Copper Connection - Connecting the Dots

• Use the line tool in Vectorworks to join the electrical connections.
• Try to minimize any wires crossing. If this occurs you may need to locate two pads and provide a wire jumper. This can often be avoided by locating wires under passive components or under I.C.'s. You may wish to move components.
• If a trace width is too small it may make an open circuit when it is fabricated or melt from too much current. If too large short circuits may develop and locating the wiring may become difficult. Use the following guidelines to determine the thickness of the wire traces.
  • Generally a line thickness of 0.5 mm works well. You should check that no more than 0.5 Amperes of current flows through such traces. If you cannot or the current is too high then;
    • You may use smaller traces if required but if they are too thin you may need to be very careful and have lots of practice making PCB's. (It may be possible to make traces as thin as 0.15 mm thick) I have seen successful traces laid out between pads of an I.C.
    • You should check the width of the line to be sure the copper is wide enough to handle the current. You should be safe if you multiply the current (in Amperes) by a factor of 1.3. This will give you the minimum thickness of the trace you should need (in mm).
• Checking
  • It is very important to check your work when the copper connections are completed. It is a small job at this point to change a wire or pad location or connection, but it is a big job once the PCB has been etched and drilled.
  • Checking should be done in two steps;
    • Step 1 - Print out your pcb trace and your schematic diagram. Using a highlighter, marker or coloured pencil check each connection in the schematic diagram and colour it in, then colour in the corresponding connection on the PCB trace. For example if the pin of a particular resistor connects to the top of a diode, then colour in each wire trace on the schematic and the PCB layout at the same time. Continue until all the connections have been coloured in on both the schematic and the PCB trace.
    • Step 2 - Use the PCB trace and 'put' or place the components over the locations where they will be mounted. Sometimes it is helpful to use a piece of Styrofoam to do this (careful of static sensitive parts). You are looking for parts which physically interfere or connection locations or control locations which don't make sense.