Test coupons for determining the registration of subsurface layers in a multilayer printed circuit board
US4510446A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1982 |
| Grant date | Apr 9, 1985 |
| Priority date | — |
| Expiry date | Nov 3, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2201/09781
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present disclosure describes test coupons having predetermined respective test patterns, formed in a multilayer printed circuit board simultaneously with the fabrication of the latter. The test coupons are probed with conventional electrical instruments to provide information as to the occurrence of a misregistration of any given subsurface printed plane or trace, whether or not the misregistration exceeds a specified limit, and if desired, a measure of the degree of misregistration. The foregoing are readily accomplished in a time and cost efficient manner without the need for cross-sectioning portions of the board and the visual observation of the subsurface printed layers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.