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6 Vision functions SIPLA CE 80S-20/F4 User Manual 6.3 Component v ision systems Sof tware version SR.407.xx 01/2001 US Edition 230 6.3.1.3 Functional descript ion A segmen t of th e 12-segme nt C ollect& Place head p…

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SIPLACE 80S-20/F4 User Manual 6 Vision functions
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229
6.3 Component vision systems
The PCB vision system records the precise position of a component by determining the offset be-
tween the component center and the nozzle’s axis of symmetry, and by calculating the rotational
offset from the relative rotational position of the nozzle. It is also possible to analyze the state of
the lead configuration in the X and Y directions. The component vision system consists of the op-
tical system for recognizing the component position, and the vision analysis unit. 6
6.3.1 Component vision system on the 12-segment Collect&Place head
6.3.1.1 System description
The 12-segment Collect&Place head has its own component position recognition system in star
station 7 (see Fig. 6.1 - 3
, page 214). The vision analysis unit for PCB and component position
recognition is located in the control unit (see Fig. 6.1 - 6
, page 219). 6
The optical component position recognition system consists of a CCD camera with deflector, im-
age lens, and LED illumination system. The usable field of view of the CCD camera (SONY XC75
camera) measures 24 mm x 24 mm. For position recognition, and for the lead test, the component
is evenly illuminated by the rows of LEDs 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 using the h
igh-accuracy lead extraction (HALE) method of digital image process-
ing. 6
The vision analysis unit (MVS) was described in section 6.1.4
, page 218, since it performs both
PCB and component evaluation functions. 6
6.3.1.2 Technical data
Camera type: SONY XC75
Number of pixels: 484 x 484
Field of view: 24mm x 24mm
Illumination method: Front lighting (infrared light), 3 LED levels
Image processing: HALE gray scale method
(H
igh Accuracy Lead Extraction)
Screen: RGB monitor (VGA mode), 640 x 484 pixels
Component sizes: 0.5mm x 0.5mm ... 18.7mm x 18.7mm
Range of recognizable components: TSOP, LCC, PLCC, QFP, SO series up to SO28
essentially all components with J and
gull wing leads,
µ
BGAs
Minimum lead pitch: 0.3mm for the camera
0.5mm for the machine
Minimum ball diameter for
µ BGAs
:250µm
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