Selectively anodized aluminum substrates for microwave power module package

In this paper, we present a selectively anodized aluminum substrate for microwave power module package. High performance passive components are integrated on thick anodized aluminum oxide (Al₂O₃) layer and power chips are mounted on aluminum with the ability of effective heat sink. To investigate the performance of passive components integrated on anodized aluminum substrate at high frequency, coplanar waveguides (CPWs) was fabricated on the substrate. The fabricated CPW showed lower insertion loss than 0.17 dB/mm up to 18 GHz. Using copper (Cu) electroplating and BCB dielectric, high-Q inductors were integrated on anodized aluminum substrate. The fabricated planar spiral inductor with 1nH inductance showed the maximum quality (Q) factor of 56 at 5.5 GHz.