Push to fusion - (DRC) Incorrect board thickness

[ezekiel.brooks89]

Hi all,

Anybody else experiencing an incorrect board thickness when pushing to fusion 360?

I push a board with a DRC of 0.8mm and in fusion it measures 0.772?

[jorge_garcia]

Hello @ezekiel.brooks89,

I hope you're doing well. If the dimensional thickness accuracy is important for your board make sure to include the the stop mask when you put to the 3D PCB. Stop mask (the stuff that makes PCBs green and avoids you shorting pads everywhere) has a small thickness and that likely explains the discrepancy you are seeing.

Best Regards,

[ezekiel.brooks89]

Hi, thanks for responding however this has not solved the issue.

This is a relatively new issue as my previous versions of eagle/fusion 360 imported the board thickness as per the DRC "0.8mm".

All of my designs have stopmask, but I still get random board thickness between boards.

I remember fusion/eagle had this issue before, and it was solved with an update, but now its seemingly back again..

The feature is massively important to my design, as I am building a case with mm precision around the PCB in fusion360. With the board thickness incorrect, this throws out all of my component 3d modules that are linked in my managed library.io.

[jorge_garcia]

Hi @ezekiel.brooks89,

I hope you're doing well. Recently we changed the push to 3D PCB so that the Stopmask is not automatically generated(it's one of the most time consuming features to generate). So I would still recommend that you double check and make sure you are checking the Stop Mask checkbox before you push to 3D PCB.

@yqliu could you confirm any other reason why the thickness would be different?

Let me know if there's anything else I can do for you.

Best Regards,

[ezekiel.brooks89]

Hi @jorge_garcia,

Perhaps I'm missing something? You mentioned checking the tick box for including the stop mask, however I cant see this option anywhere and haven't used that previously.

See attached screenshot. Where should I look for this option?

Many Thanks

[yqliu]

@ezekiel.brooks89 , the option that @jorge_garcia mentioned is in Fusion electronics environment. We have a more powerful 3D PCB generation command inside Fusion. 

Is the board you are using a single layer board? I remember there is a bug for single layer board.

[C.Nicks]

The issue is that Fusion does not count the external copper layers thicknesses.
In my case I set the plating to 0 and set the core stack to equal the thickness I'm targeting.