power plane problem : pad overlapping with ground pour

[legolaself]

Hi,

This is my first PCB layout design. I have attached two images : with/out powerplane.

To create power plane i have selected the ground net as copper bottom. But after i do that

some pad seems to be overlapping with ground pour. Please tell me how solve this issue.

Thanks

[stressed_user]

Hi,

try this:

In your power plane settings, increase the clearance, it looks rather small.

After adding a ground poor, do a DRC check, this updates your design and checks all distances...

succes

Stressed user

[legolaself]

Hi,

i have increased the clearence. But now they overlap each other.

Do you think that could be a problem??

Is there a way to make the antipad square rather than circular ? that would solve the problem without increasing clearence i guess.....

[stressed_user]

Hi,

I think I might have found you problem:

Your power plane is probably on the bottom, is it?

And the pins pad could be as follows:

-it has a square pad on top, and a round pad on the bottom.

when you pour a powerplane around it, on the screen, it looks like it is overlapping, but it isn't.

I made a screenshot of my test:

the green area (copper pour on the top side) goes nicely around the square pad

the red area (copper pour on the bottom)  seems to make a short circuit.

It doesn't because the pad on the bottom is round...

I hope this solves your problem

stressed user

[legolaself]

yes you are right....

I am using Bottom as an Ground plane....

And yeah, the bottom of the pad is round but i wonder how did you know. is there a way to know this??

I knew only after seeing gerber files so could not be sure whether they are in short circuit condition.

Also i did not use the Top as power plan.

How important is to do that...

Also if I want to use it as power plane, should i select the +Ve or -Ve net 

Sorry for so many questions...

Thanks

[stressed_user]

How did I know? 🙂 experience I guess

If you switch off the top layer completely, you could also have seen it...

then the pad shape would have been circular, being the bottom one.

For a simple board, a bottom ground layer is usually sufficient.

I would suggest you do use larger tracks for your other signals.

go to .25  or .5 mm (or if you live in the US: 100 or 200 mills.)

Succes!

[legolaself]

sorry, did not get you there.....

you mean 10 or 20 mils right?? (100 mils too big!!!)

in the picture, i am using .5 mm for power tracks and .25 mm

for other signals. so may be it is better to make all the tracks

.5 mm.

[stressed_user]

Yes indeed,

10 to 20 mills, I'm used to work in mm's...

Using .25 and .5 is ok

But since you have enough space, you can enlarge the power tracks to 1 mm...

Sorry for the confusion 

stressed user