FEATURED VIDEO
Robotic conformal coating of PCB assemblies
Video Transcript
Conformal coating of printed circuit board assemblies helps ensure their reliability, especially when they’ll be used in products for outdoor or industrial settings.
A thin layer of special urethane or acrylic is applied to the PCB assembly, conforming to its topography and protecting it from moisture condensation and other contamination.
At Z-AXIS we use a programmable robotic system for conformal coating. Nozzles move along a pre-programmed path, dispensing a precise amount of coating, exactly where we want it.
We use an atomizing spray nozzle to coat large areas of the board at high speed, and a micro dot dispensing nozzle for details like edging around tall components and around areas that we want left uncoated, such as contact pads. Each nozzle is a substantial investment, but adds to quality and throughput.
The precision of this system lets us eliminate the manual step of masking the areas we don’t want coated, for a significant reduction in labor costs as well as higher throughput, higher consistency, and better quality.
A manufacturing engineer programs the system, defining the optimal pattern for each board, including which nozzles to use, the path for each, and amount of coating to dispense. The process is validated and repeatable.
At Z-AXIS we primarily use solvent-less urethane rather than acrylic for conformal coating. Urethane is more expensive than acrylic but has several advantages:
- One, It is cured by controlled exposure to intense UV light and does not shrink while curing; so you don’t get the thin spots and gaps that you can get with acrylic.
- Two, It cures more quickly and can ship immediately after inspection, vs. acrylics’ hours-long dry time.
- Three, we don’t have to deal with solvent fumes, so it’s better for employees and the environment.
The robotic system helps us keep urethane material cost down. With its uniform application there no unnecessarily thick areas of coating,
and we don’t waste coating on masks or fixtures that have to be discarded or cleaned off.
Whether you use urethane or acrylic, the benefits of robotic conformal coating include:
- More consistent coverage for higher yields and better protection of PCB assemblies.
- Higher throughput for lower production costs and faster delivery.
- Reduced environmental impact through reduced waste.
Robotic conformal coating is just one of the advanced processes we use at Z-AXIS to produce high quality, high reliability boards for our contract manufacturing customers.