Closed loop control of laser energy from Laser Resources results in precision laser welding and higher quality. Most of the laser applications within the medical device industry are ‘micro’ in nature; on components down to sub-mm in size. These applications include the common laser processes of cutting, welding, marking, drilling and surface treatments but across a wide range of materials and devices, both metallic and plastic, and from implants to instrumentation.
For many years laser micro cutting and laser marking have been core medical product processes. Laser welding however, continues to be a fast growing application area within the medical device sector, and as such poses a new set of challenges for suppliers as they strive to adhere to the rigorous process and quality standards demanded by the industry. A combination of unrivalled application experience and innovative product development has enabled Rofin to provide robust laser welding solutions to the medical device sector.
In an open loop control system, combining pulse shaping with a lamp output that is fluctuating over complicates welded product validation, because as the lamp dynamics change with age the pulse shaping can drift. Experience shows that users will fairly quickly decide either not to use complicated pulse shapes or to replace lamps early. This approach may work for laser welding of stainless steel based devices, which are less sensitive to pulse shaping, but there are other more exotic materials or combinations where pulse shaping is a necessity.
Closed loop control of electrical power and laser output pulse energy however, ensures consistent lamp pump output, consistent laser energy output, and eliminates the interference of back reflections from the work piece. The Rofin laser welding control unit provides such control to pulsed Nd:YAG laser welding resonators and it’s uses allows a pulse-to-pulse stability of ±1% to be achieved over the full range of laser powers, creating a stable and predictable welding process required for medical device production. This results in higher throughput, lower costs and higher quality.