Process for etching a semiconductor lead frame
US5683943A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1995 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Jun 12, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49121
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for producing a lead frame having outer leads and inner leads, for use in constructing a resin-sealed semiconductor package comprises etching processes for etching a blank. A first resist pattern having a first opening and a second resist pattern having second openings are formed on the first and the second major surfaces of a blank. The first and the second major surfaces of the blank are etched through the first and the second resist pattern by a first etching process using a first etchant to form a first recess corresponding to the first opening and second recesses corresponding to the second recesses in the first and the second major surfaces, respectively. The first recess is filled up with an etch-resistant layer. The second major surface is etched through the second resist pattern by a second etching process using a second etchant so that portions of the blank corresponding to the second openings of the second resist pattern are etched through to form the tips of the inner leads.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.