333 / 2022-03-15 15:30:31

Research on Field Strength Optimization Method of High Voltage Semiconductor Packaging Based on Dielectric Functionally Graded Materials

Field strength optimization,Dielectric functionally graded materials,Electrophoresis,Semiconductor Packaging

Purpose/Aim

High voltage IGBT (Insulated Gate Bipolar Transistor) is the most significant equipment in new energy industry. As the voltage level increases, the problem of insulation breakdown caused by electric field distortion at the triple point of the IGBT becomes more and more prominent. In this paper, a preparation method of dielectric functionally graded materials based on electrophoresis was proposed to optimize the local electric field, and the influence of process parameters and material parameters on the optimization effect was analyzed, which provided a new idea for improving the insulation performance of high voltage IGBT.

Experimental/Modeling methods

BaTiO₃ was used as filler particles to add silicone gel mixture and poured into the mold. Electrophoretic force was applied in the mixture to construct dielectric functional gradient materials, and then the aggregated particles were frozen by curing. The dielectric properties of samples under different voltage amplitude, voltage application time and particle concentration were analyzed by scanning electron microscope, dielectric spectrum and partial discharge detection system, and the effects of different parameters on the optimization effect of field strength were studied.

Results/discussion

With the increase of voltage amplitude, application time and particle concentration, the thickness and density of the deposited layer increase, and the overall dielectric constant presents a continuous gradient distribution. Compared with pure silicon gel insulation, the PD initiation voltage of dielectric functionally graded insulation decreases significantly.

Conclusions

In this paper, the preparation of dielectric functional gradient materials in the local area of IGBT was realized based on electrophoresis technology. It is found that the distribution state of dielectric gradient materials can be controlled by controlling the amplitude, application time and particle concentration, which provides technical support for the accurate optimization of local electric field of high voltage IGBT.