HumiSeal 1B73-11.5-OZ, Type 1B73 Acrylic Conformal Coating, Clear, 11.5 Oz.
HumiSeal 1B73-11.5-OZ, Type 1B73 Acrylic Conformal Coating, Clear, 11.5 oz
HumiSeal 1B73 is a single-component, fast-drying acrylic conformal coating providing excellent moisture and environmental protection for printed circuit assemblies. UV fluorescent for easy inspection, easily reworkable, and qualified to MIL-I-46058C and IPC-CC-830. UL recognized under File Number E105698. RoHS directive 2015/863/EU compliant. Compatible with cleaned substrates and low-residue no-clean assemblies.
Key Specifications
| Property | Value | Test Method |
|---|---|---|
| Part Number | 1B73-11.5-OZ | — |
| Chemistry | Acrylic, single-component | — |
| Volume | 11.5 oz | — |
| Density | 0.92 ± 0.02 g/cm³ | ASTM D1475 |
| Solids Content | 29.5 ± 2% by weight | Fed-Std-141, Meth. 4044 |
| Viscosity | 250 ± 20 centipoise | Fed-Std-141, Meth. 4287 |
| VOC | 661 g/L | — |
| Dry to Handle | 30 minutes | Fed-Std-141, Meth. 4061 |
| Recommended Coating Thickness | 25–75 microns | — |
| Cure: Room Temperature | 24 hrs @ RT | — |
| Cure: Accelerated | 2 hrs @ 76°C | — |
| Time to Optimum Properties | 7 days | — |
| Shelf Life | 24 months from DOM | — |
| Recommended Thinner | HumiSeal Thinner 73 | — |
| Recommended Stripper | HumiSeal Stripper 1080 / 1080A | — |
| Thermal Shock | -65°C to 125°C, 50 cycles | MIL-I-46058C |
| CTE (TMA) | 67 ppm/°C | — |
| Glass Transition Temp (DSC) | 42°C | — |
| Modulus (DMA) | 11.1 MPa | — |
| Flammability | UL 94 V-0 | UL 94 |
| Dielectric Withstand Voltage | >1,500 V | MIL-I-46058C |
| Dielectric Breakdown Voltage | 6,300 V | ASTM D149 |
| Dielectric Constant (1 MHz, 25°C) | 2.6 | ASTM D150-98 |
| Dissipation Factor (1 MHz, 25°C) | 0.010 | ASTM D150-98 |
| Insulation Resistance | 5.5 × 10¹⁴ Ω (550 TΩ) | MIL-I-46058C |
| Moisture Insulation Resistance | 7.0 × 10¹⁰ Ω (70 GΩ) | MIL-I-46058C |
| Fungus Resistance | Passes | ASTM G21 |
| Certifications | MIL-I-46058C, IPC-CC-830, UL E105698, RoHS 2015/863/EU | — |
Application Methods
Dipping: Reduce viscosity with HumiSeal Thinner 503 as needed for complex assemblies. Immerse and withdraw at 5–15 cm/min for uniform film. Monitor and adjust viscosity with Thinner 73 during use.
Spraying: Use conventional spray equipment with adequate ventilation. Recommended ratio: 1:1 by volume with HumiSeal Thinner 73. Adjust ratio and spray pressure to achieve a pinhole-free film.
Brushing: Apply with a small addition of HumiSeal Thinner 73. Film uniformity depends on component density and operator technique.
Frequently Asked Questions
Is HumiSeal 1B73 compatible with no-clean assemblies?
Yes — 1B73 can be applied to substrates assembled with low-residue no-clean materials. HumiSeal recommends performing adequate testing to confirm compatibility with your specific assembly materials, process conditions, and cleanliness level.
What thinner and stripper are recommended for 1B73?
The recommended thinner is HumiSeal Thinner 73 (or 730EU). For removal, use HumiSeal Stripper 1080 or 1080A.
How long does 1B73 take to reach optimum properties?
1B73 is dry to handle in 30 minutes. Full cure is 24 hours at room temperature or 2 hours at 76°C. Optimum electrical and mechanical properties are reached after 7 days.
Does 1B73 fluoresce under UV light?
Yes — 1B73 is UV fluorescent, enabling easy automated or manual inspection of coating coverage.
