What are the methods for PCB waterproofing? What are their advantages and disadvantages?

PCB waterproofing is a method of protecting PCBs from water and other liquid damage, by preventing moisture from entering the inside of the circuit board, thereby protecting electronic components from water damage. This can be achieved through coating, packaging, waterproof connectors and other methods to ensure that the circuit board can operate normally in a humid or watery environment and improve the reliability and durability of the equipment.

Importance of PCB waterproofing

01
Preventing erosion damage
PCBs are vulnerable to water and moisture in outdoor, automotive and medical applications, so preventing permanent corrosion damage is one of the main goals of PCB waterproofing. Moisture and water vapor entering the PCB can cause oxidation reactions, resulting in corrosion of copper foil, degradation of solder joints and tarnishing of components.

02
Avoiding short circuits
The ingress of moisture can cause short circuits between adjacent copper traces and close components. Such short circuits can cause erratic device behavior, sparks and excessive current consumption, which can immediately damage the circuit.

03
Dust prevention
Dust and debris accumulation on PCBs can interfere with circuit operation over time. The sealed waterproof coating forms a sealed surface that prevents fine particles from depositing on the circuit board and components. Reliability is further improved over a long service life by being waterproof and dustproof.

04
Extended service life
The service life of electronic components can be extended by thoroughly preventing moisture intrusion and reducing damage caused by corrosion and loosening. Waterproofing not only avoids corrosion and damage to solder joints caused by oxidation of electronic components, but also reduces the repair and replacement costs caused by them.

05
Easy to Clean
Cleaning dirt and contamination from devices becomes much simpler, as the water-repellent treatment allows the PCB to withstand immersion. Sealed electronic devices do not need to be carefully avoided from contact with water, and any accumulated dirt or organic buildup can be quickly washed away by simply rinsing or immersing in water. For products such as medical devices that must be sterilized occasionally, this reduces maintenance time and complexity.

PCB waterproofing method

01
Coating technology
Coating technology is a commonly used PCB waterproofing method, which prevents moisture from entering the inside of the circuit board by applying a layer of waterproof coating on the surface of the PCB.

Application steps of coating technology:

1. Surface preparation: Before applying the waterproof coating, the PCB surface needs to be cleaned and treated to ensure that the coating can be firmly attached to the PCB surface.

2. Apply waterproof coating: Select appropriate waterproof coatings, such as polyurethane, fluorocarbon, etc., and form a protective film on the PCB surface by spraying, brushing or dipping.

3. Curing: The waterproof coating applied on the surface of the PCB is cured to ensure that the coating has sufficient durability and waterproof performance.

Advantages of coating technology:

Coating technology is simple and easy to operate, and the cost is low.

It can be applied to various types of PCBs, including complex multi-layer PCBs.

The coating can provide good waterproof performance and effectively prevent moisture from entering the inside of the PCB.

Disadvantages of coating technology:

The coating thickness is not easy to control, which may affect the size and weight of the PCB.

Coating technology may affect the fine structure and electrical properties on the PCB.

The coating may age and peel off after long-term use, and requires regular inspection and maintenance.

02
Packaging technology
Packaging technology is to protect the circuit board by encapsulating the electronic components on the PCB in waterproof materials to prevent moisture from entering the components.

Application steps of packaging technology:

1. Electronic component packaging: Encapsulate the electronic components on the PCB in waterproof materials, such as epoxy resin, silicone, etc.

2. Encapsulation sealing: Ensure that the encapsulation material can completely cover the electronic components and tightly seal with the PCB surface to prevent moisture from entering the components.

3. Curing: After the encapsulation material is cured, a protective film is formed to effectively prevent moisture from entering the electronic components.

Advantages of packaging technology:

Packaging technology can completely encapsulate the electronic components on the PCB in waterproof materials, providing more comprehensive waterproof protection.

The cured layer of the encapsulation material has good water resistance and chemical corrosion resistance, which can effectively prevent moisture and chemicals from eroding the electronic components.

Packaging technology can effectively protect the electronic components on the PCB from mechanical shock and vibration.

Disadvantages of packaging technology:

The manufacturing process of packaging technology is relatively complex and the cost is relatively high.

The curing process of the encapsulation material takes a certain amount of time, which may affect the production cycle.

Packaging technology may affect the fine structure and electrical performance on the PCB.

Application scope of packaging technology:

Packaging technology is widely used in electronic equipment with high requirements for waterproof performance, especially in outdoor, automotive and medical fields, such as automotive electronic modules, outdoor wireless communication equipment, medical monitoring equipment, etc.

03
Waterproof connector
The waterproof connector adopts a special sealing structure and waterproof materials, which can effectively prevent moisture from entering the connection parts of electronic equipment, thereby protecting the circuit board and connector from water damage.

Principle of waterproof connector:

1. Sealing structure: The waterproof connector adopts a special sealing structure, such as rubber sealing ring, waterproof glue, etc., which can effectively prevent moisture from entering the interior of the electronic equipment from the connection part.

2. Waterproof material: The connection part of the waterproof connector is usually made of waterproof materials, such as waterproof plastic, silicone, etc., which has good waterproof performance and chemical corrosion resistance.

3. Waterproof technology: The waterproof connector adopts special process technology, such as injection molding, compression molding, etc., to ensure that the connection part can be completely sealed to prevent moisture from entering.

Function of waterproof connector:

1. Waterproof protection: The waterproof connector can effectively prevent moisture from entering the interior of the electronic equipment from the connection part, protect the circuit board and connector from water erosion, and ensure the normal operation of the equipment.

2. Dustproof protection: Waterproof connectors usually also have dustproof function, which can effectively prevent dust and debris from entering the connection part and protect electronic equipment from dust and debris.

3. Improve reliability: Waterproof connectors can improve the reliability and durability of electronic equipment, reduce failures and damage caused by moisture entering the connection parts, and extend the service life of the equipment.

Different types of waterproof connectors:

1. Sealed waterproof connector:

Principle: Sealed waterproof connectors use special sealing structures and waterproof materials, such as rubber sealing rings, waterproof glue, etc., which can effectively prevent moisture from entering the interior of electronic equipment from the connection parts.

Application: Sealed waterproof connectors are suitable for applications with high requirements for waterproof performance, such as outdoor electronic equipment, automotive electronics, etc.

2. Magnetic waterproof connector:

Principle: Magnetic waterproof connectors use magnetic suction structure, and the connection parts of the connector are adsorbed by magnetic force to form a sealed waterproof effect.

Application: Magnetic waterproof connectors are suitable for occasions that require frequent disassembly and connection, such as outdoor sports equipment, handheld devices, etc.

3. Threaded waterproof connector:

Principle: Threaded waterproof connectors use threaded structure, and the connection parts of the connector are rotated to form a sealed waterproof effect.

Application: Threaded waterproof connectors are suitable for applications with high requirements for waterproof performance and mechanical strength, such as aerospace equipment, marine engineering equipment, etc.

Shijiazhuang Linke Electronics Tech Co.,Ltd,we are a professional factory for PCB manufacture and PCB Assembly services.For more details,please contact me.
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