Strength of copper wire connections welded by ultrasonic
AbstractThe results of tensile test of ultrasonically weldedconnections of copper wires are presented in this article.The connections differ by the number o wires in the con-nection and also by the combination of wires number at the different sides of connection. The dependence of tensile test results on surface preparation of the wires is settled.When the wires are cleaned from the insulation only me-chanically small fibers of insulation remain on the surface of the wires. Those fibers reduce connection strength. Ad-ditional cleaning of the wires by compressed air before welding increases the strength of connection up to 35 %. The influence of additional cleaning is especially obvious for connections with large number of wires. The analysisof experimental results is done and the dependence of frac-ture force on the ratio of perimeter / welded connectionarea is derived. With reference to the results of tensile teststhe suggestion for quality development of ultrasonic weld-ing of copper wires is proposed.