Double-sided Si-interposer with embedded thin film devices

In this paper, a low-cost interposer technology is introduced which is a combination of PCB laminations and semiconductor thin-film processes. In advance, thin-film MIM capacitors are realized on the silicon surface by using standard thin-film process. After then, organic lamination and laser via drilling processes are used to make multi-layer signal and interconnections. Due to dual-side lamination process, the interposer has a symmetric structure and there are no warpages as increment of the number of signal layers. The fabricated interposer has an only 240 μm thickness and it has more than 8 metal layers. To demonstrate the interposer technology, a RF FEM is designed and realized by using the technology. In this module, thin film IPDs (Integrated Passive Devices) such as 2.45 GHz BPF and Balun are integrated in the front-side of the interposer, and a SPDT switch and 0603 chip capacitors are mounted on the back-side of the interposer.