flexible PCB's at home?

[evandude]

So, I know this guy, who tends to get some wild ideas, which aren't always very practical, but a while ago he told me he had figured out a way to make flexible PCB's at home.

his plan was to take aluminum foil and stick clear packing tape to one side of it, and then etch it like a normal PCB with toner transfer. Granted, his method doesn't seem like the most aesthetic approach, or the most reliable, and i'm not sure how solderable aluminum foil would be :lol: but he claims to have tried it on some simple design and had it work...

But, most importantly, his idea led me to look around at similar but better solutions, and I noticed you can buy thin copper foil for reasonable prices (such as a 12 foot roll of 1 foot wide foil for about $17)... and you could probably buy something like overhead transparency film except on a roll, and then you'd just need to experiment with adhesive. Or, for smaller boards, you could buy the copper foil tape (if you could find it wide enough)...

any thoughts?

 

[Nigel Goodwin]

So, I know this guy, who tends to get some wild ideas, which aren't always very practical, but a while ago he told me he had figured out a way to make flexible PCB's at home.

his plan was to take aluminum foil and stick clear packing tape to one side of it, and then etch it like a normal PCB with toner transfer. Granted, his method doesn't seem like the most aesthetic approach, or the most reliable, and i'm not sure how solderable aluminum foil would be :lol: but he claims to have tried it on some simple design and had it work...

But, most importantly, his idea led me to look around at similar but better solutions, and I noticed you can buy thin copper foil for reasonable prices (such as a 12 foot roll of 1 foot wide foil for about $17)... and you could probably buy something like overhead transparency film except on a roll, and then you'd just need to experiment with adhesive. Or, for smaller boards, you could buy the copper foil tape (if you could find it wide enough)...

any thoughts?

Aluminium doesn't solder well, you need special flux to do it (or solder with the correct type of flux in it's cores! - which you can buy).

The copper foil should work fine, but bear in mind the backing you use needs to be able to withstand the temperature of soldering!, as does the adhesive.

Why do you want to make a flexible PCB anyway?, they don't have many uses - about the only place you see them is connecting lamps in car dashboards. I can't see them been much good for fixing many components to?.

 

[padu]

A while ago I read something about Epson doing some research on flexible PCB. I don't know if they advanced their research though...

Basically what their doing is printing the PCB layers directly from an inkjet printer using a conductive silver ink. Read on

**broken link removed**


Also found the press release from their website

http://www.epson.co.jp/e/newsroom/news_2004_11_01.htm

 

[pandaemonium]

A few years ago I found some extremely thin double sided boards in a surplus store. I was told they are used for making multi-layer boards. Maybe you could find something like that. I made a circuit, rolled it up, and put it in a clear tube. Looked neat.

 

[roboticmisinfo]

Excuse my ignorance, but what is the use of a felxible PCB?

 

[pandaemonium]

I can't think of any valid uses other than aesthetics, thats what I used it for.

 

[evandude]

yes, aesthetics would probably be the best reason. sure, it's not practical for most stuff, as usually you want the PCB to provide rigid support for the circuit, but occasionally flexible would be handy... especially if you need to fit a PCB into an odd-shaped enclosure...

 

[RDL2004]

Flexible printed circuit boards have been used in cameras for many years. They can be bent and folded to fit in spaces where no rigid board could be used.

https://www.nikon.co.jp/main/eng/portfolio/ about/history/cousins/cousins10-e.htm

 

[roboticmisinfo]

I have honestly never heard of it before, but I guess I have never thought about it! Anyway, I guess it could be useful in things like Robots, where there are lots of moving marts, and odd shaped spaces (e.g. the joints on limbs etc) Still seems wierd though - why not just have a couple of smaller boards that would fit? lol

regards,

Mike

 

[jbeng]

I have been able to make those flex circuits at home, but you need to have the proper plastic film laminate. I happened across some several years ago from a surplus place (don't remember which one). It was copper laminated onto kapton plastic. Basically, I used the photo process to make them. First, I would [temporarily] fasten a suitably sized piece of laminate onto a piece of plexiglass (making it rigid like a pc board). I used the type of rubber cement like you would use in art class to do this. Then, I would coat the "board" to make it photosensitive. Expose, develop, etch and drill as normal. Peel the flex circuit off the plexi, cut it into shape and there you have it. Problem is, GC doesn't make the sensitizer spray anymore. (maybe someone else does?) Here's a link to duPont's flex circuit web page for the kapton laminate:
**broken link removed**
JB

 

[pike]

Well if you can shrink the thickness of the board, you could shrink the thickness of anything such as my neat as cell phone, the motorola v3 razr. its only 13 mm thick!!

The only other place i could think of is in the military or nasa where things have to be light and compact. Or maybe even on model aeroplanes where everything has to be superlight

Drilling holes will probably be a pain in the... SMD's might work!!

 

[evandude]

I don't think drilling would be a problem, if anything it'd be easier... less to drill through... just do it on a solid backing like a sheet of wood or plastic or something and you'd be all set.

 

[pike]

nah, ive drilled thin plastic sheets before. They tend to bend up and stretch. The only way to counter this problem was to sandwhich it between 2 chunks of wood, but then i would be drilling 'blind' holes. Too fussy. :?