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Best/Common Practice in Blank PCB QC

#23457

Best/Common Practice in Blank PCB QC | 21 February, 2003

I would appreciate any feedback that can be provided regarding best practices and common practices for control of incoming PCB blank quality. How common is sectioning and other sorts of analysis? Do these efforts result in real improvements in vendor quality? Any recommendations as to useful reading in this area would be helpful. Thanks in advance.

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MA/NY DDave

#23460

Best/Common Practice in Blank PCB QC | 21 February, 2003

Hi

"PCB blank quality. "

I am not sure what the word blank means. -------------

I can think of piles of places for you to start study. First digest some of the IPC stuff. They have some good pictures.

I would also start collecting defects that are attributed to PCB defects. There are many, and growing.

As a QE/QC Cross Sectioning should normally be performed at the PCB shop and then supplied to you.

YiEng MA/NY DDave

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MA/NY DDave

#23461

Best/Common Practice in Blank PCB QC | 21 February, 2003

Hi

"PCB blank quality. "

I am not sure what the word blank means. -------------

I can think of piles of places for you to start study. First digest some of the IPC stuff. They have some good pictures.

I would also start collecting defects that are attributed to PCB defects. There are many, and growing.

As a QE/QC Cross Sectioning should normally be performed at the PCB shop and then supplied to you.

YiEng MA/NY DDave

This message was posted via the Electronics Forum @

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#23486

Best/Common Practice in Blank PCB QC | 23 February, 2003

We section no bare boards at incoming. If we have a problem that needs investigation, our suppliers do the sectioning for us. If we didn't trust their analysis, we'd: * Get a new supplier. [There is tons of capacity in this industry.] * Use an independant lab.

Our suppliers routinely section coupons on fabricated panels and run SPC charts on the plating thickness in monitoring tank life. Our QA-types poke around this stuff in their never ending effort to wrangle free lunches out of suppliers.

We visually inspect and check solderability at incoming.

Questions are: * Would a c of c accomplish the same things as you're trying to accomplish with sectioning? * What is your goal in performing this analysis?

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#23487

Best/Common Practice in Blank PCB QC | 23 February, 2003

"Blank" means "bare board". Gray beards used this expression a lot. It has stuck in many companies, even after the old timers went to work on the BIG wave solder machine in the sky.

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MA/NY DDave

#23488

Best/Common Practice in Blank PCB QC | 23 February, 2003

Hey

No fair Davey F, I got a grey beard and I don't use or know this "Blank PCB" term. I shave so they think I am younger and let it show otherwise for the girls.

YiEng, MA/NY DDave

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#23490

Best/Common Practice in Blank PCB QC | 24 February, 2003

YiEng, MA/NY DDave,

Look at: * Description on first item on this list: http://laser.jlab.org/bairweb/hardware/vme/vme_spares.asp

* Description of first item on each list: http://www.audiocircuit.com/9120-valveamplifier-circuit/Diy/Diypackages/CurcioAudio-CUR/9120DDCUR.htm

* Text under "cart" for the first item: http://www.soldertime.com/cart/Emulators.htm

Say "uncle" ;P

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Dreamsniper

#23507

Best/Common Practice in Blank PCB QC | 25 February, 2003

"We visually inspect and check solderability at incoming."

Would you mind sharing how you are doing them? Is it really necessary to inspect visually using a microscope all or every PCB's delivered by the supplier? If not how will we check the quality...by batch?

Thanks,

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#23508

Best/Common Practice in Blank PCB QC | 25 February, 2003

I don't know the precise scheme, but it goes something like this ...

WHAT TO DO * Use the general work instruction that applies to all boards. It goes into dimension and hole checking processes. It talks to visual instection of solder mask, solderability protection, hole plating, legend ink on pads, warp/bow/twist, and all that. It gives a solder float procedure. It repeats the J-STD-001 inspection tools. * Use a specific work instruction, if one is required for that board, that applies to the board being received.

HOW OFTEN TO DO IT * It depends on history. * If a supplier delivers five more lots without complaint, we don't inspect. We just verify that we got what we asked for. Regardless, we do a solder float on all board lots. * If the supplier or the part is new, we check everything, down to ear wax. * After we feel moderately confortable, we sample, probably c=0

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#23509

Best/Common Practice in Blank PCB QC | 25 February, 2003

OK. Let's turn this up a notch.

How do you qualify [certify] your inspectors?

How does this qualification [certification] include testing for vision and color differentiation?

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MA/NY DDave

#23513

Best/Common Practice in Blank PCB QC | 25 February, 2003

Hi

UNCLE!!! UNCLE!!!

You know maybe I do remember this term, yet it is so long ago it doesn't ring a clear bell. From the stuff you passed over it had to come from the electrical technicians and engineers. Bare Boards was a more common term in my woods.

A Populated Board of course is with components So a Blank or Bare Board must be without.

YiEng MA/NY DDave

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Kevin Facinelli

#23570

Best/Common Practice in Blank PCB QC | 28 February, 2003

One easy and often over looked step is to call out IPC-6012A compliance on the PO. You will also need to call out the class status. If you get in an issue regarding quality you will have a resource to fall back on. Sounds simple but ask your buyers if it is on the PO....I bet in a lot of cases this simple step is forgotten.

Kevin

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MA/NY DDave

#23577

Best/Common Practice in Blank PCB QC | 28 February, 2003

Hi

You are right. I guess some of us missed this point in the way this on line dialog works.

I like to put the specification that the PCB supplier must adhere to, on the Physical Print. The Physical print is often used by outgoing and incoming inspection groups. For some suppliers they have to make up their own work folders due to limited customer documentation. Now the PO is OK and good as a back up or as part of the start up phase yet the Physical Print, and less so the Final Inspection Instructions, is by far the best place from the customer's side that I have seen to list Specification/Inspection Criteria. Yes the customer side of Inspection can also be used yet the customer should push-down so that Outcoming Inspection/Verification does most of the work.

This from what I have read continues to answer the question posed by our topic launcher.

Great I always love a new overlooked twist.

YiEng MA/NY DDave (CompuFlex

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#23767

Best/Common Practice in Blank PCB QC | 11 March, 2003

Hi All, Thanks for the helpful discussions on this. We're working at digesting the IPC-6010 series now. G. P.S. Salt and Pepper beards use "blank" too.

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MA/NY DDave

#23768

Best/Common Practice in Blank PCB QC | 11 March, 2003

Hi

You are a young guy yet, I bet!

No fair with that taste of that old black or dark beard effect. It was great while it lasted, yet I like this new grey stuff. Too bad in the USA it is seen as a Done-With it affect.

Shave the face and almost no one knows if you stay fit.

I have some old buddies and former big whig managers that are on National things and no one can guess their age due to this shaving thing.

YiEng, MA/NY MrDave

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