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. 19, 2002
Filed:
Mar. 09, 2000
Hitoshi Aoki, Yokohama, JP;
Takeshi Hosomi, Yokohama, JP;
Kensuke Nakamura, Yokohama, JP;
Hideki Hara, Akita, JP;
Masaaki Kato, Yokosuka, JP;
Sumitomo Bakelite Company Limited, Tokyo, JP;
Abstract
The invention relates to a low-cost transfer bump sheet which is capable of transferring copper-cored solder bumps with high reliability of bonding to a semiconductor chip and which is capable of transferring bumps of various structures. The invention also relates to a low-cost semiconductor flip chip in which copper-cored solder bumps with high reliability of bonding are mounted on a semiconductor chip through the use of the transfer bump sheet. In the transfer bump sheet, metal posts of two or more layers are formed on a base sheet. The invention also relates to a method of manufacturing this semiconductor flip chip, which comprises the steps of forming the base sheet on a metal foil, forming a plating mask on the metal foil, forming a first solder layer (solder coating) on the metal foil by electrolytic plating or electroless plating, removing the plating mask, and forming a metal layer (metal core) of metal posts by the etching of the metal foil through the use of the formed first solder layer (solder coating) as an etching mask.