Introduction: Ensuring the longevity and reliability of electronic components is a top priority at Burton EMS. Conformal coating is integral to creating PCBs and other electronics that can survive in today’s harsh environments. A guardian against various environmental threats, conformal coating is a key factor in giving the electronics we produce a longer life in the harshest conditions.
Burton Engineer Eric Thier says, “Conformal coating has become more important in an era where electronics are expected to perform in places they had not previously been deployed. The abilities of Burton EMS to provide conformal coating in a cost effective, reliable manner means our client’s products will be able to perform and sustain their function regardless of the demands or environment.”
This article aims to demystify conformal coating, outlining its importance, types, applications, and best practices, solidifying your understanding of this crucial process in the electronics industry.
Understanding Conformal Coating: A Vital Defense for Electronics Conformal coating is a protective non-conductive dielectric layer applied to printed circuit boards (PCBs) and related equipment. This thin polymeric film ‘conforms’ to the contours of the board, providing a shield against moisture, dust, chemicals, and temperature variations. This layer is pivotal in preventing corrosion, short circuits, and other malfunctions, thereby enhancing the durability and performance of the electronic assembly.
Types of Conformal Coatings: Exploring the Options Several types of conformal coatings are used to protect electronic components, each with unique properties suited to different operating environments:
- Acrylic Resin (AR): Known for its ease of application and removal, acrylic resin provides fair protection against moisture and abrasion.
- Silicone Resin (SR): Offering excellent flexibility and protection against high temperatures, silicone resin is ideal for high-stress environments.
- Epoxy Resin (ER): Renowned for its strong chemical resistance and durability, epoxy resin is used in applications requiring robust protection.
- Urethane Resin (UR): Urethane coatings are known for their excellent chemical, abrasion, and humidity resistance.
- Parylene (XY): Parylene provides superior protection and is applied through a unique vapor deposition process.
At Burton we use a Humiseal UV 40 Acrylic Resin product (acrylated polyurethane ). This product provides excellent chemical resistance, surface hardness, flexibility and moisture resistance. The material fluoresces under UV light for quick inspection and cures in a matter of seconds allowing for faster output and lower costs.
The Application Process: Precision and Care The application of conformal coating requires precision and attention to detail. Common methods include brushing, spraying, dipping, and selective robotic coating. The choice of application method depends on various factors, including the type of coating material, the specific requirements of the PCB, and production volume.
Benefits of Conformal Coating: Beyond Protection While the primary function of conformal coating is to protect electronic circuits from harsh environments, its benefits extend further:
- Extended Lifespan: Conformal coating significantly increases the operational life of PCBs.
- Improved Performance: By preventing short-circuiting and electrical leakage, conformal coating ensures optimal performance of electronic assemblies.
- Cost-Efficiency: Protecting PCBs from environmental damage reduces the need for repairs and replacements, leading to long-term cost savings.
Best Practices in Conformal Coating: Ensuring Excellence To maximize the benefits of conformal coating, it is crucial to follow best practices:
- Thorough Surface Preparation: Proper cleaning and preparation of the PCB surface are essential to ensure coating adherence. Our Selective conformal coat line includes an Atmospheric Plasma Treatment System to accomplish this. Plasma cleaning is a process that uses an ionized gas called plasma to remove organic matter from a surface. It works by generating ultraviolet light that breaks the organic bonds of surface contaminants, and by creating oxygen species that react with the contaminants to form water and carbon dioxide.
- Choosing the Right Material: Select the conformal coating material that best suits the operating environment of the PCB.
- Precise Application: Ensure the application method is meticulously executed to avoid voids or excessive coating thickness. At Burton EMS we utilize a no touch Automated Selective Conformal Coating line allowing for both efficiency and repeatability. This system allows for accuracy within 2mm. Additional investments to the line include Jet dispensing technology that allows for atomized spray for more accurate border keepouts and complicated shapes.
- Validation. Ensuring the proper coating thickness and repeatability. In addition to visual inspection Burton EMS utilizes a laser measurement device to ensure each assembly meets customer or IPC standards for thickness. This information is stored for each individual assembly for full tracking, traceability, and containment.
Conclusion Conformal coating is a cornerstone in the protection of electronic components, offering a shield against environmental threats while enhancing performance and longevity. Understanding the types of conformal coatings, their applications, and best practices is essential for anyone involved in the electronics manufacturing industry.
Embrace the Protection of Conformal Coating For those looking to safeguard their electronic components and ensure their durability and efficiency Burton EMS can ensure that your product is properly protected. Our in-house team of conformal coating experts has the latest technology and a host of options to conformal coat your next assembly. Contact Burton EMS today to discuss your needs and learn more about our abilities for your project.
