Experimental Investigation and Understanding of the Intermittent Molten Bridge Phenomena and Mechanism of Contacts With Superlow Opening Speed

The molten bridge phenomena of gold-plated material at superlow opening speed conditions are studied by introducing our newly designed test rig. The typical waveforms in the contact voltage and contact force during opening are investigated under the load of 5/25 V at 0.2/0.5/1 A and the speed of 25~150 nm/s. It is demonstrated that the intermittent molten bridge phenomena are resulted from the competition of multitude contact a-spots for current distribution. Furthermore, the measured tension force during breaking closely correlates with the occurred molten bridge. Based on the capillary force model, surface analytical technique, thermal equilibrium principle, and the change in the bridge length and duration, the physical mechanism of the intermittent molten bridge under different load conditions is proposed.