In order to meet the requirements of miniaturization and lightweight development of Transmitter/Receiver(T/R) module in active phased array radar, a novel vertical interconnection structure is proposed in this paper. Semi-embedded Ball Grid Array(BGA) vertical interconnection structure is designed by using electromagnetic simulation software HFSS from the point of view of process optimization, combined with the characteristics of Low Temperature Co-fired Ceramic(LTCC) substrate. In addition, the influence of semi-embedded structure on vertical interconnection transmission performance is analyzed. The results show that the return loss is higher than 24 dB and the insertion loss is lower than 0.15 dB in X-band and 20 dB,0.6 dB in Ku-band. The semi-embedded structure can achieve good microwave transmission performance in a wide band between X-Ku band while optimizing the process.