Which lead-free solder - Page 1
Forum section: electronics / beginners

author: Medo
author_rank: Regular Contributor
timestamp: April 29, 2011, 08:36:52 am
content: I am switching from lead soldering to lead-free and first step is selecting a solder.I narrowed my choice between 99C and 96SC lead-free solder:96SC:http://hr.rsdelivers.com/product/multicore/442578/96sc-colophony-free-solder-05mm-250g/4364926.aspx99C:http://hr.rsdelivers.com/product/multicore/442555/lead-free-solder-multicore99c-05mm-250g/4364825.aspxWhich one, in your experience, would be better and easier to solder with?

author: flolic
author_rank: Frequent Contributor
timestamp: April 29, 2011, 08:50:47 am
content: Quote from: Medo on April 29, 2011, 08:36:52 amWhy, why, why!? But really?stvarno me zanima

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: April 29, 2011, 08:51:00 am
content: If you really must used leadfree, use the stuff with 2% silver. But if possible stick to leaded.

author: Medo
author_rank: Regular Contributor
timestamp: April 29, 2011, 10:53:07 am
content: Quote from: flolic on April 29, 2011, 08:50:47 amWhy not?There are two reasons really:1. Health. Lead is not that good on hands and sometime I even hold wire with my mouth as I solder. It was either changing wire or my weird soldering style.2. Lot of other components (if not all) are lead-free. Why not switch all the way?nadam se da je ovo dobar odgovor

author: flolic
author_rank: Frequent Contributor
timestamp: April 29, 2011, 12:04:32 pm
content: Quote from: Medo on April 29, 2011, 10:53:07 am1. I agree that lead is not the best thing to put into you mouth, but you overreacting. Try to avoid chewing solder wire and you will be fineTouching solder wire with your hands will have no ill effect on your health if you wash your hands after soldering.2. Lead-free components solder just fine with lead based solderYou can try lead free if you want, but I'm quite sure that you'll be back to "poisonous" stuff soon

author: tecman
author_rank: Frequent Contributor
timestamp: April 29, 2011, 01:39:25 pm
content: One reason is that lead solder is still preferred/required in high reliability applications. Although the world is moving to lead free, none of the available compounds are without problems. The most significant is aging. Non-lead solders can deteriorate, cause dendritic shorts, crystallize and have other breakdown issues that have an impact on joint reliability.As for the health issues, don't chew on the solder, vent the fumes, and keep away from children. In its solid form, lead in the solder is rather inert.paul

author: sacherjj
author_rank: Frequent Contributor
timestamp: April 29, 2011, 02:38:16 pm
content: Quote from: tecman on April 29, 2011, 01:39:25 pmEven in the temperatures used for soldering, Lead is rather inert. The "fumes" are all vaporized rosin flux."Simple lead-tin soldering operations at controlled working temperatures typically do not generate significant lead fume concentrations." Burgess WA. Recognition of Health Hazards in Industry, 2nd Ed. New York: John Wiley & Sons, 1995.

author: Medo
author_rank: Regular Contributor
timestamp: April 29, 2011, 05:09:35 pm
content: Quote from: flolic on April 29, 2011, 12:04:32 pmI know. I've been soldering with lead for quite a few years now. However, I tried lead-free solder and it is not that problematic to use so my thoughts immediately went to switching completely.Quote from: flolic on April 29, 2011, 12:04:32 pmTrue.

author: orbiter
author_rank: Frequent Contributor
timestamp: April 30, 2011, 11:15:34 am
content: I started my electronics hobby off again on the right foot by using lead free solder (2% silver,) however after using it for almost six months I decided (no reason) to just switch to leaded. Only then did I realize what everyone meant when they where saying that lead free was a PITA. Lead free is actually ok to work with and I do still have loads of it and use it sometimes, but compared to the way leaded flows and seems to adhere much easier, I'm staying with it.To be quite honest whilst I don't sit there and sniff the fumes like a drug addict, I am partial to the smell of the Rosin fumes

author: tekfan
author_rank: Frequent Contributor
timestamp: April 30, 2011, 03:29:26 pm
content: Anybody remember this?They're called tin whiskers. There's a reason why they put lead in solder.I guess you can expect every single piece of test equipment with ROHS standard to fail in the next 10 years.This is the primary reason I don't use lead free solder. I want the stuff I build and repair to last.I too sometimes hold the solder in my mouth. I don't worry about it because you absorb much more lead and even mercury by simply drinking tap water or eating fish.Fauliure of a transistor in a tin plated package. You can see the whiskers actually grew trough the silicone paste.For more information on how electronic equipment built today will fail in the next couple of years visit:http://nepp.nasa.gov/whisker/anecdote/index.html

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 30, 2011, 03:47:01 pm
content: my kid just chew a good bunch of solder few days ago, luckily he didnt swallow it. i only notice when i tried to find it and deformed badly, still reusable though. yea, that whisker, the nasty extraterrestial microb i think.

author: Zero999
author_rank: Super Contributor
timestamp: April 30, 2011, 05:54:27 pm
content: Even swallowing a piece of lead solder is unlikely to do much harm, just chewing it is probably more dangerous though.Solid metallic lead is pretty inert and will just pass though the body and be expelled in feces. Lead salts are much more toxic because they will be absorbed into the body tissue and enter the blood. When solder is chewed it will be broken down to small pieces, the thin oxide will be removed and tiny fragments will break off and be swallowed. Swallowing small pieces of lead is definitely more harmful than one large piece because tiny pieces have a larger surface area so more will be absorbed.If you son has been chewing solder take him to a doctor for a blood test. Lead is more harmful to children than adults and has been linked to brain damage and mental retardation, so if he has lead poisoning, the quicker he's treated, the better.

author: tecman
author_rank: Frequent Contributor
timestamp: April 30, 2011, 06:00:06 pm
content: Quote from: tekfan on April 30, 2011, 03:29:26 pmThe whiskers are technically known as dendrites, and they grow with time !Be warned.paul

author: jahonen
author_rank: Super Contributor
timestamp: April 30, 2011, 06:19:40 pm
content: Quote from: tecman on April 30, 2011, 06:00:06 pmWhiskers are quite different from dendrites, dendrites need a surface to grow along, but whiskers can and do grow across air, as they are extruded from the surface upwards.Regards,Janne

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: April 30, 2011, 07:26:13 pm
content: Just to let you guys know - it is illegal to distribute non RoHS compliant electrical stuff on the EU market.It's OK to use Pb containing stuff for "internal use" but as soon as you put it on eBay or sell your design to a friend you are potentially in trouble.As far as I know the US market does not have such restrictions. Thank you Eurocrats for making our life so much better!

author: Unknown
author_rank: Unknown
timestamp: May 01, 2011, 02:25:34 am
content: Quote from: Leo Bodnar on April 30, 2011, 07:26:13 pmAssuming it's in one of the categories as specified by the WEEE directive. And not covered by one of the exceptions (eg. monitoring & control, industrial, aerospace, military). And it's not for repairing equipment build before the directive became effective.I'm not sure if hand soldering with lead-free solder is actually safer, I'd consider the aggressive flux a larger risk than the lead. Flux evaporates during soldering, unlike lead.

author: Medo
author_rank: Regular Contributor
timestamp: May 02, 2011, 12:38:14 pm
content: Quote from: tekfan on April 30, 2011, 03:29:26 pmYou are damned anyhow since almost all connectors and components have tin finish.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 02, 2011, 12:46:08 pm
content: Quote from: Leo Bodnar on April 30, 2011, 07:26:13 pmTechnically yes, but in practice nobody is ever going to find out or care, just like a whole load of other product legislation that is widely ignored.

author: tekfan
author_rank: Frequent Contributor
timestamp: May 02, 2011, 01:11:23 pm
content: Quote from: Medo on May 02, 2011, 12:38:14 pmAs much as only 3% of lead content in the solder completely eliminates tin whiskers. Imagine how little lead there is in a circuit board and how many car batteries are improperly disposed (lead + acid + other very nasty stuff)

author: sacherjj
author_rank: Frequent Contributor
timestamp: May 02, 2011, 02:37:02 pm
content: Quote from: tekfan on May 02, 2011, 01:11:23 pmCome on, you aren't allowed to bring logic when talking about legislation. That requires thinking and when dealing with government types makes it an unfair fight. Because they come unarmed.

author: TheWelly888
author_rank: Frequent Contributor
timestamp: May 02, 2011, 07:12:30 pm
content: Medical equipment is also exempt from the lead free directive. Sadly some have lead free boards now... I know because I had to replace a water damaged PCB with a new one supplied by the manufacturer that has the lead free joints!I had to throw away a digital radio receiver after it was used for only 3 years because the facking thing just failed and the boards were all over the place which made fault finding too bladdy difficult! The joints appeared to be lead free!

author: nukie
author_rank: Frequent Contributor
timestamp: May 03, 2011, 01:54:45 am
content: Let me help you out since all these 'experienced' fellas has their head stuck in the mud for too long.Lead free solder has come a long way and taken the industry by storm. You heard of RoHS? that's lead free for you. Most parts today come in RoHS spec. If you have tin whisker on your board, you have a problem with your manufacturing process. Simple as that.Your answer to lead free is SN100C byNihon Superior. Tin whisker you say?! Things of the pass. You might not know this brand very well but it's widely used in Asian assembly plants. For you guys in the States... Kester has a SN100C clone, it's the K100.AIMmakes them too. Yes they all do different sizes solder wire with flux.Having said that, lead free solder has high melting temperature making them a pain to work with.

author: Rufus
author_rank: Super Contributor
timestamp: May 03, 2011, 02:55:39 am
content: Quote from: nukie on May 03, 2011, 01:54:45 amDo you even know what a tin whisker is?

author: bilko
author_rank: Frequent Contributor
timestamp: May 03, 2011, 10:17:04 am
content: I wouldn't use lead free on anything except cheap throw away electronics with short life span such as most consumer goods. Its Ok to use lead free on cell phones e.t.c. because very few people have phones more than 5 years old. All our repairs are done with lead solder.

author: Psi
author_rank: Super Contributor
timestamp: May 03, 2011, 12:07:05 pm
content: The best lead-free solder to get is the cheapest, dodgiest lead-free solder you can find out of china.Since it's most likely lead solder with a lead-free label

author: tekfan
author_rank: Frequent Contributor
timestamp: May 03, 2011, 12:39:33 pm
content: Quote from: Psi on May 03, 2011, 12:07:05 pmGood one! Also true.

author: nukie
author_rank: Frequent Contributor
timestamp: May 03, 2011, 12:56:53 pm
content: You don't have to worry about tin whisker if you are doing hand soldering. The joints are too thick for them to grow. Tin whisker usually grow on tin coatings which means bare RoHS components are the carriers. If you operate an assembly plant, I suggest you look at SN100C if you haven't already, apparentlyNASA also quite like it...Balver Zinnin Europe produces and sell them under license.Sorry I don't recommend cheap China solder wire . Get something that you can trust, at least you know what's inside your solder.. rosin or RMA. You don't want plumbing solder which is very corrosive. Most cheap Chinese solder I tried behave like eutectic solder and it felt as if the raw material used are not pure enough, this makes reworking the solder joint difficult. The quality isn't great compared to locally obtained cheap 60/40. It's not worth to contaminate your board with whatever formula they had for making that cheap solder, unless you can trust your supplier with the data composition. On the contrary, cheap China solder paste I tried are actually quite good quality.Wherever you are located you should be able to obtain proper solder easily. They are not terribly expensive and a small spool last a long time, provided you are using the right size.

author: Psi
author_rank: Super Contributor
timestamp: May 03, 2011, 03:00:58 pm
content: yeah, i wasn't being serious