在电动汽车的迅捷运行、光伏电站的稳定运行以及工业生产线的精准控制背后，都离不开一个共同的核心功率元件——IGBT（绝缘栅双极型晶体管）模块。它将直流电转换为交流电，精确调节电机转速和扭矩，高效控制功率开关，完成电能的转换和调节，堪称电力电子设备的“心脏”。

随着行业不断提升系统性能和效率，IGBT模块正朝着更高功率密度、更小尺寸和更高可靠性的方向发展，以满足电动汽车轻量化、高功率输出、新能源逆变器高效运行以及工业变频设备长寿命和高可靠性的需求。在这些高功率、高热负荷的应用中，如何安全高效地散发芯片产生的热量，已成为模块设计中的一大挑战。

答案其实隐藏在模块中一个看似不起眼的部件——基板之中。它并非普通的金属板，而是由铜-陶瓷-铜复合结构制成的精密元件。传统上，IGBT 模块的基板采用陶瓷材料。对于低功率模块，通常使用成本低廉且制造工艺成熟的氧化铝。然而，在高功率、高可靠性应用中，由于氮化铝具有高导热性和优异的绝缘性能，已成为现代 IGBT 基板的关键材料。

为什么选择氮化铝？

氮化铝是一种先进的功能陶瓷。由于其优异的物理性能，它被用于高性能 IGBT 模块：

(1) 优异的导热性：导热系数高达 170–230 W/mK，是传统氧化铝的 6–8 倍，能够将芯片产生的热量快速传递到基板，从而防止过热和故障。

(2) 可靠的绝缘：氮化铝 (AlN) 在实现高效导热的同时，保持了较高的体积电阻率和介电强度，能够在 IGBT 模块的典型工作电压下构建稳定的电隔离层，从而确保运行安全。

(3) 匹配的热膨胀：其热膨胀系数（~4.5×10⁻⁶/K）接近硅芯片。在热循环过程中，它能有效降低热应力，防止焊层开裂，从而提高长期可靠性。

然而，仅拥有高性能陶瓷并不足以构建完整的模块。它还需要与金属结合才能实现导电和散热。

DBC 技术：从陶瓷到多功能基板

为了充分发挥 AlN 的材料优势，现代 IGBT 模块通常采用直接键合铜 (DBC) 技术。该工艺通过高温共晶反应，将高纯度铜箔牢固地粘合到氮化铝（AlN）陶瓷片的两侧，形成铜-陶瓷-铜的三明治结构。每一层都具有清晰且协调的功能：

– 上层铜层：作为电路层，用于焊接IGBT芯片并传导主电流。

– 中间层氮化铝陶瓷层：作为功能核心，兼具高效绝缘和快速导热功能。

– 下层铜层：作为传热层，将热量传递至金属基板和外部冷却系统。

– 通过这种结构，AlN-DBC基板不再是孤立的陶瓷，而是集导电、绝缘、导热和机械支撑于一体的多功能集成载体，为IGBT模块的高功率密度和高可靠性运行奠定了坚实的物理基础。

氮化铝（AlN）DBC 的核心使命

在 IGBT 模块中，AlN-DBC 决定了模块的性能极限：

(1) 热管理

高导热性使芯片产生的热量能够快速散发，确保模块在高电流和高功率密度条件下稳定运行，从而实现小型化和高效率。

(2) 电气绝缘

在高压芯片和接地散热器之间提供可靠的绝缘隔离，确保高压系统（例如汽车 800V 平台）的安全运行。

(3) 机械稳定性

热膨胀匹配降低热循环应力，确保模块在频繁启停、加速和高功率循环下的接口可靠性，从而显著延长其使用寿命。

因此，AlN-DBC 已成为电动汽车主驱动逆变器、车载充电器 (OBC)、大功率光伏/储能转换器、超快充电站和高端工业伺服驱动器等先进应用的首选解决方案。它为这些领域的性能突破提供了坚实的材料基础。

随着电力电子技术的发展，IGBT 模块正朝着更高功率、更小尺寸和更高可靠性的方向发展。AlN-DBC 衬底为这一趋势提供了关键支持，并为未来宽禁带半导体器件的高温应用奠定了基础。 Innovacera 可提供定制化的氮化铝 (AlN) 基板解决方案，帮助客户打造高性能、高可靠性的下一代功率模块。欢迎随时联系我们。

Behind the swift movement of electric vehicles, the operation of photovoltaic power stations, and the precise control of industrial production lines, there is a common core power component – the IGBT (Insulated Gate Bipolar Transistor) module. It converts direct current into alternating current, precisely regulates the motor speed and torque, efficiently controls power switches, and completes the conversion and regulation of electrical energy. It is the “heart” of power electronic devices.

As the industry continuously enhances the performance and efficiency of systems, IGBT modules are evolving towards higher power density, smaller size, and greater reliability to meet the demands of lightweighting in electric vehicles, high power output, efficient operation of new energy inverters, as well as long lifespan and high reliability of industrial frequency conversion equipment. In such applications with high power and high heat load, safely and efficiently discharging the heat generated by the chip has become a major challenge in module design.

This answer is largely hidden within a seemingly insignificant component of the module – the base plate. It is not an ordinary metal plate, but a precise component made of a copper-ceramic-copper composite structure. The substrate of IGBT modules has traditionally been made of ceramic materials. For low-power modules, aluminum oxide, which is cost-effective and has mature manufacturing processes, is commonly used. However, in high-power and high-reliability applications, aluminum nitride has emerged as the key material for modern IGBT substrates due to its high thermal conductivity and excellent insulation properties.

Why aluminum nitride?

Aluminum nitride is an advanced functional ceramic. It is used in high-performance IGBT modules due to its outstanding physical properties:

(1) Excellent thermal conductivity: The thermal conductivity is as high as 170–230 W/mK, which is 6–8 times that of traditional alumina, enabling the rapid transfer of heat generated by the chip to the base plate, thus preventing overheating and failure.

(2) Reliable insulation: While achieving efficient heat conduction, AlN maintains a high volume resistivity and dielectric strength, enabling the construction of a stable electrical isolation barrier at the typical operating voltage of IGBT modules, ensuring operational safety.

(3) Matching thermal expansion: Its thermal expansion coefficient (~4.5×10-6/K) is close to that of silicon chips. During thermal cycling, it effectively reduces thermal stress and prevents the cracking of the soldering layer, thereby enhancing long-term reliability.
However, merely having high-performance ceramics is not sufficient to construct a complete module. It needs to be combined with metals in order to conduct current and dissipate heat.

DBC Technology: From Ceramics to Multi-functional Substrates

In order to fully utilize the material advantages of AlN, modern IGBT modules typically employ the Direct Bonded Copper (DBC) technology. This process achieves the bonding of high-purity copper foil firmly to both sides of the AlN ceramic sheet through a high-temperature eutectic reaction, forming a sandwich structure of copper-ceramic-copper. Each layer has a clear and coordinated function:

-Upper copper layer: As the circuit layer, it is used for soldering IGBT chips and conducting the main current.

-The middle AlN ceramic layer: It is the functional core, achieving both efficient insulation and rapid heat conduction.

-Lower copper layer: As a heat transfer layer, it conveys heat to the metal base plate and the external cooling system.

Through this structure, the AlN-DBC substrate is no longer an isolated ceramic, but becomes a multifunctional integrated carrier that integrates conductivity, insulation, heat conduction and mechanical support, laying a solid physical foundation for the high power density and high reliability operation of IGBT modules.

The core mission of AlN-DBC

In the IGBT module, AlN-DBC determines the performance limit of the module:

(1) Thermal Management
The high thermal conductivity enables the heat generated by the chip to be quickly dissipated, ensuring the stable operation of the module under high current and high power density conditions, and achieving miniaturization and high efficiency.

(2) Electrical insulation
Provide reliable insulation isolation between high-voltage chips and the grounding heat sink to ensure the safe operation of the high-voltage system (such as the automotive 800V platform).

(3) Mechanical Stability
The thermal expansion matching reduces thermal cycling stress, ensuring the interface reliability of the module during frequent start-stop, acceleration, and high-power cycles, significantly extending its service life.

For this reason, AlN-DBC has become the preferred solution for advanced applications such as electric vehicle main drive inverters, on-board chargers (OBC), high-power photovoltaic/storage converters, ultra-fast charging stations, and high-end industrial servo drives. It provides a solid material foundation for performance breakthroughs in these fields.

With the development of power electronics technology, IGBT modules are evolving towards higher power, smaller size and greater reliability. The AlN-DBC substrate provides crucial support for this trend and lays the foundation for future high-temperature applications of wide bandgap semiconductor devices. Innovacera can offer customized solutions for Aluminum nitride (AlN) Substrates, helping customers create high-performance and reliable next-generation power modules. Please feel free to contact us.