Solder-on back metal for semiconductor die
US6376910B1 · kind B1 · utility
11Cited by
7References
19Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 23, 1999 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Jun 23, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/1576
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A solderable back contact for semiconductor die consists of a titanium layer bonded to the bottom of the die. The free surface of the titanium layer is coated with a copper layer. A soft solder layer joins the bottom of the die to a copper lead frame by first heating the die to below the melting point of the solder, and then ultrasonically “scrubbing” the solder to cause it to bond to the die and lead frame with a minimum sized solder fillet.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.