More and more complex devices are being manufactured in accordance with Moore's law. In order to improve the device performance, new techniques as well as new materials are being used. Epi layers, nitride, and oxide layers are a common site on the wafers when they get to the backgrinding stage.
It’s difficult for the standard backgrinding wheel to grind these wafers, resulting in force outs, higher stresses in the wafers, and wafer breakages in extreme cases.
Our team has developed a special coarse grinding wheel that is gentler on the wafers and can easily grind the hard layers. This prevents frequent dressings and also imparts lower stresses on the wafer surface.
Depending on the machine tool being used, the coarse wheel specification is optimized for the best performance. Normally, a COARSE#3 (#320) wheel is recommended with an engineered bond system for free cutting action.
The standard fine grind wheels or the special wheels for thin wafer grinding can be used in conjunction with the hard to grind coarse wheels.