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:
Sep. 16, 2003
Filed:
Oct. 23, 2002
Yoshikazu Nakata, Shiga, JP;
Takeshi Kasai, Yamaguchi, JP;
Sumitomo Metal (SMI) Electronics Devices Inc., Yamaguchi, JP;
Abstract
In a chip package, when a Ni/Au layer is formed by electroless plating, there is no problem with density increasing of interconnections and the like, since leads for plating and tie bars are not formed. However, the adhesive strength of solder balls to ball pads is low, so that the adhesion tends to be unstable. In the present invention, no leads for plating are formed, while the adhesive strength of solder balls to ball pads is improved by electroplating the ball pads with a Ni/Au layer. In addition, an increase in the density of interconnections and an improvement of the electrical properties is also obtained. The Ni/Au layer is formed by electroplating on the base metal layer surface which is not covered with a DFR (Dry Film Resist) by applying an electric current to the base metal layer.