Hi Gabriele - the IPC BTC Voids task group  is coordinating with the
IPC-7093 specification committee so that both specifications are in sync.
Just as the JSTD-001 has the BGA void requirements and the IPC-7095
specification contains the BGA void design aspect/assessment guidance, the
JSTD-001 and the IPC-7093 specification will have a similar relationship
for BTC voiding.

Dave

On Mon, Mar 5, 2018 at 11:26 AM, SALA GABRIELE <[log in to unmask]> wrote:

> Many Thanks Dave,
>
> are the BTC Task Group  (5-21h ? ) doing same void limits assessment for
> the coming  IPC-7093 A Review ?
>
> Best Regards
> Gabriele
>
> -----Messaggio originale-----
> Da: TechNet [mailto:[log in to unmask]] Per conto di David Hillman
> Inviato: domenica 4 marzo 2018 01:54
> A: [log in to unmask]
> Oggetto: Re: [TN] Bottom Termination Components (BTC) Voiding Limits
>
> Hi Wayne - you have good timing with your question as I can give you the
> latest info from the IPC committee meeting last week. The JSTD-001
> committee had a comment submitted asking for void criteria for BTCs.  A
> small task group with global representation from several industry product
> segments was formed to review the issue. We reviewed the issue with data
> resources from consortia, IPC and SMTA resources.  We had one very specific
> conclusion: Any void criteria that would be put into the JSTD-001
> specification would be addressing solder joint integrity only. Many BTCs
> have either thermal or electrical functional needs which is a design issue
> that should be addressed during the product design phase.  Here is what the
> task team responded back to the JSTD-001 committee with:
>
> "The JSTD-001 QFN Void Criteria task group recommends that a "request for
> data" be issued as a review of the current available industry data was
> found to not be sufficient to establish a data based maximum void criteria
> for solder joint integrity. The voiding criteria requirements pertaining to
> the functionality of a QFN or other Bottom Terminated Components (i.e.
> thermal or electrical performance) are a design function and not part of
> the IPC-JSTD-001 specification scope. The "request for data" responses
> should be sent to the QFN Void Criteria task group by October 31st, 2018 so
> that they can be reviewed prior to the 2019 IPC JSTD 001 APEX committee
> meeting. The  JSTD-001 QFN Void Criteria task group will provide a void
> criteria recommendation to the IPC JSTD 001 committee based on the data
> submissions at the  2019 IPC JSTD 001 committee meeting."
>
> The void number you listed - especially the 25% - have little to no
> technical data justification in terms of solder joint integrity.The
> JSTD-001 BTC Void task group is looking for DOE/test/investigation data
> and there will be a recommendation to the JSTD-001 committee for review at
> the
> 2019 committee APEX meeting. I understand that seems like a long time but
> any criterial that is put into the JSTD-001 specification must be done
> based on data as those requirements results in costs to the industry.
>
> A number of OEMs verbally committed to providing BTC void data to the
> JSTD-001 BTC Void task group so I am confident the issue will be resolved
> within the year. If anyone has  data they would like  to submit to the task
> group, please send it to me and I'll make sure it is included in the data
> review.
>
> Let me know if you have any additional questions.
>
>
> Dave Hillman
> IPC JSTD-001 BTC task group lead
> Rockwell Collins
> [log in to unmask]
>
>
> On Sat, Mar 3, 2018 at 6:18 PM, Wayne Showers <
> [log in to unmask]>
> wrote:
>
> > I do not know of an IPC criteria on this.  I have seen 25% (The BGA
> > criteria) cited, but this is not, to my knowledge accurate.
> > The limits I have used in the past are 50% Coverage with no void
> > exceeding 15% in the center and no more than 10% anywhere else.
> > I also used a 70% Coverage and 10% Void criteria for a very heat
> > sensitive application.
> >
> > Question 1: Is there now a citable IPC criteria? and if NO, Question
> > 2: What are some of this groups recommended criteria?
> >
> > Thanks and Regards, Wayne Showers, NPI/Technical Manager, 4Front
> > Solutions
> >
>
>
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