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Modular Conveyor General Functions S tude nt Guide Advanced Level 2 SIPLACE D Series EN 05/2007 Modular Conveyor 10-1 10 Modular Conveyor 10.1 Functions 10.1.1 General In the Processing Area (PA1 or PA2), the PCB board w…
Component Handling
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Student Guide Advanced Level 2 SIPLACE D Series
Component Handling EN 05/2007
9-16
Modular Conveyor
General Functions
Student Guide Advanced Level 2 SIPLACE D Series
EN 05/2007 Modular Conveyor
10-1
10 Modular Conveyor
10.1 Functions
10.1.1 General
In the Processing Area (PA1 or PA2), the PCB board will be clamped from the bottom side against the
fixed holder on the conveyor system. Therefore, the space between the upper side of the board and the
placement head is independent of the board thickness and remains the same. This has the following
benefits:
The placement performance no longer depends on the board thickness.
Optimization of PCB fiducial centering:
The consistent space between the board upper edge and the PCB camera means that the PCB
camera is always optimally focussed on the upper side of the board. The PCB fiducial shape is
optimally imaged on the CCD chip of the PCB camera.
The PCB transport in the machine is configured so that the C&P12 head can place components up to a
maximum height of 6 mm.
The machine height can be set so that this machine can also be integrated into lines with transport
heights of 830, 900, 930 or 950 mm. Communication between the PCB conveyors of the different
machines is provided with the help of a SIEMENS interface or, as an option, via a SMEMA interface.
The transportation of the boards is monitored and controlled by light barriers, consisting of a transmitter
and a receiver module.
If the board has reached the placement area, the board is recognized by the light barrier and the
speed of the conveyor belt is reduced.
Approx.100ms later, a laser beam is used to recognize the front edge of the slowly moving board,
which is then stopped and clamped into place from below.
10.1.2 Clamping
The PCB is lifted for placement of components and pressed up against the PCB clamping rail. When the
lifting table rises the PCB and the complete conveyor drive unit is lifted up to the clamping position.
Therefore the placement level is constant and independent of the thickness of the PCB.
PCBs up to 368 mm long are clamped in the appropriate placement areas. Clamping does not take place
on the input and output conveyor. Boards with a length over 368 mm (option "long board": to 610 mm)
are kept in a clamped position on the conveyor belt up to a length of 360 mm (D1/D2: 440 mm) and are
then supported in the placement area only by the lifting table.
Modular Conveyor
Functions Width Adjustment
Student Guide Advanced Level 2 SIPLACE D Series
Modular Conveyor EN 05/2007
10-2
10.1.3 Width Adjustment
The width is adjusted by means of a motor as programmed. With the dual conveyor, different widths are
possible for the two conveyor tracks. The width adjustment uses a stepping motor, meaning that the new
PCB width can be set independently of other machine components.
The conveyor sides are fixed by means of a clamping unit on a steel strip.
The PCB width is adjusted via two adjustment units, installed under the input or output conveyors.
The stepping motor moves the two adjustment units synchronously through the use of ball screws
and a toothed belt.
To adjust the board width, the two adjustment units are positioned under the relevant conveyor side.
The precise position is detected by a BERO on the adjustment unit.
The conveyor side is mechanically connected to the adjustment unit by extending the pneumatically-
actuated fixing pins. This disables the clamping of the conveyor side (at the steel strip).
Once the new PCB width is reached the fixing pins of the adjustment unit are retracted once more.
The conveyor side is clamped again.
On the dual conveyor, the widths of the conveyor tracks have to be set one after the other (just one drive
for both conveyor tracks). The maximum and minimum PCB widths are protected by limit switches. If the
two conveyor sides of a conveyor lane are not parallel, this is automatically corrected during the width
adjustment. The two adjustment units are moved under the fixed conveyor side and the other conveyor
side is adjusted. Adjustment relates to the center point between the positions of the two adjustment units.
The adjustment unit which reaches its position under the flexible side first, locks the side. The process
continues until the second adjustment unit has reached its position and has also locked the flexible
conveyor side. The position of the conveyor side has now been recorded, fixed with the adjustment unit
and is ready to set the correct board width.
The flexible dual conveyor can also be used as a single conveyor by closing up track 2 (max. PCB format
368 x 380 mm).
10.1.4 Checking the PCB position on the conveyor sections
The positions of the PCBs is identified using light barriers (transmitter modules and receiver modules).
The transmitter light barriers are positioned below the transport belts. They are directed past the
transport belt to the opposite conveyor side to the receiver above the belt.
The signal from the light barriers stops PCBs in the input conveyors, intermediate conveyors and output
conveyors. These three light barriers can be assembled into four different positions to recognize also
"irregular" circuit boards (PCB with cutouts).
In the placement area, the light barrier triggers the deceleration or braking procedure via the DC
motors. A time period has already been set in the software for slow board approach towards the laser
light barrier.
A PCB moving control check the start- and arrival time at the conveyors. This is necessary because of
the PCB-information (bad mark -, PCB recognition) we transfer from PA1 to PA2. The operator is not
allowed to remove PCB’s from the intermediate conveyor.
10.1.5 Stopping the PCB
The PCB in the placement area is recognized by a laser light barrier. The laser beam looks for the front
edge of the board and stops it, as a result there is no shock against the stopper. The positioning accuracy
of the clamped PCB is +/-0.5 mm -precise enough for PCB recognition.