Thermally Induced Losses on High Speed Interconnects

• Published in: 2023 IEEE Symposium on Electromagnetic Compatibility & Signal/Power Integrity (EMC+SIPI) pp. 153 - 157
• Main Authors: Luevano, Gerardo Romo, Ferguson, Chris, Ochoa, Ennai, Randhawa, Harpreet
• Format: Conference Proceeding
• Language: English
• Published: IEEE 29.07.2023
• Subjects: Dielectric losses; high-speed interconnects; Metals; Signal integrity; Stripline; Systematics; Temperature dependence; Temperature distribution; Temperature measurement; thermally induced losses
• DOI: 10.1109/EMCSIPI50001.2023.10241756

This paper presents a systematic approach for broadband characterization of thermally induced losses on high-speed interconnects. The characterization relies on S-parameter measurements of striplines fabricated on a commercial board with 20GHz bandwidth. The measurements cover a temperature range from 0 to 100 degrees Celsius \left({ }^{\circ} \mathrm{C}\right), taken at 20-degree steps. For each temperature the high-speed interconnects are characterized from two-line measurements, which yields the complex-valued propagation constant at every temperature. As it is well-known, the real part of the propagation constant contains the loss information about the interconnects. By using the losses associated with the propagation constant at \mathrm{T}=0{ }^{\circ} \mathrm{C} as a reference, the thermally induced losses for all other temperatures are extracted. The thermally induced losses are then analyzed to determine the contribution from both the metal and the dielectric. Our results show that both the metal and the dielectric contribute to the thermally induced losses, but that the main contribution is primarily associated with the dielectric. From that, accurate temperature dependent models for the loss tangent Tanδ(T) and for the metal's resistivity can be defined from the measured data. It follows that the thermally induced losses due to the dielectric and the metal can be easily modelled in commercial EDA software by simply correcting the loss tangent and resistivity values for the desired temperature.