基于数值模拟方法的虚焊焊点热传导影响因素分析

针对现有的常用焊接质量检测技术无法有效检测的电子产品虚焊类缺陷问题，采用数值模拟方法对虚焊焊点红外热像检测过程进行分析，详细讨论其瞬态传热问题，并深入分析虚焊程度、热流密度、激励位置以及焊接参数不同而造成的焊点形状差异等因素与焊点表面温度信息参数之间的关系。结果表明:虚焊程度40%以下的焊点热幅值差异较小，难以辨识；热流密度越高，信噪比越高，焊点虚焊检测可靠性越高；不同激励位置的虚焊缺陷温差达到0.36 ℃，影响较大；焊点尺寸对于虚焊温差影响较小。

Analysis of Heat Conduction Influences Factors of Pseudo Soldering Based on Numerical Simulation

Aiming at the problem of pseudo soldering defects in the electronic products that cannot be effectively detected by the existing welding quality detection technology, the virtual joint process of infrared thermal image detection is analyzed by using numerical simulation method, and the transient heat transmission was detailed discussed, and the relationship between the solder surface temperature and the factors, such as pseudo soldering degree, heat flux density, solder volume and heat stimulation position on the detectable signals, are analyzed. The simulation results showed that the difference of the heat amplitude of the welding spot with the virtual welding degree below 40% is small, which is difficult to identify; the higher the heat flux density is, the higher the SNR is, and the higher the reliability of spot virtual welding detection is; the temperature difference of virtual welding defects at different excitation positions reached 0.36 ℃, which had a great influence. The solder joint size has little influence on the temperature difference of virtual welding.