Precision Laser Technology

(Image: Fraunhofer ILT)

Any given modern vehicle has several thousand plug connectors that transmit signal and control voltages throughout the vehicle. Two things present a challenge: there is an increasing number of them being produced and plug connector with contact parts are getting smaller. So researchers at the Fraunhofer Institute for Laser Technology ILT—as part of the ScanCut Project that also includes  KOSTAL Kontakt Systeme GmbH, Pulsar Photonics GmbH and Amphos GmbH developed a hybrid manufacturing process to laser cut thin-walled metal strips that are used in contact parts. It combines a helical-beam optic with a multi-beam module. The laser beam power is provided by a high-power USP beam source. The ability to create contact areas with several independently sprung contact points in tiny installation spaces is particularly advantageous as the redundancy of multiple contact points enables even the smallest contact systems to provide the kind of robust electrical design that is so important for reliable signal transmission.

The laser-based helical drilling process being used is a high-precision alternative method to the traditional mechanical methods that are deployed.

They are using ultra-short pulse (USP) lasers. Fraunhofer has patented the process using the USP approach and has shown its usefulness in drilling high aspect ratio precision micro-holes in steel, glass and ceramic. While the process is precise—the focus diameter is 25 μm, with a roughness Ra at the borehole wall of less than 0.5 μm—it is also comparatively slow.

So, through the ScanCut project, they worked to make it more productive with multibeam optics.  “In the project, we combined our helical drilling optics with a multi-beam module from Pulsar Photonics GmbH and a high-power beam source from Amphos GmbH,” says Jan Schnabel, a scientist in the Micro and Nano Structuring group at Fraunhofer ILT. “That allowed us to combine the precision and quality of the helical drilling process with the productivity of multi-beam processing.” The system uses an Amphos GmbH-developed high-power beam source based on InnoSlab technology, with an output power of 300 W and a pulse energy of 3 mJ.