Double mask hermetic passivation method providing enhanced resistance to moisture
US5736433A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1996 |
| Grant date | Apr 7, 1998 |
| Priority date | — |
| Expiry date | Dec 31, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A passivation structure is formed using two passivation layers and a protective overcoat layer using two masking steps. The first passivation layer is formed over the wafer and openings are provided to expose portions of the pads for testing the device and fusible links. After testing and laser repair, a second passivation layer is formed over the wafer followed a deposit of the protective overcoat. The protective overcoat is patterned and etched, exposing the pads. The remaining portions of the protective overcoat are used as a mask to remove portions of the second passivation layer overlying the pads. Leads are then attached to pads and the devices are encapsulated for packaging. The second passivation layer overlaps edge portions of the first passivation layer at the bond pads to enhance moisture resistance.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.