When you’re working with a manufacturer, how do you send them things like copper weights, preprag thickness, assembly instructions, etc, etc. At my last company we just put everything into a giant text file that we added to the zips that we sent. But I’m hoping that there is a better way!
not sure what’s the best way using other ECAD applications, but using altium designer which is my tool of choice, I find the best way is just to make a fabrication spec document manually. It’s boring and wastes a bit of time, but it works.
You can have some of the important info already in the altium PCB file, in the layer stackup manager and the design rules, but I never found a way to get it out nicely (that said haven’t looked for years anyway…)
Maybe this is something upverter could add as a part of gerber generation? a fab spec isn’t that tricky even for multilayer. You just need to specify the basic construction stack up, and link the gerber files by name to the right bits of the stackup, specify materials for everything, add your minimum width, clearance, and hole data and off you go…
Obvoiusly specific things like deliberate net shorts (ie loop antennas), discussing routed out areas, or solder mask open areas, as well as any kind of process control coupons would have to be explained manually - but you could still add a “specific fab instructions” field into the design somewhere to even hold that sort of thing.
You could treat the physical PCB as a collection of raw parts kind of like the components already are (specific cores/prepregs/foils/mask/finish/etc - with bog standard preset materials for the noobs and the unconcerned) and have that captured in the design, then pop out a standard format .doc at the end. Might also want to pop out a paste screen spec while you’re at it?
It makes sense to me to pop out fab spec files fresh every time you regenerate the CAM files. But really it’s going to depend on how someone runs configuration management at their company, and how they want to relate design files with CAM data, or even design process with manufacturing process… It’s very hard to come up with a single approach that will suit everyone - ask altium about how their vaults thing has gone…
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So, we’ve already started down this road by adopting the OshPark naming convention for Gerber and drill files.
I really like some of the options you’re mentioning for identifying net shorts, etc. Config mgmt is definitely going to be bright on our radar.
We generate a FAB or Master Drawing with the dimension notes etc.
The notes are in the form of a text template with all our notes. Then we just delete the ones that don’t apply do a search and replace for things like Part Number and Material and paste it into the drawing. For the stackup we have a tools that creates the cross section and lables it. That gets pasted into the drawing as well.
One document covers the whole board and it’s quick and simple.
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