Manual brushing is just one of many methods commonly used for applying conformal coating materials to PCBs and other components. It is a hand-applied method that requires little investment into automation or equipment. With practice, it can be one of the simplest methods available, especially for small-batch production or isolated applications.
This blog is the second installment in our two-part series on viscosity (with special consideration on adhesives and coatings).
In our previous viscosity blog, we discussed the properties of viscosity and how viscosity can be affected by temperature, the addition of dilution or thinning agents, and other similar factors.
Chase Corporation, through our HumiSeal® and Resin Designs divisions, has spent the past decade preparing protection and reliability solutions for complex electronics. Notably, within the emerging EV market, we have identified needs within the assembly of EV motors where superior adhesion and protection are particularly critical.
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-
Durable Protection for Demanding Automotive Requirements
HumiSeal chemists have been designing state-of-the-art conformal coatings for nearly 70 years, first producing UV curable coatings more than two decades ago. At that time, UV curable technology was considered the next generation of coatings, mainly due to its advantages; including:
Counterfeits exist. Our industry is no exception. We’ve pointed out counterfeit conformal coatings on two separate occasions, but it is time to do so again. Unlike most electronics components, damage attributed to counterfeit conformal coatings is often unreported as it can be challenging to tell the difference between counterfeit brands and the original coating. The best way to protect yourself against this is to purchase directly from HumiSeal or one of our authorized channel providers.
This is the first in a short series on material viscosity, in which we will review what it is and how to measure it. We will start with the definition of viscosity. Viscosity is the internal friction of moving fluid and a measurement of the resistance of a fluid deformed by shear stress. It is measured in centiPoise. The lower the number, the less viscous the material, as can be seen by this comparison chart: starting with water at 1 cPs and ending with honey at anywhere between 2,000 – 10,000 cPs.
Conformal coating with parylene is a very different process compared to coating with traditional solvent-borne or UV curable materials. Parylene coating has some advantages including
- a very thin application profile,
- uniform and complete surface coverage, and
- generally excellent protection and minimal outgassing potential.
On the other hand, parylene coating also presents unique challenges such as
- a significant investment in complex equipment,
- batch processes that limit productivity and increases costs, and
- the user’s inability to selectively control where the coating is applied.
It is this final challenge that we will concern ourselves with within the following discussion.
Most anyone over the age of 30 has probably seen Back to the Future and remembers Marty McFly. One line of Marty’s that inexorably drew him into ill-advised actions was the classic “Nobody calls me yellow.” Nothing good comes from yellow, and this turns out to be just as applicable in LCD screen manufacture as it was in the movie.
During the assembly process, the use of a liquid optically clear adhesive (LOCA) is important for ideal visual properties in LCD screen manufacture. The assembly process has evolved and advanced, but there are still potential weaknesses or defects that must be taken into account in both adhesive selection and process design. In this blog installment, we will discuss one of these potential defects: entrapped bubbles.