Canyou handsolder 0203 SMD parts? - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: August 19, 2018, 11:23:11 pm
content: Or do you need a special tool to handle them and use solder paste. Does hot air just blow them away? I have a feeling someone here will say they soldered them with a soldering gun and plumbers solder all the time.The circular caps are smaller then most for scale. I think they are 0203

author: Nusa
author_rank: Super Contributor
timestamp: August 19, 2018, 11:33:43 pm
content: Anyone who uses plumbers solder on electronics isn't going to have working electronics for very long.But yes, it's possible to hand-solder those. Most would need vision enhancement to get it right. From what you've said about your vision in previous threads, you certainly would!

author: Syntax_Error
author_rank: Regular Contributor
timestamp: August 19, 2018, 11:36:02 pm
content: Watching lots of Louis Rossmann's videos shows him solder just about any size component with nearly whatever he damn well pleases. This is a bit of an exaggeration, but not too great a stretch. He uses hot air and an iron as he chooses, and I have watched videos of him using either or both to solder both tiny and large components.TL:DR, it can be done. 0203 is so small, and I have not tried it myself. But maybe try with a small iron tip and see what you learn?

author: wraper
author_rank: Unknown
timestamp: August 19, 2018, 11:50:24 pm
content: Quote from: Syntax_Error on August 19, 2018, 11:36:02 pmHis soldering skills are frankly crap and he admitted it himself many times. It makes me cringe every time when he solders QFN with applying excessive amount of solder on a center pad first and then pushing IC on top, forcing solder to squeeze out. Also he uses order of magnitude more flux than needed but it does not matter much as it gets cleaned away anyway.As of 0201, if using solder paste and not too high airflow, holding the component is not needed. Otherwise hold it with tweezers until solder melts, then liquid solder surface tension will be enough to keep component in place. Frankly soldering 0201 is not that tough, 01005 is when it gets tricky.EDIT: I think you mean 0201, not 0203 which does not exist.

author: schmitt trigger
author_rank: Super Contributor
timestamp: August 19, 2018, 11:56:08 pm
content: The most common, nearest Standard sizes are 0201 (0603 Metric) or 0402 (1005 Metric).But even those are large compared to the 01005 (0402 Metric).EDIT:wraper responded faster than myself.

author: Beamin
author_rank: Super Contributor
timestamp: August 21, 2018, 06:23:31 pm
content: Quote from: Nusa on August 19, 2018, 11:33:43 pmThat is a picture I took with my cell phone of my magnifier's screen with my lap top under it. At full zoon a 1/8 watt resistor is magnified to 18" long. You can also turn it to black and white and high contrast to see things you normally couldn't like the laser etching on parts. It uses both opical and digital zoom with a table under it that has an electromagnetic lock to keep the work in place. Costs a few grand but worth it.I'm not sure of the actual size of those three parts in the picture. They are almost invisible to the naked eye and didn't even know they existed until I got the magnifier. How would you figure out polarity take then out of the package and remember because once you put it down there is no way of knowing?

author: wraper
author_rank: Unknown
timestamp: August 21, 2018, 06:35:53 pm
content: None of those parts have polarity. Parts which have polarity do have some sort of polarity marking. Also they generally don't come in really small sizes.

author: capt bullshot
author_rank: Super Contributor
timestamp: August 21, 2018, 07:36:10 pm
content: Yes, been there, done that (but using a reasonable sized tip and 1mm solder). Anyway, no fun for my "old" eyes, ten years ago I'd have said "peace of cake". I wouldn't recommend paste and manually applied hot air, the iron works better.

author: mdszy
author_rank: Unknown
timestamp: August 21, 2018, 07:45:40 pm
content: If these SMD challenge boards are anything to go off of, seems like anything is possible if you're willing to try

author: wraper
author_rank: Unknown
timestamp: August 21, 2018, 07:46:08 pm
content: Quote from: capt bullshot on August 21, 2018, 07:36:10 pmSolder iron certainly won't work better for solder joint quality. Also MLCCs experience a lot of stress and may develop microcracks when soldered by iron, it should be avoided when possible.

author: technix
author_rank: Super Contributor
timestamp: August 21, 2018, 10:20:07 pm
content: Painstaking but doable. You will need vision enhancement and a steady hand.For me I have no worse than 20/20 vision so no vision enhancement other than a 15W LED lamp on a moveable balanced arm lamp is needed most of the time. Steady hand takes exercise really.

author: Beamin
author_rank: Super Contributor
timestamp: August 21, 2018, 10:25:15 pm
content: I wonder what is next beyond 01005. They must run into limitations like cap size and max resistor heat dissipation. But fine in the world of 1.3 volt logic chips. Does the pick and place have tiny 01005 adapters and use electrostatic attraction instead of vacuum?Do the SMD resistors have a watt rating? Or is the idea that all these parts will just have small logic level signals and power rated components will be large surface or through hole.I was looking at my SDRPlay that uses around 01005 and figuring out its size if it was through hole. Would be big; like 8" X 8" to hold those parts on one board. Some day I will make a circuit with through hole and all the way down to 0201 like that SMD challenge board. What was I thinking giving away my B&W laser printer!

author: wraper
author_rank: Unknown
timestamp: August 21, 2018, 10:27:45 pm
content: Quote from: Beamin on August 21, 2018, 10:25:15 pm008004

author: Beamin
author_rank: Super Contributor
timestamp: August 21, 2018, 10:30:05 pm
content: I like how the parts get really sloppy down small. MrCarlson would go nuts to see such crooked parts.

author: boB
author_rank: Frequent Contributor
timestamp: August 21, 2018, 10:38:29 pm
content: Make sure you have a good pair of tweezers !boB

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 01:06:02 am
content: yea position it first with a microapplication of super glue then touch it with the smallest tip you got on both sides, the only problem is that the surface tension is really big.If you can pin it down with a long flat nose needle so it does not get dragged towards the iron that works too, its pretty easy if the PCB is made rightlike flatten a thin needle down on a diamond file so you can hold it at a 45 degree angle with a flat surface pressing the component into the PCB, then solder one side down, get a good vantage point and solder the other side down. Flux will help you alot.Also make a handle for your needle so you can hold it comfortably. Like press it into a plastic stick or glue it to something.You might wanna stick your board ontop of a ball of playdough or something to prevent deflectionin and popcorning when you do this operation because it can easily jump if you tension the board inside of a typical soldering vise. Position it with tweezers first.You can probobly do the smallest one there by hand but you would need to carefully make a tool to tension it and probobly make some kind of doodad to hold your tension rod in place with, I don't think you will manage that by hand.Also be sure to flame clean the needle before hand to get rid of any sticky oils and keep it polished to prevent the part from sticking to it. I would recommend using ceramic tweezers for positioning, and to keep a butane torch on hand so you can heat the tweezers to red hot for a full surface clean (let em cool obviously) before positioning, any kind of oil buildup will fuck you up and make the part stick to the tweezers and annoy the hell out of you.I managed to make a LED ringlight on veroboard with 0201 parts before IIRC, using the crappiest tools to wedge fluxed parts into molten flux blobs.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 01:14:32 am
content: Quote from: coppercone2 on August 22, 2018, 01:06:02 amSuperglue under SMT, are you crazy? Not only you won't be able to apply it without covering nearby pads of such small part (will cause soldering problems), it will also burn with really nasty fumes once heated. Not to say it's a little bit conductive.

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 01:16:49 am
content: I said microapplication. Like dip a fine needle into super glue and tap it on the part. It takes skill. I think I used the 'ultra thin' super glue for thisIf the board is crappy you can glue some thread to it using the same technique to make a little mound to put the part ontop of so that you don't need a big glob of glue (like building a little cribbing).I wonder if you can use wax actually. I won't lie, it smells awful and burns your eyes if you don't use ventilation. I use super glue for holding metal together during tac welding too, with gas no lessYou can build 3d terrain features with different consistences of super glue using fine needles to apply it. I have ultra thin (thinner then water), regular, gel and ultra gel. You can use baking soda dusting to prevent it from expanding into a puddle because it will cure extremely fast also.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 01:22:01 am
content: As of retaining component in place while soldering with iron. Apply a little bit of solder on one pad. Apply some flux (gel or liquid) place the part with tweezers. Solder end with solder applied. Then solder other end. No glue or other unnecessary crap and useless manipulations. Larger part on the video but process is the same.

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 01:23:17 am
content: I find the smallest of parts tend to like to move because of the flux boilingWhich tweezers do you use for 0201 parts? My best swanstroms seem too big, I did not have them when I was working with such fine parts.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 01:28:15 am
content: Quote from: coppercone2 on August 22, 2018, 01:16:49 am0201 footprint has around 0.3 mm in between of the pads. Reliably placing glue in that gap without it bleeding on the pads is not possible. If it won't bleed while you placing the pad, it will once you place a component on top. Also as I said you should keep superglue out of electronics as it's conductive. But when heated it no longer holds. And with such small part glue will overheat immediately.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 01:30:03 am
content: Quote from: coppercone2 on August 22, 2018, 01:23:17 amI have no problem holding 0201. With 01005 it's an issue though as part is smaller than ends of fine tweezers.

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 01:35:00 am
content: Quote from: wraper on August 22, 2018, 01:28:15 amyou can't really put glue on the part, I mean you make a kind of knife edge on the pcb area under it, like by brushing it with a wire that is pulled out of a high density cable (like flexible multimeter cable) to make a super glue mound, that you put the part ontop of, when its a bit wet.The bond is very weak. I mean it literarly like micro-3d printing a little tower with your hands, not a single application that would deform.36AWG is 0.1 mm for instanceYou kind of need to let the glue cure a tiny bit, depending on the initial consistancy, to be able to do a layer-raise wipe that does not spill out and contact the pads, under some magnificationMaybe I can take a picture to explain better, let me see if I can find a thin enough wire strand. I tend to avoid these parts anyway because they don't offer me any benefit. I have a transformer somewhere that was wound with incredibly thin wire which I used as a brush element.

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 02:01:30 am
content: Need a thinner wire to demonstrate the capability, this glue I have is spreading too much on me. If I find one I will update. Smallest I have is 0.12mm, too large, I can definatly file this overside bead down to the right dimension though.also helps if you get the wire work hardened. And you dip it in baking soda water to quickly harden it. I think the loctite gel control will do better, I only have the liquid control one. IIRC the ultra gel is too much. Then when you sculpt the mound you use the ultra-thin to paint it and to make the glue bond.Maybe I will try a wire brush bristle if I can find one small enough, from the dremel wheel perhaps

author: Brumby
author_rank: Unknown
timestamp: August 22, 2018, 02:32:10 am
content: Have done 0402 and I picked up some random 0201 to try my hand with them - but haven't gotten around to having a go with them yet.My biggest problem has been making sure they don't get lost. This silicon sand can disappear on even bare wooden floors.

author: coppercone2
author_rank: Super Contributor
timestamp: August 22, 2018, 02:41:28 am
content: I just got an interesting idea, I feel like an idiot doing what I was doing.So long the board is pretty clean and does not already have large parts on it, you might be able to dip a very thin wire thats long into the thinnest super glue, press it on top of the part across the dielectric, wire it down by twisting the wire over the entire board, solder, remove the wire, and optionally grind away the remaining super glue off the top of the part with your most fine file.Conceptually it seems easy to align and everything, especially if you stick the part down on some thing mushy (like the silicone tape that is used inside of plasma tv's to hold the screen. Since the wire is very long compared to the part dielectric width you can do hand adjustments to center it properly, if you hold it like a garrote. Huff and puff on the part when you make the right contact to solidify the glue a bit,.MMm you can do those bastard filters and capacitors this way that have a fucking two grounds, like x2ylike thisI also like using magnet wire to make near bundles for wire-wire joints, you interlock two wires so the fingers go into eachother, wrap it tight with magnet wire, flux it and solder it, and the magnet wire pulls right off and makes a nice tight fillet thats more compact then premade solder sleevesmaybe you can make something like those dental floss plastic things for flossing your teeth without having to use your hands too so you can just tension a part down. Hell this could be useful for QFN even.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 05:10:32 am
content: QuoteThis works great. If you put too little solder on the central pad, it can get stuck to the board and not center itself. If you're doing a lot at a time in a batch, you can try to get closer to the mark. But if you do the odd one here or there for a repair, I suggest the bigger the glob; the quicker the job. Too much solder is never a problem with QFN. As long as you have a microscope to view the surrounding pads/parts. Too little solder can waste a lot of time.Beamin: hand soldering with an iron is very easy. You're only limited by the fineness of your tweezers and your vision.The challenging part is the handling - getting the part from the tape onto the fluxed PCB. When you get down to that small a part, you need a very small pickup needle, and it will need frequent cleaning/replacement. And trying to pick them up with tweezers BEFORE you get them under the microscope and slathered in flux is just not a good use of your time. For every part you get on the board, you will blink 2 out of existence.There's no need for superglue. Any flux will do. The first time you touch them with tweezers or attempt to align them should be immediately followed by tacking with the iron. Why align with superglue, at all? Just wasted time.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 08:05:37 am
content: Quote from: KL27x on August 22, 2018, 05:10:32 amIt's not great at all, and he spends 10x more time than needed to solder QFN. If you solder as often as him, you should really have the feeling of right amount of solder on a center pad. Starting from 6th minute, torturing a single poor chip for another 6 minutes after old one was already removed,. He effin does the same even with tantallum polymer capacitors. Every time I watch, it's like "why are you doing all this crap, just apply a few times less solder, and don't bother doing all of this unnecessary nonsense." It's actually so simple just applying the right amount of solder and get the thing soldered properly on the first try and skip all of that rework with iron and reheating.

author: Rerouter
author_rank: Super Contributor
timestamp: August 22, 2018, 08:27:25 am
content: Pretty sure rossman does it on purpose now, he has made a number of callouts to us lot reacting to his solderingAs for 0201, yes defiantly can do by hand, I have even had to do 01005's after blowing them off an RF PCB i was doing rework on, All I can say to the people that made that layout is "your PCB package has courtyards for a reason!"I'm shortsighted, and have a very good focal range, but Even I pull out the desk magnifier with 0201's, as it just strains your eyes too quickly.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 10:22:38 am
content: QuoteIf you mean at the 7 minute mark, that is more or less what I would put on there. Or let's say that's the minimum I'd aim to put on there. Rather than buying super thin solderwire to solder hundreds of QFN, I spent awhile figuring out just how much solder I could glob on a QFN footprint and for it to still solder perfectly fine without requiring extra steps or making things more difficult. And it's a lot more than that.After you squish it down, the excess goes out to the outer pads, and the perfect amount of solder is left on the center pad, holding it from popping back up. Any excess solder or bridges on the outer pads gets wiped away with the next step, anyway, the way I do it.If Louis takes 10 minutes to change a chip, it's because he is fixing things, not assembling a pile of boards. But more importantly, it's because his videos are not about soldering or even fixing things. They're just a vessel for him to talk. That's his greatest gift. The man can talk.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 10:35:06 am
content: Quote from: KL27x on August 22, 2018, 10:22:38 amIt's certainly not a perfect amount of solder. QFN should stay a bit above the PCB, not completely down the bottom like after squeezing the solder. Soldering such chip would take me a minute (or 2 tops if I'm not in hurry), without all those extra manipulations, without multiple reheating causing stress, without multiple flux application and result would look nicer. And I would be 100% sure there are no shorts under the chip.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 10:36:28 am
content: Quote from: KL27x on August 22, 2018, 10:22:38 amNo offence, but I sometimes wonder if people read properly?That was clearly not his point.His point was just to give an example, not to judge the person about it and discus the reasons that are out of the subject.The example is about how it should NOT be done.Nothing more, nothing less.Soldering is about the flow, literally and figuratively speaking.I always compare it to paint or varnish, that also naturally "flows" to a nice smooth surface.Like it fills the caps automatically.Soldering is more or less the same.I see so many people trying to use it like some sort of glue (some other Youtuber in particular).Let it flow mon!

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 10:39:37 am
content: Quote from: wraper on August 22, 2018, 10:35:06 amI have worked with chips that are already done and fried after so many minutes of heating.I personally never get the extreme amount of extra flux people add.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 10:41:04 am
content: Quote from: b_force on August 22, 2018, 10:36:28 amI commented about Louis' soldering only because he was mentioned previously as example. Although he does a great job, he certainly is not a person who you should take as example for learning soldering. You won't learn how to solder properly and will develop bad habits.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 10:47:17 am
content: QuoteIt doesn't stick to the board off center, and that's all that matters to me. The squeeze out is nothing to worry over. No pins with tall shoulder for the solder to suck up into. Worrying about too much solder on the center pad when hot air reflowing is like worrying about snow in Miami.Taking too long, that's another matter, entirely. But getting people to watch how he can do just about anything, that is surely helpful for a lot of people.* I don't always agree when he gets overly opinionated on the specifics of how/why/what. As you have said, he has admitted many times his soldering is not great. But you wouldn't know he had said anything like that the 99% of the time he isn't saying it, lol.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 10:54:03 am
content: Quote from: KL27x on August 22, 2018, 10:47:17 amPlease tell me why would you do substandard soldering when you could do it up to spec with less time and effort spent? You could watch him to learn troubleshooting but for soldering look somewhere else. It's amazing how many people solder badly after being in business for decades when it would take only a few days to learn soldering properly under a good guidance.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 11:12:08 am
content: ^Anyone ever tell you you're a bit of a hot head?QuoteWhy would you call that substandard? Are you worried about mechanical or electrical connection? And have you done any failure testing? Have you actually measured the height of the solder joints of your QFN's after soldering? And with what equipment do you do that?

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 11:13:27 am
content: I have a very different opinion about the man in question, but let's not go there.It's very offtopic.I agree with wraper.With a proper technique you can easily solder small SMD parts by hand.But I believe even in something else.The main issue most people have is lack of patience.I have taught many interns to solder, and I can very clearly see the difference between guys who have patience and the once that don't.Even when using the same techniques

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 11:14:52 am
content: Quote from: KL27x on August 22, 2018, 11:12:08 amAn hot head?I would call it difference in culture.He is simply to the point.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 11:20:24 am
content: Quote from: KL27x on August 22, 2018, 11:12:08 amEven if we take out the quality of solder joins themselves, the thermal stress applied to the chip most likely exceeded the spec given in the datasheet. Also too thin solder means less stress relief for thermal cycling.

author: CJay
author_rank: Super Contributor
timestamp: August 22, 2018, 11:25:43 am
content: Quote from: wraper on August 22, 2018, 10:54:03 amThe bad soldering on so many Youtube videos makes me cringe, there are so few who can solder well.Quote from: b_force on August 22, 2018, 10:39:37 amFlux everywhere, there are some really skilled technicians who *flood* boards with flux and still make really bad solder joints (probably because of the excessive quantities of flux), it's really frustrating to watch because they insist it's necessary.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 11:32:34 am
content: Quote from: CJay on August 22, 2018, 11:25:43 amWhat I even understand less is that when you point this out about those "skilled technicians", people get all huffy puffy and telling you're being rude?

author: CJay
author_rank: Super Contributor
timestamp: August 22, 2018, 11:38:56 am
content: Quote from: b_force on August 22, 2018, 11:32:34 amI tend to believe those technicians (and they are skilled, just not at soldering) make people believe soldering well is way more difficult than it is, it does take practice and skill but soldering well is nowhere near as difficult as it's made out to be, just needs some training and patience.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 12:02:47 pm
content: I, FWIW, am not huffy nor puffy. Just curious.I figured, Wraper, you be thinking along the lines of thermal cycling. I concede this is not a concern I have experience with. I've never used QFN for high power parts. Just control circuitry. It's interesting information for sure.As for thermal stress of soldering, I am not sure what you mean. Or maybe you meant the 10 minutes of messing around... I admit I didn't watch that part. I just scrolled through the vid to see the center pad thing.QuoteIf I'm paid by the hour, I have all the patience in the world to do it however the boss wants. I've taught a few employees some tricks as an outside consultant, and this is the problem. They don't care how long it takes to do it "their way." Some things stick, some don't. The employee, especially the new ones, aren't the ones to know the failure rate or even the desired life cycle of the product. Or if the QFN is the weak link to any statistical significance to begin with. They have their way they can do without thinking, and it has got them thus far, and maybe just don't want to learn. I wouldn't want my employee to worry about thermal cycling unless I am worried about thermal cycling.The most experienced soldered I have known was a professional for many years. He brought his own Metcal to work. The only one at this particular company to use his own equipment. But man he was a turtle, and set in his ways. I wonder if he soldered for NASA.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 12:18:39 pm
content: Quote from: KL27x on August 22, 2018, 12:02:47 pmThat's not the type of patience I am talking about.I am talking about the lack of it. So the feel that people just want it done quickly.Not literally speaking, you can still be as quick and fast WITH patience.Thermal stress means that you will damage the part you're soldering by applying to much heat for to long.10 minutes of heating is an awful lot.Sometimes even solder pads and PCB tracks will get loose pretty quickly.I guess Louis may be lucky that Apple has decent quality boards.I know other boards (from good expensive brands) were pads will be gone and far already.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 12:22:48 pm
content: Quote from: KL27x on August 22, 2018, 12:02:47 pmMany parts explicitly say you can heat them up like 2 or 3 times maximum. What Louis have done is like running component through 4 reflow cycles. Yes it will work most of the time but a few components out of hundred or thousand may die and some others may be wounded thus reducing reliability over long term. I would be OK with that if there was some good justification for that but there is none. It's just more hassle with worse result.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 12:27:11 pm
content: Quote from: wraper on August 22, 2018, 12:22:48 pmWorse is even when your part looks and tests fine.But because you already thermally stressed it so much it has become some sort of ticking time bomb.I actually have experienced this with one of our suppliers.They soldered some opto-couplers a little to hot, worked fine in the factory but ALL of them died somewhere in the next two years.Obviously some parts are more prone to this than others.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 12:30:45 pm
content: QuoteOk, so the amount of solder isn't in question regarding this thermal stress, then? Thanks for your input. I wonder if Wraper agrees.QuoteFor surely, he knows the pain of replacing a broken board. And he knows how often a customer comes back with a problem within his warranty period. He probably hears from them beyond warranty, too. Everyone who cares about time and money solders for a specific purpose, not just to solder the best they possibly can. In some cases, the concerns you might get hung up on may not be the statistical weak link by a long shot, if even a concern to begin with.The reason I have learned to solder QFN this way was primarily because it was the most repeatable and efficient way for me to do it, and I am not paid by the hour. If there develops a problem, at least it should be consistent. Lucky me, the bulk of my QFN hand soldering was done a low temp part/board which will be obsolete within 10 years, anyway. I'll be glad to have learned about this thermal cycling issue at some point, I'm sure.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 12:42:44 pm
content: Quote from: KL27x on August 22, 2018, 12:30:45 pmBut it will affect strain when thermal cycling and warping the board. And not only solder joints themselves but also IC package. Is not some invulnerable fortress which does not care about external mechanical forces applied. Don't forget that QFN or MLCC caps don't have flexible leads to absorb mechanical strain. It's hard to quantify the effect of this, but it's better keep safe, especially when there is no additional effort.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 12:45:40 pm
content: Quote from: wraper on August 22, 2018, 12:42:44 pmIn simple words.Materials expand and contract with changes in temperature.This is no different for an IC

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 03:53:57 pm
content: So I watched the whole video. At first I thought it was totally normal. Then I see where he repeated the entire process on the already soldered chip. That was unexpected.I've seen him solder an MLCC by iron, then go over it with hot air. I thought maybe it was to relieve stress of uneven heat from the iron. I thought he was going to stop after the second hot air reflow of the QFN. But he went even more banshee with the iron, afterwards. Now I wonder maybe he just likes fiddling with things to make a longer video.But watching him do this reminds me of the practicality of squishing the part. When the flux starts to boil, the QFN just dances around and skitters off the pads. What I do is pin it down the whole while it is heating. And just as soon as I feel it flow and squish, I let go the tweezers. It bounces back enough to self center. Sometimes it might snap to the wrong pads, but a nudge will put it back on track and it'll snap to. It's not a starved joint. If this is substandard, it is at least consistent and not fiddly/PITA.I just wonder maybe you guys end up relying so much on feel and sight on the amount of solder you put on there, that this might not be as consistent as you think. And how do you guys doing it "super standard" get the part to stand still or at least keep it mostly over the pads until it flows? While trying to corral the wild phillie, you are juggling the heating and perhaps not able to focus so much on even and consistent ramp/heating and minimizing the thermal stress? Louis backs off the heat gun while reigning it back in, for example. Just seems such a pain if that's the only proper way.

author: KL27x
author_rank: Super Contributor
timestamp: August 22, 2018, 04:28:07 pm
content: QuoteAnd in some cases I think people make it out to be way more important than it is. While I'm way off topic, let me share an example.It is a cliche, at this point, when tearing down a chinese product on Youtube to comment on bad soldering like it's hilariously terrible. Take the "power fist reciprocating saw" review by AvE. (I know he's a dirty word to some of you's.) But he finds the soldering hilariously bad; makes his jokes. Then he proceeds to crack some aluminum parts in his vice, put the thing back together, and SURPRISE it fails an inch into the first cut when the aluminum castings fail. Damn the terrible soldering, eh?

author: @rt
author_rank: Super Contributor
timestamp: August 22, 2018, 04:32:37 pm
content: Quote from: mdszy on August 21, 2018, 07:45:40 pmI want one!Where can it be got?

author: james_s
author_rank: Super Contributor
timestamp: August 22, 2018, 05:19:45 pm
content: I frequently hand solder 0603 parts without trouble and I suspect 0402 wouldn't be too hard. I accidentally ordered a 0201 part a couple times and the problem with those is if you breath too hard you will blow them around the board. If you can find something to hold it down so it doesn't stick to the soldering iron then it's feasible to hand solder but I think I would use reflow if possible.

author: ju1ce
author_rank: Regular Contributor
timestamp: August 22, 2018, 05:38:25 pm
content: These seem to be available in Tindie if you look for "SMD Challenge", however it looks like they are sold out (there were plenty in stock this morning so I guess eevblog has contributed to their success).

author: Beamin
author_rank: Super Contributor
timestamp: August 22, 2018, 10:04:14 pm
content: Quote from: wraper on August 22, 2018, 01:14:32 amThat's what I thought . I tried this once with that really thin superglue you buy for model airplanes. The stuff is almost as thin as water and has a nasty habit of wicking or running down the part you holding gluing your hands to it. I tried to put it in an insulin syringe but its too thick for those needles. Even testosterone since it's an oil wont pass through those needles. So I got a 25 or 22 ga needle but that is almost too big for SMD getting one pad covered in glue making an insulator. Depending on the humidity the super glue will last a day in the needle before gluing the plunger to the side or not even a few minutes in the summer time. Having central AC doesn't seem to make a difference. Is there a better glue? Using flux as glue seems to be the best but it doesn't always work. You really don't need the crazy strength and durability of super glue just a few minutes working time.I was also thinking putting UV curing glue in a needle if its thin enough then after you have everything perfect shining the UV light on one side of the part curing just a small amount of the glue and wiping the rest off with alcohol. Harbor fraught sells blacklight/UV LED flash lights for cheap. I remember buying a 70.00$ snap on UV flash light to find leaks in AC systems then taking it back when I found it was super dim and you could buy the same thing online for 1/10th the price. And it was made in china. That company really is using its past reputation to sell over priced junk.

author: wraper
author_rank: Unknown
timestamp: August 22, 2018, 10:39:06 pm
content: Glue for SMT assembly is only used when wave soldering or holding heavy parts upside down during second pass of reflow soldering. Still I don't think anyone uses wave soldering for 0201. If you glue for hand soldering, there is something wrong with your soldering skill and you need to learn doing it properly. Anyway I would suggest getting hot air if you don't have one. These days it's a must, without it you cannot solder many types of components at all.

author: b_force
author_rank: Super Contributor
timestamp: August 22, 2018, 10:49:14 pm
content: Super glue and heat.Oh boy, you will have such a great evening.Don't tell the DEA.

author: james_s
author_rank: Super Contributor
timestamp: August 22, 2018, 10:53:37 pm
content: I've made the mistake of getting superglue hot before. It really burns the sinuses and eyes, not a good idea! It's a neat handy trick if you want to visualize latent fingerprints on something that is not easily dusted though, look up "superglue fuming" if you're curious.

author: coppercone2
author_rank: Super Contributor
timestamp: September 02, 2018, 08:19:39 pm
content: If you are making a right angle with welding and dont have clamps a dash of super glue works but it smells bador if something is upsidedown or in an annoying location.obviously the quality will suffer compared to good clamping but it will work fine if you adapt for the weakened joint

author: Beamin
author_rank: Super Contributor
timestamp: September 13, 2018, 06:38:12 am
content: Quote from: ju1ce on August 22, 2018, 05:38:25 pmThey owe me a royalty. I have done that with youtube channels too where they got that head start just enough to snowball the algorithm. The youtube algorithm is getting really bad with just recommending huge channels and not the little ones. Linus tech tips comes up every click and I barely watch it.

author: b_force
author_rank: Super Contributor
timestamp: September 13, 2018, 10:24:50 am
content: Quote from: Beamin on September 13, 2018, 06:38:12 amI think you can exclude certain words similar to Google search.So like: "PCB design -EEVblog" won't show Dave's videosBut yeah YouTube works very buggy.Even with history turned off it still keeps track of what you watch and will always show these relevant results first

author: generic_username
author_rank: Regular Contributor
timestamp: September 13, 2018, 11:26:22 am
content: At my last job we ran tests alot so we had to solder some small componentes here and there for different results, 0402 were common as they needed to be at least 50V but when we had to change stuff near the chips it was usually 0201 and in special cases 01005 for the later without a microscope is horror.

author: Rerouter
author_rank: Super Contributor
timestamp: September 13, 2018, 12:13:32 pm
content: I feel the microscope is never the issue on these small parts, more how good your tweezers are, and how much caffeine you have had in the last hour,Then again I have 20/15 vision, which may help things.

author: generic_username
author_rank: Regular Contributor
timestamp: September 13, 2018, 12:26:01 pm
content: Yes good tweezers are a must, altough you have to clean them a lot, it's a pain in the butt if there's flux on the tips.