金刚石在GaN功率放大器热设计中的应用

Application of Diamond in GaN Power Amplifier Thermal Design

随着GaN功率放大器向小型化、大功率发展,其热耗不断增加,散热问题已成为制约功率器件性能提升的重要因素。金刚石热导率高达2 000 W/(m·K),是一种极具竞争力的新型散热材料,可用作大功率器件的封装载片。采用不同载片材料对一款热耗为53 W的GaN功率放大器进行封装。分别采用有限元仿真及红外热成像仪对放大器的芯片结温进行仿真和测试,结果显示,采用金刚石载片封装的放大器的结温比采用钼铜(MoCu30)载片封装的放大器的结温降低了30.01℃,约18.69%。同其他常用载片材料进行进一步对比得出,在相同工作条件下,采用金刚石载片封装的放大器结温最低,并且随着热耗增加,金刚石的散热能力更为突出。在芯片安全工作温度175℃以下,金刚石能满足GaN功率放大器100 W热耗的散热需求。

With the development of GaN power amplifier to miniaturization and high power, the heat consumption is increasing, and the heat dissipation problem has become an important factor restricting the performance improvement of power devices.The thermal conductivity of diamond is up to 2 000 W/(m·K),which is a competitive heat dissipation material and can be used as the package carrier of high-power devices.A GaN power amplifier with a heat consumption of 53 W was packaged with different carrier materials.Finite element simulation and infrared thermography instrument were used to simulate and test the chip junction temperature of the amplifier, respectively.The results show that the junction temperature of the amplifier packaged with diamond carrier is 30.01 ℃ lower than that of the amplifier packaged with MoCu30 carrier, about 18.69%.Further comparison with other common carrier materials shows that, under the same working condition, the junction temperature of the amplifier packaged with diamond is the lowest.Meanwhile, with the increase of heat consumption, heat dissipation capability of diamond becomes more and more prominent.Below the chip safe working temperature of 175 ℃,diamond can meet the heat dissipation requirements of 100 W heat consumption of the GaN power amplifier.