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User Manual SIPLAC E HS-60 7 Station extensions Software version SR.503.xx 07/2003 US Edition 7.5 Ceramic substrate centering 171 7.5.5 Optical centering wit h the multi-c olor PCB camera 7.5.5.1 General As an op tion, a…
7 Station extensions User Manual SIPLACE HS-60
7.5 Ceramic substrate centering Software version SR.503.xx 07/2003 US Edition
170
7.5.4.2 Fiducial structure
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Recommendation 1
Fiducial structure Black resistive paste as the background.
Conductive paste printed on it as the fiducial.
Recommendation Background 0.75 mm larger than the fiducial on all sides.
Method of illumination Normal light
Advantage Good contrast; good sharpness;
Reference Circuit-board conductor layer
Assessment This combination gives the best results. Highly recommended.
Recommendation 2
Fiducial structure Fiducial made from circuit-board conductor material, e.g. 6119, and
overprinted with passivated glass 4330.
Method of illumination Oblique light
Advantage No additional steps required
Reference Circuit-board conductor layer
Assessment Fiducials are less sharp than for recommendation 1. Recommended.
Recommendation 3
Fiducial structure Fiducials made from circuit-board conductor layer against a free ceramic
background.
Method of illumination Oblique or normal light (depending on the paste)
Advantage No additional steps required
Reference Circuit-board conductor layer
Note Fiducials are less sharp than for recommendation 2.
The fiducial image depends on the surrounding free surface. It may be
necessary to teach every circuit separately.
Assessment Recommended under certain conditions.
User Manual SIPLACE HS-60 7 Station extensions
Software version SR.503.xx 07/2003 US Edition 7.5 Ceramic substrate centering
171
7.5.5 Optical centering with the multi-color PCB camera
7.5.5.1 General
As an option, a multicolor PCB camera can be installed in place of the sub-gantry camera. The
multicolor PCB camera offers four different types of illumination. This greatly increases fiducial de-
tection and thus the centering accuracy.
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Fig. 7.5 - 3 Multi-color PCB camera
7.5.5.2 Types of illumination for the multicolor PCB camera
The following types of illumination can be selected on the multicolor PCB camera:
– Standard lighting
This mixture of white and infrared lighting can be used to detect a broad range of fiducials. The
image contrast can be improved by varying the illumination, thus optimizing the centering of
different fiducials.
– White lighting
This type of illumination is used for standard PCBs with tinned fiducials.
– Blue oblique lighting
In most cases, this can be used to greatly improve the contrast with bright fiducials on a light
7 Station extensions User Manual SIPLACE HS-60
7.5 Ceramic substrate centering Software version SR.503.xx 07/2003 US Edition
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base material, such as ceramic or CEM. Fiducials covered with solder resist can also be de-
tected better on a light background.
– Infrared lighting
This type of illumination is particularly useful for fiducials that are covered with solder resist or
for fiducials on flex materials. It is also sometimes possible to improve detection of silver/plat-
inum fiducials on ceramic. This should be tested by carrying out a test centering or placement
run.