Placing single-sided pad onto a two-sided PCB

On 08/05/15 01:51, Tom Keevers wrote:

Hi everyone,

 

I would like to make a two-layer PCB with a via at the top which is

connected by a wire to a single-sided pad near the bottom.

 

Why? What is the function of this PCB? Is it really a "VIA" that you

want? Or is it actually a PTH pad?

All these questions must be answered first. If you haven't answered them

then you are not using Eagle as a PCB design tool like it's intended to

be, but rather you're faffing around pretending it's a very expensive

version of MSPaint.

My minimal working example is to create a new board,

Probably the wrong first step. Even for something as trivial as this,

you're better off starting with a "this is what I'm achieving" plan

(a.k.a. schematic).

followed by

GRID MM 0.1; % Change units to mm

 

% Create board outline

LAYER 20 ;

WIRE 0.25 (-3.5 0) (3.5 0) ;

WIRE 0.25 (3.5 0) (3.5 15) ;

WIRE 0.25 (3.5 15) (-3.5 15) ;

WIRE 0.25 (-3.5 15) (-3.5 0) ;

 

% Create via

LAYER 17;

Circle 0.1 (0 13.5) (0 13.8) ;

WRONG! You don't draw a circle on the via layer to create a via (even if

a via really is what you want). You use the "VIA" command to create a via.

   CHANGE DRILL 0.5;

   VIA 'N$1' 0.7 round (0 13.5);

See "help via".

 

% Create wire

LAYER 16;

WIRE 0.3 (0 13.5) (0 10) ;

Again, you shouldn't really use the "wire" tool for tracks, although it

will work. Better to place the pad first, using the same net name as the

via, then route them.

Much better still, create a schematic first. On this, place two

components: a through-hole test pad and a surface mount test pad. Then

place a NET between them. You now have your intent declared. Create a

board from the schematic. Move the two pads to where you want them. You

will see an "air wire" between them. ROUTE that air-wire. Job done.

Hey,

Thanks for the detailed response.

The overall aim of the board is to connect an LED which is held between two PCBs (only one of which is used for connection) and an external power source.

The original design I had in mind was to connect a wire to the via, use a track to connect to a pad and then connect the pad to a fuzz button through to the LED.

Using a schematic seems like a better approach. Just to check, I want to use the “2,54/0,8” (or similar) pad and the “SMD2” pad under the wirepad category?

On 12/05/15 07:57, turkey wrote:

Hey,

 

Thanks for the detailed response.

You're welcome.

 

The overall aim of the board is to connect an LED which is held between

two PCBs (only one of which is used for connection) and an external

power source.

 

The original design I had in mind was to connect a wire to the via, use

a track to connect to a pad and then connect the pad to a fuzz button

through to the LED.

 

Using a schematic seems like a better approach. Just to check, I want to

use the “2,54/0,8” (or similar) pad and the “SMD2” pad under the wirepad

category?

 

Assuming those are the sizes that work, yes, they're the components to use.

On 12/05/15 07:57, turkey wrote:

Hey,

 

Thanks for the detailed response.

You're welcome.

 

The overall aim of the board is to connect an LED which is held between

two PCBs (only one of which is used for connection) and an external

power source.

 

The original design I had in mind was to connect a wire to the via, use

a track to connect to a pad and then connect the pad to a fuzz button

through to the LED.

 

Using a schematic seems like a better approach. Just to check, I want to

use the “2,54/0,8” (or similar) pad and the “SMD2” pad under the wirepad

category?

 

Assuming those are the sizes that work, yes, they're the components to use.