Research And Application In The Integrated Circuit Field Of Reconstruction Algorithm Based On X-ray

With the SMT components’ high density, the actual assembly faults are up to85%duringthe LSI manufacturing and assembly process.However, the existing detection methods such asartificial visual inspection, automated optical inspection are only useful for surface defects.These methods are helpless for the situation when the welding spot defects are on the bottomof the device and other invisible situations.Under such background; defect detection based onthree-dimensional reconstruction is applied in the LSI field. But up till now, domestic researchon this area is still a blank stage.In this thesis, the main research content is three-dimensional reconstruction based on theX-ray. We focus on the step of slice image reconstruction, proposed several reconstructionmodels and corresponding numerical algorithms. Finally, we do some research combined thecharacteristics of the LSI field with the proposed algorithms in the thesis, as follows:1) Because of the slowly converges of ART-TV iterative algorithm, we propose a newalgorithm called P-TV based on the concept of polynomial acceleration, and then,we make an analysis about the parameter values. Numerical experiments resultsshow that the new algorithm is efficient and reconstruction speed is about10timeshigher than ART-TV algorithm. In addition, the acquisition and storage of theprojection matrix method is improved during the experiment. Conventional methodis so complex and time consuming. So, a new simple method is proposed in thepaper and it is easy to programming for acquiring the projection matrix, and then,the concept of sparse matrix is applied to storing the projection matrix, whichgreatly improves the efficiency of the experiment.2) There are some ladder phenomena and pseudo-edge phenomena when we appliedfirst-order TV function as the regularization. However, it will lead to blurred edgeswhen we applied higher-order TV function as the egularization. The paper proposestwo mixing optimization objective function based on the advantages of first-orderTV and higher-order TV. That is Multi-TV function and Mix-TV function. Then, wemake discussion about isotropic TV and anisotropic TV definition. Finally, we makeexperiments with P-Multi-TV algorithm and P-Mix-TV algorithm under polynomialacceleration framework for image reconstruction, and we get a good reconstructionquality.3) We make a discussion about advantages and disadvantages of ROF model andhigher totalvariation model based on the definition of the total variation function space. This thesis presents a hybrid model based on total variation which combineshigher totalvariation model and ROF model. Verified by experiments, this newmodel and solution strategies have great contribution for reconstruction quality. Weapplied Split Bregman algorithm for solving the new model and show a detailedderivation about algorithm, and then, make a point of convergence of the algorithm.Finally, new algorithm shows great adaptability and robustness according tonumerical experiments compared to other algorithms.4) For the characteristics of the image in the field of integrated circuits, we prompt animplified reconstruction model and give the corresponding solution algorithm.Algorithm greatly improves the speed of reconstruction whileguarantees the qualityof the reconstruction image.So, the algorithm is verified more suitable for real-timedetection needs according to experiment analysis.