Power Device Packaging

The Need for Void-Free

The trend today in power electronics is to move towards smaller form factors while maintaining or increasing overall power requirements.  As these power densities increase, proper thermal management becomes more and more vital in order to meet today’s tighter reliability standards.  As a result, void-free solder joints and connections are now a must.
Vacuum assisted reflow remains one of the best methods for achieving void free solder connections, and is widely used in the power device packaging industry.  Heller Industries has hundreds of vacuum oven systems in the field with a proven ability to reduce solder voids to <1%.  Heller offers a multitude of vacuum reflow oven models suitable for all product sizes and volumes.  Heller vacuum ovens offer closed-loop vacuum pump control, IR heated chambers, and an optional staging conveyor system capable of providing the fastest product transfer times into and out of the vacuum chamber, maximizing overall throughput.
Voids in power electronics can be reduced even further by incorporating a fluxless process (which is often combined with the vacuum process, learn more about formic acid reflow.)  Fluxless processing is normally done using formic acid, although in cases where peak temperatures are high (over 350°C) forming gas is a better option.  Both formic acid and forming gas are fluxless options offered by Heller.