Analysis of temperature curve of backweld furnace

Abstract

This paper mainly analyzes the temperature curve of PCB circuit board in soldering furnace, through the knowledge of heat transfer and change the temperature of each area and conveyor belt speed to study the change of temperature curve. Through the analysis, it is concluded that the circuit board transfer process is mainly heat convection and heat radiation. The ordinary differential equations based on heat convection and heat radiation are established between each temperature region and its gap. According to the law of energy conservation and the time of circuit board temperature field entering back welding furnace, the initial conditions are obtained. The temperature distribution in the center of the welding area at different time was obtained by using the improved Euler method. The ergodic search algorithm is used to search in a certain range, and finally according to the temperature process boundary, a better initial velocity condition is obtained through calculation and analysis. Add the ideal furnace temperature curve and the temperature in the center of the welding zone should not exceed 217 for too long, and the peak temperature should not be too high to minimize the area covered by the ideal furnace temperature zone over 217 to the peak temperature. Covariance analysis was conducted on the two sets of data values by taking a certain amount of equidistant discrete points of the temperature on the left and right sides of the peak temperature, so that the furnace temperature curves with the peak temperature as the center line exceeding 217 were as symmetrical as possible.