Laser processed coatings on electronic circuit substrates
US5391841A · kind A · utility
Inventor
Key dates
| Filing date | Dec 8, 1992 |
| Grant date | Feb 21, 1995 |
| Priority date | — |
| Expiry date | Dec 8, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Enhanced thermal and electrical properties of ceramic for high-power integrating substrates are provided by focused thermal energy sources such as by laser processing. A thin ceramic layer, such as alumina, is plasma spray deposited on a relative thick metal substrate, such as copper or alloy thereof, as a heat sink for improved dielectric and thermal properties which are produced by laser-reflow and recrystallization so as to convert and provide a different ceramic of higher dielectric and denser structure. Laser-reflow and recrystallization causes a purification or purging and conversion process that vaporizes deleterious impurities and changes the crystalline structure while densifying the resulting structure of the ceramic layer. After conversion of the ceramic layer a metal coating may be plasma spray deposited thereon and electrical circuit elements and wiring patterns may be formed thereon by laser etching for high power applications, such as heat-sinks, electronic control modules, or heating panels. As another aspect, ceramic coated metal substrates with recesses or cavities formed therein contiguous with its surfaces, may be laser-reflow processed for containing microelect…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.