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7 Vision Systems S IPLACE 80S/F/G User’s Manual 7.3 Component Vision System Edition 07/97 from Software Version SR.010.xx 7 - 22 Line engine er Screen : RGB mo nitor (VGA mode) 640 x 484 pixels Component s izes: 1 mm x 0…
SIPLACE 80S/F/G User’s Manual 7 Vision Systems
Edition 07/97 from Software Version SR.010.xx 7.3 Component Vision System
Line engineer 7 - 21
7.3 Component Vision System
The component vision system records the precise position of a component by determining on the one hand
the offset of the component center relative to the axis of symmetry of the nozzle, and on the other hand the
rotation angle offset to the relative rotational position of the nozzle. The condition analysis of the lead configu-
ration in both x and y direction is also possible.
7.3.1 Component Vision System of the SIPLACE 80S Placement Sys-
tem
7.3.1.1 System Description
The component vision system consists of:
●
the optical system for recognizing the position of components
Each revolver head has its own component position recognition system in star station 8 (see Fig. 7.1.2).
●
the vision evaluation unit
For each gantry two evaluation units are accommodated in the control unit, one for PCB and one for com-
ponent position recognition (see Fig. 7.1.3).
A CCD camera with deflection mirror, imaging lens and LED lighting system constitutes the optical position
recognition system. The usable field of view of the CCD camera (SONY camera XC75) amounts to 14 mm x
18 mm. For position recognition or for the lead tests, the component is evenly illuminated by the LED rows
using the incident-light illumination method, and using the lens sharply imaged on the CCD chip. Using digital
image processing, the correlation principle, and the HALE process (High Accuracy Lead Extraction) it is pos-
sible to determine the parameters for position, angle of rotation and lead condition.
The vision evaluation unit (MVS) has already been described above in Section 7.2.1, as it handles both func-
tions of PCB and component evaluation.
7.3.1.2 Technical Data
Camera type: SONY XC75
Number of pixels: camera 768 (H) x 494 (V)
image 640 (H) x 484 (V)
Field of view: 19 mm x 25 mm
Lighting method: incident-light illumination (red light)
Image processing: correlation principle, HALE - grey-scale procedure
(High Accuracy Lead Extraction)
Evaluation time with lead test: ca. 230 msec (PLCC18)
ca. 140 msec with small components
7 Vision Systems SIPLACE 80S/F/G User’s Manual
7.3 Component Vision System Edition 07/97 from Software Version SR.010.xx
7 - 22 Line engineer
Screen: RGB monitor (VGA mode) 640 x 484 pixels
Component sizes: 1 mm x 0.5 mm ... 18 mm x 14 mm
Range of recognizable components: TSOP, LCC, PLCC, QFP, SO series and so on
basically all components with J and gullwing leads
Minimum lead spacing: 0.5 mm
Number of package forms:
≤
2047
7.3.1.3 Description of Function
One segment of the placement head picks up a component at star station 1. As the revolving star advances,
further components are picked up. Star station 8 accommodates the optical unit of the component vision sys-
tem. On its arrival the component is evenly illuminated with red light by staggered rows of LED's. The lens cre-
ates sharp imaging of components up to a height of 5 mm on the CCD chip of the camera.
The digital imaging of the component created by the component camera is transmitted to the vision evaluation
unit. Using digital image processing (HALE procedure) the evaluation unit compares the component image
with an artificial model previously created with the GF editor (GF= package form). The parameters obtained
from this provide information on positional deviations, rotational angle, lead condition, and component reiden-
tification. The HALE procedure has proved to be highly resistant to interference factors such as interference
reflections, the differing reflection characteristics of lead, incidental light influences, and so on. Once mea-
surement has been successfully completed the segment rotates the component in star station 9 in the correct
placement direction. In star station 1 the component is then placed correctly oriented onto the circuit board.
7.3.2 Component Vision System in the SIPLACE 80 F Placement
Systems
7.3.2.1 System Description
The component vision system consists of
●
the optical system for recognizing the position of components.
The revolver head is equipped with a component position recognition system in star station 8
(see Fig. 7.1.2).
Up to two component vision systems can be used for the IC placement head. These are mounted perma-
nently on the machine base (see Fig. 7.1.5). One (vision system) is used for the optical centering of con-
ventional components with leads. The other - with a FC sensor - optically centers flip chips (see Section
7.6.3.4 Option “Measure component”).
●
the vision evaluation unit
The vision evaluation unit for both PCB and component position recognition is accommodated in the con-
trol unit (see Fig. 7.1.6).
SIPLACE 80S/F/G User’s Manual 7 Vision Systems
Edition 07/97 from Software Version SR.010.xx 7.3 Component Vision System
Line engineer 7 - 23
Component Position Recognition System of the Revolver Placement Head
The revolver placement head's optical system for component position recognition has already been described
in Section 7.3.1.
Component Position Recognition System for the IC Head with IC Sensor
All components of the optical system
–
CCD camera (SONY XC77 camera)
–
lens
–
optical band filter for suppression of unwanted reflections
are accommodated in a dustproof case. The useful field coverage of the CCD camera amounts to 38 mm x 38
mm. For position recognition or for testing leads the IC module is illuminated by three rows of LEDs using the
reflected light method and its image sharply reproduced using the lens on the CCD chip. Digital image pro-
cessing procedures are used to determine parameters for position, rotation angle and condition of leads of
fine-pitch components and BGAs (ball grid arrays).
Component Position Recognition System for the IC Head with FC Sensor
All of the optical components of the system, such as
–
CCD camera (SONY XC75C camera) and
–
lens,
are accommodated in a dustproof case. The visual field of the CCD camera is 12.2 mm x 9.2 mm. For position
recognition or the Ball test the flip chips are illuminated by two rows of LEDs using the reflected light method
and their image sharply reproduced using the lens on the CCD chip. Using digital image processing methods,
the parameters are determined for position, skew of the component and the number and position of the balls.
The vision evaluation unit is described in Section 7.2.1.
7.3.2.2 Technical Data
Position Recognition System for the IC Head for components with lead connections
Camera type: SONY XC77
Number of pixels: camera 768 (H) x 494 (V)
image 640 (H) x 484 (V)
Field of view: 38 mm x 38 mm
Lighting method: incident-light illumination (red light)
three levels of illumination
Image processing: HALE - grey-scale procedure (High Accuracy Lead
Extraction) with small components approx. 140 msec
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 spacing: 0.4 mm
Number of package forms:
≤
2047