Process for producing flip chip circuit board assembly exhibiting enhanced reliability
US5953814A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1998 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Feb 27, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49146
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A process and combination of materials for underfilling a surface-mount IC device (12), such as a flip chip, for the purpose of increasing the thermal cycle fatigue life of the terminals (14) that attach the device (12) to a thin-laminate organic circuit board (10), such as a printed wiring board (PWB) or printed circuit board (PCB). The process parameters and materials, including the underfill (20), masking (22) and cleaning materials used, exhibit a synergistic effect that increases thermal cycle fatigue resistance to a level at which a flip chip processed in accordance with this invention is capable of reliably withstanding at least 1000 one-hour cycles between -40.degree. C. and 150.degree. C. The materials and the manner in which the device (12) and circuit board (10) are prepared for application of the materials are critical to eliminating tendencies for inconsistent reliability in underfilled SM devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.