倒装陶瓷球栅阵列电子封装的热分析

Thermal Analysis of Flip Chip Ceramic Ball Grid Array Package

建立了倒装陶瓷球栅阵列(flip chip ceramic ball grid array,FC-CBGA)封装的三维热模型。在5 W热负荷下,比较了裸芯片式、盖板式和盖板加装热沉三种情况下芯片的热性能,进而分析了有无热沉和不同空气流速下,盖板式封装的具体热流分配情况。结果表明:在自然对流下,与裸芯片式相比,采用盖板式能使芯片结点温度降低约16℃,盖板加装热沉能使芯片结温降低47℃。芯片产生的热量大部分向上流向盖板,且随着空气流速的增加比例增大;由芯片流向盖板的热量有相当大一部分经过侧面流向基板,且随着流速增大比例较小。

The three-dimensional model of flip chip ceramic ball grid array （FC-CBGA） was set up and simulated. With 5 W heat load, three types of bare die, metal cap and metal cap with sink influencing on thermal performance were compared in detail. And then the distribution of heat flux for metal cap package with and without sink in different air velocities was discussed. The results show that the junction temperature of die can be reduced about 16 ℃ and 47 ℃, comparing metal cap and metal cap with sink with bare die in the natural convection, respectively. Most of heat flux generated by the die flew up to the metal cap, and rose up with the increase of the air velocity. A considerable portion of the heat flux from the die to the cap flew to the substrate through the sides of cap, and decreased as the air velocity increased.