In modern power electronics systems, the IGBT (insulated gate bipolar transistor) module is the core component of energy conversion and control, and its long-term stability and reliability are very important. As the key component of IGBT module package structure, ceramic clad substrate not only carries the circuit components, but also bears the heavy task of heat conduction, which directly affects the heat dissipation efficiency and service life of the module. This paper aims to explore the influence of different ceramic substrate materials on the performance of ceramic copper clad plate, especially from the perspective of thermal conductivity and thermal expansion coefficient matching, analyze the advantages and disadvantages of alumina, silicon nitride and aluminum nitride ceramic substrate materials, in order to provide a theoretical basis for the selection of high power module packaging materials.
Application limitations of alumina substrates: Although alumina ceramic substrates are widely used due to their cost effectiveness and proven processes, their relatively low thermal conductivity and mismatch with the thermal expansion coefficient of silicon materials limit their application potential in high power density modules.
Prospects and challenges of silicon nitride substrates: Silicon nitride ceramics are known for their excellent overall performance, especially in high temperature environments. However, the actual thermal conductivity of silicon nitride ceramics is much lower than the theoretical value, and the research and development of high thermal conductivity silicon nitride ceramics is still in the laboratory stage, which becomes a key factor restricting its wide application.
Advantages of aluminum nitride substrate: With excellent thermal conductivity and thermal expansion coefficient similar to semiconductor materials (such as Si), aluminum nitride copper clad plate effectively solves the thermal management problem of IGBT module, reduces internal stress, significantly improves the reliability and service life of the module, and is regarded as the ideal substrate material for power electronic device packaging.
The main properties of the three ceramic substrate materials are compared in detail (as shown in Table 1). Although the alumina substrate has a high popularity, the problem of insufficient thermal conductivity and mismatch of thermal expansion coefficient has become increasingly prominent, especially in high-power modules, which may lead to increased thermal stress and affect the stability and life of the module. Although the overall performance of silicon nitride substrate is superior, but limited by the actual thermal conductivity, it is difficult to meet the demand for high thermal conductivity, and its commercialization process still needs time. In contrast, aluminum nitnitide copper clad plate with its high thermal conductivity and good thermal expansion coefficient matching, become the key to solve the IGBT module thermal management problem, not only accelerate the heat conduction, but also reduce the internal stress caused by the difference in thermal expansion, thereby improving the reliability and durability of the module.
In summary, the selection of ceramic substrate materials is crucial to the long-term performance of IGBT modules. Among the three materials of alumina, silicon nitride and aluminum nitride, aluminum nitride copper clad plates show great advantages in high-power module packages due to their excellent thermal properties and good matching with semiconductor materials. In the future, with the continuous progress of material science and the optimization of preparation technology, aluminum nitride ceramic substrates are expected to become the key materials to promote the development of higher power density and higher reliability in the power electronics industry. Therefore, for specific application scenarios, reasonable selection of ceramic substrate materials is of great significance for improving the overall performance and extending the service life of IGBT modules.
