Apparatus and method for forming solder bonding pads
US5873511A · kind A · utility
Inventor
Key dates
| Filing date | Jun 17, 1997 |
| Grant date | Feb 23, 1999 |
| Priority date | — |
| Expiry date | Jun 17, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05K2203/107
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The placement of solder "balls" in a Ball Grid Array is accomplished by placing a solder strip in contact with the top surface of the ball grid array carrier. The pulsing of a laser directed at the solder in discrete positions permits the transfer of the solder to the gold dot, of the array of dots, on the carrier in registry with the laser output when activated. Selective solder placement is possible and increasingly higher throughput is achieved by the use of laser diode bars or optical fiber fans to effect solder transfer to a plurality of dots of the array simultaneously. The entire process can be automated by making the solder strip continuous through a recycling station arranged along a path along which the solder strip moves to the position where the carrier and the solder strip are moved into juxtaposition. The use of a transparent strip with a pattern of holes filled with solder paste permits easy transfer of the solder to the gold dots or islands on the carrier in registry with laser beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.