Potting compounds are a general-purpose types of sealant that can offer environmental, mechanical and physical protection to circuit boards and electronic assemblies. Used in electronics, potting is a process of filling a complete electronic assembly with a solid or gelatinous compound. The potting compound, once applied, cured and hardened encases your electronics in a solid mass providing a barrier which provides protection from moisture, vibration, thermal or physical shock and general contamination. The mechanical protection enables the components to maintain high performance under extreme conditions. Thermosetting plastics or silicone rubber gels are often used.
Types of compounds
Epoxy Potting Compounds - Epoxy potting compounds generally perform as a better adhesive, high temperature resistance, and chemical resistance. Epoxy systems have better adhesion to a wide variety of substrates and typically do not need primers. They are easy to use and are predictable. They have good high temperature resistance up to 400°F.
Urethane Potting Compounds - Urethane potting compounds generally have better flexibility, elongation, and abrasion resistance. Since they can have Tg below -40°C they are an excellent selection for SMT PC board potting. Their gel time can be easily changed with an accelerator without changing the properties.
Silicone Potting Compounds - Silicone potting compounds and encapsulating materials are also soft, flexible, and have better elongation. Silicone materials also provide the widest operating temperatures. Specially formulated silicone potting compounds can operate at below -100°C and most silicone materials can handle 200°C temperatures.
Acrylic Potting Compounds - Acrylic potting compounds are UV and heat hardening materials. They benefit from very fast hardening, adequate chemical resistance and are clear in appearance.
Applications of Potting Compounds
Potting compounds are used in a range of applications such as;
- Automotive industry