Tab Routing

[jg_geadinc]

Does anyone know the best way to setup a design to use tab routing? I have a design that has a cutout where a switch mounts and I would like to have a PCB that mounts to the switch be the cutout. That way the switch can be 'wired' during assembly and they when it comes time to mount the PCB in the chassis, the switch PCB is broken away and soldered to the switch. This has to be done because the switch bottom is at a slightly different level and angle. But I'm not sure how to define it. If I use cutouts then that adds a significant cost to the boards at Sunstone. But if I can just define it to be part of the outline routing, it really isn't a 'cutout'. 

[jg_geadinc]

I guess that any route that is inside the board outline is considered a cutout so that part does not make any difference but I'm having trouble figuring out what is the best way to define the initial route that will come in from the board outline as the breakaway tab and mouse bites will be around 50% of the way in. Any suggestions would be appreciated. 

[RenKylo2]

Hey jg_geadinc,

What have you tried so far? Can you attach a quick diagram of your PCB setup?

[jg_geadinc]

This is what I have done so far. I put it all on the board outline layer and have drill holes by all the bridges. I've sent it in to Sunstones DFM reporting service to see what it comes back with. I get a bunch of DRC errors this way though. Telling me:

Design rule error: Two objects without nets are too close to each other.
7 times. 

[RenKylo2]

What you are doing doesn't look wrong. Give this KB a try, I think it address the error you are seeing. 

[jg_geadinc]

Except it did not come back from the DFM check clean. It only recognizes the cutouts around the board outline. i.e. the 2 internal cutouts did not show as being routed. 

The clearance check does not help as it does not show me where the error lies. The red error 'circle' is around the origin so trying to sort out of all the clearance lines which ones are violating the rules is next to impossible. 

[jg_geadinc]

I did figure out what was causing the DRC errors. It was the drill holes for the 'mouse bites'. I had placed a few too close to a couple of pads on the board. It will show me where the error is if I place those holes too close to the board edge but if I place them too close to a pad it gives that general error and places the error marker around the origin. Not much help.