What is the Best Way to Protect PCBs?

Protect Your Printed Circuit Board

Automotive electronic circuits started as simple switches for headlights and windshield wipers but have evolved significantly to become integral components found in today's complex systems for ADAS, infotainment, and autonomous vehicle designs. With the increased consumer demand for more safety, comfort, and entertainment in automobiles, manufacturers face the challenge of finding reliable, economical, and high-performance circuit materials that minimize the effects of printed circuit board failure in these systems.

One way to address the issue of a field failure is to properly protect printed circuit boards from fluids that may damage and/or compromise the safety and operation of the vehicle. If left uncoated, leakage or corrosion can harm delicate components. Conformal coatings are a good solution for this problem because they are applied to form a protective layer of thin polymeric material to PCBs to help improve circuit reliability in harsh conditions including humidity, dust, fungus, extreme temperatures, and other contaminants. 

To further investigate this issue, Dymax conducted a study on six of its leading light-cure conformal coatings to test their chemical resistance against seven fluids commonly used in the automotive industry. The conformal coatings were applied to printed circuit boards and cured for 20 seconds using a Dymax 5000-EC flood lamp at an intensity of 200 mW/cm2. The test samples were then immersed in the test fluids for 72 hours, after which they were removed and wiped clean. The PCBs were left at room temperature for one week. The initial weights of the sample coatings were recorded as well as the weights after the 72-hour soak and after one week.

The table below shows the initial weights of the tested circuit boards, the weight of the PCBs after one week at room temperature, and the percentage of weight change. The results show the Dymax conformal coatings performed well because the percentage of weight change after the 72-hour soak was minimal and continued to drop during the resting week period. 

Dymax Conformal Coatings: Chemical Resistance Study Results Table


For manufacturers designing automotive printed circuit boards that need to withstand these corrosive fluids, Dymax light-cure conformal coatings might be the right choice. For guidance on the best chemistry and equipment solution for your assembly contact our Application Engineering team.

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