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MYData placement variations

Views: 2559

#42528

MYData placement variations | 30 June, 2006

Folks, who uses MYData's?.... In a previous life I was a fuji man and liked them I have to say, they were big n heavy and you could drop them from a plan and they would still work... well till they brought out the QP's but lets not go there. I did have a brief fling with a Universal GSM / GSM2 but it meant nothing and was short lived. Now I find myself working with MYData's and I have to say I find them fragile to say the least. The current issue is around placement of, well any device... the machine auto locates the fid's and starts to place, if you stop the machine to check its ok we see an offset of about 0.5mm. Now you would think it's a basic calibration issue, it's not... the machine passes all calibration tests well within the limits. It's not drifitng fiducails or bent nozzles or badly clamped boards or backlash on lead screws etc etc. MyData, who seem to be stumped told us to tighten the fiducial window (the opposite of what they recomended previously) and it has improved... but they can't fix it... anyone else get issues like this?

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#42532

MYData placement variations | 3 July, 2006

Hi,

I found accuracy issues with MYDATA's but your's seem a bit excessive, and might be something else. I often found when setting up a board that was panalised that if it was done wrong, you would get a slight error on one side of the panel because the setup was wrong, and it was doing a slight scale of the PCB in the panel.

Is one side of your panel better than the other? It could be this?

Also, is it just some components? If so, check the board supports. If the board is not supported right, the components will slide when placed. We had this issue with one QFP, until we found it was the board supports. Once that was sorted out, it was fine.

There are a few issues that I am having difficulty remembering that could cause a problem like that. So it should be easy to find, as .5 mm is a long way off.

Grant

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#42605

MYData placement variations | 7 July, 2006

I've seen the tool head move components if the component list isn't grouped according to size. If you group your taller components higher than the others then they will be placed later.

I used to see a lot of shifting with large keyhole vias used as fiducials, as they have a position tolerance seperate of the pad layout.

The only other thing I can think of at the moment is if your centering jaws are off or are warped/pitted. The fine tune Z unit should help you diagnose that if you haven't already.

Good luck, -OtherRuss

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Billy D

#42637

MYData placement variations | 10 July, 2006

Dude - check the centering jaws as well. If they're off a bit it'll do this as well. Is it just mechanically centered parts, or optically centered parts also?

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CL

#42705

MYData placement variations | 13 July, 2006

Is it possible that the PCB is moving? First try an autoscan of the fids and then immediately perform a manual trim which will bring the camera over to where it found the fid. If it is on, there is an offset drift in your axis or the PCB is able to move as the board is being placed. If it is not on, is the fid taught as a generic? If so, is it taught correctly? (go to the fiducial editor, select the fid and hit verify)

Good Luck

Chris

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#47851

MYData placement variations | 20 February, 2007

My machine TP9-2U have the same problem. I use the camera to walk through the program and it is off and not repeatable. I think the machine has backlash but I don't know how to tighten it up. Can you help??? Thanks, -Michael

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CL

#47858

MYData placement variations | 21 February, 2007

Good Morning,

We have 5 Mydata MY machines in separate lines. We are placing 0201's, uBGA's, CSP's, etc.... I cant say that we have never had accuracy problems but whatever caused the problems was identified and they are fairly accurate as far as I'm concerned. I agree with previous statements. 1) is it all parts or just mechanically or optical? 2)Is it just Hydra parts (assuming you're running Hydra) 3) If it is all parts and the offsett is in the same direction, autoscan fids, stop the build and immideately do a manual trim. Are the fid's propperly located? If so let the machine run 1/2 of the board and do the same. Are they still propperly located? If not it might be a position encoder causing drift. Note: depending on the direction of offsett will indicate the X or Y encoder.Are you having to reteach tool positions?

There are several possible causes for this to happen. Try to narrow down the symptoms and then look at possible causes for those exact symptoms. I know, easier said than done. Sorry for oversimplifying the situation. I know how frustrating it can be but so far, we have been able to identify the root cause for accuracy problems and keep them under control.

Best of luck

Chris

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#47871

MYData placement variations | 21 February, 2007

What type of Mydata is this ? TP or My series ?

Optical or Mechanical centering ?

How many hours are on the machine ?

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#48019

MYData placement variations | 27 February, 2007

This is the TP9-2U machine and have about 2000 hours on it. When I used the camera to walk through the program, it is not repeatable.

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#48030

MYData placement variations | 28 February, 2007

We recently scrapped our TP9-2U because of an issue similar to this.

The X-axis would overshoot the pick and place positions. This particular machine(2U)only has 1 X motor. The UFP's and the MY machines have a small fine positioning motor that is on the X-axis itself. The large X-motor on the back of the machine makes the fast coarse movements and the small x-motor on the x-wagon makes the fine movements.

Make sure that you don't have something simple going on like loose screws on the Y-wagon.

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#48121

MYData placement variations | 2 March, 2007

We have a TP9 and are having no problems placing 0402s or fine pitch QFPs. Try slowing down the accelerations on the X and Y axis. That increases the time it takes to place a part but I have found that it can help accuracy.

All the other posts have good info to check as well.

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