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US 5,344,747 AGranted
Photopolymerizable compositions
AssigneeTokyo Ohka Kogyo Co., Ltd.
InventorsShigeru Ohtawa, Junichi Onodera, Kouji Harada
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Abstract
A photopolymerizable composition composed principally of an acrylic linear copolymer, an ethylenically-unsaturated compound and a photoinitiator and adapted to fabricate printed circuit boards. The ethylenically-unsaturated compound contains a specific acrylic ester. The photopolymerizable composition can be developed with an aqueous mild alkaline solution.
Claims7
A method of forming a pattern, comprising
- (a) dissolving or dispersing in an organic solvent a photopolymerizable composition consisting essentially of (i) a linear acrylic copolymer having a weight average molecular weight of 30,000 to 200,000 and a glass transition point of 20.degree.-80.degree. C., (ii) an ethylenically-unsaturated component comprising 10-50 wt. %, based on the total amount of the ethylenically-unsaturated component, of an acrylic ester of the formula CH.sub.2 =C(X)-COO-Y-OCO-Z-COOH, wherein X is selected from the group of hydrogen and methyl, Y is (C.sub.1 -C.sub.3)alkylene, and Z is selected from the group consisting of a single bond, (C.sub.1 -C.sub.8) alkylene, phenylene, and cyclohexylene, and (iii) a photoinitiator, the weight ratio of the ethylenically-unsaturated component to the acrylic copolymer being 0.1:1 to 1:1;
- (b) coating a substrate directly with the resulting solution;
- (c) drying the coated substrate to form a resist film;
- (d) exposing the dried resist film imagewise to radiation;
- and
- (e) developing the resist film with an aqueous alkaline solution.
3 more elements
Dependencies are inferred from the claim text.