Experimental study on the process of cleaning the contacts of signal control relays

The authors carried out a study of the effect of organic materials on contact resistance, taking as a typical contamination source paraffin hydrocarbons, which are the most general kind of contact contaminant and are used in the various machines in the manufacturing processes, to clarify the problem of contact reliability caused by contamination by organic materials during the manufacturing process. In addition, the authors also studied conventional methods of contact cleaning as well as cleaning methods that could conceivably be used instead of conventional methods. As a result of this study, it was found that, even when the thickness of organic membranes was around 100 AA, the contact resistance increased along with the passage of time. This trend was particularly prominent at the normally open contact side. The authors also found that alternate methods of removing these organic films, such as CO/sub 2/-laser cleaning, were quite effective.<>