Patterned Multi-Material Die Attach Process Using Aerosol-Jet Printing

Advancements in additive manufacturing techniques provide attractive options for RF systems fabrication and development, particularly with respect to heterogeneous integration of bare die components. To facilitate the inclusion of these parts, a new Aerosol-Jet Printed (AJP) die attach method utilizing a patterned combination of adhesive and conductive inks is demonstrated to improve chip leveling and CTE match with die fill materials. In this paper, a patterned combination of printed Benzocyclobutene (BCB) and silver nanoparticle inks are investigated as the primary adhesive and conductive materials respectively. Several dies are tested using this attach method, including S-parameter measurements from attenuator dies with less than 2 dB loss in the 0-20 GHz frequency range. Finally, a Ku-band transmit module where all die level components utilize the proposed attach method is demonstrated, producing more than 34 dBm output power from 13 to 17 GHz.