Bob,

For class 3 boards of that complexity you cannot rely on visual inspection to weed out 100% of the quality problems! What you want is visual + AOI + X-Ray and also functional test. No functional test, no certainty that you've caught everything. On top of it, testing has to have a proper coverage.
Then, you'll need some screening, like thermal shock or burn-in, in order to catch infant mortality issues that get away even after having done all the above.

And this will, eventually, ensure good quality, which means good workmanship. But things don't have to stop here either, as you have no idea about the long term reliability of the product, which is intimately related to design (Werner would have had many things to say here).
So you'll need to wrap it up with proper ESS screening.

But now that I'm done ranting, I see your mandate is to perform inspection only. Maybe you could get away with the reliability part, but I don't believe you can commit to properly fulfilling your mandate without functional test and infant mortality screening. Believe me, I've been down that path. 4000 parts and this complexity means that, if you judge based on DPMO, there is at least one defect on each board. Try and find it!

To end on a sweeter note, of course you could commit to the task, if not you, somebody else will, but make sure the contract has provisions that will allow your company to fight the endless spiral of customer returns.

Regards,

Ioan Tempea

This e-mail, and any attachments, are intended solely for the use of the intended recipient(s) and may contain legally privileged, proprietary and/or confidential information. Any use, disclosure, dissemination, distribution or copying of this e-mail and any attachments for any purposes that have not been specifically authorized by the sender is strictly prohibited. If you are not the intended recipient, please immediately notify the sender by reply e-mail and permanently delete all copies and attachments.

-----Message d'origine-----
De : TechNet [mailto:[log in to unmask]] De la part de Bob Wettermann
Envoyé : Tuesday, October 22, 2013 4:16 PM
À : [log in to unmask]
Objet : [TN] Inspecting Class 3 Assemblies

Dear Technetters:

I think these things come in bunches.

We are being asked to perform contract inspection of Class 3 medical PCBs.
I would categorize this board as "high complexity" with BGAs, UHDI connectors, 0201s and about 4,000 parts. There are 100+ boards.

Obviously performing this manually will would take many hours and based on previous experience, be only 80% effective using a single set of eyes.

So my question for those of you building IPC-A-610 Class 3 product for mil, aerospace or medical is how do you insure that class 3 solder joint and other inspection criteria are met? The AOI we have will not do the trick!
The leadless devices and BGAs we will inspect via XRAY. Other ideas for doing this "offline"?

Bob W/BEST


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________