Lead-free soldering  - Page 1
Forum section: electronics / general

author: joniengr081
author_rank: Regular Contributor
timestamp: March 08, 2023, 08:55:29 am
content: Hi,I am wondering which lead-free solders are commonly used in lead-free soldering. Do they still have lead portion or absolutely no lead at all ?

author: sinewave
author_rank: Unknown
timestamp: March 08, 2023, 11:42:38 am
content: Of course, no lead, as that is the whole point of lead-free solder, to remove the hazardous metals and be compliant with ROHS and other similar certifications. If you are looking to get some lead-free solder, don't get it from Aliexpress or ebay, get it from a known distributor as often ebay/aliexpress solder can occasionally have lead when marketed as lead-free,

author: joniengr081
author_rank: Regular Contributor
timestamp: March 08, 2023, 11:59:53 am
content: Can you please name some lead-free solders that can be bought ?

author: wraper
author_rank: Unknown
timestamp: March 08, 2023, 12:12:23 pm
content: For hand soldering SN100C or it's clones. For solder pastes SAC305.

author: joniengr081
author_rank: Regular Contributor
timestamp: March 08, 2023, 12:32:02 pm
content: Thank you.

author: SMTech
author_rank: Frequent Contributor
timestamp: March 08, 2023, 12:41:58 pm
content: Quote from: wraper on March 08, 2023, 12:12:23 pmAre two common choices and the ones you'll find most readily...Take a look at this page,https://www.warton-metals.co.uk/solidsolderwire.aspxthis manufacturer will make wire in multiple gauges out of any of those alloys. Some will be on the shelf, some are basically custom. On top of that you also get to choose the flux that is used in the core, halide free, colophony free, no-clean.For a small workshop you might perhaps want a solder wire with a small amount of silver in it because it runs nicely such as 96SC, you might also not have HEPA filtered extraction so colophony free might be nice so the fumes are not (yet known to be) a health a hazard. You might want a low melting point and so go Bismuth (but then you need to know the downsides). Similar choices can affect your choice with paste, SAC305 has a little silver, that makes it more costly so huge volume asian manufacturers spend the extra time dialling in SN100 pastes instead.The flux is key, it will define how a wire feels to solder and how your joints look in paste (as well as some invisible stuff on other packages), I'd trust the flux chemistry of an Aliexpress paste even less than the metallurgy.

author: jmelson
author_rank: Super Contributor
timestamp: March 09, 2023, 07:17:18 pm
content: Quote from: joniengr081 on March 08, 2023, 11:59:53 amI have had great results with GC10 (sold in the US by Loctite). It seems that there has been a change in the distribution arrangement of this, recently.But, it is awesome stuff, and gives as close to 100% perfect soldering on difficult boards as I have ever seen. (This all is about solder PASTE, but that is almost all I do for assembly.)Jon

author: jmelson
author_rank: Super Contributor
timestamp: March 09, 2023, 07:21:19 pm
content: Quote from: SMTech on March 08, 2023, 12:41:58 pmI went to great effort, after a stellar recommendation, to import Warton paste to the US. It worked fantastically well, and solved a LOT of rework issues I was having. But, there was no way to buy it off the shelf in the US. Loctite GC10 worked as well, and was far easier to get here.Jon

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: May 07, 2023, 04:48:57 pm
content: I’m using Weller SAC L0, it’s 96.5% tin, 3% silver, 0.5% copper, rosin flux. Melting point 217C. Widely available and from 0.3mm to 1.6mm diameter.It works well for me, although not everyone is in favour of rosin flux.

author: nightfire
author_rank: Frequent Contributor
timestamp: May 07, 2023, 08:21:36 pm
content: Quote from: joniengr081 on March 08, 2023, 11:59:53 amIn Europe Felder is a big name, I am quite happy with the Sn100C (fuji patented, SN100Ni+) stuff they do.In Germany Reichelt and Voelkner are very good suppliers.Depending on the scenario the stuff is used, I remember that you can get it with different versions of flux.Personally, I use the 1mm version of it, and I am quite happy for classic handsoldering and Through-hole components.Further numbers:Manufacturer-Nr.: 5552941010EAN: 4005796520110Lot: Sn99,25Cu0,7Ni0,05 (ISO 9453: 2014)Nach Fuji-Patent DE 19816671C2Flux: REL1 (EN 61190-1-1/ J-STD-004), 1222 (ISO 9454-1:2016), Flussmittelgehalt: 3,5 %SIR (IPC-TM-650, 2.6.3.3) : >100 MΩ

author: joniengr081
author_rank: Regular Contributor
timestamp: May 08, 2023, 07:56:57 am
content: Which temperature you use in the soldering iron for the solder material (SAC L0, 96.5% tin, 3% silver, 0.5% copper, rosin flux) ?

author: SMTech
author_rank: Frequent Contributor
timestamp: May 08, 2023, 04:12:56 pm
content: Depends on your iron and what you are soldering....

author: Solder_Junkie
author_rank: Frequent Contributor
timestamp: May 09, 2023, 10:05:23 am
content: Quote from: joniengr081 on May 08, 2023, 07:56:57 am350C to 370CTo some extent it depends on the iron/bit/area of copper. For example my Weller WE1010 soldering station has a bit which only weighs 5 grams, it is a "70 Watt" iron. My Antex XS25 with a 6mm angled bit has a bit that weighs 14 grams, despite being only "25 Watts" the Antex can solder quite a large area of copper on a board without a problem, whereas the Weller tip cools too quickly to solder large areas without needing several seconds to build up heat. On the other hand, the Weller doesn't overheat, can turn itself down to 180C when idle to save the bit, and is great for general PCB soldering with small parts.Horses for courses, the Antex is not temperature controlled and tends to run too hot at over 390C, a bit rough for delicate work as the solder/flux can splatter and you don't want that.SJ

author: MarkR42
author_rank: Regular Contributor
timestamp: May 23, 2023, 03:59:36 pm
content: Quote from: Solder_Junkie on May 07, 2023, 04:48:57 pmYes absolutely, +1000 for Weller SAC it's just *waaay* better than cheap lead-free solder.While it doesn't have a super shiny finish, it just melts and flows so easily compared to the cheap stuff. Would definitely recommend. It's obviously a bit more expensive but worth it if you're doing anything remotely difficult or higher quantities.