I guess I have another question based off what you're saying.
Aside from silver plated or specialty parts in an old scope, is there any harm done in using real solder in a RoHS device?
Here's an example.
a resistor mounted through-hole has a bad joint. Normal repair just reheat the joint and add more solder. No problem.
Say it's Rohs assembly this time around. Will regular 60/40 even melt and fuse with the lead free stuff, or you do you need to remove the tin stuff and then resolder from scratch, or is it really just best to resolder with lead free solder?
I've not tested it, because I really don't want to botch up my tips, sponges all that stuff.
Interesting. I may need to tear apart some equipment I have and compare. It's alleged the the new version is rohs while the last one are conventional.
Well, it was silver-*bearing*: still mixed with lead, no? (I assume this is pre-RoHS.)
--
The fashion in killing has an insouciant, flirty style this spring,
with the flaunting of well-defined muscle, wrapped in flags.
- Comment from an article on Antiwar.com (http://antiwar.com)
So adding tin/lead solder to a silver component terminal turns the connection into what, a non-conductive roofing shingle or something? I'm pretty sure I would have heard from a customer or two if the thousands of RoHS components I've soldered with 63/37 weren't conducting electricity.
I've reworked a thousand "RoHS" boards with good 'ol 60/40 and have never had a failure of one of MY joints, or any problems related to them. The stupid part of all of this is, just how are you going to know EXACTLY which lead free solder was used to begin with? There a a lot of formulations, from good 'ol SAC (Tin, silver, copper) to a bunch of alloys with all kinds of weird stuff in them. So, if you grab a spool of SAC and the OEM used a bismuth or zinc alloy, what is going to happen? I just clean up as much of the original solder as possible with solder wick and put down 60/40 and forget about it. I might also add, that we have mixed RoHS and non-RoHS parts for years with no failures due to the tin/lead solder. In fact UPS has destroyed more boards by running them over than any other failure mechanism.
Well this sounds like good news. Thanks for pointing out the solder wick. I don't generally use the stuff, but it's does a good job of removing as much old solder as possible.
In general, based on practical experience, I think I would agree with you. I have also reworked joints on boards that were built with lead-free, but not subject to the European regs, with regular 60/40 lead solder, and I have never knowingly had a problem - at least short term. But who's to say what the long-term effects may be? I mentioned in my original reply about the 'metalurgical wisdom' in this regard. I got this direct from conversations with a Dr Paul somebody-or-other who is an expert in the field and head of the subject for a UK consultancy firm, when I was researching for an article that I was writing on the subject, for a UK trade magazine. He had produced a paper which was available on the 'net, and he was quite adamant that the two solder types should not be mixed in the same joint, because of long term degradation of the integrity of the joint. I've no idea whether this belief was theoretical or based on experimentation, as I did not ask the question. That sort of depth was beyond the scope of the article.
On balance, I still feel that the right *overall* practice, is to rework joints with the same basic formulation as they were made with. Obviously, it's not going to be a major problem if a reworked joint in a TV set or whatever, fails down the line because of it having been reworked with the wrong solder type, but I would hate to think that some item that I had repaired finished up in a critical application, and later failed because of me. Remember also, that most of us outside of the USA are in a slightly different position from you folks in that we must not, officially under threat of law, do anything to compromise the RoHS certification of a product. That includes using non RoHS compliant replacement parts, and solder to fix them in with ... :-\
It is not possible to do "long term" experiments , you have to do accelerated aging and hope it is comparable. Now one way to accelereate aging effects of solder integrity is to subject boards to vibration and cycles of heating and cooling, er come to think of it ......
I'm just curious, how would this "threat of law" scenario play out? Assume some authority finds out that you've got a roll of 63/37 stashed under the floorboards, (or a bin of old leaded components) and you pull it out on occasion for an illegal repair. Would the cops come? Throw you in the slammer? Would you be facing jail time, a fine, revocation of your business license?
I'm reminded of my business neighbor a number of years back, who had a
600 watt amplifier on his CB radio. (Legally, CBs are limited to 4 watts, IIRC) I called the FCC, gave him his name and address. They said, "Sorry, we don't enforce that law. It's too costly."
I'm guessing you're in an analogous situation, and that short of hanging a giant neon sign over your shop that says "f*ck RoHS, we still use lead," you'd never be bothered. But, my guesses are often wrong ...
The usual procedure with laws like this is to find one small operator who has made a mistake and smash him to pieces with the maximum of publicity. It is supposed to frighten the others and is a lot cheaper than chasing them as individuals.
It would have been a lot better if the manufacturers in other countries had got together and told the EU that they were going to continue to use lead in their solder. If Europe didn't like it, they could do without the products. (Did I hear somewhere that this was exactly what the Swiss watchmaking industry did - or did I imagine it?)
--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk
Yes, Smitty. Adrian's analysis is about the measure of the situation. There is nothing illegal about owning leaded solder, and stocking non RoHS compliant parts. There is nothing illegal about using them to repair equipment which is either pre-compliance vintage, or exempt from the regulations. Much equipment that I repair in fact falls into those categories. There is also no requirement for anything that is built not to be intentionally for sale to the general public, to be RoHS compliant.
I am reminded of a famous case here in the last few years. The EU mandated that food items offered for sale loose, must be sold in kilos only. A small greengrocer somewhere up north, continued to price and sell his produce in pounds and ounces, as he said that many of his older customers simply did not understand the new-fangled metric measurements, and still preferred to understand the price of a pound of tomatoes, rather than trying to work out the half-kilo price from the whole kilo. As far as I recall, he was also displaying the prices in kilos, but as a secondary figure rather than the primary one. He was descended on by the local weights and measures department, along with the police, and was arrested for his crime. He was subjected to a full blown 'show' trial and was actually ultimately jailed for his efforts because he rejected the findings of the court, and refused to pay the fine.
He fought the courts through the appeal process for some time afterwards, but the stress of it all brought on a massive heart attack, and he died aged just 39 ...
He had huge, and I mean huge, support from the public for making his stand, but it made not a jot of difference. The authorities obviously decided right from the start that they were going to go after this guy, and prosecute him to the full extent of the ridiculous law forced on us unconstitutionally, by the EU.
See
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picked at random from many hundreds of web entries.
So, Smitty, that's what's meant theoretically - and sometimes in reality - by "under threat of law", and I sure as hell am not going to put myself in the EU firing line by anything that I do professionally. I have no desire to become the first 'Solder Martyr' ... :-|
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