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the test pads and wafer fabrications
features into a subset of the wafer.
Blading enables a die loss and product
cost increase, but eliminates many
modules from the dicing streets.
Removing the modules creates a
clean area for cutting and loading that
improves problems associated with
mechanical dicing. There are other
complications that interact, such as
films used, and wire bond versus a
bumped device, but the major items
discussed here are the driving reasons
for mechanical dicing complications.

Packaging requirements and
interactions
Now that we have covered wafer fab
complications, let’s now move on to
Figure 3: Probe pad example. packaging requirements and interactions,
wafer dicing challenges associated with
package type, and finally, interaction
with scribe structures that need to be
considered during the design phase.
For example, if your device is for the
automotive market, you should consider
asking the following questions: Does it
have burn-in? Is the package prone to high
stress? Knowing your end customer’s
requirements and asking these questions
are normally considered during a design
phase review. However, many times parts
are multi-purposed and can be sold across
many different package types, families and
end user types. This situation complicates
the process further. Don’t panic if you are
Figure 4: Die size interaction to open streets.
a dicing engineer. The daily challenge
Driving improvements Another option is to utilize die of the job is to review in advance and
As die sizes shrink, improvements drop-in reticle shots. This is counter predict metal density capabilities, and then
in structure layout and placement can intuitive in the wafer fabrication area, adjust and work to solve complex dicing
enable improvements in dicing and as it incorporates complex techniques, challenges prior to them happening.
chipping. However, there is not one called blading, that increase mask Figure 5 shows a very challenging
rule—it’s all standard as technology, cost, and can impact one or the highest dicing situation. This is the output of a
metal layers, and device composition cost processes in a wafer fabrication new and challenging design type released.
will driver further complications on facility. Blading enables drop-in die Shown in the figure is a six metal layer
loading impact to mechanical dicing. that are designed to incorporate all of example of a dicing street structure with
Street width is a large factor in
the design process. Typically, streets
are designed to enable placement of
all necessary structures required for
alignment, test, and statistical process
control within the wafer fabrication
areas. If room on prohibited streets
are sometimes f itted with double
and triple scribes, metallization and
placements can be spaced out to
improve and lower density of dicing
street areas. In this manner, there is a
die per wafer loss and improvement in
dicing capability. Figure 5: Cross section of 6-metal layer device.

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