Although the use of lasers to scribe materials has been around for quite some time, the application of this process to dice semiconductor chips has been more difficult to implement. The process is even more difficult when devices are fabricated on hard substrate materials like sapphire, used in the semi-conductor industries.

There are a number of traditional methods in dicing sapphire wafers including dicing saw separation and scribe-and-break. However, these processes can waste valuable wafer area, costly, and have long process times.

At present, there are some advanced dicing wafer technologies that overcome the difficulties associated with the previous processes – laser scribing for sapphire is one example and it involves the following steps:

1. Protective coating preparation;
2. Mounting the wafer on a tape backing;
3. Wafer scribing with the laser;
4. Fracturing the wafer with a mechanical roller;
5. Protective coating cleaning.

Some recommendations to consider

Others provide insights for better cut quality and longer life in dicing sapphire. Some of these are the following:

1. Start with vitrified bond blade;
2. Start  a fairly aggressive grit size 50-60 microns and tune down from there if applicable;
3. Larger grit allows you to run at slightly higher feed speed – about 0.080” per second.

Others also use a resin bonded blade in dicing sapphire for some important reasons:

• Because sapphire is so hard;
• Resin generate less heat

Additional tips in dicing sapphire wafer

1. Use a thinner blade if the sapphire is thin.
2. Slower cut speed, thicker blade, and larger grit size for thicker sapphire.
3. When mounting on tape, use something that is thick and has a high adhesion; waxing may also be an option.