Series 11 – Episode 10 – LFPAK: a technological innovation
Paige West speaks with Chris Boyce, Senior Director, Marketing & Product Group, BG MOS Discretes, Nexperia about LFPAK technology.
Created by Nexperia two decades ago, LFPAK revolutionised the semiconductor industry with a unique, clip-bond package for power MOSFETs.
“If you go back 20 years, electronic power components, power transistors, were typically based on what we call wire bonds,” notes Boyce. “If you can imagine, it comes from the IC world, that you have a piece of silicon and you connect that then to the package with a bunch of bonding wires that kind of connect from the surface of the silicon to the lead frame and hence to the pins and the outside world.
“In particular, they are taking really high current and those bonding wires, the internals of the package, were a limitation in terms of the performance of the device.
“So, the kind of innovative step if you like, of LFPAK was to take (these are vertical devices, so the current is flowing through the surface of the silicon) a copper lead frame, we put down some solder, we put down the silicon chip, you put down some more solder, and then we put a copper clip on top.
“So, essentially you’ve got a sandwich of the silicon between two pieces of copper, and doing away entirely with those wire bonds. And that allowed us to produce devices that were much higher performance.”
This technology would set new standards in MOSFETs that quickly became the benchmarks which have remained in place to this day.
But it took some effort to persuade the industry that the device half the size of its predecessor could have the same thermal performance, and the innovative copper clip is in fact more reliable than the bond wires.
Boyce goes on to discuss why the technology was so revolutionary, how LFPAK technology is benefitting the automotive industry and how Nexperia is continuing to refine and improve LFPAK technology.