Electronics Forum | Thu Oct 19 13:14:34 EDT 2006 | lgroves
While I can only speak for Samsung equipment I believe that this would not be a problem for most modern machines as the local fid positions are usually programmable
Electronics Forum | Thu Oct 19 14:21:34 EDT 2006 | sliebl
Also, with our CS machines, I don't need to know the exact location of the fids, I just teach them to the machine. What the software does with the data is bisect the line the centerline between the fids to find the centerpoint of the part.
Electronics Forum | Thu Oct 19 14:32:53 EDT 2006 | curious
The fid is just a "known reference" location, the only advantage/difference is proximity to the part. It almost sounds like you are using the local fid as your part placement coordinates? So maybe the CS machine IS different but something doesn't sou
Electronics Forum | Thu Oct 19 14:37:30 EDT 2006 | curious
OOps, to quick on the draw. If you have the CAD data for you fids I'll bet if you input those numbers (not teach on the machine) they'll work. Do you teach your globals the same way?
Electronics Forum | Thu Oct 19 14:49:35 EDT 2006 | sliebl
We teach all of the fids. Globals and Locals. This is because we use a magnetic table, not a pass through conveyor. Without showing the machine the global fids, it has no idea where we've mounted the board.
Electronics Forum | Thu Oct 19 15:15:24 EDT 2006 | russ
to use local fids such as this you must use the cad data, when the machine knows where it is supposed to be and seeks there it reads where it (PCB) really is and then corrects the machine, it does not have to be symetrical at all. If you teach fids
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 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 | Fri Oct 20 05:33:24 EDT 2006 | Phil
The algorithm in our machines calculates the coordinate of the centre point between the local fiducials, compares it to the theoretical coodinate in the program data and applies any difference found as a "percentage" correction to all placement coodi
Electronics Forum | Fri Oct 20 07:03:46 EDT 2006 | sliebl
I really appreciate the input, guys. Having only had the opportunity to run the Contact machines, I was not aware that many of the other machines use coordinates for locals. Now about those damn, mid-chip solder balls.... oh, that's another topic.
