Research On The Measurement Technique Of The 3D Of Soldering Paster's Printing Quality

As the important link of electonics manufacturing industry,the autonomous testing technique of the soldering paster's printing quality is always one of the research highlights of the engineering field.Mechanical vision inspection technology has the advantages of high efficiency,precision and convenience,which has been widely used in the detection link of the electronics manufacturing industry.Grating projection method is one of the common research methods of the 3D outline reconstruction technology.Besides,it has the advantages of high precision,fast speed and low requirement on environment.Aiming at the research background of the 3D measurement of rectangle's solder joints,the article provides two detecting methods that integrates the plane measurement of machine vision's with grating projection height measurement to systematically research the three-dimensional information detection technology on soldering paster's spot mass.The work of the essay mainly includes the following aspects:Firstly,use the Halcon software of machine vision and connect image threshold segmentation,image characteristics extraction,algebraic calculation images and other image theories to analyze the solder joint image of the tested rectangle and obtain the two-dimensional information of the rectangles' solder joint.Through the mean values,relative error values and the standard deviation,conduct the analysis on measurement results,which shows that the method can realize the two-dimensional high-precision measurement of the rectangle's solder joint.Meanwhile it could identify if the solder joints were printed legally.Secondly,As for the soldering paster's height measurement,it uses the methods that combine the Halcon software of macine vision with laser triangulation principle to analyze and measure the migrated image of solder joint strips.The results show that because of the errors of angle control of experimental facilities and the strip deviation produced by slight measuring height are not clear,it leads to the larger positioning errors.It has been introduced that the method of grating projection in order to improve the measurement accuracy of solder joint's height and then use four-step phase-measuring method and phase-unwrapping algorithm to demodulate the actual phase information of the deviation from the distorted grating fringe images.According to the mapping relation of height and phase,the height information of welding spot can be obtained.Simulation experiments show that the way can achieve more precise result of height measurement,so that it can achieve the online automatic identification of soldering paster's printing quality.Then,Aiming at the low precision problems during the process of ordinary cameras adopting the large-size PCB image,it has researched image mosaic technique based on corner characters.Based on the platform of Halcon's software,it has designed three different kinds of stitching methods and has researched the objective appraisal methods of mosaic quality.Through three kinds of mosaic results-time,the number of interesting points and the value of DoEM,it has achieved the image mosaicing method with better splicing effect.In the end,it realizes the human-computer interface through setting up the software platform of soldering paster's printing quality's 3-dimention test including three models of the above soldering paster's 2-dimension information,height information as well as PCB image stitching and mixing various modules together to compile by utilizing the three software platform-Visual Studio,matlab and Halcon.