With the development of new technology in LED manufacturing, new processes for higher productivity (grinding vs lapping) are also evolving. Norton Winter FAVS™ grinding wheels are designed to grind material like Silicon Carbide, Sapphire, and other hard materials while achieving quality surface finishes, low sub surface damages, and high productivity.
In grinding these hard and brittle materials, one of the most important characteristics is the sub surface damage. The base material used for LED manufacturing tends to become "foggy" if sub surface cracks are allowed to remain. These cracks are usually a result of the mechanical processes carried out to slice or thin the wafers and reduce the wafer strength, causing low yields.
FAVS™ wheels are designed to eliminate these cracks and make the wafers strong. In order to achieve an acceptable productivity rate, the coarse wheel needs to be specially designed for free cutting action and self-dressing. This allows the wheel to be used without any conditioning during the lifetime.
FAVS™ wheels can be used to thin down sawn wafers (2", 3", 4") to the required size with finishes below 20 °A Ra. With the right combination of the coarse and fine specification for a particular machine tool, the LED substrate can be ground instead of lapped for the initial wafer preparation.
The same process can then be used for the backgrind operation after the devices are integrated on the substrate. Depending on the final finish required, the grind wheel specification can be altered.
Different materials that can be ground with this new type of bond system (XL040 for the coarse grind and XL073 for the fine grind).
We also offer a Cu free bond system - XL111 for the fine grind and XL112 for the coarse grind stations.
The following materials can be ground at an optimized cost of ownership and very good finish (Below 20 °A Ra):