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Fiducial Mark coordinate error

已有 3766 次閱讀2012-11-19 16:00 |個人分類:PCB相關| fiducial, mark, coordinate

Let’s have a short view of our asmcor.txt which we need to create for our mfg file.

This *.txt file is use to do the SMT.

For example:

"",0,0,0,"DIM1",0

"",-14860,11160,0,"DIM2",0 (x:0,-14860;y:0,11160)

"",-19995,10971,0,"FID1",0

"",-23895,10971,0,"FID2",0

"",-16095,10971,0,"FID3",0

"",-12195,10971,0,"FID4",0

"",-12100,708,0,"FID5",0

"",-19900,708,0,"FID6",0

"",-23800,708,0,"FID7",0

"",-16000,708,0,"FID8",0

The green number is the range of the coordinate of our panel, but the red number is bigger than the green number.

The error is the “x” coordinates of fiducial mark out of the range of DIM.

For the DIM points make the range of coordinate of the panel like this:

The coordinate of all the components are must in this range.

Why dose the error occur?

At this project, we use an old panel date to create a new panel for our own PWB. The fiducial marks are existent on the panel. And we use the old fiducial marks curtly, and then the error occurs! The figure of the fiducial mark is at the location where we put it, but the property of the figure is another coordinate. This is a bad thing. This makes the error which is mentioned at the front of this document.

This error can make the wrong operation when we do the SMT. So we need to check the coordinate of the fiducial mark when we design the panel.