In modern integrated circuit (IC) packaging, it is difficult to perceive and evaluate the quality of the solder ball interconnections due to their complex hidden physical configuration and miniaturization. Laser ultrasonic inspection (LUI) technique is a novel, nondestructive, and noncontact method that has achieved great success in evaluating the quality of interconnections in chip-scale and ball-grid array (BGA) packages. In this article, an enhanced dual-fiber array LUI system is used to evaluate the quality of BGA solder balls in advanced industrial flip-chip BGA packages subjected to thermal cycling reliability tests. LUI results are validated with electrical testing, scanning electron microscope (SEM), and dye-and-pry results. LUI results are well correlated with the intermetallic compound cracks in BGA solder balls observed using SEM, and dye-and-pry. This study demonstrates the feasibility of using the LUI system for one of the modern IC packages and the potential to use the LUI system for future advanced IC packages such as 3-D packaging.

中文翻译：

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使用激光超声检查技术评估经过热循环可靠性测试的FCBGA封装中BGA焊球的质量

在现代集成电路（IC）封装中，由于其复杂的隐藏物理配置和小型化，难以感知和评估焊球互连的质量。激光超声检查（LUI）技术是一种新颖，无损，无接触的方法，在评估芯片级和球栅阵列（BGA）封装的互连质量方面取得了巨大的成功。在本文中，增强型双光纤阵列LUI系统用于评估经过热循环可靠性测试的高级工业倒装芯片BGA封装中BGA焊球的质量。LUI结果通过电气测试，扫描电子显微镜（SEM）和染色和撬动结果进行验证。LUI结果与使用SEM观察到的BGA焊球中的金属间化合物裂纹密切相关，和染色和撬动。这项研究证明了将LUI系统用于一种现代IC封装的可行性，以及将LUI系统用于未来的高级IC封装（如3-D封装）的潜力。