Investigation of Dicing Saw Methods Impacting Back-End Assembly Process

The chip size, substrate material and package type of ICs are continuously changed due to the advanced process development. In order to satisfy these needs, it is necessary to cut wafers as discrete chip shape. Recently, the cutting technology cardinally relies on the thinner diamond blade plus some variable dicing saw parameters to obtain the separate chips. Although the cutting process is similar to that with traditional mechanical cutting, the accuracy and the quality are totally different. The previous is better than the last. Therefore, the cutting cost is not easily reduced more, except promoting the cutting yield. At the same time, if the utility rate of the cutting machine in one day is increased, this is an alternative to possibly decrease the cost. In present and commercial species of cutting machine, there are single cut, double cut, and laser cut. Except some advanced products or special wafers with laser cut method, most of commercial ICs are still cut with single-cut machine. In this study, we investigate the recent wafer cutting methods and how to protect the pad quality on ICs and probably decrease the assembly price. During this effort, we expect that one is to increase the cutting yield and the other is to practically reduce the assembly-line cost.