Flex Circuit

[brent_e_barbour]

In Inventor 2019, I'm modeling a flex circuit. The closest thing I found in the "Cable and Harness" environment is the ribbon cable with is not the same thing as a flex circuit. So, I used the "Sheet metal.ipt" template adaptive to the connectors in the assembly. However, I now want to unfold and flatten my flex circuit for the drawing. I can flatten the sheet metal .ipt file but not at the assembly level with the connectors. The only way I can figure out how to do this is to export all my views to an AutoCAD DWG and move the connectors to the flat pattern. However, I lose my associativity. Is there a better way to do this. See attached screen capture of my flex circuit. Thanks, Brent

[mcgyvr · Accepted solution]

Make the sheet metal ipt an ipart.. One with all of the bends computed and another member with unfolds to just be flat..

Your assembly would then become an iassembly..

[brent_e_barbour]

Interesting solution. However, I can't seem to get it to work so I attached my files. Perhaps you can take a look and explain it further? Thanks, Brent

[johnsonshiue]

Hi Brent,

In my opinion, I don't believe iAssembly or iPart is the right solution to your problem in this particular case. iAssembly/iPart are meant for creating library component. What you are trying to do is so-called in-context configuration. It means component geometry has mutual dependency within the assembly for each configuration. The best workflow for this kind of design I believe is using iLogic and iLogic Design Copy.

You focus on building one design. Next you use iLogic rule to drive changes. Then you use iLogic Design Copy to make a copy of the new configuration.

Many thanks!

[swalton · Accepted solution]

I just did a similar task with PTC Creo. 

Anyway, I think I understand what you need.

I don't think you need to use a cable/harness assembly/part.  Normal parts and assemblies will be fine.  I think trying to make the FlexPCB part adaptive to the location of the electronic devices is not helpful either.  You want the devices to move with the part as it is flattend, so they should not be driving the shape of the FlexPCB.

Use an iPart with sheetmetal features to build the formed and flattened PCB.  Instead of using the Flat Pattern command to show the flat state, use an Unfold feature at the end of the model tree.  The Unfold feature should be controlled by the iPart table.  You will have three total part files:

• FlexPCB-Factory.ipt
  • Used to design the PCB.  Not used in any assembly or drawing file.
• FlexPCB-Member-Formed
  • The 3D FlexPCB shape.  Used in the Flex-PCB Formed iAssembly member
• FlexPCB-Member-Flat
  • The flattened FlexPCB shape. Used in the Flex-PCB Flatted iAssembly member

Try a sheetmetal k-factor of .5.  That should minimize the stretching of the PCB material as it is flattened.  

When you are ready to add the connectors, create a new iAssembly factory file.  Place FlexPCB-Member-Formed in the assembly.  Add the connector parts and constrain them to the ends of the FlexPCB part.  In the iAssembly table you will add a member to show the flattend PCB.  You may have to add new constraints or new connectors to get them to move when you change between the Formed and Flat versions.

You will have three assemblies on disk:

• FlexPCB-Factory-iam
  • Used for design and controlling the iAssembly members
• FlexPCB-Member-Formed.iam
  • Used in upper level assemblies to show the routing of the PCB.  You may show this formed assembly on your FlexPCB 2d print.  That way you can dimension the 3d shape and let your PCB vendor control the flat shape.  Remember the 3d shape is the important one unless you are actually manufacturing the PCB in-house.
• FlexPCB-Member-Flat.iam
  • Used in 2d prints to show the flat layout.  You may also include a copy of FlexPCB-Member-Flat.ipt so that your vendor has a cut file.

[mcgyvr]

---

@brent_e_barbour wrote:
Interesting solution. However, I can't seem to get it to work so I attached my files. Perhaps you can take a look and explain it further? Thanks, Brent

---

@brent_e_barbour 

Try what @swalton  posted above.. Thats a good breakdown of the basic process..

And see attached... This demonstrates it.. Open FlexPCBAssy.iam and change between the 2 members,etc...