Author Topic: The best solder for electronics (Read 10961 times)

DiegoBrown · « **on:** July 04, 2019, 09:06:34 pm »

Hi! What is the best solder for electronics? Somebody know?

magic · « **Reply #1 on:** July 04, 2019, 09:12:05 pm »

0.7mm diameter Sn60Pb40 with rosin core

Audioguru · « **Reply #2 on:** July 05, 2019, 02:10:38 am »

60/40 solder was used a long time ago and if the connection is moved as it cools then it forms a bad solder joint. Electronics assembly today uses lead-free or 63/37 Sn-Pb. 63/37 solidifies immediately and makes very good joints. The solders have a flux core.

rfengg · « **Reply #3 on:** July 05, 2019, 02:59:24 am »

I bought a roll of the Kester 24-6337-8800 50 Activated Rosin Cored Wire Solder Roll, 245 No-Clean, 63/37 Alloy, 0.031" Diameter (https://www.amazon.com/gp/product/B00068IJOU/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) and was thrilled with the results.
A tab bit expensive but well worth it for me.

0culus · « **Reply #4 on:** July 05, 2019, 03:20:15 am »

Kester 67/37 is my favorite.

bdunham7 · « **Reply #5 on:** July 05, 2019, 04:26:50 am »

https://www.amazon.com/gp/product/B00068IJWC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

You may prefer a larger diameter, but this works for me. I have 10-15 rolls of solder around, but unless I have something big or that needs silver or lead free, this is the one.

tooki · « **Reply #6 on:** July 05, 2019, 05:28:11 am »

Quote from: DiegoBrown on July 04, 2019, 09:06:34 pm

Hi! What is the best solder for electronics? Somebody know?

No, nobody knows anything about it. And I’m sure it’s never been discussed here before...

What I’m trying to say is, do a little search, this is a topic that’s been discussed extensively, even recently, so rather than start a new discussion, try looking for those threads and then just ask whatever isn’t adequately addressed already.

MarkF · « **Reply #7 on:** July 05, 2019, 05:36:23 am »

I have been using the Kester 63/37 because of its abrupt change from liquid to solid (all 63/37 mixes).
I think its 0.031" diameter. Good over all diameter. Might be just a little big for SMD parts.

I just posted this comparison a few weeks ago:

tooki · « **Reply #8 on:** July 05, 2019, 09:21:32 am »

Quote from: MarkF on July 05, 2019, 05:36:23 am

I have been using the Kester 63/37 because of its abrupt change from liquid to solid (all 63/37 mixes).
I think its 0.031" diameter. Good over all diameter. Might be just a little big for SMD parts.

That's my "daily driver" solder, too. Excellent stuff in absolute terms, and at a good price, too. I will probably pick up a reel of the .020" at some point. Or maybe of the Sn62Pb36Ag2, even.

I have a reel of .015" Kester 63/37 with 282 water-white RMA flux that I got from a surplus mail order back around 1990. (Turns out this is quite expensive solder that costs around $200 a reel at normal price!) It works well for SMD, if I don't just decide to drag solder.

HighVoltage · « **Reply #9 on:** July 05, 2019, 09:27:48 am »

Kester 63/37 is my preferred choice as well. Once you get used to it, you never want to use anything else.

NivagSwerdna · « **Reply #10 on:** July 05, 2019, 09:28:54 am »

It depends on the amount of work you do... I do small quantities only and love my https://uk.farnell.com/edsyn/su35100/solder-wire-62-36-2-183-deg-100g/dp/871394

It's 0.35mm Sn62Pb36Ag2 (0.014" in old money)

OP DiegoBrown has 1 Post; Welcome

Monkeh · « **Reply #11 on:** July 05, 2019, 09:39:47 am »

Quote from: Audioguru on July 05, 2019, 02:10:38 am

60/40 solder was used a long time ago and if the connection is moved as it cools then it forms a bad solder joint. Electronics assembly today uses lead-free or 63/37 Sn-Pb. 63/37 solidifies immediately and makes very good joints.

60/40 is readily available and used today and causes no problems.

tooki · « **Reply #12 on:** July 05, 2019, 11:00:38 am »

Quote from: Monkeh on July 05, 2019, 09:39:47 am

Quote from: Audioguru on July 05, 2019, 02:10:38 am
60/40 solder was used a long time ago and if the connection is moved as it cools then it forms a bad solder joint. Electronics assembly today uses lead-free or 63/37 Sn-Pb. 63/37 solidifies immediately and makes very good joints.

60/40 is readily available and used today and causes no problems.

But 63/37 is superior and is only trivially more expensive, so for the hobbyist, I see no reason to use 60/40, which is noticeably more sensitive to movement during solidification, producing what's called a "disturbed joint".

magic · « **Reply #13 on:** July 05, 2019, 11:46:21 am »

You guys are nuts with that eutectic obsession

I for one actually like Pb-free because it is very easy to remove from PCB in its "paste" phase. No wicking, no sucking, it just comes off.
I don't use it mainly because of higher temperature and out of worry about whiskers.

kosine · « **Reply #14 on:** July 05, 2019, 11:51:57 am »

Yes, the 63/37 alloy is known as eutectic ("melts well" in Greek). Basically means it has a single melting/freezing point rather than being semi-molten over a range of temperatures.

There are other alloys with similar properties. https://fctsolder.com/eutectic-solder/

60/40 isn't that much worse, and the cheaper varieties probably aren't exactly 60/40 in any case.

Personally, I've always found the thickness of the solder wire to be more important. The thinner stuff seems easier to work with for most components. As long as it contains flux - though a flux pen makes things much easier in any case.

Psi · « **Reply #15 on:** July 05, 2019, 11:55:50 am »

+1 for Kester 67/37 flux type 285 (mildly activated rosin flux classified as Type ROL0)

But it's not the cheapest.

I like having two thicknesses on hand.
Thick - 0.7 or 0.8mm (wires / big parts)
Thin - 0.3 or 0.4 mm (Small SMT)

tooki · « **Reply #16 on:** July 05, 2019, 11:14:07 pm »

Quote from: magic on July 05, 2019, 11:46:21 am

You guys are nuts with that eutectic obsession

It's not an "obsession" to have a preference for the superior product, especially when the added cost is truly insignificant.

bd139 · « **Reply #17 on:** July 05, 2019, 11:24:06 pm »

Felder 62/36/2. Eutectic silver bearing joy that stuff is.

Monkeh · « **Reply #18 on:** July 06, 2019, 12:36:58 am »

Quote from: tooki on July 05, 2019, 11:14:07 pm

Quote from: magic on July 05, 2019, 11:46:21 am
You guys are nuts with that eutectic obsession
It's not an "obsession" to have a preference for the superior product, especially when the added cost is truly insignificant.

That very much depends on your relative availability..

Pretty much the same solder I use daily: https://uk.farnell.com/multicore-loctite/3096525-m/solder-wire-60-40-180-deg-250g/dp/5090787
A eutectic (not 63/37 because they don't stock it..) equivalent: https://uk.farnell.com/multicore-loctite/dlmp24-250g-reel/solder-wire-lmp-0-56mm-250g/dp/419552

Truly insignificant, merely 50% more for 2% better solder.

0culus · « **Reply #19 on:** July 06, 2019, 12:45:54 am »

I'd say having a clear state transition point is worth more than 2%.

Monkeh · « **Reply #20 on:** July 06, 2019, 12:52:31 am »

Quote from: 0culus on July 06, 2019, 12:45:54 am

I'd say having a clear state transition point is worth more than 2%.

15 years of soldering with all alloys, well.. stop soldering on a motel bed.

M4trix · « **Reply #21 on:** July 06, 2019, 12:53:11 am »

Quote from: magic on July 05, 2019, 11:46:21 am

I for one actually like Pb-free

mrpackethead · « **Reply #22 on:** July 06, 2019, 01:57:25 am »

Quote from: magic on July 05, 2019, 11:46:21 am

I don't use it mainly because of higher temperature and out of worry about whiskers.

IF you are worried about whiskers when using Pb Free Solder, then dont' use a Pure Tin plated PCB. But that has'tn been really done for years. ENIG, or HASL finish, and you wont' get whiskers.

mrpackethead · « **Reply #23 on:** July 06, 2019, 01:58:28 am »

The real answer is 'it depends'. Theres a reason why there are many different types of solder. Theres no one answer to this question.

magic · « **Reply #24 on:** July 06, 2019, 06:52:45 am »

Quote from: mrpackethead on July 06, 2019, 01:57:25 am

IF you are worried about whiskers when using Pb Free Solder, then dont' use a Pure Tin plated PCB. But that has'tn been really done for years. ENIG, or HASL finish, and you wont' get whiskers.

Won't they grow out of the solder blob rather than the PCB footprint?


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Author Topic: The best solder for electronics (Read 10961 times)

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