Hi again Paul,
One last note.
In my wording notice that I used the word "non-conformance", not defect, reject, scrap, junk, etc....
The next step is MRB, where the real decisions/action get made in light of the facts, and in conjunction with customer involvement.
Gerry
> Date: Fri, 6 Dec 2013 08:32:37 -0500
> From: [log in to unmask]
> Subject: Re: [TN] Crazing
> To: [log in to unmask]
>
> Hi Gerry,
>
> Bill and I are doing well.
>
> I concur with your thoughts. If you find something using a method that
> is not required for the defect, it's still a defect.
>
> I am not happy with the idea that because I found the crazing during a
> microscopic examination it does not count.
>
>
> Sincerely,
>
>
>
> Paul Reid
>
> Program Coordinator
>
> PWB Interconnect Solutions Inc.
> 235 Stafford Rd., West, Unit 103
> Nepean, Ontario Canada, K2H 9C1
>
> 613 596 4244 ext. 229
>
> Skype paul_reid_pwb
> [log in to unmask]
>
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Gerry Gagnon
> Sent: December 6, 2013 8:21 AM
> To: [log in to unmask]
> Subject: Re: [TN] Crazing
>
> Hi Paul,
>
> Hope you and Bill B. are doing fine.
>
> I am assuming that you you were looking for something else and detected
> a "non-conforming" level of crazing.
>
> In my mind, this is an easy one because you found the non-conformance
> "along the way" while examining your microsection.
>
> Let me give you an easier analogy.
>
> While examining a region of an IST test coupon in transverse mount, I
> find a tiny piece of material bridging two conductors at high mag.
> Clearing away the conductor surfaces enough to measure if there is a
> resistance, I get a value in the MegOhm range.
>
> Is it a short?
>
> Unless things gave changed, Bare board continuity thresholds will not
> detect this phenomenon.
> Let's also say that innerlayer AOI (if performed) has a very high escape
> rate for this type of phenomenon or may not even detect it at all.
>
> Is the phenomonon a short per IPC A-610?
> My answer is yes, it is an unwanted connection, albeit a high resistance
> connection, and is difficult to detect.
>
> Does the fact that I found this short in a cross section under high
> magnification, while I was looking for something else, change anything?
>
> I don't think so, and I do not think IPC A-610 allows non-conformances
> that are found "along the way".
>
> Have a good one.
> Gerry
>
>
>
>
> > Date: Thu, 5 Dec 2013 16:05:41 -0500
> > From: [log in to unmask]
> > Subject: [TN] Crazing
> > To: [log in to unmask]
> >
> > I was just on a conference call where we found crazing (a separation
> > between glass fibers and the epoxy system), in a microsection. The
> > fabricator stated that this had to be evaluated looking at a board
> > macroscopically and could not be evaluated microscopically.
> >
> >
> >
> > Crazing is called out in IPC-A- 600 in section 2, paragraph 2.3.2 page
> > 18, which is "Externally Observable Characteristics". In A-600 there
> is
> > picture of a microsection showing the defect but it states that a
> > microsection is not required.
> >
> >
> >
> > In IPC 6012-2010 crazing is call out in 3.3.2.2, page 12, which states
> > (I am paraphrasing), "Crazing shall not violate greater than 50% of
> the
> > distance between adjacent conductors..." The document then refers to
> IPC
> > A 600.
> >
> >
> >
> > What is your take on their argument that crazing should not be
> evaluated
> > microscopically as per IPC?
> >
> >
> >
> > Sincerely,
> >
> >
> >
> > Paul Reid
> >
> > Program Coordinator
> >
> > PWB Interconnect Solutions Inc.
> > 235 Stafford Rd., West, Unit 103
> > Nepean, Ontario Canada, K2H 9C1
> >
> > 613 596 4244 ext. 229
> >
> > Skype paul_reid_pwb
> > [log in to unmask]
> >
> >
> >
> >
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