Method of forming solder mask
US5368884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1993 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Sep 9, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/1355
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention has as its object providing a solder mask which permits high density mounting, is suitable for protecting conductor circuits, particularly has mask thickness on the circuit parts and each edge part of the circuits which make almost no difference from those on other parts, and is excellent in electrical insulation, heat resistance and solvent resistance. This invention provides a method of forming a solder mask for printed circuit boards, using any powder paint which is curable by both irradiation of ultraviolet ray and heat, comprising: PA1 (1) a step of coating the powder paint on a printed circuit board, while holding it at a temperature higher than a softening point of the powder paint, PA1 (2) a step of irradiating ultraviolet rays thereon through a pattern mask, PA1 (3) a step of making development with a medium which dissolves the region not irradiated by ultraviolet rays and, PA1 (4) a step of completely curing the coating part developed on the printed circuit board at a temperature higher than the curing temperature of the powder paint.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.