Method for thinning and shipping ultra thin wafers on conventional tooling.
Original Publication Date: 2004-Dec-16
Included in the Prior Art Database: 2004-Dec-16
The need for ultra thin wirebond wafers (100 um and below) is becoming more common. The mounting, dicing and picking of the ultra thin wafer is a challenge.There are a few methods to achieve this process ,one is a quartz carrier wafer method and another total integration from grind to dicing. The invention allows for the thinning,shipping ,transport ,mounting, dicing , and picking of the wafers (100 um and below) on common existing toolsets.
Method for thinning and shipping ultra thin wafers on conventional tooling .
The method of the invention is as follows ,
1) Apply UV tape to the frontside of the wirebond wafer to be thinned.
2) Expose wafer with UV tape to UV energy source
3) Grind and polish wafers (slurry is in house mix 2 $ / liter vs 20 $ / liter )
4) Place wafers, with the UV tape, into coin stack for transportation to next operation or location.
5) Mount wafer on film frame for dicing (A) face up or (B) face down. (UV tape enhances the mounting process)
Steps post 5A) Detape wafers If wafers placed face up at step 5.
Final steps 5A) Dice and pick wafers
Steps post 5B) Using IR camera dice the wafers from the backside
5B) pick chip