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Soldering SX48 SMT — Parallax Forums

Soldering SX48 SMT

william chanwilliam chan Posts: 1,326
edited 2006-01-10 18:47 in General Discussion
Mr Bean,

I have good news for you.
Just now I successfully soldered 3 SX48s using solder paste injector and a conventional oven.

Here's how I got it after a few tries.

1. Inject a thin line of solder paste on top of each row of pads.
2. Use a small cut out sponge to spread the paste thinly over the pads. Make sure they are really thin. Remove excess with tissue.
3. Place and align the SX48 using a magnifying glass with light.
If the solder paste is thin enough, you should still be able to see about 50% of the pads. This will help you align. I also use longer pads.
4. Put a small length of solder on the board near the SX48, and place the board into the pre-heated oven set at 250 degree celsius.
5. When you notice the solder length melt into a ball, get ready. Give it another 10 seconds, then remove the board slowly by pliers.

If the solder paste is thin enough, it usually will not bridge. I didn't use any flux.
Of course the board should have solder mask to reduce the chances of a bridge.

Good luck.

Comments

  • BeanBean Posts: 8,129
    edited 2006-01-06 14:04
    William,
    Thanks I will give that try sometime.

    I'm interested how is everyone else mounting the SX48 ?
    Bean.

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  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-01-06 15:13
    Tacking two opposite corners with low temp solder and flux, fluxing all pins, wave solder each line without touching actual pins (pad only to deposit solder), go back over with dry tip along pin->pad joint. Works very well, vitually no bridging (any bridging that occurs in first pass rectifies itself in second pass if proper amount of solder is used), most bridging occurs when you hop up onto the pins only. Whole process takes about a minute.

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    ·1+1=10

    Post Edited (Paul Baker) : 1/6/2006 3:16:48 PM GMT
  • GresethrGresethr Posts: 2
    edited 2006-01-06 16:54
    Guess I am an old fart, I still do it by hand.yeah.gif
  • John R.John R. Posts: 1,376
    edited 2006-01-06 17:11
    Paul;
    When you say "Wave Solder", are you talking the commercial production board lines, or some type of "prototype" process.· I'm a hobbyist, familar with the production assembly line/wave machines.· Is there a wave soldering availalbe for small runs?
    Paul Baker said...
    Tacking two opposite corners with low temp solder and flux, fluxing all pins, wave solder each line without touching actual pins (pad only to deposit solder), go back over with dry tip along pin->pad joint. Works very well, vitually no bridging (any bridging that occurs in first pass rectifies itself in second pass if proper amount of solder is used), most bridging occurs when you hop up onto the pins only. Whole process takes about a minute.

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    John R.

    8 + 8 = 10
  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2006-01-06 17:43
    Drag Solder with magnification for guidance [noparse]:)[/noparse] "Hoof" type tips on a good iron with liberal amounts of flux.


    Ryan

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    Ryan Clarke
    Parallax Tech Support

    RClarke@Parallax.com
  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-01-06 17:45
    sorry, wave soldering=drag soldering, I use a 0.6mm hoof type tip (xytronics calls it a wave tip), all done by hand. Commercial production runs are too expensive for lots <100.

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    ·1+1=10
  • ChrisPChrisP Posts: 136
    edited 2006-01-08 01:18
    Essentialy the same process Bill described, except with a chisel point tip. Tack two corners for alignment, flux all pins lightly <with liquid AR flux now> and drag a solder ball across. The flux really keeps the bridging down.
  • geekythinggeekything Posts: 53
    edited 2006-01-08 19:56
    I'm glad this thread popped up as I'm going to be soldering the SX48 by hand shortly!

    I can do SOICs in my sleep, but was actually a little worried about the '48s pitch.

    I'm also planning on trying the electric frying pan reflow (heard it's a bit easier/more controllable than the toaster oven).

    -marc
  • ElectronegativityElectronegativity Posts: 311
    edited 2006-01-09 23:32
    Hi.

    I haven't tried the SX48 yet, but I managed to solder and SX28SS by tacking one corner, aligning the rest of the pins with the point of an xacto knife, then putting the tiniest drop of solder on the end of an iron and pushing it down the traces towards the pins. I do 2 pins at a time this way, and got really nice little slopes of solder running from the pins to the traces.

    Whatever method you use, remember that flux is your friend.

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    I wonder if this wire is hot...
  • geekythinggeekything Posts: 53
    edited 2006-01-10 01:35
    Eectronegativity: ummm....no. Flux is *not* your friend -- that's the first thing you need to remember! Flux cleaner is your friend, though wink.gif

    -marc
  • Ryan ClarkeRyan Clarke Posts: 738
    edited 2006-01-10 15:22
    Flux is most definately your friend in certain circumstances. Organic when you can use it (needing cleaning) - and no-clean when you must.

    Flux will help remove those pesky solder bridges on the last legs of a row on a quad flat pack -

    Ryan

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    Ryan Clarke
    Parallax Tech Support

    RClarke@Parallax.com
  • Paul BakerPaul Baker Posts: 6,351
    edited 2006-01-10 15:28
    No-clean flux + alchohol to remove the tacky residue if it bothers you. If you are doing fine pitch work by hand flux is pretty much a nessesity, I wouldn't even think of attempting soldering an SX48 without it. Remember that you were dually warned when you are staring at a dozen bridges from trying to do it without flux.

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    ·1+1=10
  • ElectronegativityElectronegativity Posts: 311
    edited 2006-01-10 18:47
    On this note, I have been using a tin of plumbing flux that was leftover from soldering copper pipes.

    Does it matter?

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    I wonder if this wire is hot...
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