Thermal Effects During Infrared Solder Reflow—Part II: A Model of the Reflow Process

Abstract

A numerical model is developed that describes the infrared reflow soldering of surface mounted components onto prewired circuit cards. The model predicts convective conditions within the reflow oven and uses these conditions, in conjunction with a radiative heat transfer analysis and a two-dimensional transient conduction analysis, to predict the thermal response of a card assembly as its components are soldered. The model is described, and its performance is illustrated through presentation of base case simulations. Parametric simulations are performed to determine the sensitivity of the card assembly thermal response to variations in oven conditions and uncertainties in the convective, as well as radiative heat transfer portions of the model.