【摘要】 倒装焊器件底充胶的填充质量对于芯片可靠性的影响较大。超声扫描技术可以有效检测芯片与基板之间凸点周围的底充胶的填充质量。选用30 MHz和110 MHz频率的超声换能探头检测底充胶层,两种频率探头检测结果清晰度均能满足底充胶缺陷检测要求。结果显示,30 MHz探头聚焦范围宽于110 MHz探头,操作更为简便。对于包含热沉的器件,热沉的存在会干扰超声扫描显微镜对底充胶层的检测,未去除热沉可能导致研究者误判底充胶层填充情况,去除热沉后可获得底充胶层的清晰成像。倒装焊器件底充胶层厚度比较薄,检测时SAM的栅门宽度选取不易过宽,否则会影响图像清晰度,其具体值可视被测器件不同而调整。更多还原

【Abstract】 The effect of the underfill filled quality of flip chip on the chip reliability is remarkable.Filled quality of the underfill between die and substrate was detected by the ultrasonic scanning technique effectively. The underfill of flip chip was detected with 30 MHz and 110 MHz ultrasonic transducers,and the SAM images of both transducers were clear enough to detect the defects of the underfill. The results show that the 30 MHz transducer is wider focusing scope than 110 MHz transducer and it is able to meet a demand for bug examination of the underfill. For the flip chip with a heat sink,SAM detection of the underfill is affected. Moreover,SAM images obtained with heat sink remained can lead researchers to misunderstand the filled quality of the underfill. SAM images obtained with heat sink removed are clear. The underfill of flip chip is quite thin,thus setting the gate width of the SAM too wide is inappropriate in the test. And the gate width can be adapted with different flip chips.更多还原