Wiring board and method of producing the same
US6998336B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 3, 2005 |
| Grant date | Feb 14, 2006 |
| Priority date | — |
| Expiry date | Mar 3, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/043
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of producing a wiring board includes a preliminary plating step of forming a solder resist layer such that the main layer of each metal pad of the board is exposed in each corresponding opening and covering the surface of the exposed main layer with a preliminary Sn plated layer. A solder paste application step involves applying a solder paste, containing solder powder comprised of the high temperature Sn solder and thicker than the preliminary Sn plated layer, on the preliminary Sn plated layer. A subsequent solder melting step involves forming the Sn solder covering layer by melting the solder paste layer together with the preliminary Sn plated layer by heating the solder paste layer to a temperature higher than the liquid phase line temperature of the high temperature Sn solder. This wettingly extends the melted layers over the surface of the main layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.