It is required to grind wafers with bumps on the front side to thin down the overall thickness. This poses a challenge in terms of wafer yield. The bumps/ink dots now become stress concentration points and increase the chances of wafer breakage during grinding or while transporting the wafers from and to the grind station.
In such a situation, it is necessary to use a very gentle grinding wheel that will grind the wafer, but at the same time exert as low a pressure as possible. Our team has scientifically engineered new bond systems for coarse grinding (BXL9002) as well as fine grinding (BXL6550) of bumped wafers. In conjunction with the appropriate tape quality and the tape release mechanism, our wheels can grind the bumped wafers using existing set ups and similar process parameters as standard backgrind.