I have just measured the output of a unit. I used a previous PCB I had designed that used a TO220 device.
That used both round and square pads. From module editor the pad sizes were 0.07" for both the square and round. I printed this as a postscript file to the printer, (I use a OKI C5400) I then scanned the area around the TO220 at 1200dpi using the flatbed. Counting the pixels I get 86 pixels across both the square and round pads. That works out at 0.0716" which is bang on correct as far as the measurement method goes. So in the postscript output the pad sizes are correct as stated in the module editor. I agree that the pads do LOOK a bit thin and small, but that's how they are designed. If you can do the same sort of measurment you could find out if your output is really wrong. Andy On Wed, 15 Apr 2009 19:27:58 -0000 "Jos" <[email protected]> wrote: > > You are right Andy, > I find the dimensions for the track also to be a little thin. > > The print is mate for true scale to a PDF printer in the printer setup from > Win XP. > > Here at home I print directly to a laserjet 5si, also in true scale. > I mirror the copper, as you might have noticed, for printing on transparent. > Then the toner makes direct contact with the copper of the PCB and light will > not spill over. > > But everything is a bit undersized. > I used to work with Ultiboard some 10 years back. > > Jos PA0AMX > > --- In [email protected], Andy Eskelson <andyya...@...> wrote: > > > > The pads look fairly normal to me but... > > > > How did you print them out, be careful about this as there are several > > printing options. There are options for a rough print, useful for > > checking, but the dimensions will not be exact. There is an exact print > > option which you would use for photo resist films. Under the print > > options. > > > > There are other options to print under the plot menu either the full size > > drill or just a drilling mark. > > > > For things like the one pin connector which I think you have used, I find > > that the defined drill size leaves far too little copper, so I always > > change that. I also plot to postscript for the main output and set the > > drill to just be a point rather than full size as for home workshop use > > that provides a nice centre point for the drill bit to follow. > > > > I don't get the effect you see here, so perhaps it's a display/grid size > > thing. > > > > As a general observation I would be inclined to beef up the track widths > > you are using. You will find that they are very thin, and in my opinion a > > bit too thin for a 1A regulator. > > > > Andy > > > > > ------------------------------------ > > Please read the Kicad FAQ in the group files section before posting your > question. > Please post your bug reports here. They will be picked up by the creator of > Kicad. > Please visit http://www.kicadlib.org for details of how to contribute your > symbols/modules to the kicad library. > For building Kicad from source and other development questions visit the > kicad-devel group at http://groups.yahoo.com/group/kicad-develYahoo! Groups > Links > > >
