Kerfloss
The term kerfloss (also kerf-loss from English. Carve (cut in), loss (loss)) comes from materials technology and describes the sawing loss when cutting through materials using thin metal wires.
facts and figures
The aim is to cut through the material with as little kerfloss as possible. The term kerf describes the width of the saw channel, which is determined by the diameter of the wire, the vibration of the wire and the size distribution of the material particles. Today, a kerfloss between 120 and 160 micrometers per disk 180 micrometers thick is common. Today industrial machines move the wires at speeds between 10 and 20 m / s. In a normal cutting process, therefore, between 300 and 500 km of wire is used. The wires are only used once. Depending on the material, about 0.3 to 0.5 mm is cut per minute. The bars that are cut into slices usually have a size of 15.6 × 15.6 cm.
Research in the network
In the joint project “Kerfloss”, high-performance saws are to be developed with which sawing loss can be reduced by 50%. Participating companies are: Deutsche Solar AG, PV Silicon AG, ASI Industries, the Fraunhofer Institutes for Mechanics of Materials (IWM) and Solar Energy Systems (ISE) as well as the VDEh Institute for Applied Research (BFI / VDEh). The project started in 2006. By 2008, it could be proven that cutting wires with a thickness of only 100 micrometers or even only 80 micrometers are industrially feasible, which would reduce the kerfloss to 108 micrometers. The BMUB funded the project with 1.7 million euros.
literature
- Fraunhofer Institute for Mechanics of Materials (Rainer Kübler): Increasing the use of resources in silicon solar cell technology by reducing sawing loss (Kerfloss) , Freiburg 2009
- Gerhard P. Willeke and Eicke R. Weber: Semiconductors and Semimetals (Vol. 92) - Advances in Photovoltaics: Part 4. Fraunhofer Institute Freiburg, Elsevier Inc. 2015, digitized