Dow launches new conformal coating for harsh environments, greater sustainability

Dow has introduced new DOWSIL™ CC-2588 Conformal Coating, a tough, abrasion-resistant silicone-based material that protects printed circuit boards (PCBs) and electronic components against high humidity and corrosion. This highly reliable silicone-based coating is virtually odourless and offers extremely low volatile organic compounds (VOCs). DOWSIL™ CC-2588 Conformal Coating cures at room temperature for reduced energy consumption, supports spraying for higher throughputs and enables automated inspection equipment to use ultraviolet light (UV) to identify any voids in the conformal coating.

"Dow’s silicone-based conformal coatings can resist extremely harsh environments while supporting environmental sustainability and manufacturing productivity,” said Tong Wu, Industrial Electronics, Global Segment Leader at Dow. "New DOWSIL™ CC-2588 Conformal Coating has an attractive balance of properties and is an important addition to our portfolio because it addresses customer needs and industry trends in PCB manufacturing and assembly.”

New DOWSIL™ CC-2588 Conformal Coating cures without ovens to form a tough, scratch-resistant surface. While traditional silicones offer resistance to humidity, high temperatures and chemicals, they may lack abrasion resistance because of their rubbery nature. However, Dow’s new DOWSIL material, once cured, is comparable to other resin conformal coatings in terms of toughness. With a durometer of 76 Shore A, it offers good mechanical strength to resist damage. It also provides reliable adhesion without the delamination associated with acrylate conformal coatings and the darkening associated with polyurethane products. At room temperature, itg has five minutes of tack time to support assembly adjustments before permanent bonding occurs.

Designed for harsh environments, DOWSIL™ CC-2588 Conformal Coating combines a UL 94 V-0 flammability rating with excellent electrical properties. Lab testing demonstrates that this protective coating meets IPC-CC-830B, Amendment 1 requirements for insulation resistance and dielectric withstanding voltage. Insulation resistance testing measures the total resistance between any two points separated by electrical insulation and, therefore, determines the effectiveness with which a test specimen resists the flow of electrical current. Dielectric withstanding voltage testing applies a voltage that is higher than the operating voltage across the thickness of a test specimen’s dielectric layer, thus demonstrating the specimen’s ability to withstand power surges and other increases in voltage.

The new Dow conformal coating is formulated to have a high concentration of solid components and can readily dry to a film thickness of 50-200μm in a single spray. This higher solid content virtually eliminates bubbles (<10min) that, in previous conformal coatings, caused voids and exposed substrates to contamination. Further, when dispensed, DOWSIL™ CC-2588 Conformal Coating has a viscosity that is easy to lower by adding DOWSIL™ OS-20 Silicone Fluid, which is also essentially odourless.

DOWSIL™ CC-2588 Conformal Coating provides the dielectric insulation, vibration dampening and moisture protection needed in PCB manufacturing and assembly for automotive electronics and household appliances. In network transformers, DOWSIL™ CC-2588 Conformal Coating may keep coils from loosening and provide cushioning against stress.

DOWSIL™ CC-2588 Conformal Coating is available worldwide through Dow and its extensive network of distribution partners.

To learn more, visit Dow www.dow.com