Introduction of Scattering Ultrasonic Nozzle

Oct 02, 2024

Scattering nozzles use low-pressure air/gas to produce uniform, wide spray patterns, with each nozzle capable of up to 9.8 inches (25 centimeters), depending on the distance from the substrate. The speed of the air flow is controllable to allow low or high impact of the atomized spray on the product or substrate. Multiple nozzles connected in series can achieve infinite width. Scattering nozzle design is used for highly repeatable wide patterns in slender nozzles.

The scattering type ultrasonic nozzle is an ultrasonic atomizing nozzle with a cyclone cone spray. It uses the ultrasonic atomization nozzle technology, and through the special vortex flow channel design, the carrier gas is converted into a uniform rotating airflow, so that the ultrasonic atomization of the liquid mist is dispersed in the form of a cyclone spray, expanding the spray area of the atomizer. Ultrasonic nozzles can also be sprayed on vertical or curved surfaces and other angular substrates.

The typical application of scattering ultrasonic nozzles is photoresist coating on semiconductor chips, where photoresist is sprayed onto the semiconductor chips. Due to the rotational scattering of the mist emitted by the scattering type ultrasonic nozzle, a uniform photoresist film can be formed not only on the wafer plane, but also on the sidewalls and corners of the wafer microstructure. In addition, the scattering type ultrasonic nozzle can also be used for thin film solar cell coatings, calcium titanate solar cell coatings, AR transmission and reflection film coatings, thermal insulation film coatings, superhydrophobic coating coatings, PCB flux coatings and other applications.

Ultrasonic Spray Coated Machine 4

Principle:

Ultrasonic nozzles convert high-frequency sound waves into mechanical energy through piezoelectric transducers, and then convert the mechanical energy into liquid. This longitudinal upward and downward vibration generates standing waves in the liquid film at the tip of the ultrasonic nozzle, where the amplitude of these waves can be controlled by a power generator. These stationary liquid waves can extend upwards from the top of the ultrasonic nozzle, and when the droplets leave the atomizing surface of the nozzle, they are decomposed into a uniform fine mist of micrometer sized droplets.

Unlike pressure nozzles, ultrasonic nozzles do not use high pressure to force liquid through a small hole to produce spray. The liquid enters through a relatively large nozzle center without pressure and is atomized by ultrasonic vibration inside the nozzle.

Each ultrasonic nozzle operates at a specific resonant frequency, which determines the median size of the droplet. The difference in droplet size is very small, and its distribution can be accurately predicted within a certain range through mathematical calculations. For example, a 120 kHz nozzle produces a median droplet size of 18 microns when spraying water. The higher the frequency, the smaller the decrease in median value.