Featured Research

from universities, journals, and other organizations

Improving the reliability of electronic devices by mitigating corrosive effects

Date:
January 18, 2014
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
A study of the thermodynamic properties of copper connections uncovers a route to improving the reliability of electronic devices.

A study of the thermodynamic properties of copper connections uncovers a route to improving the reliability of electronic devices.

One in five electronic-device failures is a result of corrosion. Bonds, the metal connections that enable the current to flow from one component to the next, are a particular weak point. Understanding what causes this breakdown is important for extending the lifetime of a device. Kewu Bai and co‐workers at the A*STAR Institute of High Performance Computing, Singapore, have charted how moisture can affect the stability of the bonding and developed a scheme for improving the reliability of these connections.

Wire bonding is generally considered the most cost-effective and flexible method for interconnecting an integrated circuit or other semiconductor device and its packaging. "This process uses force, ultrasonic vibrations and heat to make bonds," explains Bai. "The reliability of the bonds depends on the stability of the metallic compounds that form during the process of connecting a contact pad -- made from aluminum, for example -- and the wire, which is made of copper or gold."

Gold is the material of choice for electrical connections in microelectronic components. With the price of gold having steadily risen over the last few years, however, electrical engineers are now turning to copper as a cheaper alternative because it exhibits many of the same desirable electrical properties. As copper-aluminum compounds are prone to corrosion in humid environments, encapsulation is employed in microelectronic packages to prevent moisture ingress, yet permeation and leakage are still possible. Damage to the external packaging can allow moisture to reach the sensitive circuitry and slowly corrode the copper connections.

"Using simulations, we can understand the conditions for copper wire bonding corrosion in aqueous environments and the corresponding corrosion mechanisms," says Bai. "There has been much debate about the possible mechanisms for a long time."

Bai and his team calculated the thermodynamic properties of copper electrical bonds and used this information to construct so-called Pourbaix diagrams -- maps of the immunity, passivity and corrosion zones of alloys with different copper and aluminum compositions in the presence of corrosive agents, such as water and chloride at various temperatures.

"We showed that the stability of the layer of aluminum oxide formed during bonding plays a critical role," says Bai. "By introducing highly charged atomic impurities into the aluminum pads, the diffusion of aluminum atoms out of the aluminum oxide can be reduced and thus, the stability can be enhanced." Therefore, this scheme offers one possible route to improving the reliability of copper bonds.

The A*STAR-affiliated researchers contributing to this research are from the Institute of High Performance Computing


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Yingzhi Zeng, Kewu Bai, Hongmei Jin. Thermodynamic study on the corrosion mechanism of copper wire bonding. Microelectronics Reliability, 2013; 53 (7): 985 DOI: 10.1016/j.microrel.2013.03.006

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Improving the reliability of electronic devices by mitigating corrosive effects." ScienceDaily. ScienceDaily, 18 January 2014. <www.sciencedaily.com/releases/2014/01/140118122421.htm>.
The Agency for Science, Technology and Research (A*STAR). (2014, January 18). Improving the reliability of electronic devices by mitigating corrosive effects. ScienceDaily. Retrieved October 2, 2014 from www.sciencedaily.com/releases/2014/01/140118122421.htm
The Agency for Science, Technology and Research (A*STAR). "Improving the reliability of electronic devices by mitigating corrosive effects." ScienceDaily. www.sciencedaily.com/releases/2014/01/140118122421.htm (accessed October 2, 2014).

Share This



More Matter & Energy News

Thursday, October 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Japan Looks To Faster Future As Bullet Train Turns 50

Japan Looks To Faster Future As Bullet Train Turns 50

Newsy (Oct. 1, 2014) Japan's bullet train turns 50 Wednesday. Here's a look at how it's changed over half a century — and the changes it's inspired globally. Video provided by Newsy
Powered by NewsLook.com
US Police Put Body Cameras to the Test

US Police Put Body Cameras to the Test

AFP (Oct. 1, 2014) Police body cameras are gradually being rolled out across the US, with interest surging after the fatal police shooting in August of an unarmed black teenager. Duration: 02:18 Video provided by AFP
Powered by NewsLook.com
Raw: Japan Celebrates 'bullet Train' Anniversary

Raw: Japan Celebrates 'bullet Train' Anniversary

AP (Oct. 1, 2014) A ceremony marking 50 years since Japan launched its Shinkansen bullet train was held on Wednesday in Tokyo. The latest model can travel from Tokyo to Osaka, a distance of 319 miles, in two hours and 25 minutes. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Robotic Hair Restoration

Robotic Hair Restoration

Ivanhoe (Oct. 1, 2014) A new robotic procedure is changing the way we transplant hair. The ARTAS robot leaves no linear scarring and provides more natural results. Video provided by Ivanhoe
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins