The ‘Passive’ Approach to RoHS
By John F Mason -- EDN, July 21, 2006
Think the European Union’s RoHS directive has affected everyone in the supply chain at the same level? Think again.
“The EU Commission’s RoHS-compliance deadline of July 1, 2006, banning the use of six hazardous substances in electric and electronic products, has not made much difference in the way we at Epcos AG operate,” said Dr. Gerd Schulz, global coordinator of Epcos EH&S and radiation protection. Epcos, headquartered in Munich, Germany, evolved from a joint venture of Siemens Matsushita Components in 1999.
“As a manufacturer of passive components we are not actually bound to the demands of the RoHS directive. We are simply required to provide our customers with compatible components that fit their specific RoHS-compliance needs. Nevertheless, we have been moving toward RoHS compatibility since 2001 -- getting greener by the month while continuing to develop, manufacture and market passive electronic components for IT and telecommunications, for automotive, industrial, and consumer electronics. An impressively broad product portfolio and truly global presence have made Epcos the market leader in Europe and number two in the world.”
As is well known among users, passive components differ from active components in that they have no impact on the electrical signals or the data that pass through them. Only when you apply voltage is there a flow of electric current. Examples are resistors, capacitors and inductive components.
Active components, on the other hand, add intelligence in some manner to the signal or data that pass through them. For example, in networking, an active hub regenerates fading input pulses into new, strong output pulses. In contrast, a passive hub is just a junction box that does not affect the passing data.
“Epcos, at this moment,” Schulz continued, “offers more than 35,000 RoHS-compatible products: aluminum, electrolytic capacitors, film capacitors, inductors, ceramic components, surge arresters, SAW components and ferrites. We finished the transition long before July 1, 2006.”
As for completely phasing out lead, there are some lead-based components used by companies that are exempt. “We will nevertheless phase out lead wherever possible. But there are still applications, for example for heavy tools, the military and the automotive industry that need leaded components. These components which are produced only for these branches of the industry will be transposed later. But we will not produce the same product RoHS and non-RoHS compatible side by side,” he said.
Schulz further noted that the company considers RoHS 5 compliance to be unnecessary (all regulated substances are below the maximum concentrations values published by 2005/618/ec, but not lead). The concept was created by the telecommunications industry for cases of RoHS exemption number seven, point 2. “We are concerned only with 100 percent RoHS compatibility and not with RoHS-5 or variations of the same,” he said.
Epcos’ worldwide market is big because passive electronic components are used in nearly all electrical and electronic devices. A single car can contain as many as 10,000 such components. In mobile phones and lighting ballasts, notebooks and electric locomotives, passive electronic components are instrumental in processing electrical signals, protecting electronic circuits, and ensuring a regular, reliable power supply.
A number of directives define the restrictions for substances used in electrical and electronic equipment. Experience made it clear to that it was not possible to replace the banned substances in each application. At an early stage before the RoHS had been enacted, members of the Association of the German Electric and Electronic Industry (ZVEI) approached the Commission to ask for two important exemptions for passive components concerning lead content and an exemption for the use of lead with flip chip packages. Meanwhile, 20 exemptions had been granted with the Annex of the RoHS and its amendments directive 2005/717/EC from October 15, 2005, directive 2005/747/EC from October 25, 2005, and directive 2006/310/EC from April 28, 2006, while others are pending.
“RoHS has become a very complicated peace of legislation, in respect to market surveillance,” Schulz commented. “Lead has been the major issue with the RoHS transposition. But we have for some time, and will continue to, phase it out wherever possible. Lead still has its uses in, for example, heavy tools, the military, and the automobile industry that need leaded components. Components produced only for these branches of the industry will be transposed later.
“There has been a great deal of costs for all these changes -- in materials and in manufacturing procedures,” Schulz said. “Fortunately about 60 percent of our products had already been RoHS compatible since the start of production; for all others the plating of the terminals or internal solder connections had to be replaced.”
He noted that all of the parts had been qualified to withstand the higher temperature requirements of the lead-free soldering processes. The result, in some cases, was an adaptation of materials, and in other cases an adaptation of the layout. Only in one case, a cadmium containing ceramic paste, was a component replaced with a RoHS-compatible one.
“There were lots of processes to be handled, like monitoring hot dip tin bathes for lead contamination, implementation of additional regulations within the management systems, and satisfying all the individual requirements of our customers -- one being the declaration of materials and RoHS compliance, sometimes including analytical tests; also technical qualifications and testing,” Schulz said.
“And there are `side effects´ to RoHS. I spend a lot of time as chairman of several committees and working groups dealing with RoHS-related issues, like standardization and lobbying or actively assisting working groups for RoHS implementation.
“All in all it has not been an easy process and I sometimes personally wonder if we are really benefiting the environment,” Schulz questioned. “For example: Lead-free soldering processes are consuming roughly 30 percent more energy than the leaded processes. Do we shift the lead problem from lead to CO2 emissions? What about the environmental impact of the substitutes, like silver and copper, used with the new solder materials?”
