Thanks, Tim.  I have (what I think) to be the correct information from
Paulo.  Your reference to Table 9-1, Feature Location Tolerances, is not the
same as the Standard Fabrication Allowance, which is what I was looking for.
The Standard Fabrication Allowance is to be included in the formula for
calculating the Minimum Land Size of pads and the clearance space around
holes in the plane, not the Feature Location Tolerance.

Ray

----- Original Message -----
From: <Tim Easterling> <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, September 23, 1999 2:02 PM
Subject: Re: [DC] IPC Specs - Errors?


> The information you are looking for is in IPC-2222
> page 17 section 9.1.3 Clearance Area in Planes and
> table 9-1 which provides feature location tolerances
> for technology levels A,B,C.
>
>
>
>
> Tim Easterling
> Cadd Manager Commercial Engineering
> SCI Systems Inc.
> 8600 S. Memorial Parkway MS 200
> Huntsville, Al. 35802
> (256)882-4426 (ph)
> (256)882-4700 x4426 (voicemail)
> (256)882-4304 (fx)
> ----------------------------------------------
> Can you tell me on what page of IPC-2221/2222 the fabrication allowance
> appears on?  I do not have a copy, yet, but the people I have asked to
check
> say it is not in there.  I have IPC-D-275, which has it in Table 5-10 on
> page 64.
>
> ----- Original Message -----
> From: Gary Ferrari <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, September 22, 1999 6:43 PM
> Subject: Re: [DC] IPC Specs - Errors?
>
>
> > Ray,
> >
> > The IPC-2221/2222 makes quite a few improvements over the IPC-D-275,
> > especially in the standard fabrication allowance. I would suggest that
you
> > obtain a copy and evaluate these differences against your experiences.
Any
> > comments would be welcomed.
> >
> > Additionally, IPC standards committees are not closed to the public.
They
> > welcme all comments and data submitted for review. I suggest if you have
> data
> > that supports your concerns, that you submit them to the committee for
> > evaluation. The committee has scheduled a meeting at IPC Works in
> Minneapolis
> > on October 25th. I am sure they would like to meet with you and/or
discuss
> > your findings.
> >
> > Regards,
> >
> > Gary Ferrari
> > Executive Director
> > IPC Designers Council
> > 80-350-9300
> >
>