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:
May. 18, 2004
Filed:
Dec. 03, 2002
Applicant:
Inventors:
Toshihiko Taguchi, Saitama, JP;
Kunihito Takaura, Mouka, JP;
Masahiko Hirata, Kashiba, JP;
Hisahiko Yoshida, Ibaraki, JP;
Takashi Nagashima, Kyoto, JP;
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K 3/5363 ; B23K 3/5365 ;
U.S. Cl.
CPC ...
B23K 3/5363 ; B23K 3/5365 ;
Abstract
A lead-free solder paste comprises an Sn—Zn based lead-free solder powder mixed with a flux. The flux contains at least one aromatic hydroxycarboxylic acid selected from the group consisting of aromatic carboxylic acids having one hydroxyl group in a meta position (such as 3-hydroxy-2-methylbenzoic acid) and aromatic carboxylic acids having at least two hydroxyl groups (such as dihydroxynaphthoic acid or dihydroxybenzoic acid) in an amount of 0.1-10.0 mass %. The flux may further include 0.5-20 mass % of an aliphatic hydroxy carboxylic acid (such as hydroxyoleic acid).