Specification SIPLACE X-Series规格说明书2.pdf - 第36页
36 Vision Sensor Technology PCB Position Recognition Description Different fiducial shapes prove to be optim al depend- ing on the condition of the surface. Particularly advis- able for bare copp er surfaces with little …
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Digital SIPLACE Vision System
Checking the Component Quality
Overview of the Most Important Functions
Checking the lead length
The lead length check detects whether the lead is twisted.
This can occur with chip models, for example, due to the different lengths of the two leads.
Flipped and rotated components are also detected.
Component in this position is OK Rotated
Detecting special models with rectangular functions
With certain special models, parts on the component or outer contour have to be
programmed as rectangular models so that they can be processed more reliably.
Rectangular function on the component Rectangular component with non-uniform boundaries
Detecting incorrect component descriptions
The vision system checks whether the position of the component agrees with the measured vision data. In the
following example there are actually more leads than were programmed in the package form description.
Teaching complex BGA structures
Complex BGA structure can be taught within a few seconds.
Placing when there is no ink spot
It is now possible to define a fiducial for omitting subpanels.
If a fiducial (cross, circle, etc.) is found, this subpanel will be omitted.
Checking the inner area of circular fiducials
To make circular fiducials easier to distinguish from other structures on the PCB,
a brightness check is carried out in the inner area of these fiducials.
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Vision Sensor Technology
PCB Position Recognition
Description
Different fiducial shapes
prove to be optimal depend-
ing on the condition of the
surface. Particularly advis-
able for bare copper surfaces
with little oxidation is the sin-
gle cross. Maximum accu-
racy is achieved due to the
high information content.
Rectangle, square and circle
are less “informative” but
save space and can even be
used when oxidation is at an
advanced stage. Advisable
for tinned structures are
circle or square because in
this case the ratio of the fidu-
cial dimensions to the presol-
der thickness is particularly
favorable.
Fiducial criteria
Locate 2 fiducials
Locate 3 fiducials
X-/Y-position, rotation angle, mean PCB distortion
in addition: shear, distortion in X- and Y-direction separately
Fiducial shapes Synthetic fiducials: circle, cross, square, rectangle, rhombus, circu-
lar, square, and rectangular contours, double cross, any pattern
Fiducial surface:
copper
tin
Without oxidation and solder resist
Fiducial warp 1/10 of structure width, both with good contrast to
environment
Dimensions of synthetic fiducials
min. X/Y size for circle and rectangle: 0.25 mm
min. X/Y size for annulus and rectangle: 0.3 mm
min. X/Y size for cross: 0.3 mm
min. X/Y size for double-cross: 0.5 mm
min. X/Y size for lozenge: 0.35 mm
min. frame width for annulus and rectangle: 0.1 mm
min. bar width / bar distance for cross, double-cross: 0.1 mm
max. X/Y size for fiducial shapes: 3 mm
max. bar width for cross / double-cross: 1.5 mm
min. tolerances, general: 2% of nominal dimension
max. tolerances, general: 20% of nominal dimension
Dimensions of patterns
min. size
max. size
0.5 mm
3 mm
Fiducial environment Clearance around reference fiducial not necessary if there is no
similar fiducial structure in the search area
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Vision Sensor Technology
PCB Position Recognition
Bad Board Recognition
Ink Spot Criteria
Methods
• Synthetic fiducial recognition method
• Mean grayscale value
• Histogram method
• Template matching
Shapes and sizes of fiducials/structures for
synthetic fiducials
other methods
For dimensions of synthetic fiducials, see page 36
min. 0.3 mm
max. 5 mm
Masking material good coverage
Recognition time depends on the method: 20 ms - 200 ms
Description
In the cluster technology
each subpanel is assigned
an ink spot. If this is present
during the measurement via
the PCB vision module, the
corresponding subpanel is
populated. With this function
it is possible to eliminate
costs due to unnecessary
population of faulty sub-
panels.
Technical data for PCB position detection
PCB fiducials
Local fiducials
Library memory for recognition of
bad panels
up to 3 (subpanels and multiple panels)
up to 6 for the Long board option (optional PCB fiducials are out-
put before optimization.)
up to 2 per PCB (may be of different types)
up to 255 fiducial types per subpanel
Image analysis Edge detection method (Singular feature) based on grayscale
values
Lighting method Front lighting
Fiducial recognition time 0.1 s
Field of vision 5.78 x 5.78 mm