Work

Electro-Thermal Co-Design and Verification of TGV Transmission Structures for High-Power High-Frequency Applications

Year: 2026

Type: article

Abstract: Through Glass Via (TGV) technology has become an emerging technology in the field of advanced packaging. Compared to silicon materials, glass exhibits lower dielectric loss. However, its thermal conductivity is two orders of magnitude lower than silicon, potentially causing transmission performance degradation due to electro-thermal coupling effects in high-power, high-frequency application. Therefore, this study present by conducting electro-thermal co-design of TGV grounded Coplanar Waveguide (CPW), TGV based Substrate Integrated Waveguide (SIW) structures, and RF TGV connected CPW structures. Samples of these TGV based transmission structures were fabricated and characterized. Under 6.3 W@ 18 GHz input conditions, the CPW, SIW, and quad-redundant RF TGV connected CPW structures exhibit insertion losses of 0.12 dB, 2.31 dB, and 1.12 dB, with corresponding temperature of 45.8 °C, 33.2 °C, and 41.4 °C, respectively. This study develops an electrothermal coupling simulation model to verify the experiments results. And the dependence of surface impedance on frequency and temperature was theoretically derived. Closed-form analytical formulas are derived to characterize the self-heating thermal resistance and temperature rise of CPW, SIW, and TGV structures. The relationship between the attenuation coefficient and thermal resistance was analyzed, theoretically explaining the reason of temperature differences between input and output ports in CPW, SIW, and RF TGV connected CPW structures. Under 20 GHz continuous wave input conditions, as the power increased from 5 W to 20 W, the maximum temperature of the TGV connected CPW structure rose from 36.1 °C to 128.5 °C, while the insertion loss only increased from 1 dB to 1.4 dB, demonstrating the structure's good high-power transmission capability and stable insertion loss across a wide temperature range. Compared to microstrip lines based on Rogers 5800 substrates, the structure achieves one-third the width with only a 12.5% increase in maximum temperature rise. Under 20 GHz pulsed wave input conditions, as power increased from 25 W to 100 W, the maximum temperature of the TGV connected CPW structure rose from 28.5 °C to 30.6 °C, while insertion loss only increased from 0.8 dB to 1.1 dB. This confirms that the structure possesses good high-power operational stability, providing an effective technical solution for high-power high-frequency applications.

Source: Micromachines

DOI: 10.3390/mi17020253