Workpieces to be diced often consist of several different materials in combination. Using only one type of blade to dice through varying materials can result in frontside chipping, backside chipping, cracks, delamination of films and layers, and other undesirable phenomena. A two-spindle dicer fitted with two different kinds of blade can perform processes that differentiate between frontside and backside requirements to achieve optimal processing results.
Step Cut
The wafer frontside often contains test patterns and metal layers that cause such dicing complications as backside chipping and side cracks, while the wafer backside may also have metal layers and other elements that affect dicing quality. A step cut, in which a different blade is used on each spindle, often solves such problems while providing superior overall results. In the top photograph, a step cut has been employed; in the bottom photograph, a standard single cut has been used.
Bevel Cut
A bevel cut employs on one spindle a V-shaped blade that grooves the surface, and on the other a blade that cuts fully through the wafer. This method can help reduce frontside and backside chipping while improving overall die strength.
