Hoechst Aktiengesellschaft

Michael Roethe

Klaus Horn

Georg Sader

Hans-Joachim Schulz

To produce a standard calibration and test element for the calibration and testing of reading and measuring instruments for bar codes and other test scales, a copper coating is applied to a ceramic substrate in a chemically depositing copper bath and degreased, and a photoresist coating is subsequently applied which is exposed through an exposure mask. This mask carries an image of the radiation-transparent and radiation-opaque regions of a pattern to be transferred onto the surface of the ceramic substrate. After removal of the mask, the photoresist coating is developed, the uncovered zones of the copper coating are etched in a metal chloride solution, and the remaining photoresist coating is removed by stripping. The uncovered, etched zones of the copper coating are dyed matt black in a metal bath. Finally, the conductive tracks are provided with a protective coating. The standard calibration and test element produced in this fashion comprises a ceramic substrate 1 as a carrier which contains a proportion of 96 to 97% of Al.sub.2 O.sub.3. The thickness of the element is 0.635 to 1.270 mm and the dimensions can extend from a 20 mm edge length to a size of 100.times. 100 mm.

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Wiesbaden, Germany

Michael Roethe