基于多图像融合的MEMS显微三维形貌重构

针对微型机电系统(MEMS)的三维测量,显微镜或光学轮廓干涉仪等传统方法存在显微测量精度低、设备成本高等问题,且当结构含有较多断裂面时,解包裹算法效果欠佳。本文提出一种基于多图像融合的MEMS显微三维测量方法。不同于多角度显微三维测量方法,本研究首先利用单目显微镜,通过单一轴向移动获取一系列测量目标深度信息的单一角度图像,并利用去雾算法对图像进行预处理,实现了去噪和有效信息提取的目的;然后通过聚焦测度算法获取待测对象的深度信息;最后利用数据处理软件进行三维拟合。基于上述原理,本文以焦平面阵列(FPA)作为待测目标进行了测量实验。本文提出的三维测量方法和图像处理算法可获得更准确的FPA形貌,可清晰显示反射面与支腿部分及反射面上的释放孔,测得FPA的支腿长度为110.6μm,每个反射面的像元尺寸为120.8μm×70.8μm,与设计值基本吻合,解决了断裂面难以测量的问题,同时降低了微结构测量的难度和成本。单目显微镜单向移动的多图像融合测量技术对MEMS的三维形貌测量具有重要意义,去雾算法在图像融合与三维测量的图像处理也有很好的应用价值。

Three-dimensional microscopic reconstruction of MEMS based on multi image fusion

In order to realize the three-dimensional measurement of micro electro-mechanical systems (MEMS), it is usually necessary to use a microscope or an optical profilometer. However, the traditional method has problems such as low precision and high cost of detection equipment, and it cannot achieve good results for an MEMS structure with many fracture surfaces. A new method for 3D measurement and image processing was presented in this paper. Unlike the three-dimensional reconstruction measurement method of multi-angle microscopes, this study firstly used a monocular microscope to obtain a series of single point measurements of the target, thus acquiring the depth information through single axial images. Then, a defogging algorithm was adopted for image preprocessing, denoising, and achieving effective information extraction. Subsequently, the depth information of the object to be tested was obtained using a focus measure algorithm. Finally, 3D fitting was performed using the data processing software. Based on the above principle, the focal plane array (FPA) was taken as the target to be measured. The experimental results show that the proposed 3D reconstruction method and image processing algorithm can obtain a more accurate FPA morphology, and can clearly show the release hole reflecting surface and the leg part on the reflector. The leg length of the FPA is measured to be 110.6 μm, and the pixel size of each reflector is about 120.8 μm×70.8 μm, which is consistent with the design value. It solves the problem of measuring the fracture surface, and reduces the difficulty and cost of microstructure measurement. The multi-directional image-fusion measurement technology using a monocular microscope is of great significance for MEMS 3D profile measurement. The defogging algorithm has significant application value in image fusion and 3D measurement image processing.