Dow DOWSIL CC-2588 Conformal Coating

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

The conformal coating cures without ovens to form a tough, scratch-resistant surface. With a durometer of 76 Shore A, the coating offers good mechanical strength to resist damage. It also provides adhesion without the delamination associated with acrylate conformal coatings and the darkening associated with polyurethane products. At room temperature, the coating has 5 min of tack time to support assembly adjustments before permanent bonding occurs.

Designed for harsh environments, the coating combines a UL 94 V-0 flammability rating with good electrical properties and meets IPC-CC-830B, Amendment 1 requirements for insulation resistance and dielectric withstanding voltage. It is formulated to have a high concentration of solid components and can readily dry to a film thickness of 50 to 200 µm in a single spray. This high solid content virtually eliminates bubbles (<10 min) that, in previous conformal coatings, caused voids and exposed substrates to contamination. When dispensed, the conformal coating has a viscosity that is easy to lower by adding DOWSIL OS-20 Silicone Fluid, which is also essentially odourless.

The 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, the coating may keep coils from loosening and provide cushioning against stress.