Wire bonding to dual metal covered pad surfaces
US6759597B1 · kind B1 · utility
30Cited by
3References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 2, 1998 |
| Grant date | Jul 6, 2004 |
| Priority date | — |
| Expiry date | Oct 27, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49151
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Wire bonds are made to palladium coated bonded pads on organic dielectric substrates at temperatures below 200° C. A layer of palladium thicker than 14 micro-inches is covered with a thin flash of gold. Palladium coated over copper pads is protected from copper diffusion by a thin nickel layer positioned between the two. Subsequent baking for 1 hour at 185° C. drives off hydrogen molecules provided the gold is less than 200 å thick. A bonding wire, preferably of gold is then successfully bonded to the pad using conventional bonding equipment at temperatures below 200° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.