DIY SMT??

[Michael P.]

Is it possible to employ surface mount technology at home with no special equipment for relatively low cost? I'm asking because there are a couple of EQ circuits that I'd like to install directly in my Strat, where space is at a premium.

[javacody]

Michael, there is a thread here somewhere about a guy who makes robot boards using smt components, a special solder paste, and a toaster oven. I would think that it would be possible, and probably not too hard, once you got the hang of it. I've been thinking of making tiny Fuzz Face circuits, myself. What would be cool would be a tiny fuzz face, a tiny Treble Booster, and a tiny mini booster all in the same box.

[Peter Snowberg]

I think it's actually easier to work with SMT than through hole parts in most cases.

All you need is a fine tip on a temperature controlled solder station ($40), some flux paste (available at RadioShack), and fine solder.

To solder a resistor, just apply a little flux paste with a Q-tip, melt a tiny bit of solder on one of the pads, hold the resistor in place, touch the iron to the pad to re-flow the solder, solder the other side, finished.

If you get ready made PCBs with solder coating, often you don't need any additional solder. Just add some flux paste and re-flow the solder already on the surface.

I can solder SOIC packaged chips in a fraction of the time it takes to do DIPs. Just add flux paste to the board, align pin 1, solder that pin, align the pin on the opposite corner, solder that one, now touch the iron to each of the remaining pins for a fraction of a second each.

[Michael P.]

Wow! Thanks, I didn't think this was at all reasonable. Basically, I want to incorporate circuits like the Red Ranger and the Purple Peaker as alternatives to buying EMG EQ components, and this may make it possible.  

Peter, can I get by with a regular soldering iron? It's fairly low wattage. And what do you use to hold the component - needle nosed pliers, perhaps?

[O]

Here you go... it opens up some cool possibilities if it actually works...

El Linko

[MR COFFEE]

Michael,

You can get by with a cheaper iron if you

1) Put a diode in series with the line cord to tame the temperature if it gets too hot

2) Use a file to reduce the amount of thermal mass (i.e., metal) in the tip that will be in close proximity to the tip. Said another way, make the end of the tip into a narrow cylinder fro the last 3/8" or so - maybe 1/16" in diameter. This keeps the iron from dumping too much heat into the joint too fast so the flux and/or your component goes bad before everything is whetted and the joint is soldered.

3) Hold the components still with "Tack" adhesive, that stuff they sell for holding posters on the wall that never hardens, while you solder the other end, or tack down opposite corners as described above. And take it off afterwards (I fear someone will otherwise leave it on if I don't say so)  :lol:

4) Get some liquid flux and use it. Tin the board before you put ANY components on it if it doesn't come from a supplier already tinned (like if this is real DIY and you make the board).

5) Work under a BRIGHT light, and maybe use a magnifier if you can't see any better than I can. SMT is really small.

Practice, and use small guage solder. A little silver in the solder alloy reduces leaching the silvered contacts on many SMT components. Not required, however.

[Paul Perry (Frostwave)]

I remember seeing somewhere a guy converted a 'big clunker' iron to a 'tiny' iron by getting some thinck copper wire , winding a tight spiral of it around the clunker's tip, and then bending the end of the wire straight & shapint the end to a mini bit.
Would I do it? No.
Does it work? Can't see why not!