Has anyone here uses RTR or other methods of making “infinitely” long FPCs? I’d like to make cut-to-length sensor tape, similar to cut-to-length LED strips. My customer would be interested in 1-5 meters at a time.
Splicing is an acceptable but undesired solution, but if I can do rolls I’d be a happier camper.
Trackwise in the UK do RTR flex PCBs. The company went under to some extent and were bought out by Amphenol so it’s now amphenol trackwise.
I’ve used them in the past for EV Battery FPC assemblies, but they were 500mm or so long so nothing crazy. I believe they started by supplying FPCs to Rolls Royce for aircraft engines - a lot of signals to get around a large engine perimeter with low packaging space & mass so it makes sense…
In 2010 I used a company inkjetflex.com (UK) and created about 50 2.5 GHz antennas and about 100 custom flatflex “cables” to transition between two connectors with different pin pitch. The cost was $60 for about 1 square foot of material. I used normal PCB tools (Altium) , with Gerber files as their input requirement. The base material was polyester (I think), 12" wide and up to 300 feet long and .004" thick. The copper was very thin (maybe .0001 thick), such that sliding your finger over copper and non copper areas you could not feel the transition. A single sided process with no through holes, vias, or overlay.Unfortunately even low temperature soldering exceeded the polyester substrate’s temperature tolerance. The above URL seems to be dead, but maybe it got acquired and exists under another name. It was fun to play with until everything melted.
In my own experience with LED strips, I’ve come across a bunch of rolls where they were soldered-together segments shorter than the roll length. I once saw a video where you can see distinct sheets of flex circuit being soldered together to splice sheets together. While trying to look for that, I came across this actual continuous roll LED production: https://www.youtube.com/watch?v=1sxwy2MHg-Y
(Toward the end of the video, though, there is one moment where they show splicing from one strip to the next.)
The video appears to be from a manufacturer of such a RtR production line? Perhaps an inquiry with them might be fruitful.
Found a different video where it’s done sheet-by-sheet: https://www.youtube.com/watch?v=fHplz2LPLbg