I. Introduction
With the continuous trend of miniaturization and high performance of electronic devices, controllers and power controllers, as key components, their stability and reliability are of vital importance. Silicone encapsulant, with its unique properties, plays an indispensable role in these two types of devices.

II. Performance Characteristics of Silicone Encapsulant

1.Excellent Electrical Insulation Performance: Silicone encapsulant has a high resistivity, which can effectively prevent current leakage. In the complex circuit structures of controllers and power controllers, it ensures the electrical isolation between various electronic components, reduces the risk of short circuits, and ensures the stable operation of the equipment. For example, in high-frequency switching power supply controllers, it can effectively suppress electromagnetic interference and maintain the accuracy of circuit signals.
2.Outstanding High and Low Temperature Resistance Performance: It can maintain stable performance within the temperature range of -50°C to 200°C. For power controllers, a large amount of heat is often generated during operation. The silicone encapsulant can withstand high temperatures, preventing softening, deformation, or performance degradation due to excessive temperature. In low-temperature environments, such as outdoor controllers, it will not become brittle or crack, ensuring the normal operation of the equipment under extreme temperature conditions.
3.Good Flexibility and Shock Resistance: After curing, it has a certain degree of flexibility and can buffer the stress on electronic components caused by vibration and impact. In the application scenarios of industrial controllers, the equipment may be affected by mechanical vibrations. The silicone encapsulant can absorb the vibration energy, protect the internal components from damage, improve the shock resistance of the equipment, and extend its service life.
4.Waterproof, Moisture-proof and Chemical Stability: It has a good barrier effect against water and moisture, which can prevent the internal circuits of controllers and power controllers from short circuits and corrosion due to moisture. It has stable chemical properties and is resistant to the erosion of various chemical substances. In environments with chemical pollutants, such as the control equipment in chemical enterprises, it can protect electronic components from being damaged by chemical substances.

III. Applications in Controllers

1.Automotive Electronic Controllers: Automotive engine control units (ECUs), body control modules (BCMs), etc., operate in a complex environment. The silicone encapsulant can protect the internal circuits from the high temperature and humidity in the engine compartment and the vibrations during vehicle driving, ensuring the stable operation of the automotive electronic control system and the safety and reliability of the vehicle.
2.Industrial Automation Controllers: In factory automation production lines, programmable logic controllers (PLCs) are used to control the operation of various equipment. The silicone encapsulant can protect PLCs from dust, oil stains, and electromagnetic interference in the workshop environment, improve their working stability in harsh industrial environments, and ensure the continuity of the production process.

IV. Applications in Power Controllers

1.Switching Power Supply Controllers: Widely used in the switching power supplies of various electronic devices, they generate a large amount of heat during operation and have high requirements for electrical performance. The silicone encapsulant can not only achieve good electrical insulation but also help with heat dissipation, transferring the heat generated during the operation of the switching power supply, improving the power conversion efficiency, and reducing the failure rate.
2.Uninterruptible Power Supply (UPS) Controllers: In places with extremely high requirements for power supply stability, such as data centers and hospitals, UPS is a key device. The controller is encapsulated with silicone encapsulant, which can ensure that the controller works stably under complex working conditions such as mains power interruption and switching, and ensure that the UPS can reliably provide continuous power to the load.

V. Application Process and Precautions

1.Application Process: Generally, it includes steps such as surface cleaning, mixing (for two-component silicone encapsulant), encapsulation, and curing. Before encapsulation, it is necessary to ensure that the surfaces of the controllers and power controllers are free of impurities such as oil stains and dust. For two-component encapsulants, they should be mixed evenly in strict accordance with the specified ratio. Appropriate encapsulation equipment (such as syringes, encapsulation machines, etc.) should be used for encapsulation to ensure uniform filling of the encapsulant and avoid the generation of bubbles. According to the characteristics of the encapsulant, appropriate curing conditions (temperature, time) should be selected.
2.Precautions: The performance of silicone encapsulants of different brands and models varies. It is necessary to select them reasonably according to the specific working environment and performance requirements of the controllers and power controllers. During the encapsulation process, attention should be paid to the temperature and humidity of the operating environment. Excessive humidity may affect the curing effect of the encapsulant. When repairing or replacing electronic components, some encapsulants may be difficult to remove, and their maintainability needs to be considered.

VI. Conclusion
Silicone encapsulant, with its excellent comprehensive performance, plays a key role in the protection and performance improvement of controllers and power controllers. With the continuous progress of electronic technology, higher requirements will be put forward for the performance and application process of silicone encapsulant, which will promote its continuous innovation and development and better meet the reliability requirements of various controllers and power controllers in complex working environments.