Tuesday, March 12, 2013

Larger Boards in EagleCad Free

A few years ago I made a large flexible LED sign on some copper clad kapton. I used the toner transfer method to etch the kapton but I quickly ran into the dilemma of board size. I was using the free version of eagle cad and was limited to 100mm x 80mm. My boards were in the range of 160mm x 120mm. After a little trial and error I found a way to bypass the board size limitation without modifying eagle cad in some illegal way.

First let me say this works best for a simple repetitive design. I needed it for the 1 layer surface mount display boards which used a simple layout repeated multiple times.

Starting in the board layout window draw a component. For me it is the large LED. I used the rectangle tool to draw the pads in the TOP layer and the line tool to draw the chip indications in the TPLACE layer.

Figure 1

Next I copied it around to form my 4 LED pixel.

Figure 2

This part is a little tricky. I laid down the traces without any nets for guidance. Use the line tool to mark where you want the copper to stay.

Figure 3

Repeat until the pixel block is complete. Copy pixel block to form half column block. Add connection pads to bottom and connect pixels.

Figure 4 : Rotated Left for better fit

Copy this around to form full display.

Figure 5

Success! Eagle cad will gladly let you make this board and export to PDF or gerber. Side note, each line you draw counts as a new net so DRC will still work.

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