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:
Mar. 22, 1994
Filed:
Mar. 17, 1992
Izumi Kosuga, Tokyo, JP;
Kenichi Fuse, Tokyo, JP;
Takao Fukunaga, Tokyo, JP;
Hirokazu Shiroishi, Tokyo, JP;
Masanao Kohno, Kakogawa, JP;
Hisao Irie, Takasago, JP;
The Furukawa Electric Co., Ltd., Tokyo, JP;
Harima Chemicals, Inc., Hyogo, JP;
Abstract
A plurality of pads are formed on a circuit board body at a pitch of 0.5 mm or less. The pads are formed such that a projecting height H of a pad from the board body surface and a width W of the pad satisfy a relation 2H<W, that a pad array is formed in which a width of each of the pads located at two ends of the pad array is larger than that of a pad located therebetween, and that the pad width W and a pad-to-pad distance D satisfy a relation W>D. A solder layer, obtained by a substitution reaction between a powder of a metal having the highest ionization tendency among metals constituting the solder layer or a powder of an alloy thereof and a salt formed by bonding the other metal or metals in the solder layer to an organic acid, is formed on each pad.