Thermal Stress Analysis And Solder Joints Fatigue Life Prediction Of Typical Package

With the rapid development of microelectronics technology,thermal stress analysis of package devices and solder joints reliability study is becoming an important issue.At present thermal stress analysis and solder joints fatigue life prediction of package chip are carried out via three methods such as theoretical calculation, finite element simulation and thermal cycling test.But the theoretical calculation makes the mode so simplified overly as to large error, thermal cycle test is costly and time-consuming,and there is no a dedicated platform for finite element simulation,the large common software has a complicated operation and a big waste of operating functions, Based on the status above,this thesis puts package device as the research object.Based on typical packaged device,this paper studies the thermal stress analysis method systematically,elaborates the basic theory of thermal stress analysis for device-level chip,summarizes the finite element simulation analysis process, overview of commonly used test methods.Making the cartridge DIP devices as specific example,theoretical calculation and simulation were carried out respectively, comparing the result to verify the correctness.According to the basis process of thermal structure calculations under thermal cycling load,choosing support software ANSYS and development software Borland C++Builder6,this paper develop a professional custom software for thermal stress analysis and fatigue life prediction,the platform simplifies the process of operation greatly.Combining the specific examples to verify the feasibility and effectiveness of the software,and using the sub-model advanced analysis techniques to ensure an accurate results while reducing computation time and improving efficiency.For Fujitsu's chip BGA-320P-M06,this chapter studies the thermal reliability factors of typical BGA package,my research conducts the influence of thermal cycling load parameters,the geometry size of device structure and solder joints composition on solder joints fatigue life.The regression equation of solder joints fatigue life and solder joints height,solder joints diameter,substrate height and substrate size by using response surface methodology,and carrying out the verification of the regression model to provide a reference for the design and manufacture of the package device.