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ABchimie746E UV LED Soft UV Cure Conformal Coating
- Excellent adhesion
- UV‑fluorescent for easy inspection
- Certified UL94 V‑0 and UL746E
Product Description
ABchimie 746E UV LED is a transparent, single‑component, LED‑curable conformal coating engineered to protect PCBs exposed to harsh environments. It features dual‑cure technology (UV LED + humidity) for complete crosslinking, including areas shadowed from UV LED exposure.
Its optimized formulation cures rapidly under UV LED light sources, enabling energy‑efficient, low‑temperature, high‑speed manufacturing. With low viscosity designed for precise application around 80 µm, ABchimie 746E UV LED is ideal for advanced selective coating processes.
Product Key Features
- Excellent adhesion in harsh climatic and environmental conditions
- UV‑fluorescent for easy inspection of coating uniformity
- Operating temperature range: –65°C to +150°C
- Safe solder‑through performance without toxic gas formation
- Certified UL94 V‑0 and UL746E (QMJU2‑E308681)
Applications
- High‑volume production lines requiring instant UV LED curing
- Complex assemblies with shadowed areas requiring dual‑cure reliability
Technical Specifications
| General Properties | |
| Appearance Appearance Appearance at room temperature. | Transparent yellow liquid |
| Film Thickness Film Thickness Film thickness is the thickness of a backing film without taking into account any coatings or adhesive layers. It is measured in micron and the conversion factor to mil is 0.039. | 30 - 150 µm |
| Physical Properties | |
| Viscosity Viscosity Viscosity is a measurement of a fluid’s resistance to flow. Viscosity is commonly measured in centiPoise (cP). One cP is defined as the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP. A product like honey would have a much higher viscosity -around 10,000 cPs- compared to water. As a result, honey would flow much slower out of a tipped glass than water would. The viscosity of a material can be decreased with an increase in temperature in order to better suit an application | 0.05 - 0.1 mPa.s |
| Electrical Properties | |
| Breakdown Voltage Breakdown Voltage Breakdown voltage is the minimum voltage necessary to force an insulator to conduct some amount of electricity. It is the point at which a material ceases to be an insulator and becomes a resistor that conducts electricity at some proportion of the total current. After dielectric breakdown, the material may or may not behave as an insulator any more because of the molecular structure alteration. The current flow tend to create a localised puncture that totally alters the dielectric properties of the material. This electrical property is thickness dependent and is the maximum amount of voltage that a dielectric material can withstand before breaking down. The breakdown voltage is calculated by multiplying the dielectric strength of the material times the thickness of the film. | 1750 V |
| Dielectric Strength Dielectric Strength Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material. Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property. As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow. | 60 kV/mm |
| Thermal Properties | |
| Coefficient of Thermal Expansion (CTE), α1 Coefficient of Thermal Expansion (CTE), α1 CTE α1 (alpha 1) is the slope of the Coefficient of thermal expansion in a temperature range below the Glass transition temperature (Tg). It explains how much a material will expand until it reaches Tg. | 200 ppm/°C |
| Coefficient of Thermal Expansion (CTE), α2 Coefficient of Thermal Expansion (CTE), α2 CTE α2 (alpha 2) is the slope of the Coefficient of thermal expansion in a temperature range above the Glass transition temperature (Tg). It explains the extent to which a material will expand after it passes Tg. | 250 ppm/°C |
| Glass Transition Temperature (Tg) Glass Transition Temperature (Tg) The glass transition temperature for organic adhesives is a temperature region where the polymers change from glassy and brittle to soft and rubbery. Increasing the temperature further continues the softening process as the viscosity drops too. Temperatures between the glass transition temperature and below the decomposition point of the adhesive are the best region for bonding. The glass-transition temperature Tg of a material characterizes the range of temperatures over which this glass transition occurs. | 12.5 °C |
| Operating Temperature | -65 - +150 °C |
| UL 94 Rating UL 94 Rating Flammability rating classification. It determines how fast a material burns or extinguishes once it is ignited. HB: slow burning on a horizontal specimen; burning rate less than 76 mm/min for thickness less than 3 mm or burning stops before 100 mm V-2: burning stops within 30 seconds on a vertical specimen; drips of flaming particles are allowed. V-1: burning stops within 30 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed. V-0: burning stops within 10 seconds on a vertical specimen; drips of particles allowed as long as they are not inflamed. 5VB: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may develop a hole. 5VA: burning stops within 60 seconds on a vertical specimen; no drips allowed; plaque specimens may not develop a hole | V-0 |
Additional Information
Frequently Asked Questions About ABChimie® 746E UV LED
What are typical applications for ABChimie® 746E UV LED?
ABChimie® 746E UV LED is a low viscosity UV-curable conformal coating designed to protect printed circuit board assemblies (PCBs) and components in demanding manufacturing environments, including:
- Automotive electronics (e.g., control units, sensors)
- Industrial automation (e.g., motor drives, PLCs)
- Consumer electronics (e.g., smart devices, wearables)
- Other high-reliability electronic assemblies
What safety precautions should I take?
Use ABChimie® 746E UV LED in a well-ventilated area, avoid skin and eye contact, and follow all Safety Data Sheet (SDS) guidelines. Keep away from open flames and sparks.
Can I adjust the viscosity?
ABChimie® 746E UV LED can be customized for variable viscosities. Contact our team for guidance.
Should I control the application environment?
ABChimie® 746E UV LED should be applied at a minimum temperature of 16°C and a minimum relative humidity of 50%. The relative humidity of at least 50% is recommended for the secondary polymerization. Before applying, the PCB must be clean, dry, and free of moisture. A stage in an oven at 80°C for 4 hours is usually sufficient.
Learn More About ABChimie® 746E UV LED
ABChimie® 746E UV LED is a proven solution for engineers seeking fast, reliable protection of electronic assemblies in demanding manufacturing environments. This UV-curable conformal coating delivers rapid curing, excellent electrical insulation, and strong environmental resistance—ideal for automotive, industrial, consumer, and high-reliability assemblies. It also contains a UV tracer for easy inspection.
Main Advantages of ABChimie 746E UV LED
ABChimie® 746E UV LED cures through a dual mechanism: UV exposure initiates rapid surface curing, while moisture ensures complete curing throughout the coating.
Provides excellent mechanical protection, resisting scratches, abrasion, and minor impacts to ensure long-term component stability.
Can be soldered through without generating highly toxic gases, maintaining coating integrity.
Provides strong adhesion in harsh conditions, resisting moisture, chemicals, and temperature changes.
How to Choose a Conformal Coating
- ✔ Norms & Compliance
- ✔ Environment / Exposure Conditions
- ✔ Repairability
- ✔ Electrical Performance
- ✔ Application Method
- ✔ Operating Temperature
Compliance You Can Trust ✅
- REACH Compliant
- RoHS 2011/65/EU Compliant
UL94 V0
UL746E (QMJU2-E308681)
Curing Tip: ABChimie 746E UV LED cures with UV rays. Use the recommended equipment and settings to achieve optimal properties.
Ref. Leistung / ref power ln % over wavelength in nm
Key Curing Properties
LED
395 nm
3000 mJ/cm2
Coating Thickness
100 μm
Minimum UVA Power
500 mW/cm2
Typical property values shown for reference only and should not be used as specifications.
How to Optimise for the Best Results
PCBs must be completely dry and thoroughly clean, with no dust, grease, wax, or other contaminants. All flux residues must be removed to prevent corrosion or malfunctions.
For cleaning equipment or removing uncured ABChimie 746E UV or UV LED varnish, use SND or ABclean solvent.
Use the correct UV equipment and recommended settings to achieve optimal properties. UV exposure plus moisture curing ensures complete polymerization.
Curing Mechanism: UV light creates the first cure, and after 7 days, the moisture from the environment completes the curing process.
How does Moisture Cure Work?
During UV curing, exposure to UV light activates the photoinitiators in the conformal coating, triggering rapid polymerization of the resin. This results in an immediate surface cure and fast development of handling strength. UV curing provides precise, on-demand curing in exposed areas, enabling high-throughput processing while maintaining coating uniformity.
ABChimie 746E UV and ABChimie 746E UV LED use the same dual curing mechanism to ensure complete curing, including in shadowed or hard-to-reach areas. Initial curing is achieved by UV exposure, while a secondary moisture-activated cure completes the process at ambient temperature. For full curing in shaded areas, a minimum relative humidity of 50% is required for at least 7 days.
ABChimie 746E UV LED is also available in the mercury lamp version, which cures with a mercury lamp.
ABChimie 746E UV [Go to 746E UV Product Page↗]
- Conformal Coating
- Fluorescent under UV light
- Excellent adhesion to flexible substrates
- Dual curing with UV light exposure and moisture curing
Best suited for: High-speed process using LED light for curing