We at DSCC also feel that standard default tolerances should be included in
the design documents such as IPC-2221.

R. Lowell Sherman
DSCC-VQE
614-692-0627

> -----Original Message-----
> From: Rene Martinez [SMTP:[log in to unmask]]
> Sent: Friday, September 22, 2000 10:12 AM
> To:   [log in to unmask]
> Subject:      Re: [IPC-600-6012] End Product Requirements for Board
> Thickness Tolerances
>
> I also think a default is in order.  Especially because the designers need
> to know the limitations of how tight of a tolerance can be called out when
> you add inherent tolerances of copper,laminate, plating, etc.
>
> -----Original Message-----
> From: Jih Yuan [mailto:[log in to unmask]]
> Sent: Friday, September 22, 2000 5:47 AM
> To: [log in to unmask]
> Subject: Re: [IPC-600-6012] End Product Requirements for Board Thickness
> Tolerances
>
>
> John, From an OEM perspective, I think it's always good to have a default
> value. That's what the industry standard is about.  Jih
>
> -----Original Message-----
> From: IPC-600-6012 Mail Forum [mailto:[log in to unmask]]On Behalf Of
> John Perry
> Sent: Wednesday, September 20, 2000 5:37 PM
> To: [log in to unmask]
> Subject: [IPC-600-6012] End Product Requirements for Board Thickness
> Tolerances
>
>
> Hello Everyone,
>
> IPCWorks 2000 has come and gone.  Ready for Expo in Anaheim?  Sheez, are
> you
> kidding?
>
> As participants in the IPC-6012 and IPC-A-600 groups, many of you have
> also
> been involved with the IPC-2220 design series, and many of you may recall
> the ancient IPC-D-300G Printed Board Dimensions and Tolerances document.
> This old dinosaur was recently replaced by the IPC-2615, thankfully
> without
> the outdated end-product requirements such as bow and twist and annular
> ring, all of which have been updated through the years where they belong -
> in the design and performance specs.
>
> One, however, hasn't been transferred to the appropriate requirements
> documents, and I wanted to make sure that it was an intentional exclusion.
> IPC-D-300G used to provide tolerances for board thicknesses.  We don't
> have
> any applicable tolerances for this in any of the other spec.  Sure,
> IPC-4101
> does provide tolerances for laminate materials (Table 7) , and IPC-6012
> and
> IPC-A-600 provide thicknesses for foil plus plating (under review now as
> we
> speak!), but did we intentional avoid the transfer of nominal thickness
> tolerances for finished rigid boards to the design and performance series
> of
> documents that we currently use for boards?  Should we point people to the
> use of IPC-4101 in conjunction with the IPC-6012?  As always, your input
> is
> much appreciated.
>
> Best Regards,
>
>
>
> John Perry
> Technical Project Manager
> IPC
> 2215 Sanders Road
> Northbrook, Il 60062
> 1-847-790-5318 (P)
> 1-847-509-9798 (F)
> [log in to unmask]