HumiSeal®️ UV500 is a high solids, dual UV-curable elastomeric acrylate conformal coating. It provides excellent flexibility, moisture resistance, electrical insulation properties, and good chemical resistance.
HumiSeal®️ UV500 has been specifically developed to offer the following features:
• Cures tack-free using microwave or arc UV light
• Includes a secondary curing mechanism that fully cures areas not exposed to light within 7 days under ambient conditions
• Offers higher flexibility compared to other UV-curable conformal coatings and performs better in thermal cycling tests
• Fluoresces under UV light to enable coating inspection
• Can be applied with all selective coating equipment
• Provides excellent chemical and moisture resistance
HumiSeal®️ UV500 complies with the following standards:
• IEC 60664-3
• Compliant with REACH and RoHS Directive EU 2015/863
• Compliant with China RoHS 2
• Compliant with China Standard GB30981-2020
• Approved under UL File Number E105698
Properties of HumiSeal®️ UV500:
Density: 1.0 to 1.1 g/cm³
Minimum Solids Content: 98%
Viscosity: 275 to 375 centipoise
Recommended coating thickness: 75–130 microns
Recommended UV curing: See curing section below
Shelf life at room temperature: 9 months
Recommended remover**: HumiSeal®️ Stripper 1100
Thermal shock (50 cycles according to MIL-I-46058C): -65°C to 125°C
Flammability: UL-94 V-0
Conformal coatings can be successfully applied to surfaces that have been cleaned prior to coating, as well as to surfaces assembled using low-residue, “no-clean” materials. Users should perform the necessary testing to verify compatibility between the conformal coating and their specific assembly materials, process conditions, and cleanliness levels.
Curing:
HumiSeal®️ UV500 is a highly cross-linked coating material. To achieve maximum cross-link density, the product must be exposed to the correct spectral irradiation. HumiSeal has modeled the performance of UV500 using arc and microwave-based UV curing equipment. The table below summarizes the dosage and irradiation levels required to eliminate tackiness of HumiSeal®️ UV500 after UV exposure with both types of equipment. Minimum values should provide a tack-free surface. The maximum recommendations represent the highest values tested by HumiSeal. Curing recommendations may change as curing technologies evolve.
| | Dose J/cm2 * | Irradiance W/cm2 * |
|---|
| | UVA | UVB | UVC | UVA | UVB | UVC |
|---|
| Min | Arc System |
1.5 |
1.5 |
0.40 |
0.50 |
0.50 |
0.10 |
|---|
| Min | Microwave System |
2.0 |
2.0 |
0.40 |
0.70 |
0.70 |
0.15 |
|---|
| Max | Arc System |
2.8 |
2.7 |
0.80 |
0.90 |
0.80 |
0.20 |
|---|
| Max | Microwave System |
3.0 |
3.0 |
0.60 |
1.15 |
1.15 |
0.24 |
|---|
Heat is also an important factor in the UV curing process, and different systems generate varying levels of heat output. Higher heat levels can enable UV curing at lower dose/irradiance levels. Therefore, HumiSeal®️ recommends consulting with its technical team to ensure that the curing process fully meets the coating requirements of the customer’s process. After exposure to UV radiation and once returned to room temperature, the coating should not exhibit any tackiness.
HumiSeal®️ UV500 includes a reliable secondary moisture cure mechanism that will cure shadowed areas on the assembly within 7 days under ambient humidity.
HumiSeal®️ UV500 is designed to be cured using a microwave UV oven equipped with an “H” type bulb. Arc systems can cure HumiSeal®️ UV500; however, care must be taken during equipment selection to ensure that the achieved minimum dose and irradiance values are sufficient for proper curing. Due to potential variations in curing equipment type and configuration, it is strongly recommended to discuss your specific equipment and process in detail.
Cleaning:
Alcohol-free solvents should be used to clean equipment and remove uncured material. The use of HumiSeal®️ Thinner 521 or Thinner 521EU is recommended.
Rework
HumiSeal®️ UV500 is a highly cross-linked, UV-cured coating. The cured film exhibits a high level of environmental and chemical resistance and is more difficult to remove than conventional conformal coatings. Thermal displacement and mechanical abrasion are suitable options for reworking HumiSeal®️ UV500.
Storage
Light-sensitive. The product should not be exposed to direct sunlight or full-spectrum fluorescent light. To maximize shelf life, store in a cool place below 20°C. Before use, allow the product to equilibrate at room temperature for 24 hours. It is a moisture-curing material, and care should be taken to protect process containers and partially filled containers from moisture. Partially filled containers should be purged with a dry, inert gas such as dry air, nitrogen, or argon before sealing; otherwise, premature polymerization may occur due to atmospheric moisture.
