Process for the production of printed circuit boards with extremely dense wiring using a metal-clad laminate
US5436062A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1994 |
| Grant date | Jul 25, 1995 |
| Priority date | — |
| Expiry date | Feb 14, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24917
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a metal-clad laminate the requirements concerning the mechanical strength are functionally separated from the circuit connection requirement, so as to be able to bring the circuit connection, particularly for signals, "closer" to the electrotechnical characteristics of the chips. For this purpose and without taking account of the mechanical strength of the substrate, the layout miniaturization is optimized. In place of a circuit board (MCM), a laminate which can be built up to a circuit board is produced. The inventive laminate comprises an extremely thin foil with a plurality of extremely small holes simultaneously etched in an etching process. The hole diameter can be reduced by almost an order of magnitude (up to 20 .mu.m), which permits a sub-100 .mu.m technology. Such a laminate is not used as a mechanical support and is only provided for signal guidance. The effect of the miniaturization can be seen in the diameter for the plated-through holes. With a hole diameter reduction there is an increase in the current path density, which gives over 10000 plated-through holes per dm.sup.2. A drawing shows the compression ratio compared with standard technology.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.