Jim
Editorial: You should always track (record and report) rework  Obviously
the detail required (eg. bridge on U16 pins 2,3) depends on your
customer requirements, class 1 doesn't require that much detail whereas
for high reliability I believe it is essential.  But you have to have
it.  I have used defect records for:
 - root cause tracking for field fails (this solder joint failed - has
it been reworked already or was it made like this???)
 - tracking the quality level of a process, quantifying improvements,
identification of the need for improvements
 - measuring shift to shift (1st Vs 2nd Vs 3rd) variation on the same
process
As they say, if you don't know where you are you have a hard time
getting where you need to be...

Assuming class 3 (my experience), all defects should be tracked in a
database that you can query, with sufficient detail that you can
identify common factors and the defect level.  I've seen it done as
percentage yields, ppm/ofe, %/ofe...  Personally I prefer to measure
defect rates in parts per million defective / opportunities for error.
The key is to have a clear definition of what the number means and how
you are going to measure it, and stick to the definition

regards,

Graham Collins
Process Engineer
Litton Systems Canada
(902) 873-2000 extension 215
.

> -----Original Message-----
> From: RSIMathis [SMTP:[log in to unmask]]
> Sent: Thursday, March 19, 1998 2:09 PM
> To:   [log in to unmask]
> Subject:      [TN] PCB assy defect reporting criteria
>
> My company is unclear as to how we should be recording and reporting
> defects
> with our PCB assemblies.  Some think that all shorts and opens prior
> to touch-
> up should be reported as defects, others believe we should report only
> defects
> found after touch-up.
>
> Questions:
> 1.)  How do other companies do this?
> 2.)  Is there an industry standard method for reporting defects?
> 3.)  Is there an IPC (or other organization's) standard or manual for
> reporting procedures?
>
> Thanks to all,  Jim Mathis
>
> ################################################################
> TechNet E-Mail Forum provided as a free service by IPC using LISTSERV
> 1.8c
> ################################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
> following text in the body:
> To subscribe:   SUBSCRIBE TechNet <your full name>
> To unsubscribe:   SIGNOFF TechNet
> ################################################################
> Please visit IPC web site (http://jefry.ipc.org/forum.htm) for
> additional information.
> For the technical support contact Dmitriy Sklyar at [log in to unmask] or
> 847-509-9700 ext.311
> ################################################################

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################