Materials and processes for PCB potting

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There is a PCB board in all electronic devices, and the service life of these products basically depends on the service life of the PCB. Therefore, protecting the PCB well has become an important item. Here, LST introduces a technology that can protect PCB well, it is PCB potting.

What is potting PCB?

Potting is a way of protecting PCBs from heat, environmental hazards, and chemicals. This is mainly due to the fact that the outer shell of the PCB is filled with a substance that is used to protect the entire PCB and components.

1.Potting enhances electronic performance and circuit dependability by protecting PCBs from tampering, moisture, and voltage leaks. Potting also shields electronics from the effects of vibration and stress, preventing wiring disconnections and early system failure.

2.Additionally, the PCB and PCB case’s vibration waves may pair, intensifying stress on the PCB and causing early failure. PCBs become stress and vibration resistant through potting.

3.Also, Encapsulation protects PCBs from dirt and dust, which can cause overheating, signal interference, and decreased speed or performance.

4.Lastly, PCB board potting improves the security and privacy of the electronic device. The nature of potting makes accessing your PCB and reverse engineering your device incredibly challenging, thereby enhancing the privacy and security of your PCB board.

5 types Potting Compounds

One option is epoxy, which is a durable material with great chemical resistance and high adhesion strength. However, epoxies require a long time to fully cure and set.

Polyurethane is another choice – it is softer and more pliable than epoxy. This makes polyurethane useful for protecting fragile electronic components that may not work well with rigid potting compounds. However, polyurethane tends to have lower heat and moisture resistance compared to some alternatives.

Silicone can also be used for potting PCBs. It is extremely flexible and can withstand extreme temperatures. The downside is that silicone tends to be more expensive than other potting materials, so it may not be practical depending on the application.

Acrylic adhesives are readily soluble in many organic solvents, making it easy to complete repairs to panels and often providing only selective chemical resistance. Acrylic adhesives offer the advantages of quick drying, good mold and mildew resistance, no shrinkage during curing and good moisture resistance. The disadvantages, however, are low abrasion resistance and susceptibility to scratching, chipping and peeling.

The last species is urethane, which is very protective, hard and highly resistant to solvents, providing excellent abrasion resistance and low moisture permeability. It also has good low-temperature adaptability, but does not work well in high-temperature environments and most cannot be repaired or reworked.

Various materials have different pros and cons that should be considered, choosing the right material is determined by applications. For example, silicone and epoxy are perfect for the circumstances under high temperatures; however, urethane would have the better protection performance to chemicals. So the key point that we should notice when selecting the material is that we need to have a clear thought about what kind of protection we want to achieve.

How to choose PCB potting materials

The following factors need to be considered when choosing a coating material for circuit boards:

1. Heat resistance: circuit boards usually operate at high temperatures, so the coating material must be able to withstand high-temperature environments.

2. Insulation: The coating material should have good insulation to prevent the circuit board from short-circuiting or other electrical failures.

3. Chemical resistance: Since the circuit board may come into contact with various chemicals during use, the coating material needs to be chemically resistant.

4. Solderability: The coating material should be solderable to facilitate the soldering and repair of the circuit board.

5. Wear resistance: the circuit board may be subject to wear and tear during use, so the coating material needs to have a certain degree of wear resistance.

6. Cost: The cost of the coating material is also one of the factors to be considered when selecting the material.

Process flow of PCB potting board

Prepare
▶The potting compounds
▶A container or a bucket
▶A stirrer
▶Precision scales
▶Whenever the resin is ready, you will need the following materials for the PCB ▶board potting process:
▶Protective mask
▶Protective neoprene gloves
▶Protective clothing
▶Protective glasses
▶To ensure high-quality results, you need to control the resin. This step requires:
▶A hot air oven
▶Hardness tester (analog shore a)


Circuit board potting can improve its stability, reliability, extend its service life, but also to protect it from the impact of the environment. In the specific operation of the time we have to choose according to the performance requirements of the product with what materials and methods, about PCB potting more knowledge, you can consult our online customer service.