There are applications that place high demands on capacitors: in machine tool manufacturing, for example, vibrations, mechanical shocks, oscillations and resonances from the circuit board affect the components. To avoid field failures under these conditions, both manufacturers and developers must think carefully and ahead. Two important aspects must be considered, especially when larger electrolytic capacitors are to be installed, which represent a considerable flywheel mass due to their weight alone and, in the worst case, interact with the circuit board:
Mounting of components
Considerations regarding component mounting are usually the responsibility of the development department. The capacitors must be fixed to the circuit board or in the housing in such a way that the connections are not exposed to mechanical stress. If the components are to be glued, thermal heat dissipation and precise attachment must also be carefully checked, because even a well-glued heat-shrink tubing does not necessarily fix the can in place in the long term! It is also important to analyse the installation position carefully, as axial and radial forces have very different effects on the component (vibration modes).
Layout of the components
The manufacturer must optimise the entire internal construction of the component so that it can withstand even the toughest mechanical loads. This is because the winding of the cell inside the component is not a press fit to the housing – mechanical shock can cause the cell to move. In addition, the winding dries out over its service life – it shrinks slightly and its weight is reduced, which shifts the mechanical resonance frequency over the service life. This means that even components that performed perfectly in the test field can exhibit completely different vibration behaviour after two years. The aim is therefore to prevent any movement of the inner winding in order to prevent the connections from breaking and thus a total failure.
In the component optimisation process, it is therefore useful to ask the following questions:
· How thick (=break-proof) are the films?
· Can the number of connections inside be increased in terms of stability?
· Are extra layers of paper useful for protection?
· How are the inner cells fixed in relation to the can?
Conclusion
When components are required that will be exposed to high mechanical stress, it is essential that developers and manufacturers engage in targeted dialogue at an early stage and discuss the issues of fixing and layout in detail. This is the only way to agree on the right precautions when designing the components. Jianghai has decades of experience in the field of extreme mechanical demands. The secret superpower of our technical sales team is to take on the challenge – true to the motto ‘Jianghai: Smart capacitor solutions for your application!"
Take benefit of our expertise to ensure your products are successful in the field!
If you have any questions, please do not hesitate to contact us:
Ole Bjørn
Tel.: 0049 / 2151 / 652088-0
Email