Selective Flux Ultrasonic Coating System

The Selective Flux Ultrasonic Coating System is an advanced, high-precision automated device designed specifically for the selective soldering process in electronics manufacturing. It replaces the traditional spray or foaming process used in wave soldering, as well as manual application methods.

The core principle is to use ultrasonic energy to atomize liquid flux into extremely fine particles (forming a fine mist or aerosol). Then, through a precision nozzle or printhead, under program control, the flux is selectively and non-contactly applied to the specific areas of the printed circuit board (PCB) where soldering is required, such as the leads and pads of through-hole components or the solder joints of surface-mount devices (SMDs) requiring localized soldering.

Selective Flux Ultrasonic Coating System - Cheersonic

Key Workflows

1. Programming: The precise location, shape, and amount of flux to be applied are pre-programmed based on the PCB design file (Gerber) or CAD data.
2. PCB Positioning: The system precisely positions the PCB on the work area.
3. Ultrasonic Atomization: Liquid flux is delivered to the ultrasonic atomizer. High-frequency ultrasonic vibrations break the flux into micron-sized droplets.
4. Selective Spraying: A programmable nozzle (typically carried by a multi-axis robotic arm) moves over a predetermined location. Compressed air or nitrogen forces the atomized flux out of the nozzle, forming a directed, controllable flux spray stream that precisely covers the target area.
5. Drying/Preheating: After coating, the PCB typically enters a preheating zone to evaporate the solvent in the flux, leaving behind the active ingredients in preparation for the subsequent soldering step (typically selective wave soldering or laser soldering).

Advantages

Selective flux ultrasonic coating systems offer significant advantages over traditional flux coating methods:

1. Extremely high precision and selectivity:

  • Precisely applies flux to tiny, complex solder joints and pins, preventing contamination of non-solderable areas (such as connectors, gold fingers, test points, and areas around delicate ICs).
  • The minimum dot diameter can reach sub-millimeter levels, making it ideal for high-density, fine-pitch PCB assembly.

2. Significantly reduces flux consumption:

  • Coating only the areas requiring soldering avoids the significant flux waste associated with full-body spraying or foaming (typically resulting in a 70-90% waste rate).
  • Directly reduces flux procurement costs.

3. Improved product reliability and cleanliness:

  • Reduced residue: Flux residue is concentrated near the solder joint, away from sensitive areas, significantly reducing the risk of residue-related chemical electrochemical migration (CAF), corrosion, and leakage.
  • Reduced Cleaning Requirements: For products requiring no-clean processes or requiring high reliability (automotive, medical, aerospace), this reduces the difficulty, cost, and environmental impact of subsequent cleaning. For products requiring no cleaning, this improves final cleanliness.
  • Bridging Avoidance: Precise application reduces the possibility of solder bridging caused by excessive flux accumulation in dense areas.

Selective Flux Ultrasonic Coating System - Cheersonic

4. Improved process consistency and repeatability:

  • Automated and programmable control eliminates the variability of manual coating.
  • Precise control of coating volume (volume or thickness) ensures consistent and appropriate flux levels for each solder joint, improving soldering yield.

5. Enhanced adaptability to complex designs:

  • Capable of handling complex PCB designs with tall and densely packed components, shielding covers, connectors, and other features that hinder traditional spray or wave soldering.
  • Easily handles double-sided boards (bottom-side-only soldering) and spot soldering requirements.

6. Reduced maintenance and downtime:

  • Eliminates the problems of traditional foaming tanks or spray chambers, nozzle clogging (due to different atomization methods, high flux utilization, and slow impurity accumulation), and flux crystallization.
  • The system is generally easier to clean and maintain.

7. Reduced environmental impact and operating costs:

  • Reduced VOC emissions: Flux consumption is significantly reduced, directly reducing volatile organic compound (VOC) emissions.
  • Reduced waste disposal: Reduced amounts of excess flux and cleaning solvents are wasted. Energy Saving: Reduces energy consumption for flux heating (e.g., foaming tanks) and ventilation systems.

8. Compatible with Various Flux Types:

  • It is generally compatible with various types of no-clean and washable fluxes, including water-based and alcohol-based fluxes, and even certain low-solids solder pastes (for specialized applications).

9. Improved Production Efficiency:

  • Integration into automated production lines delivers high speeds and reduces manual intervention.
  • Precise coating reduces soldering defects, lowers rework rates, and improves overall output.

Selective Flux Ultrasonic Coating System - Cheersonic

Ultrasonic selective flux coating systems are a critical precision technology in modern high-reliability, high-density electronics manufacturing. Through ultrasonic atomization and programmed selective spraying, they achieve extremely precise and efficient flux application, offering significant advantages such as cost savings, improved product reliability, improved process consistency, and enhanced environmental friendliness. They are a key enabler for the successful implementation of selective soldering processes. Their application is increasingly widespread in sectors with stringent quality and reliability requirements, such as automotive electronics, industrial control, communications equipment, medical electronics, and aerospace.

About Cheersonic

Cheersonic is the leading developer and manufacturer of ultrasonic coating systems for applying precise, thin film coatings to protect, strengthen or smooth surfaces on parts and components for the microelectronics/electronics, alternative energy, medical and industrial markets, including specialized glass applications in construction and automotive.

Our coating solutions are environmentally-friendly, efficient and highly reliable, and enable dramatic reductions in overspray, savings in raw material, water and energy usage and provide improved process repeatability, transfer efficiency, high uniformity and reduced emissions.

Chinese Website: Cheersonic Provides Professional Coating Solutions