topic Re: Reverse Engineering a simple Flexi Circuit in Fusion Electronics Forum

Reverse Engineering a simple Flexi Circuit

formsR28H6 — Tue, 05 Oct 2021 04:13:11 GMT

Hello all;

I need to re-manufacture the flexi circuit in the picture below.

I have been using DipTrace for probably 15 to 20 years, but figure that this would be a good application for F360.

How would I go about this ? - If I created a schematic, which would be a simple pin-to-pin connection, how would I go about designing the male connectors on each end ?

I guess that I would create the flexi outline, and then just do routing as normal ?

Any help would be appreciated

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Tue, 05 Oct 2021 11:50:04 GMT

I have made some progress.

I created a sketch and then exported that to a 3D PCB for the outline of the flexi circuit.

Then I created a new Library, added a new edge connector footprint, symbol and device and linked the footprint to the symbol.

Then I added 2 of these edge connectors to my schematic and linked up the nets and pushed it to the PCB.

But F360 refuses to allow me to place these edge conns on the PCB, I can move them anywhere around outside of the profile but simply cannot place them on the PCB.

If I add a component from one of the standard libraries, then I can place it on the board, but I cannot place my custom edge conn on the board and just cannot figure out why not !

What have I done wrong ??

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Tue, 05 Oct 2021 12:13:24 GMT

OK, I have switched off violators and now I can place the edge conns on the board, but is my approach the correct way to do this for a flexi circuit ?

Re: Reverse Engineering a simple Flexi Circuit

jorge_garcia — Tue, 05 Oct 2021 20:16:34 GMT

Hi @formsR28H6 ,

I hope you're doing well. Since these are edge connectors you'll have to disable the violators to put it right on the edge because by default a minimum separation is enforced. Setting ignore violators allows you to bypass that minimum separation.

Let me know if there's anything else I can do for you.

Best Regards,

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Tue, 05 Oct 2021 23:42:43 GMT

Thanks, but I already figured out to disable violaters in my post above.

What I am trying to determine is the approach to creating flexi circuits as I have not found any tutorials or snippets / instructions on how to create flexi circuits.

In a PCB, the copper layers are either side of the board, but in a flexi circuit, the tracks are sandwiched in the moddle, and there are backers that cover the rear of the edge connectors.

What I am interested in is how to create a flexi circuit as opposed to a PCB, and if someone has an example of something they created this may help me understand how its done.

At the moment, treating this like a PCB is just not going to work 😞

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Wed, 06 Oct 2021 10:47:37 GMT

@jorge_garcia - would it be possible to create a simple tutorial on creating FPC flexi circuits as there appears to be nothing that I can find.

I did find (and found it very useful) your video on how to transfer a sketch (robot man) into a 3D PCB 🙂

Re: Reverse Engineering a simple Flexi Circuit

jorge_garcia — Wed, 06 Oct 2021 22:48:01 GMT

Hi @formsR28H6 ,

The things with flexible PCBs in Fusion 360, is that it's not really a supported workflow. It can be done with workarounds, but it's not very nice. Basically, you end up have to take some of the layers and say ok, this layer is going to represent this and this one is going to represent this other feature. Then you have to be really careful when you export the gerbers.

Ideally we would make a tutorial once we have some official support in the tool for it.

Let me know if there's anything else I can do for you.

Best Regards,

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Thu, 07 Oct 2021 00:40:28 GMT

Thanks, well I guess the chances of this being added are pretty remote, given that I am unable to find anyone asking the same questions.

Would you able to create a simple example that I could use to figure how to go about doing this. Actually, in terms of complexity this is pretty simple as it is just a single layer using 2 standard 0.5mm pitch x 8 edge connectors ?

I have searched here and on google and are really stuck, other than defining the profile outline and the backers, I really don't know how to proceed from here ?

Re: Reverse Engineering a simple Flexi Circuit

formsR28H6 — Sat, 09 Oct 2021 11:03:19 GMT

How would you setup the layers, as with a FPC the copper layer is in the middle, there seems to be no way of doing this ?

Re: Reverse Engineering a simple Flexi Circuit

rhdfmail — Mon, 18 Oct 2021 15:03:52 GMT

The important thing would be how the boardmanufacturer wants the gerbers
As I understand it its basicly a 1or 2 layer board made of "plastic" instead of FR4. And instead of normal soldermask its a protective outer plastic layer and that is a part of the process.

This makes me think that you should be able to send a gerber for a 1 layer board and specify it as a flat-flex board