Zero-fault production at productronica

Typically, manual rework processes are almost non-reproducible and often cannot be performed with the required high quality. In addition, manual rework is time-consuming and cost-intensive, and hidden costs such as productivity rates or staff training need to be considered. The zero-fault production line from SEHO is designed for selective soldering of through-hole components, free from defects and completely traced.

Besides the selective mini-wave soldering process, this production line incorporates automated optical inspection (AOI) of the solder joints, a verify workstation for verification and classification of detected faults as well as a defined and automated rework soldering process according to the respective soldering defect. Intelligent handling units automatically allocate the assemblies to the next work station. All modules in this zero-fault production line are linked with a bi-directional data transfer. All process and machine data is completely recorded, analyzed and documented. Fully reproducible and operator-independent processes, automatic rework of only verified defects, not the entire board, and no influence on the cycle time of the overall system are only a few of the outstanding advantages of this zero-fault production line from SEHO.

New concepts also are required in the field of wave soldering in order to meet the goal of a defect-free production. For this purpose SEHO developed a new system where all process-relevant components – fluxing, preheating and soldering – have been replaced by new, innovative modules. To activate the surface of the PCB prior to wave soldering, typically a solvent-based flux is applied. Alternatively, now a plasma process can be used to deposit flux powder, so a solvent can be avoided.

Due to reduced residues, product quality and downtime of the system can be improved. Preheating of PCBs, especially for the increasing share of power electronics, requires a high energy density. This can be implemented efficiently by using new infrared emitters that offer extremely good heat transfer and are only activated in the areas where a PCB is located. This can be achieved by the fast response of the emitters, an exact PCB monitoring system and newly developed software.