PCB tolerances

Hi,

Is a tolerance of 0,05 mm for holes on a PCB normal or is this a
problem to achieve?

thanks,

rokanon

 

[Larry Brasfield]

<rondo@mcmail.net> wrote in message news:dj5jm0di2sli4m004bh6h7vu4mbplsgpk8@4ax.com...

Hi,
Hi.

Is a tolerance of 0,05 mm for holes on a PCB normal or is this a
problem to achieve?

If that is hole size, it will be difficult to achieve. Even twice that
tolerance would be tighter than is usually specified for ordinary
FR4/copper laminated PCBs.

If that is tolerance on position of the edges, it is even further from
practicality. Drills tend to wander off vertical as they go thru a
stack of boards.

You should consult a few vendors on practical tolerances.
For example:
http://www.4pcb.com/fast_design_quote_online_pcbs_tolerances.htm

thanks,
You're welcome.

rokanon

--
--Larry Brasfield
email: donotspam_larry_brasfield@hotmail.com
Above views may belong only to me.

 

On Sun, 10 Oct 2004 16:51:17 -0700, "Larry Brasfield"
<donotspam_larry_brasfield@hotmail.com> wrote:

rondo@mcmail.net> wrote in message news:dj5jm0di2sli4m004bh6h7vu4mbplsgpk8@4ax.com...
Hi,
Hi.

Is a tolerance of 0,05 mm for holes on a PCB normal or is this a
problem to achieve?

If that is hole size, it will be difficult to achieve. Even twice that
tolerance would be tighter than is usually specified for ordinary
FR4/copper laminated PCBs.

If that is tolerance on position of the edges, it is even further from
practicality. Drills tend to wander off vertical as they go thru a
stack of boards.

You should consult a few vendors on practical tolerances.
For example:
http://www.4pcb.com/fast_design_quote_online_pcbs_tolerances.htm

thanks,
You're welcome.

rokanon

Thanks for your info,

The problem is that the automative world is ruled by the mechanicals
and it very hard to convince them about tolerances.

rokanon

 

[Schöön Martin]

rondo@mcmail.net writes:

The problem is that the automative world is ruled by the mechanicals
and it very hard to convince them about tolerances.

rokanon

Hmmm... what make do you work for? Sounds like something I should
avoid next time I buy a car

A more serious note: Several years ago I read a very interesting
article on tolerances used in various parts of the automotive
industry. This article was published in one of IEEE's magazines.
Parts as different as door hinges and crankshafts were treated.
What made it interesting was the part that correlated part tolerances
to owner experience.

--
========================================================================
Martin Schöön <Martin.Schoon@ericsson.com>

"Problems worthy of attack
prove their worth by hitting back"
Piet Hein
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