Favorite solder mixes

[ratdude747]

well, as many know, solder comes in many mixes... the most common being either 60/40 and 63/37.

Vote on your favorite mix.

I personally used to like 60/40, but I now find 63/37 to perform much better due to the lower melting temp and lack of a semisolid state.

edit- on another note, if i have to use lead-free for something, i find that 99/0.7 (sn/cu) seems to work well... not as good as leaded, but if leaded isn't allowed, then you do what you have to do.

[c_hegge]

Re: Favorite solder mixes

I can't comment, since I've only ever had 60/40, but it works well for everything I solder

[Agent24]

Re: Favorite solder mixes

Both seem the same to me, or I haven't used 63/37 enough to notice the difference.

[mockingbird]

Re: Favorite solder mixes

I think you have it mixed... The 63/37 HAS the semi-sold state - that means to say - that it will stay fluid for a few seconds even after the ehat source is taken away. I started using 63/37 exclusively now. Either way is ok, I guess.

[Agent24]

Re: Favorite solder mixes

No, 60/40 is definitely the one with the semi-solid state.

[momaka]

Re: Favorite solder mixes

I voted for 60/40, but in reality I'm not really quire sure what I'm using because the leaded solder I have was given to me by my uncle (and if I'm not mistaken, that stuff is leftover from when he was into electronics way back in the day). I works pretty good, though, and the joints come out nice and shiny.

I also have a spool of lead free solder (95 SN, 5 Sb), 3mm dia, and no flux inside. I use that with no-clean flux when soldering SMT stuff.... Works very well actually. Sometimes i used it for recaps as well, especially on multilayer boards, since the flux goes down in the vias, and then the solder follows it and sticks to it.
Most of the time, the joints look fairly shiny too. It's only if I don't heat the component enough or if I move it while the solder is cooling that the joint will look dull.

[shovenose]

Re: Favorite solder mixes

I voted other since I don't know.

[PCBONEZ]

Re: Favorite solder mixes

I think you have it mixed... The 63/37 HAS the semi-sold state - that means to say - that it will stay fluid for a few seconds even after the ehat source is taken away. I started using 63/37 exclusively now. Either way is ok, I guess.

Page 3.

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Lots of other handy info too.
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[Topcat]

Re: Favorite solder mixes

60/40 is my preferred....but 63/37 is also fine. Either will work for motherboard repair. I've found that 63/37 is a tad easier to work with on some of the poorer RoHS mixes, as the 63/37 melts at a little lower temp and seems to make reflowing a little easier....would be helpful to those using lower wattage irons.

[Agent24]

Re: Favorite solder mixes

Page 3.

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Lots of other handy info too.
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I wonder why they don't want people to use water soluble fluxes?

[PCBONEZ]

Re: Favorite solder mixes

I wonder why they don't want people to use water soluble fluxes?

Most of them are corrosive and the byproducts [corrosion] can be conductive so if not properly cleaned up after it can lead to problems.
The biggest problem is probably the tight spots under SMD parts where proper cleaning is difficult.
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In other words, though not advertised or thought of that way, they are basically an acid flux.
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[From here: http://www.residues.com/faqs_fluxes.html ]
Q. What are the dangers associated with water soluble fluxes?
A. Water soluble fluxes (WSFs) are more aggressive in their ability to strip oxides. The degree of aggressiveness depends on the activators used. A WSF, as a corrosive material, does not know when to stop stripping oxide. Consequently, if you don’t clean the flux residues off, then it will continue to eat away the base metal. Electrical leakage currents and metal migration are also common failures with incomplete WSF removal. If you have a crappy cleaning process, expect to see many failures in accelerated testing and in the field.
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[Agent24]

Re: Favorite solder mixes

In other words, though not advertised or thought of that way, they are basically an acid flux.

Oh really? Didn't know that. That might explain some things...

[delaware74b]

Re: Favorite solder mixes

I am using up the last of RadioShack's 'silver bearing' (62%-tin, 36%-lead, 2%-silver) solder I got a few years ago. I also have a 1-lb spool of Kester 60/40 that I purchased with my Weller soldering station last year.