Research On Hot-pressed Indium Packaging Control System For Precision Device

Indium packaging is an important connection and sealing method.It has the advantages of good sealing performance,simple structure and high cost performance.It is often used for the connection and sealing of metal and non-metal such as metal and glass.Indium sealing has the same advantages for precision devices where the outer casing is entirely metallic.Compared with traditional connection methods such as bolts,it is necessary to control process parameters such as temperature,force and time during the indium packaging process to ensure proper indium layer thickness and sufficient joint strength.It is difficult to ensure the quality and consistency of sealing by manual work.The development of automated hot pressing packaging equipment is expected to solve the above problems and realize the application of indium packaging in precision device products.This paper has developed a control system for precision device hot pressed packaging equipment.Different control strategies are used for different process parameters.The combination of application software and hardware enables the control system to automatically control process parameters during the indium packaging process.A good human-computer interaction interface is designed,and the user can conveniently implement the hot-pressed packaging process of the precision device and monitor the process.First of all,the hot-pressed indium packaging process of the precision device and the key technology of the hot-pressed control process are analyzed.According to the main structure of the equipment and the performance index requirements of the equipment,the overall control plan is developed accordingly.The corresponding control unit is designed for the main control parameter including temperature and force of the hot-press sealing process.A combination of a temperature controller and a thyristor phase shifting trigger is used to steplessly adjust the heating power of the temperature control device.Compared with metal and non-metal indium seals,the two components of the shell to be sealed are metal materials.While metals have excellent thermal conductivity,two temperature control devices are designed that operate simultaneously and independently.The position-based impedance control method is used to control the pressure sealing force by using the displacement control device and the load cell.In the hot-press sealing process of the metal shell,it is also required to ensure the alignment of the shell with the upper temperature control device.Positioning stops and positioning cylinders are then used to determine and adjust the position of the metal shell.Secondly,the appropriate interface circuit is designed for each control unit of the control system,and the appropriate hardware is selected.Then,the appropriate hardware is selected.The hardware control method of each module is described in detail.After the hardware design is completed,the control software of the hot-pressed packaging system is developed by using the LABVIEW development environment,and a good human-computer interaction interface is designed.Based on the idea of modularization,the program control strategy of the "producerconsumer" mode is determined.The event detection is used to trigger the operation of each control unit,and the interaction of each control unit program is realized.The control flow is written into the queue of the program in order to realize the automatic operation of the indium sealing process.The software also saves process data such as temperature,seal force and time during the hot-pressed packaging process.Then,the performance of the developed equipment are tested,including temperature performance and force performance.The experiments show that the performance indexes of the equipment can meet the requirements of the hot-pressed indium packaging operation.The actual hot-pressed indium packaging test was carried out with the developed equipment,and the reliability and sealing performance of the joint were tested.The results show that the sealing performance and reliability of the precision device can meet the product requirements.