icegray wrote:
> You think autoroter is useful when using CSP, BGA products?

I've never used an autorouter that can handle the dense routing that
BGA's create. I've even given hand routed netlists to others to
autoroute
only to have the autorouter create a mess of the space with vias and
generally not even be able to route the existing design (Cadence router
last year on a PC104+ design with BG560, several large QFP/TSOP
packages and misc parts. that was already hand routed with PCB).

Routing BGA's, especially those with more than 500 pads, is very
difficult
to do manhattan, and generally requires establishing "flows" of traces
in
both dimensions to connect to cpus, memory and connectors which have
high
pinouts. This requires a lot of placement thought.

The big advantage of hand routing BGAs is choosing pins/pads to route
easy, not picking pins/pads arbitrarily and hoping the pins swap
function
(if any) can get it right.

Whether you can or should use an autorouter is not an easy question to
answer. If you are using CSP and BGA parts, you should (usually) break
them out yourself and let the autorouter run after constraining it (fix
nets you do not want ripped up, such as power islands on otherwise
signal layers, or certain signals that should not move for one reason
or another).

So an autorouter can be useful where there are many non-critical
signals or many signals where you can set specific rules (and the
autorouter obeys them).

Much also depends on the signalling speeds, as autorouters tend to be
pretty useless at really high frequencies (such as InfiniBand, PCI
Express, Fibre channel etc). It *can* be a boon for point to point
memory (but a bane for distributed systems as it is difficult to set
the rules precisely in most packages).

Cheers

PeteS

You think autoroter is useful when using CSP, BGA products?

air_bits@yahoo.com wrote:

> 
> icegray wrote:
>> Hi all,
>> Which PCB program does Professional use?
>> PCAD is better than ORCAD and PADS or which one is better??????? I have
>> got ORCAD experience and I think ORCAD is not comfortable at advance
>> PCB. What do you think about PCB programs?
> 
> I've been using an open source tool for several years called pcb which
> is
> integrated into the gEDA project.
> 

The other open source tool you could consider is Kicad. Runs on Linux and
Windows. look for it here:

http://www.lis.inpg.fr/realise_au_lis/kicad/index.html

Ian

icegray wrote:
> Hi all,
> Which PCB program does Professional use?
> PCAD is better than ORCAD and PADS or which one is better??????? I have
> got ORCAD experience and I think ORCAD is not comfortable at advance
> PCB. What do you think about PCB programs?

I've been using an open source tool for several years called pcb which
is
integrated into the gEDA project.

    http://www.geda.seul.org/

    http://sourceforge.net/projects/pcb

If you pull the sources from sf.net for pcb, you might want to ignore
the
latest release pcb-20050609 which was their first stab at using GTK2
for the back end (it's horribly slow for anything other than trival
layouts)

Previous releases, pcb-20050315 and earlier and built on std X librarys
and have crisp performance on even slow machines. Binaries have been
build under cygwin and gcc for windows machines and perform well for
those
that are not using a UNIX, Linux, FreeBSD or OS-X Mac desktop.

What programs do professionals use? All of them, depending on the needs
of the company. I have used most of the usual culprits, and it comes
down to just what features you need. If you don't need 30+ layer
boards, you probably don't need Cadence or Mentor tools (apart from
their cost anyway).
Eagle, Protel, PCad and others can do most things in layout unless you
need really advanced features.

So my questions would be (for a start, anyway)

Are you dealing with 1000s of nets?
Do you need high multilayer support?
Do you need integration with a signal analysis tool (such as
SpectraQuest or PSpice)
Do you need to set advanced routing rules? (e.g. Multiple nets for
differential pairs)
What level of autorouting do you need? (if you need it at all)

The answers to those will help determine what package you really need.
There was a thread on this in S.E.D not so long ago - the further up
the toolchain you go, the steeper the learning curve.

Cheers

PeteS

codic <e@e.e> wrote:
> On Thu, 10 Nov 2005 21:09:50 -0800, "Marios Lazos"
><marioslazos@hotmail.com> wrote:
>
>>
>>"fred*" <fred@mail.com> wrote in message 
>>news:43737fd2$0$6659$8fcfb975@news.wanadoo.fr...
>>>
>>> "icegray" <usrdr@yahoo.co.uk> a &#4294967295;crit dans le message de
>>> news:1131638011.906306.240550@g43g2000cwa.googlegroups.com...
>>>> Hi all,
>>>> Which PCB program does Professional use?
>>>> PCAD is better than ORCAD and PADS or which one is better??????? I have
>>>> got ORCAD experience and I think ORCAD is not comfortable at advance
>>>> PCB. What do you think about PCB programs?
>>>>
>>>
>>> Protel DXP is good but BIG price..
>>>
>>> for very low budget, have a look (and try it) at Rimu PCB, very nice for 
>>> the price :
>>> http://www.hutson.co.nz/
>>>
>>>
>>
>>We use PCAD in my company and its excellent for professional use.Personal i 
>>prefer PROTEL because i feel more flexible for my projects.Finaly these two 
>>programms are the best choice for a prof use.
>>
>>Marios Lazos 
>>
>
> Do you know if PCAD supports scripting? I have used Eagle for some
> years now, and one of the things I love in it is its scripting
> capabilities. Very useful to define rectangular or polar arrays of any
> structure. There are other things that I don't like so much, though,
> such as copying/moving objects across libraries.

It does but I've no idea how useful it is, coz I've never used it.  There is
a macro record facility that records files like:

SchMacro sch_default 'Created by LCAPUA on Tue Feb 09 15:41:43 1999
	SendKeys "{ALT+U}{Z}{Tab}{A}"
	SendKeys "{SHIFT+N}{O}"
	SendKeys "{T}{E}{SHIFT+P}{A}"
	SendKeys "{D}{Tab}{N}{O}"
	SendKeys "{T}{E}{P}{A}"
	SendKeys "{D}{Period}{E}{X}"
	SendKeys "{E}{Tab}{Tab}{Tab}"
	SendKeys "{Tab}{Tab}{Enter}"
End

which I guess you can edit (That one was one of the supplied ones).  
There's also a programming interface which lets you write applets in
C or VBasic to extend the program - it can interact with the running 
programs and the loaded schematics and PCBs.  As I said, I've used
neither method, although I have resorted to editing the ASCII data
files with a text editor, the syntax is pretty easy to infer and
it's a quick way of making lots of some types of changes.

I like PCad, but I'd have to admit I've not used anything else.  It
can be annoying, though, in that a PCB layout package is really just
an enhanced drawing package (eg AutoCad) but it doesn't let you do
a lot of fairly primitive operations like arbitrary rotations, 
mirroring about abitrary lines, scaling and stretching (scaling
on only a single axis).  However, it's perfectly adequate for PCB
layout, but just fails to meet it's full potential.  

It's quite expensive though, for some values of expensive.  Alternatively
it's quite cheap for other values of cheap.  It depends on your
perspective.  Of the top of my heaad it was about UK&#4294967295;1500 or so
per seat and another 500 per annum for maintenance, but I could
be confusing it with one of the many other software packages we 
have :-)

-- 
Nobby

Try ExpressPCB . It is free.
 www.expresspcb.com

On Thu, 10 Nov 2005 21:09:50 -0800, "Marios Lazos"
<marioslazos@hotmail.com> wrote:

>
>"fred*" <fred@mail.com> wrote in message 
>news:43737fd2$0$6659$8fcfb975@news.wanadoo.fr...
>>
>> "icegray" <usrdr@yahoo.co.uk> a &#4294967295;crit dans le message de
>> news:1131638011.906306.240550@g43g2000cwa.googlegroups.com...
>>> Hi all,
>>> Which PCB program does Professional use?
>>> PCAD is better than ORCAD and PADS or which one is better??????? I have
>>> got ORCAD experience and I think ORCAD is not comfortable at advance
>>> PCB. What do you think about PCB programs?
>>>
>>
>> Protel DXP is good but BIG price..
>>
>> for very low budget, have a look (and try it) at Rimu PCB, very nice for 
>> the price :
>> http://www.hutson.co.nz/
>>
>>
>
>We use PCAD in my company and its excellent for professional use.Personal i 
>prefer PROTEL because i feel more flexible for my projects.Finaly these two 
>programms are the best choice for a prof use.
>
>Marios Lazos 
>

Do you know if PCAD supports scripting? I have used Eagle for some
years now, and one of the things I love in it is its scripting
capabilities. Very useful to define rectangular or polar arrays of any
structure. There are other things that I don't like so much, though,
such as copying/moving objects across libraries.

Best.