Preventing conductive anodic filament (CAF) formation by sealing discontinuities in glass fiber bundles
US8974888B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2011 |
| Grant date | Mar 10, 2015 |
| Priority date | — |
| Expiry date | Nov 9, 2032 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24322
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An enhanced substrate for making a printed circuit board (PCB) includes a silane applied to the ends of glass fibers in via holes. In one embodiment, during a plated through-hole (PTH) via fabrication process, glass fiber bundles exposed in a drilled through-hole are selectively sealed. For example, after the through-hole is drilled in a substrate, the substrate may be subjected to an aqueous silane bath (e.g., an organo trialkoxysilane in an aqueous solution of an acid that acts as a catalyst) to deposit a layer of silane on the exposed glass fiber bundle ends. For example, trialkoxy groups of the silane may react with exposed silanols on the glass to form a siloxane, which is further polymerized to form a silane polymer barrier layer on the exposed glass fiber ends. The barrier layer effectively seals the glass fiber bundles and eliminates the conductive anodic filament (CAF) pathway between PTH vias.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.