Bump forming method, presoldering treatment method, soldering method, bump forming apparatus, presoldering treatment device and soldering apparatus
US6742701B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | May 30, 2002 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | May 30, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/3494
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Process gas is fed from a gas supply means to a plasma generating means in a vacuum chamber, and hydrogen-containing plasma is generated by the plasma generating means under a low pressure. A soft solder alloy on the surface of a workpiece supported by a workpiece exposing means is exposed to the hydrogen-containing plasma so that the soft solder alloy is irradiated with the hydrogen-containing plasma. Either simultaneously with or immediately after the plasma irradiation, the soft solder alloy undergoes reflow treatment in a vacuum by a heating means. As no flux is used, there is no need of a washing process, and the bump-shaped electrode terminals produced by using the inexpensive soft solder alloy on the surface of the workpiece have great reliability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.