Conformal Coating & Potting:
Protect Your Components From Harsh Conditions
It’s not a surprise that there will be cases where electronic components will have to operate in harsh environmental conditions. This means it is important to take preventative measures to ensure the components will function even in harsh conditions – like water, dust, rust, humidity, temperature, and more. The number of electronic and photonic components in today’s technology is much higher compared to those in the past. This means if one of the many components were to malfunction; it can directly impact how other components will function.
So how exactly can you protect your component against these harsh conditions?
If we take a look at today’s electronic devices you will notice that many of them still work even against conditions to which they are commonly susceptible – e.g., water-resistant phones. This is because much of today’s technology comes equipped with the appropriate design, components, and materials to protect them against conditions that they’ll like to face during usage.
Implications of Harsh Environments
One of the conditions to which most electronics are susceptible is moisture. Moisture is the primary cause of corrosion – which is detrimental to electrical components. Metal corrodes much quicker when exposed to humid conditions. The reason for this is that the moist-saturated air causes a reaction with oxygen and electrons on the surface of the metal. The longer the exposure of metal components to humid air, the quicker the rate it will corrode.
Another factor that exposes electronics to malfunctioning is temperature. Abrupt temperature changes can have a significant impact on the stability of the performance of electronic devices. This is especially true when components are exposed to high temperatures for long periods. This means if devices are not provided with the appropriate protections, it can compromise the device’s overall performance in the long run.
To solve this problem, two methods are commonly used today to protect electronic devices from the aforementioned problems:
- Conforming coating
Let’s dive into the details of how these methods can help protect your electronic devices.
What Is Conformal Coating?
Conformal coating is a technique that involves the use of a protective coating to enhance the durability of the delicate components on the PCBs (printed circuit boards). This protective coating is applied to help protect the electronic circuitry against factors such as moisture, dust, chemical substances, and sudden temperature changes. This prevents the board from corroding. Additionally, conformal coating is used to reduce the formation of ‘whiskers’, as well as preventing current bleeding between closely positioned components.
A variety of materials can be used as conformal coating, this includes Acrylics, Urethanes, Silicones, and Varnish. Each serves a unique purpose and provides advantages in certain environments and manufacturing scenarios.
There are several ways to apply conformal coating – the most common methods being: brushing, spraying, dispensing, and dip coating. Each of these methods has its pros and cons, and choosing the wrong application method can hinder the efficacy of the coating and performance of the PCB.
Let’s take a closer look at each method and see which one best fits your needs.
Application with a brush
As the name suggests, this method is used to apply coating onto the PCB with a brush. This method is ideal when used in low-volume applications, where it is easier to select the areas to be coated. The disadvantage of this method is the finish tends to be lacking and can result in defects such as bubbles. Additionally, it’s also difficult to apply an even coating with this method, unless a skilled operator is applying it.
This method involves the use of machinery to fully immerse the entire PCB in the coating. This allows the coating to penetrate the entire PCB including gaps and spaces beneath devices which tends to be difficult to access. If the PCBs are designed correctly, this form of application is perfect for high-volume production. However, to be suitable for dip application the PCB must be designed appropriately, with materials that have a low viscosity to penetrate the casting holes freely.
Conformal coating machine application
This method refers to using a machine to coat certain areas on the PCB. This method is the preferred choice among manufacturers for high-volume applications of the same parts. The advantage of this method is its ability to quickly and accurately apply the coating to areas where it is required. This guarantees an even and reproducible coating of the desired thickness. The caveat to this method is that it requires someone skilled to operate the machine, and penetrating components may require extra attention.
Spray application is a cost-effective method of applying conformal coating, as it can be completed simply by hand (or automated) with a spray aerosol. This method is ideal for small-medium scale production. The main advantage of this method is that it gives excellent tip coverage to components.
The disadvantage of this method lies in the possibility of overlapping layers, which results in a thicker coating than intended. Additionally, spraying with a machine makes it difficult to reach the underside of components which leads to an uneven coating.
What is Potting?
Potting is another method used to protect electronics from the surrounding environment. Instead of coating the PCB with a protective film, Potting uses a protective shell to incapsulate the PCB on the device. This solution helps protect the PCB against factors like shock/vibration, water, moisture, mechanical damage, or corrosion.
The Potting process involves placing the electronic component inside a container(pot) which is then filled with a liquid compound – covering it completely. The liquid compound will then harden, securing the device inside. Once this process is finished, the mold itself may become part of the finished product to provide it with additional shielding or heat-dissipating functions.
Potting is the ideal choice if the goal is to protect electrical components from substantial impact or rough mechanical abrasion. Other advantages include vibration dampening, heat dissipation, and privacy and security.
The main disadvantage of Potting is the increase in size and weight of the component compared to conformal coating. This means that Potting may not be suitable if there are certain thickness and weight requirements.
Both Potting and Conformal Coating are excellent ways of protecting your electrical components against external factors; however, choosing between the two will depend on the specific needs of your business. Many variables must be considered when deciding between the two, as it will determine the cost, efficacy, and turnaround time of your project.
Before making a final decision, consult with a professional to help choose the best protection for your project.
If you are looking for a company that can help you choose the best protection for your project, we have the solution for you! At ECI Technology, we have professionals with extensive experience in conformal coating and potting arena to provide high-quality and reliable products to meet the need of your business.