Laser beam scanning method for forming via holes in polymer materials
US4894115A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1989 |
| Grant date | Jan 16, 1990 |
| Priority date | — |
| Expiry date | Feb 14, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/095
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The surface of a polymer dielectric layer is scanned repeatedly with a high energy continuous wave laser in a pattern to create via holes of desired size, shape and depth. This is followed by a short plasma etch. The via holes are produced at commercial production rates under direct computer control without use of masks and without damage to conductor material underlying the dielectric layer. A two-step technique usable to form a large hole to a partial depth in the dielectric layer and several smaller diameter holes within the large hole through the remainder of the dielectric layer depth allows formation of a large number of holes in a given area of a thick dielectric layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.