Method of making a bump on a substrate without ribbon residue
US6696356B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 2001 |
| Grant date | Feb 24, 2004 |
| Priority date | — |
| Expiry date | Dec 31, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/30107
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming a bump on a substrate such as a semiconductor wafer or flip chip without producing metal ribbon residue. The method includes the step of providing a semiconductor device having a contact pad and having an upper passivation layer and an opening formed in the upper passivation layer exposing a portion of the contact pad. An under bump metallurgy is deposited over the upper passivation layer and the contact pad. A photoresist layer is deposited over the under bump metallurgy. The photoresist layer is a dry film photoresist. The photoresist layer is patterned to provide an opening in the photoresist layers down to the under bump metallurgy and aligned with the contact pad. Additional energy is applied to the photoresist layer to improve the adhesion of the photoresist layer to the under bump metallurgy. An electrically conductive material is deposited into the opening formed in the photoresist layers and overlying the under bump metallurgy and aligned with contact pad. Thereafter the remaining portions of the photoresist layer are removed. The electrically conductive material is reflown to provide a bump on the semiconductor device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.