Tape ball grid array package with perforated metal stiffener
US5835355A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 22, 1997 |
| Grant date | Nov 10, 1998 |
| Priority date | — |
| Expiry date | Sep 22, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/15311
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A tape ball grid array (TBGA) package, and a method of making a TBGA package, includes the use of a metal or other stiffener affixed to a flexible tape on which conductive traces connect contact points on an integrated circuit (IC) chip with an array of solder balls. The stiffener is perforated with a pattern of small vent holes. The TBGA package materials are hygroscopic. When the TBGA package is heated during 2nd level packaging, e.g., during solder reflow, moisture absorbed within the hygroscopic materials evaporates and the resulting water vapor is able to escape through the vent holes, rather than becoming trapped within the IC package and introducing various 2nd level packing failure modes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.