Hi Welcome to the Eev Blog an Electronics Engineering Video Blog of interest to anyone involved in electronics Design. I'm your host Dave Jones Hi It's Surface Mount Soldering Time Part Three in the Hands Soldering tutorial and today we're going to do surface mount technology. We've looked at the tools in the first part, uh, through hole components in the second part and surface mount. A lot of people think it's really hard, but it's not.

It's an absolute piece of cake. Use the basic techniques you did last time, few more little tricks and you can solder really first class stuff with not much experience at all and some very basic tools. Let's take a look at it. Let's start out by looking at some basic surface mount components.

Here Up here is your standard Quar Wat through Hole resistor everyone's familiar with. Now this is a 1206 size uh, Surface Mount resistor. This is a a 85 uh surface mount ceramic capacitor. This is an O the same size 0805 surface Mount resistor.

This is an 0603 surface mount resistor and this is an 0402 surface mount resistor. They do come even smaller than this. Tiny ones that are used in really Ultra miniature mobile phones and things like that. Now the 126, But these are the basic standard sizes that you'll deal with.

Um in terms of Um, in terms of your basic resistors and capacity is your basic passive components. Now the 126 up here is an absolute monster. Stevie Wonder Could Solder this thing. It is so damn easy.

Let me tell you now. 0805 Really, very easy to do Um As as well once you get down to 0603, gets a little bit more touchy. but I can easily do 0603 by I I don't need any magnification at all and you should. Yeah, most people will generally be able to uh, solder and 0603.

So if if you're designing your boards especially for uh, hand soldering and even for surface mount soldering as well, try and avoid the 04 O2s now I can do those by I Uh, just. but I much prefer to use um to solder under um either a Time 4 or a Time 6 magnification there. Uh, just so that I can you know just so that I can keep a much uh tighter uh control of how much solder feet on the The Joint and uh and just inspect the joint at the same time as I'm doing the component. So if you're designing your own boards, I would stick to 0603 and up.

um because the uh, once you get down to 0402, if if you're actually getting um, Pcb's hand assembled prototype, they'll charge you a lot more for 0 402s cuz they will generally sold to them under the microscope as well. Whereas if you're getting some prototype board hand solded 0603 and up, they can do by I. So uh, really, just put some thought into which components you use, don't just jump right in and use 0 42s. Now for today's example, I am just going to solder an 0603 part and if you're talking about automated pick and place assembly of your boards when you're designing your boards, put a bit of thought into it once again.

Uh, if you use 0 402s, you might be in trouble because there are basically two classes or two technologies of surface mount pick and place machines. Um, cheaper and older designs can only do 0603 and above components um to a to at least a reliable Uh level. they might be able to do 0402, but their yield isn't as good. Um, so if you're getting your board assembled by a manufacturer, they might actually charge you more to use uh to Uh Place 0402 components cuz they might have to use one of their more advanced machines.

Uh, the yield might not be as good and things like that, so just put a bit of thought into it. It might cost you a bit more to go down there, so don't make it an arbitrary choice to go to 0 402s, Make sure you have a reason to do it. Now here's our 0603 resistor that we're going to solder onto this board. and as you can see, it's going to be fairly easy because the pads are actually quite large in comparison to the component.

They do actually extend out further and this is great for hand soldering. Now, if you're going to, if you're laying out your own boards like this, the Um IPC Footprints The International Standard Uh Footprints They actually come in three basic sizes what's called uh, normal, least, and most pad size now I'd Recommend using the Uh, normal, or the most pad size. Most means it's got the largest pad size and they're the ones that are suitable for uh, getting your eyon in in there to make contact with both the pad and the Uh and the end cap on the component at the same time. And that's that's important if you use uh, the least pad size or even a custom pad size.

Some pads are really no bigger than the tiny little end cap on that resistor. and really, there's no way that you can actually get your iron in there to make contact with both. You could put solder on the end and bring it over and maybe get under there and actually thermal, or even uh, thermally, transfer the heat through the cap onto the pad and it gets really nasty. So just if you're actually designing your board and you think that they may be reworked, hand solded, or they're going to, prototypes are going to be assembled hand solded if if you can afford the room on your board.

if it's not a super compact layout, highly recommend you go for a larger pad size so that you can get that thermal contact now. Uh, we're going to use a Conta We're going to use a method today called the Uh Tac and Reflow method. Uh for doing these components and it you. As you'll see later, it applies to other parts as well.

It basically uh, it basically means that we're going to tack the component down first and then sold to the uh other side. And if I'm doing a whole array of components like this, I will do it in like a batch process. Um, as asual. I'll do a single resistor here, but if I'm doing a whole bunch like this, uh I would go through and apply solder to I'll do one step, apply solder to all these pads first and then I will go and place my resistor and then uh, tack it down T and Tack the resistor down onto each PAD as a second uh, batch step and then I'll flip my board around to the other side.

Or if you're left-handed if you're am ambidextrous, you can solder with both hands. you can, uh, then you go through and you complete the joint on the other side. So that's a batch process, but I only show a single resistor today. Now, we aren't going to need any flux for this cuz there's H flux built into this uh into the core of the solder here.

So let's actually just apply a small small amount of solder, just a tiny amount onto that pad there and that will allow us to tack down this component. So if we grab it with the tweezers like this and we get in there, it's important to, uh, make sure the component doesn't flip up like that's hard on the camera I can't get my tweezers down vertical but if I get my resistor in there and I just Reflow it like that and really, we've soldered one side of the resist there beautiful and we just flip our board around like that and we go in, grab our iron again, and get in there with our once again I'm using uh, very fine solder 0.46 mm, uh, solder tiny stuff I Highly recommend you get that size or smaller for this kind of surface mount workor. forget using 7 or 1 mm solder. Really, you're going to do a horrible job.

You're going to feed too much solder in there. it'll It'll just look very amateurish. It'll be horrible. Trust me.

Spend good money, get good quality, fine solder, and we're going there. and we just there we go. We just tack down the solder the other side of that component and Bingo! We've solded an 063 uh, surface mount resistor and it's the same for a capacitor. It's the same for 0402 size 1206, 0805, whatever or it's um, also very, uh, similar for other components like a So 23 um and things like that.

so it's really quite easy to sold of these components. Give it a try. piece of cake and after You' solded small parts like this, you just want to get in there with your uh, jewelers, loop one of these or your inspection microscope or something like that and just check that uh that the resistors are solded nicely. Just pick.

and once again, it, as with any solder joint, should be nice. Uh, shiny. Uh, very nice, shiny and smooth. uh.

finish. And and it should have a very nice fillet there on either side of the resistor. That one there's slightly crooked, little bit off center, but generally that's not a bad uh job at all. Okay, now let's try and solder this.

Uh, very typical. uh, eight pin. So package I see here. Very easy to do by hand, even if you're not.

even if you haven't done SMD soldering at all because the pin pitch is reasonably large, it's um, half that of a standard uh dip base I See, instead of .1 in, it's 05 in or 1.27 mm pin pitch in the metric Um scale and that's actually quite large and you can get in and um, with your solder inine and actually individ and solder. very fine solder and solder each individual pin. This is one way to do it. Do it.

There are other methods as we'll see uh which are better used on um, smaller pin pitch. Parts but these so packages I like to just um, solder each indivi individual pin by hand with my iron. And how we're going to do this is we're going to use the Reflow, the Uh, Tack and Reflow soldering method. So I'm going to put my iron on there and I'm going to just uh, tin that little pad there.

it uh, it needs to be sort of um, you know a re a small size, uh, lump of solder on there? It's you, you don't want to Tin it completely flat cuz then uh, there won't be enough solder on there. uh to actually tack down your component. And the whole idea is that we want to bring in our component. This is where our our tweezers can come in handy and we want to actually tack that pin down on there like so and that holds our chip in place and we can solder the other pins, flip that around to the other side and we just want to solder the diagonally opposite pin.

So get your iron in there chisel tip which heats up the pin and the Uh pad at the same time and just apply a small amount of solder in there and it will, um, you can. It'll will just flow onto both the Uh pin and the pad and you should get a nice a very nice fillet. um in there it's hard to get. uh I can't really zoom in much more than that, but uh, you should get a really nice um shiny finish as well with no uh burs and no things sticking out.

No shorts to other pins because we've got the um solder mask on these boards. Solder mask is vital for surface mount uh, soldering work. This is the red material that you see on the board, but it also comes in um, other colors. you've seen that green and there's uh, blue and there's black and there's yellow and there's white and there's all sorts of colors that you can get.

But soda mask is vital because the soloda mask will actually go between each individual pad like that and it will prevent. It will help prevent unless you're really baded. soldering. Prevent: uh, shorts between the individual pins and that's really important as we'll see on the much finer pin pitch uh components.

But as you'll see, I can sort of. you know solder all I Want on try and attempt to put solder onto this this solder mask. It'll blacken but it will never, ever take and uh by having the solder mask in between the individual pins like that on a board. It just um helps keep the solder out.

Um, because it's not uh, sticky at all. The solder will uh, just naturally want to flow into the individual pins and not get stuck between the pins. place our iron there once again for a second or two just like a through hole work and apply the solder not to the iron itself. although it's hard when you're at this sort of um, pin pitch.

but uh, apply it to the pin or the pad if you can get access to the pad and uh, it will flow onto the joint like that. Bingo We have one side nicely soldered and with, uh, practice, you can do this incredibly quickly um, just as quick or even quicker than uh through hole work and then we'll get in there with our jewelers loop and we'll just have a look uh to make sure the solder joints are good and we can actually, um, see that there's no shorts in there and as you can see, I got a little bit of um solder Splash onto this pad here. you got to be careful not to do that. Um, it's because I'm working under the camera here and I had to use a shallower, uh angle soldering iron.

The Shallow: a shallower angle than I normally would. but as you can see, those joints have turned out quite nice because I've used 46 mm solder I've used a nice chisel Point soldering iron which allowed me to hit the pin and the pad at the same time. I Was able to get in there nice and quick and that is a nicely solded surface mount chip and it really is easy. Give it a go now! let's try and solder a much smaller pin pitch of 0.65 mm pitch device.

Let's see how we go and remember it's got the solder mask in between the pads. Let's start out by tinning one of the pads shall. We There We go and this will allow us to Reflow what's called Reflow our part into position because this is the Reflow soldering process because there's already solder on the pad itself and all we do is heat it up be it with a soldering iron or with an infrared Reflow oven or a toaster oven as you may be familiar with a lot of people. Uh, use those and this is how they Mass assemble boards after they pick and placed them using the Reflow process.

We've done a very similar thing here or an identical thing, but we've just used a hand soldering iron and with this pin pitch I'm not actually using any visual magnification at all I'm viewing this on the camcorder um screen here, but I can solder these by I Okay, let's try and Tack down the other corner here, shall we? If we can get in there, there we go. I Think we've tack down the other pin so that chip can't move anymore. It's secured in place and we can solder the other pins even on my alignment's a bit off there. I may need to uh Reflow that and uh, just shift it slightly so there we go.

I'll just Reflow that and just move the chip gently into place until those pins line up. Perfect. Now there's one thing I forgot to use here and this is was the flux pen. I probably should have with these surface mount parts.

These surface mount ic's like this um I probably should have just pasted on a bit of a layer of flux before I actually onto all the pads before I solded that chip into place. but I'm just going to apply some just after the fact here. I'm just going to wet that a little bit on there. so um, to help the solder? uh, take to that when I Uh, drag it right across with my well-based tip and there are you can actually see the residue, the flux residue all around there like that I Sort of overdid it a bit there, but you can actually see it's in place.

Too bad it's not actually under the pins, but it could actually uh, flow back under and that will be good enough. Should be good enough. Okay, here we go. Let's feed some solder into the well here until we've got just enough to sort of, uh, make it.

um, sort of just swell out the bottom and let's see if we can do this. Bingo Look at that magic and there you go. That's almost a near perfect solder joint on each and every one of those pins and all I did was drag the solder and iron across I actually dragged it across a couple of times cuz I didn't get it First go. it's a bit hard under the camera and I haven't practiced today, which is something that you should do before you, um, start out on an important board.

Just even no matter how experienced you are, just do a little practice run. Now as you can see, we do have a tiny little bit uh, two pins shorted together there, but we can get our trusty solder Wick this is the really thick stuff. This is where the super fine stuff would come in and we'll just Wick that away Bingo gone and we have a perfectly soldered 65 mm pin pitch and I don't know if you heard that on the camera. uh but there was a lot of uh Sizzle there as well as the uh flux uh, burnt and the flux is really the key to doing this.

I'll try and do exactly the same thing on the other side. okay, but I won't use any flux and let's see what happens. Now that one turned out okay, there's one little solder Bridge there uh which I can fix up with either the uh solder Wick or I can just come back in with my wicking tip. Okay, and just that will just uh, suck.

that should if I can get in there, suck that away like that. Now that turned out all right, but uh, it took a few swipes it. it didn't seem as clean to me. um because the other side that had the flux on it just seemed to uh Reflow much better I just much preferred that.

So the flux can be really handy unless you got like a brand spanking your board fully clean, you've got a uh, a brand spanking new component and um, you know, no oxidization. Then you can do without the flux. But flux really helps. But there you go.

That's how you can solder a .65 mm pin pitch. Uh, you'd have a hard time doing those uh individually with each pin, you'd probably have to do it under a microscope to get a good result. But with one of these, uh, well based um tips, these things that actually have the well in them that Wick the solder away these wicking tips. They're great.

Now what we're going to have a go at is uh, soldering this pick 24 FJ Not that it matters, it could be any uh chip, but it's a P 24f uh5 mm pitch quad flat pack. Let's see how we go. First thing we're going to do is just put some flux on these uh pads. Now you can use a liquid uh base flux if you want.

and uh, really, because we've got the gold flash. uh, pads here? you don't necessarily, um, have to use flux like this. but uh, I'm going to anyway because flux is always a good thing. Trust me, it's the key to good surface mount soldering like this.

We're going to use our Tack and Reflow method here here. So I'm just going to put a little bit of solder on that second pin there cuz I didn't have to worry about getting it on the first one there and we're going to tack that component in place in at least two corners and we'll just Reflow that pin there. There we go and we'll just T and we'll just tack solder a second pin there. We can clean that up later.

It doesn't matter if we've got a short there and just to be sure, we'll add some more Lux along there because you can never have too much. Now the technique we've been using here is called drag soldering as You' see, we drag the soldering on over the pins and I've showed you it with a well-based uh tip. but you don't have to have a world-based tip. You can have a standard chisel like we've been using.

Now, what you can. In fact, some people say it's better to use a chisel, but well, I don't know. Um, take your pick really. But we can do drag Bas soldering with a well, uh with a regular chisel tip as well.

Let's give it a go. Here we go. We got a 0.5 mm pin pitch part. This is quite a very small part.

Pretty much as small as they get, so we've got some solder on the back side of that. Let's give it a go. There we go. It's not necessarily the cleanest result there.

Um, because there's probably a bit too much uh, solder got on the on the pins, but we can actually clean that up. You can actually drag the iron back out like that and get the solder off those pins. No problems at all. But look at that we've created.

we've solded easily solded a 0.5 mm pin pitch part and granted, it's really easy if you've got uh, these larger longer pads that you can actually get the iron onto. So if you're laying out your board like this, for these 0.5 mm quad flat packs, it doesn't matter what size this can be a big two or 300 pin quad flat pack and you'll solder it just as easily and just as quickly. And to finish off this chip, you would just do exactly the same thing on all four sides and clean it up with a little bit of solder. Wick if you have to or as I showed just dragging the iron back away from the pins.

Now this one really helps because it's got really long. It's a prototype board so it's got really long um, pads like this and uh I don't recommend you when you're laying out Footprints to make them this long, but something like these pads over here uh is would be a really nice size exposed pad there so that you can get your uh chisel tip iron or the solder, the molten solder, the ball of solder either in your well or on your chisel tip. um so that it actually makes decent uh, contact thermal contact with the pad itself as well as the pin and then with the flux. It all just flows beautifully and it all has to do with this surface tension of the solder.

Because you some people look at this and they think it's just amazing how you can solder a 0.5 mm pin pitch part with a couple of millimeter diameter chisel tip like this, you would think it's impossible. Well, it's not. It's because of the surface tension of the solder. It just wants to stay on the iron.

Um, either or stay in the well tip or the Chisel tip and it doesn't. as we showed, it doesn't want to stick to the solder mask the red solder mask material which is between the pads and it wants to, uh, actually just Reflow onto the pads itself with the flux there to help clean it. So really, it's it. It is almost like magic and there's no trick to it at all.

It really is that easy. and if you don't feel comfortable actually dragging your iron all the way along these pins, especially the very large packages, you don't have to actually drag it along. You can, actually, um, just drag uh, the individual pins backwards as we saw like this. You can actually just get them like that and just touch it in like that if that's another technique you can, uh, use.

It's not as quick and efficient, but um, you you can actually, um, say that it is a bit uh uh. it's a bit more precise than the technique of dragging them uh, actually across the uh chip like that so you can drag back. It might take you a little bit more, but you can actually get a bit more a bit more precise feel and there you go. just that.

simple application of the iron. um, we have pretty much perfectly soldered one side of that quad flatb and as with any solder joint, each one has to be a really nice shiny joint with H a really nice fillet. it's it's really hard to get sorry I can't actually Zoom any uh, closer like this under the camera. but uh, you can see that really? that only took took me a couple of seconds and each joint is pretty much almost perfectly formed.

And as I mentioned in the first part of the tutorial, my soldering iron there is set to about 350. You certainly wouldn't want, uh, any higher than that. anywhere from 300 to 350 is is really going to do the trick for uh uh for fine surface mount work like this because if you make it too hot, you can actually lift the pads. You have to be careful and especially if you apply too much pressure if it with your iron.

If you come across here and actually apply a lot of pressure as you're sweeping across like that, uh, you can actually lift the pad so just be careful that you apply very light pressure and in. And in the case of the uh, well based tip, you really shouldn't even need to touch it as long as the uh, the molten ball of solder actually makes, uh, contact thermal contact with the pin and the pad, it's going to Reflow So really, you should shouldn't be having any pressure at all on there if you are just very, very light. There's another technique that some people like uh to use and you can actually use uh solder. Past this is, uh, just some basic solder paste with a little um in a in a syringe like this and uh, you can actually just apply a small amount of solder paste either either before you lay the chip uh down or or you can even do it after which.

I'll show an example of here, but you really have to get just the right amount of uh paste on there, otherwise you end up with too much and then you've got to clean it off. But anyway, let's give it a go. Let's see if we can apply a small amount of paste across here. It's got It's quite hard under the camera here.

but anyway, let's give that a go and see what happens and you can likely hear that. I've got my um uh hot air gun here once again set to about 350 and uh with a reasonable air flow on there. And let's heat up this and see if we can do it. normally I'd get this right down vertical, but uh I can't do that with the camera in the way.

unfortunately on this, but it should. There we go, there we go. it's finally reflowing Bingo and that's not a bad result I'd say I used slightly too much, uh, solder paste there. As you can see, it's actually quite hard to dispense the correct amount of paste.

And and of course, this way this is where you get into solder stencils and proper Reflow soldering with a thermal oven which won't be in this tutorial cuz this is about uh, hand soldering. It's not about um, doing a solder paste, uh, stencil. but um, there you go. You can actually use a syringe based uh, paste and once again, you can go along with your iron or your Wick later and you can actually clean up that.

um, generally you're going to end up you're usually going to end up with more solder than, uh, not. Generally it's it's hard to put a very tiny amount on there unless you've got a specific past dispenser. You can get, um, automated, uh, pump based dispension. They only dispense a certain amount of paste and you can go along and and actually apply it to each pad.

You can go along and go bang bang bang bang on each pad. like a little drop just before you place the chip down. but geez, if you're going to do that well, you probably may as well do the Um stencil as well. But there are some cases where you actually want to rework uh boards with components all around where you can't actually get in there and do AA or it's not as easy to use one of those solder paste uh stencil so you may have to use one of those um pump solders paste uh, solder paste based dispensers to just dispense the correct amount of paste on each uh pad and you can actually get machines to do that uh as well.

And I've got another video which I'll link to here which uh actually shows you a very expensive High end machine um, that can actually dispense paste onto individual pads in a fully automated type process and that's good for reworking BGA components and things like that. Now you'll notice that I've been using a goldplated or gold flashed uh, prototyping board here. Now if you're going to do really high density uh F surface mount work I Highly recommend that you get your boards manufactured with uh, these gold uh flashed pads because it is just a it's easier to solder to. Everything takes better the flux takes.

You don't have to use as much flux, it's just nicer. it doesn't uh, doesn't corrode as much and it's just uh. and the other thing is that it is a much flatter surface and that's quite important when you get down to quite fine pin pictures. you can get finer stuff than this.

And if you get Bgas, it's actually quite important that you, uh, that that the chip actually sits on all the pads quite flat. Now, now, if you compare that with a, um, what's called a hot air level um, solder finish board, Here's a typical one. It's it's not. uh, it's not the gold flash, it's just a solder.

A 10 plate solder finish on the pads here, and you probably can't see it under the camera there. But the Finish is uh, it is lumpier and um, and the chip doesn't sit as flash if flush, um, as flat to the board. And if if you've got like a BGA or something like that with the little balls in there, um, if you just get one pad that's got a bit of excess, uh, solder on it, then you're going to get a horrible result. So really, it doesn't cost all that much more.

Um, you know it might even cost a few cents. Uh, per board. really? To get the uh, the gold flashed pads I Highly recommend it. Now let's try and solder on this.

uh, a higher thermal capacity dpack here. The others have been really easy because So9 hasn't sweated the smaller stuff at all. Uh, But as you can see, this, um, large, rather large device has a huge uh pad on the bottom and a matching pad here which is connected to a well. It's a reasonably large, uh, little, um, uh heat sink here.

a sort of a heat sink ground plane. so let's solder that in place and see if we can do that at the same solder in temperature we used before 350. C with the Um chip our our chisel tip we uh, used before and see how we go on that, see how long it takes to solder uh, something of this thermal capacity and of course we're going to want to have to, uh, tack this in place as well. so we'll just put a bit of solder on that pad there and we'll just bring our device in and we'll Reflow that in place.

No problems, do the other pad. Now as you can see, we don't actually have any pad area there to actually apply our solder to our well, our iron to. so we really have to, um, apply, put the iron on top of the leg, apply pressure, and feed in solder from the bottom like that, and it reflows onto the pad, and then uh, onto the leg as well. Now I'm going to use my standard uh, chisel, uh, mediumsized chisel tip here.

I've still got my IR set to 350 as we've been using up until now, but I've got this large amount of copper. Let's let's see how it goes now. One method to actually do uh, even well larger devices like this and this is actually quite a small device? A dpack. Um, you know, if you got a large to220 and you're trying to solder to the tab or something like that, you may actually want to preheat it.

Uh, what's called a preheating process where you would, um, that's where your uh hot air gun might come in handy. You would actually heat up up all of the surrounding copper and the pad and the component first. and then you can get in there with your solder and require less time. But anyway, let's uh, let's not.

uh, discuss that today. Let's actually get our iron in there, try and get it on the pad and the device as well at the same time, and let's try and get our solder in there. Now at the moment you know we're trying to apply it to the pad and that's really not, uh, working that well. This is where.

okay we're going to have to put some solder onto our onto our tip like that so that we're we can actually, uh, better thermally couple onto both the pad and the device. So we've now got solder on there and you can see it already starting to flow onto the pad and there we go Bang. It's starting to flow along and it's starting to heat up both, but as you can see it's taking a bit of it's taking a bit of effort. You can actually see parts of it cool while the others actually heat.

it actually heating up and is molten. The other end of it just instantly cools and solidifies. Look at that. But there you go.

We've actually now completed that. but uh, this is actually this isn't ideal because it's only, uh, actually attached to the top. We haven't actually reflowed any under the bottom. This is where uh, some thermal paste uh would come in hand to actually put some paste on the bottom of that device.

and then you would actually Reflow that with your hot air gun on top. But anyway, that's that's not. That's okay for just a simple, uh, prototype. But of course I'm not entirely happy with that.

look. It's it's. it's all lumpy and it doesn't. You know it's all craggy.

I Don't like it. It's not as shiny as it should be. so let's get our iron back on there. shall we try? And H we we try and get this one flat to apply a much much more even heat.

So we'll leave it there for 5 seconds or so and we can heat up both the pad and the device. And this is where we might want to turn our temperature up a tad. Um, but as you can see, we're um, already starting to get a much better, uh, a much better wet in between both surfaces there and we've probably got a little bit too much solder there actually. Um, so it's not going to look perfect, but that is better than what we had before And there you go.

That is quite a nice, uh, shiny smooth result there. and that device is still hot. Um, it's still very hot after the process. But these larger components can, actually, uh, take more of the heat like this and they will actually, uh, trap the heat for longer, so just, uh, be careful not to touch them cuz um, after you've solded them cuz they will still be hot, retaining that heat as part of their thermal capacity.

That's their job Now with these. uh, small components like these. these passive components, they can be quite easily damaged by excess heat. You have to be very careful with them.

Um, because there's no thermal capacity in there at all. So uh, so most of the temperature of your iron is going to go straight into that component very quickly. Uh, multi-layer ceramic ceramic capacitors are one example of components that can be really damaged uh, very easily with excess heat. so you want to be very quick and you want to use as lower temp temperature as you can get away with with these devices.

Um, Otherwise, you can lift the end caps, uh, off them and um, and your boards as well. Your F Fr4 uh PCB material. You can get different uh temperature grades which will handle heat. Uh, better than Uh.

Some will handle heat better than others, but if you got a poor quality Fr4 material that uses poor poor quality glue and resins and things like that to actually stick the copper down to the Fr4 for material, then um, really? you? um, these pads can actually lift straight off the board if you have excess heat or leave it there for too long. So just be aware of that. Let's actually see if we can do that. I've turned the solder iron up to 450 C and I'm going to heat up this pad here now.

It could take a little bit and uh, especially it it it does it a lot when you, uh, when you're doing rework and stuff like that if you have to rework several devices. but there we go. Bingo It's gone. There we go.

we've lifted. Check it out. We've totally lifted that pin up. It's bugged.

Look at it, see it's just totally floating and hanging on to to the trace like that. Thank goodness that that the copper actually still hangs on there so you can actually um, if you're very careful, you can actually push push those back into into place. If you do lift them, can push it back into place and then still solder your IC on top. But you got to be careful of that.

That's what can happen with too high a temperature. I Told you it was easy. Look at that5 MM pin pitch Parts Why Be scared of it? You can do it in a couple of seconds with just very basic tools and hardly any experience at all. It's unbelievably simple.

Now, we didn't cover uh, solder stenciling which is a different Uh technique and put it in in the Reflow oven and things like that. Maybe we'll cover that uh, sometime in the future, but this is just hand slding and you need good hand soldering schools. Even if you're going to uh, stencil and Reflow your own boards cuz sooner or later you're going to have to rework uh parts and rework. Soldering techniques are slightly, uh, different as well, especially removing Parts Maybe we'll do another tutorial on just reworking Parts But hand soldering skills very important and there's no need to be scared of any components like this.

Surface mount components are easy to do. Basic chisel tip: uh, soldering iron, some fine solder, a well-designed Uh board with well-designed pads, and uh, the solder mask. Make sure you get the solder mask between the pins when you're laying out the board. Watch for solder M expansion go Google that to I think I've probably done that in a previous Uh tutorial.

solder mask expansion is important to get that right, but if you get those things right, you can solder all these boards you yourself at home very quickly. Very professionally simple basic tools. So there you go: I Hope you learned something and go out there. Don't be afraid of surface mount.

uh Parts they're a piece of cake. See you next time and don't forget your flux! Flux is everything.