Bubble trouble? Vacuum potting could be your answer
Air has no business being inside an electronic component. It can cause corrosion, impair heat dissipation and, in a worst case scenario, lead to short circuits and fires. The consequences can be serious, especially in safety-critical applications such as those in the automotive industry. Vacuum potting is the answer.
Why vacuum potting?
Increasing demands on quality, more and more complex component geometries and ever greater freedom of design are making the potting process more challenging than ever. Electronic components have to function reliably throughout their entire life cycle – whether in a car door handle, in a coil or in the power electronics of an electric vehicle.
Sensitive electronic components such as populated PCBs and power modules must be reliably protected against chemical, corrosive and mechanical influences. Reducing thermal stress, dissipating heat efficiently and protecting against fire hazards also play important roles.
“Vacuum potting is the method of choice whenever optimum levels of quality and safety are required. And if it is to be done efficiently and in series, there is no other option than a multi-nozzle dispenser. Our multi-nozzle dispensing systems achieve bubble-free potting with maximum cycle times – even under vacuum conditions – combing speed, economy and quality in a single process.”
Sebastian Nadler Technical Sales
Vacuum potting: A clear solution for complex shapes
Homogeneous and bubble-free potting of components in a vacuum chamber of the productline Scheugenpflug
1K or 2K potting compounds based on polyurethane (PU), epoxy resin or silicone are used, and these can be precisely matched to the particular application in terms of color, hardness, density and temperature resistance.
No bubbles – better safe than sorry
The vacuum removes air from the components. The potting material is dispensed directly into the component, enclosing the sensitive electronics and thus ensuring that no air bubbles remain in the material. This is crucial because even the smallest bubble can be conductive – and especially critical for coils in which the wires are extremely thin and close together. A single bubble between them can have fatal consequences.
Getting the preparations right
These problems can be avoided by potting under vacuum. But it requires careful preparation.
- Tempering the material: The material has to be preheated and homogenized to achieve the desired viscosity.
- Getting the pot time right: High temperatures shorten the processing time, so there is a balancing act between flowability and curing.
- Preventing bubbles from forming: Air pockets must eliminated by stirring and degassing even before potting begins.
When is vacuum potting the method of choice?
- When there are complex geometries with undercuts
- When there are safety-critical application
- When there are sensitive windings (e.g. coils, transformers)
- When optimum reliability and service life are required
Complex parts like transformers and coils in front of a vacuum chamber
Vacuum potting is not a simple process – but it’s the right one if absolute safety and optimum quality are the priority.
So dare to try it – it will be worth it.
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