How to panelize circular PCBs

[beckmx]

Hello guys I noticed for the panelizer ULP there seems to be an issue when i just use a circle as outline for the board, lines are working no problem, but full closed circles seem that are not able to be panelized.

Thanx for the amazing work :)

[PaulZC]

Hi,

The panelizer calculates the size of the PCB by looking for dimension lines with the greatest and least X and Y coordinates. A circle is defined by center and radius, so I'm guessing the panelizer won't be able to find the 'edges'.

If you want truly circular PCBs, you'll need to order them individually. Paste stenciling and pick-and-place then become a bit of a nightmare...

Or, you could add small flats or tabs top, bottom, left and right. The panelizer should be able to detect and use those as the dimensions. The v-scores should then end up in the right place. Size the tabs carefully and you would only have a little material to sand off after reflowing and separating the complete panel.

Here's an example.

Thanks for the feedback!
Paul

[PaulZC]

Just for giggles, and only because it is Sunday:

Let's say we want a 1" diameter PCB.
The default v-score groove width we use for JLCPCB is 0.02". So I'm going to take 0.01" off top, bottom, left and right. When the PCBs are snapped, they should be exactly 1" diameter with only a tiny bit of sanding to do.
To remove 0.01", the flats need to be almost exactly 0.2" wide. Handy!

Delete the circle. Add the flats. Join the end points with an arc. Play about with the arc "curve" until the radius is close to 0.5". (Or calculate it properly....)

Copy, rotate and paste the remaining arcs:

The moment of truth... Will it panelize?

Ta da!

[PaulZC]

One final bit of advice:

We always add the text "Route Out" on the dimension layer on any spaces like this. It just makes it clear for JLCPCB what is PCB and what needs routing / milling.

[beckmx]

Thanx! I was doing that but I just felt like I was not in the right path, thanx for confirming

[lewispg228]

Hey Beckmx and Paul,
All good stuff. I like your approach listed above. Just as another though and option, I wanted to share how I panelized a recent revision to a lilypad design.

I fooled the panelizer tool by adding in some "L" brackets to each corner on the dimension layer. This way the panelizer can pick up on the outer edges of the curved PCB outline. After the panelizer was complete, I did have to go into the panel file and delete my "L"s, which took quite a few clicks, but it worked. I also thought about leaving them in there; I'm guessing most fab houses would just ignore. But they also might get confused, and that could delay your order.

Also, depending on the design, sometimes it's nice to add some extra tabs in between each board to add a little extra strength to the panel. It's more of an issue with thinner PCBs, but thought I'd mention it.

Cheers!
-Pete

[PaulZC]

Nice! +1 for fooling the panelizer!

[edspark]

Clever solution that really shows the panelizer who has the bigger brain. =P