HumiSeal - Model 1B31 -Conformal Coating

Application of 1B31 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. Please contact a HumiSeal representative for additional information.

Dipping
Depending on the complexity, density and configuration of components on the assembly, it may be necessary to reduce the viscosity of HumiSeal 1B31 with HumiSeal Thinner 503 in order to obtain a uniform film. Once optimum viscosity is determined, a controlled rate of immersion and withdrawal (typically, 5 to 15 cm/min) will further ensure even deposition of the coating and provide a uniform film. During application, evaporation of solvent causes an increase in viscosity that should be adjusted by adding small amounts of HumiSeal® Thinner 503. Viscosity in the dip tank should be checked regularly using a simple measuring device, such as a Zahn or Ford viscosity cup.

Spraying
HumiSeal 1B31 can be sprayed using conventional spraying equipment. Spraying should be done in an environment with adequate ventilation so that vapor and mist are carried away from the operator. The addition of HumiSeal® Thinner 521 or 521EU is necessary to ensure a uniform spray pattern resulting in a pinhole-free film. The amount of thinner and spray pressure will depend on the specific type of spray equipment and operator technique. The recommended ratio of HumiSeal 1B31 to HumiSeal Thinner 521or 521EU is 1:1 by volume; however, the ratio may need to be adjusted to obtain a uniform coating.

Brushing
HumiSeal 1B31 may be brushed with a small addition of HumiSeal Thinner 503. Uniformity of the film depends on the component density and operator technique.

Density, per ASTM D1475: 0.91 ± 0.02 g/cm3
Solids Content, % by weight per Fed-Std-141, Meth. 4044: 35 ± 3 %
Viscosity, per Fed-Std-141, Meth. 4287: 200 ± 15 centipoise
VOC: 592 grams/liter
Drying Time to Handle per Fed-Std-141, Meth. 4061: 10 minutes
Recommended Coating Thickness: 25 – 75 microns
Recommended Curing Conditions: 24 hrs @ RT or 30 min @ 76°C
Time Required to Reach Optimum Properties: 7 days
Recommended Thinner (dipping & brushing): HumiSeal Thinner 503
Recommended Thinner (spraying): HumiSeal Thinner 521, 521EU
Recommended Stripper: Stripper 1080, 1080EU
Shelf Life at Room Temperature, DOM: 24 months
Thermal Shock, 50 cycles per MIL-I-46058C: -65°C to 125°C
Coefficient of Thermal Expansion – TMA: 170 ppm/°C below Tg340 ppm/°C above Tg
Glass Transition Temperature – DSC: 14°C
Modulus – DMA: 2000 MPa @ -40°C1050 MPa @ 20°C8.5 MPa @ 60°C
Flammability, per MIL-I-46058C: Self-Extinguishing
Dielectric Withstand Voltage, per MIL-I-46058C: >1500 volts
Dielectric Breakdown Voltage, per ASTM D149: 7500 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: 8.0 x 1014 ohms (800TΩ)
Moisture Insulation Resistance, per MIL-I-46058C: 6.0 x 1010 ohms (60GΩ)
Fungus Resistance, per ASTM G21: Passes