Thermal model of buried resistors and design guidelines for buried components

摘要

The results of a detailed thermal model of the temperature rise in printed circuit boards and chip carriers. The model is a conjugate model representing conduction in the board, convection in the surrounding air, and radiation from the board. An experimental study is conducted to verify the modeling results, and excellent agreement is found for a wide range of power dissipation levels. The model is then used to conduct a comprehensive parametric study of the effects of air flow velocity in the surrounding air, the effect of buried component spacing and size, the effect of card thickness, and the effect of power planes and their distance from the buried components. This modeling methodology represents an accurate and simple way to develop and utilize design ground rules for buried components. Decisions on size, power dissipation levels and operating temperatures can be made in predictive manner.