Mask washing system and method

Abstract

A system and method for ultrasonic cleaning of an in-process shadow mask contaminated with polymeric films such as are employed in color cathode ray tube (CRTs) screen production. The ultrasonic bath contains a solution having a chemically active agent for degrading and removing a targeted cross-linked polymer film contaminant from the shadow mask. The cleaning solution may also have more conventional materials in addition to the chemically active agent. The chemically active agent, attacks PVA films contaminating the mask, may be hydrogen peroxide or a periodate. The agents act to chemically degrade the polymeric contaminants. Contaminants are thus removed from the shadow mask during CRT production to reduce clogging of shadow mask apertures and facilitate attachment of the shadow mask to a faceplate-mounted support structure. The very low concentrations of chemically active agents required in conjunction with ultrasonic energy allows for direct solution-to-transducer contact while providing good mask decontamination.

Dependencies are inferred from the claim text.