Parylene Conformal Coating | Ultra-Thin, Pinhole-Free PCBA Protection

Parylene conformal coating is the gold standard for high-reliability electronics. Unlike liquid coatings, Parylene is deposited as a dry polymer vapor at room temperature, creating an ultra-thin (5-25µm), pinhole-free, and chemically inert barrier that conforms perfectly to any substrate — including sharp edges, deep crevices, and complex 3D surfaces.

What Is Parylene Conformal Coating?

Parylene conformal coating is a unique, vacuum-deposited polymer film that provides complete, uniform protection for printed circuit boards and electronic assemblies. Unlike traditional spray, dip, or brush coatings, the deposition process — known as chemical vapor deposition (CVD) — occurs in a vacuum chamber at ambient temperature. The Parylene monomer gas polymerizes directly onto the substrate surface, creating a coating that follows every contour, even under components.

At Tengxinjie, we provide professional Parylene coating PCB services for medical devices, aerospace systems, military electronics, and other mission-critical applications where zero defects are required. Our Parylene PCBA process is fully qualified to industry standards, including IPC-CC-830 and MIL-I-46058C.

Parylene Conformal Coating

Why Choose Parylene for Electronics Protection?

🔬 Ultra-Thin & Pinhole-Free

Parylene conformal coating achieves complete coverage at thicknesses of just 5-25 microns — significantly thinner than liquid coatings. The vapor deposition process produces a film with no pinholes, cracks, or voids, even on sharp points or under components.

🧪 Chemically Inert & Biocompatible

Parylene for electronics offers exceptional resistance to solvents, acids, bases, and biological fluids. It is USP Class VI certified and ISO 10993 compliant, making it the standard choice for implantable medical devices and in-vivo sensors.

⚡ Superior Dielectric Properties

With a dielectric strength exceeding 7,000 volts per mil (275 kV/mm) and a stable dielectric constant (2.65 at 60 Hz), Parylene coating PCB provides excellent electrical insulation without signal distortion.

🌡️ Wide Temperature & Environmental Stability

Parylene performs reliably from -200°C to +125°C (and briefly up to +350°C in inert atmospheres). It resists UV degradation, moisture ingress (less than 0.1% water absorption), and outgassing, meeting NASA low-outgassing specifications for aerospace use.

Parylene Types: N, C, D, HT — Which One Is Right for You?

Parylene N (Poly-para-xylylene)

Highest dielectric strength and penetrating ability. Best for deep crevices, MEMS devices, and applications requiring the lowest dielectric constant.

Parylene C (Most Common)

Excellent combination of barrier properties, dielectric strength, and chemical resistance. Widely used for medical devices, PCBs, and general high-reliability electronics.

Parylene D

Higher thermal stability and chemical resistance than Type C. Suitable for high-temperature applications (up to 125°C continuous).

Parylene HT (High-Temperature)

Replaces CDC with fluorine substitution. Exceptional thermal stability (up to 450°C short-term) and UV resistance. Ideal for LED, automotive, and high-temperature sensors.

Parylene Conformal Coating Technical Specifications

Parameter	Parylene Coating Capability
Coating Types	Parylene N, Parylene C, Parylene D, Parylene HT (depending on application)
Deposition Method	Chemical Vapor Deposition (CVD) — room temperature, vacuum chamber
Typical Thickness	5 – 25 µm (0.2 – 1.0 mil) — up to 50 µm available upon request
Dielectric Strength	> 7,000 V/mil (275 kV/mm) for 5µm film
Dielectric Constant	2.65 at 60 Hz (Parylene C)
Water Absorption	< 0.1% (24-hour immersion)
Temperature Range	-200°C to +125°C continuous; higher for Parylene HT
Compliance	IPC-CC-830, MIL-I-46058C, USP Class VI, ISO 10993, NASA low-outgassing
Color	Water-clear / transparent

Critical Applications for Parylene PCBA Protection

🏥 Medical Devices

Implantable pacemakers, cochlear implants, neurostimulators, catheters, and surgical instruments. Parylene conformal coating is USP Class VI certified and biocompatible.

✈️ Aerospace & Defense

Avionics, navigation systems, missile guidance, satellites, and radar electronics. Parylene withstands extreme temperatures, vibration, and vacuum conditions.

🚗 Automotive & EV

Sensor modules, SDVs, battery management systems (BMS), and high-temperature power electronics. Parylene HT offers exceptional thermal stability.

📡 MEMS & Sensors

Pressure sensors, accelerometers, microphones, and microfluidic devices benefit from Parylene’s ultra-thin, conformal, and low-friction properties.

🔋 Energy Storage

Battery protection circuits, fuel cells, and supercapacitors benefit from Parylene’s chemical resistance and dielectric strength.

📱 Consumer Electronics

Wearables, hearables, smartwatches, and portable devices requiring reliable moisture and sweat protection without adding bulk.

Why Choose Tengxinjie for Parylene Coating?

✅ Dedicated Parylene Deposition Equipment

Our CVD chambers are sized for PCB panels and complex assemblies up to 24″ x 24″. We control deposition parameters precisely to achieve uniform thickness across every surface.

📋 Full Masking & Fixturing Capability

We provide precision masking for connectors, test points, and other keep-out areas using industry-proven tapes, boots, and selective removal techniques.

🔬 Quality Control & Documentation

Every batch includes thickness measurement (using eddy current or FTIR), adhesion testing, and pinhole inspection. Full documentation available for medical and aerospace compliance.

🌍 Global Regulatory Support

We support ISO 13485 (medical), IATF 16949 (automotive), AS9100D (aerospace) requirements, including First Article Inspection (FAI) and Certificate of Conformance (CoC).

Ready to Protect Your High-Reliability Electronics with Parylene?

Upload your PCB files, assembly drawings, and coating specifications. Our engineering team will review your requirements, recommend the optimal Parylene type (N, C, D, or HT), and provide a detailed quote within 24 hours.

Request a Parylene Quote →

✔ NDA Available ✔ ISO 9001:2015 ✔ IPC-CC-830 ✔ USP Class VI (Medical) ✔ NASA Outgassing Compliant

Frequently Asked Questions (FAQs)

1. What is Parylene conformal coating?

Parylene conformal coating is a transparent, vacuum-deposited polymer film that provides ultra-thin (5-25µm), pinhole-free protection for printed circuit boards and electronic assemblies. Unlike liquid coatings, Parylene does not require solvents or curing ovens; the CVD process creates a perfectly conformal layer that covers sharp edges, under components, and into deep crevices.

2. How does Parylene coating differ from acrylic, silicone, or urethane?

Parylene coating PCB offers several distinct advantages: it is pinhole-free at ultra-thin thicknesses, chemically inert, biocompatible (USP Class VI), and has superior dielectric strength. However, it is more expensive and cannot be selectively applied without masking. Liquid coatings (acrylic, silicone, urethane) are lower cost and easier to rework, but they are thicker and may have pinholes or uneven coverage.

3. What are the different Parylene types, and which one should I choose?

The four common Parylene for electronics types are: Parylene N (highest dielectric strength, best penetration for MEMS); Parylene C (best overall barrier and chemical resistance, most common for PCBs); Parylene D (higher thermal stability); Parylene HT (excellent thermal and UV resistance, up to 450°C). Our engineers can recommend the best type for your operating environment.

4. Is Parylene conformal coating biocompatible?

Yes. Parylene conformal coating — specifically Parylene N, C, and D — is USP Class VI certified and complies with ISO 10993 for medical device biocompatibility. It is widely used for implantable devices, surgical instruments, and other medical electronics that contact human tissue or fluids.

5. Can Parylene be applied to flexible PCBs or fragile components?

Absolutely. The CVD process occurs at room temperature, so there is no thermal stress on sensitive components or flexible substrates. Parylene PCBA is ideal for flex circuits, rigid-flex boards, MEMS sensors, and assemblies with delicate wire bonds or components.

6. Can Parylene be removed for rework or repair?

Yes, but removal is more difficult than with liquid coatings. Parylene coating PCB can be removed by mechanical abrasion (microblasting), laser ablation, or plasma etching. For field repairs, localized removal by scalpel or polishing is possible. When rework is anticipated, we recommend selective masking of critical areas before deposition.

7. What thickness should Parylene conformal coating be?

Typical thickness for Parylene conformal coating ranges from 5 to 25 microns (0.2 to 1.0 mil). For most PCB protection (moisture, contamination, dielectric isolation), 12-15 microns is sufficient. Thicker coatings (up to 50 microns) are used for additional mechanical protection or extremely harsh environments. Our process control ensures ±10% thickness uniformity across the entire batch.

8. What quality standards do you follow for Parylene coating?

Our Parylene PCBA process complies with IPC-CC-830, MIL-I-46058C, and UL 746E. For medical devices, we support ISO 13485 and FDA requirements. For aerospace, we meet NASA low-outgassing specifications (ASTM E595) and can provide full material certifications and process documentation.

9. What is the lead time for Parylene conformal coating?

Lead time depends on batch size and Parylene type. For prototype quantities (up to 50 boards), typical turnaround is 5-7 business days after receipt of materials. Production volumes are scheduled based on your requirements. Expedited service is available for urgent projects — please contact us to discuss.

10. How do I get a quote for Parylene coating for my PCB?

To receive a quote for Parylene for electronics, please upload your Gerber files, assembly drawings, or sample boards (or detailed photos). Indicate which Parylene type you prefer (or describe your operating environment, and we will recommend), specify any keep-out areas requiring masking, and state your target thickness. Our engineering team will review and provide a detailed quotation within 24 hours.