I think you might be looking for IPC-2222 section 9.1.5 conductive pattern
feature location tolerance.
In a table (9-1) producibility levels are assigned to tolerances applied to
the nominal dimension chosen for the location of lands connector contacts
and conductors in relation to the datums, including master pattern accuracy,
material movement, layer registration and fixturing.
Note: this standard applies to rigid organic printed boards.
Guy Ramsey
Senior Lab Technician / Instructor
E-Mail: [log in to unmask] <mailto:[log in to unmask]>
Ph: (610) 362-1200 x107
Fax: (610) 362-1290
-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of d. terstegge
Sent: Wednesday, July 11, 2001 11:37 AM
To: [log in to unmask]
Subject: Re: [TN] Pattern to Pattern Tolerance
Hi Scott,
About a year ago I asked the same question on Technet and I was suprised
that I received no answers. I was even more surprised that most of our
pcb-suppliers could not give me any specification for feature to feature
tolerance, in spite of the fact that this is can be an extremely important
parameter for assembly (especially for large boards with fine pitches).
Finally I found out that 0.05% is a typical value for pattern to pattern
tolerance, which means that there can exist a 0.15 mm tolerance over a 300
mm distance !!
Stretch and shrink can occur during manufacturing of the board, and is not
only caused by artwork imaging or geber plotting.
Kind regards,
Daan Terstegge
SMT Centre
Thales Communications
Unclassified mail
Personal Website: http://www.smtinfo.net
> ----------
> From: Buscomb, Scott[SMTP:[log in to unmask]]
> Reply To: TechNet E-Mail Forum.;Buscomb, Scott
> Sent: Monday, July 09, 2001 6:07 PM
> To: [log in to unmask]
> Subject: [TN] Pattern to Pattern Tolerance
>
> I am looking for the standard industry locational tolerance of copper
> feature to copper feature on a single sided PCB. Since PCB fabrication is
> a
> photographic process, I am assuming it is a function of gerber plotter and
> artwork imaging.
> TIA,
>
> Scott Buscomb
>
> --------------------------------------------------------------------------
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