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AssigneeSony Chemicals Corp.
InventorsSatoshi Takahashi, Akira Tsutsumi, Koichi Uno, Minoru Nagashima
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Photoresist compositions, which can attain high-accuracy etching without causing separation and flexible printed wiring boards prepared with the photoresist compositions are disclosed. In order to etch a polyimide precursor layer on a conductive circuit, a photoresist composition comprising a photopolymerizable organic material (A), a water-soluble resin (B) and an amino-group-containing resin (C) is applied on the surface of the polyimide precursor layer to form a photoresist layer. Then, the photoresist layer is patterned by a photolithographic process. The polyimide precursor layer is etched and the pattern of the photoresist layer is transferred to the polyimide precursor layer. The amino-group-containing resin (C) in the photoresist layer is combined with an acid anhydride in the polyimide precursor layer to attain good adhesion and high-accuracy etching without causing separation of the photoresist layer. Alternatively, a film can be formed from the photoresist composition and then be applied on the surface of the polyimide precursor layer to form a photoresist layer.
A method of making a flexible printed wiring board comprising a conductive circuit and a patterned polyimide layer on the conductive circuit, comprising:
Dependencies are inferred from the claim text.