During micro wire bonding , an electrical contact building process is known in the electronic technology the bonds are made by different methods (ultrasonic vibration, thermocompression or their combination). This is a well known surface mounted technology since decades.
My project was to compare the results of the FEM simulation of pull test with the values from literature and laboratory measurements.
Through information from the literature and my own measurements the following assumptions have been made on the pull test:
Thoose bonds had the worst quality which were made on copper contact surface. The quality of bonds were better when I used gold and silver instead copper. The bonds were made in an other laboratory had the best quality, bacause the break were always in the middle of the wires.
I made simulations not only in the standard vertical direction, but also in the range of 0-45°. These simulations were made about the bonds of the silver surface and the other samples of the other laboratory which are considered ideal.
About the simulations I have got the following experience: The pull in the different directions (range of 0-45°) does not have significant effect on the place where the wire is broken and the magnitude of force which destructs the wire.
Furthermore I examined the magnitude of force which destructs the wire with hooks with different diameters. I have got the results, that the break of wire with bigger hook diameter needs bigger force.
In the future the results on your own my simulations could be reproducted and plot the stress through the wire during nondestructive pull test. It could be give more accurate informations about these quality test.