用高速摄像系统记录不同打火参数下打火杆放电、尾丝熔化成球的序列图像。通过MATLAB对图像进行图像处理，得到最终成球直径及其球心与尾丝的偏距。实验发现，在较大的打火电流(I=60mA)或较小的预设球直径(D=40. 64μm) 等条件下，球心与尾丝中心线的偏距不稳定且相差较大，易出现高尔夫球现象，严重影响引线键合的质量。

使用红外测温仪对加热台及微型叠层芯片表面进行测试，对所获得的温度数据进行分析建模。发现叠层芯片结构表面悬臂区域和非悬臂区域的温度存在差异，并讨论其原因。进一步对不同区域的温度曲线进行拟合，发现Logistic模型可用于叠层芯片结构测温数据的建模和阐释其温升机制缘由。实验结果有助于叠层芯片悬臂键合动力学机理的研究。

Microelectronics packaging has been developing rapidly due to the demands for faster, lighter and smaller products. Printed circuit boards (PCBs) provide mechanical support and electrical interconnection for electronic devices. Many types of composite PCBs have been developed to meet various needs. Recent trends in reliability analysis of PCBs have involved development of the structural integrity models for predicting lifetime under thermal environmental exposure; however the theoretical models need verification by the experiment. The objective of the current work is the development of an optical system and testing procedure for evaluation of the thermal deformation of PCBs in the wide temperature range. Due to the special requirements of the specimen and test condition, the existing technologies and setups were updated and modified. The discussions on optical methods, thermal loading chambers, and image data processing are presented. The proposed technique and specially designed test bench were employed successfully to measure the thermal deformations of PCB in the 40 C to +160 C temperature range. The video-based moir!e interferometry was used for generating, capturing and analysis of the fringe patterns. The obtained information yields the needed coefficients of thermal expansion (CTE) for tested PCBs.

The effect of the temperature on bondability and bonding process for wire bonding are investigated. Bondability is characterized by shear bonding strength and bonding process is represented by input and output power of ultrasonic transducer. A laser Doppler vibrometer and Labview software were used to record the velocity, voltage and current of transducer at different temperature settings. A K-type thermocouple sensor was used to measure the bonding temperature. Experimental results show that unsuccessful bonding happens at low temperature, and over bonding appears if the temperature is too high. Only when the temperature is at appropriate settings, can a stable and satisfied bondability be attained. The reason for this experimental observation is analyzed. By using a high resolution transmission electron microscope, the atom diffusion depth of Au-Ag bonding interface was measured and the result is about 200 nm. By using joint time-frequency analysis, the instantaneous characteristics of bonding process were observed completely and clearly. It is found that input and output ultrasonic power vs. time-frequency in a bonding process, including resonance frequency, harmonic components and amplitude of ultrasonic energy, vary along with the change of temperature settings.

The goal of this research is to develop a systematic, accurate and robust method for printed circuit board (PCB) positioning evaluation in the testing fixture. Theoretical analysis and experimental observation of tolerance distribution in bed-of-nails fixture were involved. Actual deformation of PCB (translation, rotation and deflection) could be obtained based upon a proposed model. The combined accuracy of the test lands positioning (false failure rate) were estimated by the Weibull distribution. All data processing was finished by MATLAB. Results will be helpful for evaluation of the minimal size of the PCB test lands and modification of the testing fixtures.