I like FreePCB (www.freepcb.com). I do boards sporadically (months
apart) so the program is simple enough to pick up again after long
periods of absence. There are NO cripples.
From their blurb on the web site:
* 1 to 16 copper layers
* Board size up to 60 inches by 60 inches
* Uses English or metric units (i.e. mils or mm) for most functions.
* Footprint libraries courtesy of Ivex Design International, PCB
Matrix and the IPC.
* Copper fill areas
* Footprint Wizard and Footprint Editor for creating or modifying
footprints
* Imports and exports PADS-PCB netlists
* Exports extended Gerber files (RS274X) and Excellon drill files
* Design rule checker
* Autosave
Pre-viewing the Gerber files
A) After generating the Gerber files, I check them with the free version
of GC-Prevue.
(
http://www.graphicode.com/Download_GC-Prevue_and_Free_Trials). From
this program I laser print (HP4Si) on glossy paper pages from
magazines. (Thanks ever so much to the Homebrew list for this tip. It
works better than any of the many photo glossy paper I ever tried.)
B) I just became aware of another program, ViewMate with "smart DFM"
(
http://www.pentalogix.com/) that appears to be just as capable -- but
I haven't tested it through the whole process of printing.
C) There are also other Gerber viewers that I haven't tried
http://www.designspark.com/knowledge/gc-prevue-gerber-viewer
http://www.everythingpcb.com/p17596.htm
Generating the netlist:
A) I generate netlists from a very old copy of ORCAD.
B) I have briefly tested Suigyodo Schematic
(
http://www.suigyodo.com/online/e/index.htm) and it seems to work fine
and is capable of generating compatible netlists including footprint
names to be included in the netlist.
C) Another route is to use LTspice from Linear Technology. This one
exports a netlist that requires some minor editing to make it really
useful as LTspice does not have a "package" field so the case sizes to
select the footprint are not included in the netlist.
Additional pluses:
FreePCB is a very capable PCB editor and data save files are ASCII.
This is very handy as I have taken NC files from a client, and imported
them to the board outline with only minor editing to yield a very
complex board with multiple curved edges and holes that have to be
placed exactly. Because FreePCB only does 90 degree arcs in the board
outline, the NC file is made of a lot of small straight line segments
(typically about 10 mills). Works for me.
I have no vested interest in any of the companies mentioned above, other
than appreciating very much the time people have spent developing fine
freeware software packages other than ORCAD that was purchased before I
retired. (And as a side note, FreePCB is much more stable than the
early PCB layout packages ORCAD sold for bunches of money -- so paying
for a commercial product doesn't always guarantee better performance.)
Regards,
Charles R. Patton