基于Transient Thermal的回流焊温度曲线仿真技术研究

Study on the Simulation Technology of Reflow Soldering Temperature Profile Based on Transient Thermal

摘要: 回流焊工艺是表面组装技术SMT的重要一环，决定了电子器件焊接的质量与速度。作为回流焊工艺重要环节，回流焊温度曲线直接影响PCB板的质量。本文针对某回焊炉，通过热传导模型求解出稳定工作时炉内温度曲线，建立了基于Transient Thermal的回流焊温度曲线仿真模型，优化包括温区温度设定以及传送带速度的因素。根据得到的仿真实验数据，通过逐步回归，分析出制程界限与各因素的关系，在制程界限下通过仿真建模，求解出最优的回流温度曲线。最后求出传送带速度为82.44 cm/s，五大温区温度设置分别为165℃、185℃、225℃、265℃、25℃，进一步优化了回流焊温度曲线。对比传统的反复实验调整，基于Transient Thermal的仿真建模方法可以在更高效率下得到更精确地优化控制。该方法能以其高效率与低能耗的优势，更好为回焊炉参数设置提供决策支持。

Abstract: The reflow soldering process is an important part of the surface assembly technology SMT, which determines the quality and speed of soldering of electronic devices. As an important part of the re-flow soldering process, the reflow soldering temperature profile directly affects the quality of the PCB board. In this paper, for a certain reflow furnace, the temperature curve in the furnace during stable operation is solved through a heat conduction model, and a simulation model of the reflow soldering temperature curve based on Transient Thermal is established to optimize factors in-cluding temperature zone temperature setting and conveyor belt speed. According to the obtained simulation experiment data, the relationship between the process limit and various factors is an-alyzed through stepwise regression, and the optimal reflow soldering temperature curve is solved through simulation modeling under the process limit. Finally, the speed of the conveyor belt is 82.44 cm/s, and the temperature settings of the five temperature zones are respectively 165˚C, 185˚C, 225˚C, 265˚C, 25˚C, which further optimizes the reflow soldering temperature curve. Com-pared with the traditional repeated experiment and adjustment, the simulation modeling method based on Transient Thermal can get more precise optimized control with higher efficiency. This method can better provide decision support for the parameter setting of the reflow furnace with its advantages of high efficiency and low energy consumption.