Three-dimensional Package Design Of K-band Amplifier Based On LTCC/BCB

Due to limitations in size,weight,and power,active phased array antennas that traditionally use "brick" components are inadequate for applications such as helicopters,drones,seekers,and small satellites.The transceiver component is the core component of the active phased array antenna.The choice of its architecture largely determines the layout of the phased array antenna and is an important factor affecting the weight and size of the antenna.Compared with the traditional "brick" components using planar integration,the three-dimensional integrated circuit with vertical interconnect structure has an unparalleled advantage in miniaturization.It is of great significance to study the miniaturization of transceiver components by studying the three-dimensional integrated package design of the amplifier.LTCC(Low Temperature Cofire Ceramic)technology has three-dimensional wiring,passive components can be embedded in the inner layer of the substrate,and can be reserved for cavity embedding.It is favored in the three-dimensional integrated design of microwave circuits..However,due to the use of a thick film process to achieve printed graphics,the consistency of electrical performance in the millimeter wave band is insufficient.BCB(Benzocyclobutene,benzocyclobutene),due to its low dielectric constant and low dielectric loss,enables high-precision wiring using a thin-film process and has advantages in the millimeter-wave band.The combination of LTCC and BCB has complementary advantages,which provides the possibility to further improve the three-dimensional integration performance of the millimeter wave amplifier.This paper starts with the theory of microwave transmission,and studies the structure and vertical interconnection structure of LTCC transmission line.The thick film hybrid substrate based on LTCC and BCB is explored.The vertical interconnect structure embedded in the air cavity structure is proposed,which suppresses the parasitic capacitance and effectively reduces the transmission loss of the vertical interconnect structure in the millimeter wave band.In order to explore the details and limits of BCB film process and the characteristics of BCB through-hole,a silicon-based vertical interconnect structure BCB splitter that can work in Ka-band is designed and processed,and combined with process processing,suggestions for future BCB through-hole design are proposed.Based on the mastery of LTCC and BCB vertical interconnect structure modeling and process,the K-band amplifier is designed for three-dimensional packaging and miniaturization.The power amplifier and low noise amplifier and the corresponding control circuit are designed in a three-dimensional package,and the volume is reduced by more than 30%compared with the conventional planar package structure.According to the characteristics of thick film and thin substrate,the embedded chip is rewiring design using micro bump technology.The vertical interconnection structure is used to realize the inter-board interconnection of microwave signals.The interlayer interconnection of RF signals and electrical signals is realized by BGA technology,and the overall model is simulated and optimized by the method of joint simulation design.In order to facilitate the test,the test board was designed and fabricated separately,and finally the assembled modules were assembled and tested,and good test results were obtained.