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If you're familiar with HumiSeal through our blogs, you know we are big fans of conformal coatings. This is for good reason; with advancing conformal coating technology, innovative LED and UV curable coatings offer incredible protection for a large range of applications.

Conformal coatings are just one method of circuit board protection available to engineers. Those involved with PCBs may be familiar with the terms encapsulation. Encapsulation is a tremendously powerful method to secure and protect PCBs by submerging them in a protective material. In many cases, this is more desirable than selectively applying conformal coatings.

Conformal coatings have a long and storied history with printed circuit boards. A good conformal coating protects PCB components from moisture, corrosion, contaminants, and additional PCB threats like vibration and thermal shock. Coatings are a complicated science, and there isn’t one best coating or application method for every job. These choices are dependent on the design, use case, and assembly of the PCB. For instance, manual brushing PCB coating material is a slow, tedious process; but for small batch applications, it’s quite cost-effective.

Regardless of the chosen method, there are fundamental application errors that can occur, leading to defects forming in the coating which ultimately limit the functional service life of the PCB.

In the days before surface mount printed circuit assemblies, components (such as resistors, diodes, and capacitors) were axial, and printed circuit board components were installed with the “through-hole” method using large conductor spacing. With the advent of integrated circuits, these too were through-hole with good spacing between legs.

We at HumiSeal would like to dedicate a bit of time and space to one of the most often ignored factors related to successful conformal coating processes: Clean Air.

The transition to LED curable conformal coatings is beginning to build momentum, beginning as a slow evolution and developing into a revolution of sorts. The driving forces behind this include: 

• Improved processing equipment designs and availability 
• Aging or outdated application equipment replacements 
• Increasing range of LED curables commercially available or in development 
• Rising labor, equipment, and energy costs  

If you and your organization are faced with aging equipment and higher costs, there isn't a better time to consider the potential advantages of LED curable conformal coatings! 

 HumiSeal UV20Gel is a unique, strong, and flexible gel coating developed to protect PCB (Printed Circuit Boards) components against environmental conditions and vibrations. UV20Gel has proven successful in many demanding industries and product families including-

One of the most basic and common questions we at HumiSeal^® are asked by both existing and potential new customers is,

“How much does it cost to conformally coat my printed circuit boards?”

Since conformal coatings are usually sold in liquid form by the liter or gallon, it is necessary to go through a fairly basic calculation that we will present here.

The simplest and most common way to evaluate cost is by determining the cost in dollars of coating per PCB.

The PCB industry continues to evolve with ever increasing demands for efficiency and manufacturing cost reductions. From the design phase onward, suppliers and contract manufacturers are being asked by their OEM overlords for increased performance at lower and lower costs. An obvious potential source for cost reduction is the use of alternative cheaper raw materials or their elimination where possible. At some point in the discussion, it is sometimes asked,  “Why don’t we just eliminate the conformal coating?” or "Are conformal coatings necessary".

Conformal coating of printed circuit boards (PCBs) has resulted in a steady evolution in performance and protection for modern electronics. It has allowed for lightweight and reliable controls in industries such as automotive and aerospace among others. This has brought about the possibility of increased length of warranties as well as fewer failures and claims. Nevertheless, original equipment manufacturers (OEMs) and consumers continue to raise their standards and expectations for longevity and reliability to levels unimagined just 10 years ago. In the automotive industry, as an example, thermal cycling testing might have involved as few as 10 or 50 cycles in the recent past. That standard is now often 500 or even 1000 cycles with no apparent ending in sight.

So what do I do when conformal coating is not enough?