Non-Fourier heat conduction in IC chip

The authors address heat conduction in an IC chip with special attention paid to the evaluation of the non-Fourier effect and its importance for the thermal analysis and design of an IC chip. Instead of the classic Fourier equation based on the diffusion mechanism, a finite-speed propagation model in a spherical system expressed in a hyperbolic equation is used to predict the transient process of heat conduction, when a heat source with a square-corner switching wave form is applied. The peak temperature, spatial difference, and time variation of temperature which are critical to the thermal reliability of the chip are given and compared with that obtained from the Fourier equation. Analytical and numerical results show that non-Fourier effects covering the higher peak temperature and thermal stresses, a larger temperature difference between components, and stronger thermal noises are significant to IC chip reliability. It is suggested that if the product or shift frequency and the relaxation time of the medium exceeds 0.1 it is necessary to take non-Fourier effects into consideration.<>