PCBA Tech - Precautions for the use of three anti-paints for PCBA circuit boards

Precautions for the use of three anti-paints for PCBA circuit boards
At present, the country has higher and higher requirements for environmental protection and greater efforts in link governance. This is a challenge but also an opportunity for PCB factories. If PCB factories are determined to solve the problem of environmental pollution, then FPC flexible circuit board products can be at the forefront of the market, and PCB factories can get opportunities for further development.
The three-proof paint for PCBA circuit boards is mainly used to protect PCBA boards from environmental erosion. PCBA circuit boards that have used three-proof paint have the "three-proof" performance of water-proof, moisture-proof, and salt-fog resistance, as well as resistance to cold and heat shocks, aging resistance, and Radiation, salt spray resistance, ozone corrosion resistance, vibration resistance, strong adhesion and other properties.

When coating the PCBA circuit board with three anti-paints, some parts of the PCB board cannot be coated, and many things need to be paid attention to.

1. Matters needing attention when applying three anti-paint

   
   

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1. The surface of the PCB must not have paint flow, dripping, or semi-wetting.

2. The three-proof paint layer should be flat, bright, uniform in thickness, and protect the surface of pads, pasted components or conductors.

3. The surface of the paint layer must not have orange peel, bubbles, pinholes, or ripples.

4. There is no need to brush the three-proof paint on the devices or components that do not need protection.

5. The printed board after the three proofings should be clean, tidy and free of component damage.

6. There are no dirt, fingerprints, ripples, shrinkage holes, dust and other defects and foreign objects on the board and components, no chalking, no peeling phenomenon.

2. List of components that cannot be coated with three anti-paint

1. High-power with heat dissipation surface or radiator components, power resistors, power diodes, cement resistors.

2. Dip switch, adjustable resistance, buzzer, battery holder, insurance holder (tube), IC holder, touch switch.

3. All types of sockets, pin headers, wiring terminals and DB headers.

4. Plug-in or paste-type light-emitting diodes and digital tubes.

5. Other parts and devices that are not allowed to use insulating varnish specified in the drawings.

6. The screw holes of the PCBA board cannot be painted with conformal paint.

Moisture has always been the most common and destructive main factor for PCBA boards, and the three-proof paint can protect PCBA boards from moisture. iPCB has passed ISO9001:2008, ISO14001, UL, CQC and other quality management system certifications, and produces standardized and qualified PCB products. We master complex process skills and use professional equipment such as AOI and Flying Probe to control production, X-ray inspection machines, etc. . Finally, we will use double FQC inspection of appearance to ensure shipment under IPC II standard or IPC III standard.