A HICON success story.


EBNER.blog | Leopold Fellinger & Manoj Kumar, EBNER

A HICON success story.

Extremely thin aluminum foils, annealed in extremely pure atmospheres: products for special applications in the electronics industry.

The worldwide success story of EBNER high-convection bell annealer technology has been extended with the addition of yet another application. Over the last few years, EBNER has successfully installed several facilities designed to produce aluminum foil for the electronics industry.

For this special application, many well-known manufacturers supplying the electronics industry can be counted among EBNER’s customers. The end products find many uses, for example in capacitors, micro-electronics and (more recently) battery technologies for electric vehicle applications.


The requirements placed on the aluminum foil, for example high-capacitance foil, are extremely high. Significant aspects include electrical conductivity, quality of surface finish and resistance to oxidation, all of which must be combined with excellent mechanical properties.

To manufacture capacitors, extremely thin aluminum foil is used as both anode and cathode. The surface of the anode is coated with a “thick” layer of oxide, which acts as a dielectric. The oxide layer is created in a downstream process, referred to as anodizing. This requires the natural oxide layer to be both thin and evenly distributed, which in turn requires a very precise and evenly-distributed heat treatment process in an extremely pure atmosphere.

Along with the purity of the atmosphere, precise temperature control is a fundamental requirement. Both of these requirements can be fulfilled by EBNER’s proven HICON annealing technology. The heart of every bell annealer facility is the EBNER HICON workbase, with its high-convection recirculation fan. The fully gastight design of the workbase enables a “high” vacuum to be achieved, which is essential for certain process steps. The extremely pure atmosphere is supported by the use of argon as a process gas.

Through the use of a 3-stage vacuum pump, a vacuum of 2 x 10-3 Torr can be achieved. This is only made possible by the extreme precision with which workbases are manufactured in our in-house workshop. Before it is shipped, every workbase undergoes extensive quality testing – including vacuum testing in our lab.

The precisely-distributed flow of atmosphere through the charge ensures that even the most severe requirements placed on the temperature uniformity within the aluminum coils can be achieved.

Throughout the world, a wide variety of customers rely on proven EBNER technologies to heat treat aluminum foil for the electronics industry. EBNER is proud to be the global leader in this special market segment.

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