Fully Embedded High Q Passives and Band Pass Filters for Low Cost Organic RF SOP (System on Package) Applications

In this paper, fully embedded high Q spiral inductors, MIM capacitor, 2.4 GHz WLAN BPF and wide-band pass filter are investigated into a multi-layered organic package substrate for low cost RF SOP (system on package) applications. These embedded passive components and filters were designed by using 3D EM simulators for finding out optimal geometries and verifying their applicability. An embedded circular spiral stacked inductor has inductance of 8.38 nH and maximum quality factor of 73 at 1.5 GHz, which is much higher than conventional film type chip ones. An embedded MIM capacitor has capacitance of 3.8 pF and maximum quality factor of 39.2 at 950 MHz. A folly embedded 2.4 GHz WLAN BPF has a size of 2.7 mm times 2.1 mm times 0.77 mm. It exhibits an insertion loss of -2.7 dB and return loss of -12.5 dB. WBPF is the first embedded and the smallest one of the filters formed onto the organic package substrate. It has a size of 3.2 mm times 2.5 mm times 0.77 mm. It exhibits an insertion loss of -2.65 dB, and an ultra-band width of 1.1 GHz, and a center frequency of 2.1 GHz. The measured performance characteristics of the embedded passive components and filters are well matched with the simulated ones.