Preparing CAD Drawing for Printed Circuit Board Design

The Vectorworks CAD program that is used here starts up in a mode suitable for architectural drawings. The scale and snap grids must be changes to make it suitable for a PCB layout. Complete the following steps.

• You will use a standard 8.5"x11" sheet (letter size). It is recommended but not absolutely necessary to change the page to landscape; menu File ==>Print Setup....select Landscape
• The sheet normally opens at a 1:48 scale suitable for buildings. To establish a 1:1 (actual size) scale ; menu Organize==>Layers....select Scale....select Engineering 1:1, OK,OK. (It is important to do this before any other layers are created. If there is more than one layer at this point then each layer may need to have its scale changed.)
• We will work in S.I. units. The sheet comes up in Imperial. To change to S.I.. ; menu Page==>Units...pull down 'Feet and Inches' to Millimeters, OK (You may wish to change the Rounding Decimal to two significant digits.)
• Many electronic components (including most I.C.'s) have their connections separated by 0.1 inch (2.54 mm) (or some multiple of 0.1 inch) spaces. It is helpful to establish a grid so that components 'snap' to this standard. To complete this menu Page==>Set Grid...set Snap Grid X to 2.54 mm and Reference Grid X to 25.4, OK
• The next step is optional for more advanced boards and senior students. However it does not hurt to establish layers even for your first board and only use the circuit layout layer.
  • You should establish some Layers. As a minimum set up four layers named, construction, circuit layout, parts, and top screen.
  • menu Organize==>Layers... click New... set Name to circuit layout, OK, click New... set Name to parts, OK, click New... set Name to top_screen, OK highlight Layer-1 under Layer, then set Name to construction, OK.
• There are two things that you should do to observe your lines properly. First ; menu File==>Preferences==>Vectorworks Preferences....tab Display, check Zoom Line Thickness, OK. (this will allow you to see the thickness of lines correctly when you zoom in. Secondly ; menu Pallet==> Attributes, on the line style box on the Attributes Pallet choose Set Thickness..., check mm, OK.

You may wish to save the document now (better yet save as a template under the file menu), it may be opened as a template for future similar drawings.