Via formation method for multilayer interconnect board
US5108785A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1989 |
| Grant date | Apr 28, 1992 |
| Priority date | — |
| Expiry date | Sep 15, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K3/4667
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method of boring holes in a circuit board assembly of the type having a first layer of material which is primarily reflective of light of a first light wavelength and having a second layer of material, overlying the first layer of material, which is primarily absorptive of light of the first light wavelength, comprising: tuning the frequency of a laser cutting device to the first light wavelength; directing a laser beam from the tuned laser cutting device onto the second layer of material in a region where a hole is to be provided; and terminating application of the laser beam after a hole has been bored through the second layer of material.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.