Potting glue is also called electronic AB glue, electronic potting glue, AB potting glue, and two-component potting glue, the main function is bonding, sealing, potting and so on. Potting glue is often poured into devices containing electronic components or circuits by mechanical or manual methods, and cured under normal temperature or heating conditions to become thermosetting polymer insulating materials with excellent performance. This process is called "potting". Potting can play an important role in moisture-proof, dust-proof, anti-corrosion, shock-proof and waterproof for electronic and electrical components, and improve the performance and stability parameters. The potting glue is liquid before curing, with fluidity and viscosity. It varies according to the material, performance and production process of the product.
From the material,
it can be divided into silicone potting adhesive, polyurethane potting adhesive
and epoxy potting adhesive; from the curing conditions to divide, it can be
divided into two kinds of room temperature curing and heating curing; in light
of the agent type, it can be divided into two-component and one-component two
kinds.
Advantages: After curing, the silicone encapsulant is soft and has two forms solid rubber and silicone gel, which can eliminate most mechanical stress and play a role in shock absorption and protection. Stable physical and chemical properties, good high and low temperature resistance, long-term work in the range of -50 ~ 200 ℃. Excellent weather resistance, can still play a good protective role outdoors for more than 20 years, and is not easy to yellow. It has excellent electrical performance and insulating ability. After potting, it can effectively improve the insulation between internal components and lines, and improve the stability of electronic components. With excellent rework capability, the sealed components can be taken out for repair and replacement quickly and easily.
Silicone encapsulant is divided into two-component condensation type and two-component addition type, and the condensation type is rich in color, including black, white, and transparent. It can be used in LEDs, electronic components, and circuit boards; the addition type has better flame retardant performance and high-temperature resistance and can be used in automotive electronics and transformers.
The silicone potting compound can heal automatically after being cracked by external force, and the waterproof performance and moisture-proof performance will not be affected, which is unmatched by other types of potting compounds.The long-term and effective protection of sensitive circuits and electronic components by silicone potting compounds undoubtedly plays an increasingly important role in today's sophisticated and demanding electronic applications. Two-component silicone potting materials are undoubtedly one of the best choices. Silicone potting material has stable dielectric insulation, which is an effective guarantee to prevent environmental pollution, and can eliminate the stress caused by shock and vibration in a large temperature and humidity range.
Advantages: Polyurethane encapsulant has excellent low temperature resistance, the material is slightly soft, and has good adhesion to general encapsulation materials, and the adhesion is between epoxy resin and silicone. It has good waterproof, moisture-proof and insulating properties.
Disadvantages: poor high temperature resistance and easy foaming, vacuum defoaming must be used; after curing, the surface of the colloid is not smooth and has poor toughness, and the anti-aging ability, shock resistance and ultraviolet rays are weak, and the colloid is easy to change color.
Scope of application: Generally used for
potting of electronic components with low heat generation. Transformers, choke
coils, converters, capacitors, coils, inductors, rheostats, linear motors,
stationary rotors, circuit boards, LEDs, pumps, etc.
Advantages: Epoxy potting glue has good fluidity and can easily penetrate into the gap of the product; it can be cured at room temperature or medium temperature, and the curing speed is moderate; after curing, there are no bubbles, the surface is smooth, shiny, and high hardness. The biggest advantage is that it has good adhesion to the material, good insulation, good acid and alkali resistance of the cured product, good moisture-proof, waterproof, oil-proof and dust-proof performance, and is resistant to humidity and heat and atmospheric aging. Epoxy resin generally has a temperature resistance of 100 ℃. The material can be used as a transparent material with good light transmittance. The price is relatively cheap.
Disadvantages: weak resistance to cold and heat changes, cracks are prone to occur after being impacted by cold and heat, resulting in water vapor infiltrating into electronic components from cracks, poor moisture resistance; colloid hardness after curing is high and brittle, high mechanical stress It is easy to damage electronic components; epoxy resin cannot be opened due to its high hardness after potting and curing, so the product is a "lifetime" product, and components cannot be replaced; transparent epoxy resin materials generally have poor weather resistance, It is prone to yellowing under light or high temperature conditions.
Scope of application: Generally used for
potting of non-precision electronic devices such as LEDs, transformers,
regulators, industrial electronics, relays, controllers, power modules, etc.
