Bump formation method
US6146920A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jul 10, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Jul 10, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/5142
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for forming bumps in an LSI package in which: semiconductor chips are mounted onto a flexible printed circuit board; electrically conductive balls are temporarily fixed by using a fixing liquid including one selected from a group including flux, solder paste and an adhesive containing an electrically conductive agent, onto pads which are provided on the flexible printed circuit board so as to be electrically connected to the semiconductor chips; the flexible printed circuit board having the electrically conductive balls temporarily fixed thereto is wound up onto a reel; the flexible printed circuit board having the electrically conductive balls temporarily fixed thereto is fed out from the reel and heated to thereby form bumps thereon; and the flexible printed circuit board having the bumps formed thereon is wound up onto another reel; and the flexible printed circuit board is cleansed and trimmed to thereby form LSI packages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.