Current carrying capacity of copper conductors in printed wiring boards

Abstract

The effect of thermal management of the copper conductors on PWBs (printed wiring boards) having different dimensions and arrangements is discussed. Design charts have been generated to include the parameters of conductor thickness from 1 to 3 oz, width from 5 to 20 mils, spacing at 8 mils, board thickness from 31 to 62 mils, input current, and temperature rise up to 50/spl deg/C. The analysis is based on finite element modeling with a heat transfer film coefficient obtained from infrared thermal imaging analysis of a test board. Of all the geometric parameters considered, conductor width and spacing are the primary parameters influencing thermal resistance. Conductor thickness is next, and board thickness proves to be the least sensitive parameter.<>