Fabrication method of strengthening flip-chip solder bumps
US6821876B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 26, 2003 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Mar 26, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/014
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A fabrication method for strengthening flip-chip solder bumps is provided to form a solder bump on a UBM (under bump metallurgy) structure formed over a semiconductor chip, which can prevent the UBM structure against oxidation and contamination and also enhance bondability between the solder bump and UBM structure, thereby improving reliability for packaging the semiconductor chip. This fabrication method is characterized in that before forming the solder bump, a dielectric layer made of BCB (benzo-cyclo-butene) or polyimide is deposited on the UBM structure, and used to protect the UBM structure against oxidation and contamination. Further, before forming the solder bump, a plasma-etching process is performed to remove the dielectric layer; the plasma-etching process is environmental-friendly without having to use a chemical solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.