Electronic components and exposed conductors are prone to chemical or mechanical degradation over time. To ensure that electronics remain functional and reliable for a long time, manufacturers have developed ways to protect PCBAs from damage. One of these protective measures is to apply a conformal coating, which safeguards PCBAs from chemical damage and extends their lifespan and reliability in multiple ways.
However, there are several materials to choose from when it comes to selecting a conformal coating. Each material has different electrical and chemical properties, and it's crucial to select the appropriate one for your needs. In addition to the conformal coating process, this article will briefly explore the various types of coatings available and their applications in different areas.
PCBA conformal coating is also known as PCBA protective oil, PCBA waterproof glue, PCBA insulating paint, because it has three functions of waterproof, moisture-proof and dustproof for PCBA, so it is called "PCBA three-proof paint". What are the coating methods of PCBA conformal coating?
1. dipping: It is more economical for large equipment, but the thickness after coating will be influenced by the temperature, time, speed of extraction, vertical flow time, whether to add air knife and other factors.
2. Spraying: It is more economical for small and medium-sized equipment. When spraying is used, just like painting, the uniformity of the coating depends on the relative speed of movement, the spray position, the spray pressure, and whether there are higher parts. In addition, the bottom of the part cannot be sprayed and may require additional treatment.
3. Brushing: More economical for small equipment. When coating, it is easy to cause uneven coating due to the skill proficiency of coating, and you should also pay attention to the problem of brush hair loss. The bottom of the part is also more difficult to be coated.
4. Selective Coating: Although coating has many benefits, it often takes much time and labor, and you can also choose to use in the needed areas.
What tools are needed to make PCBA conformal coating? Such as paint box, rubber gloves, mask or gas mask, brush, American adhesive paper, tweezers, ventilation equipment, drying rack, oven. What are the technical requirements for making PCBA conformal coating:
1. Brush conformal paint protection must be made after testing, inspection and thorough cleaning before PCBA assembly.
2. The brush used should be kept clean and forbidden to be used for other operations; When painting, be careful, and not to drip into the parts that do not need to be painted; After use, the brush should be cleaned using thinners.
3. The coating layer should be transparent and evenly cover the PCB board and components, and the color and consistency should be uniform and consistent.
4. The process steps are: brush the A side → surface dry→ brush the B side → curing at room temperature
5. Spraying thickness is 0.1mm-0.3mm
6. All coating operations should be carried out under the condition of not less than 16 ℃ and relative humidity below 75%. PCB as a composite material will absorb moisture, if without dehumidification, conformal paint can not fully play a protective role. Pre-drying, vacuum drying can remove most of the moisture.
It is important for conformal coatings to meet international standards. The main standard for conformal coatings is IPC-CC-830C, which covers every type of conformal coating and addresses specific environmental concerns such as water, fungus, and flammability. The standard also provides guidelines for the appearance and functionality of electronics, as well as for the use of different materials and processes in their manufacture. Other international standards exist for specialized use cases, including electronics assemblies and soldered electronics.
Conformal coatings are typically a mixture of resin and water or solvents, and can be applied in various ways. Conformal coatings that are purely resin-based are semi-permeable, while coatings combined with other substances like epoxy are waterproof and impermeable. Semi-permeable coatings are typically used on electronic components.
Please send Email to firstname.lastname@example.org or call us through +86 13828766801 Or submit your inquiry by online form. Please fill out below form and attach your manufacturing files( PCB Gerber files and BOM List) if need quotation. We will contact you shortly.