Differences in Four Types of Heat Dissipation Fan Adhesive Waterproofing IP68 Waterproofing Processes

In the use of heat dissipation fans, vacuum coating and glue injection processes are usually used for waterproofing treatment of the motor parts. The glue injection process can achieve a waterproof level of up to ip68. The waterproof glue injection process can be divided into motor frame with AB glue injection, separate direct use of mold cup with AB glue injection, BMC process with glue injection, and fully automatic low-pressure vacuum injection

1、 Process Description of Heat Dissipation Fan with Frame Gluing

1. Due to the limitations of the molding process, the copper tube is wrapped on a rubber shell, which is difficult to implement on models with a thickness of 8 centimeters. The structural strength of the coated copper tube is relatively low.

2. This glue filling process uses glue at room temperature, and the glue used by each motor manufacturer has different prices and significant differences. This type of adhesive is epoxy resin type, with poor thermal conductivity and high adhesive stress during curing.

3. The disadvantage of the frame gluing process is that the motor of the fan has a shorter lifespan. It is difficult to improve efficiency, the fan speed is limited, and the fan motor temperature increases, making it difficult to remove heat, which can only be conducted through copper pipes.

4. Shortcomings in the glue filling process: This glue filling process makes it difficult to remove air from the glue, resulting in bubbles in the motor inside the glue filling shell, insufficient glue filling in the motor, and a lack of glue.

2、 Explanation of the Glue Filling Process for the Separate Mold Cup of the Cooling Fan

1. After mixing AB glue, pour it into a rubber cup with a motor. The principle of this type of glue pouring is the same as that of frame glue pouring. When pouring glue, the glue should be vacuumed in advance and mixed evenly. If the air is not completely pumped or mixed thoroughly, the motor after pouring glue is prone to bubbles, and poor fluidity of the glue can also cause insufficient glue pouring and not covering the motor, resulting in defects.

2. The AB adhesive material used for this type of sealant has high stress and structural strength after solidification, and is prone to cracking when encountering high and low temperatures.

3. The thermal conductivity of glue is not good, and the temperature rise of the motor after glue injection is more than 10 degrees higher than before, which shortens the service life of the fan

4. Advantages of individual gluing: low gluing cost and fast efficiency

3、 Heat dissipation fan BMC process description

1. BMC injection molding process: It involves using an injection molding machine to inject BMC material into the motor through high-temperature injection molding.

2. Temperature requirements. During processing, BMC is required to maintain low viscosity flow dynamics for a long time at the barrel temperature. The temperature of the material barrel is generally divided into two or three stages for control, with a lower temperature near the hopper end and a higher temperature near the nozzle end. Generally, the difference is 20-60 ℃, and the mold temperature is generally controlled to operate at 135-185 ℃.

3. Injection pressure. Due to the poor fluidity, fast solidification, and complex mold structure of BMC, it is advisable to choose a higher injection pressure, usually between 80 and 160MPa.

The finished product produced by packaging has high internal stress and strength in BMC material, and the PCB board may experience warping and cracking.

4. BMC materials are difficult to store and require a low-temperature environment. Poor control can lead to failure, deterioration, and solidification.

Disadvantages of BMC process

1. The motor components contain PCBA, and the temperature resistance of the chip capacitors and resistors on PCBA is generally at 105 ℃ because the BMC process is formed at 135 ℃ or above, which poses a risk of damage to the components and makes it difficult to ensure the reliability of the fan during long-term operation.

2. For high current fans, electrolytic capacitors are generally required. The BMC process, which is formed at high temperatures and pressures, has a significant impact on the capacitors, causing electrolyte loss. The capacitor drum seriously shortens the lifespan of the fan operation.

3. The enameled wire of the coil motor is temperature resistant to 135-155 degrees Celsius. Under the BMC process, the polyester protective layer on the surface of the motor wire is damaged, and there is a risk of inter turn short circuit or even high current burning of the equipment during prolonged operation of the fan.

4. The BMC process requires high temperature resistance of the leads, and the parting line of the mold design is located at the lead, so the outlet is prone to water seepage and cause poor fan performance.

5. The process is difficult to control, and the defect rate in the process is relatively high BMC

Advantages of BMC process

1. Low material cost, simple process, and low processing costs

4、 Fully automatic low-pressure vacuum gluing process

1. Adopting a fully automatic glue filling machine, the glue used is imported material with good thermal conductivity. The surface of the motor glue after pouring has a slightly elastic state, which can meet the long-term operation of the motor under high temperature and humidity.

2. The motor is filled with glue in a vacuum environment, and the glue enters the pump body separately and is mixed evenly and thoroughly through a mixing pump. After gluing, there are no bubbles or unevenness on the surface of the motor.

3. The automatic glue filling machine operates in a room temperature environment, with a low-pressure filling motor assembly, which will not damage the electronic components of the motor and has high reliability.

4. This glue filling process has been recognized by many large companies and is already being shipped in large quantities. Dongxingyue's 9238 fans, 12038 fans, 17251 fans, and 20060 fans all use this glue filling method when customers require a waterproof grade of IP68. All cooperative manufacturers that use this glue filling process with Dongxingyue have expressed satisfaction

5. After supplying the fan with this glue filling method to Huawei, the internal double 85 test has been conducted for over 3000 hours, and the AVC has been running for over 5000 hours, indicating extremely high reliability.

Disadvantages of fully automatic low-pressure glue filling process:

1. The cost of glue for pouring is relatively high

2. Fully automatic glue injection requires specialized fixtures for each type of glue injection motor.

Capital Technology Co., Limited is the chief agent of SANYO DENKI, one of the leading enterprises of the cooling fan industry. We are a factory who also have our own independent brand CAPITAL product series. The main products are cooling fan, DC/AC fan, radiator, filter, reactor etc. We can provide customer with the most professional and perfect technical support, welcome to contact me at anytime at rainlee@szcpt.com.