Process for via fill
US5927193A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 16, 1997 |
| Grant date | Jul 27, 1999 |
| Priority date | — |
| Expiry date | Oct 16, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/082
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus and method is provided for vacuum screen printing a greensheet having vias and both vias and open areas whereby vacuum leakage in the apparatus is minimized and avoids bowing of the screen over the open area of the greensheet. An interposer apparatus is provided comprising at least two layers having vertical through openings in registration with the via openings of the greensheet and screen. The interposer also comprises vertical through openings communicating with the open area of the greensheet and with vent channels of the interposer. A porous membrane is also used either alone or in conjunction with the interposer to provide enhanced screening results.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.