Indium Blog

Why Do We Need to Go Thinner?

For the plethora of applications that require a high-melting die-attach solder, 80Au20Sn is a great choice to ensure good performance and reliability. Typical applications for 80Au20Sn in die-attach include: butterfly packages and diodes, optical packages and diodes, and SFPs (small form-factor pluggable) transceivers.  One of the most popular applications for 80Au20Sn is in semiconductor laser die-attach, primarily due to recent advancements that have made lasers an economical option for a multitude of new products. 80Au20Sn is commonly used with high output lasers due to its good thermal conductivity; high sheer, yield, and tensile strangth; excellent wettability; and resistance to corrosion.

A key challenge with semiconductor lasers is thermal management as these devices generate a significant amount of heat. The semiconductor laser performance will decrease as the temperature increases, limiting its potential. Any improvement in thermal release from the die to the substrate directly impacts the overall operational efficiency and performance of the device. To help facilitate thermal transfer from the die to the substrate you must reduce the bond line thickness (BLT). A thinner preform will reduce the BLT, allowing the heat to transfer away from the die more quickly, thereby increasing the longevity and performance of the die.

With the industry standard of a using a 0.0005” preform, Indium Corporation created an even thinner preform for high-output laser applications called AuLTRA™ ThInFORMS™, an 80Au20Sn preform with a thickness of 0.00035”. These preforms provide a thinner BLT, therefore improving the thermal transfer and operational efficiency of high-output lasers by reducing voiding, solder volume, and wicking up the die. Blanking preforms (rectangles, squares, and discs) are available now.

If you have any questions, or for more information about our AuLTRA™ ThInFORMS™, please contact me at


Jenny Gallery

High-Temp Gold and Braze Product Specialist