Yes, this is very true. There is no "better" solder necessarily, as different applications call for different metallurgies.
The thing about lead-free solder that most people don't realize, and what leads to a lot of its bad rap, is the fact that it doesn't produce nice shiny solder joints like a good lead solder will.
With lead solder, the color of the solder joint is a very good indicator of how well the electrical and mechanical properties of the joint are. Lead-free solder can make a perfectly good solder joint that looks dull and "cold", and it takes a long time to mentally adjust yourself to that, leave the joint alone, and go on to the next one. People used to lead solder will tend remove the old joint and re-solder it over and over thinking that they are getting a "cold joint" or a contaminated joint. This leads to frustration and reports that the non-lead solder isn't as good.
One thing's for sure, it definately requires more heat. I try to avoid it when working on heat sensitive components for that reason.
There are MANY different lead-free solders on the market. I have most recently used the green labeled version by Kester, which uses antimony instead of lead. Not exactly a less toxic metal in my personal opinion, though the amount of antimony is low and just added to increase strength.
I agree that through-plated holes in the PCB would have likely prevented this issue. Just remember - failure in less than 5 years = money loss. Failure after that period means money gain. That calculus finds its way into manufacturing decisions, you can bet on it.
Quote:
Originally Posted by mpolli
There is a move to lead-free solder. The so called "RoHS" requirements went effective last July. There are exemptions for many industries including automotive, however not all companies use all the exemptions. The European manufacturers have been early adopters of environmental practices.
You are making 2 different points here:
1) 'When resoldering you should remove all the old solder and use new solder'.
You are absolutely correct. 100%. This is exactly what should be done. I mostly use a "Soldapult" solder sucker, but wick also works fine.
2) 'Lead solder is "better" than lead free solder'. Strictly speaking this is not correct. I have seen no claims from anyone in the industry that lead free solder is inferior to lead solder. However, it needs a higher temperature and there are several different alloys being used, so from the point of view of the DIY'er (including me) I use tin/lead 63/37 solder. This is also sometimes known as Eutectic.
As I believe I previously stated, the trouble is in the single sided PCB with no plated through holes. This type of board is cheap cra* that does not belong in a Mercedes. It doesn't belong even in a Hyundai IMHO. These boards WILL fail in industrial applications or in any application with heat cycling such as in TV sets etc.
So, remove the old solder, clean the area with a clean toothbrush, use new 63/37 lead solder.
Mike
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