Silicon Wafer Dicing A Look At The Process

Posted by leahgillam on June 3rd, 2013

Wafer dicing is the process through which the die is separated from a wafer of semi conductor once the wafer has been processed. The dicing process can be completed by scribing and breaking with the help of a mechanical saw or by laser cutting. This is the traditional method of completing the job in hand. However, modern day silicon wafer dicing process is something more than just separating silicon wafer into an individual die. With more packaging processes occurring at the wafer level a miniaturization is extremely necessary. It is also extremely important to make sure that silicon wafer at no stage should be thinned below 100UM or remain brittle. If so it does get brittle and resorts to chipping, cracking and starts to generate debris.

There are two methods as to how one can do the job. The first one is water scribing and the second is sawing. For the process to be smooth, one will require a diamond blade saw and a diamond scribe tool. Now irrespective of the silicon dicing process to be used, the process demands that the wafer be secure and once the dicing is over the die must remain intact through the die attach process.

The standard process of working is easy. The normal dicing process involves with the mounting of thinned wafers. The active side is definitely up. It releases tapes fixed to a steel ring. This is solely responsible for securing a wafer all throughout the dicing process. However, there are certain limitations in the whole process. The thinned wafers are a liability. At times, there may be a slight difficulty in removing the die after storage. Besides, one can always opt for a tape based singulation process. However, in the tape based system it is essential that one has a proper idea regarding the mounting systems. The type of tape used in the process must suit the materials getting diced.

The dicing tape is composed of three components. The first is a base film plastic. It is covered with a pressure sensitive adhesive film and a release film. There are two categories of tapes involved in the process. The first is a blue one and the second is UV. For silicon wafer dicing the blue ones are the most suitable. It is also a cheaper option. The adhesion level should be high enough to hold the die during sawing and low enough so that the die can be removed easily without further damage. If these things are taken care of then the process will be smooth.