Dual-Leadframe Transient Liquid Phase Bonded Power Semiconductor Module Assembly and Bonding Process

John H. Glenn Research Center, Cleveland, Ohio

A high-temperature-capable widebandgap semiconductor power module package, coupled with a new high-temperature- capable bonding process (with an optimized assembly and manufacturing process), has been developed that, together, can allow device operation at temperatures exceeding 400 °C, with the potential for higher-temperature operation depending on the semiconductor device characteristics. The semiconductor module is an ultracompact, hybrid power module that uses double leadframes and direct lead-frame-to- chip transient liquid phase (TLP) bonding. The unique advantages include very high current-carrying capability, low package parasitic impedance, low thermomechanical stress at high temperatures, double-side cooling, and modularity for easy system-level integration. The new power module will have a very small form factor with 3 to 5× reduction in size and weight from the prior art, no failure-prone bond wires, and will be capable of operating from 450 to –125 °C.

An exploded view of the Semiconductor Module stackup.

Traditional power semiconductor modules use solder to attach the die to the substrate, which requires that the device be heated to a temperature higher than the normal operating temperature. For very-high-temperature-operation devices, it isn’t feasible to use a soldering process. However, in this innovation, the Transient Liquid Phase (TLP) bonds at a temperature between the operations temperature range of the device. It is also a low-cost manufacturing process.

A high-temperature module design may have a profound impact on power electronics and energy conversion technologies. For commercial applications, the new packaging and bonding process technology can be used in its current form, or can be scaled down to medium or conventional temperature ranges with a significantly reduced cost, making it a viable and economical option for large commercial markets such as hybrid electric vehicles, renewable energy conversion, and power supplies.

This work was done by John C. Elmes of Advanced Power Electronics Corporation, and Brian Grummel, Zehng John Shen, and Wendell Brokaw of the University of Central Florida for Glenn Research Center.

Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steven Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. LEW-19091-1/2-1