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:
Feb. 27, 1979
Filed:
Jan. 30, 1978
William P Dugan, Pomona, CA (US);
Eugene Phillips, Diamond Bar, CA (US);
General Dynamics Corporation, Pomona, CA (US);
Abstract
Carriers forming strips for semiconductor integrated circuit chips. The carrier consists basically of a flexible tape, such as a polyimide. A conductive sheet, such as a copper sheet, is initially prepared to form a lead circuit on one surface and a bump circuit on the other. This metal sheet may be gold plated. Subsequently, a layer of polyimide is applied to the lead circuit side and both the polyimide sheet and the opposite bump circuit are covered with a metal sheet, such as copper. A photoresist layer is put over the copper and is suitably illuminated and developed to provide apertures through which the copper can be etched to expose the polyimide sheet. This takes place over the windows or openings adjacent the bumps for the application of a heat ram as well as for the sprocket holes used for precisely aligning the carrier with the to-be-associated semiconductor chips. Finally, openings may also be provided to separate adjacent carrier strips from each other. The exposed polyimide layer is now removed by chemical milling. Subsequently the previously applied outer copper sheets are removed as by etching.