Providing selective via plating using laser resin activation
US8528203B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 7, 2011 |
| Grant date | Sep 10, 2013 |
| Priority date | — |
| Expiry date | Nov 4, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T156/1057
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An enhanced mechanism for via stub elimination in printed wiring boards (PWBs) and other substrates employs laser resin activation to provide selective via plating. In one embodiment, the resin used in insulator layers of the PWB contains spinel-based non-conductive metal oxide. Preferably, only insulator layers through which vias will pass contain the metal oxide. Those layers are registered and laser irradiated at via formation locations to break down the metal oxide and release metal nuclei. Once these layers are irradiated, all layers of the PWB or subcomposite are laid up and laminated. The resulting composite or subcomposite is subsequently drilled through and subjected to conventional PWB fabrication processes prior to electroless copper plating and subsequent copper electroplating. Because metal nuclei were released only in the via formation locations of the appropriate layers, plating occurs in the via barrels only along those layers and partially plated vias are created without stubs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.