Leadframe for integrated circuit package
US5889317A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 6, 1997 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Jun 6, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/181
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A leadframe for an IC package and a method of manufacturing the same are provided. The leadframe can be manufactured in such a manner as to provide suitable bondability, molding compound characteristic, and solderability. The leadframe includes a base structure made from a conductive material. A silver plating is formed over the base structure of the leadframe, and a palladium plating is formed over the silver plating. Depending on actual requirements, a copper layer and a nickel plating can be formed between the silver plating and the base structure of the leadframe, and a palladium/nickel plating can be found between the silver and palladium platings. Further, a gold layer can be formed over the palladium plating. The palladium plating and the palladium/nickel plating can be formed all over the leadframe or selectively formed only in the external-lead area of the leadframe. The structure of the layering of one silver layer beneath the palladium plating allows the prevention of the occurrence of pin holes in the platings so that the bondability and solderability of the leadframe can be assured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.