Precitec Optronik GmbH

Thickness measurement of an opaque object

If the thickness of e.g an opaque object is to be determined, two measuring heads are required, one from each side. By referencing with a test standard of known thickness, the thickness of the object can be obtained from the data on the distances to the two surfaces. This principle is not affected by displacements or vibrations of the object. If it comes closer to one measuring head, it moves away from the other; the calculation of the thickness is not affected. This makes the system highly suitable for inline applications where, for example, a passing strip (as an object) cannot be guided or only guided to a limited extent, or for roll-to-roll applications with high web speeds. The CHRocodile 2 DPS sensor can measure at up to 10 kHz, which means that even large or fast-moving objects can be closely scanned.

Step height measurement

Another possible application is the instantaneous determination of a step height without the time-consuming acquisition of a complete profile of the step. If both measuring heads are oriented in the same direction, the height difference between two locations on a surface can be determined. This is interesting, for example, for continuous inline control of the thickness of a coating or to determine the thickness of an object that cannot be reached from the bottom for geometrical reasons. For example, the thickness of a wafer on a chuck table can be determined by measuring the step height between the wafer surface and the chuck table. The internal calculation and referencing can be easily adjusted to this situation so that the CHRocodile 2 DPS directly outputs the calculated step height without further post-processing.

Thickness information can also be included in this application so that composite objects with transparent layers can also be measured here.

When it comes to integrating inline inspection systems into a production environment to enable thickness and distance measurements, space can be an issue. If the inspection device is too large, integration will be a problem. With the new CHRocodile Mini space is never an issue. This low-price, ultra-compact 3D confocal sensor usefully combines maximum performance with minimal size.

Useful application flexibility

The CHRocodile Mini is a confocal sensor that enables precise and stable non-contact thickness and distance measurements on any kind of material from the kind of small footprint that is invaluable in confined production conditions. This compact device is ideally suited to applications such as determination of positions and dimensions (e.g. for electronic components), topography, profile and roughness measurements (e.g. for tool surfaces) and thickness measurements of glass or plastic coatings.

Attractive alternative to laser triangulation

Weighing just 500-550 g and a mere 95 x 106 x 95 mm in size, the CHRocodile Mini is the ideal ultra-compact confocal 3D sensor for inline inspection applications. The separate optical probe and controller can be integrated into almost any small space for inspection purposes. As a powerful favorable alternative to laser triangulation sensors, this state-of-the-art chromatic confocal sensor uses high-performance optical lenses to focus white light at different distances along the optical axis. Moreover, coaxial measurement technology offers the added advantage of avoiding shadowing effects, which alternative measuring technologies cannot.

The chromatic confocal line sensor CHRocodile CLS 2Pro offers the best combination between line length, angle acceptance and speed. It is highly suitable for applications in semiconductor industries.

The 3D structure of your sample is determined in a very short time through fast line scanning at up to 36000 lines per second – ideal for inline applications where cycle time is critical.

The chromatic confocal measurement technology provides data with an extremely high lateral and axial resolution, enables measurement of any kind of material, and functions without shadowing effects – even for complex geometries.