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Fiducial replacements?

Views: 9721

Fiducial replacements? - Nov 30, 2007 by Paul M.  

Fiducial replacements? - Nov 30, 2007 by PR  

Fiducial replacements? - Nov 30, 2007 by Mika  

Fiducial replacements? - Nov 30, 2007 by Bert  

Fiducial replacements? - Nov 30, 2007 by Mika  

Fiducial replacements? - Nov 30, 2007 by Mika  

Fiducial replacements? - Dec 03, 2007 by Paul M.  

Fiducial replacements? - Dec 03, 2007 by Stephen  

Fiducial replacements? - Dec 03, 2007 by davef  

Fiducial replacements? - Dec 03, 2007 by gregp  

Fiducial replacements? - Dec 03, 2007 by Real Chunks  

Fiducial replacements? - Dec 03, 2007 by Real Chunks  

Fiducial replacements? - Dec 03, 2007 by aj  

Fiducial replacements? - Dec 03, 2007 by Pitbull  

Fiducial replacements? - Dec 03, 2007 by SteveK  

Fiducial replacements? - Dec 04, 2007 by Paul M.  

... - Dec 07, 2007 by Mika  

Fiducial replacements? - Dec 07, 2007 by ito  

Fiducial replacements? - Dec 10, 2007 by davef  

Fiducial replacements? - Dec 17, 2007 by Kelcatzeye  

Fiducial replacements? - Dec 18, 2007 by Paul M.  

Fiducial replacements? - Dec 18, 2007 by Darby  

Fiducial replacements? - Dec 19, 2007 by Kelcatzeye  

Fiducial replacements? - Dec 19, 2007 by Paul M.  

Fiducial replacements? - Dec 19, 2007 by Darby  

Fiducial replacements? - Dec 20, 2007 by Kelcatzeye  

Fiducial replacements? - Dec 20, 2007 by Paul M.  

Fiducial replacements? - Dec 28, 2007 by Real Chunks  

Fiducial replacements? - Jan 02, 2008 by Paul M.  

Fiducial replacements? - Jan 02, 2008 by Real Chunks  

Fiducial replacements? - Jan 06, 2008 by mac88  

Fiducial replacements? - Jan 10, 2008 by Chris1963  

#52717

Fiducial replacements? | 30 November, 2007

Maybe a silly question, but...........

Sometimes we get PCB's in with defective(distorted) fiducials that the production equipment(printer, PnP, etc) does not recognize.

It would be great if there was a product out there to replace the defective fiducial.

I'm talking about an adhesive shiny/metal dot(.035, .050, or whatever size shape one needs) to substitute for the original fiducial. Just stick it on the PCB and go. I know it would be hard to place it exactly where the original fiducial was, but I imagine one could be placed close enough.


Anyone out there ever heard of this?

Is there a place one could purchase these "replacement" fiducials?

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PR

#52720

Fiducial replacements? | 30 November, 2007

I hope you are not building for the aviation industry.

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#52724

Fiducial replacements? | 30 November, 2007

One of our former SMT Technicians used a component we pick and place for this purpose.

The component is a bond pad that is soldered to a ceramic PCB during SMT assembly. The assembly is now obsolete. I tried looking up the manufacturer's part number in our system for you but it's no longer listed there.

I encourage the SMT Techs and operators to reject boards with bad fids as nonconforming materials.

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#52728

Fiducial replacements? | 30 November, 2007

Hi Paul M,
There are no silly questions but silly answers.. and here is maybe a few if I understand you correctly: If you consider place anything less than a 1.27mm (50mil) pitch component down or a chip less than a 1210, hey it maybe don't even work if we are talking about a 2.54mm (100mil)pitch component package and you still need to fulfill the IPC rules and get a good solder paste print and component placement & soldering.
Don't even consider this "replacement fiducial" as an option!

As I see it (based on the limitation of detailed info you gave us) you have 4 options:
1. Try to tweak the fiducial camera settings in the program/machine: lighting, threshold, surrounding pattern, search area, inner/outer lighting (depending on what vision system you are using) and make sure that there are no similar surrounding patterns such like a test point that has the very same diameter as the fiducial nearby.

2. If it is HASL surface finish on the board (If Not skip to No.3 below), then an uneven surface will be at the fid's and pads. This will cause the light to reflect a strange pattern back to the fiducial camera and it will see dark spots in the fiducial area. If No.1 above didn't work and if it is only a few board's to be produced, concider rubb the existing HASL (thinned) fid marks with a simple eraser (back end of a pencil or eq.). This will in such case make the surface matt/dull and therefore the image to be even and bright, for the fiducial camera & recognition vision system.

3. If You have tried No. 1 & 2 above, consider contact your pcb manufacturer and tell them that you are Not going to accept this low quality, please make new ones. This only works if you can actually pinpoint that they have made a poor fabrication of your pcb:s.

4. Out of business. Unless...

I think you can make an easy calculation of the time consuming and the costs...

BTW. it could be interesting to hear what type of boards regarding surface finish, typical component packages on it and which type of SMT-equipment you have.
And... you have not described exactly (in detail) the actual fiducial problem for us...

If You have any questions, please don't hesitate.
Best Regards
Ps. Sorry for my poor english and grammar. Ds.

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#52731

Fiducial replacements? | 30 November, 2007

Hi Paul,

It may not be the perfect replacement for a proper fiducial but I have had some success using thru-holes for fiducials. The tightest pitch part we place is 0.8mm however 0.032").

If the thru-holes are drilled accurately and you are able to use "negative" fiducials (black on white) this may work for you.

Regards,

Bert

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#52732

Fiducial replacements? | 30 November, 2007

Option 5.
If you have thru-holes as Bert mentioned, and if it is plated even better, you still have a fairly good chance to proceed.
As long as you know the exact coordinates.
But this can be tweaked afterwords, the important thing is that you got the repeatable in placement.
/Best Regards

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#52733

Fiducial replacements? | 30 November, 2007

BTW, Option 6.
Bear in mind though, In the stencil printer if you run into a problem like this, it will not work with the holes...Only what's in the stencil...
We have under some rare circumstances used 1-2 pad's on opposite corners and on very large component pads/apertures for this to work for recognition. Otherwise the search area could/will take the next wrong pad/aperture...
Then the result will be a misalignment of paste to pad.
/Best Regards

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#52751

Fiducial replacements? | 3 December, 2007

The PCB's are supplied by the customer. No options. The BOSS say's get it done, make it work, I don't want to hear it. My BOSS is a psychotic idiot.

The printer is a DEK with no options for manual fiducial over-ride. I think my idiot BOSS wrote the software for this machine. Friggin idiot.

Yea, I can reprogram the DEK and use pads/apertures for FIDS, but it's a pain in the ass for ONE or TWO PCB's, then I have to re-program it back for the good PCB's.... it's a pain in the ass, I got better things to do with my time.

The PNP has manual fid over-ride, so that's not a problem for 1 or 2 PCB's.

And yes, I've used the "pencil eraser" to clean up fid's.

Aviation? Who gives a sh*t where the product is used. Sheeeesh..........

No one ever seen/used sticky replacement fids?

hmmmmm.......... maybe a new business venture?

Did I mention that my BOSS is a idiot?


I need a drink........

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#52755

Fiducial replacements? | 3 December, 2007

I got nothin', other than that was a pretty fine Monday morning rant. ;)

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#52756

Fiducial replacements? | 3 December, 2007

I've done a couple fiducial transplants from populated boards to non-populated boards in the past.
I've also used a soldering iron on irregular shaped HASL fids to round them out.

And that is a vintage rant.

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#52757

Fiducial replacements? | 3 December, 2007

Paul: We all live in Dilbert-world. Some people think Scott Adams is kidding, but we know he's not.

Give yourself a break and just use replacement pads used in repairing damaged BGA circuitry. For instance: http://www.circuitmedic.com/products/CS015020AS.shtml

We have no relationship, nor receive benefit from the company referenced above.

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#52760

Fiducial replacements? | 3 December, 2007

I hope this isn't a silly question but...
isn't there a way to manually override when a fiducial fails vision? I can't imagine a machine that would be available without this basic feature.

Greg

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#52763

Fiducial replacements? | 3 December, 2007

Peelable solder mask works well. Hand dispense and peel off after. Paint sticks work OK, but it depends on the mfger of the paint stick. In both methods you hand apply after screen print. Your Dek can be taught pads to get by. You may have to teach board by board depending on how steady a dot you can dispense.

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#52764

Fiducial replacements? | 3 December, 2007

I think I'm in love!

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#52767

Fiducial replacements? | 3 December, 2007

Hey gregp,

I am not aware of any way to manually override a bad fiducial on a Panasonic MV2VB or MV2C.

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aj

#52768

Fiducial replacements? | 3 December, 2007

Hi,

I have often used Plated drill holes for reference with good success.

You should advise your customer to put 4 fiducials on the board which covers both diagonals this way you have the option to change fids ( or even get them to put extra fids anywhere on the board)

aj...

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#52769

Fiducial replacements? | 3 December, 2007

Why don't you create a seperate program using pads as fids. Then, the operators can load this program at the end of the run and print the boards with the bad fiducials. You don't have to keep altering the program, your boss can can go about his day being an idiot and everybody wins.

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#52773

Fiducial replacements? | 3 December, 2007

I don't know how accurately you're going to be able to put a replacement down. You could use BGA replacement pads, but that is a lot of time and the results will be shakey.

On the DEK, make a copy of your program and teach some pads or through holes as fids. For a given lot, the drill offset is often pretty close, so you print a couple, figure out the offset you need for the machine and you ought to be able to get those last 25 or so without too much greif.

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#52782

Fiducial replacements? | 4 December, 2007

Thanks for all your suggestions.

I like the BGA replacement pad option the best. Reprogramming/programing? Forget it. That's what I'm trying to avoid. I'd be there all friggin day long, with all the loser "Labor Only" accounts we have. And oh, the paper work/floor documentation involved with multible programs? Oh the humanity. Makes my ulcer bleed just thinking about it.

But.....

I think this will be a non-issue for me in the near future.

Cause.....

You see, come New Years, I think I'm gonna tell my idiot BOSS to stick it, you know, where the sun don't shine?

That's gonna be my New Years resolution, to rid myself of higher up idiots. I deplore higher up idiots.....

Happy New Years !!!

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#52836

| 7 December, 2007


ito

#52837

Fiducial replacements? | 7 December, 2007

You need fiducial not only in printer, so i recomend to use a bga kit and rework station, in the rework station you can easylly place very acuratly the new fiducial. use some glue to keep in place

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#52851

Fiducial replacements? | 10 December, 2007

why need too fiduchals?

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#52854

Fiducial replacements? | 10 December, 2007

#52919

Fiducial replacements? | 17 December, 2007

I would refuse to use the PCB's if they are not usable as specified. The fiducials line everything up with the artwork...how can this accurately be done in a manual way?

Is the risk of reworking fiducials worth the cost of the potential financial impact of bad parts, or your company's reputation? I would look at the overall risk and (with financial impact) and use that to make your case to NOT use defective PCB's.

Good Luck! :)

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#52939

Fiducial replacements? | 17 December, 2007

Paul M...sounds like you work for a guy I used to work for Paul L...WHEN you leave, keep in mind the bigger idiot you are, the higher they promote you!!

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#52949

Fiducial replacements? | 18 December, 2007


Can't beat em, join em?


hmmmmmmmmmm.......interesting.

I'll cognitate on that.

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#52951

Fiducial replacements? | 18 December, 2007

Aviation.Ha-HA-HA-HA. yes indeed who cares?! i got a bit of a belly ache now from laughing at the Fat Bastard's posting on aviation. a subject totally and utterly unrelated to the subject at hand.

I agree wholeheartedly with ya, Paul M. me chap. we're all pretty frustrated in this industry. Those of us ogres with enough insanity to do this type of work still and to top it off report to a psycho of a boss

I must say i do speculate if there is a Fiducial Repair kit anywere's, example, BEST electronics or some other outfit that sells PCB repair.

Dave F or any other laddies out there,you chaps know if this exists??

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#52965

Fiducial replacements? | 18 December, 2007

Paul,
For the Dek and following equipment - seperate all the "bad fid" pcbs and process them seperately.
Drill a hole as accurately as you can through the bad fids making sure you leave some white area around them.
Set up and run a seperate program using black fids.
I do it all the time.

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#52968

Fiducial replacements? | 19 December, 2007


This doesn't sound like standard processing to me...
having to set up a separate program, drill holes, etc...
to use bad boards from a supplier.
If the supplier was a truly good supplier, they would send replacements ASAP and fix the issue.

Again, good luck!

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#52973

Fiducial replacements? | 19 December, 2007

Kelca.....

I don't think yer getting the picture here. These boards are supplied by the customer. They are "Labor Only" accounts. We have NO control of the PCB's or any of the parts for that matter. These Labor Only customers show up at the back door and drop off a dumpster full of shit and asked the IDIOT boss if we will build it, you now, turn our dumpster full of shit into a gold brick? The IDIOT boss (in which, by the way, is the owner of this pop stand) say's yes because of dollar signs in his eyes (he has no clue on WHAT we even do here, let alone HOW it's done). The BOSS orders the LOWERDOWN folk to build it, under budget, whatever it takes, don't complain and JUST GET IT DONE.

We do not have an option to reject these PCB's. It's not a matter of shit-canning the crappy board supplier and getting a better one.

Is this clear? Do you understand now?

And oh...... I did get your PM's, I am NOT looking for a better board supply house. Just trying to get a bandaid on this gaping wound called "Fiducial-Replacements".

Thanks anyways.

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#52981

Fiducial replacements? | 19 December, 2007

The other thing you could do is fit the cameras with a catseye lens.
With my way all the data says the same apart from the fid diameter/shape and logic off/on.
Just as accurate as any other method,
a lot cheaper - cost = 1 drill,
less nerve racking and
much, much quicker.

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#52988

Fiducial replacements? | 20 December, 2007


Paul,
My sincere apologies for striking a nerve - that was not my intent. I do not work for a board house, nor am I pushing anything on you. My comments only come from my history of having to use parts that made manufacturing a nightmare. I do understand what you mean about a customer that dumps all the parts on you and says build it - its frustrating as hell when your company accepts jobs with only dollar signs in their eyes and expects miracles.
Again, my apologies. I wish you the best of luck.

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#52992

Fiducial replacements? | 20 December, 2007


No worries Kel !!!

Thanks for yours and everyones input on this subject.

Merry Christmas !!

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#53045

Fiducial replacements? | 28 December, 2007

Paul,

Did you tell your boss to "stick it" yet?

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#53053

Fiducial replacements? | 2 January, 2008

No Chunks, I did not tell him to "stick it", yet.


I've decided on a new way of handling this IDIOT.


I'm gonna try some passive-aggressive techniques.

You know. Sarcasm and manipulation?

Will see how that works.

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#53054

Fiducial replacements? | 2 January, 2008

Good for you. We all have to play the game in one fasion or another. It goes with the paycheck.

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#53084

Fiducial replacements? | 6 January, 2008

If the machine or machines couldn't recognize the fiducials, you can grind it with a fiberglass eraser. If the fiducial are missing you can use tooling holes, and/or via holes. You can verify the hole size and tolerance on the PCB assembly drawing. Also, this drawings provide the coordinates with respect of the absolute PCB zero.

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#53126

Fiducial replacements? | 10 January, 2008

I have read all the replies here and have yet to see this one which I know works when our fids are HASL and distorted, thus unable to seem uniform enough for the vision systems on our MPM's or MyDatas to see them clearly.

Using a stainless steel needle pick, scratch the entire surface of the fids which then reflect light more evenly making the dark areas appear brighter.

It really does work....give it a shot.....cheap and easy and no re-programming for you!

Good luck!

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