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PCB Encapsulation - The Best Way to Protect Electronic Circuits PCBs are used in numerous industrial, domestic, automotive and military devices, often in extreme environments. Exposure to moisture, harsh chemicals and other harsh conditions can damage PCBs, resulting in a reduction in electrical performance of PCBs or complete failure of the device. PCB encapsulation with resins ensures that the circuits are well protected. These resins offer the highest level of protection. Encapsulation of the entire PCB with resin allows for complete insulation, thereby giving the unit excellent electrical properties and mechanical protection. The extent of encapsulation varies according to the application and plastic activation.

Mechanical protection includes superior protection for applications that are exposed to vibrations PCB Prototype, and thermal or physical shock. PCB encapsulation involves the use of a dispensing machine with resins commonly two parts which when mixed together under controlled temperature and pressure form a solid, fully cured protective material. The entire unit is tested thoroughly for its intended use in an appropriate environment. This could be planned accelerated testing. The resins can also be tested independently in different environments to determine the precise specifications and suitability. The dimensions and weight of the resins are measured before and after the test to record any changes, if any. Other tests include electrical testing, which is specific to the final application Rigid flex.

PCB encapsulation is a cost effective and accurate process that ensures that PCB assemblies operate safely in various conditions. Encapsulants are available in solid and liquid form although their composition is similar. Epoxy molding compounds are solid types that are a blend of solid epoxy resin, additives, flame retardant, and hardener. On the other hand, liquid encapsulants have liquid resin and hardener so that the material can be applied directly on the chip and interconnect using the dispensing machine. Most encapsulants use epoxies that react with hardeners such as anhydrides. One of the major reasons for using epoxies is because of their versatility and balanced characteristics. The additives bring the properties to the desired level to act as encapsulants. Flame retardants are added to the process to meet the required specifications and reduce flammability.

Solid and liquid epoxies are polymerized. The compounds are low melting mixtures of resins and other material that is polymerized into a structure with good mechanical strength and thermal stability to ensure there is no damage in the soldering assembly process. In liquid encapsulants, polymerization occurs when heat is applied to the unit that contains epoxy resin, hardener, and an accelerator. One of the common processes of encapsulation is transfer molding. Connected chip are fed into a mold cavity of a molding machine. The epoxy molding compound is preheated and melted into a liquid and injected into the mold cavity to surround the chip and wire bond structure.
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