Development of low cost through glass via (TGV) interposer with high-Q inductor and MIM capacitor

Due to low dielectric loss, high insulation property and low cost, glass is regarded as a promising material for advanced 2.5D interposers. In this paper, through glass via (TGV) interposer with high quality factor (high-Q) and MIM capacitors is studied. Low-cost laser induced deep etching (LIDE) technology is applied for the formation of TGVs. Then TGVs are used to implement inductor with minimal footprint and high-Q. Based on the physical structure and the basic parameters of the TGV inductor, the Q value and the inductance value can be calculated with High Frequency Structure Simulator (HFSS). The simulation results represent that the Q value and inductance of the designed TGV inductor at 6GHz is about 55 and 1.73nH respectively. Moreover, the impact of redistribution line (RDL) width on quality factor value and inductance value of TGV inductor is studied. It is found that when the RDL width increases from 60μm to 80μm, the Q value changes slightly at 100MHz, and increases by 10% at 2GHz, and 12% at 5GHz. As a contrast, the inductance remains unchanged. Finally, metal-insulator-metal (MIM) capacitor with a value of 0.28pF was designed and fabricated on the top of the TGV interposer.