Experimental study of component placement in solder paste

摘要

The pick-and-place machine from Mydata automation AB, MY9, has two different mounting devices, one for single and one for multiple pick-and-place assembly. The object of this project is to examine whether or not a higher mounting speed in solder paste is possible and what the limitations are. However, not only can the results of this report be applied to present machines, but they could also provide an input for the next generation of pick-and-place machines. To examine the increased speed of component placement at the moment of impact between the component and the solder paste a series of experiments were carried out. The speeds of impact were increased from 100 mm/s in a pick-and-place machine up to 2000 mm/s in a special mounting arrangement. Various components ranging from size 0605 to size 1206, SO 14 and SO 16 were assembled on a PCB with good result. In the series of experiments, some predefined parameters of varying size were used. More parameters could have been used but in accordance with the motivation in this report they were limited to mounting force, mounting speed, various theological properties of the solder paste and different component sizes. Furthermore, in the series of experiments, 0201 components were also tested in the pick-and-place machine with a speed of impact up to 600 mm/s and the mounting accuracy was measured with the Mydata Accur measurement programme. A whole production line for PCB assembly was used at Chalmers-IVF in Molndal and the results of the experiments were carefully documented and archived in the form of data samples and close-up photographs. A number of high-speed films of component placement in the solder paste were taken and tackiness tests were also carried out at the Mydata lab in Goteborg. So far, the processed data and photographs from the experimental samples show that an impact speed of up to at least 2000 mm/s is possible between component and solder paste.