general tolerance of a PCB, both of FR4 and metal core

[limct]

Hi all,
Can someone shed some light on this for me.
Q: what's the general tolerance (pad size, distances, picthing..etc) of a Gerber file converetd PCB, both of FR4 and metal core type?
Many thanks!

Best regards,
ct

 

[MacGyverS2000]

I'm not sure the question makes a lot of sense... the tolerance is whatever the manufacturer is able to achieve above the specs you set. I could make an FR4 board with tolerances on pad sizes of 100 mils using a permanent marker and an etch tank, but a board house might have a tolerance of 1 mil.


Dan - Owner

http://www.Hi-TecDesigns.com

 

[Comcokid]

You need to talk to several PCB manufacturers. Many have on their web sites a list of general specs for trace/space, minimum hole size, etc. But these guidelines can be exceeded for additional cost and lower yield.

 

[IRstuff]

Moreover, tolerances of finished parts are a function of the process control imposed by the manufacturer. I, doing parts in my garage, will have a different level of process control compared to a commercial shop.

If you're asking what the state of the art is, look at a high-end video card like an Nvidia Ge 7 series board:

http://www.nvidia.com/page/geforce_7950.html

It's got a 1GB memory with 512-bit effective memory I/O

TTFN