DOWSIL™ 1-2620 Low VOC Conformal Coating
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features
- One-part silicone conformal coating
- Wide operating temperature range (-45°C to 200°C)
- UV indicator for inspection and process control
Product Description
DOWSIL™ 1-2620 Low VOC Conformal Coating is a one-part, solvent-borne silicone resin conformal coating designed for protective coating of rigid and flexible circuit boards and PCB system applications. It provides 350 cP viscosity, 80 Shore A hardness, and UV indicator support while supporting room-temperature moisture cure and optional mild heat acceleration after solvent flash-off. This makes it suitable for PCB assemblies requiring low-viscosity flow, dielectric protection, and abrasion-resistant coating performance, subject to application-specific testing and qualification.
Key features
- One-part silicone resin solution - supplied as a one-part conformal coating with no separate catalyst or hardener mixing step.
- Low viscosity - 350 cP viscosity supports flow and filling in narrow gaps and spaces on PCB assemblies.
- Moisture cure - cures at room temperature with a 15 minute tack-free time at 25°C and optional mild heat acceleration after solvent flash-off.
- Abrasion-resistant surface - cures to a firm elastoplastic coating with 80 Shore A hardness.
- Inspection support - contains a UV indicator to support visual or automated coating inspection.
- Recognized coating documentation - listed with UL 94 V-0, UL 746E, IPC-CC-830 Amendment 1, and MIL-I-46058C Amendment 7 in the supplied product data.
Applications
DOWSIL™ 1-2620 Low VOC Conformal Coating is suitable for electronics assemblies where low-viscosity silicone coating, circuit-board protection, and coating inspection are part of the application review.
- Rigid and flexible circuit boards: suitable for protective coating of printed circuit boards and PCB system applications.
- PCB assembly protection: supports environmental protection, corrosion resistance, and dielectric protection requirements.
- Narrow-gap coating areas: low viscosity supports flow and filling in tight spaces and complex board geometries.
- Thin-section encapsulation: suitable for thin protective coating applications where solvent-borne silicone flow is required.
Related resources
Technical Specifications
General Properties
Physical Properties
Electrical Properties
Thermal Properties
Additional Information
DOWSIL™ 1-2620 Low VOC Conformal Coating
DOWSIL™ 1-2620 Low VOC Conformal Coating is a one-part, translucent, low-viscosity silicone resin solution for protective coating of rigid and flexible circuit boards and PCB system applications. It is designed for applications requiring a firm, elastoplastic, abrasion-resistant surface after cure, low-viscosity flow into narrow spaces, UV inspection support, and reduced VOC positioning compared with DOWSIL™ 1-2620 Dispersion.
Low-viscosity coating with inspection support
- One-part silicone resin solution for protective circuit-board coating.
- 350 cP viscosity supports flow and filling in narrow gaps and spaces.
- Translucent clear cured appearance supports visual review of coated areas.
- UV indicator supports manual or automated coating inspection.
- Firm, elastoplastic, abrasion-resistant cured surface with 80 Shore A hardness.
- Low-VOC version of DOWSIL™ 1-2620 Dispersion.
Room-temperature moisture cure
Solvent-based RTV conformal coating selection table
Use this compact comparison to review DOWSIL™ solvent-based RTV conformal coating options by viscosity, non-volatile content, tack-free time, hardness, inspection method, and documented agency listing context. The highlighted row shows where DOWSIL™ 1-2620 Low VOC Conformal Coating fits when reduced-VOC positioning and low-viscosity flow into narrow gaps are part of the application review.
| Product and positioning | Viscosity / non-volatile content | Tack-free time at 25°C | Typical hardness | Inspection | Compliance | Selection basis |
|---|---|---|---|---|---|---|
| DOWSIL™ 1-2577 Conformal Coating Medium-viscosity, firm, abrasion-resistant standard solvent-borne coating |
950 cP / 72% | 7 min | 80 Shore A / 20 Shore D | UV indicator | UL 94 V-0; UL 746E; IPC-CC-830; MIL-I-46058C Amendment 7 | Select when a medium-viscosity, UV-inspectable coating with a firm abrasion-resistant surface is required. |
| DOWSIL™ 1-2577 Low VOC Conformal Coating Reduced-VOC, lower-odor version of 1-2577; medium viscosity |
1,050 cP / approximately 34% | 6 min | 85 Shore A / 25 Shore D | UV indicator | UL 94 V-0; UL 746E; IPC-CC-830 Amendment 1; MIL-I-46058C Amendment 7 | Select when the performance profile of 1-2577 is required together with reduced VOC content and lower odor. |
| DOWSIL™ 1-2620 Dispersion Low-viscosity standard solvent-borne coating for thinner coating, greater coverage per kilogram, and faster dispensing |
150 cP / 59% | 5 min | 80 Shore A / 25 Shore D | UV indicator | UL 94 V-0; UL 746E; IPC-CC-830; MIL-I-46058C Amendment 7 | Select when very low viscosity, flow, thin coating, material coverage, or dispensing speed is the primary process requirement. |
| DOWSIL™ 1-2620 Low VOC Conformal Coating Reduced-VOC, lower-odor version of 1-2620 Dispersion; low viscosity |
350 cP / approximately 31% | 15 min | 80 Shore A | UV indicator | UL 94 V-0; UL 746E; IPC-CC-830 Amendment 1; MIL-I-46058C Amendment 7 | Select when reduced VOC content and enhanced flow into narrow gaps and spaces are required. |
| DOWSIL™ CC-2570 Conformal Coating Non-fluorescent, medium-viscosity coating for improved optical performance |
1,000 cP / 72% | 7 min | 76 Shore A / 25 Shore D | No fluorescence | UL 94 V-0; UL 746E | Select when fluorescence must be avoided and a medium-viscosity coating is needed. |
| DOWSIL™ CC-2571 Conformal Coating Non-fluorescent, very-low-viscosity coating for improved optical performance |
75 cP / 55% | 15 min | 80 Shore A / 25 Shore D | No fluorescence | UL 94 V-0; UL 746E | Select when fluorescence must be avoided and maximum flow from this product group is required. |
Process points to confirm before qualification
- Apply to clean and dry substrates.
- Review flux residues, oils, dust, and process contamination before coating.
- Validate adhesion on the actual PCB laminate, solder mask, metals, and component surfaces.
- Review spray, brush, flow, dip, or automated pattern coating for the actual line.
- Use the 350 cP viscosity together with target wet-film thickness and keep-out areas.
- Confirm coating flow around component edges, leads, solder joints, vias, and narrow gaps.
- Allow sufficient solvent flash-off before applying mild heat.
- Use tack-free time as a handling indicator, not as final property confirmation.
- Use the UV indicator to support coating-presence inspection, then separately verify film thickness, adhesion, and electrical performance.
- Review local coating removal by mechanical means or suitable solvents where appropriate.
- Clean and dry the affected area before recoating.
- Confirm repaired-area adhesion and coating continuity before release.
Where DOWSIL™ 1-2620 Low VOC fits
Frequently asked questions about DOWSIL™ 1-2620 Low VOC Conformal Coating
What is DOWSIL™ 1-2620 Low VOC Conformal Coating used for?
It is used as a protective conformal coating for rigid and flexible circuit boards and PCB system applications, particularly where toughness, abrasion resistance, dielectric protection, and low-viscosity flow are part of the application review.
How does this coating cure?
DOWSIL™ 1-2620 Low VOC cures by atmospheric moisture at room temperature. Mild heat can be used to accelerate processing after sufficient solvent flash-off.
Which application methods are supported?
The supplied data set lists dip, spray, brush, flow, and automated pattern coating. Process fit should be confirmed against the target wet-film thickness, board layout, masking approach, and keep-out areas.
What does the UV indicator confirm?
The UV indicator supports inspection of coating presence. It should not be treated as proof of final dry-film thickness, full cure, adhesion, absence of defects, or long-term electrical reliability.
Is Low VOC the same as solvent-free?
No. DOWSIL™ 1-2620 Low VOC is a solvent-borne silicone resin solution. Review the current SDS before storage, handling, dispensing, curing, cleaning, transport, or waste disposal.





















