Solder choice questions... Is 2% silver ok for general purpose? - Page 1
Forum section: electronics / beginners

author: mejobloggs
author_rank: Newbie
timestamp: February 05, 2021, 01:01:04 am
content: Wanting to learn soldering and just watched EEVblog #180 - Soldering Tutorial Part 1.He says the 63/37 solder is slightly better and I noticed I can get it for cheaper than normal solder currently (nice deal near me)https://www.synergyelectronics.co.nz/store/asahi-silver-solder-0.4mmManufacture link with spec sheet here (FC5000):http://asahisolder.com/product/fc5000/The only catch is it has 2% silver in which I can't find much info if that's ok for general purpose soldering?I saw some mention that solder with silver in might react if you solder something with gold. E.g perhaps gold plated cables/connectors? If that's true then it makes it less "general purpose", although I'm not sure how much stuff is gold plated anyway so maybe it's not an issue?I plan to move to SMD/PCB soldering once I have learnt enough.Thanks

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 05, 2021, 09:55:31 am
content: Sorry, I think your supplier messed up. This is not 2% silver solder. It is SnPb tin-lead 63/37 with 2% by weight offlux.You won't find the word "silver" anywhere in the datasheet, and "ag" shows up in "storage"...

author: mvs
author_rank: Frequent Contributor
timestamp: February 05, 2021, 01:08:51 pm
content: Quote from: Alex Eisenhut on February 05, 2021, 09:55:31 amDatasheet (fc5000) is for flux, not for a solder wire. On the bobbin photo in the first link you can see alloy spec Sn62/Ag2.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 05, 2021, 04:25:51 pm
content: Well, someone is in error. The datasheet in the second link goes herehttp://asahisolder.com/wp-content/uploads/2018/09/DS_Sn63Pb37-FC5000-Core-Wire-E-Ver-2.pdfSn63Pb37 FC5000Halide Free No Clean Core WireAlloy Composition Sn63Pb37Flux Content 2.0 +/- 0.2 wt%Definitely for solder wire...Not a very clear or specific way to describe its part numbers. It looks like everything they make is called FC5000.

author: wraper
author_rank: Unknown
timestamp: February 05, 2021, 04:47:40 pm
content: Quote from: Alex Eisenhut on February 05, 2021, 04:25:51 pmFC5000 is flux, not solder as already said. Your datasheet is for different solder with the same flux.

author: wraper
author_rank: Unknown
timestamp: February 05, 2021, 04:50:04 pm
content: http://www.pripoi-asahi.ru/pdf/FC5000_E.pdfQuotehttp://asahisolder.com/wp-content/uploads/2018/07/DS_Sn62Pb36Ag2-FC5000-Core-Wire-E-Ver-2.pdf

author: dferyance
author_rank: Regular Contributor
timestamp: February 05, 2021, 05:26:56 pm
content: For learning / hobby, I'd be far more concerned over the flux than the exact metal ratios. As long as it is electronics solder with a small diameter it doesn't matter much for these uses. But the quantity and type of flux can make a big difference. Even then, I'd recommend getting some extra flux.

author: wizard69
author_rank: Super Contributor
timestamp: February 05, 2021, 06:27:50 pm
content: Quote from: dferyance on February 05, 2021, 05:26:56 pmSomething I learned the hard way, really late in life. The flux in most flux cored solders is not all that great for many jobs. It certainly pays to use extra flux in many techniques or situations. It might even pay to have more than one type of flux.

author: BrokenYugo
author_rank: Super Contributor
timestamp: February 05, 2021, 08:16:00 pm
content: Flux is important and undervalued, some flux core solders are better than others, but I think flux core solder by itself is really only meant/good for soldering clean new components to clean new boards. Any sort of repair, rework, tarnished old stuff, bare copper wire, etc. and it's hard to get nice joints and good behavior in general without extra flux.I split my soldering experience between before and after the day my bottle of MG 835 RA and a couple nail polish bottles arrived.

author: mejobloggs
author_rank: Newbie
timestamp: February 05, 2021, 09:39:06 pm
content: Thanks for the replies everyone.Yes I have been very confused about FC5000 whether it contains silver or not but you guys have cleared up my confusion about that too. FC5000 is available with different compositionsWill definitely be getting a small tin of flux as well

author: TimFox
author_rank: Super Contributor
timestamp: February 05, 2021, 10:15:56 pm
content: The short name for the ternary-eutectic solder is "SN62", which means 62% Sn, 36% Pb, and 2% Ag. It is my normal solder (for lead-containing solder), and has a melting point slightly lower than the common (no silver) binary-eutectic "SN63", which is 63% Sn and 37% Pb. "SN60" is a more common leaded solder, close to eutectic, which is 60% Sn and 40% Pb. The silver does increase the price over Sn/Pb. Melting points (deg C):SN60: solidus 183, liquidus 190 (non-eutectic)SN63: solidus = liquidus = 183SN62: solidus = liquidus = 179where the alloy is totally solid below "solidus" and totally liquid above "liquidus". Non-eutectic alloys have different solidus and liquidus temperatures, and will be "mushy" between the temperatures; they can be considered as the excess metal (Pb in SN62) dissolved in the eutectic alloy. For comparison, a non-leaded binary eutectic isSn 96.5 and Ag 3.5 eutectic alloy: solidus = liquidus = 221

author: Microdoser
author_rank: Frequent Contributor
timestamp: February 05, 2021, 11:12:36 pm
content: My personal favourite for solder wire is Sn60/Pb38/Cu2, being 60% tin, 38% lead, and 2% copper with a melting point of 183C. I also have Sn62/Pb36/Ag2 which allegedly has a melting point 4 degrees lower at 179C, yet strangely I find it harder to melt, and it does not seem to flow as well. I've tried 63/37 but the joints always seem to turn out a little dull. Might be because the 63/37 I have tried was lacking in flux. Anyway, I just got 500g of 60/38/2 so I will be using that for quite a while to come.It seems the 2% copper is supposed to keep your soldering tips in good condition longer. Personally, I am not in a position to be able to judge the difference because I got a large roll many years ago, and it is the only solder I have used consistently. I have tried others and always go back to it.What I do know is that I am always confused when I see people complain about their soldering tips degrading quickly because I have never experienced that.

author: TimFox
author_rank: Super Contributor
timestamp: February 05, 2021, 11:54:07 pm
content: The 2% Cu alloy was marketed as “SavBit” since it reduced loss of copper in unplated tips. The 2% Ag alloy was required for the metallized ceramic terminal strips in classic Tektronix equipment. Also, the internal metallization in smt ceramic capacitors is PdAg. A nickel barrier prevents the silver leaching out into non-silvered solder, but I once had to use non-Ni caps to avoid ferromagnetic problems and soldered with Sn62 solder cream (pre-ROHS).

author: Microdoser
author_rank: Frequent Contributor
timestamp: February 06, 2021, 11:10:28 am
content: Quote from: TimFox on February 05, 2021, 11:54:07 pmI don't think I have used an unplated copper tip. All I can say is I have never had a tip go bad, usually the station gets old and dies before the tip needs replacing.

author: wraper
author_rank: Unknown
timestamp: February 06, 2021, 01:44:54 pm
content: Quote from: TimFox on February 05, 2021, 11:54:07 pmFor a long time it's not true except some very expensive MLCC. Modern capacitors have nickel internal electrodes.

author: TimFox
author_rank: Super Contributor
timestamp: February 06, 2021, 02:49:17 pm
content: My understanding is that Class 1 MLCCs (C0G) still use noble metal electrodes (e.g., PdAg), while Class 2 MLCCs (X7R) have changed over to base metals (in this millenium) due to cost, at some expense of performance, Since Class 2 performance is mediocre, this is an acceptable compromise.

author: wraper
author_rank: Unknown
timestamp: February 06, 2021, 02:54:05 pm
content: Quote from: TimFox on February 06, 2021, 02:49:17 pmUsual C0G does not use noble metals. Here is drawing from TDK

author: TimFox
author_rank: Super Contributor
timestamp: February 06, 2021, 02:54:53 pm
content: Apparently, the PdAg terminations are not ROHS. I can't find quickly any information on internal metals.The experience I related with non-barrier capacitors was from work in NMR imaging, where we could not tolerate ferromagnetic materials. I remember one factory engineer (discussing a TH part) who assured me that his capacitors were not ferromagnetic, since "the leads were pure nickel."

author: wraper
author_rank: Unknown
timestamp: February 06, 2021, 02:58:26 pm
content: Quote from: TimFox on February 06, 2021, 02:54:53 pmAgPd terminations are used in caps intended for attaching with conductive adhesive, not soldering.

author: TimFox
author_rank: Super Contributor
timestamp: February 06, 2021, 03:01:33 pm
content: We had no trouble with surface-mounting normal PdAg-metallization MLCC (1206 and 0805) and the very expensive ATC porcelain capacitors with SN62 solder cream and standard tooling. ATC and some other vendors would supply us these parts on special order without the nickel barrier. Apparently, these constructions have changed since the time where they were critical to my work (decades ago).

author: TimFox
author_rank: Super Contributor
timestamp: February 06, 2021, 04:23:48 pm
content: Quote from: Microdoser on February 06, 2021, 11:10:28 amYes, I remember when I used unplated copper tips in a small (20 W) iron and a Weller 100/140 W soldering gun with SN60 and SN63 solder. The small iron’s “chisel” tips would erode in the middle of the beveled end: for a short time, they would be ideal for soldering around a small wire or pin to a PCB pad but then became uselessly blunt. The soldering gun tips would always fail near the formed end, on the lower side where the end joined the square cross section, eroding until the loop opened. (I never tried the Cu-bearing solder.) However, my current tool is a modern temperature-controlled iron with a plated tip, and I have had no trouble with SN63 or SN62 (my current solder, apologies to the ROHS authorities).

author: rsjsouza
author_rank: Super Contributor
timestamp: February 06, 2021, 05:15:38 pm
content: I have used 60/40 for most of my electronics life without a problem, although I am finishing my last roll to move to 63/37.Also, as mentioned, the only tips that really suffered were also the ancient 20~30W soldering irons - my current Hakko FX888 has been working with the same tip for quite some time.Ah, my Weller pistol gun also suffered with it, but I don't use it very often anymore.