Analysis On The Interface Structure And Finite Element Simulation Of The Anodic Bonding For The Pyrex Glass To Aluminum

Anodic bonding is an advanced technique for the bonding of metal, semiconductor and ceramics, which is applied to seal and fabricate the micro-electro instruments. It will become more and more important in the field of micro-electro instruments.In this dissertation, the bonding technique for glass to aluminum and multiple layers of wafers are investigated. The bonding mechanism and bonding parameters are discussed. The SEM, EDS and Instron 5544 machine are applied to observe the interface microstructure, to evaluate the bonding strength of the bonded samples and then discuss the bonding mechanism based on them. The ANSYS software is applied to calculate the residual stress and deformation of glass-Al and glass-Al-glass due to mismatch of dissimilar materials.It is shown that the ions diffusion and the anode oxidization are necessary in order to get anodic bonding accomplished and voltage and temperature are key parameters that influence the quality of anodic bonding. The higher the voltage and the temperature, the denser the chemical bond in the interface will be and then the better quality the bonded joint will have. An obvious transitional layer is found in the bonding interface and the EDS results indicate that ions have mutual diffusion across the interface and the elements distribute in the pattern of gradient. Based on the experiment of glass-Al, the common anodic bonding is tried to get multiple layers bonded together. In this process, three layers are bonded by interfaces reaction at both sides, which owns to the static electric field and depletion layer produced by ions diffusion. It is indicates that the common anodic bonding is reliable for bonding of multilayer wafers.The results of finite element analysis (FEM) of the bonding structure of glass-Al and glass-Al-glass show that the three-layer sample has less deformation and residual stress because of its symmetric structure than the two-layer sample obviously. The residual stress increases with the increase of temperature almost in line. Both the three-layer and the two-layer samples have a bigger shrinkage in the interface of glass and Al.