Water-base 1H20AR3-D

HumiSeal® 1H20AR3/D conformal coating is:

  • water-based
  • acrylic chemistry
  • fluoresces under UV light

HumiSeal 1H20AR3/D conformal coating has:

  • no VOCs or solvent
  • low toxicity
  • excellent environmental resistance and moisture resistance
  • RoHS Directive 2002/95/EC compliant

Application of 1H20AR3/D Conformal Coating

Cleanliness of the substrate is of extreme importance for the successful application of HumiSeal 1H20AR3/D. Surfaces must be free of moisture, dirt, wax, grease, flux residues and all other contaminants. 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.

Waterborne coatings should not be placed directly on bare/untreated steel. Applying waterborne coatings when the Relative Humidity is > 80% will adversely affect coating uniformity and can cause poor adhesion.

When HumiSeal® 1H2OAR3/D is first applied it has a milky white appearance. As the film dries, the white color fades until a clear, transparent film remains. The white color aids the operator’s coverage inspection and the color change serves as an indicator that the coating is dry to the touch. It is recommended that the coating is allowed to reach a tack-free condition before using heat to accelerate the cure process.


The material has been formulated for dip application as supplied and requires no thinning. Thinning will reduce the application performance and increase curing time substantially and is not recommended. Because it is a water-based coating, evaporation of HumiSeal® 1H2OAR3/D from the dip tank is very low. However, over a long period of time, the addition of a small amount of fresh HumiSeal® 1H2OAR3/D is beneficial, to replace the low level of coalescing solvents that are lost along with some water. The coalescing solvents are essential to provide optimum film formation and the other physical and electrical properties of the resin. A slightly slower immersion speed is recommended to reduce the possibility of air entrapment under the components. The withdrawal speed depends on the complexity of the assembly being coated. Although the material has been formulated to lay down 1.5 mils in a single dip application, for densely populated assemblies, reducing the withdrawal speed or applying two successive thinner coatings will give better edge coverage and a better coating appearance.

Properties of HumiSeal® 1H2OAR3/D

Density, per ASTM D1475 1.05 ± 0.05 g/cm³
Solids Content, % by weight per Fed-Std-141, Meth. 4044 44 ± 2 %
Viscosity, per Fed-Std-141, Meth. 4287 300 ± 100 centipoise
Recommended Coating Thickness 25 – 75 microns
Drying Time to Handle per Fed-Std-141, Meth. 4061 20 minutes
Recommended Curing Conditions 1 hr @ RT and 6 hrs @ 80°C
Time required to Reach Optimum Properties 7 days
Recommended Stripper HumiSeal® Stripper 1020
Pot Life at Room Temperature, DOM 6 months in dip tank
Shelf Life at Room Temperature, DOM 12 months
Thermal Shock, 50 cycles per MIL-I-46058C -65°C to 125°C
Temperature and Humidity Aging per IPC-TM-650 2.6.11 Pass
Flammability, per ASTM D-635 Self-extinguishing
Dielectric Withstand Voltage, per MIL-I-46058C >1500 volts
Dielectric Breakdown Voltage, per ASTM D149 6925 volts
Dielectric Constant, at 1MHz and 25°C per ASTM D150-98 2.5
Dissipation Factor, at 1MHz and 25°C per ASTM D150-98 0.01
Insulation Resistance, per MIL-I-46058C 2.3 x 1013 ohms (23 TΩ)
Moisture Insulation Resistance, per MIL-I-46058C 8.2 x 1010 ohms (82 GΩ)
Fungus Resistance, per ASTM G21 Passes

Other products in this chemistry include:

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