Alumina ceramic substrates are widely used as packaging carriers for LEDs, IGBTs, and sensors due to their excellent insulation and thermal conductivity characteristics. The thermal conductivity of a substrate directly determines the heat dissipation efficiency of a device. Operating heat from the chip needs to be rapidly conducted outward through the substrate; excessively high thermal resistance in the substrate can lead to the chip’s temperature rising beyond limits, thereby shortening the service life of the components. Deeply rooted in the research, development, and production of magnesium oxide, Messi Biology utilizes high-purity magnesium oxide powders to regulate the crystal phase of alumina, optimizing thermal conductivity performance while ensuring substrate densification.
Heat conduction in alumina ceramics primarily relies on lattice vibrations, with grain boundaries and internal pores serving as the main sources of thermal resistance. Adding an appropriate amount of magnesium oxide pins the grain boundaries during the high-temperature sintering stage, inhibits abnormal grain growth, reduces enclosed pores within the green body, increases substrate densification, and lowers the thermal resistance caused by pores. Simultaneously, magnesium oxide reacts with alumina to form magnesium-aluminum spinel, which is uniformly distributed along the grain boundaries without forming large areas of low-thermal-conductivity glass phase. Under a rational formulation ratio, the substrate maintains a good level of thermal conductivity while comprehensively enhancing its insulation and mechanical properties.
When adjusting formulations, many substrate manufacturers tend to sacrifice thermal conductivity in pursuit of densification, or achieve target thermal conductivity only to find the substrate strength insufficient. The magnesium oxide modification solution achieves a multi-index balance: it enhances the degree of substrate densification while also balancing flexural strength and insulation performance, making it well-suited for the demands of medium- and high-power device substrates.
For high-power LED substrates and automotive electronic substrates, operating temperatures fluctuate significantly over long periods, making stable thermal conductivity and reliable insulation the foundation for stable device operation.
Powder quality has a pronounced impact on the ultimate thermal conductivity index. If the magnesium oxide powder contains excessive silicon and calcium impurities, they will form a low-melting-point glass phase enriched at the grain boundaries during high temperatures, which will significantly increase thermal resistance.
The magnesium oxide powder produced by Messi Biology undergoes purification treatment, with strict control over harmful impurities, stable particle size distribution, and uniform dispersion during the mixing process, thereby preventing local impurity aggregation. Enterprises can determine the addition amount through small-scale trials to match their own sintering processes. Amid the ongoing trend of power devices developing toward miniaturization and higher power, relying on magnesium oxide formulation modification allows alumina substrate manufacturers to continuously optimize the thermal performance indices of their substrates and meet the heat dissipation demands of downstream electronic components.