Silicon wafers, which are thin slivers of silicon created in a lab setting, are diced using a diamond saw to divide them into individual units. While other methods may be used, diamond dicing holds advantages over these methods. After a wafer has been diced, the components can be used in integrated circuits and semiconductors, which are used to make all different kinds of electronic equipment and devices, from cell phones to cars to sophisticated medical equipment.
Separating the Dice
As dice are separated, the blade crushes through the silicon and simultaneously removes the debris that is being created during the processing. The material is carefully removed along predefined “streets” that are inactive portions of the silicon which have been marked during the etching process. A nickel bonded diamond blade is generally used to dice through silicon.
Feed Rate during Dicing
During the dicing process, the blade turns between 30,000 and 60,000 rpm. The feed rate, or the speed at which the blade moves along the silicon, determines the throughput (the number of wafers diced per hour.) While a high throughput is desirable, higher feed rate speeds may cause silicon to chip and may affect the accuracy of the cuts. It is important to optimize the feed rate so that the throughput is as high as it can possibly be without sacrificing product quality.
The way that the wafer is secured during the diamond dicing process may have a huge impact on how easy it is to proceed with the rest of processing. Wafer securing may also affect whether or not the wafer is damaged during processing.
Wafers are often mounted to release tape, but it can be difficult to remove die after processing and tape may become cut or damaged, affecting the security of the die. Using a jig based system that relies on vacuum pressure may be preferable, as die will easily release after processing. Wax on glass may also be used to secure die, eliminating movement during dicing and processing.
After silicon wafers have been diced and residue has been removed using a specialized pressure washer, dice are carefully packaged in chip trays or Gel-Paks as specified by customers. Gel-Paks immobilize components so that die do not become damaged during storage or transportation. After arrival at the location of choice, die can be easily removed from the packaging for safe and convenient use in many different applications.