Development of a Mechanical Test Machine to Simulate the Thermal Cycling Reliability Test for Electronic Components

• Main Authors: Chien-Lin Hung, 洪建霖
• Other Authors: 陳永樹
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/95132150976976428627

碩士 === 元智大學 === 機械工程學系 === 98 === The accelerated thermal cycle(ATC) test was probably one of the most important tests among the electronic reliability tests. It is time consuming and always causes a bottleneck in the lab loadings. Therefore, the mechanical bend and shear tests were often used as alternatives for the ATC test. But it is a general guideline that the reliability test results are meaningful only if the mechanical stresses applied on the test components are the same or similar to those stresses found in the ATC test. However, those mechanical stress test machines currently used were just those general purposes material properties test machines. Normally, it can apply only half of the stress cycles, not even the dwell time in ATC tests can be simulated. Besides, it appears to be bulky and over specifications for its loading capacities for today’s miniaturized electronic components. Based on improving these drawbacks, the study developed a miniaturized electronic components testing machine with the features of mimicking stress states in the ATC tests. The developed machine was verified with a series of cyclic bend tests on flip chip components that either with leaded or lead free solder balls. In the initial of design processes, the design specifications of the machine were established then the structure analysis was also conducted with finite element analysis. The final check-ups of the machine precision such as the desired displacement and parallelism of the two main structure columns were also performed. Finally, cyclic bend tests were performed on the machine with the several electronic components of different types. The corresponding results were compared with those tested on the bigger general purpose test machine originally used. The designed machine was capable of applying both positive and negative stresses that resemble the stress states on the ATC test. Moreover, it could also set the dwell time in the peak displacements of each cycle that corresponds to the constant temperature section on the temperature profile of the ATC test. This probably was the unique feature comparing with the universal test machines. The resulting test cycles before failure when tested with this kind of positive and negative mechanical stresses were found to be only quarter of those test cycles on the original test machine which can apply only either positive or negative cycles only. The test results are quite consistent with limited test samples. However, it is believed that if more test samples are available, the same consistency of the test results still exists that will make the outcomes more convincible. It has shown that this kind of miniaturized test machine can save cost and space and the applied stresses are also closer to those in the ATC tests.