Summary matrix of the types of metallization:
Types of metallization
- 1. Constant Resistance
Metallized layers with constant resistance can be made with purest aluminium or zinc with a variable share of aluminium. Our process is capable of evaporating even large areas with an evenly distributed metal layer with the help of mathematical simulation models.
- 2. Heavy-edge (RV)
"Heavy-edge" is the classical solution to enable a stable and low resistive contact to the end-spray (shoop) of the capacitor.
We offer a wide range of choices regarding the metal ratio between the surface resistance of the heavy-edge and the active area.
- 3. Profile Metallization, Wide Heavy-Edge
The best possible compromise and optimisation on low electrical losses and high break down voltages can be achieved by combining a wide heavy-edge with high Ohms on the surface at the free margin side. A wound capacitor must always have one of the two films with a good self-healing behaviour using a high resistive area; typically 1/3 low resistivity and 2/3 high resistivity are designed over the film width.
In collaboration with our customers we precisely define the resistance profile by a drawing.
- 4. Profile Metallization, soft transition, linear resistance
Metallization, with a defined profile of the surface resistance (= Rs), allows the minimisation of the losses at each and every single point inside the capacitor (Pr = I² Rs).
During the design phase the tan. δ, self-healing and breakdown voltage can be rated and optimised mathematically. A profile drawing with the precise resistance profile will then be provided to our customer.
The sketches symbolise the metallized layers of aluminium (yellow) and zinc (red). In the profile drawings provided by us the surface resistance is normally illustrated reciprocally.