Diamond sawing using diamond
blades is the preferred current process of wafer dicing nowadays. This
method evolved from diamond scribing and breaking which was the original
technique used for wafer dicing. Other methods include but are not limited to:
laser scribing and breaking, back etching, and slurry sawing.
Gila
Tools diamond blades feature circular steel discs with industrial diamonds
on its periphery, their edges bear one of three configurations: segmented,
continuous rim, or serrated. The blade cores are precision-made with slots that
provide faster cooling by allowing water or air to flow between the segments.
They are tensioned at the factory so that they always run straight at cutting
speeds, giving you smooth and precise cuts throughout. Our diamond saw blades
are engineered for strength and reliability and are designed to withstand hard
use to deliver optimal strength even when working on the harshest and most
abrasive materials.
The rationale for using diamond blades in wafer dicing over the
traditional scribing and breaking is that even with a well-maintained scribe
diamond, consistent 100% break out yield is not achievable. At least some
components will either be chipped or attached to sections of unwanted silicon.
Also, few breakouts are vertical, which makes scribing difficult for
automatic die bonding, especially if the pick up tool used has been designed to
make edge contact with the chip (a ‘collet’). Scribed dice also tend to ‘ride
over each other’ during handling, whereas with vertical edges, the chips stick
firmly against each other.
Lastly, scribing will not work effectively on dielectrically isolated
integrated circuits or anything made of amorphous or polycrystalline silicon,
which doesn’t fracture neatly.
A typical blade is a thin stainless steel disc, to the edge of which
fine diamond grit has been resin-bonded. The resultant saw (more properly, a
grinder) is able to cut slits in the silicon, which are only 70µm wide. The
once traditional method of scribe and break is now used only rarely for silicon
and is generally limited to brittle material such as gallium arsenide.
Wafer
dicing is the process by which die are separated from a wafer of
semiconductor following the processing of the wafer.
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