Research&Development Of Automatic Sol-dering Machine Of Chip Package

At present, the front part of chip package such as SMA (DO-214AC) is done almost byhand in Chinese small and medium enterprises. In order to deal with the problem of low efficien-cy, not high quality, high labor intensity and so on, automatic soldering machine using for chippackage is developed, which make up these deficiencies. On the other hand, using of machinevision makes the device can identify positive and negative of the smaller chip, so that enterprisescan expand the family of packaged products. The main contents of this paper are related to thestructure design of automatic soldering machine, finite element analysis, image processing andexperiment.First, through the analysis of current processes, we propose three schemes. There are auto-matic soldering machine with rotary table scheme, automatic soldering machine with belt drivesscheme and automatic soldering machine with machine vision scheme. Considering the long-term strategic planning of the enterprise, we decide to develop vision-based automatic solderingmachines. In the overall structural design of brazing machine using for chip package, dependingon the different function the brazing machine can be divided into five modules based on modulardesign.There are Shake plate supply and recovery module, two-dimensional table module, chippick module, machine vision module, mobile welding fixture module and soldering module.Second, it is adopted a modal analysis for the rack of brazing machine using the finite ele-ment software Ansys Workbench, found the weak link in the rack. After strengthening the weaklinks of the rack, it is adopted a modal analysis for the rack again. Comparing the results of twoanalyses, we can find rigidity of rack improved significantly.Using the image processing software HALCON, we wrote software to extract the chip edgebased on sub-pixel accuracy, and calculated angle of rotation deviation, position deviation andidentified positive and negative of chips in the holes of shake plate. Through experiment, it took60photos of chip, calculated the distribution of positive area and negative area of chip, in orderto provide a scientific basis for distinguishing between positive and negative chips.