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:
Jul. 01, 1997
Filed:
Oct. 24, 1995
Masayuki Ochiai, Kawasaki, JP;
Hidefumi Ueda, Kawasaki, JP;
Michio Sono, Kawasaki, JP;
Ichiro Yamaguchi, Kawasaki, JP;
Kazuhiko Mitobe, Kawasaki, JP;
Koki Otake, Kawasaki, JP;
Junichi Kasai, Kawasaki, JP;
Nobuo Kamehara, Kawasaki, JP;
Yasuo Yamagishi, Kawasaki, JP;
Masataka Mizukoshi, Kawasaki, JP;
Yutaka Yamada, Kawasaki, JP;
Susumu Abe, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A method for fabricating a semiconductor device using a solder ball forming plate having cavities. The plate is made from a silicon plate having a flat surface in a <110> crystallographic plane, and an orientation flat in a <1-11> crystallographic plane. The cavities are formed on the flat surface of the plate by etching, using a mask having openings in the shape of rhombus arranged such that one side of the rhombus is generally parallel to the <1-11> crystallographic plane. As a result, the cavities having wedge-shaped bottom are formed. The cavities are then filled with a solder paste and are heated to form solder balls in the cavities while the plate in an inclined position. The solder balls are then transferred from the plate to a semiconductor chip.