Lead-free solder, and paste solder composition
US6726780B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 2003 |
| Grant date | Apr 27, 2004 |
| Priority date | — |
| Expiry date | Mar 10, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3485
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is provided a lead-free solder which makes it possible to reliably and accurately perform the inspection of various kinds of defective soldering in the inspection using an image inspection apparatus after the reflow soldering. According to this lead-free solder, the delustering of the metallic luster of fillet is realized in order to minimize the probability of generating a dark portion at the area where no defective soldering is existed and instead to increase the area of whitish portion which can be generated through the irregular reflection of beam. Specifically, this invention provides a lead-free solder comprising an Sn—Ag—Cu-based lead-free solder containing a small quantity of Bi and Sb as an element which is capable of generating a delustering component for minimizing metallic luster of the fillet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.