Etching method for forming a lead frame
US5481798A · kind A · utility
18Cited by
4References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 13, 1995 |
| Grant date | Jan 9, 1996 |
| Priority date | — |
| Expiry date | Jan 13, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49222
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A lead frame capable of easily connecting an inner lead to an electrode of a semiconductor element by way of a bump of the inner lead, and a method of manufacturing the lead frame capable of significantly easily forming the bump. A bump forming metal layer is formed on a metal base sheet on an area where each inner lead is to be formed. The inner lead is formed on the bump forming metal layer, and the bump forming metal layer is etched using the inner lead as a mask, thus forming a bump. After that, each outer lead is formed by selective etching of the metal base sheet from the rear surface side.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.