RF Probe Setup Guide: Video 4: Focus & Planarization
Focus the microscope onto the Contact Substrate. The probe tips will appear out of focus. Then use the z-micrometer on the positioner to lower the probe tips towards the Contact Substrate. The probe tips will begin to come into focus as they move closer toward the surface of the ISS. Evaluate tip contact by gently touching down on the soft gold of the Contact Substrate. As the probe makes contact, the contact force will cause it to move forward. This motion is called ‘skate’. Only about 25 to 30 microns of skate is required to make proper electrical contact. The marks left by the probe on the Contact Substrate should be barely visible and very even.
The probe should be maintained in the microscope's field of view. However, if the probe is not planar then one probe finger may make a deeper mark than the others. This can be seen here where one of the probe’s ground fingers is not able to touch down. The probe positioner planarity control is then used to achieve even marks. Move the other probe into the field of view and follow the same procedure for planarization as before.
Once the probe has been planarized, it should be raised off the surface of the substrate and moved to the side using the z- and y-micrometers respectively.
