自聚焦共焦式微小内腔体探测技术

Measurement of Miniature Cavities Using a Confocal Microscopy with a Gradient-index Lens

系统用自聚焦透镜代替共焦扫描显微镜中的聚焦透镜 ,将自聚焦透镜体积小的特点与共焦显微技术的轴向高分辨力和绝对位置跟踪特性有机结合 ,具有测头微小型化 ,高的轴向分辨力、较大倾斜表面的瞄准能力、对突跳位置的绝对跟踪能力等特点。选用PZT作为轴向扫描驱动元件 (线性范围± 5 μm ,每个脉冲 2nm进给 ) ,用高精度电容位移传感器作为位置跟踪元件 (线性范围± 5 μm ,分辨力 1nm)。对 2 0°角度块进行测试实验表明 ,在测头直径为 1mm的情况下 ,系统对 2 0°倾斜度以内的斜面轮廓的探测轴向分辨力可达 10nm。

The small confocal inspection technology which is developed by incorporating a gradient-index lens for non-contact high precision measurement of small internal contours is presented. And it combines high axial resolution and absolute position traceability of a confocal microscope with a small gradient-index lens. This technology features a high axial resolution, small in volume, lope surface aiming ability, and absolute step position traceability. The Piezoceramic is used as an axial driving device, with a linear range of ±5 μm and 2 nm displacement per driving step driven by triangular waveform voltage signal. And the displacement sensor with linear range of ± 50 μm and a axial resolution of 1 nm is used as a position tracer. Experimental result shows the non-continuous contours tracking and aiming can be achieved with a resolution of 10 nm and in a range of ± 1 μm for a angle gauge block of less than 20 degree.