摘要:
借助有限元法分析了锑化铟红外探测器铟球焊点的可靠性.结果表明,应力最大值位于探测器边缘拐角处锑化铟芯片与铟球连接处,且在周期性温度载荷下,应力呈周期性变化.温度降低,应力迅速升高,降到77 K时达到最大值,保温阶段存在应力松弛现象,温度升高应力值大幅度降低.随着铟球直径的增加应力最大值不呈现出明显的变化规律性,但塑性功逐渐减小塑性能量累积也缓慢降低,表明随着铟球直径的增加,红外探测器的可靠性越高.当铟球直径取30μm时,整个红外探测器不同材料接触面上的应力分布呈现集中性、均匀性,整体应力最小.
关键词:
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倒装焊
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有限元法
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粘塑性
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应力集中
Abstract:
Based on viscoplastic model,the reliability of indium sphere soldered joint in infrared focal plane array detector was analyzed by finite element method.Simulation results show that the maximum equivalent stress appears on the contact area between InSb chip and indium sphere,which is located in the corner of indium sphere array and far away from the symmetric center of the detector.When the infrared detector was loaded periodically with temperature cycles,the maximal stress also varied periodically.As the temperature decreases from the room temperature to 77 K,the maximal stress increases rapidly to the maximum value,and during the holding time,the stress relaxation phenomena appears,and as the temperature increases,the maximal stress reduces sharply.As the diameter of the indium sphere increases,the maximum stress varies irregularly,while the plastic energy analysis results show that as the diameters of indium sphere increase,its plastic work decreases,and its plastic energy accumulation also reduces,which indicates that the structure with larger diameter has the higher fatigue reliability.It is noticed that when the diameter of the indium solder is set to be 30 μm,the stress distribution on all the contacting areas is uniform and concentrated,and the stress is the lowest.
百度学术
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