Micro-mechanical evaluation of electronic packaging and a MEMS material

SIEM (Speckle Interferometry with Electron Microscopy) is a micro/nano experimental mechanics technique. It is able to perform full field displacement mapping over a region of only several microns in diameter. With the especially designed micro-loading device, SIEM can perform testing on specimens with dimensions from microns to millimeters and from room temperature to elevated temperatures.; In this dissertation, SIEM is applied to the study of the thermal deformation in solder joints and interconnect layers. With spatial and displacement resolution in the nanoscale, SIEM is an ideal technique for testing solder joints and on-chip interconnect structures. From the obtained deformation of solder bump, underfill material, silicon die, and interconnects, both Cu-Si₃N ₄ and Cu-SiCOH interconnects show good reliability.; SIEM is also used to micro-evaluate the mechanical properties of EPON SU-8, which is a MEMS material that is often used to produce high aspect ratio structures in MEMS devices because of its low cost. It is found that the mechanical properties of EPON SU-8 are indeed dependent on the size of the specimen. Furthermore, the mechanical properties of EPON SU-8 are compared at different temperatures. When the temperature is 105°C, no major differences in mechanical properties are found compared to those at room temperature. However, when the temperature reaches 347°C, the Young's modulus of EPON SU-8 decreases 83% from that at room temperature. In the cyclic loading process, Young's modulus increases with each cycle during loading processes and decreases with each cycle during unloading processes. Additionally, Young's modulus is larger during unloading. Finally, the strain concentration in micro/nano scale is investigated in a cross-shaped specimen and a specimen with a hole.