Thermal expansion coefficient between 20 and 100°C:
0.8 x 10-6/K ≤a ≤1.6 x 10-6/K
The tension annealed material is recommended for etching or photochemical machining processes and for operations at elevated temperatures, where dimensional stability is essential for the production of patterns or components.
The patterning of masks is usually carried out by a photochemical etching process, during which material is removed to produce through apertures. In order to maintain the desired shape and tolerances after the etching process, internal stresses must be minimised. Furthermore, the low thermal expansion and its tight control allows the use of Zapp SuperClean Invar36 over a large temperature range, even in combination with other materials.
The shape accuracy of our superclean Ni36 precision foils is such that periodical patterns below 30 micrometre can be produced by photochemical machining. The combination of our know-how and modern equipment enables us to produce excellent flatness and tight tolerances.
Zapp SuperClean Invar foils are essentially free from waves and at the same time internal stresses. For very precise micro-patterns our metallurgists have developed special metallurgical routes with our suppliers to meet the highest demands. In addition, to the standard metallurgical routes we have access to refined melting processes such as electro slag remelting (ESR) and vacuum arc remelting (VAR) with improved cleanness. For special applications we can offer our even cleaner Zapp SuperClean material for patterns down to a few microns. With respect to very small inclusions the material is significantly cleaner than remelted material. This is essential for the production of very small apertures.
DATASHEET ZAPP SUPERCLEAN INVAR FOILS
Brochure Ni36 – Etching and Laser Cutting Applications