Reuseable mass-sensor in manufacture of organic light-emmiting devices

摘要

A method for controlling the deposition of an organic layer in making an organic light-emitting device includes depositing at a deposition zone organic material forming a layer of the organic light-emitting device and providing a movable sensor which, when moved into the deposition zone and is being coated during the depositing step, provides a signal representing the deposition rate and thickness of the organic material forming the layer. The method also includes controlling the deposition of the organic material in response to the signal to control the deposition rate and thickness of the deposited organic material forming the layer, moving the movable sensor from the deposition zone to a cleaning position, and removing organic material from the movable sensor to permit reuse of the movable sensor.