Selecting a Parylene Conformal Coating Service Provider

Selecting the right material and application technique for your coating project can prolong the lifespan of your assembly and boost its efficiency. While various liquid resin coatings such as acrylic, epoxy, silicone, and urethane exist, Parylene stands out for its outstanding conformal coating capabilities. Nevertheless, it is renowned for its complexity and elevated cost.

Unlike liquid coatings – which are generally brushed, dipped (immersed) or sprayed onto substrates – Parylene uses a chemical vapor deposition (CVD) application process. CVD converts powdered Parylene dimer into a vapor, on a molecule-by-molecule basis. Enacted in a vacuum, the gaseous Parylene seeps deeply into a substrate’s most minute surface crevices. The result is a uniform, pinhole-free coating, offering unsurpassed assembly protection.

While Parylene conformal film is effective, the CVD method presents notable drawbacks that need consideration, including:

• Greater expense than most liquid technologies
• Small batch-size/greater turn-around time
• Difficulty reworking/repairing coatings

These conditions highlight the importance of choosing a Parylene provider that can meet your process and specific product needs.

Project Experience

Seek a coating service provider with diverse experiences in not only Parylene but all conformal coatings. Evaluating a companies with diversified coating experience increases the likelihood of receiving a customized solution. Selecting a vendor solely focused on Parylene might result in misaligned interests.

Look for companies with experienced staff and proven processes, capable of accommodating assignments ranging from small custom orders to full production runs. Quick project completion is sought after, as long as quality assurance (QA) can be upheld. This is especially crucial for rush orders; make sure the company you select can fulfill the accelerated task within quality assurance standards that align with your project requirements, irrespective of complexity and volume.

QA Certifications

QA certifications hold equal significance in Parylene application and liquid coatings. When choosing a conformal coating service provider, customers should opt for companies verified by the industry for their dedication to upholding QA standards in conformally coated processes and products. QA certifications present achievable and necessary performance benchmarks, stipulating appropriate QMS for Parylene application. In addition to ISO9001 and NASA-STD-8739.1, important certs for Parylene are:

• Both AS9100C and IPC 001:2015 specify QMS guidelines for aviation, space and defense applications, focusing on ongoing systemic improvement, customer support, and compliance with applicable regulatory/statutory requirements.
• IPC’s Class 3 Standard for Coating Requirements provides guidelines for maintaining reliable performance under challenging operational conditions.
• IPC-7711/7721 delineates rework/repair benchmarks for Parylene/liquid coatings.
  Coating thickness requirements are set by IPC-A-610, according to the coating material/assembly function.
• IPC-CC-830/830B delineates optimal-confidence criteria/ minimum test-redundancy for Parylene/liquid coatings; 830B standardizes coating performance for military-grade/ruggedized performance conditions.
• ITAR regulations safeguard your sensitive company/process/ product data.
• NADCAP AC7120 Rev A provides QMS guidelines for audit criteria/circuit card assemblies for aerospace applications.
• RoHS assures Parylene dimer/process materials are compliant with European Directive 2002/95/EC.
• USP biological testing requirements for Class VI Plastics assure Parylene used for biomedical devices is safe.

When searching for Parylene services, opt for companies with key QA certifications. These certifications signify the their commitment to professional QA standards, ensuring industry compliance, performance and risk management.

Coatings Application

Parylene comes in various types, with notable variants like C, N, F, D, AF-4 and Parylene HT®. Each type provides unique chemical, electrical and physical properties, offering a range of distinct applications.

Parylene C and N exhibit superior substrate adhesion and robust resistance to chemical corrosion compared to other Parylene variants. They offer greater versatility for a diverse range of applications and show minimal trace metal contamination. While N represents the most basic form chemically among the Parylenes, C finds widespread use as a coating for products and components. The deposition rates of the remaining Parylenes are slower and more expensive than C and N, which are the preferred choices for the majority of current Parylene applications.

Type F Parylene stands out among its counterparts due to its lower coating capacitance, operational electrical charge and dielectric constant. Its superior thermal stability makes it an ideal choice for inner layer dielectric (ILD) applications and ultra-large-scale integration (ULSI), accommodating over a million circuit elements on a single chip. These conditions improve F’s utility for MEMS/nanotechnologies applications.

Parylene D provides effective coating protection at 134°C (273°F), and reliable component protection for 10 years at 100° C, in oxygen-dominated environs.

More costly/lower yield Parylene HT and type AF-4 exhibit enhanced UV stability and higher oxidative resistance, suitable for specialized applications.

For dependable Parylene application services, choose a provider that is:

• Proficient with conformal coatings of all types
• Competitively-priced and provides consistent quality services
• Focused on meeting and surpassing QA specificaitons
• Able to provide thoroughly-documented production and inspection processes

Backed by over 50 years of experience, a proficient team of coating specialists, top-notch materials, and tailored process solutions, SCS is poised to meet your conformal coating requirements. Contact us to learn more.