Development And Application Of Miniature Fatigue Testing Machine

With the rapid development of microelectronics packaging technology,electronic products continue to be minimized,and the size of its interconnected solder joint is also reduced.As known,solder joint is one of the easiest failure parts in electronic packaging.Therefore,the study on fatigue failure of solder joint is particularly important.Fatigue test is an important way to study the fatigue failure of material.A high-performance fatigue testing machine is the key to carry out such a test.In the practical application,the traditional high-frequency and high-load fatigue testing machines have been well developed and widely applied in all kinds of fields.However,the traditional large-scale fatigue testing machines are unable to meet the fatigue testing requirement of solder joints and the study on small load fatigue testing machine is lacked.In this paper,a miniature fatigue tester with small volume,high precision,strong stability and simple operation is developed,which overcomes the shortcomings of traditional fatigue testing machine and complicated operation.The main work of this paper is summarized as follows:(1)This paper presents a model of micro-fatigue testing machine.The three-dimensional modeling software,Solidworks,was used to design the structure of tester machine,and then the generated model is imported into the finite element software,Workbench,for carrying out the stress analysis to ensure the rationality of the whole structure.(2)According to the actual application requirements,the main parts of the fatigue test machine were selected based on the related calculation.During assembling of test machine,portable coordinate measuring arm is used to ensure the assembly accuracy.As for the control of tester,the fuzzy control module and PID control module in LabVIEW software is utilized and the fuzzy PID controller program is designed.The adopted fuzzy PID control strategy can ensure that the device has the advantages of high output precision,smooth running and fast response.(3)Using LabVIEW virtual instrument software development as the upper machine,the flow chart of the program is illustrated in the present thesis and the design method and function of each module is introduced.The developed software testing system has the advantage of simple operation,powerful function,friend interface.(4)In this paper,the stability and precision of the micro fatigue testing machine under the tensile and fatigue tests were verified by the tensile test of solder wire and the elastic modulus test of copper sheet.Finally,in order to study the fatigue life of solder joint in microelectronic packaging,fatigue failure tests of solder joint were carried out by cooperating with the DIC non-contact optical strain measurement system.The fatigue test based on the developed miniature test machine can provide us the experimental data for further carrying out the theoretical and numerical study on the failure in electronic packaging.