Method of forming a small pitch torch bump for mounting high-performance flip-flop devices
US6740577B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 21, 2002 |
| Grant date | May 25, 2004 |
| Priority date | — |
| Expiry date | May 21, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/351
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A torch bump is provided, which is a solder bump comprising a base over which a solder bump is created. A first layer of dry film is over a supporting surface over which first a layer of UBM has been deposited. A base for the solder bump is created in a first opening through the first layer of dry film, the base aligns with an underlying contact pad. A second dry film is over the surface of the first dry film, a second opening is created through the second dry film that aligns with the created base of the solder bump. The opening through the second dry film is filled with solder by solder printing, the first and second layers of dry film are removed, the deposited layer of UBM is etched. Reflow is applied to the deposited solder, creating the torch solder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.