Lead-free solder ball
US7750475B2 · kind B2 · utility
5Cited by
8References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Oct 6, 2004 |
| Grant date | Jul 6, 2010 |
| Priority date | — |
| Expiry date | Oct 6, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3463
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A Sn—Ag—Cu based lead-free solder ball which does not undergo yellowing of its surface when formed into a solder bump on an electrode of an electronic part such as a BGA package. The solder ball has excellent wettability and does not form voids at the time of soldering, even when it has a minute diameter such as 0.04-0.5 mm. It has a composition comprising 1.0-4.0 mass % of Ag, 0.05-2.0 mass % of Cu, 0.0005-0.005 mass % of P, and a remainder of Sn.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.