Nano vacuum coating is to break parylene polymer materials into nano molecules and then perform vacuum coating on the surface of the product using vacuum vapor deposition equipment (CVD), so that the plated object has the following characteristics: no pinholes, waterproof, moisture-proof, acid and alkali resistant, salt spray resistant, high pressure insulation, biocompatibility, etc. Service areas include aerospace, military, automotive, motor, computer peripherals, Bluetooth headsets, smart water meters, LED, micro-electromechanical systems, medical soft panels, cultural relics preservation, and more.
Parylene is a new type of coating material developed and applied by Union Carbide Co. in the United States. According to different molecular structures, Parylene can be divided into N-type, C-type, D-type, HT-type and other types.
Parylene deposition can be polymerised on the surface of an object using active monomer gas, which differs from the general preparation method of liquid coating. Parylene is a completely coated film that polymerises active molecules on the surface of an object under vacuum conditions. It can be applied to surfaces of any shape without dead angles, including sharp edges, inside gaps and excellent pinholes. The film thickness can be consistently coated on any part of the product. The film thickness ranges from 1 μmm to 5 μmm, making it one of the thinnest coatings in the world.
Vacuum vapor deposition technology features
| Feature | Description |
|---|---|
| High Reliability | Suitable for military and commercial use; nearly zero outgassing. |
| IPX-8 Waterproof Rating | Withstands prolonged immersion in water without degradation. |
| Ultra-Thin Coating | Maintains original dimensions; thickness controllable from 5–30μm. |
| Room-Temperature Deposition | Coating applied at ambient temperature under vacuum conditions. |
| Wide Temperature Range | Operational from -200°C to +200°C. |
| High Transparency | Coating achieves optical-grade clarity. |
| True Conformal Coverage | Uniform coating on all surfaces with no variation in thickness. |
| Stress-Free Surface | No stress introduced to components; circuit sensitivity remains unaffected. |
| Low Friction Coefficient | Suitable as a dry-film lubricant. |
| Biocompatibility | Inert material; ideal for medical and biological applications. |
| Solvent Resistance | Coating is insoluble in common organic solvents. |
| Excellent Barrier Properties | Extremely low permeability to moisture and gases; effective shielding. |
| Chemical Resistance | Excellent resistance to acids and alkalis. |
| Anti-Mildew and Antimicrobial | Superior protection against mold and microbial growth. |
| Electrical Insulation | Highly non-conductive; strong resistance to dielectric breakdown. |
| Mechanical Strength | High tensile strength and yield resistance. |
| Surface Particle Control | Prevents particle shedding from product surfaces. |
LED waterproof experiment
To evaluate waterproof performance, two identical LED strips were selected—one treated with a conventional three-proof (conformal) coating, and the other with a Parylene nano vacuum coating. Both were submerged in water at the same time.
In the first stage, small air bubbles quickly formed around the traditionally coated strip, indicating water ingress, while the Parylene-coated strip remained unaffected.
To simulate harsher conditions, 9.9% salt solution was added to the water. The strip with the traditional coating began to corrode and dim within seconds. In contrast, the Parylene-coated strip maintained full brightness and stability.
After about 10 seconds, the traditionally coated LED experienced complete failure, with lights turning off and signs of electrical damage. The Parylene-coated strip continued to function normally, demonstrating its superior protection against moisture and corrosion.
This test highlights the unmatched waterproofing capabilities of Parylene coating, making it an ideal solution for critical applications in electronics, outdoor devices, and high-humidity environments.
Comparison table of electrical constants and dielectric loss data
| Property | Parylene N | Parylene C | Parylene D | Epoxy Resin (ER) | Silicone Resin (SR) | Polyurethane (UR) | Acrylic Resin (AR) | UV Resin |
|---|---|---|---|---|---|---|---|---|
| Dielectric Strength (V/mil) | 7000 | 5600 | 5500 | 900–1000 | 1100–2000 | 1400–3000 | 1200–2000 | — |
| Volume Resistivity (Ω·cm) | 1.4×10¹⁶ | 6.5×10¹⁶ | 1.2×10¹⁶ | 10¹³–10¹⁴ | 10¹²–10¹⁴ | 10⁹–10¹² | 10¹⁰–10¹³ | — |
| Surface Resistivity (Ω) | 10¹⁵ | 10¹⁴ | 10¹⁵ | 3.5×10¹¹ | 5.5×10¹¹ | 3×10⁸–3×10⁹ | 2×10⁹–3×10⁹ | — |
| Dielectric Constant (1kHz) | 2.65 | 3.10 | 2.84 | 3.3–5.5 | 3.5–4.0 | 5.0–7.0 | 2.5–5.5 | — |
| Dissipation Factor (1kHz) | 0.0002 | 0.0002 | 0.0005 | 0.002–0.006 | 0.001–0.005 | 0.002–0.010 | 0.003–0.006 | — |
| Dissipation Factor (1MHz) | 0.002 | 0.002 | 0.003 | 0.005–0.020 | 0.005–0.010 | 0.007–0.020 | 0.035–0.056 | — |
| Tensile Strength (MPa) | 69 | 70 | 75 | 28–40 | 20–30 | 15–25 | 10–20 | — |
| Elongation at Break (%) | 40 | 200 | 10 | 0.1–0.8 | 0.1–0.9 | 0.2–1.2 | 0.2–1.0 | — |
| Hardness | D35 | D80 | D85 | Shore D 80–100 | Shore A 40–45 | Shore A 20–25 | Shore A 15–25 | — |
| Thermal Resistance (°C) | 220 | 280 | 290 | 60–100 | 40–85 | 80–100 | 50–80 | — |
| Continuous Operating Temp (°C) | -200 to +120 | -200 to +100 | -200 to +140 | -84 to +199 | -55 to +110 | -55 to +130 | -59 to +137 | — |
| Moisture Absorption (%) | 0.06 | 0.06 | 0.04 | 3.5 | 3–8 | 25–30 | 10–20 | 0.5–15 |
| UV Resistance | Excellent | Excellent | Excellent | Poor | Poor | Poor | Moderate | Excellent |
Coating equipment
Coating application areas
Future development of micro-electromechanical semiconductors, silicone rubber, precision hardware, biotechnology medical equipment, cultural relics protection, magnetic material cores, circuit board LEDs, various test data and certifications