Process And Its Optimization Of High Speed LED Die Sorting For Alignment Accuracy

In the 21 st century, the LED lighting industry is developing rapidly. Die sorting is a very important part of the LED industry chain, and the downstream enterprises have high accuracy requirements for the arrangement of the die. This paper focuses on the analysis of the error caused in each link, and the process optimization for improving the sorting precision. The content is as follows:The paper introduces the design of the die sort process and implementation, points out the influence on the alignment accuracy of the each error through analyzing the error of each link. In the end, it put forward the necessity of die pick-up and placement process research.The pick-up process of the die is analyzed in details, and the posture model of pre-stripping in two cases is established. The related parameters are obtained by some experiments, and then we get the solution of the posture model by using Matlab. The paper also analyzes the stress state of the die in stripping process, and obtains the critical pressure to prevent the slippage between the die and the sucker.Moreover, this paper introduces the causes of error in the place link, measurements the position of the arm, and eliminates the deviation of the arm by compensation. It also analyzes the possibility of slippage in the process of placing and the cause of “black die”. The paper analyzes the process of die positioning, Points out the influence of the membrane deformation and angle correction function on die positioning. Then it put forward two methods to reduce the error caused by the above two factors. At last, the paper carries out comprehensive experiment to verify the validity of the method and the process parameters.