U.S. lags in regulation of lead in electronics

Despite legislation banning lead in paint and gasoline, the United States lags behind when it comes to restricting the use of lead in electronics.

The metal ‘glue,’ or solder, that holds many electronic circuit contacts together was traditionally made out of a tin-lead alloy. Solder is used commonly to join two metal contacts together at a temperature lower than their melting points. This allows electrical connections to be made without disrupting the form of the pieces being connected, which may cause malfunctions.

 Under certain conditions, the lead in electronics that have been thrown away can leach into groundwater. If high concentrations build up in the water that people are drinking, people can become sick with lead poisoning. High accumulations of lead can also affect the environment. Besides contaminating the soil, animals and plants, like humans, can also suffer lead poisoning.

 There are lead-free solders available on the market today, but the United States isn't forcing companies to use them for consumer products. Even though other countries have already implemented bans against lead in solder the United States has passed no legislation on the subject.

"I'm disappointed in my country, trying to be the tail that's wagging the dog right now," said Iver Anderson, a senior metallurgist at the U.S. Department of Energy's Ames Laboratory and co-inventor of a popular lead-free solder.  Anderson further explained that the United States relies on Europe for legislation that bans lead-based solders without implementing any laws against use of the same type of solder at home.

 "On July 1, 2006, all electronics sold in Europe had to be made with lead-free solder," said Anderson. This was part of two European directives: the WEEE  (Waste Electrical and Electronic Equipment) and the RoHS (Restriction of Hazardous Substances) legislation. Together these directives work towards restricting the use of certain hazardous materials, like lead, in electronics, backing up environmental awareness with real enforcement.

 After the July 2006 date, companies wanting to sell electronics in Europe, no matter where these companies were based, had to use lead-free solder to assemble their products. "Nokia (based in Finland) was probably the first company that went lead-free, in their line of cell phones.” said Anderson.

Image

Besides being used in computers, cell
phones and other electronics, solder can
be found in other products like stained
glass windows, plumbing pipes,
automobiles and airplanes. The use of
solder goes back thousands of years to
the knights and their armor, but the main
purpose of solder, which is to connect two
or more, usually metal, pieces together,
hasn’t changed. Photograph by Kathryn
Bobolinski.

 Japan is another country where many major electronics companies, like Sony, were working to go lead-free, beginning in 2000. This decision was largely voluntary, really a shrewd commercial/marketing move, along with showing environmental enlightenment, since Japan has no legislation on the matter.

 Many of the lead-free products are sold into the United States from the global electronics producers, but there is no current guarantee in the US that your cell phone, for example, does not contain lead.

 "Producers [of electronics] want to sell their product all around the world," said Anderson. He cited this point as a major reason why most electronics in the United States do not contain lead-based solder.

 Some legislation in the early 1990’s that tried to restrict the use of lead in solder was proposed to the U.S. Congress, e.g., the Reid, Cardin and Bradley bills, but none of the bills became law.

 Anderson said even though lead-based solders are currently allowed in the United States, the U.S. military is attempting to take lead out of their electronics to set an environmental example and to have access to less expensive commercial systems that are produced throughout the world.  Anderson has collaborated with Rockwell-Collins, a company located in Cedar Rapids, Iowa, specializing in aerospace and defense products, to take the lead out of their solders. This is because they also are a globally competitive company that desires a market reach beyond the US borders with both military and commercial products.

 Anderson is leader of a team at the Ames Laboratory that worked on discovery of a novel lead-free solder and continues to develop improvements.

 “First we took lead out of paint, then we took lead out of gas, and then we thought now let's take lead out of solder, and people thought 'well that's impossible,’ ” Anderson said, but we did it.

 The lead-free alloy the Ames Laboratory team discovered is a mixture of tin, silver, and copper, which turned out to be both easy to work with and noticeably stronger and more heat resistant than traditional lead-based solders. Patented in the United States in 1996 and 2001, Ames Laboratory’s lead-free solder is currently licensed to more than 60 companies around the world.

 Expense has been one of the major constraints concerning lead-free solders. Lead-based solders are inexpensive, and lead-free solders have a hard time competing on cost.  But unlike some other lead-free solders that have been developed, the Ames Laboratory alloy is relatively inexpensive.  In recent years, the change from film  to digital in cameras has also made silver cheaper because it was used in some of the chemicals needed to develop film.

 One industrial team that competed with Ames Laboratory’s scientists to make a lead-free solder developed a tin-indium-silver alloy.   Even though the solder worked well in several joining applications, indium is an expensive and rare element and this solder has not succeeded due to cost. “The reason indium is becoming increasingly scarce is because it goes into every plasma TV,” said Anderson.

 Anderson summed it up by saying, “Will we still be able to use our tin-silver-copper solder in 20 years? The answer is ‘yes.’ ” He explained that the minerals mined or recycled (copper and silver) for the Ames Laboratory solder are relatively plentiful and will still be around for the foreseeable future.

 Currently, work is being done to make the Ames Laboratory lead-free solder perform even better than traditional lead-based solders. To do this, a fourth element is being added to the copper-silver-tin alloy. Testing is being done with zinc, aluminum and magnesium. Adam Boesenberg, a graduate student in the Material Science and Engineering department at Iowa State University, is one of the latest team members working on this issue.  He presented his ideas and findings at The Minerals, Metals & Materials Society (TMS) Annual meeting in San Diego, California that was held February 27 through March 3, this year.