The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 12, 1989
Filed:
Aug. 19, 1987
Applicant:
Inventors:
Hiroshi Watanabe, Mito, JP;
Osamu Miura, Hitachi, JP;
Kunio Miyazaki, Hitachi, JP;
Shunichi Numata, Hitachi, JP;
Kanji Otsuka, Higashiyamato, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ;
U.S. Cl.
CPC ...
156643 ; 1566591 ; 1566611 ; 156668 ; 437203 ; 437944 ;
Abstract
In a process for forming a wiring conductor of Cu, Al, Au or the like on a wiring substrate, polyimide-based resin having the following unit structural formula is used as a lift-off material. ##STR1## wherein R.sub.1 : ##STR2## R.sub.2 : ##STR3## n is an integer of 15,000 to 30,000. This lift-off material has very good etching susceptibility and can be selectively lifted off with an etching solution of a mixture of hydrazine and ethylene diamine from a lower polyimide layer having R.sub.1 : ##STR4## R.sub.2 : ##STR5## .