Flexible circuits

"Greg Wood" <greg.wood@NOSPAMshaw.ca> wrote in message

news:he6c2m$p4q$1@cheetah.cadsoft.de...

I've been using eagle for a number of years now and am reasonably

proficient with it.  Recently I've come accross an application where a

flexible printed circuit (FPC)  would be ideal.  I've never designed

these before.  What special considerations need to be made for FPC

circuits in eagle?  I've come accross a design guide for FPC which has

some good advice, but I have a few specific questions.  For instance

how do I show where cable stiffeners must be placed?

I never did a Flexiable circuit but, You can add a layer for the

stiffeners and in addition to the gerbers, provide a layout drawing

showing the placement of the stiffeners. I normally make a drill drawing

for quoting, so the stiffeners would become part of it.

Or you can just ask the vendor for what information he needs.

Cheers

Martin Eder wrote:

"Greg Wood" <greg.wood@NOSPAMshaw.ca> wrote in message

news:he6c2m$p4q$1@cheetah.cadsoft.de...

I've been using eagle for a number of years now and am reasonably

proficient with it.  Recently I've come accross an application where a

flexible printed circuit (FPC)  would be ideal.  I've never designed

these before.  What special considerations need to be made for FPC

circuits in eagle?  I've come accross a design guide for FPC which has

some good advice, but I have a few specific questions.  For instance

how do I show where cable stiffeners must be placed?

I never did a Flexiable circuit but, You can add a layer for the

stiffeners and in addition to the gerbers, provide a layout drawing

showing the placement of the stiffeners. I normally make a drill drawing

for quoting, so the stiffeners would become part of it.

 

Or you can just ask the vendor for what information he needs.

 

Cheers

 

 

 

I recently did a rigid-flex assembly (still not back from fab so I can't

claim success!) and ran into a couple of issues w/ Eagle and flex.

Regarding the issue of stiffeners,  I had a similar thing w/ the rigid

sections.    I created a separate library part for the rigid sections

and used the dimension layer only to show the flex boundaries.   Since

its a rigid-flex assembly you have more layers where theres a rigid

section but I did not figure out a good way to have Eagle take care of

this for me so I had to manually check.

A second thing is that for flex the power/gnd plan fill should not be

solid...the fabricators like cross-hatch.   Eagle can do hatch fill

polygons but these are always oriented with the x-y axes whereas for

flex layout you could like the cross-hatch on the diagonal.    Someone

in this forum suggested rotating the whole PCB by 45,  then ratsnest and

generate gerbers.    I then used my gerb editor to rotate everything

back by -45 degrees which gives me the diagonal fill pattern desired.

Jim