How to maintain Auto Insertion and SMT machine — ESD Cleaning and Testing Procedures

Procedures and Adjustments

CAUTION

The following procedures explain how to properly clean and test an ESD surface.

Clean an ESD Surface

Do not use abrasive or highly alkaline cleaners on polycarbonate. Never scrape polycarbonate with squeegees, razor blades, or other sharp instruments. Benzene, gasoline, acetone, or carbon tetra chloride should never be used on polycarbonate. Do not clean polycarbonate in the hot sun or at elevated temperatures.

  1. Using a sponge or soft cloth, wash the ESD-protected surface with either a mild detergent or Windex product and lukewarm water.
  2. After washing, rinse with water and dry thoroughly with a chamois or moist cellulose sponge to prevent water spots.
  3. To protect the ESD surface after rinsing and drying,  recommends applying Kleenmaster Brillianize®. This application helps to maintain the static dissipative coating and reduce the accumulation of dust.

Test Static Dissipative Covers

Periodically and after maintenance, check the machine covers to determine if the dissipative qualities of the cover have changed. The following procedure ensures that static dissipative covers are in fact dissipative.

Tooling

Surface resistance meter (such as 3M 701 Surface Resistance meter and probe).

Comments

The surface resistance should be less than 109 ohms in all areas. If the cover package is no longer dissipative, contact you Universal Instruments Corporation sales representative.

Procedure

  1. Clean the static dissipative covers using the Clean ESD Surface procedure to ensure the accuracy of the test.
  2. Using the surface resistance meter, follow the instructions provided by the manufacturer to measure the surface resistance of both the inside and outside of the covers. Measure the resistance at all four corners and at several areas in the middle of the cover. This test checks the integrity of the ESD coating.
  3. Connect the ground path resistance probe to the meter and chassis ground.

The path to the ground should not be higher than the surface resistance. If it is, clean the frame connections, repair loose or corroded fasteners and ground straps, and check tracks for dirt and/or corrosion.

4. Measure the ground path from the covers to the chassis ground. Take this measurement from both surfaces and all four corners of each cover.