Richard,
Yes it is so and I´m aware of that. I was a bit confusing from a
missunderstunding the english text on: "Defect Condition:..."
from your e-mail.
It left clear, no reliability issue from this minimum sideway round
terminal bent not affecting seal etc, etc....
Thank Gregory for your coop. on pictures.
best regards, gratefully, Ricardo M.
>>> "Stadem, Richard D." <[log in to unmask]> 21/01/2016 18:22
>>>
If the design violates the standards as written, then it is up to the
design house to take responsibility if their documentation directs you
to do so.
Situations like this, if they do in fact violate the standards, should
simply be dispositioned and approved by the MRB team, which means the
customer buys into the No Defect or Use As Is decision and signs off on
it as well. It is then AABUS (As Agreed Between User and Supplier).
From: Ricardo Moncaglieri [mailto:[log in to unmask]]
Sent: Thursday, January 21, 2016 12:34 PM
To: Stadem, Richard D.; TechNet E-Mail Forum
Subject: Re: [TN] Terminal Bent More than 10% Diameter
Richard,
Thank you very much.
Just want to clarify my understanding.
Do you define as Defect Condition a minor bend which meets design
requirement? (It wouldnt be a Defect)
A minor bend which avoid to meet design requirement, this condition do
confirm a Defect, upper condition of course not.
Resuming: our case is not a Defect and will not affect performance
reliability.
Pls confirm.
brgds,Ricardo
>>> "Stadem, Richard D." <[log in to unmask]> 21/01/2016 11:57
>>>
Defect Condition: Very minor bend in component leads necessary to meet
design requirements. Lead bend is less than 1 degree.
MRT Disposition; No Defect. While some leads display a very minor
lateral bend, there is no evidence of the bend extending into the point
where the leads enter the glass seal. There is no visible damage to
glass seals as seen at 30X magnification. Re-formed leads will not
affect form, fit, function, or reliability of CCA.
From: Ricardo Moncaglieri [mailto:[log in to unmask]]
Sent: Thursday, January 21, 2016 8:29 AM
To: Stadem, Richard D.; TechNet E-Mail Forum; Steve Gregory
Subject: Re: [TN] Terminal Bent More than 10% Diameter
Richard,
As per our customer contract constraints had to edit pictures in order
to erase marking, you will understand such a situation.
Steve,
Please would you be so kind to upload pictures? Your comments will be
appreciated.
Answering some issues, keep awaiting your considerations:
1) Terminal are round (not flat) and sideway bent no more than 1
diameter.
2) Manufacturer terminal gull wing preforming (knee, heel, connection
length area) was not modified just entire terminal was bent backward
(sideway) no more than one diameter and not repeat not just at seal.
3) Solder joint meets the J-STD-001 // 610 criteria (see picture) as my
consideration.
4) Terminal seal was not affected at all.
brgds,Ricardo
>>> "Stadem, Richard D."
<[log in to unmask]<mailto:[log in to unmask]
( mailto:[log in to unmask]:[log in to unmask]) >>
20/01/2016 18:44 >>>
You do not state in which direction the leads were formed in order to
meet all of the requirements listed in IPC-610 or J-STD-001, inwards,
outwards, up, down, and in the case of round leads, sideways. Technet
always strips all attachments, but Steve will probably post a link to
your picture for us if you send it to him directly, along with a gift
certificate to the local microbrewery. :)
I'm betting he will do it in response to this posting however.
But after reviewing both standards, I cannot find anything that says an
inward bend that is less than 90 degrees (where the heel is closer to
component body than the knee is) is a reject condition. I know that you
can form the leads such that the heel is further out from the body than
the knee, or greater than 90 degrees. Not sure about inwards.
Flat leads cannot be bent sideways, but round leads can. All of that is
pretty well covered, except for inward bends.
AS LONG AS;
* The lead is not bent in any direction within one lead
thickness from the point where it exits the body.
* There is sufficient strain relief (the bend radius
itself is at least one lead diameter or thickness, even though the
general bend angle is less than 90 degrees).
* There is no reduction of electrical clearance as a
result of the re-forming.
* There is no cracking of the lead as a result of the
forming, nor are there any gouges or scratches exceeding the posted
requirements in the standards.
* All of the lead-to-pad placement and solder joint
requirements are met.
* No stress was applied to the lead at the point where it
enters the body at any time during the forming or re-forming.
Then it should not pose any reliability issues. I would need to see a
good picture to state this for certainty.
dean
From: Ricardo Moncaglieri [mailto:[log in to unmask]]
Sent: Wednesday, January 20, 2016 1:30 PM
To: Stadem, Richard D.; Steve Gregory
Subject: Env: [TN] Terminal Bent More than 10% Diameter
Steve, Richard,
Any feedback from your side? Is will be to much appreciated from my
side....
brgds,Ricardo
>>> Ricardo Moncaglieri
<[log in to unmask]<mailto:[log in to unmask]<mailto:[log in to unmask]:[log in to unmask]
(
mailto:[log in to unmask]:[log in to unmask]:[log in to unmask]:[log in to unmask])
>>> 19/01/2016 17:45 >>>
Colleagues,
We are considering in a space (IPC class 3) application assembly, a
component similar to case T0 257 whose six gull wing terminals (three on
each side and their seals are vitrified) had to be blent more than 10%
(IPC J-STD-001 7.1.1) of their diameter (1 diameter) in order to be
mounted due to a wrong gerber design
The gull wing terminal zone shape well soldered on the pcb pad was not
modified, terminal was bent on its straight zone. Vitrified seal was not
affected at all. Thermal plane was fully soldered on thermal plane pad,
cause of that rework desoldering component could be more complicated.
Pcb base material is FR4.
Could anyone make me know his/her consideration as per background
experience on a case like this one about stress relief performance?
Could it have been affected to cause a solder crack under manufacturer
specified working conditions?
Matter here is that we have no enough time to run a stress analysis
(ciclic stress simulation on three axes) and reworking as I said upper
could be hazardous due to complexity of assembly.
Will appreciate too much your feedback/considerations.
Attached photo is x40 magnified.
Keep awaiting.
brgds,Ricardo
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