Signal integrity and heat transfer performance of through-boron nitride via

Silicon interposer is widely used in 2.5D integrated packages due to its good dielectric properties and mature process. However, silicon interposer is not suitable for high-power devices and radio frequency devices, suffering from poor signal integrity and low thermal conduction efficiency. In this work, c-BN is used as an interposer to provide a solution for electrical signal interference and thermal aggregation in the devices. In addition, PTFE, glass and h-BN, w-BN have also been studied for comparison. The finite element simulation results show that the return loss of the TBV (c) is 3.3 dB lower than that of the TSV at 40 GHz. The insertion loss of TBV (c) is 0.12 dB higher than that of TSV. The c-BN interposer performs better than the silicon interposer in terms of signal integrity, with a similar performance to the glass interposer. The accuracy of the finite element simulation is verified by the RLGC analytical model. The return loss of TBV (c) decreases due to the decrease in the interposer thickness, the increase in spacing between the Cu pillars or the increase in radius of the Cu pillars. Owing to the high thermal conductivity of c-BN, the horizontal and the vertical equivalent thermal conductivity of TBV (c) are approximately 8 times than those of TSV. The heat dissipation performance of TBV (c) is also better than that of TSV. The TBV (c) interposer shows advantages in both electrical and heat transfer aspects, which provide new perspectives for device development in 2.5D integrated packages.