Method for fabricating metallization patterns on an electronic substrate
US5591480A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1995 |
| Grant date | Jan 7, 1997 |
| Priority date | — |
| Expiry date | Aug 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/095
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
One method for fabricating solderable pads (406) onto a substrate (220) for direct chip attachment uses a multilayer metallization coating (500). The coating has a bottom layer (202) of indium-tin oxide, with an intermediate layer (204) of copper and a top layer (206) of indium-tin oxide. A masking layer (208) is deposited on the active display area (402) of the substrate, leaving the bonding pads uncovered. The revealed bonding pads are then plasma etched, using the polyimide as an etch resist, and the top layer of ITO is selectively removed to reveal the underlying copper layer. The exposed copper layer (204) is then plated with a solderable metal to the desired thickness to form bonding pads that may be used with direct chip attachment schemes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.