Atmospheric potting & vacuum potting

Potting under atmospheric conditions is used wherever the component geometry permits and where absolute bubble-free encapsulation is not critical to reliability. This method is particularly suitable for applications such as protecting components with silicone gel against vibration.

Thorough material preparation is a key factor for successful potting under atmospheric conditions. The potting material must be properly mixed, degassed, and, if necessary, heated to ensure optimal results.

The Atlas Copco Scheugenpflug solution offers the best material properties thanks to homogenization, degassing and temperature control. This combination provides the basis for optimal flowability of the potting materials, leading to shorter processing times and reliable dispensing.

The Scheugenpflug LiquiPrep LP804 material preparation and feeding system is specifically designed for the efficient processing of liquid dispensing media. Combined with a single piston dispenser or a multi-nozzle setup for peak performance, it delivers high output in a compact footprint.

Why vacuum potting? Vacuum potting is the method of choice when component geometry presents challenges such as undercuts, angled surfaces and extremely narrow gaps. It is essential when potting plays a critical role in ensuring the functionality of critical components such as the sensors used in autonomous vehicles, and when optimum levels of quality, safety, and reliablity are required.

With this method, electrical components subject to heavy load – such as transformers, ignition coils and capacitors – are fully encapsulated in casting resin to protect them against heat, moisture, vibration, and dirt. This enhances their durability, reliability, and performance. Depending on the application, resins also improve mechanical stability, heat dissipation, and voltage or temperature resistance.

To ensure bubble-free application, both the material preparation and feeding process as well as the potting process itself must take place in a vacuum. Vacuum potting of electronic components typically involves reducing the pressure to a maximum of 1 mbar. There are good reasons for this: the lower the reduction in pressure, the longer the evacuation time and the higher the energy costs. The vacuum level is therefore precisely adapted to the specific task. When selecting the optimal vacuum pressure, a balance must be struck between component protection and cycle times.

The important criteria for potting depend on different factors such as the material used, the workpiece design and the curing process selected. The 1K or 2K PU, epoxy or silicone based potting compounds used have functions and properties (color, hardness level, material thickness, temperature stability) that can be tailored precisely to the particular application such as heat dissipation, fire hazard protection or reduce thermal loads.

Before the actual potting can take place, however, it is important to employ a material preparation and feed system suited to the task. To achieve high-quality, reproducible potting results, parameters such as viscosity, temperature, bubble-free application, filler concentration and the reaction of the medium need to be taken into consideration. State-of-the-art systems with heavy-duty feed pumps and sophisticated pressure and vacuum controls provide the necessary reliability.