Rapid Prototyping Tool for PCBs

Discussion in 'The Projects Forum' started by CarlosO, Jun 23, 2014.

  1. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    Hello All.
    I'm working on a project with a friend. We want to create an all-in-one machine that can quickly prototype most circuits a hobbyist would build. The machine will use conductive ink to print on different substrates, conductive glue to attach the parts and a simplified pick-and-place head to assemble the board.

    After months of work we have a prototype, but we want to know if what we've built is actually what the community wants. We want to build something worthy of being used by most of us.

    What experiences have you had with rapid prototyping of PCB boards? Can you tell me what your likes and dislikes are?

    If you want to know more about our project, you can find it here: http://botfactory.co
     
  2. atferrari

    AAC Fanatic!

    Jan 6, 2004
    2,648
    764
    Deleted message
     
    Last edited: Jun 23, 2014
  3. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    I think it's a very commendable project, and if it worked it could be very useful. :)

    I'm not sure how you will sove all the technical problems. I've worked with conductive silver paint in the repair industry and it is not very reliable, goes hard real quick and gums up nozzles and I would not count on it for full circuit assembly. Especially things that get hot and have thermal expansion which breaks the conductive paint.

    Also you will have issues with PCB density, unless you have a way of making double-sided (multilayer?) PCBs. Single sided PCBs are almost useless these days unless you are prototyping a 555 LED flasher.

    And how are you going to affix fine pitch ICs etc to fine conductive paint tracks? I have a pick and place machine and it needs to reflow in the oven to get good alignment, trying to get good intitial alignment will be hard for you unless you have full (top/bottom) camera alignment system.

    Then you will have issues with mechanical strength of things like connectors and heavy components etc.

    Anyway I think it is a wonderful idea; a machine that makes the PCB and populates it all in one operation. Very cool, very SciFi.

    But at this your page looks more like an ad, a vapour-ad. Do you have any actual machinery, or hardware testing? At the moment it looks like you have a plotter drawing on paper.
     
    CarlosO likes this.
  4. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,131
    267
    If I am prototyping a PCB design, I am usually at a stage where I have to beat the crap out of the board, I usually get something wrong, need to 'roach wire' something new in, or change a component.

    The idea of doing this with conductive glue sounds like a disaster, I need to be able to modify and solder on the board, it needs to have predictable electrical and thermal characteristics that match a production PCB and it needs to be very robust.

    This concept would appeal to those with "makerbot fever" but they will quickly abandon the idea once they discover the real compromises they have to live with.
     
    OldSkoolEffects likes this.
  5. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    You're absolutely right, there's a bunch of technical challenges that need addressing. We have put together a bunch of ideas to solve some of them, for example:
    - The case of pick-an-place alignment, in which case we're using Computer Vision to get the right alignment.
    - Pitch: we are using inkjet printing, so we can go to very small features. We're kind of limited to SOIC at this point, but we don't see it as a long term road block
    - Multilayer: Well, there's plenty to be said here, but I won't because that would raise your hopes, and we're not there yet. One thing I can say is that it's absolutely doable, and once its done going from 2 to 32 layers is going to be a piece of cake.

    The boards are of course, fragile. They shouldn't be used out of the lab (unless the lab is your house :))

    By the way, regarding the website: What give you the feeling of a vapour-ad". Do you think a video of the printer working on a circuit would solve this?

    Thanks for your feedback.
     
  6. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    Thanks for your comment.
    The way we imagine our technology at work is that you will print a new circuit every time you're ready to test your changes. Minor reworks can still be done because you can solder to the board as usual.

    Does it make sense to you now, or do you still think is not going to cut it for you?

    Carlos
     
  7. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    years aog, when trying to repair some tactile keyboards for video games (the quarter grabber kind) I found some silver paint, nickle paint and copper paint, all of whitch were conductive enough for pc board repair. the keyboards were flexable, and didnt like to be patched up very much. all three of the paints were solderable after drying a while. I dont remember the brand names of the three paints, but the silver paint smelled like banannas when used.
     
  8. OldSkoolEffects

    Member

    Nov 18, 2009
    68
    1
    So you wouldn't be able to do any though-hole? I commend the idea, but the end product seems like it would be fairly fragile compared to what I can get in a few days from a board-house.
     
  9. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    $50.. really? I think you forgot at least one "0"
     
  10. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    My house IS a lab. ;)

    Firstly, I only had a cursory glance at your page so please forgive me if I missed something.

    What I would expect to see if your machine worked;
    * Details on the conductive paint (resistance per inch for track widths etc)
    * Photos of working PCBs, with parts and paint and LEDs flashing etc
    * Details of the mech problems like how wires are attached to the PCB

    The impression I got from that quick first glance was that you are working on the technology, in a very early stage of development.

    Photos and videos of working, actual PCBs would be worth a LOT.

    Remember the old advertising saying; "Don't sell the steak, sell the SIZZLE!". People want to see the RESULTS from the machine. Working useful PCBs.

    Good luck with the project. :)
     
    CarlosO likes this.
  11. Sensacell

    Well-Known Member

    Jun 19, 2012
    1,131
    267
    Every change then requires a total re-make of the board? I need to stock all the parts for N iterations of the design? and debug each board anew?

    That is slow and expensive!

    In my experience, the time it takes to have a board made by a conventional board house is not a major factor in the design cycle, I rarely say to myself: "if only there was a faster way"

    Most errors and changes can be corrected by clever cut and jumper rework tricks, this is fast and cheap- as long as the board holds up.

    what matters most to me is the quality of the board itself, once you have a pad lift on a crappy PCB while you are reworking something- you then understand this viscerally.
     
    CarlosO likes this.
  12. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    I completely get what you're saying, fixing a broken board is a complete waste of time.

    The question is: Do you think the current process is optimal? Are you getting to your final product as fast as you actually can?

    It sounds like you've been in multiple projects and I may not be seeing the full picture here, so please consider my question and tell me: What would be your biggest pain when designing electronics?
     
  13. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    Are you talking about the home page? :)

    Actually, we should remove a 0. The cost of manufacturing a prototype (PCB and assembly), given its about 5"x 5" and its printed in paper, is around US$5. (components not included)

    Of course the cost of the printer has to be amortized, but I guess the really important factor here is providing enough value for whoever uses the machine.

    Does it make sense?
     
  14. Alec_t

    AAC Fanatic!

    Sep 17, 2013
    5,800
    1,104
    I can't see that surviving long :(. How will heavy components, edge connectors, cables, switches etc be supported so that there's no mechanical strain on the circuit tracks?
     
  15. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
  16. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    You said about using "dots of conductive glue" to secure and connect the components?

    [​IMG]

    I can see a wealth of problems here. What is the set time of the glue? You will need to swap the machine head from glue to PNP, then set up all the tapes and feeders for all components on the PCB. On my PNP machine that can take some time, it's a very fiddly job dealing with the tapes and their cover tapes and the very important triple-checking the right tapes are int he right places... ;)

    Then another problem is that many SMD resistors, caps etc have the component lands on the very ENDs of the component. That relies on reflow to get the wet solder to rise up the ends of the component. Glue under the component won't cut it.

    In my opinion you really need to make some PCBs with multiple parts on the PCBs and start sorting out all the problems that you will surely encounter. Even after my PNP machine was built it tooks months of re-designing and refining tape feeders so it would work reliably without constant supervision.
     
    CarlosO likes this.
  17. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    Thanks "The RB", your comment is really good.

    I'm going to answer some of the questions, and then get back to the design board taking into account your feedback.

    1) Set Time: We're using a special mix. If you leave the glue unattended it will take around 6 hours to solidify. If you apply little heat (that's why we plan to add a heat-bed) you can cure the glue in 10-15 minutes.

    2) Rails and PNP: We're trying to avoid using rails (tape) because it may take longer to setup the PnP system than building one circuit. Our focus is prototyping, so we don't intend to print 10+ circuits in a batch. Instead, we're providing a tray with slots that the user can populate with parts. We're currently working in the process of taking a component from a tape, and place it on the tray.

    3) Connectors at the ends: Good point. We'll have to check this.

    I hope this helped.... Running to talk to my team now.

    Thanks!
     
  18. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    Thanks for the answers.

    I look forward to seeing your results. :)
     
  19. CarlosO

    Thread Starter New Member

    Jun 23, 2014
    8
    0
    Hello Everyone,
    Just wanted to tell you we're planning to go for crowdfunding soon.

    If its not too much to ask, would you mind supporting us by allowing us to post ONE message on your facebook wall? It would allow us to create a synchronized wave of posts the day of launching our campaign. You just need to go to this link and click the facebook button:

    http://thunderclap.it/projects/13377-squink-your-circuit-factory

    Thanks so much for your time and help. Your feedback is invaluable.
     
Loading...