GaN and SiC require a new approach to packaging
IDTechEx Research says that higher power densities mean we will see the growing use of sintered metal pastes
A generational shift is taking place in power electronics. New semiconductor technologies such as SiC and GaN are enabling smaller and more integrated devices capable of handling higher power density levels. With these, the bottleneck against higher temperature operation is not the semiconductor device but the packaging material.
A critical packaging material is the die (and to a lesser extent substrate) attach. The push towards higher temperatures has, in some cases, already pushed solder, the incumbent, to or beyond its performance limit, creating the need for an alternative. The need to sustain the roadmap towards higher temperature will only aggravate the challenge.
Sintered metal pastes have emerged as a compelling proposition. They increase the thermal conductivity and the melting temperature, allowing devices to reliability operate at higher temperatures. This technology is already in commercial use after some seven years of development and its markets will expand as the shift towards new semiconductor technologies further accelerates.
Sintered metal paste technology is improving. The development targets are to achieve rapid low (or zero) pressure sintering of ever larger surface areas and to narrow the significant price differential versus SAC solder. There is innovation in the material system.
Ag is dominant but promising Cu alternatives have also emerged with friendlier sintering conditions. Nano or hybrid (nano + micron) are positioning themselves as alternatives to traditional solutions based on micron-sized particles. The short-term promise is to lower the sintering temperature whilst the long-term one is to eliminate it altogether. Suppliers are also diversifying the product form factor, moving beyond just screen or stencil printing, to make the product more of a drop-in replacement. Machines makers are now offering turn-key solutions, integrating the pick-and-place, the drying, the pressure sintering units.
IDTechEx Research's report 'Conductive Ink Markets 2019-2029: Forecasts, Technologies, Players' provides a detailed analysis of this growing field.