UV Curable UV40

HumiSeal® UV40 conformal coating is:

  • single component
  • high solids
  • UV curable
  • acrylated polyurethane

HumiSeal UV40 conformal coating has:

  • excellent chemical resistance, surface hardness, flexibility and moisture resistance.
  • secondary moisture cure mechanism for curing in the non-UV exposed shadowed areas
  • fluoresces under UV light to allow for coating inspection
  • can be applied by selective coating equipment.
  • recognized under UL File Number E105698
  • MIL-I-46058C qualified
  • IPC-CC-830
  • RoHS directive 2015/863/EU
  • China Standard GB30981-2020
  • ISO 10993-5 certified product

Application of UV40 Conformal Coating

Conformal coatings can be successfully applied to substrates that have been cleaned prior to coating and also to substrates assembled with low residue, “no clean” assembly materials. Users should perform adequate testing to confirm compatibility between the conformal coating and their particular assembly materials, process conditions and cleanliness level. Please contact HumiSeal® for additional information.

HumiSeal® UV40 can be applied via standard selective coating equipment or by conventional hand spray equipment. The source air used for spraying must be dry (a dry inert gas is highly recommended) to prevent premature curing of the secondary cure mechanism.  The spraying should be done with adequate ventilation so that the vapor and mist are carried away from the operator. 

HumiSeal® UV40 may be applied by brush for rework or touch up only. Brush must be cleaned with solvent promptly after use.

Clean Up
To flush equipment and clean uncured HumiSeal® UV40, non-alcohol based solvents should be used. HumiSeal® Thinner 521 or Thinner 521EU is recommended.

HumiSeal® UV40 is a highly cross linked UV cured coating.  The cured film has a high degree of environmental and chemical resistance and will be more difficult to remove than traditional conformal coatings.  Thermal displacement, mechanical abrasion and, where available, HumiSeal® Stripper 1100 are suitable options for rework of HumiSeal® UV40. 

Product Specification
Density 1.10 ± 0.05 g/cm3
Minimum Solids Content 95 %
Viscosity, per Fed-Std-141, Meth. 4287 650 ± 150 centipoise
Recommended Coating Thickness 25 – 125 microns
Recommended UV Cure* SeeTDS for Details
Shelf Life at Room Temperature, DOM 12 months
Recommended Stripper** HumiSeal® Stripper 1100
Thermal Shock, 50 cycles per MIL-I-46058C -65°C to 125°C
Glass Transition Temperature – DSC 45°C
Coefficient of Thermal Expansion – TMA 85 ppm/°C Below Tg
197 ppm/°C Above Tg
Modulus – DMA 10360 MPa @ -40ºC
4280 MPa @ 25ºC
66 MPa @ 80ºC
Flammability, per UL-94 V-0
Dielectric Withstand Voltage, per MIL-I-46058C >1500 volts
Dielectric Constant, at 1MHz and 25°C per ASTM D150-98 2.5
Dielectric Constant, at 10MHz and 22°C per ASTM D2520 3.21
Dissipation Factor, at 1MHz and 25°C per ASTM D150-98 0.01
Insulation Resistance, per MIL-I-46058C 8.0 x 1014 ohms (800TΩ)
Moisture Insulation Resistance, per MIL-I-46058C 4.7 x 1010 ohms (47GΩ)
Fungus Resistance, per ASTM G21 Pass
Resistance to Chemicals Excellent
*Microwave UV cure ovens equipped with “H” style bulbs recommended
**Stripper 1100 is not available in the EU
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