Controlled Semiconductor offers two versions of our laser based wafer saw, the Wafer LS 304 and the Wafer LS Prejet. The LS 304 is our standard system for dry laser sawing, and the LS Prejet is our water-assisted laser sawing system. The advantages of laser sawing are reduced scribe streets, reduction in micro cracks, reduced breakage, and the elimination of costly saw blades. Typical semiconductor wafers have scribe streets in the 100um range. With the laser saw, the scribe streets can be reduced in size, giving wafer manufactures the ability to fit more die on a wafer, reducing the die cost. Scribe street cuts of 25um have been demonstrated.
Because of the ablation process that takes place with laser processing, the stress on the wafer is reduced, leading to a reduction in micro cracks. One of the industry trends is the move towards thinner and thinner die, and one of the major issues with processing these thinner wafers is breakage at the wafer saw operation. With the Wafer LS, this issue is eliminated because of the touchless laser sawing process. This technique is particularly useful in processing fragile GaAs wafers, which are brittle and have high breakage rates with the traditional saw process. With traditional wafer sawing techniques, one of the main costs is the consumable saw blades. The Wafer LS has no consumable parts, which leads to high manufacturing uptimes.