Solder-coated printed circuit board and method of manufacturing the same
US5296649A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 17, 1992 |
| Grant date | Mar 22, 1994 |
| Priority date | — |
| Expiry date | Mar 17, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A plurality of pads are formed on a circuit board body at a pitch of 0.5 mm or less. The pads are formed such that a projecting height H of a pad from the board body surface and a width W of the pad satisfy a relation 2H<W, that a pad array is formed in which a width of each of the pads located at two ends of the pad array is larger than that of a pad located therebetween, and that the pad width W and a pad-to-pad distance D satisfy a relation W>D. A solder layer, obtained by a substitution reaction between a powder of a metal having the highest ionization tendency among metals constituting the solder layer or a powder of an alloy thereof and a salt formed by bonding the other metal or metals in the solder layer to an organic acid, is formed on each pad.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.