SMD on single sided board with Through Hole components?

On 5/06/2017 3:11 p.m., Augusto Garcia Cinselli wrote:

Hello. I'm new here as well as a new Eagle user.

Going straight to the point, I'm just a hobbyist. I transfer muy pcbs using transfer paper.

 

The thing is that I now need to use some SMD components on a pcb I'm making that also has through hole components. What I usually do is print the PCB unmirrored and transfer it to the PCB. That way, I can mount the components from the back. That is, solder from the bottom of the PCB. However you want to look at it.

Now that I have SMDs, I need the SMD pad, and only that, to be mirrored at the time of printing so that, when I transfer, it only this is left unmirrored.

But when I mirror a component, Eagle sends it to the bottom layer. And there is nothing I can do (that I know of) to bring it back to the top layer in this state. The only way is to unmirror it.

So basically, Eagle is forcing me to do a two layer PCB when a single layer is more than enough.

 

I hope I was clear enough... if not please ask,

Thank you!

 

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Hi

Your description is less than clear so maybe the following will help.

Eagle is always a view from the top through the board.

Conventionally, if you were to design a one layer board with through

hole components you would place the components on the top side and

solder on the bottom layer. All your tracks (routing) are on the bottom

layer and hence any SMD will need to be there as well.

So for an SMD on the bottom layer, you need to mirror them. This has the

effect of making then present correctly (pin wise) as you view the board

from the top.

Then you print the lower layer mirrored so its correct for toner transfer.

HTH

Warren

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On 5/06/2017 3:45 p.m., warrenbrayshaw wrote:

 

..........Then you print the lower layer mirrored so its correct for toner transfer.

 

HTH

Warren

Woops -  mistake!

No need to mirror the print for the toner transfer

You would mirror it if producing a component placement diagram for the

bottom view.

HTH

Warren

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Thank you Warren. Sorry for the (big) delay. As I said this is my hobby and so I don't have as much time as I'd like for it ...

I understand what you propose. I should mirror the SMDs (they would then be on the bottom layer) and route. Then print the top layer and bottom layer stacked and transfer them to a single-layer PCB.

However, I'd have to make sure no routes intersect between layers...

Here's an attachment that I made to help explain myself. I know I'm perhaps not being clear...

I want to have all the components on one side and route them on that side (perhaps this is not possible).

Thank you for your help!

Attachments:

Expl.pdf

...Here's an attachment that I made to help explain myself. I know I'm

perhaps not being clear...

I want to have all the components on one side and route them on that side

(perhaps this is not possible)...

I think you have made an error in your diagram saying this is what you want

and yet in your writing you say "I want to have all the components on one

side and route them on that side". The diagram does not show that

combination.

So for toner transfer, if you want all the components, both through hole

and smd mounted on the top then you design the board with the through hole,

SMD and routing on the top layer with no components mirrored and then print

mirrored. You will need to ensure all through hole components can be

soldered from the top.

If you want all through hole components mounted on the top and soldered to

the traces on the bottom and any SMD mounted on the bottom, as they must be

when all the traces are on the bottom then. Route on the bottom layer and

mirror SMD components to the bottom. Print without mirroring for toner

transfer.

HTH

Warren

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EAGLE support forums at http://www.eaglecentral.ca :: Where the EAGLE community meets.

...Here's an attachment that I made to help explain myself. I know I'm

perhaps not being clear...

I want to have all the components on one side and route them on that side

(perhaps this is not possible)...

Yes I made a mistake there. What I need is really what I drew in the attachment.

And here's the answer:

If you want all through hole components mounted on the top and soldered to

the traces on the bottom and any SMD mounted on the bottom, as they must be

when all the traces are on the bottom then. Route on the bottom layer and

mirror SMD components to the bottom. Print without mirroring for toner

transfer.

Thank you!