Feature Article

"Reflection diagnosis gives us an innovative measurement tool to verify successful welding," says Frank Brunnecker, vice president of the plastic welding division at LPKF Laser & Electronics AG. As of autumn 2010, reflection diagnosis will be available as an option on the company's welding systems.

Reflection diagnosis makes use of the physical effect of light reflection at boundary surfaces. Before welding, there are, in effect, two boundaries between components. When laser light impinges on these boundaries, a certain amount of light can be reflected. Areas that have been welded together have no such double boundary and the amount of reflected light is reduced.

This method also allows the quality of a welded seam to be evaluated during the welding process. The integration of the reflection diagnosis system into the laser head gives the LPKF LQ-TwinWeld3D hybrid welding system suitable for sensitive components. According to the manufacturer, the technique can help reduce reject rates and deliver robust quality documentation for each individual component.

Reflection diagnosis complements existing quality assurance systems, such as melt-travel monitoring, pyrometer testing and burn detection. Depending on the specifics of each product, the various methods can be implemented to allow full tracking and tracing of individual components.

LPKF Laser & Electronics AG, Plastic Welding Division
Erlangen, Germany;  +49 9131 616 5717
www.laserquipment.de