soldering 101 questions - Page 1
Forum section: electronics / beginners

author: zerohimself
author_rank: Contributor
timestamp: March 01, 2012, 09:53:44 am
content: Ok, Hi everyone, I am so glad I found this forum!! I got some basic soldering questions I need to know answers to! I'll give you a little history first. I have a little experience soldering, but only with 15-30 el cheapo irons from RS. Once or twice the soldering worked out the way it has in the videos I have watched. 90% of the time, I get bad joints(or can't even get the solder to melt before I get damage to the PCB!!!!) I am in the PC/smartDevice repair field, and I need to be able to do stuff like fix DC/usb/vga jacks, and fix other common problems like BGA reflows(and maybe eventually do reballs) on motherboards and graphics cards. --- anyway, I finally gave up on my cheap tools, and ordered a X-tronic 4040http://www.amazon.com/X-TRONIC-MODEL-4040-Digital-Soldering/dp/B003TC8EQS/ref=sr_1_1?ie=UTF8&qid=1330594750&sr=8-1. Figured after reading several reviews this might be a decent enough tool to start with(I hope it is ;-). But I have some general questions that I have tried to search, and can't find consistent answers to.here goes:1. how do I properly tin and care for my new more quality Iron and tips? **everyone seems to have a different story about this one; and my last iron, it did not seem possible to tin(radio shack..), So I am a little concerned about how to properly do this**2. what temp should I solder different things at(with the iron)3. what temp should I solder things at (with the hot air) and how close should I keep the nozzle?4. how about desoldering temps with both tools?5. what temps should I attempt a reflow(more specifically a PS3/xbox GPU - yes I understand I could damage it very easily) at?6. are there any other good tutorials out there?(half the ones I saw, were poorly trained people showing how to do it their way; not the correct way)7. How about components... like that solder and wick I got from radioshack - are those good enough?I have watched days of videos on youtube; including dave's soldering tutorials, but I am trying to learn before I get my new toy in the mail, as I want to do things properly and now destroy my tools in the process. I need some basic guidance.. Thank you in advance

author: Rerouter
author_rank: Super Contributor
timestamp: March 01, 2012, 10:15:33 am
content: just to stick to my area, look out for goot brand wick, its sold at jaycar's, not sure about radio shack, but the smaller stuff works like a dream,although not neccesary due to the hot air, if you have a sensitive QFP or similar, chip-quick like low melting point solder can be handy to lift the chip without exceeding 100 degrees.for general smd stuff, such as passives, transistors and diodes, i tend to use 350 C, 60/40 solder. but as you continue you will get a better grasp on what works best,also, i presume this is all lead free for you, which is harder to do, and will leave that to others to help with,

author: zerohimself
author_rank: Contributor
timestamp: March 01, 2012, 10:28:20 am
content: 60/40 and 63/37 --- I would hope that they are not lead free ;-) I've tried to be as prepared as I can and do as much research as I can, but these are just some things I have trouble find answers to. The video for chipquick was pretty impressive! Got that and some solder paste on my next order from amazon.

author: Rerouter
author_rank: Super Contributor
timestamp: March 01, 2012, 10:49:17 am
content: 60/40 is leaded, the numbers are the ratio between lead and tin content,also as another thing, for smd stuff, a good flux pen is handy, for some of the worser off boards, and for rework, it just aids the solders own internal flux core at cleaning up a joint, (flux strips oxidisation of most metalic surfaces, rosin is a common type)

author: zerohimself
author_rank: Contributor
timestamp: March 01, 2012, 10:55:45 am
content: I got the liquid no-clean with a syringe, I'll add the pen to the next order too ;-OI got a feeling this is just going to take a week or so of playing with some of the old boards I have to get the answers I want, I need to know mostly about the tinning my iron part(hope it works out better than it did with the cheap iron!!).. can't find any consistent answers for it. The rest I can probably learn on my own with a bunch of practice

author: IanB
author_rank: Super Contributor
timestamp: March 01, 2012, 02:59:27 pm
content: Tinning the iron before each use is essential.Some irons may arrive new with some kind of coating on the tip that stops the solder sticking. If so you should clean the cold tip with a cloth and some cleaning solvent like IPA or alcohol, then after it dries plug the iron in and tin the tip with some of the "tip tinning and cleaning compound" that comes in small tins.When you make a joint heat is conducted from the iron to the joint through a film of wet solder. It will be impossible to do well unless this film of solder exists. A dry iron won't heat a dry joint.So before each joint you should wipe the tip on a the damp sponge to make it shiny, put a tiny fresh bit of solder on the tip to wet it, then touch the tip to the parts to be soldered. Almost immediately add more solder between the joint and the iron so that it touches and conducts more heat to the joint. Wait a second or two until the solder flows smoothly over and into the joint (it will get "sucked in" if it has worked properly), then remove the iron. It never hurts to add a bit of additional flux to the joint before soldering it. This also helps to conduct heat from the iron and helps the solder to flow over and into to the joint.

author: zerohimself
author_rank: Contributor
timestamp: March 01, 2012, 07:28:38 pm
content: @Dave.S & @IanB -- Thank you soo much!!!I love this forum already!!The 4040 got here today(and yes I am in the states..)!! unfortanetly I didn't net my solder cleaner dome, flux, and a few other items I'm waiting on... Well I do have some of that tip cleaner and tinning stuff, and I got a box full of old boards, and some flux paste... hmm, wait one second.... I'll be right back.... I promise

author: The_Penguin
author_rank: Regular Contributor
timestamp: March 03, 2012, 03:19:55 pm
content: I was on a training course a long time ago and the instructor did a bit on soldering. Why, I don't know. Anyone who couldn't solder well should NOT have been repairing this gear...Anyway this guy said you absolutely HAD to cut the end of the solder off before every joint, so the flux could get out. He actually did a video on it, and sure enough before every joint he picked up his side-cutters and snipped off the end of the solder.Seriously.

author: David Aurora
author_rank: Frequent Contributor
timestamp: March 03, 2012, 05:08:47 pm
content: My 2 cents...1. Whenever I'm done soldering for the day I'll clean off the tip (usually just with the wet sponge in my stand, occasionally with one of those metallic ball thingys if it needs it), then drop the temperature right down to just above the solder's melting point. Once the temperature is down I'll melt on a bit of solder and turn it off. Seems to work fine.2. It varies. Sometimes it seems better to go real hot real quick, other times it seems wiser to keep it a bit cooler and take the extra couple of seconds. Depends on the tip, the part, the PCB, etc. I think you just get a feel for it after a while.3. See above. You really just have to dive in and do it on some scrap parts for practice. Especially when there's really small components involved. Like if you're soldering a high pin count chip right next to some 0402's, you're going to have to be more careful with fan speed unless you want to resolder the whole area.4. See above. Try it. Feel it out. It's going to vary depending on tip, fan speed, pad/part sizes etc.5. No idea, I haven't tried it.6. Dave's series was pretty cool. I was already fine with soldering before I saw it so I didn't really pick up anything groundbreaking from memory, but it did reaffirm my own methods which was nice to know seeing as he's got years more experience than me. And if I had seen it when I first started soldering it would've saved me a lot of trial and error haha7. This one is where I did really get a gem of knowledge from that series. You absolutely do get what you pay for with things like solder wick. For ages I thought solder wick was completely fucking useless and annoying based on past experience with no name stuff. Tried the solder sucker type tools and preferred them, but still wasn't happy and I wanted a vacuum desoldering gun. But on Dave's recommendation in his tutorial I tried some decent quality wick and holy shit it makes a difference. Suddenly I could desolder things lightning fast and very cleanly with less effort than before. Also, I saw the name Goot pop up here. I ran out of the Multicore stuff I've been using the other day and popped down to Jaycar for the Goot stuff because I needed it immediately and Jaycar is walking distance from me. And yeah, it's usable, and cheap, but it didn't feel remotely as nice to work with as the Multicore stuff.

author: ciccio
author_rank: Frequent Contributor
timestamp: March 03, 2012, 05:18:47 pm
content: Quote from: The_Penguin on March 03, 2012, 03:19:55 pmI've seen the video... this guy could be the slowest PCB soldering technician in the world (please understand me, I'm not discussing it's professional qualification, only this point).I'm into soldering since high school (1967).I'm working in electronics since then, and at those times I've seen professional soldering maybe millions of joints, and nobody has never done this.Maybe it comes from some obscure MIL standard, but it a waste of time (a lot of time) and solder.As soon as the tip and the solder come in contact, the flux will escape from the wire and do it's work.Best regards.

author: Tony R
author_rank: Regular Contributor
timestamp: March 04, 2012, 03:44:10 am
content: Quote from: zerohimself on March 01, 2012, 09:53:44 amevery tip will have a rated temp, do not exceed this. To tin you place a small amount of solder on the tip, I then wipe it off and tin it again. The first time is to remove dirt and debris, the second is to help transfer heat. Also make sure you tin it before you put it away, the solder on the tip will keep it from corroding.Quote from: zerohimself on March 01, 2012, 09:53:44 amWhatever the soldering tip, the solder, and the component is rated for. Most of the time it is found in the data sheet. I go for as high of a temp that I can and work quickly to minimize the time the chip is under that heat.Quote from: zerohimself on March 01, 2012, 09:53:44 amOnce again whatever temp they are rated for, this is where an inferred thermometer comes in handy. How close to keep it depends on how hot the chip gets.Quote from: zerohimself on March 01, 2012, 09:53:44 amOnce again whatever the part is rated for if you wish to save the part. So same as before, maybe a little less because it is probably going to be under that heat for longer.Quote from: zerohimself on March 01, 2012, 09:53:44 am... I feel like a broken record, whatever the parts are rated for... most parts have a reflow curve or whatever they call it to tell you how the temps have to change, you may start at 200 for 10 min then go up to 500 over the course of 5 min or whatever the data sheet says.Quote from: zerohimself on March 01, 2012, 09:53:44 amJust you tube and look at the comments, most people call them out if they are incorrect.Quote from: zerohimself on March 01, 2012, 09:53:44 amRadio shack tends to have good stuff and is convent for most people. Higher quality can be bought online, but for most people you don't need expensive solder.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 04, 2012, 10:57:37 am
content: Quote from: ciccio on March 03, 2012, 05:18:47 pmI always do it,unless I am using Liquid Resin Flux,(which I prefer).It takes less than a second,& new flux is instantly available.not sealed behind a blob of solder!I've seen some pretty horrific professionally soldered joints,over the years.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 04, 2012, 04:46:02 pm
content: It must be nice to be so confident that you are right!The stuff I used for years came in a big bottle labelled "Liquid Resin Flux"!I was introduced to it in the same High Reliability Hand Soldering course which gave me the the tip about snipping the tip off solder.Resin has a long & honourable history of use for flux.Flux melts long before solder,& with a cut end,deposits flux first on the surface to be soldered,allowing it to do what it is designed for.I used "professional" in the sense of "done for a living" rather than as a standard of workmanship.I admit that people such as myself who spent the last 40 years repairing things,normally are not under quite the same time pressure over their soldering as somebody soldering hundreds of joints on PCBs in a production facility.After all,if it takes 30minutes to find a fault,20 seconds extra in soldering doesn't make a lot of difference.Ihaveworked in a production environment,& hated it!.I was probably slower than the others,but I had less boards "bounce".

author: vk6zgo
author_rank: Super Contributor
timestamp: March 05, 2012, 05:54:25 am
content: The Resin/Rosin dichotomy is addressed in the following:http://en.wikipedia.org/wiki/Flux_(metallurgy)&http://www.tequipment.net/pdf/Hakko/TN00000030.pdfBasically,although they are slightly different,many suppliers use the names interchangeably in labelling.Most of us OFs were brought up on the term "Resin",so this is the word we automatically think of.Ididget fired,supposedly because I was slow,but really because I a wasn't "a good little mushroom", & told the bosses when they were making expensive mistakes!I said I'd stay on till they found a replacement.I was there another 18 months before I resigned,in which time,I saw them apply most of my suggestions---of course,somebody else took the credit!

author: Randall W. Lott
author_rank: Regular Contributor
timestamp: March 05, 2012, 07:45:48 am
content: Leave a big glob of solder on the tip after you're done using the iron. This is a protective coating against oxidation. Soldering is not difficult once you understand how it works. Dave's set of videos answer most, if not all, of your questions.I generally stay at 350OC. Occasionally, I need to bring it up to 400 to solder the casing on potentiometers.It's effortless after the proper technique sets in. I'm by no means a soldering expert, but all of my joints turn out excellent with cheap tools. An Aouye soldering station with a crappy conical tip, and cheap 60/40 no-name solder produces great results for me.Make sure that the pin is actually touching the pad. Aerospace requirements say that it should have a strong mechanical connection first, but it should be fine as long as it's adequate. Apply the iron tip to the junction where the pad and pin meet for a few seconds, then apply your solder where the pad and pin meet. Don't touch the tip with the solder wire. Wait just a moment and release the solder, then the tip. Let it sit without moving, as movement during cooling can create bad joints. Congratulations; this should be a perfect joint.

author: IanB
author_rank: Super Contributor
timestamp: March 05, 2012, 07:57:47 am
content: Quote from: Randall W. Lott on March 05, 2012, 07:45:48 amMany tutorials say this, but trying to follow this instruction is going to make the job much harder. Physics says you need some liquid to fill the gap between the iron and the parts to be soldered to conduct the heat across (this is the reason for heat sink paste when bolting components to heat sinks). A bare metal to metal connection is a very poor conductor of heat.Adding extra flux to the joint before applying the iron can help, but solder is a much better conductor of heat than flux. I recommend applying a tiny bit of solder in the gap between the iron and the joint. This has two benefits; firstly it releases molten flux from the wire core and lets it flow over the joint, and secondly it wets the gap between the iron and the joint so heat can flow. Once the joint has reached soldering temperature you can then feed more solder into the joint to properly fill it.You can tell when the joint has worked properly as the molten solder wicks into the gaps and forms concave surfaces. If the solder is beading up then it is not working. This can often be remedied by keeping the iron applied a bit longer until the pad and lead reach proper soldering temperature.

author: Randall W. Lott
author_rank: Regular Contributor
timestamp: March 05, 2012, 09:53:46 am
content: Quote from: IanB on March 05, 2012, 07:57:47 amAfter thinking about it, I actually do touch the tip, pad, and pin with the solder. Thanks for sharing.