Application: Precisely spray soldering flux in electronics production
What this application is about
Various wet-spray processes are suitable for industrial application. Depending on the medium, component geometry, batch size and quality requirements, application can take place with a manual paint spray gun, a coating gun, an automatic spray gun or within a painting and coating system.
What the coating must achieve in the process
The application mainly concerns printed circuit boards, contact surfaces, wires, solder assemblies and metallic fasteners. The required effect occurs only when coating material, substrate, layer thickness and subsequent drying or curing fit together. The spraying process must therefore be adapted to the concrete material system and the real production conditions.
Alongside surface quality, material consumption, cleaning effort, system availability and reliable repeatability also matter. A sound technical solution therefore combines controlled atomisation with a stable material supply that is easy to regulate.
Challenges in spray application
Even small fluctuations in material pressure, viscosity, distance or movement control can change the coating visibly or functionally. Typical requirements include:
- very small, reproducible application quantities
- uniform wetting without dripping
- precise switching in cyclic processes
- preventing overspray on areas that must remain uncoated
- resistant seals and wetted components
- rapid flushing during production interruptions
Controlling flux quantity and wetting precisely
Flux spraying requires a thin, uniform application. Excess flux can increase residues and cleaning work, while insufficient or interrupted wetting can impair solderability. Spray width and application quantity must therefore match the assembly, soldering process and line speed.
Alcohol-based and water-based fluxes have different requirements for evaporation, extraction and material compatibility. Contact surfaces, connectors and areas that must remain uncoated are protected through positioning, masking or selective spray paths.
- uniform wetting with a thin film
- defined uncoated areas and edges
- constant material pressure during short spray pulses
- consideration of the drying and preheating sections
- safe extraction and rapid cleaning
Krautzberger application technology for this application
Krautzberger treats application and material supply as a connected system. Depending on the task, manual and automatic spray guns, suitable air and material nozzles, material pressure tanks, diaphragm pumps, pump and lifting stations, and material pressure regulators can be combined.
In automated processes, spray guns can be integrated into mounts, lifting devices, axes or robots. Material changeover valves and flushing equipment support applications with several colours or media. The specific selection depends on viscosity, solids content, application quantity, cycle time and component geometry.
For fine surface finishes, various XLINE nozzle combinations and spray patterns are available. With highly viscous, abrasive or sedimenting media, sufficiently large flow cross-sections, suitable material combinations, agitators and pressure-stable delivery become more important.
The focus is on compact automatic spray guns for short switching times, fine nozzles, material pressure vessels for small quantities as well as precise material pressure controllers and, if necessary, material change or rinsing devices. The technically and economically suitable combination is selected for the specific medium, components and required production output.
Typical components and areas of application
The application is used in different industries and component groups. Typical examples are:
- printed circuit boards before shaft or selective soldering
- Contact and connection areas
- Wire and cable assembly
- Small series and repair soldering stations
- automated electronics production
- special metal joints with local flux application
From manual application to automated installation
For manual application, simple dosing and a clear view of the assembly are priorities. In indexed lines, spray duration, distance, spray width and delivery pressure are synchronised with assembly transport.
In addition, component feed, extraction or ventilation, cleaning, media change and accessibility for maintenance work must be taken into account during the system integration. This keeps the process stable not only in the pattern run, but also in everyday production.
Advantages of a coordinated spray solution
- even activation of the soldering surfaces
- reduced flux consumption
- less residues and cleaning effort
- Reproducible solder preparation
- precise integration into indexed systems
- fast adaptation to assemblies and batch sizes
Application trials at the Krautzberger technical centre
Liquid media and coating materials with similar names can differ considerably in viscosity, solids content, solvent base, wetting and drying. A reliable choice of spray gun, nozzle and material supply should therefore be made using the original material and a representative component.
In the technical test centre, wetting image, spray mist, quantity of material and switching behaviour can be evaluated with the original flux medium and representative components.
On this basis, the spray pattern, material quantity, pressure, distance, movement and cleaning sequence can be defined. The result is an application solution suited to the medium, the geometry and the intended production process.
Related products
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Matching solution for your process
Looking for a spray gun, an automatic spray gun or a complete material supply for this process? Krautzberger helps you select and design suitable spray technology, nozzle configurations, delivery and regulation.
Contact Krautzberger to discuss your medium, component, production volume and desired result. Together, we assess how the process can be implemented safely and economically.
Industries for this application
During soldering, the correct amount of flux determines wetting of the contact surfaces without leaving unnecessary residues. Targeted, uniform application is therefore especially important in electronics manufacturing.
