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:
Nov. 23, 1993
Filed:
Sep. 26, 1991
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
437180 ; 437195 ; 437978 ; 437194 ; 257210 ; 257211 ; 257758 ; 257760 ;
Abstract
A method of automatic wiring in a semiconductor integrated circuit device having four or more wiring layers, with the lowest layer being a terminal layer, is intended to overcome the prior art problem in which lower layers are mostly used for wiring and upper layers are not used efficiently. The method is designed to assign longer lines to upper layers distant from the terminal layer, and upper layers can have increased wiring densities with minimal numbers of lines, bends and through holes, thereby using upper layers efficiently.