Lasag SLS 200 GX trials spot on copper laser welding solution
The SLS 200 GX laser welder from Rofin's Swiss subsidiary Lasag uses a patented process for welding copper that will be of special interest to those making electrical connections in electronics manufacture. Welds produced are more consistent in diameter and penetration. Also very small spot welds (down to 25 microns diameter) are possible.
At room temperature copper absorbs as little as 5% of laser light at 1 micron wavelength, explains Rofin-Baasel UK, so copper has traditionally required pulsed high peak power laser welding to overcome the metal's inherent high reflectivity and thermal conductivity.
With the SLS 200 GX, which is being offered for application trials, a secondary wavelength at 532 nm (10-15% of total energy) is mixed in, which improves the absorption of laser energy. Following the initial pulse of green light, the energy is reduced, but the main infra-red energy is maintained to allow the weld pool to grow. Molten copper absorbs the laser energy much better than solid material at room temperature.