Silicon Carbide (SiC) power devices have attracted much attention due to their advantages such as wide bandgap, high voltage resistance, high temperature, low on-resistance and fast switching. However, how to give full play to the performance of silicon carbide devices has brought new challenges to packaging technology. Traditional packaging technologies face many problems when dealing with the fast switching characteristics of silicon carbide devices, such as large stray inductance parameters, poor reliability at high temperatures, and the need for multi-functional integrated packaging and high power density.
1. Low stray inductance packaging technology
Single-tube flip chip package: Drawing on BGA packaging technology, a single-tube flip chip package is adopted, and the back electrode of the chip is flipped to the same plane position of the front electrode through the metal connector, so as to eliminate the metal bonding wire, reduce the volume and improve the on-resistance.
DBC+PCB hybrid packaging: Combined with the DBC process and the PCB board, the upper surface of the chip is connected to the PCB board by using metal bonding wires, and the commutation loop is controlled between the PCB layers, reducing the current loop area, effectively reducing the stray inductance parameters and improving the performance.
Front-side planar interconnect package: The connection method of planar interconnect, such as the direct connection soldering method of the terminal, realizes the connection of the front of the chip, reduces the current loop, and improves the temperature cycling characteristics and reliability.
2. High temperature packaging technology
Flexible PCB board combined with sintered silver process: The flexible PCB board combined with sintered silver process is used for packaging, replacing the bonding wire, realizing electrical connection, effectively reducing stray inductance parameters, reducing volume, and improving power density.
Embedded packaging: The chip is placed in a ceramic positioning slot, and the gap is filled with insulating medium and covered with metallic copper to realize the electrode connection, reduce the interlayer thermal stress of the module at high temperature, and improve the forward and reverse characteristics.
3. Multi-functional integrated packaging technology
Planar direct-attach package: Eliminate metal bonding wires, expand the current loop from the DBC board plane layout to the interlayer layout of the upper and lower planes of the chip, reduce the loop area, and achieve low stray inductance parameters.
Double-sided thermal packaging and three-dimensional packaging: By changing the packaging method, better heat dissipation is achieved and power density is improved.
Through the analysis of these three key technical directions, we can see that the packaging technology of silicon carbide power devices is constantly innovating and developing. The application of these technologies will promote the wider application of silicon carbide power devices in the field of power electronics while improving device performance, reliability and adapting to a wider range of applications.