Since 2018, KRIWAN Industrie-Elektronik GmbH uses the Selective Mini-Wave Soldering Module IW1 from EUTECT.
For the PTC pill soldering process used in-house at KRIWAN, the experts at EUTECT customised the IW1 high-temperature soldering module to meet the specific requirements. In this system, the solder bath is automatically heated to 400 °C and lowered to 365 °C during operation, which is an extremely low process temperature for the customer-specific application. "The IW high-temperature soldering module from EUTECT, which is based on solid mechanical engineering technology, therefore fulfils an extremely important requirement for us," emphasises Volker Wassermann, Industrial Engineer at KRIWAN Industrie-Elektronik GmbH.
Process-stable module
With the selective mini wave soldering module from EUTECT, a flowing solder wave is generated by pumping up the molten solder from a heated solder tank using an induction pump. Product-specific, quick-change solder masks and solder nozzles focus the solder flow on the actual solder joint. The coordinated solder nozzle and solder mask limit the flow of solder and thus prevent increased thermal stress and preliminary damage to the soldering process environment.
"An extremely advantageous attribute of the mini wave soldering module is the outer tube, which has its own heating, because higher temperatures can be set here compared to the heat levels in the module. Mini wave soldering systems with an unheated outer tube, on the other hand, require up to 3 hours to reach operating temperature again after long downtimes," says Wassermann. With the IW soldering module from EUTECT, a nitrogen protective gas atmosphere can be applied very closely to the rising solder flow thanks to a product-specific gas bonnet. The gas flow is channelled through the soldering module. As the gas rises in the soldering nozzle, preheated nitrogen emerges from the gas bonnet. During the soldering process, the hot nitrogen atmosphere supports selective flux activation and deoxidisation of the surfaces to be wetted. This promotes solder penetration in the direct process environment, particularly at higher thermal masses, without thermally stressing neighbouring components. The meandering solder reflux also reduces slag formation.
The IW selective mini wave soldering module also offers other options, such as solder wave height control using a laser light band. A laser continuously measures the height of the solder wave and automatically adjusts it if the process height deviates. An automatic wire feed keeps the solder bath level constant. This technology therefore enables a reproducible overall process with complete operating data acquisition. High-precision inject fluxing, splash-free brush fluxing, area-efficient spray fluxing or cycle time-optimised lift-dip fluxing, on the other hand, enable the precise application of flux. Eutect also creates customised heating algorithms tailored to the nozzle. Another advantage is that the shaft is available comparatively quickly after a service, for example.
The IW soldering module from EUTECT also has a transversely installed induction pump, which is why slag particles mainly settle in the bath. "The service and maintenance intervals for the IW soldering module are comparatively short, which has a positive effect on downtimes," emphasises Wassermann. For example, the EUTECT system, which runs 24/7, requires 10-15 minutes of maintenance twice a week and around 30-45 minutes once a month. The kinematics used by EUTECT work with almost constant precision and reproducibility. For example, the soldering position of the lifting table only needs to be adjusted slightly around four times a week. "Before we used the IW soldering module from EUTECT, we had to schedule 20-30 minutes a day and 30-60 minutes a week for maintenance and also clean the nozzles every 1-2 hours and readjust them if necessary," explains Wassermann.
Thanks to planar and spring-loaded solder tank heating plates with integrated heating cartridges and temperature sensors, the IW soldering module also enables the wear-free transfer of heating power from the solder tank to the molten solder over the long term. Specific coatings protect the surfaces of the solder tank, solder pump and solder nozzle located directly in the molten solder against deposition and wear and also allow longer component service lives in the solder. The solder bath temperature is also monitored twice. "With the mini wave soldering module from EUTECT, we were able to significantly reduce the maintenance intervals and at the same time significantly increase the overall availability of the system in production operation. This is a major advantage, as frequent breakdowns of soldering systems put a considerable strain on budget planning," Wassermann emphasises in conclusion.