Role of Conformal Coating in Pcb Board Assembly Manufacturing
Conformal coating is widely recognised as a key component for protecting printed circuit boards (PCBs) from damage and failure in practical environments that embrace corrosive chemicals, vibration, high dust levels, salt fog, extreme temperatures and moisture. It’s a process that should be standardised for all products used in the military, aerospace, automotive and automation industries but is now being used more frequently by companies producing consumer goods such as electrical devices and household appliances.
The process of applying a conformal coating to a pcb board assembly manufacturing involves dipping the board into an epoxy-like resin. This is usually done using a spray can or automated equipment which allows for accurate and even coverage of the entire surface area. The resulting coating, which is typically transparent, is an excellent barrier to harsh environmental conditions, helping the board to retain its integrity and extending the lifespan of the product.
It’s important that the board be thoroughly cleaned before this process begins. If it is not, the debris can interfere with the adhesion of the coating, resulting in corrosion or short circuits. This is particularly problematic in medical equipment, where strict hygiene standards are required.
Almost all material suppliers recommend that the board be pre-washed before coating. If this is not possible due to cost or time considerations, qualification procedures can be carried out to reduce the likelihood of a coating defect occurring during production. In particular, ion chromatography tests can be undertaken to check for cleanliness before a conformal coating is applied.
Explain the Role of Conformal Coating in Pcb Board Assembly Manufacturing
Aside from offering an effective shield against harsh environments, conformal coating can also be used to protect sensitive components on a circuit board. In these instances, it’s important that the manufacturer takes care to apply a coating with enough thickness. Too little protection may result in heat entrapment and other problems, while too much can add weight and make the boards too large for the intended application.
Most conformal coatings are available in a wide range of colours, helping the manufacturing team match the right color to the specific application. Some are available in opaque shades to help protect markings and labels on the surface of the board. This feature is also useful when the PCB needs to be labelled for post-production inspection and quality control purposes.
There are a number of different types of conformal coatings currently on the market, and each one has its own advantages and disadvantages. The most popular option is polyimide, which has good mechanical properties, provides resistance to moisture, solvents and excessive temperatures, and is easy to clean.
Another popular choice is parylene, which offers superior dielectric strength and transparency, but requires specialized vapor phase deposition equipment to apply it on the board. Both are effective in their respective fields, but it is important to decide which one best suits the requirements of your application before committing to a purchase. Ultimately, the decision comes down to a combination of factors including your budget, technical specifications and the PCB quality standards that you are aiming to meet.
