Instrumentation and standards for testing static control materials

The design and performance of instrumentation for quantitative measurement of static charge dissipation, with time scales down to a few tens of milliseconds, are discussed, along with the use of such measurements for assessing materials and practical surfaces. The present approach provides the basis for measurements which both cover the range of values of practical interest and do this in a way which is suitable for standardized measurements. It is proposed that materials for use in proximity to sensitive semiconductors should be static dissipative, with decay time constants from a surface potential of 100 V between 10 and 500 ms. The 10 ms lower limit is to avoid risks of spark-type electrostatic discharges on the surface, and the 500 ms upper limit is adequately short compared to normal manual actions likely to cause triboelectric charging.<
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