Study on slit pad structure to maintain MMIC characteristics both in on-wafer and on-package conditions in millimeter-wave applications

Slit pad structure has been suggested as a novel probing/bonding pad in order to achieve the same characteristics for MMIC between on-wafer and on-package cases in millimeter-wave applications. The dimensions for the new structure has been estimated with measurement for transmission lines and calculations using a commercial EM simulator (Sonnet EM), while a bonding strength for wire on the slit pad has been confirmed experimentally using wire pulling and pushing tests. As a result, it has become clear that a slit width of 5 /spl mu/m and a gap, which is a distance between a GND pad and a land pad, of 40 /spl mu/m are the most adequate dimensions to maintain MMIC characteristics both in on-wafer and on-package in broad frequency range. In addition, it has been demonstrated that the slit pad having the slit width of 5 /spl mu/m has maintained the same strength for wire bonding compared with wire bonding on a pad without the slit.