Method and apparatus for determining the surface topography of coated reflective surfaces
View Patent ↗The invention relates to the field of measurement technology and concerns a method and an apparatus, such as may be used, by way of example, in thin-layer technology for organic dielectric semi-conducting or conducting layers on substrates. The object of the invention is to indicate a method and an apparatus with which both the surface topography of the coating and that of the surface may be determined independently of one another, at the same position. The object is achieved by a method wherein the three-dimensional topography of the coating is determined using chromatic white light measurement and, subsequently, the thickness of the coating is determined using UV interferometry, and the surface topography of the coated surface is determined by a comparison with the overall dimensions of the coated surface. The object is further achieved by an apparatus wherein an apparatus for chromatic white light measurement and an apparatus for UV interferometry are disposed on a test bench.
1. A method for determining the surface topography of a substrate underlying a coating, comprising:
determining a three-dimensional topography of the coating on the substrate using chromatic white light measurement by making surface height measurements at x-y coordinates,
determining the thickness of the coating at said x-y coordinates by making coating thickness measurements at said x-y coordinates using UV interferometry, and
determining the surface topography of the substrate from results of said surface height measurements and said coating thickness measurements.
2. The method according to claim 1 , wherein the substrate is a glass or polymer substrate, and the coating is a metal coating.
3. The method according to claim 1 , wherein the coating comprises a non-crosslinked or crosslinked polymer layer.
4. The method according to claim 3 , wherein the coating comprises a bisphenol-A based epoxide&, polystyrene or polymethyl methacrylate.
5. An apparatus for determining the surface topography of a substrate surface underlying a coating, comprising:
a surface height measurement apparatus for making chromatic white light measurements of a surface height of said coating at x-y coordinates, and
a thickness measurement apparatus for making UV interferometry measurements of the thickness of said coating at said x-y coordinates,
wherein said surface height measurement apparatus and said thickness measurement apparatus are both located at one measurement station.
6. The method according to claim 1 , wherein said surface height and layer thickness measurements are made using respective sensors at one measurement station.
7. The apparatus according to claim 5 , wherein said surface height measurement apparatus is a confocal scanning apparatus.