Encapsulation Material
Protective compounds used to seal electronic assemblies are selected based on their mechanical flexibility and chemical resistance. The process of polyurethane potting involves dispensing a two-part liquid resin that cures into a semi-rigid or elastomeric barrier over the components. This compound is chosen when the assembly requires protection from moisture and mechanical impact without generating high curing stresses.
The material adheres well to a variety of substrates including plastics, metals, and circuit boards.
Moisture Protection
Water ingress can cause short circuits and corrosion in outdoor sensor installations. Using polyurethane potting creates a tight, hydrophobic seal that prevents the penetration of water and moisture vapor into the sensitive electronics. This chemical barrier maintains the electrical insulation resistance of the circuit under humid conditions.
Mechanical Cushioning
Vibration and mechanical shock can damage delicate surface-mount components and solder joints. The elastomeric nature of polyurethane potting absorbs these dynamic stresses, protecting the internal components from fatigue. This makes it suitable for sensors mounted on heavy machinery or automotive chassis.
Thermal Limitation
High temperatures can degrade these polyurethane materials when they are exposed to conditions above one hundred and twenty degrees Celsius. When this degradation occurs, the polymer loses its protective properties and can release moisture back into the circuit.
