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User Manual SIPLAC E HF Series 7 Station extensions Software Version SR.505.xx 05/2004 US Edition 7.8 PCB alignment 321 7.8 PCB alig nment 7.8. 1 General PCBs t o be proc essed some tim es have a le ngth to wid th rati o…

7 Station extensions User Manual SIPLACE HF Series

7.7 Multicolor PCB camera (type 18) 21 Software Version SR.505.xx 05/2004 US Edition

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– 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

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.

User Manual SIPLACE HF Series 7 Station extensions

Software Version SR.505.xx 05/2004 US Edition 7.8 PCB alignment

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7.8 PCB alignment

7.8.1 General

PCBs to be processed sometimes have a length to width ratio of 1:2 or worse. This means that

the shorter side of the PCB points in the direction of travel. During travel, such PCBs may twist

slightly and, as a result, the fiducials no longer lie within the PCB vision camera's search window.

In this case, the "PCB alignment" option ensures that these PCBs are realigned precisely at the

stopping position.

If PCBs with recesses in the direction of travel are processed, this may result in different process-

ing positions on machines with mechanical stoppers (HS-50, S-25 HM, F5 HM) and on machines

that monitor this position with laser light barriers (HF, HS-60, S-27 HM). The "PCB alignment" op-

tion ensures that the PCBs are stopped at the same position on all PCB conveyors. The "PCB

alignment" option is available for both single and dual conveyors.

Fig. 7.8 - 1 PCB alignment

(1)Lifting table

(2)PCB stop

7 Station extensions User Manual SIPLACE HF Series

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7.8.2 Description of the functions

The PCB is transported into the placement area until the laser light barrier triggers the stop signal

for the PCB conveyor. The lifting table with the PCB stops then moves up into a position in which

the PCB is not yet clamped and can still be moved by the conveyor belts. The two PCB stops are

level with the PCB, and the PCB supports (magnetic pins) are already in contact with the PCB.

The two conveyor belts move the PCB against the PCB stops and align them at the same time.

The lifting table then moves into its top end position, clamps the PCB and releases it from the PCB

stops so as not to affect the placement process. After the placement process, the lifting table and

PCB alignment are lowered and the PCB is moved on.