PCBs are panelized when you need or want to run more than one board through a pick and place machine at the same time. Read more about the “whys” here. And while you’re getting familiar with the background for this post, you can also read more about this particular design in our old blog archive, here.
V-score can only panelize in straight lines
Now take a look at the board our partner, Sunstone Circuits built for the YDY project. It’s not a large board at 1.3″ x 1.6″ x 0.042″ thick. We built a run of 400 and didn’t have much time to get it built.
Panelizing allowed for much faster assembly, which Sunstone did for us. They started with V-score to allow for a quicker depanelization time. I wanted rounded corners for the design and a cut out for the tiny on off switch. V-score can only panelize in straight lines.
We asked Sunstone to use v-scored along the straight edges and then route it for the rounded edges and cut out. It’s not a normal thing, so if you need two types of panelization like we did, be sure to call it out clearly in your fab drawings or a call or email to customer service.
A couple of other important things to note here:
See the fiducial on the panel upper left corner and see the fiducial on the individual PCB? Both really good ideas.
There is a second fiducial on the panel that you can’t see due to my image trimming. The two fiducials on each board are in an asymmetrical pattern such that our machines can only orient the panel in the correct way. You can get a little more detail on fiducials here.
Also, the smaller QFN closest to the Screaming Circuits logo (see the top image), for the accelerometer, has a via in the center area. That part does not have a metal pad in the center as many QFNs do. If the part did have a metal pad, I would not have an open via in there.
Duane Benson