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Background: I just began with electronics and I'm looking to build a 12v to 5v converter circuit. My plan is to use a Murata 78SR-5 to power either an Arduino or Rasberry Pi. I'm studying electronic design on my own as a hobby so I may not have adequate circuit design as of yet, but I have noticed that there are few available for purchase capacitors with leads|pins on them which can be used on solderless breadboards. I can't find a capacitor with the specific voltage range with leads already existing for use with solderless breadboard prototyping so I turn to SMD/SMT type.

Question: What details are needed to know, if soldering leads/pins to SMD/SMT capacitors or resistors practiced? e.g. temp, wire size, wire alloy, etc.

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    \$\begingroup\$ This doesn't answer your question, but in case you don't know, the voltage rating on a capacitor doesn't need to match what your using, it just needs to be greater than it. That being said, you shouldn't have a problem finding through hole capacitors of most any size. Also soldering a wire to a smd package may be hard and at some point will probably break off. \$\endgroup\$ – Garrett Fogerlie Nov 27 '12 at 9:30
  • \$\begingroup\$ Through hole caps are more diverse than SMD ones (because they can get big). Also, I highly recommend getting a solderless breadboard (google it). They cost around $15 and will save you countless thrown away soldered boards. \$\endgroup\$ – Vorac Nov 27 '12 at 15:31
  • \$\begingroup\$ And if you don't break off the wire, you'll probably break off the component lead - those things are not durable at all. \$\endgroup\$ – W5VO Nov 27 '12 at 19:27
  • \$\begingroup\$ @GarrettFogerlie I found voltage needs to be higher shortly after posting. I wish I knew that sooner. \$\endgroup\$ – Sn3akyP3t3 Nov 29 '12 at 7:31
  • \$\begingroup\$ @Vorac Yes, I'm sorry if I wasn't clear. I meant solderless breadboards. I wasn't aware that term applied to solderless and soldered. I wish I knew someone in my area that did this for a hobby so I could pick up on the easy stuff without stumbling through it like this. I'll correct my question above. \$\endgroup\$ – Sn3akyP3t3 Nov 29 '12 at 7:34
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When you say bread board, I'm assuming you mean solderless bread boards.

Soldering legs to individual SMD caps will be fairly difficult, and likely fragile. You should be able to buy through-hole caps that have sufficient voltage at RadioShack, or at just about any online electronics distributor (digikey, mouser, etc). Here is an example of a 50V through hole capacitor.

When I want to use SMD components on a breadboard, I usually attach them to a breakout board first, and then run wires or header pins from the breakout board. Bellin makes many different snap-out breakout boards like this. It's a little on the pricey side, though. You could make your own by cutting up some solder-type bread boards. SchmartBoard is another brand of adapters you could check out.

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  • \$\begingroup\$ Yes, solderless breadboards. I didn't think about breakout boards instead of pins. I'll see if I can adopt some practice in that direction. \$\endgroup\$ – Sn3akyP3t3 Nov 29 '12 at 7:23
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A better solution may be breakout boards also called Surfboards (get it, breakout boards for surf-ace mount) from Capital Advanced, Digi-Key, and others. The 6000 series is for discretes, and the 9000 series for ICs.

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SMD resistors and capacitors (if you're talking about ceramic) are much more tolerant to temperature than SMD semiconductors; I was never able to damage any, and sometimes I'm pretty abusive; semis, on the other hand, were an easier task to fry...

Anyway, don't try to solder them with solder wire; instead, buy some SMD solder paste, apply a small amount on the solder points with the tip of a wooden splurge (that's what works best for me), place the resistor/capacitor over it with a tweezer and use a hot air rework tool to heat it and melt the solder. Or, if you don't have a HART, use the soldering iron tip to heat the board copper of one of the contacts until the solder melts, wait a few seconds and do the same to the other contact. This will take 2-3 seconds, which is tipically safe even for diodes. In both cases, use the lowest temperature that can still melt quickly the solder. For leaded solder, I use 390F, for lead-free 420F. Even with a soldering iron, it is essential to have a temperature-controlled one.

Finally, the smallest SMD parts I use are 0805; smaller ones are too hard to do a quick&clean job, at least in my case (obviously this may be different for you if your handling skills are better than mine).

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  • \$\begingroup\$ Wire solder will be just fine. Paste is hardly needed for hand soldering, has a limited shelf life, and is extremely messy. If one were doing something like a QFN it might be a different story, but not for leaded ICs or chip resistors/capacitors. \$\endgroup\$ – Chris Stratton Nov 27 '12 at 18:05
  • \$\begingroup\$ Well, that may be a matter of personal preference. I'd go for this method youtube.com/watch?v=IgrEbJN8dcQ&feature=related because in my case it's faster and produces better results. \$\endgroup\$ – fceconel Nov 27 '12 at 18:36
  • \$\begingroup\$ The speed and quality are primarily driven by experience. What is fundamentally different is that to use your method one needs special equipment and supplies with a short shelf life - yet you can easily do a good job with a readily available iron and wire solder. Paste is primarily a production-scale tool, and for things like multi-pin leadless packages such as QFN's that are hard to do with wire solder. \$\endgroup\$ – Chris Stratton Nov 27 '12 at 20:08
  • \$\begingroup\$ Yes, the paste has a limited lifespan and has to be kept refrigerated, but these limitations are mainly to preserve its homogeneity when applied with a stencil for consistent results in such situation. If you use it like I mentioned, applying small drops with a tip, you don't have to worry so much. I have a paste syringe here that was bought two years ago and that I use regularly. As for the special equipment, agreed, the ideal is to have a hot air tool. But a soldering iron also works, and in any case (even with wire solder) it is highly recommended to be temp controlled. \$\endgroup\$ – fceconel Nov 27 '12 at 21:27
  • \$\begingroup\$ Temp controlled irons are nice, and quite worth their inexpensive current prices, but again not something that is needed for making a couple of joints on 2-contact parts. Assuming the operator isn't holding the iron on the joint longer than is needed, the main thing which the temperature control protects is the lifetime of the iron tip plating. It also allows having a more powerful heating element for faster warmup and easier soldering of thermally massive joints, but neither is likely critical here. \$\endgroup\$ – Chris Stratton Nov 27 '12 at 21:36

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