Abstract: Based on the assumption of uniformly distributed negative charges in the alkali depletion layer of glass during the electric field assisted anodic bonding process, a theoretical model for the growth of the alkali depletion layer was proposed and the law controlling the growth of the depletion layer was deduced, and the electric field distribution in the depletion layer and electrostatic attraction between surfaces of metal anode and glass were calculated.The results show that the depletion layer grows in the form of hyperbolic tangent function of time, the electric field strength at the interface increases with bonding time to its maximum and the field strength in the bulk glass decreases, and that the fulfillment of the anodic bonding is determined by the completion of intimate contact rather than the charge transfer. Comparison between the results and experimental data indicates that the model is reasonable.
Model for alkali depletion-layer growth during electric field assisted anodic bonding
Abstract:
Based on the assumption of uniformly distributed negative charges in the alkali depletion layer of glass during the electric field assisted anodic bonding process, a theoretical model for the growth of the alkali depletion layer was proposed and the law controlling the growth of the depletion layer was deduced, and the electric field distribution in the depletion layer and electrostatic attraction between surfaces of metal anode and glass were calculated.The results show that the depletion layer grows in the form of hyperbolic tangent function of time, the electric field strength at the interface increases with bonding time to its maximum and the field strength in the bulk glass decreases, and that the fulfillment of the anodic bonding is determined by the completion of intimate contact rather than the charge transfer. Comparison between the results and experimental data indicates that the model is reasonable.