IDC connector producers set the requirements on wire insertion procedures and quality of the connector termination which must be observed by the cable harness producers. Only if all the specifications are met, the connector producers will guarantee the quality of the final product.
However, no standard was set how to measure the quality of the wire insertion effectively during the production process nor what equipment to use for such measurement. Additionally, parameters requested by the connector producers may vary at least (or even contradict from one to another), despite they all need to comply with RAST standards.
It is impossible to verify all the parameters set during the production process. Therefore, it is crucial for the cable harness producer to test and identify how the conformity with one requirement impacts the other parameters set. In this thesis I have analyzed the requirements of R2,5 IDC connector family set by Stocko connector producer on wire insertion, defined the activities in the production process and proposed the optimization procedures related to the quality control testing.
In Cablex Group, we have defined very detailed and strict quality assurance procedure in order to meet the requirements set by the connector producers. However, due to significant production volumes, rapid expansion of the production abroad and the magnitude of the testing procedures, not all of them could be implemented in practice. As such, one of biggest challenges that we face now in production is related to the improvement of the control environment and implementation of such controls that are effective and cost efficient.
I have investigated the possibility of simplification of the existing quality assurance procedures and identified quality controls that were unnecessary and did not bring additional value in ensuring the quality of the final product. The changes proposed to the current quality assurance procedures are based on the testing results related to vertical wiring insertion depth, pull-out forces, micro-graph section analysis and measurements of the gaps between contacts.
All tests were performed on R2.5 Stocko connectors, for three different wiring insertions, which are most commonly used in our production. In order to validate the quality of the measuring methods used I have finalized a sample of connectors which were in and out of the tolerance levels specified (in terms of their vertical depth insertion) and measured how the performance of the connector joint was affected. I have particularly focused on the requirement related to pull-out forces, which are not predefined by Stocko, but most of the other connector producers. I was also interested in correlation among the requirements and whether the conformity of one parameter could lead to adherence of others. For this reason I exposed the samples also to deterioration and measured its impact on voltage and overheating.
Based on the testing performed, there seem to be no connection between pull-out tests and product conformity. Therefore this method (by which a large number of finalized connectors are destroyed during testing) is unnecessary. Vertical wiring depth, on the other hand, proved to be the critical element that determines the quality of the terminated connector. Vertical wiring insertion depth measurement in connection with visual inspection of the materials used, including the wiring-end position (horizontal depth) present sufficient information to determine whether the quality standards were met in the production process. More detailed and complex measurements in the laboratory can be therefore separated from the production line testing and performed periodically on selected sample size basis.
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