Testing Silicon Wafers

The base plate of the cell is a silicon disc. The importance of this component coupled with constant material reduction necessitates strength tests, for which the established  4-point flexure test is used with a special SI wafer holding-device. However, high localized pressures are generated during this test. By contrast the 4-point flexure test with linear anvil enables virtually constant pressure-distribution and is frequently used to eliminate differences in quality between suppliers. Additional information on the manufacturing quality of the wafer is obtained using the double-ring flexure test. The measured maximum bearing-load of the wafer is influenced by its edge condition, thus providing a measure of its quality. These tests require forces up to a maximum of 30 N and can, for example, be carried out using a zwicki-Line materials testing machine. This machine’s compact design makes it ideal for integration into production lines.