Integrated Circuit (Ic)-Embedded Wafer-Level Packaging Technology For Millimeter-Wave Power Ics

A wafer-level packaging (WLP) technology for millimeterwave power devices is presented, which features simple fabrication, low-signal transition loss, and thermal consideration. Instead of using a rigid interposer, the proposed WLP technology incorporates thick copper sheet and an adhesive tape as the initial carrier. Short electroplated interconnection showed transition loss within 0.2 dB and return loss above 20 dB, at frequency range up to 30 GHz. We demonstrate the WLP with an RF power amplifier at 28 GHz. The power-added efficiency (PAE) of the power amplifier packaged in the proposed technology is 30% at an output power of 27.5 dBm, which is identical to an unpackaged integrated circuit (IC) wire bonded on a printed circuit board. The size of the IC, and the final packaged sample was 2.2 x 1.5 x 0.1 mm(3) and 3.3 x 2.4 x 0.2 mm(3), respectively.