How to move soldering pads to top layer in Eagle?

Forum 2005-2010 (read only) Hardware Development
1

Hello,

this is a very basic question and I am sure it has been answered already, but I just can't find it.

I am trying to make a PCB with electronic parts on one side (top) and pin headers on the other (bottom), like on an Arduino shield. How do I tell Eagle to put the soldering pads in the top layer?

Using the "mirror" command puts the pin headers on the bottom side of the board, creates vias and everything, but the soldering pads stay in the bottom layer. How do I move them to the top?

thank you

2

I now understand that there is only one layer for soldering pads and that the size of the pads in different layers can be set in DRC.

So the question now is - how do I set the pad size in a certain layer individually for a specific part?

3

how do I set the pad size in a certain layer individually for a specific part?

You can't. I'm not sure that you should want to, but it apparently is a feature found in some other CAD packages. If you want larger than normal "pads" in a layer, you can (at least theoretically) write a ULP that draws polygons around each pin. For example, see pinpoly.ulp in http://tech.groups.yahoo.com/group/eaglecad/files/scr%26ulp/

4

I'm not sure that you should want to

I just thought that it didn't make sense to have the pads on both sides...

Thanks for the answer.

5

I just thought that it didn't make sense to have the pads on both sides...

Take a look at any professionally mad PCB and you'll see that the pads ARE on both sides. This adds quite a bit of structural integrity (there will usually be solder on both sides too), as well as permitting signals to be routed to either side of a pin.

6

So I am curious about this too
just to be clear,
if I use eagle to create a board, then have this board printed by a company, the pads will always be on both sides?

7

the pads will always be on both sides?

There are two types of component mounting for PCBs.
There are surface-mount components whose leads attach to "SMDs" (in EAGLE-speak) or "Surface Mount Pads." These to not include any holes, and exist on only one side of the PCB.
And then there are "through-hole components" which have a ring on both sides of the PCB (actually, on ALL layers of the PCB) with a Hole in between them that the Component lead goes Through. The pads for these (almost) always appear on both layers.

The common exception is single-sided boards, which are implemented by only giving the PCB fab house one layer to print; in the CAD files the pads are still on both sides, but only one side is actually fabricated.

8

OK thanks for the clarification.