Automatic Hot Pressing System for Indium Packaging

Hot pressing is one kind of effective assembly technology to join two parts together. Automatic hot pressing need control both temperature and pressing force precisely and programmable. In this paper, an automatic hot pressing system for indium packaging is presented, the design motivation is to made the system reliable for application in industry and reach the accuracy requirement. A screw jack with servomotor is selected to actuate the hot pressing head to generate the pressing force, a linear encoder is used to detect the displacement of the screw jack to improve its motion accuracy. A force sensor is mounted underneath the 2-D platform to feedback the pressing force in real time. The hot pressing head is made up of four heating rods and a temperature sensor to control the pressing temperature. The exchangeable manipulator is designed to pick up parts with different size and shape. The machine vision is employed to calibrate the first set of parts to make the system flexible to product variety. The experimental results shown that the maximum force error is 9 N at working load of 2000 N and the temperature error is less than ± 0.3°C. The cycle time is 630 s. (paper)