A Vertical Transmission Leadless Surface-mountable Ceramic Package with High Core Proportion

This paper presents a 40GHz vertical transmission leadless surface-mountable ceramic package with high core proportion, realized in high temperature co-fired ceramics (HTCC) technologies. The RF transmission terminal of the package adopt vertical hollow via transmission, which can improve the core proportion. Compared with solid transmission, core area can be increased by 25%. The RF transmission structure includes ground coplanar waveguide line-hollow via-ground coplanar waveguide line. By optimizing the discontinuous structures, the application frequency of the package can reach 40GHz, and the board level measurement insertion loss of two ports is less than 1.5dB. At the same time, the package has passed the environmental and mechanical tests. In addition, when the package is applied in the system, it needs to be attached to the PCB. Due to the large difference in thermal expansion coefficient between ceramics and PCB, the reliability risk of board-level installation caused by thermal mismatch between materials is analyzed. And the board level installation was verified without failure. The package shows excellent high frequency transmission characteristics and high reliability.