April 25th, 2007
Folks,
I recently received this note:
Hello Dr. Ron,
A colleague of mine sent me the following article. I'm about to start the Pb-Free implementation and wondering where do we stand.
Regards,
Max
The article referenced was from a Dr. Howard Johnson and it delineated all of the reasons lead-free solder is a bad idea. The article also discussed John Burke's Operation Push Back. While Johnson's article makes some good points, repealing RoHS now would be about like repealing the US IRS taxation code. It's not going to happen. The lack of any real hope of a repeal of RoHS is strengthened by the likes of IBM, Motorola, HP, Nokia, and a host of world wide industrial electronics leaders obeying the new law and delivering products with acceptable field performance.
There will always be anecdotal data to suggest lead-free reliability has concerns, but with 100s of millions of products out in the field since 2001, with no credible large scale problems, the reliability "crisis" of lead-free loses its punch.
Cheers,
Dr. Ron
John Burke:
Hi Ron,
You must know something we don't to be so confident - please share.
I have not heard from the EU consultatnts on the result of exemption stakeholder consultation round 6 - do you have an inside track?
John
Scott:
How would you answer this:
Not long ago, the EU TAC issued an exemption allowing the use of lead
In the finish of components that had a very small distance between terminations. Lamentably, this was a case of too little, too late. Tin whiskers can get very long. While not common, cases have been found with a length approaching two centimeters. I published a paper five years ago on a spectacular failure of an electronic component used in a military system. It failed after over a decade in the field due to whiskers that grew inside. A similar unfailed component when opened had hundreds of whiskers longer than one centimeter.
Besides, by the time that the permission to use lead was issued, component manufacturers had already switched to lead-free tin. It isn't practical for them to apply tin to some component terminations and tin-lead to others.
The result is that many of the components we buy will be available with only lead-free tin as a finish. My company pays component engineers to review each such case to assess the risk to our hardware, which I remind you, is used for military purposes and is expected to operate for decades without failure. Each such review is expensive. For equipment destined to operate in space, the use of tin without lead is strictly prohibited.
In each case where the determination is that we cannot take the risk, we are faced with the prospect of redesigning the equipment to get by without it (often not possible without serious performance consequences) or getting the terminations dipped in ordinary tin-lead solder (all the way to the body, with attendant risk of damage due to asymmetric heating). The US Navy recently spent a million dollars on a project to assess the risk of heat damage to tin-plated components that had to be solder dipped to render them usable by some of its programs.
One company has developed a business of replacing the lead-free tin plating on a certain type of component with tin-lead plating by a proprietary process. It should be obvious that had it not been for RoHS, these activities would be unneeded. The costs and risks of handling delicate components alone are significant, but for those applications where the components are needed to achieve performance requirements, there is no alternative.
Our risk of field failures due to the RoHS directive is greater than what I have discussed so far. In addition to building EEE we buy many electronic subassemblies. Where those subassemblies are commercial off-the-shelf, we have no control over what components get used or how rigorous a risk analysis has been conducted before a component is selected. The manufacturer can change the components used at any time without even notifying us.
In conclusion, I understand that your questionnaires are intended to be used to supply data for a cost-benefit analysis. Regrettably, the benefit part of that analysis was not done before the RoHS directive was enacted. I have read the preamble carefully, and while I see vague allusions to benefits, I can find no claim that can be verified with publicly available data. Instead of documenting actual cases of poisoning by lead (and the other prohibited substances) that have occurred due to use in electronics, the directive's authors seem simply to have assumed that their use poses risks to public health. The precautionary principle puts the burden of proof on those who seek a change from prevailing practices. In this case, burden falls on the people who have asserted that substances must be prohibited. They have failed to provide even rudimentary proof. Of course, if the proof doesn't exist because the assertions are false, that is understandable.
For what it is worth, my training is in chemistry, and starting in 1999 I have conducted extensive investigations into whether the risk is real or imagined. There's no question in my mind that it's the latter. In fact, you will have a hard time finding any scientist or engineer who has been involved in helping the industry adapt to the directive who believes that the risk is real. They do what they are told to do because their employers are told what they have to do, but their heart is not in it. That aspect may not emerge from your questionnaire explicitly, but if you look for it in the responses, you may detect expressions of an underlying hostility toward those responsible for enacting RoHS. Those scientists and engineers have job security, to be sure, but most would have preferred to be engaged in an activity with some redeeming social value.
Despite a rigorous search I have been able to find not a single case of poisoning attributed to use of any of the prohibited substances in electronics. Did you know that blood lead levels have been dropping for decades since lead was removed from gasoline and paint? Did you know that the major sources of cadmium in people are food and cigarettes? Or that the major source of mercury in people is the burning of coal for power? So if you find that the costs are real and the risks are not, the analysis you publish should make it clear (if your client will allow you to tell the truth) that RoHS has been not a boon to society but a burden.
Before I would be willing to recommend the use a sharp pencil to document the cost impact of the RoHS directive on our company in completing your questionnaire, I would want some assurance that someone was conducting a parallel and sincere effort to, for the first time, document the actual environmental and health consequences of the use of the prohibited substances in electronic equipment. Actually, if that effort were made, and the results showed that there is no credible harm from the use of the prohibited substances in EEE, there would be little need for people to spend time completing your questionnaire to document the costs. Without effort those costs can be seen to run into the billions.