Drilling
| BOOTH 45 E 160.3 | Drilling with Laser Radiation Laser drilling enables the machining of different materials like steel, high-strength materials, multi layer systems, ceramics and plastics with high reproducibility and productivity. It offers an alternative manufacturing method to mechanical drilling, electric discharge machining (EDM), electro chemical machining as well as electron beam drilling. Laser drilling is applicable for many manufacturing demands in industry due to the small achievable hole diameters, the high flexibility (e. g. different diameters and inclination angles) and the large attainable aspect ratios. A short cycle time and low production costs can be realized by the short drilling duration and "on the fly" machining. Especially for the manufacturing of cooling holes in turbo engines parts drilling with laser radiation allows to machine multilayer systems (e. g. substrate, bond coat and thermal barrier coating) at acute inclination angles. Contact Person Dipl.-Phys. Mihael Brajdic Phone +49 241 8906-205 mihael.brajdic@ilt.fraunhofer.de Fraunhofer Institute for Laser Technology ILT | |
| BOOTH 44 E 160.2 | Helical Drilling Optics For many high grade applications, i.g. in the fields of power and drive engineering, for automotive and microfluidic applications, filter technology or the production of textile fibres, high-precision drillings with large aspect ratios and exceedingly good surface quality are required. For these applications precise and round holes with diameters in the range from 40 up to 300?m with defined taper are needed. Using short- or ultrashort pulse lasers to fabricate these holes by percussion drilling has the disadvantage that the laser beam quality has to be very high as the profile of the beam is mapped onto the cross section of the hole. By using the helical drilling technique, where the beam is rotated in itself, this problem is overcome and precise round holes can be drilled. Also, the taper of the holes can be adjusted. The helical drilling optics is implemented in a precise positioning system. Therefore it is possible to drill any hole patterns with different programmable diameter and taper at a positioning tolerance of < 10?m. Contact Person Dipl. Ing. Rahel Kruppe Phone +49 241 8906-311 rahel.kruppe@ilt.fraunhofer.de Fraunhofer Institute for Laser Technology ILT | |
| BOOTH 26 E 100.K1 | High Rate Percussion Drilling of Silicon Wafers for EWT Solar Cells The research and development in the field of solar cells for terrestrial applications is focusing on lowering production costs. The conventional way of interconnecting cells by soldering highly conductive tabs to the front and rear of neighbouring cells is however nearing the limit of what is possible in terms of cell efficiency. A different approach to contacting the cells is placing both negative and positive terminal to their rear surface. One back contact cell concept is called emitter wrap-through. Here, several thousands of through-holes are drilled through the wafer. In a subsequent step the emitter is diffused through these holes to form the contact regions on the rear side. Up to 1 hole per mm2 is needed to achieve suitable series resistance values, resulting in up to 25,000 holes per wafer. The system shown in this demonstration uses a Rofin Stardisc, emitting at 1030nm, which is capable of drilling vias with 4 to 6 pulses of a pulse energy in the range of 4mJ and a pulse length of ?s. The drilling speed is in the range of 2500 vias per second. Contact Person Dr. Malte Schulz-Ruhtenberg Phone +49 241 8906-604 malte.schulz-ruhtenberg@ilt.fraunhofer.de Fraunhofer Institute for Laser Technology ILT | |
| BOOTH 47 1160.3 | Transparent Metal - High Speed Laser Micro Drilling Filters, nozzles and membranes are a key component for many products not only in medicine- and bio-technology but also in the fields of mechanical and automotive engineering. These applications require holes with diameters smaller than 30?m and drilling rates of more than 1000 holes per second which cannot be met by conventional drilling methods. Due to an adapted laser drilling method with a scanning system a special machining strategy for high speed laser micro drilling of metal foils was developed. The arrangement of the holes and the drilling strategy of the single holes can be adapted very fast by a CAD-CAM coupling and therefore easily adapted to the customer demands. It has been shown that micro holes can be drilled in up to 100?m thick metal foils with diameters of 30?m down to less than 5?m by drilling rates of up to several 1000 holes per second. Contact Person Dipl.-Ing. Claudia Hartmann Phone +49 241 8906-207 claudia.hartmann@ilt.fraunhofer.de Fraunhofer Institute for Laser Technology ILT |
