Rigid-flex, How to document where flex starts en ridgid end?

[implor]

This is my first Rigid-flex card that isn't a straight piece of flex.

Now when i'm doing the production files I don't really get how the fab should know where the rigid part ends and the flex start.

Do you really have to do a detailed mechanical drawing to show the flex shape and dimensions?


also. How do the FAB know how the coverlay should look like? I can't find that as a layer in the Altium gerber settings. Do they just fixa it them self? I have coverlay in my flex stack.

[Berni]

Layers are just separate layers in Gerber. There is no firm standard on what layer what goes. For the classical layers like copper and overlay a lot of tools use similar names, but not always. For example in multilayer boards the PCB house often wants you to specify the exact order of the layers to make sure they get it in the same order as your PCB software intended.

In general the mechanical layers in gerber are for any miscellaneous drawing that does not fit anywhere else. They might have names like G1 GM1 M1...etc where the number is just the index of it. For Altium Mechanical 1 2 3... get put into those

Since these layers could contain anything means its a good idea to also include some instructions on that layer for what it is for. For example if i want Vcuts i will typically draw a line on one of the mechanical layers and place the text "V CUT" next to the line. For cutout holes i will typically place the text "Cutout" in the middle of it to make it clear. These layers could also just contain other text instructions like telling them not to place the board identification code in a certain area, it could contain instructions for penalization. etc

Just make sure any instructions are as simple as possible so that you don't confuse the Chinese workers at the PCB plant.

[implor]

All right.

Then I could do a mechanical layer drawing and show where all flex-rigid transition points are.

Better to have that on a gerber layer then a PDF file.

How about the coverlay? how do the fab know where to put it? Or do they add it over all the flex area?

[Berni]

Yeah its best to just include it all in gerbers.

For overlay you might want to check your particular PCB house because it might not be possible to have overlay on both simultaneously.