Application: Selectively coat electronic assemblies with precise contours
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, sensors, modules and electronic assemblies. 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:
- sharp edges and defined coating limits
- Short, reproducible switching operations
- Accessibility between high components
- Avoiding overspray on contacts and plugs
- controlled layer thickness in complex webs
- Recipe management for different layouts
Protecting selected areas and keeping functional zones clear
For selective coating, only defined areas of an electronic assembly are covered with protective varnish. Plugs, test points, switches, relays or heat transfer surfaces shall remain free. Precise positioning and a clearly limited spray pattern reduce the amount of masking.
Three-dimensional components create shadow areas. spray angles, web guidance and, where appropriate, several directions of application shall be chosen in such a way that relevant soldering points and conductors are reached.
- Precise Keep-out Zones
- Repeatable component position
- Controlled edge and component cover
- low mist formation
- rapid change of recipe for variants
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 with fast switching times, fine round or flat jet nozzles, precise material pressure controllers, small pressure vessels and axle or robot integration. 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:
- Protection of individual PCB areas
- Coating around components and soldering points
- Clearing of plugs and test points
- Automotive and industrial electronics
- Sensors and power modules
- changing small and medium series
From manual application to automated installation
Component coordinates and spray webs are programmed. Depending on the geometry, several spray angles or a combination of narrow beam and surface application may be required.
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
- less masking
- reduced paint consumption
- Precise release of sensitive areas
- Reproducible coating of changing layouts
- high process reliability
- easy integration into automated production
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.
With original assemblies, tracks, shadow zones, switching points, paint quantity and hardening are tested.
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
In selective coating of electronic assemblies, protective coatings should only reach defined surfaces, while other areas remain free. This reduces masking effort and material consumption and requires a coordinated spraying process in electronics manufacturing, automotive engineering or aviation.
