Lead frame
US10811346B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2020 |
| Grant date | Oct 20, 2020 |
| Priority date | — |
| Expiry date | Mar 20, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/181
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A lead frame includes a lead frame substrate made of a copper-based material, plating layers composed of nickel, palladium and gold layers laminated in this order on top faces and bottom faces of the lead frame substrate, and a roughened silver plating layer having acicular projections, provided as an outermost plating layer and covering faces of the lead frame substrate that form concavities or a through hole between the top faces and the bottom faces of the lead frame substrate. The roughened silver plating layer has a crystal structure in which the crystal direction <101> occupies a largest proportion among the crystal directions <001>, <111> and <101>. The lead frame can be manufactured with improved productivity owing to reduction in cost and operation time, and achieves remarkably high adhesion to sealing resin while keeping the total thickness of plating layers including the silver plating layer to be thin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.