IPC - Association Connecting Electronics Industries
Scope
Purpose: This test method covers procedures for determining the electrical resistivity of copper foil. It provides for an accuracy of ?? 0.30 percent of test specimens having a resistance of 0.00001 ohm (10 microhms) or more. Definition: Resistivity is the electrical resistance of a body of unit length and unit cross-sectional area or unit weight. Volume resistivity is commonly expressed in ohms for a theoretical conductor of unit length and cross-sectional area; in English units in ohm?Ccircular mil/ft and in metric units in ohm?Cmm2/meter. It may be calculated by the following formula: p. = A L R where: p. = volume resistivity in ohm?Ccircular mil/ft or ohm?Cmm2 /meter@ A = cross-sectional area in circular mils@ or sq mm@ L = gauge length@ used to determine R@ in ft@ or m@ and R = measured resistance in ohms. Weight resistivity is commonly expressed in ohms for a theoretical conductor of unit length and weight. The method for calculating weight resistivity@ based on resistance@ length@ and weight measurements@ of a test specimen is given in Note 2.