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[This isn't] Why lead free solder sucks... [But it still sucks]

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SilverSolder:
Why lead free solder sucks...

Alex Eisenhut:
User name checks out.

nctnico:
This is not a lead-free solder problem but a production / design problem. You can have the exact same problems with leaded solder. Cold / heat cycles will cause any joint to crack. A rear-view mirror which is baking in the sun or freezing to sub-zero temperatures every day gets a lot of abuse. The cheap PCB material probably doesn't help either. Look at how the glue holding the component on the board has let go as well. The electronics shouldn't be in there. It is simple as that. But GM can do worse like mounting a single-sided board directly onto a diesel engine  :palm:

SilverSolder:

Lead free solder is less ductile than leaded solders - there is less "give".  This is an issue when there are vibrations and mechanical shocks present...   as with a rear view mirror.

In my experience with repairs, bad solder joints is a more frequently occurring phenomenon with lead free than leaded - particularly if a board can flex.

So for lead free, it may be better to design with many small stiff boards than one big wobbly one...

tooki:

--- Quote from: SilverSolder on May 29, 2020, 09:30:59 pm ---Why lead free solder sucks...



--- End quote ---
Oh man, are you just about to get egg on your face, smugly claiming this as a lead-free fail.

That device was made with leaded solder. How do I know?
1. It was built in 2002, years before the RoHS restrictions went into effect.
2. Automotive electronics are exempt from RoHS.

Now, while the wholesale move of non-exempt electronics to lead-free has had the result of many exempt electronics being made lead-free anyway, car manufacturers are notoriously conservative, and wouldn’t have jumped on board so early.

What it proves is that automobiles are a challenging environment for electronics. The failure mode shown is precisely why the passives manufacturers now make chip passives with flexible contact ends, so that board flex, vibration, and thermal cycling don’t cause the joints to fracture.

And yeah, I still prefer leaded solder where I can use it, and I still think the RoHS restriction on lead in solder was the wrong decision. But it’s not proving to be the utter catastrophe that many claim it to be. Nor is lead-free as difficult to work with as so many claim — at least not if you buy quality solder. (The cheap 99.7% stuff really is harder to use, but a quality SAC305 works just fine.)

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