place components on bottom layer without mirroring?

I thought it best to accompany my ramblings with a screenshot. lol

So in my mind, the zif sockets are on the top layer (although would be soldered on the bottom layer)

the 3  DIL IC sockets are offset to the right of each zif socket. those sockets should be on the bottom layer, but soldered on the top layer.

The switches should all be sat on the top layer and soldered on the bottom.

Brad Holland wrote:

Hey guys,

I'm sorry for being a noob but every word on the subject I find suggests

using the mirror tool.

 

I've created my pcb layout which has zif eprom sockets on the top layer

and a DIL28 IC socket which should be underneath the zif socket

(slightly offset a little)

So in essence the components are kinda stacked.

yes and no 8-)

If you dont mirror the the bottom parts, the pin assignment on them

will be mirrored regarding the IC you put into the socket.

That is you would need to bend the IC pins to top by 180° to connect

them correctly 8-)

I can't imagine that is wat you want.

if I choose mirror it flips the IC socket around which just doesnt seem

right to me.

well, see above

also after trying to mirror the ic socket i would have expected to see

the solder pads for it to be on the top but teh solder pads for the zif

socket on the bottom.

I assume you have a one layer setup? In that case you will have Pads

only on one side of the board (usualy the bottom side, layer 16 that

is).

am I being a total idiot?

no comment (sorry, couldn't resist)

--

Lorenz

On 02/20/2014 09:17 PM, Brad Holland wrote:

I thought it best to accompany my ramblings with a screenshot. lol

 

So in my mind, the zif sockets are on the top layer (although would be

soldered on the bottom layer)

the 3  DIL IC sockets are offset to the right of each zif socket. those

sockets should be on the bottom layer, but soldered on the top layer.

The switches should all be sat on the top layer and soldered on the

bottom.

Brad,

Forget about on which side the pins are soldered.  The pads are on both

the top and bottom layers since the holes are plated through.  Thus,

when you mirror one of the parts, the only thing that appears to change

is where the clamp arm is located.

To make it a bit more clear as to what's happening with the mirror, go

to Options->Set->Misc and make sure the checkbox labeled "Display pad

names" is turned on.  When the board is viewed, each pad will have the

pin number in it.  If you also turn off the Drills, Holes, tStop, and

bStop layers, it will remove some of the clutter on your board.

When deciding whether to mirror a part or not, one should consider from

which side will the part be installed?  If the ZIF is installed on the

top of the board, it should NOT be mirrored.  If it is installed on the

bottom side of the board, it MUST be mirrored.

The easiest example I can think of is to take one of your ZIF sockets

and set it on the table pins down (top installation).  Note the location

of pin 1.  Now flip it over horizontally so that the pins are up (bottom

installation).  Note the location of pin 1.  This is how it's displayed

in Eagle - viewed from the top down looking through the board.

All in all, it looks like you want the ZIF's installed on the top side

(not mirrored), and the DIL's installed on the bottom side (mirrored).

In the image, U15 is properly mirrored, while U11 and U16 are not.

HTH,

    - Chuck

thanks guys I'm starting to get my head around it a bit more after your replies.

Lorenz, to what you said about bending up chip legs, I'm not actually putting a chip into the underside ic socket, I have made some flat ribbon cables. so that shouldnt be an issue..?

So just to be sure, mirroring a part doesnt actually make it place pads on top or bottom, wherever drilled pads are there will be conductors on both sides of the board, and as you said, they are plated through (via's?)

Just in case you were wondering, I created a prototype of a hacked drum machine, and a fair few people want one, thing is, this one took me an absolute age to make due to an absolute mountain of wiring as everything is connected by hand soldering.

I'm trying to get this board made so that I can speed up the making process...

On Fri, 21 Feb 2014 15:05:49 GMT, Brad Holland

<noreply-223697@element14.com> wrote:

So just to be sure, mirroring a part doesnt actually make it place pads

on top or bottom

Actually, it does. A through-hole part has pads on both sides anyway,

so the point is moot. But if you mirror a surface mount part, the pads

WILL be moved to the other side.

What you must remember is that when you look at the bottom layer, you

see it as viewed from the top. In other words, you will look at the

underside if the parts that are placed on the bottom layer.

This might sound a bit tricky at first, but it's actually easier done

than said.

--

RoRo

I think i get you.

You mean you have to look at it imagining you have x-ray specs on, right? lol

Am 22.02.2014 15:00, schrieb Brad Holland:

I think i get you.

You mean you have to look at it imagining you have x-ray specs on,

right? lol

 

--

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Yep

--

Mit freundlichen Grüßen / With best regards

Joern Paschedag