Wiring substrate features having controlled sidewall profiles
US6548224B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 2000 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Mar 7, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/056
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A dielectric layer in a wiring substrate having a sloped sidewall. A photomask used to pattern the dielectric layer includes optical proximity features. The size and spacing of the optical proximity features are generally less than the resolution limit of the exposure tool used and do not print out on the layer. The optical proximity features provide a transition region between fully exposed material and un-exposed material, which results in a sloped sidewall of the photo-sensitive material after development. The sloped sidewall provides a more reliable thin film metal layer to contact through vias, and may be used to conserve wiring board area by allowing smaller via spacing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.