超薄超短物像距高分辨率检测成像系统设计与试验OACSTPCD

To shorten the axial and radial dimensions of the 12-inch wafer detection imaging system,a solu-tion combining the small angle prism refraction path and the ultra-short object-image distance lens is pro-posed.A small angle prism with shape accuracy better than 1/12λ(λ=632.8 nm)is designed to convert the op-tical path and realize the horizontal arrangement between the lighting system and the imaging lens.The radi-al size is only 80 mm,which greatly reduces the radial size of the whole system without affecting the ima-ging quality.At the same time,a small angle of 12°bright field lighting is realized.A symmetrical hybrid op-tical system with magnification of 0.264 is designed.A pure spherical system is used to obtain a large ima-ging field of view.The image height is 81.92 mm,and the object-image distance is only 392.5 mm,which greatly reduces the axial size of the whole system.The design results show that the average optical transfer function of the whole imaging system is better than 0.4@100 lp/mm,the relative distortion is better than 0.03%,and the uniformity of the image surface illuminance is better than 50%.The actual test results show that the actual imaging resolution is better than 18.88 μm,which reaches the ultimate resolution of the sys-tem.The uniformity of illumination of image surface is 43.3%,which meets the development requirement of uniformity better than 40%.The research results show that the ultra-thin and ultra-short object-image dis-tance imaging system is reasonable and effective,which solves the problem of space size compression of the 12-inch wafer detection imaging system and reduces the development cost.It provides a reference for the de-velopment of the imaging system for detecting large objects in short distance.