In-situ SEM/TEM Tensile Testing Of Microsoldered Joint And Ceystal Orientation Of Sn-Cu Imcs

To high density microelectronic packaging, high integration development, the size of micro-interconnect was more and more tiny. With regard to lead-free solder, when its size decreased to micrometer, the interfacial IMCs increased proportion of solder joints, there will bring significant negative effects to mechanical properties of solder joints. So there are great theoretical and practical significance to study the effect of intermetallic compounds on the mechanical properties of micro lead-free solder joints and micro-fracture behavior.In this passage, the Sn3.0Ag0.5Cu/Cu micro joint was researched. First of all investigated the thickness and shape of interface IMC (Intermetallic Compound), measured mechanical properties of IMCs by nanoindentation; and then the regulation of interface IMCs'orientation in the solder was investigated with the technology of electron backscattered diffraction; finally observe the micro-fracture behavior of micro lead-free joint with different aging time by SEM and TEM in-situ tensile test, analysis the effect of IMCs on the deformation of solder joint. In addition, observe and analysis the real physical process of crack tip, discuss the impact of IMC on the crack propagation.The results showed that on the top or sides of long time aged Cu6Sn5 have small plane with one or two corner, the angle is about 120°. And discoid shape of circular defect exist on Cu6Sn5 layer was observed. The thickness of IMCs layer is greater of small volume solder joints with higher growth rate of Cu6Sn5 than large volume solder joints. The rule about nanoindentation hardness is: Sn-rich phase