Packaging is often the final step in making a nanofabrication device functional as a stand-alone device or in the context of an intergrated system.
Nanofabricated devices are generally made in batches on wafers and need to be separated or packaged before use. This separation can be achieved through wet or dry dicing. In a wet dicing operation, a precision, high-speed, diamond impregnated blade is used to mill narrow grooves between the devices either partially or completely through the wafer.
During this process, water is circulated over the cutting surface to cool the blade and prevent the liberation of dangerous particulates into the air. Materials which would be damaged by water are diced using a dry process known as scribing. Scribing utilises a diamond tipped stylus which is drawn across the wafer surface creating lines of high-stress which are later broken over precision fulcrum.
After separation, the devices may need to be electrically connected to an interface via a process of gold or aluminium wire bonding.
Dicing and bonding are necessary for the completion of most nano and microfabrication devices.
The MCN houses two wafer dicing instruments - the Disco DAD321 automated dicing saw, for wet dicing processes, and the Dynatex DTX - Scriber/Breaker for dry processing. For bonding, MCN’s wire bonders are Kulicke & Soffa Wedge and Ball Bonders. They are used for both gold and aluminium bonding.
The MCN will soon also be home to a laser cutting system to be used in conjunction with the microwave plasma diamond CVD systems.
The laser cutting system will be capable of laser cutting for a wide range of materials, including diamond; laser micro-machining; and machining silicon structures on a micro-scale. It will also be useful the creation of MEMS devices.