Pull test overview:
Tensile testing of thin and large wire diameters
Manual and automatic wire pull tests
Test Leads and Ribbons
Vector pull test
Destructive and Non-Destructive Testing
Wire pull testing is used as a process control method for determining primary and/or secondary bond adhesion. Ideally, the wire should break mid-span when pull tested, but loop height, splice quality, splice method and, to a lesser extent, operator or hook type can all affect test results.
The principle behind a basic wire bond pull test is to position a hook under the wire and pull it along the Z axis until the bond breaks (destructive testing) or a predefined force is reached (non-destructive testing).
Pull tests are at:
Fine wire diameter (typically 12.5 to 75 microns)
Large wire diameter (typically 100 to 500 microns)
Ribbons (typically up to 2000 x 250 microns)
Pull test boxes can cover a range of pull forces and allow for destructive or non-destructive testing. Appropriate hooks should also be used, in the case of wire bonding, the hook should be at least 2 times the diameter of the wire under test.
The vector line pull test simulates a perpendicular test angle between two bonds when the surface height of each bond is different. This is achieved by coordinating the XY and Z axes of the wire pull Tester, so the test is performed at the desired optimal angle.
Small geometry (ultra fine pitch) applications are becoming more and more popular, so Nordson DAGE offers wire pull test equipment specifically for this function.
Pull wire tests can be performed manually or semi-automatically according to pre-programmed test programs.
