Components for automotive sound systems have to keep working in a wide range of temperatures, from -20 F to 150 F. Condensation buildup related to temperature fluctuations can wreak havoc on audio electronics. Conformal coatings protect automotive electronics from such damage.
Applying coating materials is not a matter of simply dipping a board into a coating material or spraying it onto boards. Circuit board assemblies are complex. Many are double-sided, and some areas cannot be coated. One manufacturer found a solution with an automated coating system.
The manufacturer had automated the conformal coating process, but overspray was a problem. If the coating is applied to areas where it shouldn’t be, it can cause latent field failures if not completely cleaned from the assembly. To prevent that from happening, the assemblies had to be masked and unmasked manually. This added time and labor cost to the production process.
A two-headed automated coating system from Specialty Coating Systems Inc. (Indianapolis) solved the problem. The system is equipped with a spray head for covering large areas quickly and an articulated needle valve for precision work. With the new system, connectors, switches, test points and other areas remain free of the coating, while sensitive areas are completely coated. The new system has eliminated the need to mask the boards.
The customer’s boards are assembled in a range of sizes. Some have high-profile components and very tight spacing. The coating heads on the new system move simultaneously in all three axes, with angular deflection of up to 30 degrees to reach all surfaces on a board. Automated two-sided selective coating is also possible.
The spray head can apply a round or flat pattern for general coverage, while the needle valve applies coating in deep recesses and around tall components. The system switches between dispensers on the fly. Motion resolution is 0.005 millimeter, and repeatability is ±0.025 millimeter.
For more information on conformal coating equipment, call 800-356-8260 or click here.