Testing prodn. mass of coated wafer material - by weighing and comparing with reference to control coating thickness

摘要

An arrangement monitoring final mass values of wafer material output from a wafer material coating machine facilitates the maintenance of uniform wt. without additional work and with full material utilisation. This is achieved using a comparison of desired and achieved values in a series prodn. set-up. The coating material is applied by a roller in a head with a manual coating thickness adjustment. The mass values are measured by random weighing. Automatically measured end mass values obtained using a weighing cell are fed to an electronic controller with an identity value. The measured values are compared with preprogrammed limit and a control value produced. Two adjuster devices are used. One drives the thickness adjuster directly. The other drives a conveyor via a continuous gear.