Electronics Forum | Wed Feb 08 11:51:13 EST 2012 | partsalesnti
Does anybody still use local fiducials for fine pitch parts in board design?
Electronics Forum | Tue Jun 14 11:02:53 EDT 2005 | Stefan
I would rather take Bobpan's advise. If the placement is calculated from the center of two fiducials, than the placement should be off by 1/2 of the distance of the two fiducials, but not by the offset of that one fiducial. However, your approach in
Electronics Forum | Fri Oct 20 04:10:31 EDT 2006 | Base
By the way: I've also used the corner pads as if they were locals. You can take a bitmap-picture of the pattern, store it and refer to it as a fiducial. Works great and you're sure they don't wander all over the place w.r.t. to the component's XY.
Electronics Forum | Tue Feb 20 14:39:59 EST 2018 | harlymh
Is it good practice to use a PCB mechanical drill hole as local fiducial? Would it increase my placement accuracy? Or should I stick to my panel fiducials? We're using a panel with 4 boards and we're trying to reach a 50 microns accuracy.
Electronics Forum | Fri Jun 10 21:22:36 EDT 2005 | KEN
JD, fiducials are merely land marks. The vision processor will measure the actual location and compare it to the CAD location. It does not care if the design is symetrical, asymetrical or what. In the case of a single center design fiducial (which
Electronics Forum | Thu Oct 19 16:35:22 EDT 2006 | jdengler
Steve, I believe Contact Systems is the only company that uses local fids in this way. All othe machine have coordinates for the local fids. When measuring the fids it applies any error from the fid measurement to the 1 component it's linked to.
Electronics Forum | Fri Sep 27 10:54:55 EDT 2002 | yngwie
Thank you pr. It was much appreciated. Is this mark normally act like a global fiducial/local fiducial for mBGA ? Is this a standard mark that can be read by the placement machine? what is the typical size of this mark ? are they masked ? thank y
Electronics Forum | Mon Mar 01 16:26:38 EST 2004 | rhdez
Is this problem with local fiducials or global? Is the problem on the same equipment? Is this a cad file o centroid? How are you measure the coordinates?
Electronics Forum | Tue Jun 14 07:29:12 EDT 2005 | jdumont
So I set up a board yesterday and did a test run. It appears that the spacing does matter on my machine. It placed the part off-center the same amount as one of the fiducials. Im going to look more into fixturing and placement pressure adjustments I
Electronics Forum | Thu Feb 16 02:50:24 EST 2012 | fadzril
In current conditions with new high tech machines, the requirement for having local fiducial marks can be dropped. Plus, using the fiducial marks of course will improve the mount accuracy, but will increase the cycle time. Compare both conditions & s
