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BGA-3500 Series Manual 5/01
10. Remove the V Block and replace it with the height reference block so that the block sits on the bare
component slide. With the Z-Axis knob rotated fully clockwise and the component lifted to it’s top posi-
tion, rotate the component height adjustment knob (Fine Z-Axis knob located on top of the vacuum
head assembly) so that the component’s legs or balls are barely in contact with the height adjustment
block. This step brings the component into focus. Every component varies in thickness and this differ-
ence must be compensated for. Since component thickness and ball or lead height varies with different
components, this step is required when changing between component types. Please note: This step is
not required every time a component is being placed, but only when changing to a different type or
height component.
11. Pull out the prism by sliding the silver bar on the right of the placement arm back towards you. After
completing this step, you will notice an image of the pad pattern on the PCB and the component balls
or leads appear simultaneously on the monitor.
Please note: With the prism retracted you will see an image on the monitor, it is an internal part of the
machine from the component’s path.
12. The next step is to view a dual image of the pads on the board and the balls or leads of the component
simultaneously. This is accomplished by the following procedure:
a) Adjust the zoom, focus, and lighting so that the pads on the board and the component’s balls are in
focus, can be viewed clearly, and that the lighting is adjusted so the two images can be easily
segregated.
b) Unlock the X and Y-axis by moving the X and Y locking bars on the board holder from the vertical to the
horizontal position. Make coarse adjustments at this point by sliding the board holder to allow the com-
ponent legs or balls, and the corresponding land pattern to be roughly overlaid. After this image is
obtained, lock the X and Y–axis by switching the locking bars from the horizontal to the vertical posi-
tion. After both the X and Y-axis are locked, fine adjustments can now be made by rotating the X and Y-
axis micrometers until the two images are precisely overlaid. At this point, you can also make adjust-
ments to the angle at which the component is viewed (in reference to the land pattern) by rotating the
theta control knob (located on the right of the vacuum head assembly).
c) Center the total image, in reference to the monitor, by adjusting the two centering screws (located above
the vision splitter knob).
d) Adjust the lighting of the component and the printed circuit board so that they are equally visible and
of equal illumination.
Note: Step “e” is necessary for placing QFP and large BGA components. This operation is not possible on
the CSP-3500 Series Systems.
e) Rotate the vision splitter knob so that only the corners of the component can be viewed. Increase the
zoom and adjust the focus to obtain a clear image of only the corners of the component. Inspect the
alignment of the component corners under high magnification and make any fine adjustments. This step
is recommended because once the corners of the QFP or large BGA are aligned, the center legs or balls
of the lead array are aligned automatically. If the image obtained is not a “true” split, and the symmetry
appears to be imperfect, the image is not centered. Center the image by adjusting the two knobs locat-
ed above the vision splitter.
After you have inspected the alignment of the component with the pads of the PCB and no final adjust-
ments are required, retract the prism by pushing the prism slide bar horizontally away from you. Lower the
component into place by rotating the Z-Axis knob counterclockwise.
