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针对实际服役条件下电路板级焊点失效引起的电子设备故障问题,基于单一时间因子传递熵方法,建立了振动与温度耦合条件下的焊点非经验疲劳寿命模型.首先,通过分析焊点裂纹萌生前后的能量变化,构建了能够表征焊点结构损伤的平均能量测度指标.其次,根据该指标在焊点微裂纹出现前呈现出的单调性特点,建立了用以评估焊点疲劳寿命的公式.最后,设计振动与温度耦合条件下的焊点加速寿命试验,基于实时获取的焊点结构动态响应信号,验证该模型的准确性与适用性.试验结果显示,该模型能够有效识别焊点的损伤状态,疲劳寿命预测结果误差在1 5%以内.
Aiming at the problem of electronic equipment failure caused by the failure of circuit board level solder joint under actual service conditions, a non-empirical fatigue life model of solder joint under vibration and temperature coupling conditions is established based on the single-time factor transfer entropy method.Firstly, According to the monotonic characteristic of the index before the micro-cracks appear, a formula to evaluate the fatigue life of the solder joint is established .Finally, the accelerated life test of the solder joints under the condition of vibration and temperature coupling is designed, and the accuracy and applicability of the model are verified based on the real-time dynamic response signals of the solder joint structure.The experimental results show that the model can effectively identify the solder joints Damage state, fatigue life prediction error of less than 15%.