Process Optimization
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IMPORTANT!
If there is too much friction on the wire during the reverse movement in the bonding tool, the wire can tear.
Therefore, the heights and travels (XYZ) must be set in such a way that friction is avoided as far as possible,
and the wire is bent during the reverse movement, but no other wire is pulled through the bonding tool (e.g.:
set reverse height lower than presign).
Reverse movement is possible, but it is not common to use wedge-wedge bonding.
Reverse motion is mainly used for very short loops (<250µm length).
Standard Loop at Ball-Wedge.
With the ball wedge the reverse movement plays an important role in forming the loop.
Therefore, <Use Reverse 1> or additionally <Use Reverse 2> should be activated for this bonding process.
TIP
In most cases it is sufficient to use a reverse movement.
In case a reverse movement is used to bend the wire slightly after about 30% of the loop length, <Use Reverse 1> can
be activated and the following parameters can be used:
When using the above parameters, a bend will be created after 1/3 of the loop, which will then form the highest point
of the loop.
However, if you program two reverse movements, <Use Reverse 1> can be used optionally to create an additional
defined bend just above the ball.
It is recommended not to use the movement and height in % but to change the units to µm.
In this case <Presign> has to be changed to µm as well.
The basic settings for a loop reverse movement would therefore be:
Presign
30%
Reverse Height
25%
Reverse Factor
5-20%
Loopheight
125%
Presign
30%
Turn Heigth
off
XY-Loopheight Factor
10%
Z-Delay
0%
Reverse Height
25%
Reverse Factor
30%
Presign
100µm
Reverse Height
60µm
Reverse Factor
60µm