Method for the deviation inspection of integrated circuit chip pin based on Harr wavelet transform
Gang Luo · Optical Engineering · 2000
Nankai UniversityInstitute of Modern OpticsOpto-electronic Information Science andTechnology Laboratory, MOETianjin, 300071, ChinaE-mail: [email protected]. A fast method for chip pin location inspection based on theHarr wavelet transform is presented. A cross line at the pin tip is ana-lyzed, and the method locates the central line of a pin according to thezero crossing position of the transform of the 1-D cross line without the-oretical error. The requirement of being theoretically error free is that theconstant segment of the pin image is wider than 2 pixels. The experimentshows a measurement precision of 1/40 pixel.