Insights from BCC Research

Taking a Peek at Conformal Coatings

Posted by Clayton Luz on Dec 29, 2016 10:00:00 AM

You're standing at a street corner in a downpour with your umbrella and cell phone out. You're tapping commands on an app that will get you the nearest cab. A transit bus, roaring past in the rain-soaked street, sends a curtain of water over the sidewalk. You sidestep the mini-tsunami, but your phone gets drenched.

 
Replacing a phone can be expensive, not to mention a hassle. Your panic about the imagined death of your phone is short lived, thankfully. Although dripping wet, it still works fine. Whew.
 
You can thank the material that coats your phone for protecting it. Because device failure could have serious consequences, electronic manufacturers use a process called conformal coatings. These transparent materials protect electronic assemblies like circuit boards or electronic devices against rain, heat, cold, snow, vibration, fungus, oxidation, corrosion, in sum, any "environmental attack," including "street-corner" showers.
 
Conformal coatings find use in the auto, aircraft, military, medical device, wearable electronics industries. Among other uses, coatings also prevent electrostatic discharge, electromagnetic interference, and radio frequency interference.
 
One company is ramping up its approach to ensuring that our devices are defensed against "environmental attacks" by inspecting the integrity of their conformal coatings.
 
In conformal coating inspection (CCI), special LEDs illuminate coatings that are mixed with particles that fluoresce under UV light. The coating layer typically fluoresces in blue under this excitation. With the right frequency adjustments, common defects like bubbles, contamination, or missing coatings are detected.
 
Viscom AG, which specializes in  assembly inspection for electronics manufacturing, developed a module for CCI in electronics production. The company claims that the product, the HighDensity module, works as an option to its S3088 CCI system. It's recommended when nano-plasma (think really thin coatings) coatings need inspection, Viscom says.
 
It can also be used to inspect extremely temperature resistant silicone-based coatings that are used, for example, to make smartphones (like the one at the bus stop) resistant to moisture.
Among its other features, the module features special high-power LEDs which are attached about the camera. Their UV light (black light) with special wavelengths provides optimum illumination, even for coatings with weak fluorescence properties.
 
The system works with efficient ultraviolet illumination, which contrasts the UV-reactive protective conformal coating against the background material. According to the Germany-based company, the spectrally sensitive cameras visibly identifies even the smallest of flaws.
 
The system can also be fitted with four to eight cameras, angled in a configuration that affords inspection of hard-to-see spaces on the components, the company claims.
 
Makes one wonder if umbrellas should come equipped with angled cameras, for a heads-up against getting drenched by busses plowing through puddles.

Topics: Information Technology