Reseach On The Correlation Of Wire Bonding And Intermetallic Compound

With the development of high density and small scale in integrated circuit(IC), the research on electronic packaging especially on the wire bonding techniques on the IC and frames bonding joint has been the main concern. Since the 21 st century, wire bonding technique is the main electronic packaging technique for its low cost and high quality in contrast with other packaging techniques. In order to increase the reliability and reduce the cost of microelectronic components, Cu has been the optimum material of wire bonding for its significant features. In contrast with silver and golden ball wire bonding techniques, the reliability and intermetallic compounds(IMC) formation on Cu balls and Al alloy pads in the thermal aging process was analyzed based on Cu ball wire bonding technique in this paper.In order to study the reliability and intermetallic compounds formation of the bonding joint in the thermal aging process, a central composite design of experiment approach was applied to optimize the parameters of bonding process and the bonding strain of the joint on the chips with the most stable performance in test.In contrast with reliability and IMC formation on Au-Al bonding joint, the Cu-Al and Ag-Al bonding joints were researched, separately. The whole process of IMC formation and interfacial evolution and fission behavior of joints was investigated in the thermal aging experiments at 150 ℃ and 250 ℃, separately. Scanning Electron Microscope(SEM) and Energy Dispersive X-ray Spectrometer(EDX) were adopted to establish a kinetics model of IMC formation and analyze of IMC formation rates. With the help of a device model established by ANSYS, we could improve the reliability and optimize the structures of devices by modelling IMC formation under the thermal and stress status.