Reliability of Novel Ceramic Encapsulation Materials for Electronic Packaging

Abstract

Enhancements on power electronic systems with reduced chip area and miniaturized passive components are subject of several research activities in academics and industry. To realize such future electronic devices, it is necessary to incorporate wide bandgap semiconductor technology such as silicon carbide and gallium nitride operating at higher temperatures. Therefore, the development of novel materials with high thermal conductivities and stability, withstanding harsh environments up to 300°C is of major interest. Especially, polymeric encapsulation materials have to be improved because of common degradation effects above 175°C. Ceramic (nonpolymeric) materials with thermal conductivities above 5 W/(m·K) already illustrated promising results for the encapsulation of power electronics. The present work illustrates recent developments and improvements on novel ceramic encapsulation materials, which finally avoid critical interactions with the chip surface. Furthermore, advances in reliability will be discussed in terms of passed high-temperature reverse bias and humidity tests correlated with relevant material properties.

Sol–gel encapsulation for power electronics utilizing 3-Glycidyloxypropyltriethoxysilane and 3-Mercaptopropyltrimethoxysilane

“…However, several problems using these inorganic encapsulations were identified. Among them were corrosion of the metals, water uptake, limited potting time, and limited adhesion [8]. While corrosion of the metals and the water uptake could be reduced by measures concerning the recipe of the encapsulation, the potting time and the adhesion remain a bottleneck.…”

A Comprehensive Review of Mitigation Strategies to Address Insulation Challenges Within High-Voltage, High-Power-Density (U)WBG Power Module Packages

“…Practical data reveals that SG exhibits a TC and CTE of 0.17 W/(m⋅K) and 1000 ppm/K, respectively. On the other hand, EP demonstrates a TC of 1 W/(m⋅K) and a Tg of 135°C, as documented in [44]. This underscores the ongoing challenge of aligning encapsulant properties with the exacting requirements of advanced (U)WBG power modules.…”

“…It is observed that EPs are desired for power module packaging due to their higher dielectric strength (>20 kV/mm), lower water absorption rate (<0.1%), higher TC (>0.8 W/m-K), and lower CTE (<8/38 ppm/K). However, EPs' lower Tg (<135 o C) hinders their performance below 200 o C. Additionally, the viscosity of EPs (> 50 Pa.s) is significantly higher than SG and the desired limit of high-temperature encapsulant [44], [45]. This hinders the easy flow of the material in power modules, which leads to the formation of voids, bubbles, and defects that accelerate insulation aging.…”

The preparation of silicon carbide and its corresponding properties for electronic packaging applications

“…In fact, the non-method above was economic or convenient to manufacture in nowadays industry practice. Anyway, our group got a new way to realize the manufacture of SiC for packaging material using at a very low producing temperature and could utilize at a high temperature [8][9][10] .…”