Coating Enhances PCB Assembly
Conformal coating enhances a printed circuit board’s ability to function as intended while minimizing heat entrapment, excess weight, and other issues. It also allows for the use of smaller components, which helps reduce cost and the need for housings and enclosures. Choosing the right conformal coating can be difficult, but an experienced electronic contract manufacturer can provide guidance to help ensure the best results for your PCB assembly project.
There are a number of different types of conformal coating materials, each with unique properties that allow them to be used in different environments. These include silicone, polyurethane, and epoxy. Each of these materials has advantages and disadvantages depending on the environment where the pcb circuit board assembly will be operating. The choice of conformal coating will also depend on the application process chosen. There are two main methods for applying conformal coating, namely spraying and dipping. The dipping method is ideal for large production runs as it can apply the coating quickly. The spraying method is better suited for low-volume production and can be used to mask areas of the circuit board that should not be coated.
Once the coating is applied to a circuit board, it must undergo curing, which can take a variety of forms. Some coatings require UV radiation and infrared heat, while others are curable using a combination of light and ventilation. The curing process must be carefully controlled to prevent the coating from delaminate or cracking.
How Conformal Coating Enhances PCB Assembly
During this process, it is important to keep in mind the location and placement of the circuit board components. Tall components may shadow smaller ones during the curing process, while bare surfaces can transmit heat or electricity to adjacent parts. It is also necessary to protect the surface of the circuit board from contamination by foreign substances.
The conformal coating must be properly tested and certified before it is allowed to be used in production. These tests can range from simple visual inspection to more in-depth immersion and corrosive gas testing. For example, a salt mist test can expose the conformal coating to a harsh environment that contains salt and water to check its ability to resist corrosion. Other corrosive tests may include exposing the conformal coating to hydrogen sulphide or sulphur dioxide, which can be very damaging to electronics.
In addition to these tests, it is important that the conformal coating meets regulatory standards set by local and federal authorities. This includes guidelines from the Occupational Safety and Health Administration (OSHA) that focus on worker safety, as well as environmental guidelines from the Environmental Protection Agency (EPA). Depending on the environment in which the circuit board will operate, other certifications may be required. An expert electronic contract manufacturer will be able to advise on the appropriate tests and certifications for your specific project.