Urethanes Conformal coating 1A20
Model No: 1A20

HumiSeal® 1A20 is a single component, chemically resistant, fast curing polyurethane conformal coating. HumiSeal® 1A20 fluorescence under UV light for ease of inspection.

 Product Enquiry

HumiSeal® 1A20 conformal coating is:

  • Urethane chemistry
  • fast curing, chemically resistant
  • single component
  • used in combination with Thinner 521
  • RoHS Directive 2002/95/EC compliant
  • Recognized under UL File Number E105698.


HumiSeal® 1A20 conformal coating has:

  • excellent moisture and environmental protection for printed circuit assemblies
  • fluorescence under UV light for ease of inspection
  • MIL-I-46058C qualified
  • IPC-CC-830 compliance
  • RoHS Directive 2015/836/EU

Although its formulation allows HumiSeal® 1A20 to be applied using a wide variety of methods, care should be taken to ensure that it is only applied in an environment where the ambient relative humidity is at 60% or less. Application of the coating when the RH is higher than 60% can cause acceleration of the cure reaction, resulting in bubbles in the dried film.

Application of HumiSeal® 1A20 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” materials. Users should perform adequate testing to confirm compatibility between the conformal coating and their particular assembly materials, process conditions and cleanliness level.


Product Specification

Density, per ASTM D1475

1.02 ± 0.02 g/cm3

Solids Content, % by weight per Fed-Std-141, Meth. 4044

50 ± 3 %

Viscosity, per Fed-Std-141, Meth. 4287

100 ± 30 centipoise



Recommended Coating Thickness

25 -75 microns

Drying Time to Handle per Fed-Std-141, Meth. 4061

60 minutes

Recommended Curing Conditions

24 hrs @ RT or 3 hrs @ 76°C

Time Required to Reach Optimum Properties

7 days

Thinner, if needed (dipping, brushing, spraying)

 HumiSeal® Thinner 521, 521EU

Recommended Stripper

 HumiSeal® Stripper 1072

Shelf Life at Room Temperature, DOM

 6 months

Thermal Shock, per MIL-I-46058C

 -65°C to 125°C

Coefficient of Thermal Expansion – TMA

515 ppm/°C

Glass Transition Temperature – DSC


Modulus – DMA

 89.6 MPa

Flammability, per UL94


Dielectric Withstand Voltage, per MIL-I-46058C

 >1500 volts

Dielectric Constant, at 1MHz and 25°C per ASTM D150-98


Dissipation Factor, at 1MHz and 25°C per ASTM D150-98


Insulation Resistance, per MIL-I-46058C

3.0 x 1014 ohms (300TΩ)

Moisture Insulation Resistance, per MIL-I-46058C

 4.8 x 1010 ohms (48GΩ)

Fungus Resistance, per ASTM G21


Resistance to Chemicals