Protoboard/Veroboard alternative for huge LED sign?

Question

I'm preparing for a project which is an LED sign, it will be an LED matrix, but only have the necessary LEDs attached so it will only display one "word" but each individual LED of the WORD can be controlled for nice patterns etc.

In the image below tracks run horizontally. As can be seen, a single LED obscures 3 holes in its width, and one space must be left above each LED.

Ignore tracks in the image above, it's merely to show spacing and not electronic contact.

Now I have received my LEDs and measured properly, the real dimensions I require are as follows: 114 LEDs wide, 28 LEDs high

342 Holes wide (min) 
84 Strips high (min)
80cm wide (approximately calculated minimum) 
23cm high (approximately calculated minimum)

The board doesn't have to be copper type vero/proto/matrix, it can be plain, but I need something that will rigidly hold the LEDs evenly spread so I can wire them up how I need off the board if necessary. It doesn't have to be one piece, but I do want to achieve even spacing, cost is an important factor in the choice.

Answer 1

This is pretty close at 58cm wide, although only 10cm tall.

However, assuming board(s) will be mounted on something, why not use two (or more) pieces of veroboard? You could bolt/epoxy/solder some together.

Most PCB manufacturers can make you a board this size if that is an option.

The 60cm sounds about right for 2.54mm pitch, but how do you calculate 360 holes needed for 114 LEDs? (are they 3 leads?)

Things like a rough diagram of your intended setup, type of LEDs used, picture of VeeCAD layout might be helpful to find the best solution.

Answer 2

You really want to get a PC board made for this sort of thing. Veroboard can be useful for quick prototyping of small circuits, but it's just not appropriate for this.

I didn't look at your picture since it was way too big to see in the browser window (does it really need 8 Mpixels to show!!?), but I see some issues with your much smaller (and therefore viewable) layout diagram.

First, you are connecting at least two of the LEDs in parallel. This is a bad way to drive multiple LEDs even if you always want them lit together. LEDs do not share current well when driven with the same voltage. Use separate load resistors or connect them in series if you want them driven together. However, you also said you want each LED driven seperately, which putting two in parallel certainly doesn't do.

Second, you seem to be using thru hole LEDs. It's going to be expensive getting all those mounted. Surface mount LEDs are smaller so can be packed tighter or leave more room around them for connections. But most importantly they can be automatically placed on the board, saving a great deal of assembly cost.