Abstract
In flip chip packaging, underfill process is used to fill epoxy bonder into the gap between a chip and a substrate in order to improve the reliability of electronic devices. Underfill process by capillary motion can give rise to unwanted air void formations since the arrangement of solder bumps affects the interfacial dynamics of flow meniscus. In this paper, the unsteady flows in the capillary underfill process are visualized and then the racing effect and merging of the meniscus are investigated according to the arrangement of solder bumps. The result is shown that at higher bump density, the fluid flow perpendicular to the main direction of flow becomes stronger so that more air voids are formed. This phenomenon is more conspicuous at a staggered bump array than at a rectangular bump array.
| Translated title of the contribution | Visualization for racing effect and meniscus merging in underfill process |
|---|---|
| Original language | Korean |
| Pages (from-to) | 351-357 |
| Number of pages | 7 |
| Journal | 한국마린엔지니어링학회지 |
| Volume | 37 |
| Issue number | 4 |
| DOIs | |
| State | Published - May 2013 |