Just a few words on terminology.
The term "nonconforming" is used in several IPC published documents and unfortunately don't always have the same intent. Some docs (particularly those dealing with boards) only identify two conditions - acceptable and nonconforming. In that case, nonconforming means defect and requires dispostion. IPC-A-610B added "nonconforming" with every occurrence of either the Process Indicator or Defect conditions. In 610B then, the official interpretation nonconforming
Except for some explanatory words up front, the C revision to 610 will not use the word "nonconforming". In the case of 610B, I would encourage you to put a filter on the word and ignore it.
Because 610B is still the most current published assembly acceptance document, you are stuck with that word all the way through, and your request for clarification is not the first one we've received.
Now to the main part of your question. Of course, you are aiming towards the Target condition of everything you build, and you're comfortable with Acceptable. Defect is understood--it requires disposition to determine what to do with the "bad hardware". But what about the hardware that doesn't meet Acceptable, but isn't so bad as to be a defect, or that a rework operation is likely to generate more failure mechanisms than are corrected? The most common option is to identify them a name that reflects the process may be slipping--a process indicator.
Of course, identification of an indicator suggests you would do something with the knowledge that the process is potentially going out of control. If you have a functioning process control program, you would track those process indicators and the process engineers would use them to tweak as necessary. Ideally, if the program is working, process indicator counts slowly increase until a threshold is reached, corrective action is taken, and process indicator counts reduce substantially. Continuous process improvement comes to mind.
So now we watch the TechNet responses and see if anyone is willing to state they actually track and use process indicators like J-STD-001 says you should.
Jack
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Jack Crawford, IPC Director of Assembly Standards and Technology
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>>> Tim Devaul <[log in to unmask]> 11/10/99 12:08PM >>>
I am in the process of switching from my company's internally developed standards to IPC, the only outlying issue is how we are going to handle nonconforming process indicators as they arise. Could I get some feedback as to how your companies handle
them?
Thanks, Tim
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