SEHO Systems’ Christian Ott to Hold Process Control Presentation at SMTAI 2010

Compared to other soldering processes, the selective soldering process is considered to be particularly demanding. Structures with small pitches or distances to neighboring components result in a small process window and provide less room for potential failures.

From conventional wave soldering, we already know that variable parameters such as the flux quantity, preheat time, temperature or wetting time, and solder temperature can play a decisive role for a “high quality or low quality solder joint. These variable parameters are to be considered even more critical in selective soldering processes. Therefore, precision and accuracy of the equipment are a must to avoid costly rework.

A controlled and reliable selective soldering process is a basic requirement for approaching zero-fault-production. Even potential operator faults should be detected and, if possible, have to be eliminated by the machine.

Modern control units and easy-to-handle software provide the basis for complete process control and thus build the cornerstone for a cost-effective selective soldering process. Control functions for the different process steps such as fluxing, preheat and soldering, as well as additional features such as fiducial recognition or process visualization are very decisive. On the other hand, they are helpful tools to ensure a reliable selective soldering process.

This paper will give a comprehensive survey about the single process steps and the possibilities that exist to monitor and control them.