A Question For Those Who Are Familiar With Cadsoft EAGLE And Board Houses

idbruce

Hello Everyone

As many of you already know, it is not easy to create a perfect polygon for your copper pours, so I have a question pertaining to EAGLE generated files and board houses. For the sake of discussion, let's assume that I am working on a ground plane and that it would be very difficult to complete it with a single polygon fill, which does not include covering the whole board with a single polygon. Is it acceptable to the board houses to do a series of polygons in various stages. In other words, if several polygons are used to make a single copper pour and therefore overlap one another, providing they all have the same NAME, would this be a problem for the board houses?

Thanks in advance.

Bruce

Beau Schwabe

To my knowledge most board houses use Photo developing, so anything on a layer gets flattened anyway. Unless the board house uses rastering to mill the PCB out rather than etch the PCB, I wouldn't think there would be a problem. Even then it would just be a question on the amount of time the machine spends on the board if the layout was not optimal.

idbruce

@Beau

I was thinking the same thing, because I can't imagine it making a difference with a photoimaging process. At the most, it should only require a little more processor time, perhaps uS(s).

Bruce

Duane Degn

Bruce,

I haven't use Eagle much but I know in DipTrace you just define the edges of a copper pour and the software fills in the area for you.

I was also under the impression that once a file was converted to gerbers, the layers were flattened and any overlapping polygons were combined.

tonyp12

In diptrace you select: Snap to board outline.
And you can select priority if you another copper pour on top of that in case it belongs to a different net.

When exported as gerber, it is flatten and area is now drawn as by a bunch of thin lines, edges are lines drawn at a angle.

idbruce

Okay guys, there is a very specific question, but I believe were all in agreement, and I also believe it is one gerber for the bottom layer, which means it is flattened. As for the basics, I believe I have that down pretty good. The attached image shows a board with (6) very distinct and seperate copper pours, so one pour just won't cut the mustard

Bruce

tonyp12

Right side, second (and also 4-5) from top shows a pour that is not connected to anything, not good.
Add a via to top gnd pour etc

Or select in pour settings to not draw islands
and move traces around to minimize blank (etched away) space.

On dip,left side
pin 2 and 11 move the traces so it enters in corner,
you now have small 270deg angle pockets for etch to stay for too long.

idbruce

tonyp12

HUH?????????? HMMMMMMM....

Everything is just the way I currently want it, although I am not finished with it just yet. There is nothing wrong with having sections of pours that are not connected to anything, in fact it is beneficial because it uses less etchant to process the board where no circuitry exists.

Bruce

idbruce

tonyp12

Sorry, I should have read your post better. I will take another look at what you said later today.

idbruce

@tonyp12

I took into consideration your words of advice, and although I may be wrong, I think it might pass. The board has changed a little from the first image shown, so I have included a more recent image of the boards current state, and I additionally have attached a PDF of the bottom layer, because it looks so much better when printed. Perhaps you might not be so skeptical with the printed version.

Bruce