Fabrication of a PCB-embedded Half-Bridge Module

Embedding power semiconductor devices into printed circuit boards (PCB) has been investigated for several years. With this technology the PCB is built-up around a bare semiconductor chip. Compared to the conventional approach, where packaged semiconductors are soldered to a PCB, which serves as circuit carrier only, embedding of power semi- conductors (such as MOSFET or IGBT) offers several benefits:

1. Embedding reduces the device volume significantly, as no package for the semiconductor is required.

2. Miniaturization shortens the power loop and results in reduced parasitics (resistance and inductance). This enables lower switching and conduction losses.

3. Using thick Cu substrates for heat spreading enables an improved thermal impedance [3, 4]. Today, the technology is available from a few specialized PCB manufacturers, who offer production only for high volume applications. Here, we present an approach for prototyping of multi-layer PCBs with embedded power semiconductor. A demonstrator board with an embedded MOSFET half bridge is developed, fabricated, and tested.