ROHS and Lead free electronics

[t20user]

I am an EE and painfully aware of the dilemma that is ROHS compliance. I wonder how many consumers out there are aware of it and what the repercussions will be in the near future with respect to reliability or lack thereof with electronics without lead based solder.

This article is somewhat technical, but it touches on the tin whisker issues and other major problems with ROHS compliant electronics...

http://www.edn.com/article/ca6477864.ht ... =673946062

[dsigma6]

The article certainly made the case against switching from lead based solder. I wasn't aware of ROHS, but I was aware of the plan to rid bullets of lead...

[jdhurst]

I need to get more up to speed on this. I don't see the problem with a soldered joint in use. I can see an issue whilst soldering (but this can be controlled) and there may be an issue with disposal, but recycling is common where I am.

I have been soldering for decades in my basement with no apparent ill effects. I say apparent, because something may later show up.
... JDH

[rkawakami]

http://forum.thinkpads.com/viewtopic.ph ... 574#345574
http://forum.thinkpads.com/viewtopic.ph ... 420#224420

[leoblob]

I am an EE and painfully aware of the dilemma that is ROHS compliance. I wonder how many consumers out there are aware of it and what the repercussions will be in the near future with respect to reliability or lack thereof with electronics without lead based solder.

This article is somewhat technical, but it touches on the tin whisker issues and other major problems with ROHS compliant electronics...

http://www.edn.com/article/ca6477864.ht ... =673946062

Solder companies have been working toward lead-free for years (this didn't exactly sneak up on them) and I think they're solved a lot of the "lead free" issues:

http://www.kester.com/en-US/leadfree/index.aspx

Labs have been offering tin whisker testing capabilities as a standard testing protocol for quite a while:

http://www.tracelabs.com/capability.asp ... lity_id=18

The problem with lead does have to do somewhat with the workers in the assembly plants, but the larger issue is disposal of old electronics that have lead in them. I just recently bought a new video card (but still with lead-based solder), and it was clearly marked "do not dispose of in landfill," like that was my first thought with a brand new graphics card

I would take the opinions of an alarmist "consultant" with a grain of salt.

[joester]

We do a fair share of "Green" solder at work...

Even with the breakthroughs in flux technologies, the solder itself remains more fragile than a 63/37 joint of comparable design and size.

Any assembly exposed to stress (physical or environmental) is more likely to fail unless special measures are implemented to deal with the fragile solder joints. Redesign, underfill, board supports, ect. are typical.

I too live in a community where recycling is wide spread and rather complete. In the 12 years I've lived here, our garbage went from about 2 cans per week to only about 2 per month after recycled materials were seperated out. Our landfill has a Hazardous Waste center, and they accept all electronics except air conditioners and microwave ovens. The collected equipment is sent to be destroyed and the materials reclaimed. It's better than having lead and other compounds leak into the water table and ruin our water supply.

Give the lead free solder technology time to work out all the bugs. It will be second nature within a dozen years or so for most items.

I do wonder about military applications though. The military is typically extremely slow at best in changing technologies for established products and equipment. I doubt you will ever see an F-16 with complete ROHS compliance....

Joe

[ulrich.von.lich]

Very interesting topic.

I recently ordered a T43 motherboard from IBM France. I ordered a leaded replacement (42T0067) but received a lead-free one (42T0069), which is 50EUR more expansive. I called IBM but the guy on the phone didn't seem to know anything. He was repeating the latter was recyclable and the former was out of stock..

I read some posts on the forum but I don't understand why people were associating legacy ThinkPads such as the A21 with the new RoHS thing.

My suspicion is that very likely a tin whisker is causing my A21 trouble. The tin migration problem is evidently a common problem with this RohS compliant stuff (I'm being nice by calling it "stuff"). Laptop mobos aren't the only surface mount technology that's plagued with metal migration.

Correct me if I'm wrong but I believe the RoHS conversion started with the T43. I compared the Hardware Maintenance Manual of T43 to the one of T42/41/40. In the Parts list section (Page 184), it says FRUs marked with R are RoHS compliant., and the sentence doesn't appear anywhere in the HMM of T42 or older TPs, which I assume means no lead-free parts available to order. And in the HMM of T60 and later, almost everything is marked as lead-free.

I've never soldered anything in my life. But given by the fact that T6 series have less mobo problems than T4 series do, is it safe to say that the RoHS thing doesn't necessarily mean the quality decrease?

[rkawakami]

I'd say you have to compare the MTTF (mean time to failure) to determine whether or not the T6x systems are any more reliable than the T4x. My understanding is that when the first lead-free solders were developed back in the middle to late '90s, not much was known about the long term reliability of such materials. As time went by and system failures were noticed and some of them attributed to the brittleness and metal migration of these compounds, alternate "lead-free" solder formulas were devised. Some worked better than others. I think what we are seeing now as system failures in these older equipment will probably lessen with the newer materials as they become more prevalent.

RoHS basically established a point in time at which manufacturers were supposed to be in compliance. That date I believe was July 2006. I'm not sure when IBM, Lenovo or any of their contract manufacturers first started using lead-free solder but I would bet that they were playing around with this stuff around when T2 and A2 system where being built (2001).

ref: http://www.eet.com and plug in "lead-free rohs" in the search field.

[joester]

. That date I believe was July 2006. I'm not sure when IBM, Lenovo or any of their contract manufacturers first started using lead-free solder but I would bet that they were playing around with this stuff around when T2 and A2 system where being built (2001).

Exactly why I would like to try reflowing solder joints on the BGA's of a BOD victim. I have two rework machines available to me....

Joe

[t20user]

I would take the opinions of an alarmist "consultant" with a grain of salt.

I would except that I have a good deal of experience with lead free manufacturing and a lot of what he has to say is very similar to what I see with my own products.

I originally posted this thread after inspecting one of my designs under a stereo-scope and I don't like what I see. The solder joints look poor for various reasons, but I suspect a lot has to do with the solder being lead free. Reworking my boards with leaded solder almost always remedies problems with poor joints. Reworking with lead free solder is night and day, and gives an indication (to me) of the reliability of it.

The other point of note to me is the fact that military manufacturers are exempt. I don't think this is just because they suspect unreliability. I am sure they have done studies, and there are actually some pretty good accelerated life tests that would give good indication of reliability.