Wafer dicing by laser induced thermal shock process

In this report, a new way of wafer dicing is carried out by laser induced thermal shock process. This system consists of the use of a Nd:YAG laser to heat up the wafer surface following by a cooling fluid along the scanned line. The temperature gradient created by the laser heating and the gas cooling will cause a micro-crack on the wafer surface along the scanned line and the resulting crack propagation finally separate the silicon wafer into two pieces. As there is no material loss and removal during the separation process, the wafer dicing line width can be as small as sub-micron. The cross section of the wafer is smooth comparing with other separation methods and a high separation speed of 70 mm/s is achieved.