Microswitch Lifecycle Test Fixture for Simultaneously Measuring Contact Resistance (Rc) and Contact Force (Fc) in Controlled Ambient Environment

The focus of this paper is the development and assembly of a high lifecycle test fixture capable of simultaneously measuring contact resistance and contact force associated with microswitch reliability studies. This novel test fixture incorporates a piezo actuator for precise motion control and a high resonance force sensor for measuring forces in the μN range at cycle rates up to 3kHz. Preliminary tests using this test fixture have demonstrated the feasibility of producing high quality data to support various micro-contact research and have supplied new information for studying force/position and contact resistance/force. Also, upper and lower contacts have been fabricated using MEMS processing techniques which will be vital to the investigation of the mechanical and electrical aspects of contact physics. Finally, a customized fixture for mounting the micro-machined contacts and providing precise alignment of the contacts with the drive and force sensing components has been implemented. This assembly is isolated from externally generated vibrations and is installed in a "dry-box" enclosure to minimize surface contamination. This functionality will enable testing a wide range of contact materials and reliability studies.