Development of a high precision through-feed grinder

Hard and brittle thin-plate materials used in fabricating electronic components such as filters and oscillators have conventionally been subjected to a lapping process in order to achieve the required thickness within 1 μm. The lapping process, however, requires an operator's high level of skill; in addition, it is difficult to conduct automatic processing. We have developed double-wheel grinding equipment (through-feed grinder) with the purpose of obtaining the accuracy normally obtained with lapping. This equipment is structured by mounting a magnetic bearing in which a unique microactuator function, specifically developed for hard and brittle thin-plate materials, is incorporated. With continuous processing of the hard and brittle thin-plate materials, a thickness accuracy of ±0.5 μm was achieved from data obtained with on-machine thickness measurement.