基于微电子封装焊点超声图像边缘效应分析的可靠性无损评价方法

A non-destructive evaluation approach to solder joint reliability in microelectronic packaging based on the analysis of edge effects in ultrasonic images

封装技术的集成化与小型化对封装内部焊点的无损评价方法提出了更高的要求。为研究微电子封装中焊点的可靠性问题,提出了一种基于微电子封装焊点超声图像边缘效应分析的可靠性无损评价方法。首先,设计并制造了装载有倒装芯片封装的试验样板,并利用热循环加速试验对样板进行老化处理。每4个试验周期,样板取出进行超声数据采集以监测焊点退化。其次,通过有限元仿真深入研究了超声波在电子封装内部的传播机制,建立了焊点超声图像几何特征与焊点实际物理特征之间的定性定量关系。在该理论基础上,提出一种焊点超声图像边缘提取算法,优化了焊点超声图像中心区域的定位。最后,通过焊点图像中心区域的亮度变化,确定了不同位置焊点的失效周期。利用均方根误差作为评价指标,将研究结果与以往方法进行了对比。结果表明:所提出的边缘检测算法在处理低质量焊点图像时,表现出显著的优势,具有良好的抗噪性能,能够得到清晰的单像素边缘;在焊点可靠性评价中,相较于以往的方法,均方根误差从137.11增强至41.23,检测精度提高了69.96%,大幅提升了焊点可靠性评价的准确性。这为微电子封装焊点的无损评价提供了有力的理论支持。

The integration and miniaturization of electronic packaging technology have set higher standards for the non-destructive evaluation methods of internal solder joints within the packaging.To address the reliability of solder joints in microelectronic packaging,a reliability non-destructive evaluation method based on ultrasonic image edge effect analysis of microelectronic packaging solder joints was proposed.Initially,the test boards loaded with flip-chip packaging was designed and aged using accelerated thermal cycling test.Solder joint degradation was regularly monitored by taking out the test boards from the temperature chamber for ultrasound data acquisition at every four test cycles.Subsequently,an in-depth study of the propagation mechanism of ultrasonic waves within electronic packaging was conducted using finite element simulation,establishing a qualitative and quantitative relationship between the geometric features of solder joint ultrasonic images and the actual physical characteristics of the solder joints.On the basis of this theory,an edge extraction algorithm for solder joint ultrasonic image was proposed,optimizing the positioning of the central area in the solder joint ultrasonic images.Ultimately,the failure period of solder joints at different positions was determined by the brightness change of the central area of the solder joint image.Using the root mean square error as an evaluation indicator,the results of this study were compared with those from previous research.The results demonstrate that the proposed edge detection algorithm exhibits significant advantages in handling low-quality solder joint images,has good anti-noise performance,and can obtain clear single-pixel edges.In terms of solder joint reliability assessment,compared to previous methods,the root mean square error was enhanced from 137.11 to 41.23,and the accuracy of detection was improved by 69.96%,significantly increasing the accuracy of solder joint reliability assessment.This provides a solid theoretical basis for non-destructive evaluation of solder joints in microelectronic packaging.