Electronics > PCB/EDA/CAD

PCB Stackup Planning and Materials Selection Tools

<< < (3/3)

Uky:
That is indeed true. In most cases, the customers I work for has a long term relationship with "their" board manufacturer
which saves me the hassle from searching for stackups myself. When the assignment is about to start; i approach the
manufacturer and we establish a dialog which saves me and the board manufacturer from unneccessary extra work.

 :)

nctnico:
That would be so nice... Some of my designs have been produced by at least half a dozen different manufacturers and at one point a PCB manufacturer did manage to mess up the production of a board for a rather large production run. No happy faces and lots of finger pointing. BTW, it is interesting to see how much variation there is in trace widths between various PCB manufacturers based on the exact same layout. So even with a well defined stackup, etc there will be a large tolerance in the actual impedance of the traces.

Damperhead:
This eBook can increase your knowledge of stack-up design. The information is relevant especially if you are dealing with hi-speed links like high-speed Ethernet PAM4 protocols, including 25GE, 50GE, 100GE for example.

http://i-007ebooks.com/my-i-connect007/books/printed-circuit-designers-guide-stackups-design-within-design/

asmi:

--- Quote from: nctnico on June 01, 2023, 05:37:09 pm ---That would be so nice... Some of my designs have been produced by at least half a dozen different manufacturers and at one point a PCB manufacturer did manage to mess up the production of a board for a rather large production run. No happy faces and lots of finger pointing. BTW, it is interesting to see how much variation there is in trace widths between various PCB manufacturers based on the exact same layout. So even with a well defined stackup, etc there will be a large tolerance in the actual impedance of the traces.

--- End quote ---
To help with that, if I know that the PCB might end up being manufactured all over the place, I target an impedance value closer to a lower bound of impedance tolerance window in my eCAD, this creates traces which are a bit wider than ideal, and so manufacturer can make them narrower if required for his process/stackup. This is OK because you can always make traces narrower, but often you can't make them wider without violating spacing and/or increasing risk of problems related to crosstalk.

Navigation

[0] Message Index

[*] Previous page