The first part failed for CR max at 95 m[ohm] and RDEL at 25.
All of these parts meet the manufacturer's specifications: however, they all have high RDEL, high twist resistance, or both.
This part had high CR and RDEL values of 44 m[ohm] and 5 m[ohm], respectively, on the failing (normally closed) contact.
The RDEL population had 10 failures, with nine occurring before 100 million cycles.
All failed parts were removed from the test at the point of failure, and the CR and RDEL readings for these parts were recorded at that time.
All failing devices also show a high degree of contact instability in the RDEL readings, with readings ranging from 37 m[ohm] to several ohms.
From this plot, a dramatic difference can be observed for the B1 and B10 failure rates between the Accept population and the Twist and RDEL reject populations.
100 cycles for the Twist population and approximately one cycle for the RDEL population.
From the life test study, early life failures occurring before 100 million cycles would account for half of the Twist and RDEL rejects.
Two very simple parametric tests called Twist and RDEL can accurately predict parts that will fail prematurely.
The RDEL test is performed at nominal coil voltage and looks for instabilities related to chemical contamination in addition to poor alignment and rough contact surfaces.