Today's trick is: using jumper wires when single sided routing won't work
For the home DIYer, single-sided PCB fabrication is well within reach. Double-sided, not so much. I find it easiest to hand route most of my designs to ensure the traces are exactly where I want them.
Occasionally, there is just no easy way to route every trace on the bottom. Using jumper wires on the top side of the board is a simple way to complete the single-sided design.
Walk Through Example
In upgrading Pokey my firefighting robot, I created a board to interface a Solarbotics Ardweeny (ATMega328P with a backpack board) to a GameBoy camera to detect flames.
I'd laid out the entire board but pin 12 and pin 26 on the ATMega328P still needed to be connected (see pink arrows below). There was no convenient way to do this on the bottom layer. Notice pin 12 has a trace going up to pin 8 of the top pin header, which is the camera interface.
Please ignore the vertical red trace on the left of the board. Its purpose will be discussed in another article.
|How to connect pin 12 and 26? With a jumper...|
|Draw trace. Ensure there's a horizontal section.|
Once you've drawn the trace and connected the pins, right click the horizontal section of the trace, and select Properties from the contextual menu.
|Right click the trace and select Properties|
|Select Top from the Layer menu to move the trace.|
|Implement the top layer traces as jumper wires.|
You can increase the size of the vias to something more normal like 0.039" or 0.031" diameter holes by right clicking each via, and choosing Properties from the contextual menu.
|Select Properties for each via|
|Select the via's drill size from the pull down menu.|
Here are a couple more examples of my use of jumper wires on boards I've designed.
|Serial board with jumper for handshaking|
|Vertical jumper between V+ input and 555 timer IC's Vcc pin.|