System for performing contact angle measurements of a substrate

A system for positioning a substrate having a surface required to be characterized with a contact angle measurement, the system comprising:

• a stage which supports the substrate;
• a dispenser assembly having a dispensing tip through which a liquid droplet having a preselected volume is dispensed onto the surface of the substrate;
• a first stepping motor mechanically coupled to the stage with a lead screw to move the stage in a horizontal direction;
• a second stepping motor mechanically coupled to the stage with a belt and capstan mechanism to rotate the stage;
• a third stepping motor mechanically coupled to the stage to change the vertical spacing between the dispensing tip and the surface of the substrate;
• a fourth stepping motor mechanically coupled to the dispenser assembly to dispense the liquid droplet from the dispenser assembly;
• and
• a controller which delivers actuation signals to the first, second, third, and fourth stepping motors, so as to place the liquid droplet at a predetermined location on the surface of the substrate for performing the contact angle measurement.