2006 R&D 100 Winner
Tin/silver/copper alloys have already been adopted as the primary lead-free technology by most electronics manufacturers. The industry has been limited, however, by the availability of this composition only as screenable paste and solder balls. A new plating technology developed by Rozalia Beica at Rohm and Haas Electronic Materials, LLC, Freeport, N.Y., delivers fine-grained, smooth, solderable reflowed solder bumps with consistent deposit composition. The process, High Speed Tin/Silver/Copper Electroplating Process for Wafer Bumps, is a low-foaming, organic sulfonate electroplating process for the high-speed deposition of uniform, fine grain, matte tin/silver/copper from a single plating solution.
This technology is applied through a one step electro-deposition process from a very stable acidic system. The process applicability and control is compatible with the equipment currently existing in fabrication facilities. Besides the cost-effective advantage that comes with an electro-deposition process, additional cost savings are achieved by the significant improvement in throughput of this process compared with the current lead free production offerings.
Low-foaming, organic sulfonate electroplating process
Originally published in R&D Magazine, September, 2006