Quantifying the Effect of Thermal Contact Resistance on CPU Peak Temperature in a Laptop: A Steady-State Conduction Study

Thermal contact resistance (TCR) at the CPU–heatsink interfaces can dominate the thermal margins of laptop assemblies; therefore, this study quantifies the impact of TCR on CPU peak temperature (Tmax) and hotspot behavior under steady operating conditions. A steady-state, solid-only heat-conduction model is solved with internal heat generation (CPU and battery) and convective boundary conditions applied to the external enclosure surfaces. Under perfect contact (TCR = 0 m²KW-1), the predicted CPU Tmax is 71.4 °C, whereas introducing a realistic interface resistance of 5 × 10⁻⁵ m²KW-1increases CPU Tmax to 105.6 °C (ΔT = 34.2 °C, ≈ 48%), while the maximum enclosure surface temperature remains around 66.6 °C and the total convective heat rejection is 54.945 W. These results highlight that controlling TCR through appropriate thermal interface materials (TIMs) and assembly pressure is critical for reliable laptop thermal management.