Plasma Degradation

Description: The o-ring or seal often exhibits discoloration, as well as powdered residue on the surface and possible erosion of elastomer in the exposed areas.

Contributing Factors: Chemical reactivity of the plasma. Ion bombardment (sputtering). Electron bombardment (heating). Improper gland design. Incompatible seal material.

Suggested Solutions: Plasma-compatible elastomer and compound. Minimize exposed area. Examine gland design.

Contamination

Description: The o-ring or seal exhibits foreign material on the surface within the cross section.

Contributing Factors: Process environment deposition. Reactions or degradation of the elastomer. Non-semiconductorgrade elastomer.

Suggested Solutions: Specify contamination level including manufacturing and packaging of the seals.

Abrasion

Description: The o-ring or seal or parts of it exhibit a flat surface parallel to the direction or motion. Loose particles and scrapes may be found on the o-ring or seal surface.

Contributing Factors: Rough sealing surfaces. Excessive temperature. Process environment containing abrasive particles. Dynamic motion. Poor elastomer surface finish.

Suggested Solutions: Use recommended gland surface finishes. Consider internally lubed elastomers. Eliminate abrasive components.