Indium’s new package-attach solder preform technology

This technology facilitates lower processing temperatures in preform soldering tasks.

Developed for power module package-attach purposes, Indalloy 301-LT is a non-bismuth alloy that aims to prevent thermal defects in modules without affecting the dependability commonly compromised by traditional low-temperature, bismuth-containing alloys.

Offered in InFORMS configurations, Indalloy 301-LT serves as a solution for achieving uniform bondline thickness and enhanced strength. This strengthens the thermal and mechanical integrity of the solder joint and reduces the temperature and energy needed in the manufacturing process. It complements Pb-free, high-reliability alloy technologies such as Indalloy 276 for power module die-attach, component-attach, or interconnects, all without the risk of re-melt and compromised performance. Indalloy 301-LT is also accessible in preforms and ribbon formats and can be provided either with or without Indium Corporation's flux coating technology.

Product Manager Joe Hertline explained: "With increasing mission profile demands in power electronics applications, such as EV power module-cooler integration, preform soldering offers superior thermal and mechanical performance compared to traditional thermal interface materials. By leveraging this new alloy technology in package-attach applications, designers can prevent warpage, encapsulation breakdown, and delamination issues by reducing processing temperature, making preform soldering a viable approach with robust thermal and mechanical reliability performance."

Characteristics of Indalloy 301-LT consist of:

• Reduction in reflow peak temperatures by 50°C when compared to commonly used alloys in power electronics assembly
• Prevention of warpage and delamination in molded power module package-attach
• Capability to step-solder with Pb-free alloys
• Exceptional thermal and electrical conductivity
• Consistent reliability performance (TST -40°C–125°C)
• Minimised energy consumption
• Availability in forms such as preforms, ribbons, and InFORMS