METHOD FOR MEASURING THE THICKNESS OF MULTI-LAYER FILMS

摘要

Measuring the total thickness or individual thicknesses of a multilayer film comprising layers of different nonconductive materials comprises using the measured values from two sensors operating according to different measuring principles to determine a correction for at least one of the sensors, and determining the correct thickness from the measured value from one sensor and the correction for this sensor for at least one subsequent measurement. An independent claim is also included for correcting a series of thickness measurements performed on a multilayer film comprising layers of different nonconductive materials with a first sensor by using a second sensor that gives a different reading for the same thickness of the same material, supplying the signals from the two sensors to a computer, which determines the correct thickness from the different readings and calculates a correction profile from the ratio of the correct thickness to the values measured by the two sensors, and using the correction profile to correct one or more subsequent series of measurements.