Surface treated structure for solder joint
US5635764A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 9, 1994 |
| Grant date | Jun 3, 1997 |
| Priority date | — |
| Expiry date | Aug 9, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/181
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
On a rear surface of a semiconductor (10), a contact layer (11), a diffusion preventing layer (12) and a solder joint layer (13) are formed, and this solder joint layer (13) is connected to a mount base (15) by a Pb-Sn solder layer (14). The contact layer (11) is formed of a rare earth metal, its silicide or a composite thereof, the diffusion preventing layer (12) is formed of a ferrous metal, and the solder joint layer (13) is formed of a Ni-Au alloy. By forming the diffusion preventing layer (12) using the ferrous metal, a diffusion of tin in a solder is prevented and by the solder joint layer (13) of the Ni-Au alloy, an excellent solder joint property can be maintained to reduce the number of laminated layers. Further, as a surface treated layer of at least one joint member, the Ni-Au alloy is used and by heating the semiconductor substrate via a solder foil in a reducing atmosphere a high airtightness is obtained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.