There are many fields of PCB applications. Some circuit design solutions need to be considered for waterproofing, especially when they are produced in large quantities, generation costs, environmental protection issues, process capabilities, etc. need to be considered.
The waterproof and moisture-proof protection of PCBA circuit boards are very important. The relatively fragile part in electronic products is PCBA. Once water vapor or corrosive fluid penetrates into the PCBA, it will cause short circuit or corrosion of component pins, which will affect or even damage the function of electronic products.
AiPCBA is a PCB and PCBA manufacturer that can provide one-stop PCB production services, aiming to create a PCB manufacturer with outstanding quality and cost-effectiveness. AiPCBA relies on its 7 years of experience in the electronic processing industry to strictly control the management of circuit board factories, optimize process capabilities, and improve internal and external sales and service levels. We stand out in the competition of PCB manufacturers and support through-hole PCB (Through-Hole PCB), flexible circuit board (FPC), etc. The PCB manufacturing quality and delivery time have won the trust of many customers at home and abroad in the market. Learn more about AiPCBA’s Turnkey PCB Assembly.
The common waterproof methods of PCB are: structural waterproof method, potting waterproof method, surface coating waterproof method.
Structural waterproofing
Compared with a waterproof display, open the mold to make a plastic shell, put the circuit board into the box and then seal the plastic shell, which is to start from the outside to block the water, so as to achieve the purpose of waterproofing.
Mainly adopt the shell for waterproof: classified snap type, screw fixed type, etc., generally fixed or sealed or hot melted, there is almost no room for repair.
The cost of waterproofing is also relatively high. For some small businesses, if the order volume is small, it is not cost-effective to open a mold.
Theoretically, a waterproof shell should be made just like a submarine.
Unfortunately, even though many structural changes have been made, it still cannot better prevent the infiltration of moisture. The circuit board is used in an environment with heavy water vapor. The appearance itself also has the risk of deformation during use. The gap will also be deformed, or the artificial and non-artificial destruction of the appearance will always exist and become a potential worry.
Advantages: good waterproof effect
Disadvantages: The process is difficult to guarantee, the structure has the risk of deformation, and the cost is higher.
Potting waterproof method (sealing waterproof method)
Due to the good thermal conductivity of the potting compound, it is helpful for the heat dissipation of the power circuit board after potting, but the EMI will become larger after the circuit board potting.
Advantages: good waterproof effect
Disadvantages: high cost, too difficult to repair
Surface coating waterproof method
1.Three anti-paint
Three anti-paint is also called circuit board protective oil, coating oil, waterproof glue, insulating paint, moisture-proof paint. The three-proof paint products are generally thick. Basically, the coating thickness will reach 50 microns, the heat dissipation is not good, and the viscosity is high. The output of one kilogram is relatively low, drying is slow, and even takes an hour or two to dry. The three anti-paint is a layer of adhesive film that is cured on the PCB of the electronic product, which is used for the circuit board to prevent moisture, corrosion, and salt fog. However, this layer of film can only protect against moisture and a small amount of moisture. If the electronic product is completely immersed in water, it will fail. Because of its own process, the three anti-paint is not resistant to falling and vibration. It is easy to peel off due to external force. The protective effect of the PCB board is very limited, it is difficult to see whether it is evenly coated by direct observation with the naked eye. At present, many three-proof paints still use volatile solvents, which is very harmful to the human body and the environment. For manufacturers that need to export products, environmental protection cannot meet the standards.Advantages: low cost
Disadvantages: poor waterproof effect, not environmentally friendly.
2.Parylene Nano Waterproof and Moistureproof Coating
Parylene coating, its performance can meet the coating needs of circuit components. These transparent polymers are actually highly crystalline and linear, have excellent dielectric and barrier properties, Parylene coating technology, and are chemically inert, and dense.
The thin leads of integrated circuit silicon wafers coated with Parylene can be reinforced by 5-10 times, and Parylene can also penetrate under the silicon wafer to improve the bonding strength of the silicon wafer and improve the reliability of the integrated circuit.
Coating protection for printed circuit boards and hybrid circuits is one of the most popular applications of Parylene. It meets the XY type indicators in the US military standard Mil-I-46058C and meets the IPC-CC-830B protection standard. The high reliability of the circuit board can still be maintained in salt spray tests and other harsh environments, and the function of the resistors, thermocouples, and other components on the circuit board will not be affected.
The thickness of the Parylene coating is thin (usually 25um), which has little effect on the surface insulation resistance of the circuit board, and is also very beneficial to the heat dissipation generated by the components during operation. In addition, due to the good symmetry of the molecular structure, it still has a small dielectric loss and dielectric constant at higher frequencies. Its high frequency and low loss characteristics make it reliable protection for high-frequency microwave circuits. condition.
Advantages: The waterproof effect is very high, and the protective film layer has no dead angle in 360 degrees; it can also effectively prevent moisture, mildew (zero grade), anti-corrosion, and anti-salt spray;
Disadvantages: None
PCB Manufacturing and PCB Assembly in AiPCBA
AiPCBA has over 7 years of knowledge and combined experience in rendering high tech PCB assembly service, PCB manufacturing service and different PCB assembly technologies like Through-hole (THT) and Surface Mount (SMT). Mainly, we work with three types of printed circuit boards including Rigid PCB, Flexible PCB and metal core PCB.
We have customers from different industries in terms of cost-effectiveness, quality, delivery and any other requirements. From PCB layout to PCB prototyping, mass manufacturing, and then PCB assembly, electronic box assembly services, our printed circuit boards are widely used in robotics, medical, automotive, communications, industrial and consumer electronics products.
All PCBs in AiPCBA are produced based on UL and ISO certification standards. All our normal specification PCBs are strictly obeying to IPC-A-6011/6012 Class 2 latest version and IPC-A-600 Class 2 latest version.
Learn more about AiPCBA’s Turnkey PCB Assembly.