Transient characteristics of post-welding shift of TO-can pigtail package

The dynamic properties of laser welding post-welding shift (PWS) for a TO-can pigtail package are studied. We use non-contact capacitive displacement sensors to measure the transient movement of the welding parts right after firing the laser pulse(s) for the welding configurations using (i) a single and (ii) three-symmetric laser beams. We measure the transient behaviour of the PWS of the welded posts at various time scales. From our result, multiple time scale dynamic behaviours of the PWS are observed and this gives us some insight on the possible physical processes contributing to the PWS.