Predictive Maintenance for Plasma Cleaner by Using Plasma Monitor

Abstract

Plasma cleaners are used in the assembly process of semiconductors for the purpose of improving wire bondability and improving the adhesiveness of mold sealing resin.

Plasma cleaners produce a less volatile reaction than semiconductor front-end processes in which wafers are plasma-processed, so polymer deposition in the chamber progresses faster. Dirt in this chamber will damage the workpiece being machined.

On the other hand, from the viewpoint of preventive maintenance, it is necessary to perform maintenance according to the progress of polymer deposition in chamber, and since the degree of polymer deposition in the chamber was unknown, the timing of maintenance could not be estimated.

Therefore, we report on a method for estimating the degree of polymer deposition in the chamber using a plasma monitor that measures changes in plasma impedance with an existing sensor required for machine operation.