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Consider the following two questions:

1. Is your company a supplier of electronics or PCBs to the automotive industry?
2. Are you or your team responsible for assuring a steady supply of quality products such as conformal coatings and encapsulants? 

If so, we would respectfully ask you to consider adding IATF 16949 certification to your list of requirements for your key suppliers. 

Many coatings suppliers continue to focus on minimizing costs and maximizing profits. As a result, most have not taken the time or expense to get themselves IATF certified. In our conversations with major OEMs, we can assure you that the IATF certification of your suppliers can be of great value and help you sleep better at night.

Related Article: Understanding IPC-CC-830B Qualification Standards 

For decades, Chase Corporation and our Humiseal brand have been the originators and recognized leaders in PCB protection with conformal coatings. Humiseal also provides products and technical support for a complete line of encapsulants. While conformal coatings provide adequate protection in most instances, sometimes you just need a little more coverage! Humiseal encapsulants add a whole new level of protection against extreme temperature and chemical exposure.

So, if you currently use Humiseal conformal coatings, there are certain industry-established methods, both manual and automated, for applying them. This usually involves either spraying them, manually hand brushing conformal coatings, or dipping the entire board. Encapsulants are quite different and the following are some common application methods with pros and cons to help in your decisions.

Conformal coating is generally the last step in the PCB manufacturing process and the method of protection for all those valuable functional components, but it's not always that simple. Let's look at a fairly common scenario.

Everything was moving along fine through the design and testing process. You have begun production spraying and suddenly there are wisps of translucent webs floating in the air. Your taller components look like a scene from the movie Arachnophobia. This is the oft-dreaded cobwebbing effect; and while it may appear confounding and a little scary, it is often one of the simplest problems to eliminate when conformal coating.

In this brief article, we will discuss the likely causes of this odd situation and provide some simple solutions to get you back to applying your coating in a defect-free manner.   Let's begin by exploring the phenomena in more detail.

Bubbles. They can be a real challenge in any adhesive or coating, but they are particularly undesirable when covering electronics and printed circuit boards (PCBs) with fluid conformal coating material. The technical support engineers at Humiseal have over five decades of experience in support of PCB manufacturers. They report that bubbles within the finished film are the most commonly reported technical issue they receive.

In this brief article, we will discuss many of the causes as well as many potential solutions to the problem of entrapped bubbles.

Toluene and Xylene: solvents that have shown value and utility within the adhesives and coatings industries for decades. However, they often serve as a double-edged sword, offering superior solvent and drying capabilities but accompanied by some negative health and environmental impacts.

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.

Conformal coating technology is on a continuous path of improvement, and we're excited to say the latest step on that path just happened. UV550 is the most recent innovation from HumiSeal, continuing the trend of industry-defining capabilities in the conformal coating space. This is to be expected from the original inventors of conformal coating material. But what sets UV550 apart from the rest?

Let's discuss how the ever-changing requirements of the automotive and white market space fueled the thresholds this uv-curable material attains, especially with regard to its durability under the most extreme thermal and mechanical cycling conditions.  

HumiSeal development specialists have been designing high-performance, UV-curable conformal coatings for approximately three decades. Compared to legacy solvent-borne and silicone technologies, UV- curable coatings provide some unique properties that can be of great value such as- 

• Nearly instantaneous, consistent curing 
• Superb moisture and environmental protection
• Little or no VOC content

These coatings also lend themselves well to high-speed and high-volume applications due to manufacturing advantages such as- 

• Minimal WIP due to immediate cure capability 
• Low material cost due to 100% solids chemistry
• Smaller manufacturing footprint due to much smaller curing equipment

We at HumiSeal are no strangers to conformal coatings; and if you’re reading our blogs, it’s likely you’re familiar with these coatings as well. The word “conformal” is descriptive of the function of the coatings which are expected to spread and conform evenly across all surfaces that are to be protected. This uniform and even distribution is necessary to protect delicate electronic components from things such as humidity, water, vibrations, and thermal damage (to name a few).

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.