V groove separator

[Mangozac]

Typically we have always just carefully flexed the PCBs along the v-score grooves to separate them but we have a new design with a QFN that is a bit too close to the v-score so I'm worried about damaging the joints with the flexing motion. There are plenty of v-groove separating machines on Aliexpress for under US$1k (https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20200923000046&SearchText=v+groove+separator). Does anybody had any comments on these types of machines before I go purchasing one?

Or would it be smarter to avoid v-grooves altogether and simply go with mousebites in the future? I would have to get a new stencil done but that's a much lower cost than a v-groove machine! The downside to mousebites is that I would have to panellise myself rather than taking advantage of JLC PCB automatically panelising for me.

[T3sl4co1l]

You're seriously contemplating a $1,000 machine, while being concerned about wasting a $10 stencil?!

Tons of fabs offer panelization.  Heck, I don't think I even know of a fab, that would charge more than $1000 for an order, for a board that any bargain proto service (JLC) can fab.  It's not even custom, it's just going to be standard proto stackup, right?

Tim

[Ian.M]

Specify that part of the board outline as a narrow routed slot on the V groove line?  A slot of length 3x the QFN footprint diagonal centered on the closest part of the edge to the QFN should provide effective stress relief.

[SMTech]

Specify that part of the board outline as a narrow routed slot on the V groove line?  A slot of length 3x the QFN footprint diagonal centered on the closest part of the edge to the QFN should provide effective stress relief.

One would have to assume there's another board right next to it in the panels, hence a slot meaning a new stencil as it would change the step.

It has to be said the Ali versions are quite a bit different looking to what you might get from your local supplier, this design seems much more common https://www.cab.de/en/electronics/pcb-separators/ (and is available with many badges on it). It is the way to go for V-Scored panels up to the point you have get routers to depanel your PCBs (maybe even laser ones).

[Ian.M]

One would have to assume there's another board right next to it in the panels, hence a slot meaning a new stencil as it would change the step.

Not if the other side of the board outline can tolerate a matching routed section, and is specified accordingly.

However I agree that may be impractical and it would also be undesirable to have very narrow V grooved strips of waste between the PCBs.

[ar__systems]

I have that v-groove separator, it works great. Cost is a major factor why people use v-cuts.

[Matt-Brown]

We give board houses the specs that we want the panel done to and they do it. So if you want once edge routed and tyhe other v-score you just put it on the fab text file. We have boards with SMT USB connecvtors and tell the raw board fab house to route that edge, or under the usb area. We have never had to send them a panel file.
Most times I state in the text to panel I try and keep mya rrays to a 9x6 area or less. Then add 0.3 rails all around with fids toward each corner of the breakaway.
We also try and use a depaneling machine as much as possible to avoid edge fray on assembled boards

[Mangozac]

Thanks for the comments guys. While adding correctly designed slots may work in some cases, I'd rather just avoid the risk altogether. It sounds like it's time to pick up another new machine! 

It has to be said the Ali versions are quite a bit different looking to what you might get from your local supplier, this design seems much more common https://www.cab.de/en/electronics/pcb-separators/ (and is available with many badges on it). It is the way to go for V-Scored panels up to the point you have get routers to depanel your PCBs (maybe even laser ones).

I had a look around and that style is 3-4 times the price. I can't imagine it works that much better?

[SMTech]

Thanks for the comments guys. While adding correctly designed slots may work in some cases, I'd rather just avoid the risk altogether. It sounds like it's time to pick up another new machine! 

It has to be said the Ali versions are quite a bit different looking to what you might get from your local supplier, this design seems much more common https://www.cab.de/en/electronics/pcb-separators/ (and is available with many badges on it). It is the way to go for V-Scored panels up to the point you have get routers to depanel your PCBs (maybe even laser ones).

I had a look around and that style is 3-4 times the price. I can't imagine it works that much better?

I don't see how it would be either, its just interesting how the Ali versions are so very covered in lots of bolts and knobs for adjusting things and the others have little to no such controls. Maybe when you have double sided boards or chunky bits of THT leads poking though on the other side the split table helps somewhat. The "western" ones also only come powered as a more expensive option.