PCB Layout Tips

Index of contributed Howtos

  1. Printing holes with CIRCUIT MAKER or TRAXMAKER
  2. Express PCB to PDF
  3. Tango to Postscript
  4. PDF from Protel
  5. Current carrying capacity in PCB tracks

 

EAGLE

Many customers use Eagle pcb layout software. Eagle produces a very nice postscript file natively. To do so click the cad-cam manufacturing button. Select device PS. Deselect the fill pads button. Select the layers you want in copper (e.g.. Bottom, Pads, Via's) and process job. Click on the file button and choose where you want the postscript (*.ps) file file saved on your system. Email me the .ps.

For double sided boards you will have to do this twice:
Once with the Bottom layer and once with Top layer.

LINUX PCB

I use the linux package PCB by Thomas Nau and
recommend it highly. PCB makes a great .ps file from the print option.

Contributions by our clients

Printing holes with CIRCUIT MAKER or TRAXMAKER

Thank you Hennie for this info:
Go to file, Print, options, and under "Other settings"
Pad hole gide size = 0.8mm
Drill draw symbol size = 0.8mm
and make sure that "single layer pad hole" is selected
It should work!


Express PCB to PDF

Thank you Sutton for these instructions, James. 27 September 2006

I used the software called "ExpressPCB" version 5.6.0.

I have found the software on the web. Download it free of charge. The software is really free of charge and after installation no reminders came up as a 30 trial nor even any questionnaires to pay additional to have the full functionality.

ExpressPCB stores your hard work, component and copper lines lay out, in a PCB file format. The schematic side of this program saves the files in a SCH format file. This can be printed from the program it self.

Converting the PCB and SCH file to the Adobe Acrobat PDF format.

I have downloaded a PDF printer driver from the web called "Pdf995"

Link: http://www.pdf995.com/download.html

Downloads needed
1) Pdf995 Printer Driver (2.1 MB)
2) Free Converter . Version 1.1 (5.0 MB)
The to files needs to be installed on your system.

Now you ready to work.

Open your hard worked at file with ExpressPCB. Click print. On the form
that appears on top you have scroll down choice to where you would like to
print the document. Choose print to PDF995

The program will print/convert the normal choices given by the program for
the different layers to a PDF file. The file can then be read and printed as
any other normal PDF files.

Sutton

Tango to Postscript

These instructions from Johann Botha, Thanks.

  1. Click on Menu.
  2. Select Output.
  3. Select Plot/Print.
  4. Mark output options as required and Click OK.
  5. In drivers box select Postscript -- Printer Port should be set to file.
  6. Set scale 1:1
  7. Enter output filename eg bottom.ps and click OK.
  8. After output completed the "Output Plot/Print" box pops up again. Cancel it and return to the main menu.
  9. Check the postscript file with ghostview downloadable from adobe or try the online postscript viewer: http://view.samurajdata.se/
  10. Email the postscript file (bottom.ps) to cboards.
PDF from Protel

Here's a short description of how to generate a PDF layout from PROTEL. I used "Design Explorer 99 SE, Service Pack 6"

  1. First there needs to be a printer driver to which Windows can print and which generates a PDF file, mine appears as "Acrobat PDFwriter".
  2. When the PCB document is displayed, click "File - Print/Preview..."
  3. Select Tab "Browse PCBPrint" on the left-hand panel.
  4. Right-click on the first line which displays the usual printer driver, select "Properties..." and:
  5. under "Printer", select a PDF driver
  6. under "Print What" select "Standard Print"
  7. OK
  8. right-click "Multilayer Composite Print"
  9. "Layers": delete all except "MultiLayer" and ("Top Layer" or "Bottom Layer")
    "MultiLayer" is to be listed first to ensure the correct drawing
    sequence
    if it is not, select "MultilLayer" and click on "Move Up"
  10. "Components": all items to be selected
  11. "Options": tick "Show Holes"
  12. "Color Set": tick "Black & White"
  13. OK
  14. Clicking the tab "Process PCB" will update the layout
  15. to make the PDF file, click "File" - "Print Page" and follow the instructions.

Thanks for the opportunity for helping someone else with this
Regards - Erich

Current carrying capacity in PCB tracks

Thank you Deon for the info below:

Track Current Capabilities:

 

Copper Thickness (in micon)

 

35

70

Track width

Current

0.25 mm

0.59 A

0.98 A

0.33 mm

0.98 A

1.20 A

1.00 mm

1.20 A

2.68 A

2.00 mm

2.68 A

4.43 A

5.00 mm

4.43 A

8.61 A

10.00 mm

8.61 A

14.25 A

 

This is for a track of 25 mm long, at ambient temperature 25°C, allowing a track temperature rise of 20°C.

I used a "fancy" calculator - courtesy of circuitcalculator.com. Didn't have the text book with me, and can't remember from the top of my head. Had the internet handy. I also cross checked it with http://www.desmith.com/NMds/Electronics/TraceWidth.html and it checked
out.

"Always use at least two or more internet sources if you sort-of want to believe the Google results" - GJ Joubert.

Cheers

Deon

 

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