Is it possible to use SMD components on a home made pcb?

Discussion in 'General Electronics Chat' started by electron_prince, Mar 8, 2013.

  1. electron_prince

    Thread Starter Member

    Sep 19, 2012
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    is it possible to develop a printed circuit board by toner transfer method to use with SMD components? I have little to no knowledge on these stuffs. All i know is how to etch a board. These days i am trying to learn 'Eagle'. and I want to design my first pcb layout with SMD components.
     
    Last edited: Mar 8, 2013
  2. nerdegutta

    Moderator

    Dec 15, 2009
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    Hi.

    Yes you can. This is one of my boards. It's designed in Eagle. :)

    [​IMG]
     
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  3. crutschow

    Expert

    Mar 14, 2008
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    Certainly. You just need to find or generate the pad layout for each of the components you want to use. Most of the common ones are likely already in Eagle.
     
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  4. electron_prince

    Thread Starter Member

    Sep 19, 2012
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    wow, it's looking great. I am currently reading an article on "how to solder SMD components on board" and that tutorial started with "Making your own solder paste stencils". and that sounds really, really intimidating. Is soldering an SMD components on board difficult?
     
  5. MrChips

    Moderator

    Oct 2, 2009
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    Not at all. I stick to 0805 resistors and capacitors and SOIC ICs when available, as shown in nerdegutta's photo.
     
    Last edited: Mar 8, 2013
  6. nerdegutta

    Moderator

    Dec 15, 2009
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    Thanks. Like MrChips, I use 0805.
     
  7. Markd77

    Senior Member

    Sep 7, 2009
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    No need to use a solder paste stencil, or even solder paste. It can be done easily enough with fairly fine solder and a soldering iron with a small tip.
    I now use solder paste applied to the pads with a toothpick then a hotplate.
    Of course for a very large board, or if you want to make many copies, then using a stencil would save lots of time.
    <ed> If you are going to solder by hand, get some flux and some solder wick </ed>
     
  8. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Solder paste is a pain to use for just a few parts, but leans towards essential for even small production runs. Using a syringe for paste once took me a week for my thumb to heal after assembling a medium complexity board: it's tough to squeeze that stuff out manually!

    But without a reflow oven I'd still keep away from paste and use my spool.

    I keep a spool of .015" solder for my hand work, along with the smallest tip my iron can handle. To get a part down tin ONE pad for each device, then hold the part there with tweezers and reflow the tinned side. Then go back and solder the rest: that first connection will hold the part for you. IC's help if you do opposite sides first.

    For the inevitable shorts get some solder wick: I use .05" pre-fluxed wick to, well, wick up excess solder.

    I far prefer SMD parts even for prototype breadboarding. 0805's land nice on 0.1" pads as do SOT-23 transistors, and I keep adapters for IC's in my parts box to get them to fit on 0.1" centers too.
     
  9. Markd77

    Senior Member

    Sep 7, 2009
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    For hand soldering I use a "helping hand" to hold the part in place after putting a bit of flux on the board, then just go round with iron and solder.
    [​IMG]
     
  10. MrChips

    Moderator

    Oct 2, 2009
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    Interesting how everyone has their own techniques.
    I melt a tiny bit of solder on one pad only, ICs, resistors and capacitors.
    Then I hold the component down with something, maybe the tip of tweezers, then solder that one connection to hold it into place. Then I go around and solder the remaining pins.
     
  11. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Cheap hot air rework gun (under $100) or just a soldering iron (much tougher though than hot air) and some solder paste in a syringe..
    Stick with 0603 or larger components if you can..
    I just had to hand solder about 50+ 0402 resistors by hand plus some other small IC's and it was fairly tough.. But I did it.
     
  12. nigelwright7557

    Senior Member

    May 10, 2008
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    It depends on the size fo the components and their pitch.

    For DIY I much prefer through hole components.

    I have had trouble with normal soldering irons and SOIC 8's. My soldering iron was cooking them. So I bought a temperature controlled soldering iron and that worked much better. Also I found flux fluid a great help in preventing blobbing of the solder across numerous pins.
     
  13. takao21203

    Distinguished Member

    Apr 28, 2012
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    I use a rectangular tip + 1mm solder. SOIC and TQFP44 are very easy.
    Flux paste as well for TQFP44.

    6pin SOT23 is a bit difficult or also TQFP64, TQFP80 and TQFP100. For these a desoldering pump is handy.

    There is a technique called drag soldering. You pull a solder ball with the rectangular tip accross the pins. SOIC is a matter of seconds. Remember if you used a desoldering pump, apply flux and go over the row again + look with a magnifying glass.

    TSSOP take one or two minutes + needs flux.

    0805 resistors or LEDs really are best to be soldered with reflow. Baking oven with infrared grill on.

    Really soldering individual SMD IC pins is a hassle, takes very long, and it is not worth the effort. Try a rectangular tip and you'll see yourself how easy it is.

    Point tips can't pull solder away but it also works for regular soldering. Bridges are no longer a problem, can be removed with the tip in most cases.

    Cheap chinese lead solder is much worse for difficulty sometimes I find it even hard to solder regular 2.54mm with that. The flux isn't so good. I'd recommend to stick with western brands. Farnell has some discount stuff. If you pay $12 or $15 for a 100g spool, that's too much. The chinese stuff costs $4 to $5/100g.
     
  14. Uber_Goober

    Member

    Jan 19, 2013
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    I recently built 6 prototype boards for a project I'm working on. Although I've tinkered with electronics my whole life, its the first time I've made a PCB and the first time I've used SMD parts. I figured I had a 50/50 chance of success.

    I started to look at toner transfer methods etc, but then discovered BatchPCB.com. If you don't mind waiting for them to get made, its just so cheap that it doesn't even make sense to try to make them myself. I also got a solder stencil made at Pololu.com for about $45 (a lot more than the boards cost). Still cheap enough that I didn't have to worry about it.

    The funny thing is in the learning process, I didn't really know the difference between the component sizes. I ended up with a bunch of 0402 and 0603 parts on my board because I didn't know what I was doing. By the time I realized what I'd gotten myself into, I figured my odds of success were now about 20%.

    I also tried to get elaborate with temperature control. A lot of people use toaster ovens or hot plates/burners to reflow. At sparkfun.com, they say they had better results with a burner (a skillet actually) and they seem to know what they're doing. So I got a little burner. But I wanted to be all high-tech and got a PID controller (designed for kilns, but allows ramp/soak control times in seconds) and a thermocouple. I got it all wired up and programmed. The PID controller is awesome, but utterly useless for this project. The burner can't heat up fast enough to match the spec'd solder profiles. So I just switched to an optical closed loop process control system (my eyeball). I put the boards on the burner (I also have a 1/4" thick aluminum plate on it to avoid putting the boards directly on the hot coil). Then I cranked it up and waited for the solder to reflow. It takes a few minutes from ambient, but every time it reflowed perfectly. After the biggest pads finally went shiny I waited a few more seconds then carefully removed the aluminum plate.

    The result was 100% success. All 6 of my boards work and don't have any shorts or bad connections or melted parts or any problems at all. I'm still a bit giddy over the whole thing actually.

    So if I can do my own SMD at home you can too. But its so cheap to get boards professionally made now, I don't see any reason to try to etch your own boards.
     
  15. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I recently had made some PCB's from a house in China, 10 boards, 10x10mm, double sided with solder mask, silk screen 1 side, plated thru holes.

    Total was $22.39 USD. That includes shipping. Took just under a month to get to my door. Faster shipping was an option (DHL is about $20 additional) but I made the order well in advance of need.
     
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