复制高精度大光栅盘时支撑板的力学分析

Mechanics analysis of bearing board when reproducing supreme diameter and high precision grating

为了复制高精度、大直径薄光栅盘,对曝光装置中影响感光条件的支撑板进行了受力分析。将支撑板的力学分析归结为边界简支的圆形薄板的小挠度问题,通过理论计算得到了支撑板的挠度和厚度的计算关系式,为设计支撑板提供了理论依据。根据理论推导,选择旋转式曝光装置,采用直径为1000 mm、厚度为40 mm的支撑板,研制出了较高精度的大直径薄光栅盘,其最大直径误差为0.47″,均匀性误差为8%,满足了使用要求。

To reproduce the supreme diameter and high precision grating, the mechanical properties of bearing board in exposure equipment for reproducing grating was analyzed. By summing up the mechanical analysis on bearing board into a flexibility problem, the formula of the relationship between flexibility and thickness was deduced by theoretical calculation. On the basis of the formula, an exposure equipment with bearing board in thickness of 40 mm and diameter of 1 000 mm was used to reproduce a high precision and large diameter thin grating successfully, experimental results show that the biggest diameter error and uniformity error of the grating is 0. 47＂ and 8%, respectively, which can meet the requirement for angle measurement system.