,3′-diaminodiphenylether, 3,4′-diaminodiphenylether, 1,5-diaminonaphthalene, 4,4′-diaminodiphenyldiethylsilane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethyl phosphine oxide, 4,4′-diaminodiphenyl N-methylamine, 4,4′-diaminodiphenyl N-phenylamine, 1,4-diaminobenzene(p-phenylene diamine), and 1,2-diaminobenzene, and the imidization is performed at a heat treatment temperature range of 450° C. to 550° C. in the post-conductivity-imparting imidization step.