Research On Feature Recognition Method Of Typical Defects In TSV Three-Dimensional Packaging

With the rapid development of microelectronics technology,microelectronics devices have to meet the packaging requirements of high integration,miniaturization and high reliability,TSV three-dimensional packaging technology has attracted wide attention due to its high integration,low latency and low power consumption.At the same time,small aperture,high density and high aspect ratio are gradually becoming the mainstream development trend of TSV three-dimensional packaging.It is easy to cause the frequent occurrence of defects,which will lead to a series of reliability problems.Most of these defects are concentrated in wafers and chips,and it is difficult to detect them directly by conventional methods.Therefore,the internal defect detection of TSV three-dimensional packaging is facing new problems and challenges.This paper was based on the study of internal defect response mechanism of TSV,the distribution of temperature and stress under defects were obtained by combining theoretical analysis,finite element simulation and experimental verification,and the corresponding defects were identified and located.By mastering the external manifestation of internal defects in TSV,the problem of difficult detection of internal defects in three-dimensional packaging could be solved.The specific work was as follows:Firstly,the common methods of TSV defect detection were comprehensively expounded.Combining with the basic structure and working mode of TSV three-dimensional packaging,the heat conduction process in TSV three-dimensional packaging was analyzed emphatically.The differential equation of heat conduction and thermal resistance network model in TSV three-dimensional packaging were established.On this basis,the stress-strain analysis was made to provide theoretical support for subsequent simulation and test.Then,the three common internal defects of TSV: the filling missing,cracks and bottom voids.The finite element models were established respectively,and the finite element analysis was carried out under the coupled thermal-electrical and thermal-structural conditions.Finally,the required TSV test samples were designed and prepared,and the measurement and test system were built.The test results showed that:(1)The biggest difference in temperature was filling the missing TSV,followed by the bottom void TSV,and the smallest difference was the TSV with cracks.(2)For the two defects of filling missing and bottom void,the temperature at the center of the copper column decreased with the increase of the diameter of the TSV copper column.It could be seen that the experimental and simulation results are consistent.Therefore,the characteristics of the external temperature and stress difference caused by the internal defects of TSV could identify and detect the internal defects of TSV,and provided guidance for the subsequent theoretical research on internal defects of three-dimensional packaging of TSV.