Flip chip assembly method employing post-contact differential heating
US8381966B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2011 |
| Grant date | Feb 26, 2013 |
| Priority date | — |
| Expiry date | Feb 28, 2031 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K1/0016
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A first substrate mounted to a bonder head and a second substrate mounted to a base plate are held at different elevated temperatures at the time of bonding that provide a substantially matched thermal expansion between the second substrate and the first substrate relative to room temperature. Further, the temperature of the solder material portions and the second substrate is raised at least up to the melting temperature after contact. The distance between the first substrate and the second substrate can be modulated to enhance the integrity of solder joints. Once the distance is at an optimum, the bonder head is detached, and the bonded structure is allowed to cool to form a bonded flip chip structure. Alternately, the bonder head can control the cooling rate of solder joints by being attached to the chip during cooling step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.