Electronic Connector Contact Lubricants: The Polyether Fluids

The results of a search for connector contact lubricants which have higher service temperatures than a widely used fivering polyphenylether (5-PPE) fluid are reported in a companion paper and continued here. Comprehensive studies of the mechanisms of lubricant depletion and their applicability to fluid coatings were made. They show that the maximum service temperature to which contacts with a coating from a 0.5-wt% solution of the 5-PPE in a volatile solvent, such as 1,1,1trichloroethane, may be continuously subjected is about 30-50°C assuming a product life of 20 years. The temperature limit depends on the configuration of the connector and the criterion of failure. A 2.0-wt% coating of the 5-PPE can be used at 40-60°C. A 2.0-wt% coating of a sixring polyphenylether (6-PPE) fluid has an estimated maximum service temperature of 85-110°C at the same conditions. Furthermore, it is effective at temperatures below 0°C, which is less than its pour point. Low-volatility viscous perfluoroalkylpolyether (PFAE) fluids are good lubricants but can be depleted by surface migration, unlike the PPE's which are nonwetting, and may contaminate surfaces adjacent to the connector. They are therefore less desirable than PPE's. It is recommended that a 2.0-wt% coating of 6-PPE be used when a connector contact lubricant having a broad service temperature range is required. The 5-PPE is not an ideal lubricant for long-lived applications much above room temperature but is effective within its lower maximum operating temperature limits.