Detection of solder joint degradation using RF impedance analysis
Detection of solder joint degradation using RF impedance analysis
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使用射频阻抗分析检测焊点退化
DOI：
10.1109/ectc.2008.4550035
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Pecht
中科院分区：
文献类型：
--
作者：
Daeil Kwon;M. Azarian;M. Pecht
许多类型的电子产品的趋势是朝向更高的工作频率或数字比特率。在高频下，信号传播集中在互连的表面，这种现象称为趋肤效应。互连的退化，例如由于疲劳或冲击载荷导致的焊点开裂，通常也在表面开始并向内传播。因此，即使是焊点表面的小裂纹也可能影响高速电子组件的性能。传统的直流电阻测量不适合检测这样的小故障。需要更准确和灵敏的替代品来监测当前和未来电子产品的可靠性。RF阻抗分析提供了一种改进的检测互连退化的方法。这项研究表明，使用射频阻抗的变化作为焊点的物理退化的早期指标，由于集肤效应，并比较这直流电阻测量。在高温下的机械剪切试验已经进行了与阻抗控制的电路板上的表面贴装元件焊接。同时测量直流电阻和时域反射系数，作为RF阻抗的测量，而焊点的应力。观察到RF阻抗响应于焊点的开裂早于DC电阻而增加。这些结果在多次试验中具有定性重复性。
The trend for many types of electronic products is toward higher operating frequencies or digital bit rates. At high frequencies, signal propagation is concentrated at the surface of interconnects, a phenomenon known as the skin effect. Degradation of interconnects, such as cracking of solder joints due to fatigue or shock loading, also usually initiates at the surface and propagates inward. Therefore, even a small crack at the surface of a solder joint may affect the performance of high speed electronic assemblies. Traditional DC resistance measurements are not appropriate for detecting such a small fault. More accurate and sensitive alternatives are required for monitoring the reliability of current and future electronic products. RF impedance analysis offers an improved means of sensing interconnect degradation. This study demonstrates the use of RF impedance changes as an early indicator of physical degradation of solder joints, due to the skin effect, and compares this to DC resistance measurements. Mechanical shear tests at an elevated temperature have been conducted with an impedance- controlled circuit board on which a surface mount component was soldered. Simultaneous measurements were performed of DC resistance and the time domain reflection coefficient, as a measure of RF impedance, while the solder joints were stressed. The RF impedance was observed to increase in response to cracking of the solder joint earlier than the DC resistance. These results were qualitatively repeatable over multiple trials.