High efficiency micro-welding using high brightness lasers with tailored beam properties

Micro-welding using single-mode fiber lasers is well established and has been widely reported, however there are situations where the gaussian beam shape does not lend itself to this application and problems can arise due to the centre of the beam being too intense and the outer limits of the beam causing heating effects around the weld. In such instances it is preferable to use a beam intensity profile which is more suited to the application. By tailoring the parameters of the laser, it is possible to control the intensity profile of the incident working spot and therefore improve the spot weld quality. In addition there is a gain in the efficiency of the welding process since the beam has a more appropriate shape. In this paper the scope of the spot welding capabilities of this system are examined, and key parameters such as process speed and process tolerance are considered.