Thermal interface impedance control and reliability evaluation of passivated magnesium powder thermal conductive composite materials for electronic devices

With the trend towards miniaturization and high performance of electronic devices, heat dissipation has become increasingly critical. Passivation magnesium powder thermal conductive composite materials have shown broad application prospects in the field of electronic device thermal management due to their excellent thermal conductivity. However, to fully utilize its performance, it is necessary to effectively regulate the thermal interface impedance and conduct reliability assessments.

The thermal interface impedance is an important factor affecting the heat dissipation efficiency of electronic devices. When passivated magnesium powder thermal conductive composite materials come into contact with electronic device chips, heat sinks, etc., there will be thermal interface impedance at the interface, which hinders the effective transfer of heat between various components. Regulating the impedance of the thermal interface can be approached from multiple aspects. Firstly, optimize the particle size and morphology of passivated magnesium powder. Smaller particle size can increase the contact area between magnesium powders, reduce the gaps between interfaces, and lower thermal resistance. Meanwhile, magnesium powder with regular morphology, such as spherical shape, is more conducive to close packing and further reduces thermal interface impedance. Secondly, add an appropriate amount of high thermal conductivity fillers such as carbon nanotubes, graphene, etc. to the composite material. These fillers can form thermal conduction channels between magnesium powders, accelerate heat conduction, and thereby reduce thermal interface impedance. In addition, treating the contact surface can also have a positive effect. By using methods such as surface polishing and chemical etching, the surface roughness is reduced, allowing the composite material to better adhere to the contact parts and reducing heat flow obstruction caused by uneven surfaces.

Reliability assessment is an important step in ensuring the stable application of passivated magnesium powder thermal conductive composite materials in electronic devices. During long-term use, composite materials are affected by various environmental factors such as temperature, humidity, and mechanical stress. The temperature cycling test can simulate the temperature changes of electronic devices in actual operation, and investigate the performance stability of composite materials during repeated thermal expansion and contraction processes. Evaluate its thermal fatigue resistance by measuring the variation of thermal interface impedance with the number of temperature cycles. The humidity test is used to test the corrosion resistance and insulation performance of composite materials in high humidity environments. Humidity may cause chemical reactions or electrochemical corrosion inside materials, affecting their thermal and electrical properties. Mechanical stress tests, such as vibration tests and impact tests, can verify the structural integrity and thermal stability of composite materials under external forces.

In addition to the environmental tests mentioned above, it is also necessary to monitor the long-term thermal conductivity of composite materials. Regularly measure its thermal conductivity and thermal interface impedance, and observe the trend of performance changes over time. If a significant decrease in performance is found, the reason needs to be analyzed, which may be due to changes in the internal microstructure of the material, such as magnesium powder oxidation, filler agglomeration, etc.

The thermal interface impedance control and reliability evaluation of passivated magnesium powder thermal conductive composite materials for electronic devices is a systematic engineering. By using reasonable control measures to reduce thermal interface impedance, improve heat dissipation efficiency, and conducting comprehensive reliability assessments, we ensure that materials work stably and reliably under various environmental conditions, providing strong guarantees for efficient heat dissipation of electronic devices.