Hi Richard - the JSTD-001 void criteria is focused on the
assembly/manufacturing folks and the IPC-7093 is focused on the design
folks so both aspects of the issue are covered. The JSTD-001 will/does
specifically points to the IPC-7093 specification to make sure both aspects
of the issue are covered and coordinated.

Dave

On Tue, Mar 6, 2018 at 7:06 AM, Stadem, Richard D <[log in to unmask]>
wrote:

> Wayne, thank you for the effort and the information you are working on. It
> will prove valuable to the industry as a whole.
> Dave, I understand this information from the group will end up in the
> proposed BTC guidelines, but that is primarily going to function as a
> manufacturing process guideline. Do you think some of the pad layout
> information (stencil design info, etc) should be also directed into one of
> the Design standards as well? What good does it do to tell the MEs what
> percent of voiding, etc, is acceptable, but not tell the Design group how
> to avoid the voids in the first place?
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Showers
> Sent: Monday, March 05, 2018 3:51 PM
> To: [log in to unmask]
> Subject: Re: [TN] Bottom Termination Components (BTC) Voiding Limits
>
> Dave et al,
> You can add me to the list of companies that will provide voiding data.  I
> am data mining variations of the print pattern to reduce voiding and I am
> in the process of marrying up stencil design to void and fill percentages.
>
> I can echo the voiding request from Blackberry.  The original request was
> 90% coverage and no more than 3 voids with no single void greater than 5%.
> Even to get to the 70%, I ended up using a custom solder slug and still had
> voiding due to via in pad.
>
> I would like to see a standard that reflects something similar to the
> following:
> Class 1: Undefined
> Class 2: Shall be 50% coverage with no single void exceeding X% or as
> defined by customer or part manufacturer.
> Class 3: Shall be 70% coverage with no single void exceeding X% or as
> defined by customer or part manufacturer.
> Note 1: Customer Requirements supersede
> Note 2: Manufacturer Recommendations/Requirements supersede Note 3: VIA in
> Pad and other design factors shall be considered and evaluated if criteria
> cannot be met.
>