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Application Examples |
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Protective Lacquer Coatings |
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Click on the image
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Film thickness
measurement of dry or even wet lacquer coatings, with the possibility of a simultaneous
two-layer measurement. Our technology is used by the world's leading manufacturers of Automobile
Headlights and Compact-Discs.The picture shows a 3D film
thickness profile of the protective lacquer of a standard commercial Compact-Disc in the
range of 9-13 microns. |
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Vapor Deposition
(e.g. Parylene) and
Photo Resist
Layers |
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Click on the image
for a large picture |
The highly precise
technology of our thickness gauges determine the film thickness of even sub-micron layer
structures. The picture shows a 3D film thickness profile of a 10 mm² diamond layer on
silicon in the thickness range of 800-1000 nanometers. |
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Web Coating of Wrapping Foils
and other |
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Click on the image
for a large picture |
The film thickness
profiles of web produced or coated foils can be determined in cross- and/or
machine-direction by using a scanning bridge and our film thickness gauges. This permits
an intermediate feedback for your process and production control. The picture shows a
schematic gauge setup for film thickness measurement on a web coating or foil machine. |
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Measurement Method
Principles |
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A
commonly well-known effect, which occurs for example with soap bubbles or on a thin oil
film on water, is used for the determination of the film thickness. You can see many
colors which change according to the layer thickness, e.g. when a soap bubble is blown up.
Also check out this Soap Bubble Web site for some
nice pictures and more detailed explanation of this effect!
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These
"colors at thin layers" are based on the interference phenomenon, i.e. on the
superposition of light waves, which have been reflected at the front and back side of the
layer (at two boundaries with different optical densities). |
The Interference Model |
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The undisturbed
superposition of the two reflected light rays 1 and 2 leads to periodical amplifications
and extinction in the spectrum of a white continuum light source (such as a halogen
spectral lamp as a pseudo white-light source).
Since the superposition of the two light rays is not purely additive, a so-called
interference occurs. The figure at the right shows the interference spectrum of a 1 µm
(top) and a 2 µm (bottom) layer.
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Examples of Interference Spectra |
