Design And Simulation Analysis Of Automatic Hot-Pressing Indium Sealing Equipment

As a kind of soft metal sealing technology, indium sealing can realize the unmatched packing of materials with different coefficient of thermal expansion, which is widely used in the vacuum sealing process of glass-parts and metal-parts. As it is more and more widely applied in the fields of aerospace and aviation, the requirements of automation level, production efficiency and sealing accuracy of the sealing equipment are more and more strict. However, most of the high-performance sealing equipments are usually complex and expensive, so many medium and small-sized enterprises and scientific research institutions cannot afford them. Therefore, this paper develops an automatic hot-pressing indium sealing equipment, which has advantages of simple structure, low cost, high precision and high automation level.The equipment is mainly composed of a hot-pressing device, a3-DOF manipulator and a2-DOF cavity adjusting-platform. The hot-pressing device including a pressure-displacement control system and a heating device adopts a three-column frame, which has enough deformation stiffness and operating space. In the pressure-displacement control system, a three-phase stepping motor and a screw jack are used to form the pressure actuator. A force sensor and a granting ruler are used to measure the sealing pressure and the heating device’s position to realize the pressure closed-loop control. The heating device composed of heating body and electrode adaptation ring can apply to electrodes in different shapes. A vacuum chuck is used in the3-DOF manipulator to pick the electrode. A compliant mechanism and a visual detection device are also integrated in the manipulator to protect the electrode and detecting the cavity’s position. The2-DOF cavity adjusting-platform is used to adjust position of the cavity to ensure its accurate location.Through researching thermal performance of the heating device and the pressure uniformity by using the finite element analysis software Ansys Workbench, this paper determines influencing factors of pressure uniformity, influences of the pressure uniformity on sealing quality, heat insulation effect of the parts and temperature uniformity of the heating surface. Meanwhile, a method for improving pressure uniformity between the two sealing surfaces is proposed. Besides, temperature of different locations on the heating surface is measured by experiment. It is proved that the equipment can satisfy the use requirements well.The automatic hot-pressing indium sealing equipment developed in this paper has been used in practical production. The application result shows that the equipment has advantages of high sealing precision and production efficiency. Moreover it can realize the mass and automatic production.