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SMD/SMT Ideas, Kits, Experience...?

Discussion in 'General Electronics Discussion' started by Number, Jun 19, 2013.

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  1. Number

    Number

    65
    0
    Jun 9, 2013
    I've really taken to giving SMD components a shot, and I am wondering if any of you members out there have any tips, such as what's the smallest component size you've used? I do not think I'll try anything below the 1608 because at that point the size of the package is so small you need tweezers & steady hands. The tweezers I have. The hands? Not so much.

    Does anyone have any recommended starter kits? I know they aren't too expensive since Jameco lists some parts as 0.0099 cents. Not even 1% of 1 penny it costs to make some of them. Plus I like how you can get them in the thousands and maybe take up a one liter bottle of space. That's awesome since I don't have much workspace. How would you recommend storing them? I saw some binders for sale, which I don't think I would use or buy. I just storing them in say, a mason jar work? I'm thinking about mass storage and ease of access as well. So can they easy be grabbed, picked up, whatever?

    Thanks for any help. :cool:
     
  2. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
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    Jan 21, 2010
    I've manually soldered 0603 and I have repaired a device containing 0402 (where one end of a resistor had been pulled from the board -- don't ask...)

    1206 are big and easy, 0805 are relatively easy.

    .127 pitch ICs, are a doddle with the right technique.

    Billions would be a litre. Early on I purchased a set of 5000 x 0805 resistors in various values 1R to 10M and they came in a small envelope.

    get yourself some curved tweezers so you can rest your hand on the bench and hold the resistor at the same time. Something like this (although mine are just plain metal).

    I keep the components how I receive them :) If on reels, they stay on reels, if in little plastic bags, they stay in little plastic bags.

    The only exception is if they come on short strips. These get placed into small bags (the strips, I don't remove them from the packaging).

    All the bags, reels, etc are numbered and placed in appropriate boxes. I keep an index of what number each component is and which box it is in.

    As a warning, some components can be really hard to identify (surface mount ceramic capacitors have no makings in many cases) so it's well worth keeping things well labelled as well.

    I purchased some ceramic capacitors early on and they came in small boxes like these. They are handy, but I didn't go that way for any other components. A more upmarket version is here.

    In the end, the actual storage will matter less than your ability to find them again!

    Note that some surface mount components have a lifetime that they can be stored unsealed, however this is more of a concern for automated manufacture than for hand assembly.
     
  3. Number

    Number

    65
    0
    Jun 9, 2013
    Did you use a heat gun or a soldering iron? I also heard about "Soldering Pots" but I'm not to familiar with them.

    EDIT:
    One thing that I failed to consider was prototyping/breadboarding them. Solutions I came across were adapters for ICs and using Schmartboard. This did not seem like breadboarding or prototyping, more like using extra tools. I'm sure that it is near to impossible to do this, because in the end it appears like something always requires soldering. My initial thought was using a large rectangular perfboard that has the individual pads as opossed to stripboards. What has your experience been with regards to this?

    This is what I had in mind, I'm glad someone did it already.

    [​IMG]

    Found it here...
    Link
     
    Last edited: Jun 19, 2013
  4. eKretz

    eKretz

    251
    26
    Apr 8, 2013
    I have done a fair amount of SMD work recently, I prefer using a soldering iron for most build or repair work where I'm only doing a fairly small number of joints. If it was a new kit with many parts, I would probably use reflow with a solder mask instead just to save my back (got a bad one, and bending over the desk/bench for much more than 20-30 minutes puts a serious hurt on me) and a whole lot of time. Here is a link to some good how-to vids for SMD soldering with an iron:

    http://www.youtube.com/user/SolderingGeek/videos?flow=grid&view=0&sort=da

    I use the same techniques as this guy and it works great.
     
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
    2,731
    Jan 21, 2010
    For resistors and capacitors, just use leaded components. If you have any components you use regularly, get leaded ones as well. You can also get breakout boards for components not available in leaded form.

    Here is an example of something I use fairly regularly. And these too.
     
  6. shrtrnd

    shrtrnd

    3,701
    462
    Jan 15, 2010
    My input echoes *steve*s.
    I keep the SMD parts in WELL-LABELLED small plastic bags (or ESD bags for semiconductors).
    It is an unbelieveable pain, to have a cluster of unmarked SMD parts, and then try to
    re-identify them.
     
  7. Number

    Number

    65
    0
    Jun 9, 2013
    Thanks for the input guys, a lot of good info you posted. I think what I'll do is combine the breakout boards for ICs and use the male headers for caps, resistors etc. I figure if I have a couple hundred or a thousand I'll make about 3-5 "breadboard" compatible. So I can breadboard/prototype then go straight to the PCB once I've done a test run.

    Have any of you used a tweezer tip for the soldering iron? I don't know how you would 'tweeze' a piece because the tip is hot, but I did see some online & at my local electronics store/warehouse. I thought it was interesting but not very practical.
     
  8. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
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    Jan 21, 2010
    They're really useful for quickly removing parts, not so much for soldering them.

    To solder a surface mount resistor (say) there are several techniques:

    1) place the component down with the tweezers and use the tip of the tweezers to hold the resistor in place. Now with your other hand pick up the soldering iron, whilst your third hand gets the solder and you solder the device almost like anything else. This is trivially easy and applicable to all components. It only works well if you have 3 arms (or perhaps a soldering iron which dispenses solder).

    2) Tin one of the pads (only one!). Place the component with the tweezers and hold in place. Use the soldering iron to melt the solder whilst you allow the component to settle on the pad. with one end tacked in place solder the other end, then return and solder the first end properly. This is generally the technique I use. It works for anything up to 100 pin 0.5mm pitch chips (the largest I've hand soldered). The important thing is to get the alignment right when you tack the first connection. For devices having many leads, I typically solder an opposite corner next, then return to the original pin, then start on the others. (for very fine pitch devices there are tricks which allow you to use relatively large soldering iron tips)

    3) Use a mechanical device (or even glue) to hold the component in place before soldering all the leads. This has the advantage of getting the alignment right to start off with, but it is generally pretty time consuming.

    4) place a smear of solder paste on the pads, drop the component on it. (sometimes it can pay to hold the component in place with the point of your tweezers -- better though to avoid this) Then use a hot air gun to reflow the solder. In most cases, surface tension will pull the component into alignment. However if you're not careful you can blow the component away or disturb nearby components (generally through the use of too vigorous an air stream).

    5) place lots of components on the board (as above) then place them in a reflow oven.
     
  9. Number

    Number

    65
    0
    Jun 9, 2013
    I'd never thought of using an oven for soldering purposes. I'll definitely give that a go at some point. :cool: Perhaps a toaster oven might work as well? Although I don't think there would be as much control over the temperature when compared to the oven.
     
  10. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

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    Jan 21, 2010
    Yes, people use all sorts of things from frying pans to real reflow ovens. Toaster ovens are in the middle somewhere.

    Just make sure it can get up to soldering temperature within about 5 minutes and DONT use it for food afterwards!
     
  11. CluQu

    CluQu

    14
    0
    May 22, 2013
    Somehow I don't see PCB Toast tasting that well. Needs more silicon. :eek:
     
  12. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
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    Jan 21, 2010
    And far less lead (flux aint that good for you either).
     
  13. Number

    Number

    65
    0
    Jun 9, 2013
    Maybe that explains some things...:eek:

    Where do you recommend I buy the SMD parts from? You mentioned you had a resistor package from 1 Ohm to 1 Megaohm (or Megohm, idk which is technically correct). Today I went to the local electronic warehouse to get some SMD parts & the only thing they had was ridiculously small resistors & capacitors. So I'm still in search of some relatively cheap, large sized SMD parts. :rolleyes:
     
  14. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
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    Jan 21, 2010
    It depends what you want to do.

    How good are you at producing PCBs? (Because you're not going to have an option to use matrix board or veroboard much any more).

    You can get lots of components from places like Mouser, RS, Digikey, etc.

    For experimenting, or where quality isn't critical (or even important), there's also ebay.

    Just like you can get packs of assorted through-hole resistors and capacitors, you can also get the same for SMD components.
     
  15. Number

    Number

    65
    0
    Jun 9, 2013
    So I just got 140 Misc. LEDs, 200 Misc. Transistors, and 2140 Misc. Resistors & Capacitors. I think I'm good for now. And all for $28 including the shipping. No sales tax, as I live in the worst state of them all, Oregon.

    So did I get jewed or is that a reasonable deal?


    EDIT:
    I just got some Tweezers. They seem legit & fit what you recommended earlier.
     
    Last edited: Jun 20, 2013
  16. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    25,293
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    Jan 21, 2010
    Seems a reasonable deal. Now you've got to build stuff :D

    I think you'll find the curved tweezers very useful. The straight ones are probably better for picking things out of packets though.
     
  17. BobK

    BobK

    7,673
    1,684
    Jan 5, 2010
    I have not tried it, but I read an article about using an electric fry pan for reflow and, according to the author it worked better than any oven he had tried. I would like to try this one some time.

    Bob
     
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