Matt
I am a circuit/system designer who is is self-taught on PCB design.  I
design my own pcb's because I design portable electronics and the
flexibility of placing the components at the time I'm designing the
electronic package, etc. gives me some incredibly efficient packaging
results.  I only design portables.  I recently used Protel Successfully to
route a Pentium-III Portable mainboard with 12 layers and several BGA
devices.  The first spin of the board booted Windows.  If I were to contract
out to a pure PCB designer, then I would have much less flexibility in the
overall design, electronic, mechanical, and interconnect.  SO I do it myself
first, then contract out for production once I get the design up and
running.

I have had some serious battles with Protel software.   But I have set up
and run the autorouter, and once when I sent a board out and had the
SPECCTRA autorouter run, the difference between the two was not as great as
I would have guessed.  Remember, that's from a layman in terms of PCB
routing efficiency.

Personally, I am going to give the next release of Protel a long, hard look.
I have resisted the move to PADS because of the expense and learning curve -
I have been using Protel for several years.

-----Original Message-----
From: Matt Polak [mailto:[EMAIL PROTECTED]]
Sent: Monday, January 21, 2002 9:51 AM
To: Protel EDA Forum
Subject: [PEDA] Autorouting or manual routing, or both?


        Hey folks,

        It seems that a majority of you are doing some very dense,
high-speed
layouts with 4-6 layers being quite a common occurrence. I'm just wondering
how much you typically route by hand, and how much you let the auto-router
whack away at.

        Being primarily self-taught in the ways of Protel, and with the help
of a
few 'older school' engineer friends here and there, I've done a number of
successful design layouts thus far, but these have been relatively simple 2
and 4 layer designs without many small-pitch/high pin-count devices. I'm
moving more towards laying out more high-speed designs in the near future
where a lot of stuff needs to be fit into a small place, and all connect
together without traces and vias meandering all over.

        When I look at sample six layer boards (such as the 5407 EVM
reference
design Motorola has released) the bussing and interconnects are extremely
elegant and efficient in appearance. For fun, I unrouted the 5407 board and
then let the autorouter chew on it. It immediately made 'via swiss-cheese'
out of the board and created little more than a large mess. I'm GUESSING
quite a bit of these sort of designs are laid out by hand, or at least
pre-routed to give the auto-router a sense of direction?

        Can anyone offer some basic pointers to getting started into
planning and
laying out PCBs for multi-layer, high-speed designs such as these? I have
no idea where one would really even start with something like this. It
seems most of the important knowledge gets passed directly from engineer to
engineer; there are certainly no university classes (that I know of,
anyway) that teach you how to lay out a dense, 6 layer board. :/ I
appreciate the patience and wisdom of those who remember once being where I
am now, who are willing to take the time to pass some of the tips and
tricks down the engineering family tree.

        Thanks again for any pointers anyone can provide (either through the
list,
or privately.)

Best regards,
-- Matt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* To post a message: mailto:[EMAIL PROTECTED]
*
* To leave this list visit:
* http://www.techservinc.com/protelusers/leave.html
*
* Contact the list manager:
* mailto:[EMAIL PROTECTED]
*
* Forum Guidelines Rules:
* http://www.techservinc.com/protelusers/forumrules.html
*
* Browse or Search previous postings:
* http://www.mail-archive.com/proteledaforum@techservinc.com
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Reply via email to