Panelization tips for metal core PCBs - Page 1
Forum section: electronics / general

author: dkonigs
author_rank: Regular Contributor
timestamp: May 23, 2025, 04:16:24 pm
content: There is a lot of info out there on general practices for panelizing PCB designs, but its almost entirely focused on your standard FR4 PCBs.I'm working on a relatively small PCB that's going to be produced withJLCPCB's copper core process, and need to come up with a decent panel layout.My current layout looks something like this:Its a pretty straightforward v-scoring approach, with wide tabs on the edges to make the rail-to-rail dimensions nice round numbers.Does this look like a decent layout? Should I be doing something else to separate the boards a bit more in the panel?I'm wondering how well this will work, and how hard it'll be to pop apart the boards after assembly.Its hard to know what I should be doing here, because (as mentioned above), none of the panelization advice I've seen spends any time talking about whether metal core PCBs bring in different considerations.In case you were curious, I decided to see what JLCPCB's own panelization features did on their order page. They don't seem to do anything different depending on the PCB type. Of course without actually placing an order, I have no idea if they'll deviate once engineers actually prepare the design for manufacture.Thanks.

author: incf
author_rank: Frequent Contributor
timestamp: May 23, 2025, 07:09:56 pm
content: I have no direct experience, take with a grain of salt.I'd be worried about flexion.But I don't know how stiff or flexible a copper PCB is (especially after v-scoring)When in doubt, ask the manufacturer.

author: thm_w
author_rank: Super Contributor
timestamp: May 23, 2025, 09:27:51 pm
content: Previous thread:https://www.eevblog.com/forum/manufacture/jlcpcb-copper-core-pcb-differences/So you are assembling them yourself or JLC is doing it? If JLC does it then they can figure it out.Only thing I see with your design is the inner beveled edges won't come out like that, because the router bit is ~2mm and can't make a tight square corner.

author: dkonigs
author_rank: Regular Contributor
timestamp: May 24, 2025, 02:26:59 am
content: Quote from: thm_w on May 23, 2025, 09:27:51 pmI'm having a 3rd party assemble them, but I'm probably de-panelizing them myself. Its okay if the inner beveled edges aren't perfect, but keeping those cleaner might be one reason to add tabs/gaps between the boards. I guess what I'm really looking for here are some good practical examples of how to handle this, given that I don't expect metal core PCBs to just "pop apart" as easily as FR4 given a similar v-score.

author: incf
author_rank: Frequent Contributor
timestamp: May 24, 2025, 02:41:36 am
content: I'd wonder if the components might get damaged from trying to separate the boards out by hand. (not sure about the stiffness or depth of scoring)no access to a depanelizer machine? I guess you could screw a section of it down to a fixture. Or make specially shaped soft jaws for a vise.tab and slot is probably friendlier to deal with by hand if you don't mind the rough edges.I've wanted to make use of these sorts of copper core PCBs for a while now, but always have been put off by the cost. It'll be interesting to see how it works out.

author: dkonigs
author_rank: Regular Contributor
timestamp: May 24, 2025, 04:59:56 pm
content: So I've been plugging at it a bit more, and decided to try out the following changes:I basically added tabs between the boards, and reduced the total width to make things more manageable.Of course I'm still not entirely sure what tab widths to use (and whether to go the full width of the flat section on the top/bottom of the boards, or something smaller like in this picture), as well as other minor details of all this.That's why I'd really like to see some actual examples of this, which I'm really struggling to find anything decent out there.As far as actually doing the board separation, if some force ends up being required then I'll make my own jig(s) to help with the process. There are a lot of flat areas where I can safely press/clamp on these boards, so doing something to aid manual separation shouldn't be too bad.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: May 25, 2025, 01:45:57 am
content: This is much better but your board is 15cm in length. So, maybe 2 tabs will be more supportive.

author: dkonigs
author_rank: Regular Contributor
timestamp: May 25, 2025, 03:05:08 am
content: Quote from: 48X24X48X on May 25, 2025, 01:45:57 amI think the way the V-Cut lines cross the dimension lines was confusing. Its the entire panel that is 135mm x 150mm.The individual boards are only 20mm x 43mm.(and right now those tabs are 5mm wide)

author: mtwieg
author_rank: Frequent Contributor
timestamp: May 26, 2025, 01:54:10 pm
content: Are there any IPC standards (like IPC-2221B) for metal core PCBs? Google doesn't turn up any...This is definitely something you should consult with the fab and CM about. I've never dealt with copper-core PCBs, but I presume they have very different quirks from aluminum due to pure copper's high ductility (AFAIK pure copper is used for MCPCBs). Once the array is routed and scored, bowing could become an enormous problem.

author: kate
author_rank: Newbie
timestamp: June 02, 2025, 08:30:49 am
content: I am a  from China. The manufacturers here that produce copper-based PCBAs all use this kind of equipment for cutting. It will save you a lot of unnecessary trouble and can avoid the stress issues caused by panel separation.

author: Doctorandus_P
author_rank: Super Contributor
timestamp: June 03, 2025, 02:42:47 pm
content: I don't know if V-cuts work with IMS. If it does, then your first version should work just fine, except for the chamfered corners which form a square.For routing. There is a minimum width of the thickness of the router bit. Generally between 2 or 3mm or there abouts. And your PCB manufacturer is the only one who knows which router bits they use. Some have guidelines about preferred widths on their website.

author: Accu-Sembly
author_rank: Contributor
timestamp: June 04, 2025, 06:10:47 pm
content: We work with aluminum PCBs quite often and your second panelization should work fine. Personally, i would do rails and 2 rows instead of 3. It's much easier for the equipment to support a rectangle where the supported sides (rails) are longer than the floating sides (no rails).As far as removing them, as long as they are scored properly, you will be fine. They won't "pop" like FR4, they're more pliable, so you might have to bend the tabs back and forth a few times. For that reason, your first panelization would be pretty challenging on the long side of the individual pcbs.

author: dkonigs
author_rank: Regular Contributor
timestamp: June 05, 2025, 12:14:40 am
content: Just to chime in again here...This thread went for so long without further replies that I already went ahead and ordered the panels last week. I went with the second design. Hopefully it'll work out okay.While I get some of the follow-on advice as far as the rails, these aren't that big or complex so hopefully it should still work out.I might also end up making some 3D printed jigs to help me safely hold the boards by unpopulated areas while separating them, and have also been going back-and-forth on the idea of spraying the back/sides with some sort of basic conformal coat material. (The residual fab coating on the boards might be enough on the back, but maybe not on the sides.)

author: Accu-Sembly
author_rank: Contributor
timestamp: June 05, 2025, 12:42:22 am
content: You're panelization as ordered will work. The metal core provides much more structural support than a normal board.... and you're probably over thinking it. Once you receive the PCBs you might find that you can just work it with some plastic pliers and be fine.

author: Accu-Sembly
author_rank: Contributor
timestamp: June 05, 2025, 12:55:28 am
content: I just realized that you asked for examples. Here is an example of one metal core layout we process. On the green one, the contact lines are v scored, 9mm long on the bottom and 7.5mm long on the top. The red layout is the same PCB but was not a desirable layout. It tended to sag during reflow even with an aluminum core, and the long contact lines, although scored, were much more difficult to separate.