Semiconductor device having increased moisture path and increased solder joint strength
US6525406B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 13, 2000 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Oct 13, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/18301
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Disclosed is a semiconductor package and a method for manufacturing the same. A planar or substantially planar die pad is disposed within a leadframe and is connected to the leadframe by a plurality of tie bars. An perimeter of an upper and lower surface of the die pad is half-etched to increase the moisture-permeation path of the finished package. A plurality of rectangular leads extends from the leadframe toward the die pad without contacting the die pad. A silver-plating layer may be formed on the upper surface of the leadframe. A semiconductor chip is mounted on the upper surface of the die pad in the leadframe. After deflashing, the package is treated with a sulfuric (H2SO4)-based solution to restore the internal leads to their original color. Prior to singulation, the externally exposed bottom surfaces of the leads are plated with copper, gold, solder, tin, nickel, palladium, or an alloy thereof to form a predetermined thickness of a plating layer. The singulation step comprises forming a burr at a peripheral side surface of the leads in the upward direction. The finished package may be marked with a recognition mark to enable a user to more easily identify the first lead.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.