X-Serie S_705.pdf - 第46页
46 Digital SIPLACE Vision system Checking the component quality Overview of key functions Checking the lead length The lead length check determin es whet her the leads have be en dist orted. This inspection is p ossible …
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Digital SIPLACE Vision system
Checking the component quality
Overview of key functions
Recognizing the collinearity of components
Damaged or bent leads are recognized. This helps avoid solder-free connections during the subsequent solder-
ing process.
Damaged leads Damaged leads
Recognizing flipped (face down) or upright components
Both chip and IC component shapes (e.g. SOT) recognized in flipped (turned face down) or upright state.
SOT OK SOT “face down”
Flipped chip Chip upright
Checking the lead width
The optical checking of the lead width recognizes tilted or damaged leads. This helps to recognize e.g. diodes
with tilted leads.
Lead width OK Tilted lead
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Digital SIPLACE Vision system
Checking the component quality
Overview of key functions
Checking the lead length
The lead length check determines whether the leads have been distorted. This inspection is possible by checking
whether leads of the same type e.g. chip shapes have different lengths. Flipped and rotated components can also
be detected.
Component OK in this position Rotated
Detecting special shapes with rectangular functions
When using certain special component shapes, it is sometimes necessary to program parts on the components or
outlines as rectangular shapes. This ensures that they can be processed more reliably.
Rectangular function on the component Rectangular component with irregular edges
Detecting incorrect component descriptions
The Vision system checks whether the position of the component corresponds to the measured Vision data. The
following example has more leads than were programmed in the component shape description.
Teaching complex BGA structures
Complex BGA structures can be taught within only a few seconds.
Placing when inkspot is not present
A fiducial can now be defined for the omission of panels. If a fiducial is found (cross, circle, etc.), this panel will be
omitted.
Checking the inner area of circular fiducials
To differentiate circular fiducials from other structures on the board, a brightness check is performed in the inner
area of these fiducials.
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Vision sensor technology
PCB position recognition
Description
The optimum fiducial shapes
vary according to the condi-
tion of the surface. When
using bare copper surfaces
with low oxidation, it is advis-
able to take the single cross,
as the high amount of infor-
mation provided helps
achieve the greatest
accuracy. Rectangle, square
and circle are less "informa-
tive" but save space and can
even be used when oxidation
is at an advanced stage. Cir-
cle or square are advisable
for tin-plated structures as
the ratio of the fiducial
dimensions to the presolder
thickness is particularly
favorable.
Fiducial criteria
Locate 2 fiducials
Locate 3 fiducials
X-/Y-position, rotation angle, mean PCB distortion
additional: shearing, distortion separately in X and Y direc-
tion
Fiducial shapes Synthetic fiducials: circle, cross, square, rectangle, dia-
mond, circular, square and rectangular contours, double
cross, pattern: any
Fiducial surface
Copper
Tin
Without oxidation and solder resist
Warpage of fiducial 1/10 of structure width, both with good
contrast to environment
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
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 diamond 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 all fiducial shapes 3 mm
Max. bar width for cross/double-cross 1.5 mm
Minimum tolerances generally 2% of nominal dimension
Max. tolerances generally 20% of nominal dimension