Film carrier having tin and indium plated layers
US4935312A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1988 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Dec 9, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12708
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Film carriers for mounting electronic components such as semiconductor chips thereon have lead portions plated with a tin or tin alloy layer and further with an indium layer. The tin or tin alloy layer is 0.1-3 .mu.m thick and the indium layer 0.01-2 .mu.m thick. Alternatively, the leads have a tin or tin alloy plated portion having an indium diffusion layer, with an indium content of 0.2-50 wt %. The carriers are manufactured by a method which comprises plating the leads with tin or a tin alloy and then with indium, with or without heat treatment at 50.degree.-150.degree. C. to form an indium diffusion layer in the tin or tin alloy coating. Plating is done by electroless plating.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.