Compared with traditional technologies, the advantages of fiber lasers in beam quality, depth of focus and dynamic parameter adjustment performance have been fully recognized. Coupled with the advantages of electro-optical conversion efficiency, process versatility, reliability and cost, the application level of fiber lasers in medical device manufacturing (especially in fine cutting and micro welding) has been continuously improved.
In welding applications, medium-power fiber lasers ranging from 100W to 1000W can achieve better operational freedom and process control. Pulse widths can range from a few microseconds to CW operation, and pulse repetition rates can reach tens of thousands of Hz, giving applications engineers the ability to optimize processing conditions across a wide range of applications. With proper selection of processing conditions, fiber lasers can weld in thermally conductive, high-energy-density laser keyhole and keyhole conditions.
Based on its overall single-mode fiber structure, fiber lasers are not affected by changes in the focal position caused by thermal lenses due to changes in average power, and output stability is ensured without the need for regular laser cavity calibration or component maintenance.
The outstanding advantages of laser welding are a mature technology used in the field of medical equipment manufacturing:
Precise control of the machining process
The high-quality beam and resulting spot size control, as well as the continuously adjustable average power setting of the fiber laser, ensure accurate and precise control of the welding output energy and focus position. This allows laser welding to be very close to welding locations such as polymer seals, glass-to-metal seals, capacitive components, and welding of heat-sensitive electronic circuits.
Laser welding is a process with zero contact with the welded part, thus eliminating potential problems caused by worn parts, deformation of contacts or contamination. (Wearing of components, and possible deformation and contamination issues during removal).
High-quality sealing seam technology:
Unlike conventional welding or brazing, laser welding can produce high-quality, high-yield, sealed seams, both of which are essential requirements for the manufacture of high-end implantable medical devices.
Figure 1 Example of welding showing process control and sealing weld quality
Reliable surface treatment technology:
In addition to ensuring an aesthetically pleasing weld, the smooth and porosity-free surface treatment technology allows autoclaving to be performed reliably.
Figure 2 Surface quality of laser welded 0.15mm thick stainless steel.