Development of SOP Module Technology Based on LCP Substrate for High Frequency Electronics Applications

Liquid crystal polymer (LCP) materials are considered to be promising substrates for RF-applications. In this work, the high frequency characteristics of LCP were investigated using a microstrip ring resonator. The purpose is to verify the possibility of the application of the material in RF packaging. The metallization of LCP was studied for the purpose of board fabrication. The adhesions between deposited copper and LCP layer were also measured by the shear-off-method. The standard planar fabrication techniques were employed to complete the LCP based substrate and a multi-staged fabrication flow for LCP substrate has been optimized. Furthermore, flip chip (FC) bonding was carried out to bond a daisy chain chip onto the LCP substrate by using anisotropic conductive films (ACF), and the functionality was tested by the four point resistance measurements. The results indicate that LCP has a dielectric constant of about 3 and a loss tangent of about 3.5times10^-3 in the frequency range between 2 and 35 GHz. Flip-Chip bonding of ACA joint on LCP substrate shows a resistance of about 0.7 Ohm. Finally, embedded technique of active devices into the LCP substrate has been demonstrated