The lifetime and reliability of insulation displacement contacts with solid and stranded wires

To determine the lifetime and reliability of insulation displacement connections with solid and stranded wires for use in telecommunication equipment, dry heat tests at 100°C and 70°C were carried out. The duration of these tests was up to three years. Temperature cycle tests between 20 and 80°C were also made. The increase of the contact resistance in these tests is compared with the resistance increase of connectors kept at laboratory conditions. Both solid wires (0.5 and 0.4 mm) and stranded wires (7×0.20 mm, 7×0.16 mm, and 18×0.10 mm) with and without tin plating were tested in insulation displacement slots of three different manufacturers. It is found that the slots tested with solid wires have a stable contact resistance, while some of the slots with stranded wires showed an increase of the contact resistance. This was strongest for the 18-strand wires. The test results are compared with the spring constant and springback of the insulation displacement slot. Criteria for the evaluation of the lifetime and reliability of insulation displacement connections are discussed