System and method for solder ball rework
US6574861B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 11, 2001 |
| Grant date | Jun 10, 2003 |
| Priority date | — |
| Expiry date | Sep 8, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49165
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A system and method have been provided for removing high lead content solder balls from the surface of a circuit package for the purpose of rework. The invention is applicable to ball grid array (BGA), C4 balls, chip scale balls, and flip chip bumps. Advantageously, the room temperature solder ball rework procedure minimizes damage to the circuit package. Specifically, a thin-film stainless steel mask with openings to expose the solder balls, is formed over the circuit package, and the solder balls are removed in a shearing or grinding operation, leaving a solder ball residue. Then, a conventional thick mask film is formed and a solder paste is deposited to fill the apertures. The solder ball residue forms a wettable surface for the low temperature attachment of new solder balls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.