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How To Protect Your PCB From Moisture | Tablets

Mallory McGuinness | May 07, 2020

Next year will be a big one for tablets. By 2021, there will be 1.28 billion tablet users around the world. Specifically, 18.9% of the global population will be sharing, swiping, and scrolling on these devices, the highest user penetration rate for tablets in history.

Versatility might be the main driver behind this growth. These devices provide consumers with the convenience of cell phones with features like GPS navigation and the productivity of a computer, with a flat design that allows work on any surface.

Use cases do not end just there. Diversified industries, including manufacturing, medical, construction, and transportation verticals, have begun to employ the use of these devices, encouraging the evolution of different types of tablets that segment the market.

For example, in the consumer electronics industry, the hybrid tablet, a laptop combined with a tablet that has a removable screen, is becoming popular. Meanwhile, rugged tablets come with a shock-mounted internal hard drive and protective shield to handle extremely harsh environments, making them ideal industrial devices.

Along with fantastic versatility, emerging technology trends such as waterproof tablets will significantly boost market growth. This tendency is both good and bad news for device designers. While versatility and waterproof features that prevent damage are motivating purchases, achieving this kind of adaptability can be a challenge.

How to Protect Electronic Components from Moisture – Harder than it Seems

Building a waterproof tablet of any type that can be used virtually anywhere is a struggle. When any liquid – from coffee or wine to rain, salt spray or sweat – makes contact with a device PCB, a short circuit or corrosion can serve as a death blow. Even humid environments and corrosive gases can infiltrate devices over any period of time, causing damage.

The common threats found in environments do not bode well for tablets. These products have many gaps that serve as a point of entry for liquids. Any port, speaker grille, or microphone hole could be the weakest link that allows liquid to leak in. To operate reliably, it is essential to prevent moisture and high humidity damage.

PCB Moisture Protection for Tablets

Applied correctly, conformal coatings can be a strong line of defense for your product’s weakest links. These thin polymeric films can be applied to a circuit board, protecting the printed circuit boards and their electronic components inside of a tablet from liquid damage and corrosion deterioration.

Conformal coatings reduce the need for complex, bulky encapsulation and seals, providing sturdier protection against chemical and corrosive attack. The thinness of these films has only a minimal effect on component weight and the coatings can improve the performance and reliability of tablets that are subject to environmental conditions.

However, the problem with traditional conformal coating materials is that they are not intelligent; they go where they are placed, and they must be appropriately applied. The films must fully cover exposed metal surfaces within tablets to be useful as a moisture barrier. Otherwise, any voids in the coating produced during the application, such as bubbles or cracks, will serve as corrosion hot-spots.

Therefore, the process used to apply conformal coatings, and the control and workmanship within this process will have the most significant influence on the failure or success of a coated assembly in surviving its operating lifetime and circumstances.

one phone underwater that is still working because of HZO protection and another that is dead because of water damage

When any liquid – from coffee or wine to rain, salt spray or sweat – makes contact with a device PCB, a short circuit or corrosion can serve as a death blow.

IPX7 PCB Waterproofing for your Consumer Electronics Product

Parylene is a conformal coating with a specialized chemical vapor deposition (CVD) process. Using CVD, powdered Parylene dimer is transformed into vapor, depositing a uniform, pinhole-free protective covering that penetrates device crevices.

With Parylene deposition, a high level of protection is also achieved at around 10% of the mass of spray or dip coatings, which is a useful feature for miniaturized components commonly found in tablets.

Parylene’s CVD-generated protection effectively repels water and other sources of moisture with exceptional barrier control under an extensive range of environmental conditions, making it virtually waterproof for most performance circumstances.

Conformal and Hydrophobic Coatings for Electronics

Despite the many benefits CVD offers, it is still a batch process that requires a sophisticated vacuum machine. Although some companies provide this type of equipment, they provide it alone. It can be challenging to find a vendor who can supply advanced coating materials, experts with deep domain expertise, and an understanding of material science as well as top-of-the-line equipment to meet conformal coating needs. HZO is a one-stop-shop for thin-film and nano coatings, offering all of these assets with our turnkey solution.

Contact us today if you would like to tap into the power of convenient, reliable electronic protection.

The problem with traditional conformal coating materials is that they are not intelligent; they go where they are placed, and they must be appropriately applied.

Mallory McGuinness

Mallory is an electronics protection evangelist who writes content for HZO. In her free time she is reading non-fiction, and hanging out with her beta fish, King Awesome.

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