Maximum Process Control for SEHO Selective Soldering Systems
SEHO Systems GmbH, a worldwide leading manufacturer of soldering systems, sets a new milestone for the control of automized selective soldering processes.
Particularly in selective soldering, the precision of the process plays a decisive role. This primarily applies also for the flux application. During the last few years, micro drop jet fluxing has turned out to be the most suitable method. Drop jet fluxers guarantee exact flux application to the point with a precisely defined quantity, thus ensuring that surrounding areas which are not meant to be soldered, will not be wetted.
On the other hand it has to be assured that enough flux gets to the solder joint so that a sufficient hole fill is achieved to form high quality solder joints during the subsequent soldering process.
Flux control systems are, therefore, essential. However, existing units only control the function of the drop jet nozzle. This usually is performed in a test cycle prior to the actual flux application to the printed circuit board. During this test cycle a specific sensor is wetted with flux. This sensor shows whether the function of the nozzle is alright at the time of the test. It is, however, not possible to make a statement about the function of the drop jet nozzle during the actual production process and moreover the flux quantity being applied to the board cannot be clearly defined.
This is the point where the new real time and real quantity drop jet fluxer control from Seho applies.
The new flux control system from Seho does not only monitor the function of the drop jet nozzle. It in fact measures the actual flux quantity jetted by the drop jet nozzle during the fluxing process. The measured quantity is compared with a reference value learned earlier. In case the system detects a deviation, an error message will be initiated. In addition, the software clearly indicates, which part of the printed circuit board has not been fluxed correctly.
Thus, the real time and real quantity drop jet fluxer control ensures highest process reliability and constant process conditions without any influence on the cycle time.
