Automatic geometry inspection of silicon ingots

Micro-Epsilon has launched a brand new system for the geometrical inspection of ingots called “dimensionCONTROL 8260 for Ingots”. In just a few minutes, the system can inspect the surface of the ingots using several laser optical sensors (line scanners), which automatically measure the side lengths, phase lengths, angles, diagonal lengths and planarity of the side areas.

The automatic measuring system compares target data with actual measured values and then classifies the ingot accordingly. The system calibrates itself automatically to the common ingot sizes of 125mm x 125mm, 156mm x 156mm and 210mm x 210mm. Ingot lengths of up to 2,500mm can be measured.

Calibration of each respective ingot is carried out by using integrated master parts or components. The identification of any ingot defects is performed either automatically with a marking unit or manually. The weight of the ingot also plays a key role in determining the production yield. Therefore, the system can also be supplied with an integrated load cell. The sensor system and base plate traverse along the test item during the measurement process. In doing so, measurements can be performed at specified distances, depending on customer requirements. Typically, geometrical measurements of the ingot are carried out at every millimetre of the traversing process.