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µscan technology
Optical 3D profilometry for large measurement distances
The optical scanning profilometers of the NanoFocus µscan product series are fast and flexible measurement systems for quality assurance and process control. 3D topographies are captured by scanning in a line pattern using a point sensor. This technique allows entire area topographies to be combined from height profiles acquired line by line. Depending on the individual measurement Task, discrete profile lines or 3D measurement data can be represented.
Various µscan sensors are available for the different application areas. The combination of multiple sensors with unique advantages in one system allows the optical profilometer to cover a wide spectrum of measurement tasks in modern production. The sensors offered are based on different functional principles.
Advantages of the optical µscan profilometry
The optical profilometers of the µscan series are suitable for the fast scanning of surface profiles with precision in the low nanometer range. The results show good compatibility with mechanical-tactile reference methods and electron microscopes. The advantage is, however, that the µscan-technology measures 100 times faster than tactile techniques. Additionally, differences in the hardness of the material do not matter because the systems measure without contact and non-destructively.
The profilometers are particularly well suited for long working distances and steep edges. From the data acquired, aspects like geometry (layer height and layer thickness, angles, distances, etc.) warpage, co-planarity, form, waviness and roughness according to ISO standards and many other parameters can be evaluated.
Confocal point sensor – CF
The µscan CF ist based on the most basic confocal method. A light source sheds light on a very small pinhole disc. The sensor detects heightened light intensity when the object is in focus; on the contrary, it detects no light intensity when the object is out of focus.
Chromatic sensor - CLA
The µscan CLA also functions with the confocal principle. An objective lens with high chromatic abberation fulfills the function of the pinhole disc with this type of sensor. A spectrometer measures the heights through color differences. This allows for a surface to be captures in different distances without linear scanning movement along the optical axis.
Holographic sensor - CP
The functional principle of the µscan CP is based on the interference of two light waves. A diffuse point of light is projected on the sample with a laser. The light that is reflected is captured in part in the objective where it meets a crystal. The resulting interference pattern, which contains information about the angles of the incoming light, is recorded by a CCD-sensor and is evaluated electronically. The measurement process is based on determining the distances via the angular sizes. In comparison to classical triangulation, the procedure is more stable because angular errors can be averaged out.
