Parameter Measurement Of Bonding Wire Based On Zoom Microscopic Measurement Technology

The parameters such as the arch height and span of gold bonding wires can affect microwave transmission characteristics,especially in radio frequency and microwave chip package.However,the automatic detection equipment for these parameters are mostly imported.Because integrated circuit industry has become the national strategy of world powers and the key technologies and equipment for chip manufacturing are monopolized by a few European and American developed countries.In order to break the blockade on technologies and make up for the vacancy of related research,this study explored the micron-level measurement technology for the arch height and span of gold bonding wires.The details are as follows:First,this study designed and established an image acquisition,processing and experimental platform for the arch height and span of gold bonding wires.Through the embedded scheme,an improved Open CV video acquisition function and a self-designed control software,this study established a real-time image acquisition system with a 270-times magnification and manual and automatic measurement modes.At the same time,based on the Tkinter graphics library,an image acquisition and parameter measurement system was designed to acquire,process and experiment on gold bonding wire multi-focus images.Secondly,this study applied fusion arithmetic and realized the micron-level measurement function of arch height and span of gold bonding wires.This study used FAs T-Match template matching algorithm to locate the vertex position,and used the OSTU method and the global variance to extract the edge area.Then it added the oblique operator to the Tenengrad operator,so as to enhance the sensitivity of the oblique gradient.By performing evaluation operations and locating the lowest point position,this study measured the height of the vault.Then for measuring the span,this study used the multi-directional dual-tree complex wavelet transform(M-DTCWT)to fuse the solder joints at both ends in different images into one image,and used template matching to locate the position of the solder joints.Thirdly,this study explored image processing technologies such as multi-focus image fusion and focus evaluation,and built a three-dimensional model of gold bonding wire.Thus this study realized the micron-level and high-precision measurement for the arch height and span of gold bonding wires.It applied the focal area extraction algorithm to extract the focal area of each image in the multi-focus images,and then mapped the focal area to the three-dimensional coordinates of Matplotlib to obtain a three-dimensional model.By doing so,this study measured the arch height and span with high precision.When extracting the focal area,its color was refined by smooth operation and quantized into 12 color channels.Thus the operation speed was improved.Finally,the measurement method of this study was applied on the gold bonding wire with a diameter of 25 micron.The results were compared with and verified by the manual measurement.It showed that the measurement accuracy of the arch height is less than0.02 mm and the relative error is less than 1.5%;the measurement accuracy of the span is less than 0.01 mm and the relative error is less than 0.7%.This study laid a solid technical foundation for designing automatic detection equipment that help measure the height and span of gold bonding wires in radio frequency and microwave chip package.