How about metal core PCBs? Example. I've used them for high power LEDs, and we etched in house using basically standard processes. Of course the do place limits on your design (and they're annoying to hand-solder), but if you can get away with double-sided boards they'll give you a solution that will disssolve in anything your Al case will dissolve in.

The insulating layer is typically 100 µm thick, but I'm struggling to find out what it's made of. This is the one we bought. I'd assume that if surface-mount components can be dealt with, so can small pieces of polymer insulation. It could be scored by routing, slotting the board, or even by hand with a scriber so that it breaks into smaller pieces (I don't know whether this is a research 1-off or a production run)

You should reconsider metal core PCBs Example. I've used them for high power LEDs, and we etched in house using basically standard processes. This is the one we bought.

Of course they do place limits on your design (and they're annoying to hand-solder), but they can be double sided (example from the same supplier as above, not someone I've ever used). They'll give you a solution that will dissolve in anything your Al case will dissolve in.

The insulating layer is typically 100 µm thick, and it appears to be epoxy-based prepreg. I'd assume that if surface-mount components can be dealt with, so can small pieces of polymer insulation, which are likely to break up. It could be scored by routing, slotting the board, or even by hand with a scriber so that it breaks into smaller pieces (I don't know whether this is a research 1-off or a production run, so I don't know what processes are plausible).

How about metal core PCBs? Example. I've used them for high power LEDs, and we etched in house using basically standard processes. Of course the do place limits on your design (and they're annoying to hand-solder), but if you can get away with double-sided boards they'll give you a solution that will disssolve in anything your Al case will dissolve in.

The insulating layer is typically 100 µm thick.

How about metal core PCBs? Example. I've used them for high power LEDs, and we etched in house using basically standard processes. Of course the do place limits on your design (and they're annoying to hand-solder), but if you can get away with double-sided boards they'll give you a solution that will disssolve in anything your Al case will dissolve in.

The insulating layer is typically 100 µm thick, but I'm struggling to find out what it's made of. This is the one we bought. I'd assume that if surface-mount components can be dealt with, so can small pieces of polymer insulation. It could be scored by routing, slotting the board, or even by hand with a scriber so that it breaks into smaller pieces (I don't know whether this is a research 1-off or a production run)