Method and tooling for z-axis offset of lead frames
US6928850B2 · kind B2 · utility
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15References
10Claims
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Key dates
| Filing date | Apr 19, 2004 |
| Grant date | Aug 16, 2005 |
| Priority date | — |
| Expiry date | Apr 19, 2024 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49218
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for enabling z-axis offset of narrow metal ties straps in lead frames used for packaging integrated circuits to prevent bowing or distortion. Simultaneous offsetting of the tie strap and stress relief mechanisms are provided on both the front and back sides of the lead frame. Those mechanisms include indentations along the long or primary axis of each tie strap, coupled with depressions across the top surface both at the center of the lead frame and between the base of the off set and the chip attach locations to prevent bowing in small pad and no pad lead frames, in particular.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.