Top Electronic Coating Solutions for Modern Devices

Electronic coating protects electronic components from moisture, dust and chemicals, so they last and perform.

This article covers the different types of coatings, application methods and their uses in industries like automotive and aerospace.

Summary

• Electronic coatings protect components from the environment, across industries like automotive and aerospace.
• There are many types of electronic coatings, acrylics, epoxies and Parylene, each for specific applications and conditions.
• Choosing the right application method and curing process is key to getting the best coating performance and component life.

What is Electronic Coating

Electronic coating protects components from the environment, moisture, dust and chemicals. In consumer electronics conformal coatings protect devices like smartphones and tablets from harsh conditions. These coatings form a thin layer over the electronic circuitry, increasing dielectric resistance and corrosion protection.

Choosing the right electronic coating is key. Consider the operating environment and application requirements. For example conformal coatings are essential in consumer electronics to prevent moisture ingress and dust accumulation, so the device lasts longer. Knowing the many applications and benefits of these coatings helps you make informed decisions to extend device life and performance.

Types of Electronic Coatings

One size does not fit all for electronic coatings. There are many types of conformal coatings, each for specific applications and conditions. The most common are acrylics, epoxies, silicones, urethanes and Parylene. Each has its own properties that determine its use.

Acrylic coatings are popular for ease of application and removal. They have good dielectric properties and are relatively cheap. Silicone coatings have high temperature stability and flexibility, for applications with thermal cycling. Urethanes are abrasion and chemical resistant, epoxies are for strong adhesion and mechanical strength.

Parylene coatings are special for their application process and protection properties. Applied by vapor phase deposition Parylene coatings provide a very thin but robust layer of protection against moisture and chemicals. These coatings are ideal for applications where high protection in a small form factor is required.

Choose the right conformal coating by considering protection needs, application method and reworkability.

Application Methods for Electronic Coatings

Uniform application of electronic coatings is key for full coverage, especially for complex geometries. Different methods suit different production volumes and precision requirements. The main application methods are spray coating, dipping and selective coating.

Spray coating, used for medium volume production, uses tools like spray aerosols or spray guns. Dipping is for high volume applications if the printed circuit boards are designed to avoid thin tip coverage.

Selective coating methods, used for intricate and high precision applications, use advanced technologies like needle and atomized spray applicators. Each method has its advantages and challenges so the choice of application method depends on the project requirements.

Spray Coating Techniques

Spray coating is efficient and flexible. The process involves using spray aerosols or spray guns to apply conformal coatings. This method is good in spray booths for medium volume production, for uniform application over components. But spray coating has limited penetration in 3D structures so masking can be complicated and some areas may not be coated.

Despite the challenges spray coating is preferred for ease of use and flexibility. Choice between spray aerosol and spray gun depends on volume of operation and project requirements. Proper technique and equipment in spray coating can produce high quality finish and good protection for the devices.

Dipping Process

Dipping process is for high volume processing applications, good for large scale production environments. In this method components are submerged in liquid coating material, full coverage is ensured. A common issue is thin tip coverage where some areas are not coated due to PCB design.

Double dipping or using multiple thin layers of atomised spraying can solve this problem. Applying vacuum during submersion in the coating resin can also improve the dip or dam-and-fill coating. These adjustments will give more uniform coating distribution and better protection for the components.

Selective Coating Methods

Selective coating methods are precise and efficient, especially for detailed coverage. Technologies like needle and atomised spray applicators, non-atomised spray and ultrasonic valve technology give precision in the coating process. Programming flow rates and material viscosity in the computer system controls coating thickness for consistent results.

A challenge in selective coating is the capillary effect around low profile connectors which causes unintended absorption of the coating. Double dipping or multiple thin spray layers can solve this. These methods will give adequate protection to intricate components without compromising the coating.

Measuring Coating Thickness

Measuring coating thickness is for product quality, process control and cost management. Coating thickness is measured in two categories. These are wet film and dry film. Wet film thickness can be measured using gauges that can measure coatings immediately after application. This method gives immediate feedback so adjustments can be made during the process to ensure uniform coverage.

For dry film thickness non-destructive methods like magnetic, eddy current and ultrasonic are commonly used. These methods give accurate measurement without damaging the components. The choice of measurement method depends on the coating type, substrate and required accuracy level. Destructive methods like cross-sectioning and gravimetric measurement are used for precise measurement but time consuming and reserved for critical applications.

In selective coating systems, adjusting flow rates and material viscosity controls the coating thickness. This ensures consistent application and helps in maintaining the desired properties of the coating. Measurement and control of thickness is critical for optimal performance and durability of the devices.

Curing Processes for Electronic Coatings

Curing processes determines the durability and performance of electronic coatings. UV conformal coatings are used in automotive and consumer electronics for its fast curing time and thermal cycling resistance. Moisture curing is a reactive process to moisture, polymerizing with exposure and takes up to few days to cure.

Heat curing is used for solvent based acrylics when speed is critical, while air drying is for standard solvent based acrylic coatings. Each curing mechanism affects the application method and can introduce complexity and errors in uncontrolled process. Understanding these processes is key in selecting the right curing method for specific coating and application requirement.

The curing process affects the durability and performance of electronic coatings. Proper curing will make the coating reach its full protective capabilities, giving long term protection against moisture, dust and chemicals. Selecting the right curing method will give reliability and lifespan to the electronic devices.

Removal Methods for Electronic Coatings

Removing electronic coatings is challenging due to its chemical properties. Urethane resin coatings are hard to remove once cured due to its high chemical resistance and abrasion properties. Epoxy conformal coatings has hard finish and humidity resistance, making it difficult to remove without damaging the components.

Common methods to remove coatings are using a soldering iron to burn through the coating in isolated areas. Coating removers especially in pen packaging can also be effective.

Removing conformal coatings is necessary when replacing damaged components or rework. Knowing the specific removal method for each coating is critical to maintain component integrity during rework or repair.

Regulatory Standards and Certifications

Compliance to regulatory standards and certifications ensures the reliability and safety of electronic coatings. The major certifications for electronic coatings are IPC-CC-830B and UL746E. IPC-CC-830B includes tests for moisture resistance and thermal shock to ensure the coatings can withstand harsh environment.

UL746E certification involves testing for electrical safety and flammability of coated electronics. Retesting is required annually to maintain UL746E registration and ensure continuous compliance and performance.

Both IPC-CC-830B and UL746E uses UL94 standard to test flammability, V-0 means minimal flammability risk. Compliance to these standards ensures the performance and safety of electronic coatings.

Environmental Factors

Environmental factors affects the selection and performance of electronic coatings. E-coating prevents corrosion and moisture damage in devices. Environmental exposure, humidity and wide temperature range affects the performance and selection of coatings.

Products that undergo UV curing has better chemical resistance and performs well in harsh environment. UV curing gives electronics physical properties such as increased hardness to resist scratches and mechanical wear.

UV curing technology improves the durability of coatings by solidifying the material fast, resisting stressors. Uniform application during UV curing minimises defects and contributes to the overall strength and reliability of the coating.

Industry Applications of Electronic Coatings

Electronic coatings is used in automotive, aerospace and consumer electronics.

In automotive, these coatings protect electronic control units and other components from extreme temperature and vibration. Aerospace uses conformal coatings to maintain the reliability of avionics system under harsh condition.

Consumer electronics gets the benefits of these coatings by making devices like smartphones functional even in moisture and dust exposure. Nano-coatings in medical devices protects electronics from contaminants, ensures biocompatibility and utilises protective materials effectively.

In industrial setting, nano-coatings improves the reliability of control systems and sensors in harsh environment. Selective coating technology provides repeatable coverage on complex shapes, meets moderate to high volume requirements. These various applications shows the versatility and importance of electronic coatings in today’s technology.

Choose the Right Coating for You

Choosing the right conformal coating for your needs requires careful thought of several factors. The level of protection and application method are the key to this decision. For example if you need a coating that has strong dielectric properties and easy to remove, acrylic resin conformal coating might be the best. But if the application requires high temperature stability and flexibility, silicone resin coating might be more suitable.

You need to match the coating’s properties to the environmental conditions and operational stresses the electronic components will be exposed to. For example urethane coating is highly resistant to abrasion and chemical exposure so it’s ideal for harsh environment.

On the other hand Parylene coating with vapour phase deposition process provides thin film yet robust protective layer against moisture and chemicals, perfect for application that requires minimal form factor. By understanding these details you can choose the right coating for your needs and get the best performance and longevity of your electronic devices.

Conclusion

In summary, electronic coatings is a must in protecting sensitive electronic components from environmental factors to extend their life and performance. From understanding the types of coatings such as acrylics, epoxies, silicones, urethanes and Parylene to exploring the application method such as spray coating, dipping and selective coating we have covered the basics of coating process. Measuring coating thickness and proper curing is crucial to the durability and efficiency of the coating.

Choose the right coating by considering the protection needs and application method so your electronics are protected from moisture, dust and chemical exposure. Following regulatory standards and certifications like IPC-CC-830B and UL746E ensures the reliability and safety of the coating. By making informed decisions you can increase the durability and functionality of your electronic devices and they will perform well in any environment.

FAQs

What is conformal coatings and why?

Conformal coatings is a protective layer that shields electronic components from environmental factors like humidity, dust and corrosion to increase their reliability and life. Application is critical to the performance and durability of electronic devices.

What are the types of electronic coatings and how are they different?

The different types of electronic coatings—acrylics, epoxies, silicones, urethanes and Parylene has different properties like temperature stability, flexibility and resistance to chemicals and abrasion. Choosing the right coating depends on your application requirements.

How are electronic coatings applied and what are the methods?

Electronic coatings are applied through methods such as spray coating, dipping and selective coating. Choose the method that suits your project requirements for best results.

Why is coating thickness measurement important and what are the methods?

Measuring coating thickness is crucial for product quality and cost control. Common methods used are wet film gauges for immediate feedback and non-destructive methods such as magnetic, eddy current and ultrasonic for dry film thickness measurement.

What to consider when choosing the right coating for your devices?

When choosing the right coating for your devices consider the level of protection required, application method and environmental conditions. Also consider properties like dielectric strength, temperature stability and chemical resistance.