Research On High-precision Solder Testing System Based On Line Laser Scanning

The chip packaging and testing process is an important link in the integrated circuit and microelectronics industry,and its quality control is one of the very important steps for power device products,especially automotive products.With the development of computer technology,communication technology and other disciplines,automatic thickness detection technology based on machine vision has been greatly developed.It extracts useful information from the collected images and performs a series of processing on the information to obtain a three-dimensional image Z The value in the direction.This technology will become the key research direction of dimension measurement in the microelectronics industry,and will be of great significance for improving production efficiency and improving product quality.Compared with the traditional method,this method has the advantages of high test accuracy,fast efficiency,high degree of automation,and non-contact measurement.The paper first introduces the development history of thickness measurement and the research on the methods and methods of thickness measurement at home and abroad.The first part of the paper mainly investigates several main methods of current three-dimensional measurement.After comparison,it is found that the laser triangulation method has better performance.Then the specific principle of the laser triangulation method is explained,and the method is introduced for high-precision measurement of the thickness of the film mount.Applied research.By comparing the two laser triangulation methods,the direct-fire laser triangulation method is selected to be applied to the thickness measurement of the film mount.In terms of detection accuracy,if only marking by laser triangulation can not achieve ?m level calibration,this is caused by the gap between the CCD imaging units,so when the measurement calibration is performed,the relevant depth recognition algorithm is also used.As a supplement,to make image recognition more accurate.The paper mainly introduces the hardware structure of the measurement system and the movement process of the measurement.Among them,the linear motor and the encoder are used as the direct structure of the motion control,and the PLC control encoder is used to drive the linear motor for motion control.The imaging system is the core component of the entire measurement system.In this paper,the mathematical model of the measurement system is researched and designed and the appropriate imaging structure is selected — an image receiving system that combines a bi-telecentric imaging lens and a CCD imaging device.This system can obtain more The clear original image,together with the establishment of an image measurement system that can be used for experimentation,can receive the image data in real time.To this end,a set of real-time image receiving and processing system has been researched and developed,and the lower computer system is designed and built using the DSP software development platform.Its main functions include the selection of the measurement object mode and scanning mode.Combining image feature algorithm,image filtering algorithm and gray centroid algorithm to filter,extract and calculate the acquired image.A detailed comparison of algorithms of the same type is made.The currently available scanning methods are mainly single-point scanning,continuous scanning and cyclic scanning.Finally,the measured data was verified by MSA,and the accuracy of the measurement results and measurement speed of different measurement methods were analyzed.The final result indicated that the measurement accuracy of the system was above the measuring microscope,and continuous scanning tests could be performed,which greatly reduced In order to realize the BLT automatic detection,it provides a complete set of methods.Reduced production costs,reduced investment in human resources,has a broad market prospects.