Two Major Application Areas of Aluminum Nitride Ceramics in New Energy Vehicles

With the rapid advancement of microelectronics technology, electronic systems and components are moving toward miniaturization, Lightweight design, integration, higher reliability, and greater power output. The increasing complexity of devices places higher demands on the heat dissipation of substrates and packaging materials. Consequently, aluminum nitride (AlN) substrates, known for their high thermal conductivity, have become a "star material" in the field of heat dissipation substrates. In the new energy vehicle sector, they can even replace aluminum oxide substrates, demonstrating broad application prospects.

01 Application of Aluminum Nitride in New Energy Vehicles

AlN Ceramic Substrates for IGBTs
Amid the wave of "new four modernizations" in new energy vehicles, the demand for high-voltage, high-power IGBT modules is becoming increasingly urgent. High-voltage, high-power IGBT modules face high technical barriers and significant challenges, requiring packaging materials with excellent heat dissipation, high reliability, and greater current-carrying capacity. Ceramic copper-clad substrates, with their outstanding thermal conductivity, have become indispensable key materials in the packaging of power modules for the power electronics sector.

Ceramic Copper-Clad Substrate
Source: Fuluowa

Compared to Al₂O₃ and Si₃N₄ ceramic substrates, AlN ceramic substrates offer the following advantages: Using AlN ceramic substrates as the chip carrier isolates the chip from the module's heat dissipation baseplate. The intermediate AlN ceramic layer effectively enhances the module's insulation capability (ceramic layer insulation withstand voltage >2.5 kV). Moreover, aluminum nitride ceramic substrates exhibit excellent thermal conductivity, with a thermal conductivity coefficient ranging from 170–260 W/m·K. These superior properties make aluminum nitride copper-clad substrates the preferred choice for high-voltage IGBT module packaging.

Additionally, AlN ceramic substrates have a coefficient of thermal expansion similar to silicon, preventing stress damage to the chip. The peel strength of aluminum nitride ceramic substrates exceeds 20 N/mm², offering excellent mechanical properties, corrosion resistance, and minimal deformation. They can be used across a wide temperature range, thereby enhancing the reliability of high-voltage IGBT modules.

Aluminum Nitride for LED Headlights
The operating temperature of automotive LED headlights is extremely high. If heat cannot be dissipated promptly, it will accelerate brightness attenuation. In such cases, the performance of the LED heat dissipation substrate becomes critical. Aluminum nitride ceramic substrates, with their high thermal conductivity, excellent insulation, and thermal expansion coefficient better matched to LED chips, are an ideal choice for high-power headlights. Moreover, the applications of aluminum nitride ceramic substrates in automobiles extend beyond headlights, including various sensors and high-power modules for smart vehicles, indicating a highly promising future.

Source: pixabay

02 The Key to High-Performance AlN Ceramics Lies in Powder Preparation
Aluminum nitride powder preparation technologies can be categorized into direct nitridation, carbothermal reduction, self-propagating high-temperature synthesis (SHS), plasma methods, chemical vapor deposition, solution methods, and high-energy ball milling.

Common Methods for Aluminum Nitride Powder Preparation
Among these, carbothermal reduction dominates, accounting for nearly 50%, followed by direct nitridation and self-propagating methods at 26% and 12%, respectively. These three methods have also achieved industrial-scale application. They are relatively mature, require simpler equipment, and yield high-purity products. However, the formulations and steps involved in these processes are complex, energy consumption is high, and there are certain safety risks, all of which constrain the large-scale commercial application of aluminum nitride.

There is a gap between domestic aluminum nitride powder preparation technology and international standards in terms of high quality, both in quality and stability. Currently, the global market for aluminum nitride powder is primarily supplied by companies such as Japan's Tokuyama (holding 75% of the global market share for high-purity AlN powder), Toyo Aluminium, Germany's Starck, and the U.S.'s DOW Chemical, with product purity reaching 99.9%. Domestically, there are very few companies capable of mass-producing high-quality formulated powders (currently, two companies have entered the stage of introducing formulated powders).

03 Rapid Development of Domestic AlN Industry with Significant Import Substitution Potential
With the development of the semiconductor and new energy industries, there are increasing demands for heat dissipation in the packaging of high-power power electronics chips, optical chips, etc. Ceramic substrates are evolving from aluminum oxide toward aluminum nitride and Silicon Nitride. Although domestic companies currently hold a relatively low market share, this indicates significant potential for import substitution in the future.

Currently, the global production of Aluminum Nitride Substrates is dominated by a few manufacturers, with Japan being the largest exporter. Key core manufacturers include Maruwa and Kyocera. Manufacturing aluminum nitride substrates requires high-temperature sintering furnaces, which initially had to be imported from Japan at a cost of up to 6 million RMB per unit. It was not until 2015 that domestic technology breakthroughs were achieved. Today, a number of domestic companies have emerged with large-scale aluminum nitride substrate production capabilities, with leading companies achieving capacities exceeding 500,000 pieces per month, gradually approaching the level of Japan's Maruwa. With the continuous improvement in the production capacity of high-quality aluminum nitride substrates, the long-term reliance on imported high-performance ceramic substrates is expected to change.

The current market size for aluminum nitride ceramic substrates is approximately 1 billion RMB. From 2019 to 2022, the compound annual growth rate of the domestic aluminum nitride ceramic substrate market exceeded 20%. With the rapid development of downstream sectors such as large-scale integrated circuits, IGBTs, microwave communications, automotive electronics, and image sensing, coupled with the increasing power of electronic devices, the application scope of aluminum nitride will further expand. According to industry experts, the growth rate of the aluminum nitride ceramic substrate market is expected to remain above 20% in the coming years. At this growth rate, the market size for aluminum nitride ceramic substrates is projected to reach 2 billion RMB by 2026.