High-power semiconductor devices play a vital role in modern power electronics systems, and are widely used in new energy vehicles, power transmission, industrial control, aerospace and communication equipment. However, in high-power operating environments, these semiconductor devices generate a significant amount of heat, which can lead to degraded performance, reduced reliability, and even device failure if not dissipated effectively.
Therefore, the selection of packaging materials is particularly critical to combine high thermal conductivity, low coefficient of thermal expansion (CTE) and excellent mechanical properties. Molybdenum-copper (Mo-Cu) alloy has become one of the important materials for high-power semiconductor packaging due to its excellent thermal management ability, good thermal matching performance and high stability.
High-power semiconductor devices, such as IGBTs (insulated gate bipolar transistors), MOSFETs (metal oxide semiconductor field effect transistors) and SiC/GaN power devices, operate in high-voltage, high-frequency, and high-current environments, and their packaging materials need to meet the following core requirements:
1. High thermal conductivity
Since semiconductor devices generate a lot of heat, the packaging material must have good thermal conductivity to quickly conduct heat to the heat sink and prevent the device from overheating.
2. Matching coefficient of thermal expansion (CTE)
Semiconductor chips (such as silicon Si, silicon carbide SiC, gallium nitride GaN) have a low coefficient of thermal expansion, and the CTE of the packaging material should be matched to the chip to reduce thermal stress and improve the reliability of the device.
3. High mechanical strength and stability
Encapsulation materials need to withstand long-term thermal cycling and mechanical stress to ensure stable operation in a variety of extreme environments.
4. Good corrosion resistance and electrical properties
The encapsulation material should have good oxidation resistance and corrosion resistance to ensure long-term use in high temperature and high humidity environments, and at the same time have good conductivity to reduce energy loss.
The main applications of molybdenum-copper alloys in high-power semiconductor packaging include:
1.Heat Spreader
In IGBT, MOSFET and other power device packaging, Mo-Cu alloy is used as a heat sink material, which can efficiently conduct the heat generated by semiconductor chips to the heat dissipation system, reduce the chip temperature, and improve the reliability and efficiency of the device.
2.Substrate
The Mo-Cu substrate can be used as a thermal buffer layer between the chip and the heat sink, which can effectively reduce thermal stress and improve the stability of the device. Especially in new semiconductor packages such as SiC and GaN, Mo-Cu alloy has become an ideal substrate material due to its good thermal matching.
3.Lead Frame
Mo-Cu alloy can be used in the lead frame of IGBT and MOSFET to provide mechanical support, while optimizing electrical conductivity, reducing parasitic resistance and power dissipation, and improving power conversion efficiency.
4.Package Housing
In high temperature, high humidity and high vibration environments, Mo-Cu alloy can be used in the package housing of power modules to improve structural strength and heat dissipation capacity.
