In order to meet the higher usage requirements in daily life, users have higher and higher requirements on the waterproof function of electronic products. The waterproof PCB plays a very important role in the waterproof function of electronic products. There are two main methods for waterproofing using waterproof circuit boards. Species: potting waterproof and surface coating waterproof. The main recommended method for surface coating waterproof is PCB nano coating.
The circuit board nano waterproof coating is a new nano material, also called nano coating, which is currently an ideal substitute for three anti-paints. Its thickness is only 2-4 microns, which is invisible to the naked eye. An extremely thin mesh is formed on the surface of the PCB, which effectively reduces the surface energy of the PCB, forms a lotus leaf effect, has good heat dissipation performance, does not affect the normal conductivity of the connector, and can be waterproof IPx5, basically meets the waterproof standards of life, can also be corrosion-resistant, acid and alkali resistant.
The construction process of the nano waterproofing agent is spraying or dipping, which is easier to form at one time, the coating is uniform, the sag is less, and the phenomenon of bubbles and peeling is not generated. The component pins and the narrow gaps are completely covered, and The traditional three-proof material process is prone to air bubbles and unevenness, and there are many cases of repeated spraying in certain parts. Some plates need to be washed and dried before spraying. Uber Nano Waterproofing Agent avoids these situations. The product can be widely used in communication equipment, circuit boards and other fields.
Nano water-proof and anti-corrosion materials for electronic products on the market are generally divided into the following three types, each with advantages and disadvantages. Here is a brief summary of the performance of several waterproof coatings:
1) Surface spray type nano waterproof coating
In the form of surface spray, a layer of nano film is formed on the surface of the mobile phone or tablet computer, thereby preventing the entry of moisture from the outside and achieving a waterproof effect. It can be used on some products that need waterproof function for a short time with simple operation. But the anti-wear ability is weak. After all, the coating is on the shell part of the product. The shell is the most intimate part of various items. In the face of too many complicated use environments, the damage rate will be greatly accelerated, and the product is in use. There is a risk of deformation of the mid-appearance. Once deformed, there is no guarantee of the effect of moisture on the internal circuit board.
2) Vacuum spray type waterproof coating of coating machine
This technology uses a vacuum coating machine to spray the waterproof agent into the interior of the product from the gap in the appearance of the product in the form of a spray under vacuum conditions. The purpose is to let the waterproof agent contact the circuit part more widely. However, due to the different appearance and structure of various products and the inconsistency of sealing, the coating formed by the waterproof agent inside the product after spraying is often incomplete. There must be better equipment and good waterproofing agent.
Multiple devices can be operated at the same time, speeding up efficiency. However, it needs to purchase a certain number of equipment, first of all, the quality of the equipment will affect the quality of the coating, and some of the equipment's publicity effect is much greater than the actual application effect, so it will be largely affected by the performance of the equipment, according to its principles, Different mobile phones and different degrees of sealing will have different responses to the spray effect inside the product, which is easy to cause incomplete coating and poor yield.
3) PCBA immersion nano coating
This technology is the current trend, which is to add a process to the production line after the placement of all components on the PCB is completed, that is, the circuit board is directly immersed in the nano waterproof liquid, the immersion time is only 3-5 seconds, and the natural temperature is normal after removal The shell can be installed after being left to dry for about 10 minutes, which is very convenient. There is no need to purchase equipment such as a coating machine, and the conjunctiva is also complete.
With simple operation, no need to increase equipment investment and no vacuum environment, even coating, only need to soak PCBA in nano waterproof liquid for a few seconds. After finishing the coating, it does not affect the conductivity of the connector. It can be acid-proof Alkaline salt corrosion, because it is directly coated on the PCB board, the deformation and damage of the product appearance will not have a significant impact on the PCB. Because it is based on PCBA immersion coating, it is suitable for almost all electronic products. But at present, it is not possible to rely on PCB nano-coating to achieve waterproofing of level 7 or above, only for life waterproofing.
Regardless of how the nano-coating is applied, the core is the nano-water-repellent liquid. The technical content of the nano-water-repellent liquid will directly determine the performance and quality of the nano-coating. Therefore, choose a nano with reliable quality, good reputation, and stable performance after testing. Waterproof coatings are issues that should be considered by the majority of electronics manufacturers.