High Inductance Density Glass Embedded Inductors for 3-D Integration

Abstract

Compared with silicon-based inductors, the inductors with through glass via (TGV) technology have significantly improved in quality ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q)$</tex-math> </inline-formula> factor. On the basis of TGV technology, a new type of 3-D embedded inductor is designed for the application scenarios with high inductance density. Through this research, a new preparation process is proposed to reduce the diameter of glass porous. On the basis of fully metallizing the glass porous, larger inductance density is achieved. The fabrication procedure requires grooving inside the glass substrate. In order to ensure the normal metal wiring on the surface, the cavity is filled with organic matter. Finally, the high-density, small-porous inductor array achieves an inductance density of 67.9 nH/mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{2}$</tex-math> </inline-formula> , which is three times higher than the previous glass inductance density. At the same time, the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Q$</tex-math> </inline-formula> factor is 49 and the self-resonance frequency (SRF) is 5.6 GHz.