Figure 27.
The straight
120° I.C. angle capillary provides the sharpest transition from the I.C. to the hole. The
sharp edge that is created can cause considerable drag which can cause sagging or wavy
wire.
Figure 28.
The straight
90°I.C. angle capillary does not have as sharp at a transition as the straight 120° I.C.
angle style. This allows for less drag on the wire and therefore gives better looping.
Figure 29.
The 120°
double I.C. angle capillary consists of a 120° and 80° angle as shown above. The 80°
angle provides a smooth transition into the hole for improved looping. The 120° angle
produces strong tail bonds and higher ball shear strengths.
Figure 30.
The 90° double
I.C. angle capillary consists of 90° and 50° angles as shown above. The 50° I.C. angle
provides a smooth transition into the hold for good looping. The 90° angle forms a
taller, more compact ball bond and provides good tailing.
Figure 31.
The 120°
radiused inside chamfer design provides excellent looping characteristics and wire
control. This design is often preferred for high speed, low loop, long loop, and spider
leg applications.
Figure 32.
Most low loop
bonds, (0.006in./152µm) or less, are bonded with a capillary that has a radiused inside
chamfer. Using 0.001in./25µm wire, these loops are 0.0052in./132µm high and spanned an
average length of 0.138in./3.5mm.
(Photo
courtesy Shinkawa Corporation)
Figure 33. The fine pitch
(0.0045in./114µm) application pictured here has loops commonly called spider legs. Spider
leg loops vary in their shape and length as well as height depending on the application.
This 160 lead Quad Flat Pack has the die pads located 0.059in./1.5mm from the edge of the
die.
(Photo courtesy Shinkawa
Corporation)
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