Abstract:
LED chips locating is a key link in chips detection, dicing, wafer expansion, die bond and in telling whether the electrical characteristics of the chips and the chips pin can meet the requirements and in telling whether it can sort the LED chips quality successfully. To solve this problem, the coarse-to-fine locating method was put forward. Firstly, the low magnification and high coverage were used to conduct the coarse locating of LED chips' template matching. Then, based on the generated coordinates of coarse positioning, the high-precision locating of high magnification and low coverage template matching within the eight fields of the coordinates were conducted. In this way it could solve not only the fastness but also the precision of the positioning. The results of the experiment show that the image locating precision error is less than 1 m; the moving table locating precision error is 4 m; overall locating system locating precision is less than 5 m; locating speed is greater than 5 grains/second, thus providing a new way for chips high-precision locating system of equipment such as detection machines, sorters and die bonders.