A technique for interconnecting millimeter wave integrated circuits using BCB and bump bonds

A low cost interconnection scheme for millimeter wave modules is presented. This technique allows the integration of hybrid components using an inexpensive micromachined silicon motherboard and benzocyclobutene (BCB) films. The excellent planarity of BCB allows vias to be formed using bumps fabricated prior to BCB application. This approach eliminates the need for laser drilling, plasma etching, and plated holes. Several representative GaAs pHEMT's were packaged using this technique. Measurements show minimal performance degradation from 1 GHz to 48 GHz.