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SIPLACE 80S -20/F4 User Manual 6 Vision functions Software version SR.407.xx 01/2001 US Edition 6.3 Component vision systems 231 els using the front lig hting meth od, and are proj ected ont o the CCD ch ip in sharp foc …
6 Vision functions SIPLACE 80S-20/F4 User Manual
6.3 Component vision systems Software version SR.407.xx 01/2001 US Edition
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6.3.1.3 Functional description
A segment of the 12-segment Collect&Place head picks up a component at star station 1. As the
star advances, further components are picked up. Once a component reaches star station 7,
where the component vision system is located, three offset rows of LEDs evenly illuminate the
component with infrared light. The lens maps components up to 5mm high in sharp focus onto the
camera’s CCD chip. 6
The digital image of the component generated by the camera is then transferred to the vision anal-
ysis unit, where the HALE digital image processing method is used to compare the component
image with a synthetic model previously created in the GF (package form) editor. The parameters
thus obtained provide information on deviations in position, the rotational angle, lead condition,
and component reidentification. The HALE method has proved to be highly resistant to disruptive
factors such as unwanted reflection, different reflection behavior of leads, diffused light, etc, and
it is faster and more accurate than the matching method.Once the measurement is complete, the
segment advances to star station 9, and rotates the component into the correct orientation for
placement. Finally, the component is placed in the correct position on the PCB at star station 1.6
6.3.2 Component camera module for the Pick&Place head
6.3.2.1 System description
Component vision module for the Pick&Place head: fine pitch vision module 6
All the optical components of the system 6
– CCD camera (SONY XC77 camera)
– lens
– optical strip filter for suppressing unwanted reflections
are located in a dust-tight housing. The field of view of the CCD camera measures 38 mm x
38 mm. For position recognition, and for the lead test, the component is illuminated by three LED
levels using the front lighting method, and is projected onto the CCD chip in sharp focus by the
lens. The position, rotational angle, and lead condition parameters are determined for fine pitch
components and BGAs (Ball Grid Arrays) using digital image processing methods. 6
Component vision module for the Pick&Place head: flip-chip vision module 6
All the optical components of the system, such as the 6
– CCD camera (SONY XC75C camera)
– lens
are located in a dust-tight housing. The field of view of the CCD camera measures 12.2 mm x
9.2 mm. For position recognition and for the ball test, the flip-chips are illuminated by two LED lev-
SIPLACE 80S-20/F4 User Manual 6 Vision functions
Software version SR.407.xx 01/2001 US Edition 6.3 Component vision systems
231
els using the front lighting method, and are projected onto the CCD chip in sharp focus by the lens.
The position, rotational angle parameters, and the number and position of the balls are determined
using digital image processing methods. 6
The vision analysis unit is described in section 6.1.4
, from page 218. 6
6.3.2.2 Technical data
Fine pitch vision module for the Pick&Place head 6
Camera type: SONY XC77
Number of pixels: 484 x 484
Field of view: 38 mm x 38 mm
Illumination method: Front lighting (infrared light)
3 illumination levels
Image processing: HALE gray scale method
(H
igh Accuracy Lead Extraction)
Screen: RGB monitor (VGA mode), 640 x 484 pixels
Range of recognizable components: Fine pitch up to 55 mm x 55 mm and BGAs
(ball grid arrays)
Minimum lead pitch: 0.4 mm
Flip-chip vision module for the Pick&Place head 6
Camera type: SONY XC75C
Number of pixels: 484 x 484
Field of view: 12.2 mm x 9.2 mm
Illumination method: Front lighting (infrared light)
2 illumination levels
Image processing: approx. 1 second for standard flip-chips
Screen: RGB monitor (VGA mode), 640 x 484 pixels
Range of recognizable components: flip-chips and fine pitch components up to 15 mm x
15 mm
Minimum ball size: 80 µm
Minimum lead pitch: 0.2 mm
6.3.2.3 Functional description
There are two optical centering systems available for centering components with the Pick&Place
head: 6
– the fine pitch vision module for fine pitch components up to 55 mm x 55 mm in size, and with
a minimum lead pitch of 0.4 mm, and BGAs (ball grid arrays)
– the flip-chip vision module for flip-chips and fine pitch components up to 15 mm x 15 mm in
size, and with a minimum lead pitch of 0.2 mm
6 Vision functions SIPLACE 80S-20/F4 User Manual
6.3 Component vision systems Software version SR.407.xx 01/2001 US Edition
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The Pick&Place head picks up components from waffle pack trays, and positions them over the
optical centering system used. Offset rows of LEDs evenly illuminate the component with infrared
light. The digital image of the component generated by the camera is then transferred to the vision
analysis unit, where it is evaluated according to the component type. The results thus obtained
provide information on deviations in position, the rotational angle, lead condition, and the mapping
quality of the component. 6
New illumination methods and special algorithms for obtaining the component parameters have
been developed for BGAs and flip-chips. This means that this new generation of components
can now be optically centered.
The Pick&Place head returns any components that cannot be optically centered to the waffle
pack tray for further analysis.
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6
6
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6.3.3 Criteria for Recognition of Components
Shape of the components 6
Optical component centering allows both regular and irregular components to be centered. The
maximum number of leads, horizontally and vertically, is 99 in each case. 6
Criteria for regular components 6
Definition:
A component is deemed to be regular when it satisfies the following four conditions: 6
– rectangular package shapes (special case: square shape)
– only one lead type per side
– only one lead group per side
– opposite lead groups located symmetrically with respect to the two main axes
(X and Y axes).