How to solder electronic components?
May 31, 2010 3:19 PM Subscribe
I'm trying to pick up this Arduino project, but I do not know how to solder. I bought this temperature controlled Weller unit, and leaded solder (63% Sn / 37% Pb). What temperature do I need set the unit to? How exactly does "tinning" work? How do I prevent the board from burning when the tip gets close?
I believe I can solder two wires together, but they're big and easy. In small spaces, I'm having trouble with things that look like this. I assume that soldering just takes practice, as everyone seems to regard it as an easy thing to do. I picked up a couple of learning electronic kits from SparkFun (metrognome, simon says game), and I've got none of them to work. Is there any way to test the individual joints and see which ones I did right and which ones I did wrong?
I believe I can solder two wires together, but they're big and easy. In small spaces, I'm having trouble with things that look like this. I assume that soldering just takes practice, as everyone seems to regard it as an easy thing to do. I picked up a couple of learning electronic kits from SparkFun (metrognome, simon says game), and I've got none of them to work. Is there any way to test the individual joints and see which ones I did right and which ones I did wrong?
You shouldn't need to tin anything for something like those Sparkfun kits. The pads on the board are pre-tinned. As someone who rarely solders, I find that it takes me an hour or so to get my technique back (usually just as the project is finishing up.)
If you have a multimeter (you should) you can measure for continuity to try and determine which joints might be bad.
posted by ecurtz at 3:46 PM on May 31, 2010
If you have a multimeter (you should) you can measure for continuity to try and determine which joints might be bad.
posted by ecurtz at 3:46 PM on May 31, 2010
Basic but necessary tip: make sure that your soldering tip is clean. A dirty tip will mean that the solder will just stick to your soldering iron; on a clean tip, the solder will flow nice and easy onto the board. Get a wet/damp paper towel or a sponge and clean the tip on this periodically, and that'll make everything so much more easier!
posted by suedehead at 3:51 PM on May 31, 2010
posted by suedehead at 3:51 PM on May 31, 2010
What temperature do I need set the unit to?
My soldering iron is currently set to 350 degrees centigrade.
In small spaces, I'm having trouble with things that look like this.
Do you mean the pins on the bottom which are 0.1" apart, or do you mean the smaller components on top? Those smaller components are called surface mount components; you'll need more soldering experience before attempting that.
I assume that soldering just takes practice, as everyone seems to regard it as an easy thing to do.
Half of soldering is practice, half is recognising and avoiding things that are difficult to solder :)
I picked up a couple of learning electronic kits from SparkFun (metrognome, simon says game), and I've got none of them to work. Is there any way to test the individual joints and see which ones I did right and which ones I did wrong?
Once you know what to look for, you can just look at the joint with a magnifying glass. Knowing what to look for, that's the hard bit :)
One option would be to see if any of your friends have soldering experience, or join a local hobby organisation (I gather a lot of places have robot-building clubs and things these days); tutorials like roerek linked to explain things as best they can, but it's just simpler to instruct these things in person!
posted by Mike1024 at 4:03 PM on May 31, 2010
My soldering iron is currently set to 350 degrees centigrade.
In small spaces, I'm having trouble with things that look like this.
Do you mean the pins on the bottom which are 0.1" apart, or do you mean the smaller components on top? Those smaller components are called surface mount components; you'll need more soldering experience before attempting that.
I assume that soldering just takes practice, as everyone seems to regard it as an easy thing to do.
Half of soldering is practice, half is recognising and avoiding things that are difficult to solder :)
I picked up a couple of learning electronic kits from SparkFun (metrognome, simon says game), and I've got none of them to work. Is there any way to test the individual joints and see which ones I did right and which ones I did wrong?
Once you know what to look for, you can just look at the joint with a magnifying glass. Knowing what to look for, that's the hard bit :)
One option would be to see if any of your friends have soldering experience, or join a local hobby organisation (I gather a lot of places have robot-building clubs and things these days); tutorials like roerek linked to explain things as best they can, but it's just simpler to instruct these things in person!
posted by Mike1024 at 4:03 PM on May 31, 2010
Response by poster: Ah, so you don't want solder on the tip to begin with? I was perhaps misunderstanding the idea behind tinning. It sounds like I need to touch the through wire and the pad itself to the ironing tip then add a bit of solder to help the process along and then pull out?
posted by geoff. at 4:10 PM on May 31, 2010
posted by geoff. at 4:10 PM on May 31, 2010
I found this tutorial to be very helpful while learning to solder. Soldering is easy, but it takes a few hours to become comfortable with how melted solder behaves, how to manage holding the iron, component and board steady, how to not inhale a huge amount of fumes, etc. I would go back to the kits you have and try to fix them (good practice for de-soldering! I like to use copper braid for this). This will also teach you how to use a multimeter which you absolutely should become familiar with if you are about to attempt any kind of circuit building stuff.
Are you trying to build your own Arduino from a kit of loose components? Things that lay on top of boards instead of sticking their little legs through the holes are called surface-mount or SMD---you need special tools and more know-how to deal with those. If you've got one of those, I might step back for a bit and order one of the more comprehensive Arduino kits. Adafruit has a few reasonably priced kits.
posted by supernaturelle at 4:18 PM on May 31, 2010
Are you trying to build your own Arduino from a kit of loose components? Things that lay on top of boards instead of sticking their little legs through the holes are called surface-mount or SMD---you need special tools and more know-how to deal with those. If you've got one of those, I might step back for a bit and order one of the more comprehensive Arduino kits. Adafruit has a few reasonably priced kits.
posted by supernaturelle at 4:18 PM on May 31, 2010
make sure that your soldering tip is clean
This is important. More specifically, a tip that has been hot for quite a while (say, more than 10 minutes) without being cleaned will start to form some kind of oxide layer, with the result being that any solder you try to melt just keeps going into a bigger and bigger ball at the end of the hot tip, but nothing ever flows onto the work. You know you are doing it right when you touch the solder to the work (not to the tip of the iron) and it flows instantly.
A properly cleaned iron ready for work should be very shiny (no darkish bits or blackish specs) and should have all excess solder flicked off -- there shouldn't be anything bubbly-looking at all anywhere.
Also, you are using rosin core solder right?
posted by Rhomboid at 4:18 PM on May 31, 2010
This is important. More specifically, a tip that has been hot for quite a while (say, more than 10 minutes) without being cleaned will start to form some kind of oxide layer, with the result being that any solder you try to melt just keeps going into a bigger and bigger ball at the end of the hot tip, but nothing ever flows onto the work. You know you are doing it right when you touch the solder to the work (not to the tip of the iron) and it flows instantly.
A properly cleaned iron ready for work should be very shiny (no darkish bits or blackish specs) and should have all excess solder flicked off -- there shouldn't be anything bubbly-looking at all anywhere.
Also, you are using rosin core solder right?
posted by Rhomboid at 4:18 PM on May 31, 2010
Also, I've always been under the impression that you do tin the tip of the iron. It helps keep the tip in better shape as well as allowing heat to transfer easily between the iron and component parts.
posted by supernaturelle at 4:22 PM on May 31, 2010
posted by supernaturelle at 4:22 PM on May 31, 2010
you don't want solder on the tip to begin with?
The tip should always have some solder but the lightest of coatings -- give it a few good hard flicks and then a wipe on a wet sponge and you should be ready to go. Ideally you should never touch the tip of the solder to the tip of the iron, ever -- the iron heats the work and then the solder touches the work. But sometimes you have to sort of compromise and touch the solder to both the tip and the work at the same time if it won't start or you don't have room.
Regarding tinning, the idea is that if you're trying to attach a bare copper wire to something it's easier if the end of the wire already has some solder on it, so before ever putting the wire near the circuit you heat it and melt some solder on it -- just enough to make it silvery instead of coppery. Then you put that in the hole and heat up both the wire and the hole again and put a dab more solder on both. The tinned wire helps heat transfer and ensures that the solder wets everything.
posted by Rhomboid at 4:28 PM on May 31, 2010
The tip should always have some solder but the lightest of coatings -- give it a few good hard flicks and then a wipe on a wet sponge and you should be ready to go. Ideally you should never touch the tip of the solder to the tip of the iron, ever -- the iron heats the work and then the solder touches the work. But sometimes you have to sort of compromise and touch the solder to both the tip and the work at the same time if it won't start or you don't have room.
Regarding tinning, the idea is that if you're trying to attach a bare copper wire to something it's easier if the end of the wire already has some solder on it, so before ever putting the wire near the circuit you heat it and melt some solder on it -- just enough to make it silvery instead of coppery. Then you put that in the hole and heat up both the wire and the hole again and put a dab more solder on both. The tinned wire helps heat transfer and ensures that the solder wets everything.
posted by Rhomboid at 4:28 PM on May 31, 2010
There are tutorials on the Lada Ada website meant for beginning solderers, complete with video.
posted by phearlez at 5:31 PM on May 31, 2010
posted by phearlez at 5:31 PM on May 31, 2010
You want enough solder on the tip of the iron that it'll conduct heat well to the thing you're soldering, but not more than that (specifically, the idea is not to have a blob of solder on the iron that you transfer to the joint). The way it should work is: the iron touches the joint, it heats the joint up, the solder touches the joint (elsewhere!), and when the joint is hot enough the solder will melt and flow around the joint. Then remove the iron & solder and it'll cool. The reason for all this is that if the metal you're soldering is too cold, you'll get a "cold" solder joint, where the solder doesn't really wet the surface of the metal. By melting the solder with the joint, instead of directly with the iron, you know that the joint is hot enough when the solder flows onto it. (Probably also helps the flux work. Also, molten metal tends to flow towards the heat, which means it's hard to get it to flow off the iron onto anything else.) Cold joints are both electrically and mechanically weak. They're not hard to see by inspection, once you have an idea what they look like.
Every now and then, melt a small blob of solder directly onto the tip of the iron and wipe it off (on a sponge, eg) or flick it off (careful with the flying blobs of molten metal though). This gets rid of the oxide that's forming on the always-hot iron.
Often you'll find yourself cheating a little, gooping a slight amount of solder directly onto the iron's tip, or touching the solder simultaneously to the joint and to the iron, or whatever. This is fine, just keep an eye out for cold joints or solder bridges. You can always just re-melt the joint to fix it.
Never file, grind, or otherwise abrade the tip of the iron. All but the cheapest tips are copper-with-iron-plating. If you file off the iron plating, your solder will reach the copper and slowly dissolve it as you use the iron. (Cheap tips skip the iron plating and are just copper, and they don't last very long.)
Printed circuit boards and most component leads are pre-tinned. Copper wire might need to be tinned especially if it's kind of oxidized and dull.
posted by hattifattener at 9:09 PM on May 31, 2010
Every now and then, melt a small blob of solder directly onto the tip of the iron and wipe it off (on a sponge, eg) or flick it off (careful with the flying blobs of molten metal though). This gets rid of the oxide that's forming on the always-hot iron.
Often you'll find yourself cheating a little, gooping a slight amount of solder directly onto the iron's tip, or touching the solder simultaneously to the joint and to the iron, or whatever. This is fine, just keep an eye out for cold joints or solder bridges. You can always just re-melt the joint to fix it.
Never file, grind, or otherwise abrade the tip of the iron. All but the cheapest tips are copper-with-iron-plating. If you file off the iron plating, your solder will reach the copper and slowly dissolve it as you use the iron. (Cheap tips skip the iron plating and are just copper, and they don't last very long.)
Printed circuit boards and most component leads are pre-tinned. Copper wire might need to be tinned especially if it's kind of oxidized and dull.
posted by hattifattener at 9:09 PM on May 31, 2010
Another thing to try if you're still struggling is to switch to a chisel tip. Those Wellers come with those tiny little pencil tips which might be good for precision work but they're not the best for learning because they don't present a lot of surface area. A chisel tip may be a little clumsier in tight spaces but it gives you nice flat surfaces that really get the work up to temperature fast. For everything but surface-mount I do better work with a 20 year old unregulated $5 rat shack iron with a chisel tip than a fancy temperature controlled Weller with a cone tip.
posted by Rhomboid at 10:08 PM on May 31, 2010
posted by Rhomboid at 10:08 PM on May 31, 2010
The curiousinventor tutorials that supernaturelle linked to are really good – IIRC their surface-mount soldering methods are easy and work. This is their surface-mount soldering tutorial video – check it out by all means.
DIY audio guru Tangent at tangentsoft.net also has some great stuff; Here are his tutorial videos – Tangent Tutorials. Here's his "Getting Started in Audio DIY" page, which tells you about tools and first techniques. (Basic Audio DIY and basic Arduino work is about the same, tools-wise.)
Question for OP: Is my understanding correct that you're mostly having trouble with surface-mount components? If that is the case, then BUY SOME LIQUID SOLDER FLUX NOW (cf. Tangent / Curiousinventor tutorials.) Liquid solder flux is the magic sauce that makes surface-mount soldering easy.
Contrary to what everybody thinks at first, surface-mount soldering is not about eyesight or hand-eye coordination or dexterity at all. Nor tools. If you have a decently fine tip on your iron, and decent leaded solder, and some liquid flux, then that's it - you have all you need. The only thing which the solderer must contribute is an intuitive feel for how solder behaves. How the solder flows as it melts and freezes again. How the heat from the iron flows through the solder and surrounding metal.
Obtaining this intuition is not hard at all. We have the internet. Just watch some tutorial videos, and solder and desolder some practice joints.
posted by krilli at 2:07 AM on June 1, 2010 [1 favorite]
DIY audio guru Tangent at tangentsoft.net also has some great stuff; Here are his tutorial videos – Tangent Tutorials. Here's his "Getting Started in Audio DIY" page, which tells you about tools and first techniques. (Basic Audio DIY and basic Arduino work is about the same, tools-wise.)
Question for OP: Is my understanding correct that you're mostly having trouble with surface-mount components? If that is the case, then BUY SOME LIQUID SOLDER FLUX NOW (cf. Tangent / Curiousinventor tutorials.) Liquid solder flux is the magic sauce that makes surface-mount soldering easy.
Contrary to what everybody thinks at first, surface-mount soldering is not about eyesight or hand-eye coordination or dexterity at all. Nor tools. If you have a decently fine tip on your iron, and decent leaded solder, and some liquid flux, then that's it - you have all you need. The only thing which the solderer must contribute is an intuitive feel for how solder behaves. How the solder flows as it melts and freezes again. How the heat from the iron flows through the solder and surrounding metal.
Obtaining this intuition is not hard at all. We have the internet. Just watch some tutorial videos, and solder and desolder some practice joints.
posted by krilli at 2:07 AM on June 1, 2010 [1 favorite]
One more thing – try posting some pictures of your solder joints, as "macro" as you can make them. (Flatbed scanners are OK for this, good SLR with macro better, anything is enough.) Either post them here or on a helpful DIY electronics forum. Or both.
I predict you'll get some good hints pretty quickly, you'll need to make minor changes to your soldering style, and your joints will get MUCH better all of a sudden.
posted by krilli at 2:12 AM on June 1, 2010
I predict you'll get some good hints pretty quickly, you'll need to make minor changes to your soldering style, and your joints will get MUCH better all of a sudden.
posted by krilli at 2:12 AM on June 1, 2010
Arggh ... I borked my links. Too many words already, but since I'm at it the links have to be here:
Tangent's video tutorials.
Curiousinventor surface-mount soldering video.
posted by krilli at 2:14 AM on June 1, 2010
Tangent's video tutorials.
Curiousinventor surface-mount soldering video.
posted by krilli at 2:14 AM on June 1, 2010
Temperature: I can't afford fancy-schmancy controlled units, but leaded solder melts at 183°C. Set it a tad higher than that.
I think everything else has been well covered but you need a way higher temperature than just above the melting point of the solder. I typically run 350-400C. It may sound counterintuitive but too low of a temperature can actually be worse for heat sensitive components. If you have your iron too low it will take along time to heat the pin and pad hot enough to get the solder to flow, and the overall temperature of the component will get very high due to heat conductivity. But if you have the heat set high enough you'll be able to solder the connection very quickly before the component as a whole heats too much.
posted by 6550 at 9:53 AM on June 1, 2010
I think everything else has been well covered but you need a way higher temperature than just above the melting point of the solder. I typically run 350-400C. It may sound counterintuitive but too low of a temperature can actually be worse for heat sensitive components. If you have your iron too low it will take along time to heat the pin and pad hot enough to get the solder to flow, and the overall temperature of the component will get very high due to heat conductivity. But if you have the heat set high enough you'll be able to solder the connection very quickly before the component as a whole heats too much.
posted by 6550 at 9:53 AM on June 1, 2010
Response by poster: Thanks all! I finally figured it out, I'll post a write up soon in case someone is having the same problem and wants to hear from someone who just figured it out.
posted by geoff. at 1:51 PM on June 3, 2010
posted by geoff. at 1:51 PM on June 3, 2010
This thread is closed to new comments.
Tinning: you basically just cover the pads (or wires) with a thin layer of tin. Put the tip of the soldering iron on the pad to be tinned, wait a few seconds, and put some solder on it (not on the tip of the solder! preferably on the pad, but I normally let it touch the end of the tip _and_ the pad)
Temperature: I can't afford fancy-schmancy controlled units, but leaded solder melts at 183°C. Set it a tad higher than that.
Testing joints: the term you're looking for is "cold solder joint". Google images gives examples how it should not look. Or here: http://www.aaroncake.net/electronics/solder.htm Does your soldering look like this?
posted by roerek at 3:33 PM on May 31, 2010