Hello friends, Joe here from HackerBoxes. Today we're going to learn how to solder.
And we're going to learn to solder using this cool little kit, which we call a badge buddy.
It has some blinking LEDs and a battery and a switch. So not many components, it's pretty
easy to make. It's a nice first start if you haven't soldered before.
So first let's talk about what is soldering. So soldering is just melting solder, which
is an alloy, a metal alloy, that has a very low melting point. So we melt the solder using
a soldering iron, a tool like this, and we melt it between things that we want to connect
together, usually connecting them electrically, although we will discuss that there's more
to it than that. We see things that are soldered all the time and we have the entire world
around us is full of electronic gizmos that have components soldered onto circuit boards.
So it's a big part of our lives whether we stop and think about it or not. Being able
to solder is a really nice skill to have because you can repair things, modify things,
connect wires to things to read data in and out of them. It's a really excellent hacker
skill, a nice DIY skill. Once you get into it, you'll find that it comes in handy a lot
and it's one of these skills that you can kind of apply to a lot of different things.
Alright, I thought I would start by just saying, you know, kind of big picture, there's kind
of two things that we want to kind of keep in mind that are really important. The first
one is pretty obvious and it's almost sort of a joke. You've probably seen these pictures
online. This is a soldering iron. It's off, obviously. If it smells like chicken, you're
holding it wrong, okay? Always hold the rubber handle. So that's the first big picture item.
The next big picture item is to realize that you always need more solder. And I don't mean
by that that you need to go out and always buy some more solder because you need to have
lots of solder. But when you're working, soldering, working on some work that needs to be soldered,
you'll find initially that generally you need more solder than you think you need. And when
something isn't working right, you need to add more solder to it. And sometimes that's
counterintuitive, especially when we're trying to unsolder something. Adding more solder
is a vital part of unsoldering. So just keep those two things in mind. You know, the first
one's obvious. The second one can be a little counterintuitive. Smells like chicken, you're
doing it wrong. Number two, you probably always need more solder. Just don't be afraid to
add more solder. So solder serves three purposes. And I think this is one of these important
things because there's some subtle importance to these three different things. And they're
different and contained in the fact that these three things that solder does are separate
jobs of the solder. Contained in that are some of the common problems that people have
as they're getting into soldering. So the first one is almost obvious. It's that soldering
mechanically connects two things. So it's almost like glue. You're almost using it like
a hot glue. You melt it between two things and it connects them. You know, but is that
enough? Certainly not. Because really often the main point of the solder, aside just holding
two things together, is you have to have a good electrical connection. Something that
current will flow through. Not something that will easily break apart and not something
that actually has small gaps in it. So if you go at it thinking I just need to get these
two things stuck together like glue and you don't think about needing to have that really
nice electrical bond, you might be missing something. And the third thing, which is this
is the part that's a little subtle that often people miss in the very beginning. And usually
this is one of these things where when you get this, usually your soldering game goes
up to the next level. And that's that one of the jobs of the solder is actually a thermal
conduction. And what I mean by that is because there's two different ways that that's true.
But the one that's really important is that it is the solder that allows heat to flow
from the soldering iron onto the work. Okay, so if you don't have solder in the play before
you even start soldering, in other words, if your tip isn't tinned, if you don't have
the work, the pieces of work, meaning the wire and the pad or whatever it is you're
trying to solder together, you don't have solder in play, there won't be a thermal conduit
for heat to go from the tip of the soldering iron into the work, which is really what you
want to do as we'll discuss. So just remember that part of the job of the solder is to actually
be a thermal conductor. Okay, so it's a mechanical bond, it's an electrical conductor, but it's
also a thermal conductor. And the second way in which it's a thermal conductor is in some
instances where you have components that get warm while they're operating. So maybe let's
say a linear regulator or something. It being bonded with solder onto a PCB or some other
substrate can allow the thermal energy to flow out of it to keep it cool so it doesn't
overheat. So that's kind of a secondary way. But what I'm really talking about when I say
this subtle thing about thermal conduction is while you're soldering, you need the solder
to help do the soldering. It isn't just a glue, it's actually a conduit of the making
of the connection. So try to keep that in mind. So let's talk about some of the tools
and supplies that we use when we're soldering. The first obvious one is a soldering iron.
The really cool thing about soldering irons is in the last 15 years or so, the price profile
of soldering irons has changed quite a lot. Now for what would have been unheard of 20-30
years ago, you can get for a price that would have been unheard of, meaning even as little
as like $20, $30, $40, you can get a very nice soldering iron. I know the soldering
irons that I came up wishing that I could have had but I only had access to in a lab
because they were $250. Now we get soldering irons all the time that are in the $20 range
that are of similar quality. Controllable temperature and very nice tips that stay very
clean for a very long time. So that's a nice thing is soldering irons are readily available
now and they're not super expensive. I mean you can still spend a lot of money on a really
nice soldering iron but generally what you really want is just one that has a nice quality
tip that's replaceable. Although you'll find you might not actually need to replace it
very much if it's a nice tip. And you need to be able to adjust the temperature because
there are times when you want a little more heat on the tip or a little less heat. You
also just don't want it to just always be some preset random amount. So, you know, really
inexpensive soldering irons don't have a temperature adjustment. All right, another tool or part
of a tool you'll need is you'll need to always be able to clean the tip of your soldering
iron. You basically have to keep it clean all the time. If you're thinking always clean
the tip or constantly clean the tip, you'll end up cleaning it a lot which is what you
really need. You need to clean that tip very, very frequently while you're using it. It's
not just something you do at the very end while you're putting it away. So most soldering
iron stands come with a little sponge, SpongeBob, SpongeBob Square Sponge like this that's just
at the bottom of the stand. Just get that wet. Some people keep a little bottle, like
a little drinking water bottle next to their soldering station so they can always just
keep that thing wet without having to run off to get it into the sink. That's fine for
when you're starting out. You know, just rub it on that sponge. Rub the tip of your iron
on that sponge frequently, like almost every time you put the soldering iron down or pick
it up. Just constantly be cleaning it. And then as you get a little more into soldering,
kind of like a style point tool, you might get one of these little kind of shaved metal
tip cleaners. These are pretty nice. You just kind of stab the soldering iron into it. Scrape,
scrape, scrape. And it scrapes the tip of the soldering iron. You can just do that frequently
while you're using it. Every time you go to set the soldering iron down or pick it up,
just kind of stab it in there a couple times. So the nice thing about the metal, the kind
of... it's almost like a little Brillo pad. It's like a... I think they're usually made
of brass. And it's like metal wool. I think people call it metal wool or steel wool. It's
not technically steel wool. But these type of cleaners, the really nice thing about them
is because they're not wet, they don't conduct as much heat away. So that's really good.
Yeah, so those are probably the main tools you need. It's also nice to have some flush
cutters like, you know, these little guys, which are really very tiny. And one side
of them is flat so you can cut wires off flush to a circuit board. At some point, you will
want to be able to remove the residue that's left on a circuit board after you solder it.
You know, this is called cleaning the flux. So you'll want a flux cleaner or a lot of
people just use rubbing alcohol, isopropanol, and a little very stiff brush, an acid brush,
to just clean the back of the board. In the beginning, you don't really need to worry
about that too much. You can just clean it with a tissue or just, you know, don't worry
about it too much for a board like the one we're going to do today. But when you start
making circuit boards you want to be able to keep for a while, you want to be able to
take that residue off. And we'll discuss why you want to do that. So you'll want whatever
solvent you're going to use for that. Like I said, isopropanol is usually fine. And maybe
a little brush or something. And at some point you're going to want to have a flux
that you can deliver to the board. So flux is the thing that cleans the work. It cleans
the surface that you're going to be soldering on. It also breaks the surface tension of
the solder when it's liquid so that it can flow a little easier. So it's a cleaner and
a flowing agent. And flux is just kind of important. I've heard some people refer to
flux as grease. So if you've heard people say that, that's what they mean. But it's
not grease. It comes in a liquid or gel or it comes in little pen dispensers that look
like a fat magic marker. A lot of people these days really like the gel. It's become readily
available. I usually use the liquid just because that's what I've always used. And I get a
little dispenser bottle. Let's see if I have one of these. A little dispenser bottle. These
are extremely inexpensive so you can have a few of them loaded up. And you can see the
flux that I have in there is a liquid. So you're going to want some flux. Like I said,
there's a bunch of different kinds of flux. The most basic kind of flux is rosin. I don't
know if it says it on here. It says flux on there. I don't know if you can see it. It's
very tiny. But for the most part, all the solders you're going to use, we'll discuss
solder again in a second, they're rosin core, meaning they have rosin flux inside the solder.
So when you're using the solder, it's kind of auto-fluxing. It's self-fluxing. So you
don't need to apply flux from a pen or a bottle. But as you get a little more advanced in soldering,
you're going to want to have flux. But for the very beginning, using the flux that's
inside the solder is totally acceptable. You'll be able to get away with doing a lot of work
just using the flux that's inside the solder. But I'll speak more to that in a minute. There
are some things you have to keep in mind when you're using the flux in the solder. So that
flux is what leaves a residue on the board sometimes when you're done soldering. And you
might want to clean that off because the way the flux cleans the surfaces, it's usually an acid.
It's not a super strong acid, but it's acidic. And if you leave it on there, it's great when
you're trying to solder because it'll clean the oxidation and dirt and oils off of the work so
that your solder will flow. But if you leave it sitting on there for a long time, it might
eat into the board a little bit or pit the surface. And you know, plus it just usually
looks a little yucky. So it's kind of nice to clean it off. But for your first few projects,
and certainly for soldering this first batch, buddy, don't worry about that. But just know
what flux is. At the point where you want to start cleaning flux or using a separately applied flux
other than just the flux core in the solder, it'll come to your mind that, oh, I want this other
thing. And just worry about it then. You don't need to worry about that for right now. But yeah,
as far as the solder goes, there's a lot of different options when it comes to solder.
The basic options are tin-lead alloy. A lot of people call it 60-40, although there's slight
variations. They're not always exactly 60-40, 60%. I think it's 60% lead, 40% tin, or it might be the
other way around. I'm not sure. But let's see, it might tell us on here. 60% tin, 40% lead. That's
the basic solder. Like I said, it has a flux core in it. And this one right here, you can see it's
fairly thin. This is a 0.6 millimeter solder. I usually get 0.6 or 0.8 millimeter. I've used
one millimeter before too. That's fine as well. But you generally want something that's fairly
thin. If it's too thin, when you're soldering something larger like a connector or something
or something that has like a big heat pad or something, you'll find that you need to use a
long length of it. That's not a big deal. Just use a little more. Some people like to have a
thicker one for doing stuff like that and then the thinner one for doing smaller work. That's
not nothing you really need to worry about right now. One thing I do want to comment on is a lot
of people get caught up in the lead-free solder. And of course, we'll talk about safety in a little
bit. Lead is a potentially toxic substance. So if you're concerned about it, you can use lead-free
solder. I don't. Most people that are really into soldering really hate lead-free solder. It has a
much higher melting point. It's very annoying to work with. It's really hard to rework. It's just
not the best thing in the world. And if you're pretty careful, you know, you shouldn't be
sticking soldered wires or circuit boards in your mouth anyway or letting children play with them.
So, you know, you don't get lead inside of you by simply by touching it. You have to touch it and
lick your hands. Or you have to, you know, chew on the thing that has the lead on it. Lead doesn't
just float up in the air. So, you know, of course, you know, if you're working somewhere and they have
safety policies on this, you know, read your safety data sheets and all that. That's not
my expertise. But, you know, I can just tell you that most people that are soldering experts,
you know, they prefer to use the standard 60-40 leaded solder. It's just much, much easier to
work with. And lead has a very low melting point. So anyway, those are the kind of solder things you
need. Speaking of melting point, if your soldering iron has an adjustable temperature on it,
a common question is, well, what do I set that at? So I usually set mine right at about 350 degrees.
That's Celsius. Maybe a little higher than that sometimes. And that works out to about 660
Fahrenheit if you have an older rig that has a Fahrenheit rating on it. So yeah, just kind of
keep in mind like 350, 360, something like that. And you can go a little lower if you're working
on something really fine and you're worried about heating it up too much. Or a little higher if
you're soldering like some big screw lugs or something that needs a lot more heat delivered.
You know, if you kind of sense that your tip is getting cool too quickly, you might want to
turn the temperature up a few degrees. So yeah, remember that 350C or 660F will kind of keep you
in the right range for melting the lead tin alloy solder. If you decide to use lead-free solder,
you're going to need to go up a little bit. And you can find the specifications for whatever
solder you're using. It'll have a melting point, but the tip temperature needs to be much higher
than that melting point. So it'll usually have a melting point than a specified tip temperature.
All right, so temperature... soldering irons are really hot. So we joked before about the
chicken thing. I'm going to mention it a few times because you just want to be careful not
to burn yourself. There's a few safety points to keep in mind here. That's probably the one
that we almost don't need to mention. I mean, we're melting metal. Of course, it's hot. Don't
stick your fingers in it. Don't clean it on your tongue. All those things, right? So just remember
it's hot, okay? The next safety point... we're going to have four safety points. The first one is heat.
Don't burn yourself, all right? Don't burn yourself. Don't burn your desk. Don't start a fire.
Just remember it's hot. Heat. The first one is heat, okay? Number one, heat. Number two are fumes,
okay? And a lot of people think this has something to do with the lead. It doesn't. It's when you're
soldering, there's that rosin core in there. And the flux, that rosin core, it will gas off. It'll
make kind of a smoky smoke. And you don't want to breathe that, all right? So you want to have a
little... what I have on my workstation is I actually just have a small fan and it just kind
of blows into the corner. Because that smoke, that residue, it'll settle very quickly. So if you
just blow it away from your work, that's probably fine. I don't recommend this, but I've actually
noticed even with my fan on, just because I've been soldering for so long, when I solder, every
once in a while I'll just go... and I'll just blow the smoke away. If the smoke is rising up into my
face, I don't want to inhale it. So I just... and then I inhale. Probably not smart. Probably not
safe. Just keep the fan on. You can buy a really nice little fume extractor hood that has a little
like a filter. I think it's a charcoal filter in it that keeps the... gets the soot trapped. And
it's very nice. So if you're going to solder a lot, you might want to get one of those. You don't want
to be breathing those fumes, okay? So number one was heat. Number two was fumes. Number three is
lead. We already talked about the lead. So when you're soldering with lead solder, lead can get
on your hands. Just like, you know, if you were touching a lead pipe or something like that.
Also, little bits of lead break off. I think it's called dross. And, you know, maybe even...
they're almost microscopic. Sometimes they are macroscopic. But... and you'll even notice little
bits of... little tiny balls of solder around your work area after you've soldered a lot. That stuff
is called dross. And if that's sticking on your hands and then you lick your finger or you eat
your lunch and haven't washed your hands, that lead can get in you. That is particularly a problem
for children. So if you're soldering in an area where there's children, you want to clean that
lead up. So after you work with leaded solder, you need to wash your hands. Okay? And this isn't
a hand sanitizer situation because this is not... you're not trying to kill bacteria or something.
You're literally trying to wash a metal away and get it off of your hands so that it doesn't get
inside your stomach, in your mouth. Okay? And also, if you have these little dross bits and
there's a child that comes through your work area and they're very little and they might, you know,
drop a toy somewhere where you have these little dross droppings or whatever and put it in their
mouth. Or if you saw... if you've recently soldered something and they might say, oh look, that's a
cool badge buddy and stick it in their mouth. That's not cool. You don't want to get lead inside
you. You do not want a child getting lead inside them. Okay? It's not that big of a deal. There's
other things in your house that's lead, but you do not want little chunks of lead, you know, that
break off of things sitting around. Just wipe it up with a wet wipe. Wash your hands. Clean it up.
Just keep it clean. Don't get this lead around the place. Wash your hands after you work with
leaded solder. All right. So heat, fumes, lead. Right? Those are three things. And then this last
one is huge because people just don't think about it that much. But please wear safety goggles.
You don't want to get... you don't want to fling a little drop of hot solder in your eye. You know,
a really big thing is, you know, you're cutting your leads off, especially ones that might be a
little thick. And they go... and the lead flies off and it hits the wall. And you're always like, oh
that sounded nice. Well, that doesn't sound nice if it hits you in the eye. All right? You only get...
no, you actually get two eyes. Anyway, you probably want to keep both of them. So protect
them. Wear some eye protection. All right? You only get those two eyes. All right. So great. So
let's actually get the soldering now that we've covered sort of the theoretical background stuff.
And I guess this might be a good time for me to say there's a lot of great soldering videos out
there. If you just get on YouTube and look for things about soldering, you'll hear mostly all
these things I already said. But, you know, maybe you'll pick up some other pointers. And sometimes
it's good to hear things explained from different people. So, you know, if you like soldering and
want to get better at it, definitely watch some other videos. You know, we're only going to barely
touch on, for example, surface mount soldering. So there's some great surface mount soldering
videos out there that you can find. So that's a nice segue to our next thing. You know, I like
to think of there being three structures for soldering. Two of them we're going to do here
today. And that's through-hole soldering, when you have a hole in a circuit board, like, you know,
it's called a through-hole, a plated through-hole. And you put a wire or a post through it and then
you solder it into that hole. Right? There's through-hole soldering. And then there's surface
mount soldering, where you have a pad on a circuit board and you solder something onto that pad. So
it doesn't go through the board, it just solders onto the surface. And, you know, when you see
these, like, really large chips that have, you know, many tens or even hundreds of little leads
sticking out of the sides, those are all surface mounted, or these little tiny resistors that look
like little rectangles that don't have any wires, like, those are surface mounted. Today we're just,
we're going to do one really big surface mount thing, and that's our battery clip. But it gives
you the idea of what surface mounting is, so it's a nice exposure for that. So we have through-hole
surface mount. Through-hole is something called TH, sometimes called TH. Surface mount is often
called SMT, surface mount technology. And then the third thing is just, I guess I might call it
point-to-point soldering, and it's when you just solder two wires together. You usually strip the
two wires, twist them together, and then solder them, and making sure you get solder flowed
completely into the joint. Another example of that kind of point-to-point soldering is when
you're soldering a wire into a connector or something like that. So that isn't exactly
through-hole, and it's not exactly surface mount, it's just a different kind of soldering. But,
you know, if you always think of those three things, they all kind of work the same, but they
all have little, you know, differences that, and it's nice to make sure you get some practice in
doing all three of those. All right, so let's get right into this example. Actually, first let me
just say, you know, so the basics of soldering are, and we've already touched on this a little bit,
so I'm going to say these things a few times just to make sure they really sink in. So you have two,
let's say, let's say you just have two surfaces. You either have the hole with the wire in it,
which is, you know, the hole is a surface and the wire is a surface for through-hole,
or you have a pad with a terminal of a component sitting on the pad if it's surface mount.
So, but there's usually two things, right? The pad and the lead, or the hole, the through-hole
and the lead, the plate of through-hole and the lead. And what you want to do is heat up
the junction, so both of those things. You want to heat both of the things you're trying to connect
hot enough so that solder will flow onto them, all right? So there's a few things that you're
trying to do all at once here. So when you go to heat them, you need to have some solder between
the soldering iron and the connection. And this is not the solder that you need to flow into the
connection later. This is just the thermal connecting solder. So you have the two components
sitting together. So often what you'll do is you'll have the two components, you know, near each other
in some way. They're next to each other, either inside of each other or sitting on top of each
other. So you put the iron near them, get a little solder on it, on the iron, just so that that
solder can touch to the work and conduct heat into the work, right? So that's not the solder that
makes the connection. It's the solder that is used to enable the connection to be made
by allowing the soldering iron to then heat the items up, right? So that first little bit of
solder you put on there, you're really putting it on the iron and it heats up the two items,
that heats up the work, let's call it the work. And then once the work is hot enough, it's up to
that melting point of solder, then you touch the solder to the work, not to the iron, and the work
will melt the solder onto itself. And that's how you get a beautiful, nicely flowed solder connection
where the solder flows onto the work and is not just kind of being brushed on there by a soldering
iron, right? So again, you do not use the soldering iron to apply the solder. You use the
soldering iron with a little preliminary bit of solder on it to heat up the work enough so then
the solder melts onto the work, right? So anyway, that's a thing that, you know, when you get it,
when you get that really nice flow of solder on something, when you have the metal really hot,
and then the metal melts the solder, not the soldering iron. The soldering iron immediately
heats the metal up. The trick is you need a little solder initially to be able to get the heat from
the soldering iron into the metal or the work. So that's one of the main things you're doing there.
The other thing is, remember, your solder has your, especially, you know, if you're using,
you don't have a bottle of flux, you're just using rosin core solder, your solder has your
flux in it. So you need to be adding solder. I don't want to say constantly, but the process of
making the solder connection, you need to be adding solder because the flux comes out when you melt the
So before you make the connection between the two pieces of metal,
those surfaces need to have flux on them. So you have to melt the solder in their vicinity
so that the flux gets on them, and then that allows the solder to flow onto them. So the two
things kind of happen at once, the heating and flowing of solder and the application of flux,
because they're coming in the same delivery package, right? The strand of flux you're using
has the rosin, the strand of solder you're using has the rosin flux inside of it, okay?
And another important thing about that is, sometimes when you get solder on a connection
and you're moving it around or you're still working the connection in some way,
the smoke that came up, that's your flux burning. It's your flux boiling off. That smoke that came
up that got sucked away or that, you know, if you followed my incorrect instructions, you blew away.
So now that flux is gone, okay? So that's one of these things where you need to add more solder,
because the solder has the more flux in it, right? So if you're continuing to work the item,
you only have so long before your flux is gone, okay? And then, you know, if you get to the point
where you've melted a bunch of solder on it and there's this big mess, you need to take the solder
away, which sometimes you can just lift it off with iron. It'll stick on the iron and you can,
you know, clean it on your sponge or your metal tip cleaner. And then you can apply
some more fresh solder, which will have new flux in it, releasing a little more smoke.
So this is part of that thing I said, where you need to be always ready to put a little more
solder on, because you need the solder because it conducts the heat. You also need the solder
because it has the flux inside of it. And the flux doesn't stick around. You only get a few seconds
to use, to flux the surface with the solder. That's why, you know, you need to keep adding
more solder. Even if then you get to the point where there's too much metal on there, too much
solder, you just pull it off, just clean it off. You're going to need the flux. And when you get
a little more advanced with this stuff and you're doing a lot of connections, you know,
really small packages that have a lot of pins, that's where you just want to get a bottle of
flux and just drench the thing with flux or put gel flux on it so it's all soaked with flux. Because
then you can work it, you can move the solder around, you can add and remove solder, and the
flux is still there doing its job of cleaning and breaking the surface tension of the molten solder.
So this is the badge buddy. Comes in a Ziploc bag like this and there's some stickers in there.
We got this during Defcon 28. We did some sticker swapping. So there's a bunch of different
stickers in here from lots of our friends and members in the community and other vendors.
You see such as Hack5 and Hacker Warehouse and just random stickers. So that's lots of fun.
And yeah, let's see. Yeah, there's some good ones in here. Yeah, there's a Hack5 sticker,
a couple Hacker Boxes stickers, hologram sticker. Yeah, Hacker Warehouse gave us these. They have
some little camera covers on them to keep your camera safe. So all right, yeah, the parts that
are in here are fairly basic and represent opportunity to do a little bit of surface
mount and also some through-hole soldering. There's a bead chain that you can use to
connect the badge buddy to your lanyard or your backpack or whatever when you're done.
There's a coin cell battery. It's a lithium battery,
CR2032. It's a pretty common lithium battery coin cell. That's the
clip that holds the coin cell onto the back of the PCB.
All right, let's get these things out of our way here.
We'll solder these four items to the PCB, to the circuit board with
the logo on there. It's the Hacker Boxes logo. His name's Bithead or Circuithead, depending on
which version he is. So we're going to get some solder out. We're going to start by
tinning the tip of the soldering iron. This one's already tinned because we use it a lot.
Then we're going to tin these three pads, these surface mount pads on the board. But you want to
always keep the tip of your soldering iron tinned. Keep some solder on it. The flux will help clean
it. And every time you see the soldering iron going off the screen here, that's just me cleaning
the tip in a tip cleaner. So we're going to tin these three pads by just getting some solder
flowed onto them. And again, we're not just melting it on there. It's actually bonding into the
pad, the solder that's already on the pad from the manufacturing process.
And when you're surface mount soldering, well, with any soldering, you really want to
pay attention to the orientation. So this little clip is oriented according to the
white paint on the board that's called the silkscreen. So the board has been silkscreened
with these positioning indicators. And most boards have this. When you lay out a circuit
board, you can design the silkscreen. So the silkscreen shows you which direction that the
battery holder goes. And in this case, you could put it the other way. It's just a little harder to
put it in. So we intentionally oriented it so the clip opens downward. So now what we're doing
is we're getting solder to flow onto the little wings on the side of this battery clip, battery
holder. And we're actually heating the clip up enough so that solder flows onto it. So remember,
we need a little solder on there just to conduct into the metal of the clip. And then you can see
the solder flows really nicely and makes a nice shiny surface. So you want to make sure when
you're soldering, you always end up with a shiny surface that flows neatly onto all of the metal
around it. And that lets you know you do not have what's called a cold solder joint. If you just
dump hot solder on a cold metal, it won't flow onto the metal and it won't bond. And that will
be a cold joint, which is mechanically unstable and can be broken off pretty easily. And you do
you never want that. That's like the most important thing to avoid while you're soldering is getting
cold solder joints. But you can see these are nice, well flowed, well... it's called wetted.
The solder is fully wetting the board. So yeah, so the indicator on the silk screen for the LEDs
shows the flat side. So the LED has a flat side on it and the flat side goes to the short pin.
So the short pin is going through the board so that it lines up with the flat side on the
leads through the holes. And we're going to get them on the other side. And you can usually just
bend the leads a little bit to hold it in place. But then also we're going to set the board down
on the component side down, which will hold the pieces into place. And that's why when you're
soldering, you often start with the lowest altitude or the lowest thickness parts first.
Because then as you flip it over, you can get basically the table to help you hold
them into place. And then just things don't get in your way when you do that. So again here we're
just flowing solder. We're using a little tiny bit of solder to heat up the joint and then getting
the solder in there so that the heat of the joint melts the solder into the joint.
And there's just four little through-hole posts here. It's actually quite easy. And you can see
I'm moving pretty quickly because, you know, like I said earlier, you want to be able to
use the flux. And the flux will disappear over time. See, it's not smoking anymore because
the flux is gone. So while the flux is still in there, you want to get the work done. So you do
want to move a little bit as quickly as possible without creating errors or
making a mess. All right, now we're going to cut the leads off. This is where you need to be wearing your
safety goggles. And then some people like to go back. I usually like to do this and hit the
cut-off part with the soldering tip again just to get the solder, basically the wound that was
left behind by the cutter, just to make it nice and smooth. But, you know, that's your option. And the
switch is also through-hole. You can put it on the front or the back. I think since, you know,
it doesn't really matter. Putting it on the back means you don't have to see it. It leaves the
board looking kind of nifty. So you can just push it through those three holes here. If I can
get that to stick in there right. The leads are really short on that on that switch. And so here's
a good example where you want to get one of the pins soldered. And then maybe, you know, just get
one soldered here. And then maybe check and see, make sure the other three or the component is
lined up. Because, you know, while only one pin is soldered, you can reflow it very easily and move
the component around a little bit. This is important when you're doing like a chip that
has a lot of pins. You just get a corner tacked down and then you can move the chip around just a
little bit by just reflowing that corner. And then once everything's lined up, you can go ahead and
solder down the rest of them. But it's even useful for just a little switch like this. There's a lot
of play in those holes. You can move that the switch around a bit. So it just helps you line
it up nice and straight. All right, all three pins of those. And that switch is just an on-off
switch. It just opens the circuit between the battery and the two LEDs. And now these are not
just regular old LEDs. They actually have a little circuit inside of each of the things.
They're in an LED, a five millimeter LED package. But there's a little circuit in there that actually
cycles three different LEDs inside the package. So each of those packages, while it looks like an
LED, it's actually three LEDs and then a little circuit that will make some cool flashing patterns.
We're going to get this coin cell open. It's a lithium coin cell. I'll show you how to install
that. These are packaged really well because the manufacturer of the batteries doesn't want them
shorting out and causing any trouble. So they completely encapsulate the battery to keep it safe.
Anyway, we take that and we flip the positive side up. I'm going to show you there's a little
on the top. Flip the positive side up and that obviously means the bottom is ground.
And then slip it in there. And the part of the reason why we tinned that pad underneath the
clip is because the center pad actually becomes the terminal.
And there you go. That's Bad Buddy. Nice, beautiful blinking lights.
It's very colorful and the lights blink quickly and then slowly in different speeds. And if you
leave it on for a few seconds, the colors will get out of sync, which makes it look a little more
discotheque. It's pretty cool. Okay, so that was pretty cool. So I said we would talk a little bit
about... just give you some of the keywords about removing solder. If you need what's called
rework, meaning something's already soldered and now you need to rework it or reflow it, you need
to heat the solder up so that you can take the parts apart. Sometimes you want to remove the
solder. So you can use this thing called solder braid, which is basically just this really finely
braided wire, and it has a lot of flux in it. And it'll suck... if you just put it between your
iron and a piece of work, once it gets warm, it'll kind of draw the solder out of the work.
You can also use a solder sucker. One of these guys right here. So you create a vacuum in there
and then when you trigger it, it sucks the solder out. So yeah, I wanted to point out when I did
that, a couple little chunks of solder flux flew out of there and you do not want to eat that or
leave it where a child might need it, okay? If you get that on your hands like I just did, you
want to wash it off before you eat or, you know, floss or whatever you might do that might get in
your mouth, all right? Yeah, so braid, suction... just remember you're going to need more solder
either of those things you're doing. You need more solder, you might need flux. Again, you know,
you'll figure these things out, you get to them. Just don't be afraid to use more solder. Don't be
afraid to get some flux going on things when you need it or add more solder to get the flux
melted in there. All right, so hopefully this is useful. There are a lot of resources online you
can find about soldering. If you have any questions, you know, hit us up here at Hackerboxes.
Yeah, and like I said, I hope that was interesting. I hope you're open to soldering some more
projects. You know, we sell a lot of kits at hackerboxes.com and there are a lot of fun things
out there to solder. Even if you don't get them from your actual like kits, just things that you
might want to rework or modify or try to repair. You know, like I said, it's a very handy skill.
I hope you enjoy it. Thanks for spending this time with us. Take care.