July 30th, 2006
Folks,
As one might expect, repeal RoHS movements
are now occurring. These movements continue to miss or misunderstand a few points which are think are worth clarifying. Their main arguments follow:
1. Lead from electronics is not a significant contributor of lead to the environment.
2. Lead from electronics has never been shown to harmful to humans.
3. Lead from electronics has never been shown to leach into ground water.
These statements are all true, but they miss an important aspect of RoHS. The EU lists the ROHS objective as:
The purpose of this Directive is to approximate the laws of the Member States on the restrictions of the use of hazardous substances in electrical and electronic equipment and to contribute to the protection of human health and the environmentally sound recovery and disposal of waste electrical and electronic equipment.
Safe and easy recycling is an important aspect of RoHS...it supports WEEE. The intent is that recycling will be so much more common that toxic heavy metals must be avoided to assure safe and easy recycling.
Another aspect of the "Repeal RoHS" movement is the stated negative impact of RoHS assembly on the environment. Three of the stated negative impacts are:
1. Increased use of electricity in RoHS compliant assembly
2. Increased mining of tin, a much more rare metal than lead
3. Silver (used in the most common lead-free solder) poses a risk to marine and microbial life
All of the above are likely true, but let's look at the magnitude of the effect:
1. World-wide electricity use is about 15.7 trillion KWhrs. Speedline's Joe Belmonte estimates that the average assembly line will use about 8250 KWhrs of additional electricity each year. Enthone's Yann Morvan and I estimated that there are about 35,000 assembly lines in the world. Hence, the total increase in electrical use is a little less than 300 million KWhrs or 0.0002% of the total world usage. Forgive me if I'm not looking for "brown outs" to occur due to RoHS compliant assembly!
2. According to Prismark about 50,000 tons of electronic solder is consumed per year. Historically, 63% of this amount would be tin or 31,500 tons. So approximately 18,500 more tons of tin will be needed. The United States Geological Survey (USGS)estimates that the total world usage of tin in 2005 was about 337,000 tons. Hence, RoHS will require about 5% more tin. This number compares well to that calculated by the USGS. While 5% is not insignificant, it is not a "first order" effect. I also believe that the recycling demanded by WEEE will result in a lower amount of virgin tin needed.
3. Silver is valuable and its price as skyrocketed in the last few months. Its value will encourage recycling. For these reasons, I believe that no measurable amount of silver will be introduced into marine or microbial environments.
Do the "Repeal RoHS" folks have any concerns that I am sympathetic to? They point out correctly that long term reliability (greater than five years) has not been established. For this very reason, mission critical devices have been temporarily exempted from lead in solder. I strongly agree that work is needed in this arena for to understand the long term reliability effect of RoHS compliant assembly on mission critical devices.
Another issue that is valid is the concern for lead and lead-free assembly existing together. Because of the military's RoHS exemption some companies will have to maintain both types of assembly. This creates a considerable logistics challenge.
What about benefits that the lead-free assembly might provide? The "Repeal RoHS" folks miss a strong plus for lead-free assembly. In the era of cheaper, lighter, faster, and smaller products, lead-free assembly enables closer pad spacings because it doesn't wet as well as tin-lead solder. Hence, many smaller and lighter lead-free products could not be manufactured with leaded solder.
So what do I think the chances of RoHS being repealed? This Wednesday, weather permitting, I will play golf at Dartmouth's golf course. In my youth I had a 4 handicap, however I will be happy to shoot in the low 80s on this outing. I think the chances of RoHS being repealed are less than my Wednesday score beating Tiger Woods first round in the upcoming PGA Championship ...not impossible, but......
Cheers,
Dr. Ron
Oliver Betz:
Dr. Lasky,
your statements sound rather strange to me.
1. It makes no sense to compare the increased energy and tin demand to the total numbers to justify leadfree. If it's worse, it's worse. Else you also had to consider that lead usage in electronic solder is near to insignificant compared to the total lead usage.
2. I really wonder who told you that you can use finer pitch packages with lead free, because it wets worse! Tin whiskers will kill your fine pitch after a short time.
Again, I get the impression that you are an advocate of short-lived "equipment" (or should I write junk?).
Although I also need to sell new stuff, I feel responsible to make it as good as possible.
Oliver
Marcus:
I believe the first three assertions are not entirely correct, especially 2 and 3:
1. Lead from electronics is not a significant contributor of lead to the environment.
2. Lead from electronics has never been shown to harmful to humans.
3. Lead from electronics has never been shown to leach into ground water.
Evidence comes from the export of electronics to countries like China. I recently read about Guiyu, China where the evironmental contamination from electronics recycling is so bad it has made it necessary to import safe drinking water from neighboring areas. See:
http://www.ban.org/E-waste/technotrashfinalcomp.pdf
Why is it necessary to have absolute proof of human harm before we take steps to minimize the damage?
Oliver Betz:
Marcus,
as far as I know, replacing SnPb solder only moves problems to other places, so a reduction "human harm" by LF soldering isn't guaranteed.
Regarding the "Exporting Harm" document:
It's not stated, whether the water samples contained dissolved metallic lead, and it's also not stated whether the lead comes from CRTs or solder.
CRTs have been the main contributor of lead in the past, so the "Composition of a Personal Desktop Computer" table doesn't tell much about the possible lead reduction in E-waste for future products.
The comparison of leaded gasoline and SnPb solder makes this document sensation-seeking to me.
Besides this, you will find more horrible, irresponsible practices in China etc., especially in production. Ceterum censeo, it would be better to fight there.
Oliver