Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Alloy developed at Sandia has potential for electronics in wells

20.03.2013
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, sholmes@sandia.gov, (505) 844-6362

Sue Holmes | EurekAlert!
Further information:
http://www.sandia.gov

More articles from Power and Electrical Engineering:

nachricht System draws power from daily temperature swings
16.02.2018 | Massachusetts Institute of Technology

nachricht Researchers at Kiel University develop extremely sensitive sensor system for magnetic fields
15.02.2018 | Christian-Albrechts-Universität zu Kiel

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: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>