Lead vs lead free solder headaches

[tronik25]

Seems like I read a article thats pro lead then the next,pro lead free.Keeps going back & forth.I read in the US,NASA,navy,army,& military still use lead solder on their electronics.

I am in the middle on this,lean a lil more towards lead though.I believe the only reason lead free solder cameout is because of enviomentalists,nothing more.
Many of you probably have experience with both types of solder.
What do you prefer & why?What mix do you prefer?Do each have their limits for certain applications?

I'm sure this topic has came up many times on here

[mariushm]

Re: Lead vs lead free solder headaches

RoHS banned lead based solders in common consumer stuff because these devices are thrown in the general garbage and eventually the lead "leeks" into the ground water.

Lead based solders are still allowed in critical devices (medical equipment), airplanes, industrial stuff and there are quite a lot of other exemptions.

Lead in solder also helps prevent solder whiskers, it reduces the growth but doesn't block it completely (but there are some lead free compositions where solder whiskers aren't possible or the growth is extremely slow).

I personally switch between 63/37 solder and 60/40 solder, but leaning a lot on 63/37. I use 60/40 when I have to desolder stuff or when I have to add lots of solder to something (thickening power traces for example) and I use 63/37 when I actually have to solder something small, temperature sensitive devices etc

60/40 has a plastic region, it stays in a semi-liquid state for some time before getting hard.. which is bad if you move the leads or component while solder cools down. it causes bad joints. But by adding a bit of solder to existing leads and heating each one, you can pull a component out of a board more easily.

63/37 is euctetic, it has a very narrow plastic region of maybe 1-2c degrees. It solidifies almost instantly when temperature drops below around 183c so soldering is very nice with such solder. Heat lead and pad, add solder, remove solder wire, remove iron, done. Quick and reliable.

[c_hegge]

Re: Lead vs lead free solder headaches

Leaded for me. It doesn't crack as easily, nor does it grow whiskers as easily.

[cheapie]

Re: Lead vs lead free solder headaches

Lead based solders are still allowed in critical devices (medical equipment), airplanes, industrial stuff and there are quite a lot of other exemptions.

Now... what does that tell you about how well lead-free works?

(I actually first learned to solder with lead-free, but leaded is a lot easier)

[momaka]

Re: Lead vs lead free solder headaches

I prefer leaded solder, but since I already have a huge spool of 95/5 tin/antimony lead-free solder (it's for plumbing really), I just use that instead - at least for through-hole stuff. With a good soldering station, I don't mind it that much at all. However, when I have to use my other weaker irons, the lead-free really does take its toll and it's much harder to solder/desolder.

Now, when doing any sort of reballing, I always use leaded solder. It allows the balls to melt at a much lower temperature (200C vs. 230C for lead-free) and so puts MUCH LESS strain on the chip. Lead-free isn't so bad for through-hole stuff such as PSUs and even for SMD. But in the BGA world, it is absolutely no good!

[tronik25]

Kester solder

Anyone know where I can buy some kester solder without having to buy a bundle of rolls?
I want to get Sn62Pb36Ag2(62% tin/36% lead/2% silver) #50/245 .025 part #2471508809
Everywhere I look I have to buy a min of 20 to 25 rolls
Sorry I went a bit off topic on my own thread lol.Thought it would be silly to make a new thread just to ask this.

[lookimback]

Re: Lead vs lead free solder headaches

Did you try Ebay yet Tronik? There's guys there who sell Kester solder in 5 and 10 ft lengths.

As for the poll, I've only ever used leaded solder but I just bought a 1lb roll of 95/5 Kester 44 .031 dia today. $46 on ebay. So after I try it, I'll let you know.

[Fwrothy]

Re: Lead vs lead free solder headaches

The thought of lead less solder has me terrified so far... I have been soldering electrical parts since elementary school (back then if u ran out, just dig into dad's toolbox and grab the acid core); since high school it's always been 60/40 radio solder....
I do use leadless on copper pipe for my hot water heating systems ,but that's with a torch not a pencil iron. I have some on order now for my current project an LCD tv we will see how it goes

Btw I thought I read somewhere that it's bad to mix leaded and leadless- causes cracking??

[Sparks88]

Re: Lead vs lead free solder headaches

Leaded but maybe thats what i was brought up on, and it looks a lot better, lead free always seems to look like a dry joint even when its good.

[Elysarian]

Re: Lead vs lead free solder headaches

I hate lead free...

I use 60/40 rosin core for pretty much everything and have done since I was 11

lead-based solder is pretty good for lowering the melting point of lead-free stuff too in my experience (makes de-soldering through-hole components on double and multilayer boards easier)

[eccerr0r]

Re: Lead vs lead free solder headaches

Currently I have three rolls of solder:
63/37 Sn/Pb Kester 44 - I can see the "instafreeze" and very shiny metal joint. Rosin in this works very well for cleaning the joint.
60/40 Sn/Pb Noname - when this "freezes" slowly, it doesn't give a shiny joint. I think that this stuff is good for "diluting" lead free solder a bit. Rosin isn't that great.
99.7/0.3 Sn/Cu Noname - This is my lead free roll in case I have to deal with stuff that I don't want lead to be exposed. I haven't used it much. It has a white rosin core that I'm not sure about...

Unfortunately I don't have a temp controlled iron right now (it broke) and the irons I have all are "too hot" so it tends to melt all the solders quite quickly. Probably also melts bonding pads on IC packages too...

[stj]

Re: Lead vs lead free solder headaches

if you have a soldering station with temp control,
modern lead free solders are great.

the old problems where nothing to do with not having any lead in them.
it was that the flux formula's didnt work on tin/copper or tin/copper/silver very well.

after over 10years of research - that's solved.
i use "multicomp kristall 505" which is 99.3% tin and .7% copper and it's better that leaded but needs a higher temp.
and for "special" small stuff, i use "stannol TSC" which is 95% tin, 1% copper & 4% silver.
this has a lower melting point, but is F'ing expensive because of the 4% silver content.
if it was cheaper i'd use it for everything.

[particleman]

Re: Lead vs lead free solder headaches

Lead for me 63/37 I have been buying 1lb rolls of Qualitek from Philmore.

[Ed Herdman]

Re: Lead vs lead free solder headaches

I have a question on the tin/copper or tin/copper/silver solders: Does the copper or silver lead to any reliability concerns long-term? I am hoping the through-hole repairs and replacements I'd like to do will be essentially permanent (good for decades of service).

The station I'm likely to get is something like a Hakko FX-888D - I'd like to get a JBC but don't quite have the money.

[kaboom]

Re: Lead vs lead free solder headaches

RoHS banned lead based solders in common consumer stuff because these devices are thrown in the general garbage and eventually the lead "leeks" into the ground water.

That's right out of the enviro-nazis' playbook. Landfills, for the last 25-30 years (at least) are lined and have leachate (water) treatment facilities, like a giant swimming pool. There's a complete WWTP which processes leachate before sent to rivers or sewers. In the case of discharge-to-sewer, the end product is actually cleaner than most everything else entering that sewer.


As for the solder itself:

Chlorine and sodium don't "leek" out of common table salt if you dump it on the ground, and chromium sure as hell doesn't "leek" out of stainless steel if you bury it in the ground.

If anything, under acidic conditions, it's the tin that leaches from solder as the lead is protecting it.

Elements vs. compounds.

ROHS belongs in a burning "rowhouse." Another load of "feel-good" bullshit, er bull$$$hit, from "people" deciding, for the rest of us, something that's none of their damn business.

[Agent24]

Re: Lead vs lead free solder headaches

I've not had the 'pleasure' of actually trying to work with lead-free solder and I don't want to.

[stj]

Re: Lead vs lead free solder headaches

I have a question on the tin/copper or tin/copper/silver solders: Does the copper or silver lead to any reliability concerns long-term? I am hoping the through-hole repairs and replacements I'd like to do will be essentially permanent (good for decades of service).

The station I'm likely to get is something like a Hakko FX-888D - I'd like to get a JBC but don't quite have the money.

lead-free solder joints are stronger and have a lower electrical resistance.
but if you use it on stuff exposed to the weather it will go rusty!

[momaka]

Re: Lead vs lead free solder headaches

lead-free solder joints are stronger...

... but easily become brittle with thermal cycles.

I'm okay with lead-free for larger through-hole stuff (like PSUs) and SMD soldering. However, when it comes to really fine SMD work (i.e. fine pitch SOIC) and BGA, lead-free is shit. It grows tin wiskers too easily to be used on very fine stuff and really puts a lot of stress on BGA chips when they are soldered at the factory, because they must get heated to at least 225C (vs. just 200-210C max for leaded solder).