Microstructure and bonding mechanism of anodic bonded interface between pyrex glass and kovar alloy

Under the condition of technological parameters of anodic bonding, the temperature in range of 300-500℃, the voltage in range of 400-650 V, and time being 10-20 min, Pyrex glass and Kovar alloy can be quickly joined.By means of the high resolution scanning electron microscope, super-light element spectrometer, transmission electron microscope and X-ray diffraction instrument, the microstructure of joined interface, tiny area chemical composition, phase structure of tiny area of interface were analyzed.The results indicated that the joining process of Pyrex glass and Kovar alloy can be divided three stages:interface polarization and electrostatic adsorption stage, the ion transferring and anodic oxidation stage, oxide solid phase diffusing or union and transition region formed stage. Interface electrostatic force and ion diffusing or motion provide requirement for the physical chemistry reaction of the interface combining.The joint of Pyrex glass and Kovar alloy is composed of glasstransition region-metal, and the main structure of transition region is spinel oxide, and chemical composition and its compactible degree has quite great effect on joint strength.