ECTC 2015 featured a special session on sustainability in microelectronics, during which Qualcomm's Michelle Lee talked about the company's strategy to drive long-term growth and profitability through the inclusion of environmental, social and corporate governance. Part of this effort involves promoting social and ethical responsibilities in the supply chain. As such, she said Qualcomm has adopted a code of conduct that includes adherence to the RoHS and REACH initiatives; part of which calls for manufacture of lead-free devices.
At Dow Electronic Materials, we've been working for quite some time to develop a line of lead-free advanced packaging materials that help manufacturers comply with RoHS and REACH, while ensuring a level of reliability equivalent to lead-based materials. Take, for example, our newest, versatile tin-silver (SnAg) solder electroplating formulation for advanced bumping technologies. This product was developed to address the ever-widening process window for advanced packaging applications.
Lead-free, tin-silver mushroom bump formation
A little background on what brought us here: lead-free SnAg bumps have become the industry standard in high-volume production lines for a number of bumping technologies from legacy C4 bumps to Cu pillars capped with SnAg to 3D µbumps. The latter has brought forth some challenging requirements from IDMs, foundries and OSATS. They all want tightly controlled thickness uniformity, alloy composition uniformity and no reflow voids.
The SnAg plating chemistry that can meet these requirements and serve the wide process window reliably at the same time must be versatile and robust in both formulation and plating process.
The presentation, Versatile Lead-Free Solder Electroplating Products for Advanced Bumping Technologies, first presented at IMAPS Device Packaging Conference in 2014, demonstrates key performance attributes of SOLDERON™ BP TS6000 SnAg, over a wide range of applications.