Modeling of the RF Coaxial TSV Configuration Inside the Silicon Interposer With Embedded Cooling Cavity

Abstract

In this article, a low-loss RF coaxial through-silicon vias (TSVs) (C-TSVs) configuration in the silicon interposer with the embedded cooling cavity is proposed. For the single C-TSV array passing through the embedded cooling cavity, the transmission losses with different coolants were compared. The insertion loss immersed in FC770 is 0.14 dB at 40 GHz, which is closed to the typical C-TSV interposer (0.2 dB). It is much smaller than the deionized water (6.49 dB) one. The optimal spacing of multiple C-TSV arrays filled with FC770 coolant is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$600~\mu \text{m}$ </tex-math></inline-formula> (vertical transmission of 0.16 dB at 40 GHz). When the cooling cavity is embedded in the interposer with FC770 coolant, the maximum surface temperature of the power devices can be less than 56.8 °C at 250 W/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> heat flux. Compared with the solid silicon interposer, the maximum von Mises thermal stress of the C-TSV interposer with the embedded cooling cavity can be reduced by 44.8%.