The European Union (EU) has established a deadline of July 1, 2006, for manufacturers and vendors of electronics equipment to comply with directives that ban more than trace levels of lead, hexavalent chromium, cadmium, mercury, polybrominated biphenyls, and polybrominated diphenyl ethers from the new electrical and electronic systems sold within its member states. The directives exempt military equipment and other classes of systems deemed essential to the public welfare for which no suitable substitutes for such substances can be found. However, the new rules will have a major effect on a wide range of electronic equipment, including office communications devices such as fax machines and telephones. Even equipment developers working in exempt areas such as telecommunications networking equipment have moved to comply with the directives-which has given optical-component vendors something to think about.
The EU directives, dubbed Reduction of Hazardous Substances (RoHS), have served as a catalyst for other countries to enact similar guidelines. For example, Japan and China have established rules that mirror the RoHS directive. Therefore, the trend toward “green” technology represents a significant market trend.
For the optical communications industry, the lead used in industry-standard tin-lead solders represents the most significant potential offender; older printed circuit boards contained some of the other substances but have since moved to more eco-friendly materials.
The good news for the developers of optical transceivers and ICs is that a recent study commissioned by the EU has confirmed the exemption for the use of lead solders in servers, storage, and storage-array systems as well as network infrastructure equipment for switching, signaling, transmission, and network management.
“There are good technical reasons for [the use of lead solders in such equipment] to be exempt, at least temporarily,” offers Dr. Paul Goodman of the Reliability & Failure Analysis Group of ERA Technology (Surrey, UK), which performed the study. The first criterion for exemption is whether the failure of the equipment in question would present a risk to public safety; the public phone system clearly passes that test, Goodman says. The next consideration is how likely such a failure would be if existing alternatives were used instead of the hazardous materials. “There are concerns over the long-term reliability of lead-free solders,” reports Goodman. “They haven’t been used very many years yet, whereas tin-lead’s been used for decades.”
Goodman notes that his investigations have turned up conflicting reports on the reliability of lead-free solders versus tin-lead. The fact that most studies into the matter have used accelerated life testing calls their results into question. Therefore, he recommended to the EU’s Technical Adaptation Committee that the exemptions for leaded solder in such equipment-and in the components that compose them-remain in place. The committee accepted the recommendation, and the exemptions are expected to be part of the final set of directives that will be put before the European Parliament later this year.
Despite the exemption, optical-component and manufacturing services suppliers say their customers have begun to request RoHS-compliant products. One reason is the exemption isn’t expected to last forever. Goodman’s group recommended that the exemption remain open ended, since the directive states that the EU is supposed to review all exemptions every four years. (No mechanism for such review currently is in place, he admits.) The other reason, sources say, is that some systems vendors may use RoHS compliance as a product differentiator.
“The move to no-lead is being largely driven by markets, rather than the need to reduce pollution,” says Paul Magill, CTO and vice president of business development at design and manufacturing house Avo Photonics (Horsham, PA). Avo has developed a lead-free thermoelectric cooler (TEC)-to-package process. “What’s most important is that whatever solution you use to replace the existing process is as reliable and as cost-effective. And that’s not always so easy.”
Most lead-free solders melt at higher temperatures than the common tin-lead solders. Some also suffer from “tin whiskers,” growths that could cause closely spaced components to come in contact with each other. Thus, the challenge is to find a lead-free solder that is both effective and can be applied without frying sensitive components during the melting process. Avo uses a gold-tin solder, while other vendors report using a combination of silver, copper, and tin.
“The solder options are still kind of up in the air,” says Mike Fukatsu, director of sales and marketing at OE Solutions America (Santa Ana, CA). “There is still a lot of concern about the tin-whisker problem when you use some of the silver-tin-type solders. I think a lot of it is going to end up coming down to experimentation.”
Fukatsu says that systems customers targeting the Japanese PON market have already begun requesting lead-free transceivers. Therefore, OE Solutions plans to have lead-free devices available in the second half of this year. “It’s easier for a company like us, since we’re a relatively new startup and our products are mostly newer technologies. So we’re doing SFP and things like that,” he reveals. As far as companies with more established lines, “the big question I think for the industry is do they have to go back and redesign all their old products to comply with [RoHS]?” he asks.
At Optical Communication Products (OCP-Woodland Hills, CA), planning a RoHS strategy began in the directive’s early days, before the 2010 expiration date on the exemption for servers and related equipment was removed. The company quickly saw the wisdom of making its next generation XFP and SFP products with lead-free solder, according to OCP marketing director Kirk Bovill. “They’re the new things now, and they’re going to be here way beyond 2010. So you want to have those RoHS-compliant,” he explains. Legacy form factors are perhaps another story, however. “All your old through-hole stuff, your SFFs, your 1×9s, your GBICs-pretty much that technology you would assume within five years from now would be next to nothing because it would be replaced by all these new designs,” Bovill says. “Why would I spend the money to go redesign a bunch of products that are 10 years old that are on their end of lifecycle anyway? Because it’s not a cheap thing to do.”
Some bigger players also have established their willingness to meet the RoHS directives. At OFC/NFOEC in March, both JDS Uniphase (San Jose) and Agilent Technologies (San Jose) announced lead-free product lines. Leland Day, manager, PLM and marketing, of JDSU’s Datacom Business Unit, agrees with OE Solutions’ Fukatsu that the Japanese market is leading the push for RoHS-compliant products.
Meanwhile, Tom Fawcett, marketing manager for fiber-optic products within Agilent’s Networking Solutions Business Unit, says his company’s complete transceiver line will be RoHS-compliant by the end of the year. Interestingly, Agilent will start with its legacy products such as GBICs and 1×9 devices. He expects there will be no price difference between the lead-free products and their predecessors.