An alternative method for soldering through-hole components - Page 1
Forum section: electronics / projects

author: intabits
author_rank: Frequent Contributor
timestamp: March 14, 2019, 07:49:45 am
content: Prompted by seeing one too many YouTube videos that display poor soldering technique of leaded through-hole parts, I've made avideo describing the way I was taught to solder them.I believe this method to be far superior to what I saw in those other videos:-* Faster due to less tool handling, and streamlined operations.* Better contact between component lead and PCB copper.* No exposed cut lead that can rust or oxidize.* A smoother result, with no sharp points to damage wires or other nearby parts.* A less stressed solder joint, improving reliability.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 14, 2019, 08:36:34 am
content: No no, that's not a good idea, and you don't know because you can't see it if the solder is good. Even if it's good, it's worse than the normal way because the soldered surface is much less, only a tiny spot. I don't like it.

author: Phoenix
author_rank: Frequent Contributor
timestamp: March 14, 2019, 09:34:48 am
content: This method might be OK for single layer (not plated holes) for resistors and capacitors. But from what I can see getting a good quality join is no easier than keeping straight leads. It also looks like with the leads folded it might be harder to get 100% coverage of the hole, especiallyIMO better off focusing on the basic ideas like properly wet joins, good fillet, correct amount of solder, solder heat bridges and where to apply the iron and the solder. Rather than pedantry like exposed tips of cut components.Sent from my G8441 using Tapatalk

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: March 14, 2019, 09:43:26 am
content: In old NASA stds (military) soldering it was preferable this way. Fit component bend leg to lay flat on the pad/trace then cut and solder. But the pads and traces were larger in those days allowing the leg to form a nice solder fillet. These days boards pads and traces are in general much smaller. That said I rarely saw a PCB with components fitted like this.I understand what your saying about ingress of corrosion etc. Usually I conformal spray or brush coat after inspection and cleaning. It’s be more beneficial if users spent more time inspecting their solder work post cleaning under a good eye loupe or camera. The amount of crap joins I’ve done or found this was is incredible.All that said I usually solder and cut enduring the cut is above the solder fillet.Edit: if you have to remove a component that has had its legs flat on the pad/traces..... you’ll curse the day.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 14, 2019, 10:36:23 am
content: Quote from: wasyoungonce on March 14, 2019, 09:43:26 amHear, hear!+1

author: MWP
author_rank: Contributor
timestamp: March 14, 2019, 03:39:19 pm
content: Quote from: GeorgeOfTheJungle on March 14, 2019, 08:36:34 amYup, not a fan for the same reasons.If the lead was a little dirty, you wouldn't be able to tell if the solder had not "wet" onto the lead properly.This method will be prone to far more soldering failures, and they will be more difficult to visually diagnose.

author: kony
author_rank: Regular Contributor
timestamp: March 14, 2019, 04:50:19 pm
content: IPC-A-610. Had you seen it yet?

author: MaTkEOxjC
author_rank: Contributor
timestamp: March 14, 2019, 05:16:56 pm
content: The NASA hat their soldering standard online available:https://workmanship.nasa.gov/lib/insp/2%20books/frameset.htmlI wouldn't sick strictly to them, but if you want reliability this could probably give you a good overview.Section: 6.01, Page: 3 shows that cut leads (exposed copper) is acceptable for them. S6.0.1P12 shows that the pad still should be fully tinned.Also, you will probably hate yourself when you have to remove a component again ^^"

author: tooki
author_rank: Super Contributor
timestamp: March 14, 2019, 07:18:41 pm
content: Quote from: intabits on March 14, 2019, 07:49:45 amWhile there are some advantages to trimming and clinching before soldering (which is why it’s used), as soon as I read “I’ve made a video...”, I groaned and thought “Oh boy, not again”, because soldering is something where there are far, far, far too many bad videos, despite the fact that excellent ones already exist.As others have said, the huge disadvantage to clinching is that it makes repairfarmore difficult. It’s really only in high-reliability applications that this is ever really necessary. But moreover, I very much disapprove of how you title your video “how to solder through-hole partsproperly”, that is, implying that other ways are improper, and that in the video, you refer to the standard way as “the bad way”, which it isn’t. Combined with the wildly excessive length, and the poor video quality, and it’s... well... just another soldering video that adds nothing compared to the videos from PACE Worldwide, which IMHO remain the gold standard. You should check them out, especially since they do go into clinching.

author: Dave
author_rank: Super Contributor
timestamp: March 14, 2019, 09:14:09 pm
content: You keep repeating in your video that component leads are made of steel and are prone to rusting.They are actually made of copper (with a tinned surface). Exposed copper will form an oxide layer which is pretty much inert.

author: tooki
author_rank: Super Contributor
timestamp: March 14, 2019, 09:29:18 pm
content: Many cheap components use tinned steel leads. Take a magnet to them sometime, you'll be surprised. Similarly, see how some rust...

author: MarkF
author_rank: Super Contributor
timestamp: March 14, 2019, 09:52:48 pm
content: Quote from: wasyoungonce on March 14, 2019, 09:43:26 am

author: soldar
author_rank: Super Contributor
timestamp: March 14, 2019, 09:59:51 pm
content: Quote from: tooki on March 14, 2019, 07:18:41 pmThere are too many bad videos and besides being bad for all sorts of reasons they are all way too long and can be reduced in length to one fifth and they would gain in quality a lot. Some people have trouble getting to the point.

author: wasyoungonce
author_rank: Frequent Contributor
timestamp: March 14, 2019, 10:22:10 pm
content: Marks video is pretty good. He cleaned the solder (with kippex). Solder oxidises quickly and over weeks months really needs a good clean. I use “chux cloths” ( I can wash them) with isopropyl. Always spend quite a time in prep and cleaning....as it should. Being self critical is good but not anal. Reworking joins to make them perfect isn’t the best thing to do wrt PCB pads and substrate.He did use a practice board...I still had some old military practice boards they have changed a lot. It’s always a good idea to start every job with some practice joints first .... to iron out the work flow bugs.What ever way you do it....”clean everything” prior during and after. Then inspect.

author: austfox
author_rank: Regular Contributor
timestamp: March 14, 2019, 11:19:58 pm
content: Wow, 11 minutes in and he’s still on the first resistor. He should be finished that board by 2021.

author: David Hess
author_rank: Super Contributor
timestamp: March 15, 2019, 01:13:17 am
content: Quote from: tooki on March 14, 2019, 09:29:18 pmKovar and alloy 42 are also magnetic.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2019, 02:18:01 am
content: Quote from: David Hess on March 15, 2019, 01:13:17 amSure, but how often is one soldering those to a PCB??

author: David Hess
author_rank: Super Contributor
timestamp: March 15, 2019, 02:57:19 am
content: Quote from: tooki on March 15, 2019, 02:18:01 amEver solder a 1N4148 diode or a film resistor?Axial power diodes use pure copper leads for lower thermal resistance even in glass packages.The only time I have run across steel leads which rusted is with cheap power resistors.

author: MarkF
author_rank: Super Contributor
timestamp: March 15, 2019, 03:07:17 am
content: Quote from: austfox on March 14, 2019, 11:19:58 pmWe now know why it costs so much to send anything into space. Of course, repairs are pretty much impossible.There are a few other NASA soldering videos if anyone is interested.

author: intabits
author_rank: Frequent Contributor
timestamp: March 15, 2019, 03:51:59 am
content: Of course I expected my video to elicit some negative comments, but I was surprised to see almost *only* negative comments.Surprised, because this is a good method, and one that I see no negative downsides to.The advantages I mention (assembly speed, better contact area, smooth result, protection from oxidation, reduced shock stress), are all true.Some comments indicate that I may not have gotten my point across clearly, for example that the lead barely protrudes past the hole and/or that the lead is buried under a blob of solder and thus good contact with the solder cannot be assured. No, there is ample lead exposed to the solder, and an observable solder fillet, indicating good wetting, is formed:-On the subject of removability, the video shows how easily I removed the resistors soldered in what I termed the "bad way". Not to mention, the part being removed is likely suspect anyway, and causing damage to remove it (if required) should not be a problem, especially for cheap parts like resistors.I concede that the video title may be somewhat misleading and presumptuous (though not actually incorrect) and will change it to "An alternative method for soldering through-hole components". (and the subject/title of this thread also)To the criticisms relating to the more general aspects of video production (length, quality, etc), I say "Let he who makes perfect YouTube videos cast the first..."The PACE soldering videos mentioned above are indeed excellent. In places their examples have clinched leads as I advocate, though I cut them shorter than they show (which would make removal easier).And finally, I say "don't knock it 'till you've tried it".Almost everyone will have a never-to-be-used PCB lying around, and be able to sacrifice a dozen resistors for science.Please try out what I've described, and see if I'm full of crap...

author: bsfeechannel
author_rank: Super Contributor
timestamp: March 15, 2019, 05:11:06 am
content: I'll give your method a try with my next through-hole board. However, it would be interesting to see a video about desoldering and removing those parts.

author: Kasper
author_rank: Frequent Contributor
timestamp: March 15, 2019, 06:20:37 am
content: Thats how we did it in avionics. Cinch, bend and snip in one motion. Its not much harder to pull them out for repair. This warrants about 30 seconds of video.We were also taught to heat each joint for atleast a few seconds and to not use so much solder that you can't easily discern each component / lead. Your video along with many others has room for improvement in those areas.

author: GeorgeOfTheJungle
author_rank: Super Contributor
timestamp: March 15, 2019, 08:52:45 am
content: Quote from: MarkF on March 14, 2019, 09:52:48 pmLOL there are so many things wrong in this video I don't even know where to start. And the biggest problem is that this guy is... a teacher in a faculty? In whose hands do our poor sons end up these days? Just imagine how soaking wet one's got to have the sponge to say "when the tip touches the sponge the temperature drops".

author: vk6zgo
author_rank: Super Contributor
timestamp: March 15, 2019, 09:42:36 am
content: Both of the High Reliability Hand Soldering courses I did---- Telecom Australia back in the '70s, & TAFE in the '90s, reiterated that for normal solder through hole joints on PCBs, it was best practice to push the leads through, put a very slight "kink" in them to stop them falling out, cut the leads off to a standard level, then make the joint, being certain to place a little "hat" of solder on the end of the lead, to prevent oxidation.We were also taught "clinched" construction, with the warning that it was only necessary for largish components in situations subject to vibration, which was fairly uncommon.What both courses pushed was absolute cleanliness of components & solder to make the best quality joints.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2019, 11:33:01 am
content: Quote from: intabits on March 15, 2019, 03:51:59 amWell, EEVblog (and its forums) is famous for blunt honesty.Quote from: intabits on March 15, 2019, 03:51:59 amBut therearedownsides.Quote from: intabits on March 15, 2019, 03:51:59 amSpeed? Debatable. If you really care about assembly speed, you buy those special pliers that cut and clinch the lead in a single squeeze.Smoothness? Yes, it's smoother, but what's the advantage of this? I can only see this mattering in wearables, where cut ends snag on fabric. In a typical electronics application where the PCB is in a housing, it's totally irrelevant.Protection from oxidation? Absolutely irrelevant. If your board needs protection from oxidation of the cut lead ends, it needs protection of other areas, too, in which case you use proper protection like conformal coating.Reduced shock stress? If you're using proper, sharp tools, this really is a non-issue.In the video, you also keep mentioning copper-to-copper contact, as if solder somehow produced so much resistance as to matter. It doesn't. If it did, then millions (billions?) of devices that use DIP ICs would be malfunctioning, since DIP ICs are not normally clinched in mass production (in contrast with things like resistors, whose leads are normally cut and clinched by automatic inserters).Quote from: intabits on March 15, 2019, 03:51:59 amYour joints would fail IPC inspection because the component lead is not identifiable in the solder mound. It should be a meniscus, but leaving the lead shape visible.Quote from: intabits on March 15, 2019, 03:51:59 amIt's not about damage to the component, normally. It's the risk of PCB damage. With a resistor it's easy to get around, but what if you've clinched the leads on, say, a large electrolytic capacitor? You cannot snip the leads before desoldering, since they're hidden. So you must desolder first, and then while the solder is molten, pry up the clinched leads. Such mechanical stress on a hot trace is riskier, since the bond strength of trace to PCB is reduced while hot.Quote from: intabits on March 15, 2019, 03:51:59 amNo, it IS incorrect to imply that the standard method is "bad" and "poor". And the new title is differently wrong, insofar as it's not an "alternative" method — we've already demonstrated to you that clinching leads is an established method.Quote from: intabits on March 15, 2019, 03:51:59 amAh yes, the classic "well let's see you do it better!" retort… Me, I haven't bothered making any soldering videos because even if I had the equipment for and experience in video production, I couldn't exceed what PACE has already done.But also, your video is 15 minutes long, but could be edited down to probably 3. Meanwhile, it doesn't cover so many other important steps in soldering, such that it can't by any stretch of the imagination be considered a tutorial on soldering THT. It's merely a video about lead clinching. In 15 minutes, one could actually cover a lot. But again, why bother, when PACE has already done it so well?Quote from: intabits on March 15, 2019, 03:51:59 amSo then your method is actually one of combining the downsides of both standard methods? Either don't clinch, or do it properly (since the only real advantage is one of vibration resistance for high reliability in high-vibration environments).Quote from: intabits on March 15, 2019, 03:51:59 amI think it's rather presumptuous of you to assume that wehaven'tever tried it.Your attitude is one of "look at me, I know the one true way, nobody else does it like this but I know better, and everyone else would see the light if only they'd follow my lead", when in fact it's not secret knowledge, it's an established way that is used in some situations, but also isn't a magic panacea.

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2019, 11:38:30 am
content: Quote from: GeorgeOfTheJungle on March 15, 2019, 08:52:45 amThey're teaching to NASA standards, which were designed for high reliability. So… sorry, gonna believe them more than you.As for tip temperature dropping when touching the sponge: when lead-free soldering came about, the soldering equipment vendors all studied why it is that their existing tip designs failed so much more quickly when doing lead-free. And one reason (not the only one) is the thermal shock of touching the damp sponge. At the higher lead-free temps, the shock caused micro-cracking in the plating, allowing solder to touch the copper core material, dissolving it away. So this isn't an imagined problem, it's based on actual scientific study. (The solution is the brass wool we now use. That and thicker plating on the tips.)

author: tooki
author_rank: Super Contributor
timestamp: March 15, 2019, 02:17:17 pm
content: Quote from: David Hess on March 15, 2019, 02:57:19 amD’oh! Yes, diodes. Totally slipped my mind. When I think of glass, I immediately think of light bulbs and neons and the like. But you’re right of course!!

author: wraper
author_rank: Unknown
timestamp: March 15, 2019, 02:26:25 pm
content: Electrolytic caps often have iron leads.

author: soldar
author_rank: Super Contributor
timestamp: March 15, 2019, 02:44:02 pm
content: Quote from: wraper on March 15, 2019, 02:26:25 pmI believe they are discussing making them of plastic.

author: wraper
author_rank: Unknown
timestamp: March 15, 2019, 02:52:13 pm
content: Quote from: soldar on March 15, 2019, 02:44:02 pmBGA sometimes have metal plated plastic balls.

author: Kasper
author_rank: Frequent Contributor
timestamp: March 15, 2019, 03:20:50 pm
content: Quote from: tooki on March 15, 2019, 11:33:01 am"Copper to copper" contact is more about reliability than resistance. If solder cracks there is more chance of maintaining electrical connection if the lead is touching the pad. There is also less chance of solder cracking if mechanical stresses go directly from lead to PCB without going through the solder.

author: wraper
author_rank: Unknown
timestamp: March 15, 2019, 03:26:16 pm
content: Bending leads work well on single layer boards, it really increases reliability. I've seen a lot of those with cracked solder joints. If lead was bent, then crack in solder joint will be only partial if it happens. On boards with plated through holes, does not make much difference. BTW bending leads is a very common practice in modern SMPS which still use TH components a lot.http://www.versatecsolutions.com/samples%20pc%20boards.shtmlhttps://youtu.be/mbuPQ_Doq0A

author: donmr
author_rank: Regular Contributor
timestamp: March 15, 2019, 03:45:13 pm
content: Quote from: tooki on March 14, 2019, 09:29:18 pmIf you care about reliability then don't use cheap parts.

author: joeqsmith
author_rank: Super Contributor
timestamp: March 15, 2019, 05:08:42 pm
content: When we were using TH, leads were always processed like this. Even the semi-automatic and manual machines would use the same process.I made a video some time back showing my Eraser.https://youtu.be/DknvtBaK9lc

author: Shock
author_rank: Super Contributor
timestamp: March 15, 2019, 05:41:36 pm
content: As mentioned the method is called "clinching" and has been around forever. Here is Paces guide for component soldering, with an appropriate sized tip and time spent on each joint. The only "proper" way is the standard you are working to, which IPC covers comprehensively (more than I can explain below) in IPC-A-610 and IPC J-STD-001.Put simply, terminations should be either straight through, partially clinched, or fully clinched. Terminations in unsupported holes should be clinched at least 45 degrees. Lead trimming after soldering is acceptable as long as the solder connection is not degraded and either a reflow or inspection has been performed.They sell PCB holders with arms for convenient component holding, or whatever works best as long as it doesn't stress or damage the component or joint.

author: soldar
author_rank: Super Contributor
timestamp: March 16, 2019, 11:37:36 am
content: Regarding soldering techniques they have all been invented long time ago and, let's get real, it is not the same to be soldering in a clean room boards that will go on a satellite payload than a quick and dirty repair on a sprinkler control which is inherently unreliable anyway and you can repair every year. I have done plenty of soldering which is nothing to be proud of but it was quick and sufficient for the intended repair.What is important is to understand what factors lead to good soldering and what factors can lead to problems and why. Then a trained and experienced operator can decide what is best in each case.Regarding the making of Youtube videos, there are two considerations, content and presentation and both better be pretty good unless one is so outstanding that the other does not matter. If you find and post a video of president Kennedy getting shot we will probably forgive the unstable and shaky images. On the other hand, if you have a perfectly choreographed show of cheerleaders bouncing their tootsies around I am not going to complain that I did not learn anything substantial from that video.Some people think "Oh, my baby is so cute, let the world see how cute my baby is!". Those are the same people who think their farts have a very pleasant smell.Youtube videos have become very competitive and need to have both quality content and editing. I think people do not realize how much work goes into making successful Youtube videos. TakeThis Old Tonyfor instance. His videos have high quality content but are very funny, well scripted, well edited. Normally it would take a team of people to produce that kind of quality.A lot of Youtubers just let the camera roll while they are doing something. "How to build a workbench!" and you see 45 minutes of a guy using a table saw and other tools from which you learn nothing because you already know how to use those tools. Some basic drawings, diagrams and plans tell you much more than watching the guy at work.Have a basic script which is as short as possible while getting in everything indispensable. And then cut it in half.