Does Your PCB Board Need Three-Anti Paint Coating? Solved

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Wed, Mar 17, 2021

three-anti paint coating

The three anti-paint is formulated to protect the  printed circuit board (PCB) and important equipment from damage. The specialized spray improves and extends PCB assembly's life of service, safety, and reliability.

In many cases, PCBs are operating in harsh environments such as high salt, humidity, vibration, and dust. Covered with the three-anti paint, the areas of the circuit board that need protection can be effectively isolated.

So it is necessary to apply the three-anti paint to your PCB assembly.


What is the Three-Anti Paint for PCB Assembly

The anti-paint is a flammable chemical that is usually saved in construction sites or warehouses, away from hot environments and smoke to prevent any fire. When operating, operators should wear masks and gloves for safety reasons. Also, the environment where the anti-paint is being kept should meet certain requirements such as not too much humidity and the nearby presence of other chemical solvents should be avoided.

Each printed circuit board design could have different electrical components, which means different anti-paint techniques. Here is how PCBONLINE applies three-anti paint for PCB coating.

Benefits of Anti-Paint Coating

The main benefits of applying an anti-paint protective coat to the printed circuit boards are mainly to  extend their life and ensure that the surface is properly protected from external influences. Also the appearance of the improved PCB, regardless of the color of the protective coat, looks better and ensures proper execution of functionalities  under higher temperature.

Another great benefit of the three anti-paint coatings is that it  avoids oxidation which can cause a variety of issues. The anti-paint also reduces the occurrence of PCB fault in SMT patch processing and prevents other problems such as insulation between the tin feet of the PCB, short circuit, and anti-static.

Lastly, the three anti-paint coatings can easily prevent dampness, insulation, and  static electricity which ensures the normal functionality for longer service life.

Here comes a question.

Do all components need three-anti paint spraying?

Some of the components on the surface of the printed circuit board cannot be covered with three-any paints. For electrical components such as plug-in devices, buttons, connectors, light-emitting diodes, and golden fingers, when using a brush coating, dip, or manual spraying, it is necessary to add masking tape. Even with fully automated selective method equipment, if the coated area is too close to the non-stackable position (usually less than 5 mm), an isolation process is required.


Four Techniques of Applying Three-Anti Paint

Here are four techniques of applying the three-anti paint to the circuit board assemblies.

  • Hand spray or brushing method: the process is low-volume, low-cost, and the operation is simple. The general issue is meeting the thickness and consistency.
    hand spray
  • Spraying with a spray gun: it is good for large-volume assemblies. The issue is requiring the high precision of the operation.
    gun spray
  • Automatic coating machine method: It can achieve precise spraying. The spraying head can avoid the three-anti pain to touch components. And the thickness uniform can be easily ensured.
    automatic coating
  • Selective automatic coating machine method: It is precise and good for large-volume assemblies. It has functions from the irregular continuous curve and three-axis linkages such as live/point/arc/face or circle.
    selective auto coating

How to Apply Three-Anti Paint to PCB Assembly

The surface of the printed circuit board should be firmly cleaned before the coating process. For products such as aerospace, automotive, military, or marine, where there are strict requirements, the coating can be applied after the PCB is washed and dried. On the other hand for the low requirements, dry high-pressure gas is used to remove any unnecessary matter from the surface of the board or any dust.

Before using the selective automatic coating equipment or machine for mass production, you should pay close attention to the first piece of inspection work. Ensure that there are no reported problems such as less coating, leaking coating, multiple coatings, or air bubbles. The area or device where the coating is denied from being coating cannot adhere and the coating uniform thickness and baking can be performed.

Lastly, the working environment humidity should be strictly controlled and it should be below 65% RH when the three anti-paint coatings are performed. The printed circuit board can absorb moisture as a composite material.

Note
After the assembly of the circuit, the circuit board should be carried out for spraying the three-anti paint as soon as possible. If the printed circuit board is left for a long time it is better to bake again before applying the three anti-paint sprays. The baking temperature is about 60 degrees Celsius for 24 hours straight.

Choose PCBONLINE for PCB Assembly

PCBONLINE provides a high-quality circuit board assembly one-stop service, which is custom. You can require applying the three-anti paint to your assembly. We ensure the beautiful outside, thickness, and consistency meeting your expectations. PCBONLINE is specialized in advanced circuit boards. Either if your circuits are simple or complex, PCBONLINE can handle the project easily and deliver it to you fast. Want your assemblies to last long and work stably? Click the button below and enjoy the best quality assembly service with the free sample and functional testing.