Tag Archives: semiconductor

New Qpedia Thermal eMagazine Published!

Qpedia Thermal eMagazine, Volume 6, Issue 11, has just been released and can be downloaded at: http://www.qats.com/Qpedia-Thermal-eMagazine/Back-Issues. Featured articles in this month’s issue include:

Honeycomb Heat Sinks for LEDs

LEDs, or light-emitting diodes, are a form of solid-state lighting. An LED light is often made of a small piece of semiconductor, an integrated optical lens used to shape its radiation pattern, and a heat sink, used to dissipate heat and maintain the semiconductor at low operating temperature. LED lights present many advantages over incandescent light sources, including lower energy consumption, longer lifetime, improved physical robustness, smaller size and faster switching. This article examines Ma et al’s  findings with respect to the honeycomb heat sink design employed in LEDs, which has proven to be highly efficient.

Characteristics of Thermosyphons in Thermal Management

With the increase of heat fluxes and shrinking chip sizes in electronics applications, there is a need to spread the heat from the small chip to the larger heat sink or to transport the heat to a location where there is ample space to remove the heat. Heat pipes, vapor chambers and thermosyphons have been introduced to undertake this task and, in this article, we focus on some aspects of the design of thermosyphons. The advantage of thermosyphons is that they have no capillary limit and can transport large amounts of heat over long distances.

Industry Developments: Heat Pipes Providing High Performance

Heat pipes are increasing in type and use for the benefits they provide. Because of their lower total thermal resistance, heat pipes transfer heat more efficiently and evenly than solid aluminum or copper. Heat pipes contain a small quantity of working fluid (e.g. water, acetone, nitrogen, methanol, ammonia). Learn the conclusions of a recent study that focused on the best working fluid and another study of heat pipes in outer space.

Technology Review: Cold Plates, 2010 to 2012

Qpedia continues its review of technologies developed for electronics cooling applications. We are presenting selected patents that were awarded to developers around the world to address cooling challenges. After reading the series, you will be more aware of both the historic developments and the latest breakthroughs in both product design and applications.

Cooling News featuring the latest product releases and buzz from around the electronics cooling industry.

Download the issue now.

Not a Qpedia subscriber? Subscribe Now for free at: http://www.qats.com/Qpedia-Thermal-eMagazine/Subscribe-to-Qpedia and see why over 18,000 engineers read Qpedia.

2013 Webinar Calendar Released

ATS will provide two free technical webinars each month in 2013. Presented by PhD-level thermal engineers, each event will focus on an important area of electronics thermal management. The tutorials will provide practical training and insights for all engineers, designers and program managers who want to learn more about electronics cooling.

Most of the ATS webinars are scheduled to run no longer than 15 minutes in respect to the time demands on todays engineers. But each quarter of 2013 will conclude with a one-hour event that presents deeper training on a crucial heat management topic.

Every webinar is free of charge. Attendees can submit questions during the live presentations. For later viewing, each webinar will be archived on the ATS website for free streaming at the engineers convenience. Questions and comments to the recorded webinars will be responded to by ATS engineers.

ATS Webinars

Here are the 2013 ATS webinar dates, run times and titles:

Jan 9: What is the Thermal Management of Electronics?

Jan 23: Thermal Interface Material Overview: Pros and Cons

Feb 13: Calculating Junction Temperature in Electronics Cooling

Feb 27: Important Factors When Doing Heat Sink Design

Mar 13: Analytical Modeling for Thermal Analysis

Mar 27: Heat Sink Materials: Choices and Tradeoffs

Apr 10: LED Cooling: Whats So Hot about LEDs?

Apr 24: LED Cooling: Analytical Thermal Analysis

May 8: LED Cooling: Computational Thermal Analysis

May 22: LED Cooling: Physical Thermal Analysis

Jun 12: Heat Sink Fin Spacing for Heat Transfer Optimization

Jun 26: Temperature Measurements Within Electronic Systems

Jul 10: Heat Sink Types: Pros and Cons

Jul 24: Heat Sink Manufacturing Processes

Aug 14: Thermal Conductivity: What It Is and Why You Should Care

Aug 28: How to Perform Pressure Drop Calculations

All webinars are on Wednesdays at 2pm. Please visit www.qats.com/training to view the entire list of webinars, on-demand webinars in the archive, and to register for the full hour, live tutorials.

ATS Case Study: Improving temperature control of Automatic Test Equipment

Lab Equipment
We wrote about “Thermal Management of Testing High Power IC Devices” last week and noted that ATS’s team had been approached to invent a cooling test head for semiconductor test equipment. We thought our readers might like to hear a bit more about that project.

A major semiconductor firm focusing on the network processors approached ATS to consider how improved temperature control of test could be implemented for their existing automatic test equipment test head. ATS proposed to redesign the existing test head to allow for improved processor temperature control during the test cycle. While the project never went forward, the thermal design approach for this kind of thermal challenge is useful to consider.

Semiconductors aren’t likely to get cooler and automatic test equipment needs to be designed to handle the potential extremes in thermal states such components go through during test.

As part of ATS’s evaluation of the project, we discovered that the test head only maintained one fixed temperature and did not compensate for the power being dissipated by the device under test. During the customer’s test, the device power level changes greatly as it cycles; especially at power up the device made a very rapid ramp.

The overall purpose of the test head is to control the processor temperature to a known value with reduced variation, independent of the instantaneous power level. ATS’s proposed two different appraoches to solve the problem of the test head being now required to compensate for the power being dissipated by the device under test.

The first approach suggested was to reduce the thermal mass and decrease the latency in both heating and cooling of the processor. Reducing the thermal mass required a very detailed study on the power signature of the test cycle to anticipate the required cooling (or heating) at a given point of the cycle. ATS felt this method could offer the potential for a tighter control of processor temperatures while requiring more complication control hardware and precise understanding of each test cycle.

A second approach our team suggested was to increase the thermal mass of the system to dampen the temperature variations caused by the power level fluctuations. The increased thermal mass would help to absorb the power impulse levels while keeping the temperature relatively steady through the cycle. The advantage of this approach is that it would require less sophisticated control and monitoring hardware, and not be as process dependant.

Thermal management is a necessary evil (or obsession if you live in our world) and it has to be addressed at many different levels. And this includes the thermal management of test equipment during test.

For more information about Advanced Thermal Solutions, Inc. (ATS) thermal management consulting and design services, visit https://www.qats.com/consulting or contact ATS at 781.769.2800 or ats-hq@qats.com.