Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Alloy developed at Sandia has potential for electronics in wells

An alloy that may improve high-temperature electronics in oil and geothermal wells was really a solution in search of a problem.
Sandia National Laboratories first investigated the gold-silver-germanium alloy about 15 years ago as a possible bonding material in a new neutron tube product. But a design change forced Sandia to shelve the material, said Paul Vianco, who has worked in soldering and brazing technology at Sandia for 26 years.

Then a few years ago, researchers working on other projects with applications inside a well, referred to as downhole, asked Sandia’s geothermal group to develop electronics to monitor well conditions in field operations. Circuit boards placed downhole in oil and geothermal wells must withstand high temperatures and pressures, excessive vibrations and other extreme environments.

The gold-silver-germanium alloy is suitable for those conditions, Vianco said.

It’s technically a solder, but it’s at the upper limits for what’s considered a solder — materials that melt at no higher temperature than 450 degrees Celsius (842 degrees Fahrenheit), Vianco said. The American Welding Society deems materials that melt at higher temperatures as brazing filler metals.

Sandia fills niche in downhole uses

The alloy’s potential for downhole electronics gives Sandia a unique niche, Vianco said.

Sandia National Laboratories researcher Tom Crenshaw sets up a specimen in a test frame that will pull a solder joint apart to determine its tensile strength. He co-authored a paper that won the Best of Proceedings category in the Surface Mount Technology Association’s International 2012 Best Papers conference. (Photo by Norman Johnson) Click on the thumbnail for a high-resolution image.

Most brazing processes occur at a peak temperature above about 700 degrees C, while most soldering occurs below 350 degrees C, leaving high-temperature electronics few filler materials from which to choose.

“So there’s this no man’s land in which the only materials that are available are aluminum-based brazing alloys that melt at about 600 degrees C,” Vianco said. But aluminum-based alloys are difficult to process for electronics.

In addition, the gold-silver-germanium alloy is lead-free, making it environmentally friendly for geothermal work in countries such as Iceland, which, like the rest of Europe, is moving away from materials that contain lead. The alloy’s fundamental mechanical and processing properties also are nearly fully characterized. That’s important because it saves about two years of development that would be required to establish how well the alloy makes a reliable solder joint, Vianco said.

“All that’s done,” he said. “We have the preliminary work completed that allows us to consider this material for a range of applications, including downhole electronics.”

Alloy developed from earlier work

The alloy originally was developed from the gold-germanium system, which has traditionally been a die attachment material used in microelectronics packaging. But a higher melting temperature was required for the neutron tube application, so Vianco and colleagues John J. Stephens, now deceased, and F. Michael Hosking, now retired, added silver and adjusted the concentrations to reach a near-uniform melting point for the alloy.

“It was so close to brazing that we didn’t think that there would be much interest in the electronics industry until the option came up for downhole applications,” Vianco said.

He is now seeking funds to develop the material to a prototype stage for geothermal and oil and gas well tools. “We really think it is a material that’s suitable for these higher temperature applications,” Vianco said. “In this no man’s land of filler metal technology, there are really not a lot of options out there other than lead-containing alloys. Companies are exploring lead-bearing solders, albeit begrudgingly so.”

When interest in downhole applications arose, Vianco and his colleagues needed to pull together information on the alloy from the mid-1990s. They resurrected the data and re-evaluated it, and Vianco wrote a paper assessing its properties.

That wasn’t as easy as it might sound.

“Photographs were all on film; we had to scan these pictures into an electronic format. Documents and presentations were in unusable formats or archived on software that is no longer supported by the labs.

So everything was brought up to a level that is compatible with current computer resources,” Vianco said.

Paper compiled research data

The paper, “Ag-Au-Ge Alloys for High Temperature Geothermal and Oil Well Electronics Applications,” won the Best of Proceedings category in the Surface Mount Technology Association International 2012 Best Papers conference announced in January. Vianco will receive the award at SMTA’s meeting in October in Fort Worth, Texas.

He wrote the paper largely to compile the data in case interest developed within the oil, gas and geothermal industries, and hadn’t planned to submit it for publication. But SMTA International, aware of Sandia’s leadership role in soldering technology, asked the labs to provide a paper for a session on alternative solders for electronic applications, so Vianco submitted it.

He believes Sandia might be able to use the gold-silver-germanium alloy as a joining material in high-precision components.

The paper and the publicity surrounding the award have raised awareness of the alloy and the growing need for high-temperature materials to support downhole electronics, Vianco said.

“This is how tech transfer works the best — publish the material and let the folks who have the need become aware of it and then work with their specific applications,” he said.

Sandia National Laboratories is a multiprogram laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.

Sandia news media contact: Sue Holmes,, (505) 844-6362

Sue Holmes | EurekAlert!
Further information:

More articles from Power and Electrical Engineering:

nachricht Greater Range and Longer Lifetime
26.10.2016 | Technologie Lizenz-Büro (TLB) der Baden-Württembergischen Hochschulen GmbH

nachricht 3-D-printed magnets
26.10.2016 | Vienna University of Technology

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Greater Range and Longer Lifetime

26.10.2016 | Power and Electrical Engineering

VDI presents International Bionic Award of the Schauenburg Foundation

26.10.2016 | Awards Funding

3-D-printed magnets

26.10.2016 | Power and Electrical Engineering

More VideoLinks >>>