00196044-05 - sg x und x4i fse_en.pdf - 第263页

C&P20A Board Recognition - Centering the Board Fiduc ials Pickup and Placement Cycle for C&P20A S tudent Guide (FSE) SIPL ACE X Series and X4I Edition 01/2009 EN C&P20A 263 7.4.4 Board Recognition - Ce nterin…

C&P20A

Pickup and Placement Cycle for C&P20A Board Position Recognition

Student Guide (FSE) SIPLACE X Series and X4I

C&P20A Edition 01/2009 EN

262

7.4.3 Board Position Recognition

We differentiate between standard position recognition and dual position recognition.

PCB – position recognition (standard position recognition)

Board position recognition is used to determine the exact position of the board in the machine (conveyor

--> placement area).

PCB position recognition is performed with gantry 4 for placement area 1 and with gantry 2 in placement

area 2.

There should be at least two fiducials on each PCB. These are then used to calculated the X/Y position

and the rotary angle of the board, in the conveyor system.

The fiducials should not be on the same line as one another.

Up to 3 fiducials can be programmed for position recognition. With the third fiducial you can also

determine and correct any displacement within the board (shrinkage, stretched).

Dual position recognition (for alternating mode only)

Dual position recognition is required in order to guarantee the placement accuracy. Materials change

according to the temperature they are subjected to and the same applies to the machine gantries.

Dual position recognition is performed with gantry 1 in placement area 1 and with gantry 3 in placement

area 2.

In the case of dual position recognition, gantry 1/3 uses the fiducial position recognition values from

gantry 2/4 to calculate the placement offset for gantry 1/3. Depending on the arrangement of fiducials on

the board, either 2 or 3 fiducials will be used for dual position recognition.

The fiducials for dual position recognition are selected so that the calculation performed can be as

accurate as possible.

Temperature compensation

A further measure to ensure placement accuracy is the temperature compensation with the help of

sensors on the head plate. The head plate features two temperature sensors, the temperature values of

which are regularly checked via a separate bus system.

The software uses these temperature values to calculate an offset value, which is added to the head

offset.

 Head offset SW 60x is the distance PCB <--> component camera

 Head offset SW 70x is the distance PCB camera <--> nozzle tip

 The temperature reference value is the temperature during the last machine calibration.

SIPLACE X4I:

 Gantry 4 – position recognition with max. 3

fiducials

 Gantry 2 – position recognition with 2 fiducials

 Gantries 1 and 3 – dual position recognition

Legend

 1: Gantry 1

 2: Gantry 2

 3: Gantry 3

 4: Gantry 4

 T: Transport direction

C&P20A

Board Recognition - Centering the Board Fiducials Pickup and Placement Cycle for C&P20A

Student Guide (FSE) SIPLACE X Series and X4I

Edition 01/2009 EN C&P20A

263

7.4.4 Board Recognition - Centering the Board Fiducials

7-20: Board recognition run to target position of board

The fiducial is expected at this target position. The

PCB camera is moved from waiting position to this

fiducial position.

 Board position recognition is performed before

the first component is picked up.

 The gantry axes move the PCB camera to the

theoretical fiducial position. The camera takes

the picture of the first fiducial and the Vision

system calculates the center position.

7-21: Board recognition - centering the board fiducials

The centered fiducial now defines the actual

position of the board.

 The camera records an image of the 2nd

fiducial and the Vision system calculates the

center position of this image.

 The 2nd calculation is the deviation between

the target and the calculated fiducial position.

 All board fiducials are optically centered with

this procedure.

 This data is sent to the machine controller.

 Corrected values are now calculated for the

X,Y and angular position of the board.

 The gantry axes now move the placement

head to the first pickup position.

NOTE:

If synthetic fiducials are used, the procedure described above remains the same, although

inkspot recognition will now be performed after fiducial recognition.

C&P20A

Pickup and Placement Cycle for C&P20A Turning Nozzles 1 to 20 to the Pickup Angle (0° or 90°)

Student Guide (FSE) SIPLACE X Series and X4I

C&P20A Edition 01/2009 EN

264

7.4.5 Turning Nozzles 1 to 20 to the Pickup Angle (0° or 90°)

7.4.6 Checking the Nozzle Length for Component Recognition

7-22: Turning segments 1 to 20 to the pickup angle (0° or 90°)

 The segments in the C&P20A head are turned

in succession, from segment 1 to 20, to the

required pickup angle of 0° or 90°.

NOTE:

Each segment has its own DP drive

7-23: Checking the nozzle length ("component recognition by component

sensor before placement")

Component sensor measures at star pickup

position:

 Vacuum measurement: ’Segment open’ value

 The component sensor measures the length of

the nozzle. The measured length before

pickup is verified with the reference length.

 If a difference of -0.15 mm or +0.1 mm is

found, the gantry axes will move the

placement head into the service position for

replacement of the nozzle.

 Measurement is performed "on the fly" in the

star pickup/placement position.