DEK INFINITY USER MANUAL - 第244页
INFINIT Y ',163(&7,21 02'8/(29( 59,(: 8.4 User Manual Software Version 7 Stenci l Inspe ction The various stencil inspections are shown below . (Histogram information is detailed on this page.) Histogram…
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Software Version 7 User Manual 8.3
There is no provision to select sites to be pre-imaged individually. All sites are
pre-imaged once (one) or every cycle (every).
NOTE
A new batch may be started when the machine is switched ON/OFF or a product
file being re-loaded.
Light Calibration The stencil image is captured once only, (as this does not change throughout the
printing process). When the first board enters the machine, the camera visits all
sites and stores the size and shape of the apertures. This is a one time operation,
therefore the stencil must be clean.
Board Inspection The various board inspections are shown below.
NOTE
Uneven tinning of the board and/or misaligned solder mask may be seen as
paste, which could cause false readings. DEK’s Green camera and lighting
setup can eliminate this effect.
The pad on a selected board site is
learnt as a reference for comparison
with inspected sites.
Since the area of the pad is learnt,
and the area of paste can be
recognized, any change in pad area
must be paste. Hence the area of
paste present can be calculated with
respect to the aperture size.
The centre of the paste is compared
to the centre of the pad to produce
alignment error information in X and Y.
Since the area of paste can be
recognized, the distance between
two areas of paste (bridging) can
be calculated.
Pad
Board
Paste
Clean Board
Paste Present (Basic)
Alignment (Advanced)
Bridging (Advanced)
X
Bridging Distance
Y
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8.4 User Manual Software Version 7
Stencil Inspection The various stencil inspections are shown below. (Histogram information is
detailed on this page.)
Histogram The vision card analyses the grey scale levels of the pixels that make up the site
image. From this information a histogram is produced, this can be used as a
visual aid to setting up lighting for 2D inspection.
Any change to the area of the
stencil must be paste, hence the
area of smear can be calculated.
This is relative to the area of
white lost in the histogram.
Smear (Advanced)
The position and area of
apertures within the stencil site
are learnt as a reference.
Aperture
Stencil
Clean Screen
Histogram
Any change to the area of the
aperture must be paste, hence
the percentage of blockage can
be calculated. This is relative to
the area of black lost in the
histogram.
Blockage (Basic)
Paste
Paste
Stencil Histogram
Black
StencilAperture
Paste
White
Grey Scale Level
Board Histogram
Number
of
Pixels
Number
of
Pixels
Black
PadBoard
Paste
White
Grey Scale Level
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Software Version 7 User Manual 8.5
Paste Volume
Prediction
The volume of paste on a pad can be predicted using both 2Di blockage and paste
on pad inspection results. This is only available whilst the level of inspection is
set to Advanced for both board and stencil. An example of how paste volume
prediction is achieved is shown in the graphic below.
In the example shown the aperture is 100% clear. The paste on pad value was 100%.
This can be represented by the following model of the printed paste :
This is represented by the following model of the printed paste :
Top face equals area of
aperture not blocked by
paste, ie 100%.
Top face equals area of
aperture not blocked by
paste, ie 60%.
Bottom face equals area of
paste on pad, ie 100%.
Bottom face equals area of
paste on pad, ie 90%.
Using a complex formula 2Di predicts the volume of paste, in this case 74%
Aperture
From this information the system predicts the volume of paste, in this case 100%.
In the following example the aperture has a blockage of 40%. Therefore the aperture is
60% clear. The 60% is equal to a rectangle of the same size as shown below. The paste
on pad inspection result is 90%.
Stencil
Pad Paste on Pad
Board
AperturePaste (Blockage) 40%
Stencil
AperturePaste (Blockage) 40%
Stencil
Equals
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