Thermographic Monitoring of Flux Application
Process Reliability Redefined.
Awarded 2nd place in the Future Markets cluster at the productronica Innovation Award 2025!
Your Advantages at a Glance
Process Monitoring
A previously unmonitorable step in the soldering process becomes controllable.
Quality Improvement
Improvement of product quality through early fault detection.
Cost Reduction
Reduction of rework and scrap, and automatic process approval.
Zero-Defect Strategy
Automatic removal of defective assemblies before soldering.
The application of flux is a key prerequisite for flawless wave or selective soldering. The flux removes oxide layers from the metal surfaces to be wetted and prevents re-oxidation. Only then is the soldering process and a metallurgically perfect solder joint possible.
The decisive factors for soldering quality are not only the chemical effectiveness of the flux, but above all the exact dosage and precise location on the circuit board.
Too little flux can lead to typical soldering defects such as incomplete penetration or cold solder joints. Too much flux increases the risk of flux residues, which may require additional process steps or impair the function of the assembly.
Previous solutions for monitoring flux application have generally relied on random sampling, for example, using test assemblies or by monitoring the function of the fluxer nozzle.
However, these approaches are not integrated into the process and do not allow conclusions to be drawn about the actual flux application on the individual assembly.
Our New Solution for You:
Process-Integrated Thermographic Flux Control
The first inline-compatible, automated control of flux application for each individual printed circuit board – directly in the manufacturing process!
The method utilizes the physical property that heat is locally extracted from the printed circuit board when the solvent in the flux evaporates. As a result, wetted areas have a lower surface temperature than untreated or insufficiently fluxed areas.
This effect is captured and evaluated immediately after the flux is applied using a thermal imaging camera.
Here’s how it works:
The flux application is captured within a defined period after fluxing.
The wetted areas are analyzed in terms of their location and extent by evaluating the temperature differences.
Automated decision on whether the assembly is approved for the soldering process.
The soldering process is only continued automatically if there is clear conformity with the predefined target values.
Result:
Precise process control, reduced error costs, higher overall efficiency.
100 % Process Coverage
Closes existing gap in process monitoring.
Scrap Reduction
Incorrect flux application detected before soldering.
Efficiency Gain
Increased production efficiency through less rework.
Our Vision:
Autonomous Manufacturing
Thermographic flux control is already prepared for integration into the SIEMENS Industrial Edge ecosystem.
At the same time, the system creates the necessary database for future AI-based data analysis with the aim of automatically optimizing process parameters in real time. This lays the foundation for continuous process improvement in the spirit of adaptive manufacturing.
You have any questions? We look forward to hearing from you!
Thermographic monitoring of flux application is a joint development by SEHO Systems GmbH and SIEMENS AG, Foundational Technologies, Berlin.
FAQ about Thermographic Flux Control
Why is flux application so important for soldering?
The flux removes oxide layers from the metal surfaces to be wetted and prevents re-oxidation. Both are crucial for a metallurgical clean and reliable solder joint. Without correct flux application, the soldering process can be prone to errors.
What problems can arise if the flux is incorrectly dosed?
If too little flux is applied, typical soldering defects such as incomplete penetration or cold solder joints can occur. If too much flux is used, there is an increased risk of residues, which may impair the function of the assembly.
Why are existing control methods for flux application insufficient?
Conventional methods are often based on random sampling, e.g., with test assemblies. Alternatively, the pure function of the flux nozzle is monitored. However, these approaches are not process-integrated and do not allow conclusions to be drawn about the actual application on the individual circuit board.
What exactly is thermographic monitoring of flux application?
Thermographic monitoring uses a thermal imaging camera to measure temperature differences on the printed circuit board immediately after flux application. When the solvent in the flux evaporates, heat is extracted locally from the PCB, meaning that wetted areas are cooler than areas with insufficient flux. These temperature differences are evaluated and provide an accurate picture of whether and where the flux has been applied and in what quantity.
What advantages does automated control offer compared to previous methods?
With the inline-compatible, automatic control, each individual circuit board can be checked immediately after flux application. This enables 100 % process monitoring and allows defective assemblies to be removed before actual soldering. This reduces scrap and rework, increases the quality of the end products, and boosts overall manufacturing efficiency.
What impact does thermographic monitoring have on quality, costs, and process reliability?
Early fault detection and automatic removal of faulty assemblies improve product quality. At the same time, costs for rework and scrap, or potentially faulty solder joints are reduced. Overall, this leads to greater process reliability and more efficient production control.
How does this new technology fit into modern manufacturing concepts and future strategies?
The solution is already designed for integration into the SIEMENS Industrial Edge ecosystem and creates a database that can be used for AI-supported data analysis and automated optimization of process parameters in real time: a step forward adaptive, autonomous manufacturing processes.
