Technology of „Press-Fit” Connectors
The press-fit technology is a special bonding method of assembling printed wiring boards, which can substitute the Through Hole soldering technology. The method is mostly used for connectors. In the process, the coupling pin is pressed into the metallised hole thus, forming an electrically conductive and mechanically stable joint.
The main goal in my project was to realise a press-fit component placer tool, which can serve a small-volume serial production suitable for laboratory and educational purposes in the Budapest University of Technology and Economics, Department of Electronics Technology providing a low cost alternative of expensive industrial large-scale equipment.
In order to get the thorough understanding of the press-fit technology and fot the successful implementation of the mounting tool, in addition to the literature research I studied the equipment used by industrial partners of the Department of Electronics Technology.
For my experiments, I selected various types of press-fit components. I designed test boards, where I enabled the direct measurement of the contact resistance between the connector’s pin and the hole metallisation, as well as their measurement in daisy-chain connection.
I measured the pressing strength over time. I determined the maximum strength on the basis of the force versus time curve, calculated the average for each type connector, as well as I determined the necessary average force for a single pin. Component pullout tests were also executed for the joint qualification.
I made cross-sections from the implemented press-fit connectors. I have examined the structure of the bonding in microscope and electron microscope images.
The results of my diploma led to a major step towards installing the press-fit technology in the laboratory for small series production purposes.