Layout for double sided components PCB

[Anonymous]

How do make a layout in eagle for a double sided components PCB? 
I did a little research and found an answer but I'm not sure if it is correct.

"In Eagle, in "board view" (where you design the PCB), select the "i" tool (the tool that brings up the "properties" dialog) and click on the component you want on the other side of the board, check "mirrored" and that's it!"

Mirroring the component doesn't change the layer of the component! I wanted to ask whether it should change or not? 
All the components initially are on the top layer i.e Layer 1 and my instinct tells me that if I want to make a double sided PCB the components to be soldered on the other side should be on the bottom layer. Am I correct in saying so? If yes, then how do I do it?

[rachaelATWH4 · Accepted solution]

---

@Anonymouswrote:

How do make a layout in eagle for a double sided components PCB? 
I did a little research and found an answer but I'm not sure if it is correct.

"In Eagle, in "board view" (where you design the PCB), select the "i" tool (the tool that brings up the "properties" dialog) and click on the component you want on the other side of the board, check "mirrored" and that's it!"

Mirroring the component doesn't change the layer of the component! I wanted to ask whether it should change or not? 
All the components initially are on the top layer i.e Layer 1 and my instinct tells me that if I want to make a double sided PCB the components to be soldered on the other side should be on the bottom layer. Am I correct in saying so? If yes, then how do I do it?

---

Hello,

In EAGLE when you mirror components they change from the top layer to the bottom layer. If they are SMT parts you should see their pad colour changing but with TH parts you don't actually see this as the pads are green on both sides.

You will see that the silk screen related items which are on tPlace, tNames, tValues will change to be on bPlace, bNames and bValues.

However, the method you found is the long winded way of doing it. Just issue the mirror command and click on the parts you wish to put on the opposite side.

Best Regards,

Rachael

[Anonymous]

Thank you so much Rachael. Just the answer I needed. Thanks again.

[Anonymous]

I don't get that in Eagle 9.4.0. For the first time, because of vertical clearance problems, I need to move a connector from the top to the bottom layer. When I activate the MIRROR command all I get is a horizontal flip of the connector when I click on it. I could tell if it goes to the bottom layer because it's TH pads are vertically asymmetrical and should change vertically when it moves to the bottom layer (i.e. - it gets turned over). I've tried various key combinations like cntl, alt, before clicking the component but no help. I also tried doing it in the editor window but it remains on top. What am I doing wrong?

[one-of-the-robs]

---

@Anonymous wrote:

I don't get that in Eagle 9.4.0. For the first time, because of vertical clearance problems, I need to move a connector from the top to the bottom layer. When I activate the MIRROR command all I get is a horizontal flip of the connector when I click on it. I could tell if it goes to the bottom layer because it's TH pads are vertically asymmetrical and should change vertically when it moves to the bottom layer (i.e. - it gets turned over). I've tried various key combinations like cntl, alt, before clicking the component but no help. I also tried doing it in the editor window but it remains on top. What am I doing wrong?

---

I suspect you're misinterpreting what you're seeing. Try turning off the visibility of the top layers (tPlace, tNames, etc.) to see whether Eagle thinks your connector is still on the top.

What do you mean exactly by "its TH pads are vertically asymmetrical"?

[Anonymous]

Yeah, disabling some layer settings cleared up the issue. I'm now convinced that the component was moved to the bottom layer. One confusion factor was that the MIRROR command not only moved the connector from the top to the bottom layer but it also flipped it horizontally which I didn't expect. I've attached a screenshot of the board. The upper left connector J7 appears as it should be with the two small pins correctly shifted upwards. The upper right connector J8 remains on the top layer but has been rotated 180 degrees so the pins appear in the same position vertically. Now, the only remaining question I have is why is Design Manager still showing J7 on the Top Layer?

[one-of-the-robs]

---

@Anonymous wrote:

 One confusion factor was that the MIRROR command not only moved the connector from the top to the bottom layer but it also flipped it horizontally which I didn't expect.

---

Well it has to do something   If the component is being fitted in the bottom then you're looking at its underside, which you do by flipping it over. Either you flip it horizontally or you flip it vertically. Eagle does horizontal but you can rotate by 180 to get the same result as vertical.

---

@Anonymous wrote:
Now, the only remaining question I have is why is Design Manager still showing J7 on the Top Layer?

---

That is a good question. I don't use the Design Manager (doesn't fit my mindset) so I wouldn't have noticed such a misbehaviour. I may have a play when I get home and have access to Eagle.

[one-of-the-robs]

I've just had a bit of a play and I don't think I'm seeing what you report but...

There is one specific misbehaviour of the design manager that may be confusing. When I select the devices with the "Bottom side only" filter, and then mirror a device that's currently on the top, it does not appear in the list. However, changing the filter to "all" then back does refresh the list so that it now appears as on the bottom. If I mirror it back to the top, it does get removed from the design manager's "bottom" filtered list immediately; it's just the adding that fails.

[Anonymous]

Well, at least I wasn't completely crazy. 🙂 Thanks for taking the time to check it out. I'll play with the Design Manager to understand it's behavior.