UBM for fine pitch solder ball and flip-chip packaging method using the same
US7309924B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 2004 |
| Grant date | Dec 18, 2007 |
| Priority date | — |
| Expiry date | Oct 14, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A flip-chip package for implementing a fine solder ball, and a flip-chip packaging method using the same. The flip-chip package includes a first wafer having a first electrode and a first under bump metal (UBM) formed on the first electrode and electrically connected to the first electrode; and second wafer opposing the first wafer and having a second electrode located in a position corresponding to the first electrode, and a second UBM formed on the second electrode and electrically connected to the second electrode. The first wafer has a depression formed on one or more areas adjacent to the first UBM, which depression partly receives a solder ball that connects the first and the second UBMs upon flip-chip bonding of the first and second wafers. Since the UBM is formed as an embossing pattern, a fine solder ball can be implemented. Additionally, the reliability of the package can be improved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.