Chisso Corporation

Masami Wada

Shiro Konotsune

Hiromi Higashi

Hiroshi Maehara

Kazuyuki Tsuji

Haruo Kato

Masamitsu Okamoto

Hideaki Shouji

Hidenori Funikawa

A process for producing a cheap carrier tape of a two layer structure having a superior heat resistance, difficultly susceptible of effect of impurities and having a superior flexibility is provided, which process comprising the following steps: coating a polyimide varnish onto a continuous, electrically-conductive metal foil and baking it; punching the resulting tape of a two layer structure of the metal foil and the polyimide film to form sprocket holes; cutting and removing the polyimide film to form a device hole; coating a resist onto the metal foil surface; light-exposing the resulting resist by the medium of a mask for separating a circuit pattern and a circuit from the sprocket parts; developing the resulting resist and etching the metal foil by the medium of a mask of the resist; removing the resist; and plating the metal foil.

Process for producing a carrier tape

A silicon-containing step ladder polymer comprising a unit represented by the following general formula (I): ##STR1## a unit represented by the following general formula (II): ##STR2## and a unit represented by the following general formula (III): ##STR3## where R.sup.1 represents a hydrocarbon or fluorine-substituted hydrocarbon group, R.sup.2 represents hydrogen or a trialkyl siloxy group, and R.sup.3 and R.sup.4 which may be identical or different with each other represent individually hydrocarbon or fluorine-substituted hydrocarbon groups, the molar ratio of the unit (I) to the unit (II) is between 5:1-100:1 and the molar ratio of the unit (III) to the total amount of the unit (I)+unit (II) is between 1:5-1:100, as well as a process for producing such polymer.

Silicon-containing step ladder polymer and a process for producing the

Growing community of inventors

Yokosukashi, Japan

Masami Wada