Plane ground bottom pads

Hi,

You question is not very clear to me! Do you mean that you've placed a

Polygon on the bottom layer of your circuit board, and used the 'Name'

function to define this polygon as GND? Also, are you talking about

thru-hole components or SMT components?

This may be a case were we actually need to see what you are talking about

to help!

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

Hi

Yes it's exactely what i did. It concened all the components. I only use SMD components. The area around the pads is not in ground

Hi,

I still don't have a completely clear picture of your situation. Are these

SMT components on the Top layer or the Bottom layer? If on the Top, I would

generally expect the GND fill under the SMT components on the Top layer. If

on the Bottom, I would expect the GND fill to be around the non-GND pads

with a suitable clearance 'relief', and for GND pads I would expect that

they would be connected to the GND plane. The only exception I can think

of, where GND connections would still be connected with 'air wires', would

be if somehow the GND polygon was not continuous. You'd only see this for

components on the Bottom layer.

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

Hi,

My components are on the top layer. I will send you a picture it will be more clear maybe. On the picture you can see that i have areas where there is no plane ground. Theses areas are where i have my pads but in the top layer.

On the bottom layer, i have few routes and the ground. Do you understand more ?

Thank you in adance.

I have two planes ground (bottom and top layer).

Thank you.

Hi,

Where did the SMT part definition come from? Did you find it in a specific

library, or did you create it? If you found it in a library, which one, and

what is the part name?

The only thing I can think of is that you have some sort of a 'Keepout' or

'Restriction' on the bottom layer (bKeepout or BRestriction layers) defined

for the part(s). I've never used it, but ordinarily I believe this is to

prevent copper from being placed underneath certain components (crystals,

etc.) for impedance control purposes. Can you look at the layer definition

for the part(s) that are the problem?

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

Hi,

Where did the SMT part definition come from? Did you find it in a specific

library, or did you create it? If you found it in a library, which one, and

what is the part name?

The only thing I can think of is that you have some sort of a 'Keepout' or

'Restriction' on the bottom layer (bKeepout or BRestriction layers) defined

for the part(s). I've never used it, but ordinarily I believe this is to

prevent copper from being placed underneath certain components (crystals,

etc.) for impedance control purposes. Can you look at the layer definition

for the part(s) that are the problem?

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

I created my own library. How can i check the definition of a layer ?

Hi,

If you created your parts from scratch then it's probably not the issue,

but if you started with an existing part then it might be. Look at the

'Package' view in the library, and see if anything, typically a

cross-hatched box, surrounds your pads. Use the 'Info' tool to check the

layer definition for everything on/around the pads.

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

I try to see if it's the name with a library of Eagle and i have the same results. I use library 40 xx with a DIL8.

Thank you.

I think my problem is because i put my components like SMT in the "reality" but with the software understand that i put them like through hole. I think i have to change the pads of my own library in SMT pads ? But how can i have the same forms of pads ? I have no choice in Eagle ?

Thank you.

Hi,

Try this tutorial:

https://learn.sparkfun.com/tutorials/designing-pcbs-smd-footprints

Good Luck!

John

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.