Specialty Metal
Films Co. is ITARS registered.
Frequently Asked Questions
Our windows require optical coatings on both sides.....do they go on before or after your metals?
We can do it either way, however it is more common for the metal solderband coatings to be applied
after the optical coatings, mainly to ensure that the metals remain pristine.
Can
you apply the metals directly over the optical coatings?
They can be, depending on the
composition of the optical films, but a much more reliable hermetic seal will be made if the metals are deposited directly
onto the substrate material. The optical coating process normally requires a "tooling land area" around the
perimeter of the window which will be free of the coatings, so this is rarely a problem. If the top layer of the optical stack
is MgF2, SiO, or SiO2, then we can bond to these materials as well as we bond to the substrate material, however, if the top
layer of the stack is one of the Zinc compounds, then we do not recommend applying metals over this material. One way
or another, we always do a test run, to be certain.
We need the
edges of our windows metalized, as well as the top surface perimeter......is this a problem?
Not
at all, but you need to make us aware that this area is critical to your sealing process, as we need to take some special
measures to make sure that you get good coating quality on the vertical edges of your windows.
Can
we have our windows coated on three sides, top, bottom, and edge?
Yes, but this option
should be considered carefully as it adds significantly to the cost of the metalizing process, as well as adding a LOT of
extra handling.........more handling always means potential cosmetic damage to the optical coatings.
How hot will our windows get during the metalizing process?
Not to exceed 75°
C
What is the maximum temperature that these films will survive?
450-500°C, but we have a recent report from a customer who has taken them to brazing temperatures (800C+) without
failure.......yes, that surprised us too!