Ultrasonic Flux Spraying Technology

Ultrasonic flux spraying technology is an advanced process that uses high-frequency ultrasonic vibration to atomize liquid flux into tiny particles and spray them evenly on the surface of PCB boards. Compared with traditional air pressure spraying or foaming coating methods, this technology has significant advantages such as uniform spraying, precise dosage, and no splashing. It has become an indispensable key process in modern electronic manufacturing.

Technical principle

The core component of the ultrasonic flux spraying system is the ultrasonic atomizer, and its working principle mainly includes the following key links:

1. High-frequency vibration generation: The piezoelectric ceramic transducer generates mechanical vibration under the drive of a high-frequency electrical signal of 20kHz-120kHz

2. Capillary wave formation: The vibration is transmitted to the flux liquid surface at the nozzle to form a stable capillary surface wave

3. Atomization process: When the vibration energy exceeds the surface tension of the liquid, the droplets separate from the wave crest to form uniform droplets with a diameter of 10-50μm

4. Directional spraying: The atomized particles are directed and deposited on the PCB surface under the drive of the carrier gas to form a uniform film with controllable thickness

Technical advantages

1. Excellent spraying quality

Uniform and fine atomized particles (D50 is usually 15-30μm)

Controllable coating thickness (typical range 3-8μm)

Surface coverage consistency > 95%

No "bridging" or "missing spray" phenomenon

2. Improved process efficiency

Spraying speed can reach 300-600mm/s

Line change time is shortened by more than 50%

Online real-time monitoring and adjustment can be achieved

3. Cost savings

Flux utilization rate is as high as 90-95% (traditional methods are only 60-70%)

Maintenance cycle is extended by 2-3 times

Scrap rate is reduced by 40-60%

4. Environmental protection and safety

VOC emissions are reduced by 30-50%

No safety hazards caused by high-pressure gas

Working noise < 65dB

Key process parameter control

1. Atomization parameters

Frequency selection: usually 80-100kHz (balance atomization effect and output)

Amplitude control: 0.5-5μm adjustable

Temperature management: maintain 25±2℃

2. Fluid properties

Viscosity range: 10-50cP recommended

Solid content: 8-15% is optimal

Surface tension: needs to be <35mN/m

3. Motion control

Nozzle-PCB distance: 15-25mm

Spraying angle: 70-90°

Closed-loop control of scanning speed and atomization volume

Ultrasonic flux spraying technology is continuously driving the electronic assembly process towards a more precise, environmentally friendly and intelligent direction. With the explosive growth of emerging fields such as 5G, the Internet of Things, and automotive electronics, this technology will play a more critical role in ensuring welding quality, improving production efficiency, and reducing manufacturing costs.