Study on nano-inprocess measurement for flexible micromachinig

已开发出尺寸小于几毫米的微型机械，如微电机、微型直线驱动器、微型泵等。近年来，利用硅表面微机械加工技术和另一种新兴的微机械加工技术制造了各种微机械。微机械部件的精度要求达到亚微米量级。为了高效地制造更细尺度的形状，有必要开发熔融微加工的在线测量和评估技术。测量原理是基于光学傅里叶变换和相位恢复方法。为了提取测量技术中的位相信息，基于对数希尔伯特变换和傅里叶级数展开的位相恢复算法由两个夫琅和费衍射强度得到，这两个衍射强度与有或没有…的物场的傅里叶变换模平方有关此外，还应用了对象平面上的指数密度过滤器。我们的测量技术可以从两个夫琅和费衍射光强分布的激光照射下重建出工件整个区域的三维形状。为了验证该方法的有效性，我们进行了细槽模型重建的计算机模拟。明确了槽型尺寸参数与指数密度滤型之间的关系。此外，还研制了由傅里叶变换光学系统和指数密度滤波光学系统组成的逆散射测量系统。利用该测量系统对超精密金刚石车削加工的节距为9.1 mm、深度为0.4 mm的微小三角槽进行了测量。重建的轮廓与使用传统触笔方法测量的轮廓基本相同。结果表明，该测量方法在不需要扫描探头和测针的情况下，能有效地重建出微米级零件的轮廓。较少

The micromechanism of which size is smaller than a few millimeters for examples micro-motor micro-liner drives, micro-pumps, etc has been developed. In recent years a variety of micromachines have been fabricated by silicon surface micromachining techniques and another new developed micromachining techniques. Accuracy of components of the micromechanism is required to be of submicrometer order. It is necessary to develop in-process measurement and evaluation techniques for the fusion micromachining in order that the efficient fabrication of finer scale form is performed.The principle of measurement is based on the optical Fourier transform and phase-retrieval method. In order to retrieve the phase information for our measurement technique, the phase-retrieval algorithm based on the logarithmic Hilbert transform and the Fourier series expansion from two Fraunhofer diffraction intensities which are related to the square of the modulus of Fourier transform of object field with and without … More an exponential density filter at the object plane is applied. Our measurement technique makes it possible to reconstruct three-dimensional form of the whole area of a workpiece which is illuminated by the laser beam from two Fraunhofer diffraction intensity distributions.In order to verify the validity of the proposed method, computer simulations of reconstruction of the fine groove model is performed. The relation between the size parameters of groove profile and the exponential density filter type is made clear. Moreover, the inverse scattering measuring system which is composed of the Fourier transform optical system and the exponential density filter optical system is developed. By using the measuring system, the measurements of the fine triangular groove with the pitch of 9.1mm and the depth of 0.4mm which is fabricated by ultra precision diamond turning is carried out. The reconstructed profile is much the same as the profile which is measured by using the conventional stylus method. It is shown that the proposed measurement method is effective for reconstructing the profile of a micrometer size workpiece without scanning probe and stylus. Less