M78-3068UV UV/Moisture Dual-Cure Conformal Coating
Product Applications:
M78-3068UV is a one-component UV/moisture dual-cure conformal coating designed to protect printed circuit boards (PCBs), thick-film circuits, porous substrates, and related electronic assemblies.
The coating cures rapidly when exposed to UV light. In shadowed areas where UV light cannot fully reach—such as beneath components, around connectors, or within complex assemblies—it continues to cure through moisture exposure. This dual-cure mechanism helps provide reliable coating coverage across complex PCB designs.
After curing, M78-3068UV forms a durable protective layer that helps shield electronic circuits and components from moisture, dust, corrosion, and other environmental contaminants. It is an ideal conformal coating solution for PCB protection, electronic assembly protection, and applications requiring dependable curing in UV-shadowed areas.
- Description
- Technical Data
- FAQ
Description
Product Features:
· UV/moisture dual cure
· Low odor, non-irritating; no benzene, acetone or other toxics
· Moisture/mildew/salt-spray proof, insulating; resistant to acid/alkali, sulfurization, heat & humidity, thermal shock
· Fast curing, no VOCs, no HAPs
· Fluorescent tracer for easy inspection
· Flame retardant, UL94-V0
· Complies with ROHS, REACH, HF and other environmental requirements
· Cures to form a tough, wear-resistant surface coating
Physical Properties：
| Item | Unit | Value | Test Method |
| Appearance | —— | Colorless to pale yellow transparent liquid | Visual |
| Non-volatile content | % | 100 | – |
| Density | g/cm3 | 1.0~1.1 | GB/T 13354-92 |
| Viscosity | mPa.s | 180±30 | GB/T 1723-1993 |
| UV curing condition | mJ/cm2 | 1000-2000 | 320-405nm |
| Moisture curing condition | h | 24～72 | 25℃, 50%RH |
| Storage time | month | 6 | 0-30℃ |
Post-Cure Properties：
| Hardness | Shore D | 75-90 | GB/T 531.1 |
| Tensile Strength | MPa | 22 | GB/T 528 |
| Elongation at Break | % | 4 | GB/T 528 |
| Water Absorption | % | ≤0.3 | – |
| Volume Resistivity | Ω·cm | 2.6×1016 | GB/T 1692 |
| Dielectric Strength | kV/mm | 75 | GB/T 1693 |
| Dielectric Constant | 1MHz | 3.25 | GB/T 1693 |
| Dissipation Factor | 1MHz | 0.01 | GB/T 1693 |
| Adhesion
| Cross-cut test | Grade 0 | GB/T9286-1998 Cross-cut test for paints and varnishes |
| Salt Spray Resistance | 35℃, 5% NaCl, 172 h | No blistering, peeling, wrinkling or other defects; no substrate corrosion. | GB/T 2423.17-2008, Test Ka: Salt mist |
| High Temp & Humidity Aging | 85℃, 85%RH, 10 days | No wrinkling, chalking, peeling or reversion to liquid of the film | Enterprise standard |
| High/Low Temp Shock Test | -45℃/30 min, 135℃/30 min, 100 cycles | No delamination, wrinkling, blistering, peeling or cracking of the film | IPC-CC-830B-2002 Qualification & Performance of Insulating Compound for PCB Assemblies |
Operating Temperature & Environmental Compliance：
· The cured product is typically used in the range of -55℃ to +125℃; depending on the application, other limits may be more appropriate.
· Complies with RoHS, REACH
· Cl, Br <700 ppm.
Process & Precautions：
· Surface cleaning
For the best bonding performance, the surface to be bonded must be dry and free of dust, grease and other contaminants;
· Application
Any of spraying, dip coating or brushing may be chosen; carry out application tests before use for more convenient application.
· Curing
The UV curing rate depends on lamp intensity, distance between light source and coating, required curing depth or coating gap, and substrate light transmittance;
Use UV or visible light with a wavelength range of 320-420 nm;
| Lamp Type | UV Curing Lamp | |||
| λ [nm] | 320 | 365 | 395 | 405 |
| Suitability | – | ++ | + | – |
（- unsuitable + suitable ++ very suitable）
| Typical Curing Performance | |
| Recommended UV curing condition (s) High-pressure Hg lamp, intensity (30-50 mW/cm²) | 20-25 |
| Recommended moisture curing condition (h) 70% RH @ 25℃ | 72 |
The above are recommended curing conditions. Actual conditions may vary with customer experience, application requirements and curing equipment.
· Tack-free curing of exposed surfaces needs high UV intensity (min. 500 mW/cm²); a 1000 mW/cm² mercury/electrodeless lamp usually gives better surface drying.
· Shadowed areas moisture-cure; ≥2-3 days recommended (25℃/50%RH). Higher temperature/humidity shortens curing; lower prolongs it.
Precautions:
· This product is UV-sensitive; avoid exposure to daylight, UV and artificial light sources during storage and handling.
· After application, immediately tighten the cap of any unused product and store it sealed. On re-use, if slight skinning has formed at the seal, simply remove it — normal use is not affected.
Packaging & Transport
· Packaging
1 KG/pail, 4 KG/pail
· Storage
Store sealed in a dark, cool, dry, ventilated place; shelf life 6 months from production. Products past shelf life should be confirmed normal before use.
· Transport
Transport as a special chemical per national laws and regulations.
Frequently Asked Questions
What is the minimum order quantity (MOQ) for M78-3068UV?
The standard MOQ for M78-3068UV is 4 kg per order. For trial orders below the standard MOQ, please contact us for sample availability and a customized quotation.
What packaging options are available?
M78-3068UV is available in the following standard packaging options:
- 1 kg per pail
- 4 kg per pail
Please contact us for bulk orders, customized packaging, OEM labels, or special packing requirements.
Can I request a sample before placing a bulk order?
Yes. Free samples are available for quality evaluation and application testing. Please contact us to confirm the sample quantity and availability. Shipping costs are the responsibility of the customer.
What is M78-3068UV used for?
M78-3068UV is a one-component UV/moisture dual-cure conformal coating used to protect printed circuit boards (PCBs), thick-film circuits, porous substrates, and related electronic assemblies from moisture, dust, corrosion, and other environmental contaminants.
How does the UV/moisture dual-cure system work?
The coating cures rapidly in UV-exposed areas. In shadowed areas where UV light cannot reach completely—such as beneath components, around connectors, or inside complex circuit-board assemblies—it continues curing through exposure to atmospheric moisture. This helps provide reliable protection across complex PCB designs.
Is M78-3068UV suitable for shadowed areas on PCBs?
Yes. M78-3068UV is specifically designed for electronic assemblies with UV-shadowed areas. Its moisture-curing mechanism supports curing in areas that receive limited or no direct UV exposure.
What application methods can be used?
M78-3068UV may be suitable for selective coating, spraying, brushing, dipping, or dispensing, depending on the equipment, coating thickness, and process requirements. Please contact our technical team for application recommendations for your production line.
What UV curing equipment is recommended?
The appropriate UV curing equipment, wavelength, light intensity, and exposure time depend on the coating thickness, PCB design, component layout, and production conditions. Contact us for technical guidance and recommended curing parameters.
How should the conformal coating be stored?
Store M78-3068UV in a cool, dry place away from direct sunlight, moisture, heat sources, and UV light. Keep the pail tightly closed when not in use. Please refer to the Technical Data Sheet (TDS) and Safety Data Sheet (SDS) for detailed handling and storage requirements.
What is the shelf life of M78-3068UV?
The shelf life is 6 months shelf life if unopened. when stored under recommended conditions. Please refer to the product label or contact us for batch-specific information.
Does M78-3068UV meet environmental compliance requirements?
M78-3068UV complies with applicable RoHS, REACH, and halogen-free requirements. Technical and compliance documents, including TDS, SDS, COA, and available declarations, can be provided upon request.
Do you provide technical support and customized solutions?
Yes. Our technical team can help with conformal-coating selection, PCB substrate compatibility, curing-process optimization, coating-thickness recommendations, and customized packaging solutions.