Getting flexible circuit boards made - diyAudio
Go Back   Home > Forums > Design & Build > Parts

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 19th June 2011, 10:22 PM   #1
diyAudio Member
 
Bob Richards's Avatar
 
Join Date: Feb 2011
Location: Portland Oregon, USA
Default Getting flexible circuit boards made

People tell me that flexible circuit boards are too expensive, but I probably need to submit a design and get a quote to know. I need it for the thinness more than the flexibility. It would be part of a front panel "sandwich" and hold 20 tri-LEDs for panel lighting. It would have frosted plexiglass over it, and a brass plate over most of the plexiglass. Is there a good place out there, in the USA, that's not horribly expensive? I would want only a quantity of two for now. And I get the impression that the design has to be in "Gerber file" format for them to be able to work with. How do you generate a gerber file layout without spending thousands on the software for that? Maybe I'm in over my head. I want a preamp front panel that is an art object, not some black on black button panel like so many appear to be these days.
  Reply With Quote
Old 20th June 2011, 12:09 AM   #2
diyAudio Member
 
Join Date: Mar 2007
Location: Canandaigua, NY USA
Yes, flex circuits are quite expensive if you only need a few, far beyond hobbyist prices. Almost any board house should be able to give you very thin conventional board material much cheaper than flex. You need to do a layout in something that supports Gerber output. I use TinyCad and FreePCB from Sourceforge, both of which are free. There are various other inexpensive choices and a search will get you lots of discussion as to which is better. Expect a pretty steep learning curve if you haven't done PCB layout before. Not quite vertical, but steep.
__________________
May the root sum of the squares of the Forces be with you.
  Reply With Quote
Old 20th June 2011, 02:12 AM   #3
diyAudio Member
 
dchisholm's Avatar
 
Join Date: Mar 2011
Location: St Louis, Mo
Yes, truly "flexible" circuit boards are expensive. In a prior incarnation, my employer solved the requirement for a small, and very infrequent, PCB flexure by using a very thin PWB material and placing components so they avoided the areas where the flexing occurred.

Assuming I understand your design concept correctly, may I make a suggestion?

Plexiglas (and similar acrylic materials, like Lucite and Perspex), and Lexan (polycarbonate) are both easily machined with common woodworking tools. After a little practice with a router mounted on a (preferably homemade) router table, you should be able to mill a "pocket" into a sheet of Plexiglass and hide the PCB assembly in the milled-out area. If the function of the plastic sheet is primarily for visual aesthetics, rather than structural rigidity, you probably need only 1/16" or less of material left over the LED's. If you start with, say, 0.250" sheet stock that means the pocket depth could be as much as 3/16".

Dale
  Reply With Quote
Old 20th June 2011, 03:38 AM   #4
diyAudio Member
 
dchisholm's Avatar
 
Join Date: Mar 2011
Location: St Louis, Mo
Although a few vendors who specialize in quick-turn, run-of-the-mill prototype boards require you to use their own no-charge, proprietary, on-line layout software - the "real" board vendors will require Gerber plotting files and an Excellon drill file. Fortunately, everybody in the industry knows this and all the PWB layout packages can produce these files. (Having said that, there are several variations of "Gerber files" and you'll need to find out from your board fabricator exactly what he's expecting and adjust the options in your PWB software accordingly. The "Gerber file" format itself has an interesting history dating back to the 1960's - long before it was used to fabricate printed wiring boards.)

Learning PWB layout software DOES take a little effort and some time. Part of the process is just learning the jargon - even terms that seem to have well-defined meanings in common usage may have a much more restricted definition within a PWB program. You also must appreciate that a printed wiring board is much more than just a place to park your parts, and some of your frustration comes from the software's attempts to satisfy the many requirements of a system that is MUCH more complex than a few copper conductors running across a piece of plastic. One thing that surprised me was the amount of time I spent doing "library work" - creating symbols and padstacks for the components I used - even though the programs came with extensive component libraries. This may be because the PWB fabricator has preferred sizes for drill holes and/or solder pads.

I have done boards using 4 different commercial programs. Each is different, but I would be hard pressed to say that one is truly "superior" to the others. Each required some practice and learning time before I could do really high-quality work with it - even though I had previously used other programs. I was always able to get help from online support forums, both company-sponsored and unofficial.

I haven't used any of the no-cost or hobby-oriented layout software. (I have one of the expensive (but rather outdated) commercial packages, courtesy of some consulting work I did several years ago.) I have noticed that many hobbyist and part-time freelance designers like the "Eagle PCB" program from Cadsoft. It's available in a variety of capability levels, with prices ranging from "no cost" to a few thousand dollars a copy (that's CHEAP by commercial standards!). Many hobby users have created tutorials and Youtube videos to help other users. "Kicad" is another popular package, developed as an open-source project. I believe the Student Version of "Multisim" also allows you to create simple PWB layouts.

And . . . you may want to look at "Latest version of PCBCAD40 now here.", on this Forum!

Dale
  Reply With Quote
Old 20th June 2011, 07:29 PM   #5
diyAudio Member
 
Bob Richards's Avatar
 
Join Date: Feb 2011
Location: Portland Oregon, USA
Thanks much for the advice. The best idea I have right now is to use a conventional circuit board and attach it to the back side of the front panel aluminum "substrate", with holes drilled in the aluminum panel to let the light shine through into the plexiglas on the front side. Even that will cost a bunch, but it's the best idea I can come up with so far. It will need to have cutouts for all the knobs and switches (since their bushings can't handle a thick front panel).
  Reply With Quote
Old 20th June 2011, 07:41 PM   #6
diyAudio Member
 
firechief's Avatar
 
Join Date: Sep 2008
Location: Near Seattle Wa
dchisholm's comments are spot on. I would add that board layout is fun and rewarding. If you are a nerd.

Oh and Kicad offers both schematic capture, and PCB layout. There is a learning curve like all of them, but there are no restrictions on the free version. Good stuff.
__________________
"You can keep your insurance baby nothing is guaranteed" -Tom Petty

Last edited by firechief; 20th June 2011 at 08:03 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Questions about a circuit to made a IV amp filter tessier Digital Line Level 0 3rd May 2011 07:26 AM
The best Amplifier circuit ever made. destroyer X Solid State 120 20th November 2008 05:26 PM
Ribbon made of flexible flat cable APi Planars & Exotics 7 21st July 2005 11:59 PM


New To Site? Need Help?

All times are GMT. The time now is 01:41 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2