SIPLACE Vision Customer_en - 第127页
SIPLACE Vision - T eaching Fiducials What are Fiducials? S tudent Guide SIPLACE Vision (Customer) Edition 12/2008 EN SIPLACE Vision - T eaching Fiducials 127 6 SIPLACE V ision - T eaching Fiducials 6.1 What are Fiducials…
Component Shapes
Coplanarity Measurement for Gullwing and Ball Leads Coplanarity Measurement for IVP 3D Coplan
Student Guide SIPLACE Vision (Customer)
Component Shapes Edition 12/2008 EN
126
Differences to Lead Coplanarity
For this purpose, the CS Editor provides a 3D coplanarity tolerance value for editing (0.3 mm for 0.1 mm
solder paste thickness or similar) in the
Basic Handling
menu - when coplanarity measurement is active.
you can choose whether the measurement is to be repeated (
Do not reject if measurement fails
) if
incorrect measurement occurs (highly sensitive to focus height).
The ball height image shows areas without
measurement results (black) in the shadow of the
balls.
However, there are also reflections from
neighboring balls, which are shown as so-called
secondary reflections (red/yellow) or bright areas.
Direct reflections on the ball domes are a problem
for this sensor. If this problem occurs, you may
need to perform coplanarity measurement at a
different angle.
When soldering the balls of BGA components, an
additional "collapsing" of the hemispherical solder
balls can occur. This means that a ball might still
be soldered well even if it is outside the solder
paste height tolerance. The diagram on the right
shows this situation in which the component balls
collapse during soldering. The partial diagram on
the left shows the soldering state if the balls
remain stabile during a measured coplanarity
deviation.
The body of the BGA components could also
relax, meaning that the balls which are outside the
coplanarity tolerance would contact correctly
during reflow soldering.
SIPLACE Vision - Teaching Fiducials
What are Fiducials?
Student Guide SIPLACE Vision (Customer)
Edition 12/2008 EN SIPLACE Vision - Teaching Fiducials
127
6 SIPLACE Vision - Teaching Fiducials
6.1 What are Fiducials?
Fiducials consist of the following parts:
The optically recognizable structures which are used in the SIPLACE Vision system, for defining the
geometry, illumination and other programmable parameters and
The coordinate data.
These are made known to the SIPLACE Pro system, through the PCB programming.
Fiducials are optically recognizable geometric
structures which, as a rule, are not integrated into
the placement and/or electrical function of the
PCB. If no own fiducial structures are available,
contacts or other measuring points which remain
free of soldering paste can be used as fiducials.
Fiducials on a board (PCB) are used for the
following purposes:
PCB position recognition (for definition of the
placement position),
Good/bad board recognition (so-called inkspot
recognition) and
For accurate determination of the component
placement position.
SIPLACE Vision - Teaching Fiducials
What are Fiducials?
Student Guide SIPLACE Vision (Customer)
SIPLACE Vision - Teaching Fiducials Edition 12/2008 EN
128
The fiducial can only be trained, tested or used for placement, if the fiducial coordinates for the PCB are
known and have been sent to the machine.
Fiducials are approached in the following order during testing or placement:
PCB position recognition fiducials
Inkspot fiducials (global inkspot first; - also in bad case – and then the local inkspot fiducials of the
panels).
Component placement position fiducials.
If fiducials are trained, the operator determines the order of these fiducials through his selection. If the
position tolerance values are not set to maximum tolerance for all fiducials, the size of the tolerance field
will determine the order of PCB recognition fiducials. The fiducial with the greatest tolerance will be
approached first and that with the smallest tolerance will be approached last.
The SIPLACE Pro coordinate data includes:
The PCB/panel assignment
The fiducial position coordinates (X, Y)
The position tolerance data and
Use on the respective PCB (position
recognition fiducial; inkspot fiducial; placement
position fiducial).
It may also make sense to program more
fiducial coordinates and numbers and to
temporarily omit them when not needed.