The TIM Blog serves as a clearinghouse for information relating to thermal interface materials including products, technologies, news, and events. We encourage comment and feedback on anything thermal interface material related.
With a sigh of relief, Christmas is over. The gift-giving anticipation is no more and I have walked away with a new tech gadget on my wish list. This was one that my sister received and I think is just great. It was a netbook. There are many types available, but these minimalist, inexpensive, tiny computers pack a lot into a small formfactor and for any function they lack, you can always plug in an external version as needed.
The netbook she received was adorable. The moment I saw it, I wanted to tear it down (but she was unwilling to let me). I couldn’t imagine how so much functionality including wireless connectivity, internet access, a webcam, ample storage space, and a card reader could be packed into such a small space without a thermal problem.
Talk about a potential cooling nightmare! In one tear-down website, it was made clear that spacing is tight, so the manufacturer opted for a fan, but not much else. I’ll be interested to see in the coming months whether a thermal issue in these netbooks arises. Have any of you had any problems with yours? I might have the thermal solution.
While it’s not the typical material of choice for thermal applications, bismuth alloys have found their place in this market with some unusual product designs.For this reason, we have decided to highlight this unique material.Check out the new bismuth website and hopefully learn a few things about these low temperature solders.
Before I read this recent article about the MacBook Air, I envied those who were able to purchase one of these trendy thin computers with the innovative marketing campaign.
I am reading now though that Apple, like so many have before, overlooked some thermal issues in their MacBook Air design and have had to issue a fix for some overheating issues they were having. Apparently, the fan in this computer has been underperforming and they have issued an update to the software so that it can be fixed.
In recent years, Apple has been known for their forward-looking approach with product testing that would typically notify them of any faults in their system. I guess this goes to show that even the best of us is struggling with overheating issues due to miniaturization. Luckily for them, the fix to their thermal issues seems to have been fairly simple.
If this remains the worst of the issues publicized on the MacBook Air laptop, maybe I’ll keep it on my Christmas wish list.
In many of the meetings I have had with customers or potential customers of indium material, I have been asked about the world supply of indium. This is a valid concern for those whose products are traditionally certified for decades, or for those who will purchase indium in high volumes and price fluctuations could harm. These customers need the re-assurance that the indium supply is sound.
Well, have no fear. The long-term supply of indium is both sustainable and reliable.
In fact, the abundance of indium in the earth is higher than silver, which is not considered in short supply. Additionally, indium containing mines have been discovered in numerous locations such as Portugal, Peru and China. Indium in the world today is plentiful and supply limitations should not become a problem.
Details on the world supply of indium and gallium were presented at the 22nd EU Solar Conference 2007 and the paper on this topic can be found here.
We’ve all heard of using liquid cooling in electronics.Liquid cooling is a common external cooling solution for devices as varied as personal computers, servers, or gaming systems.Have you heard of internal liquid cooling though?If liquid cooling from a distance works well, wouldn’t liquid in direct contact with the heat-generating source be even better?
Hardcore computer thinks so.
The thought of a liquid solution running over my PC components and circuitry makes me cringe.In their newly released Hardcore reactor desktop computer, Hardcore Computer is producing this product.
The Hardcore Reactor includes a patented liquid cooling technology.It includes an engineered fluid pumped through an interior cavity which includes the heat-generating electronic components. Hardcore Computer claims that the dielectric liquid technology disperses an order of magnitude more heat than air.
I’m not sold on this product though.
Some questions raised in the BetaNews article about this product made me wonder how good this cooling solution is:
Can the tower on this computer be turned over with the liquid inside?If not, how is the product shipped?
Will repair of the components in this product be possible?
The performance of the internal liquid cooling was compared with air, but how much better is it than external liquid cooling?
Liquid metals containing gallium are not simple to handle, but there are ways to do it, and anyone I know who has worked with these materials and handled them correctly, is pleased with the results they received.As explained in my previous post, the thermal performance of liquid metals is superior to all other commercially viable alternatives.
As a liquid metal with low flow stress, the liquid metal thermal interface materials are required to be specially packaged into an application to prevent leakage.Since gallium-containing liquid metals are corrosive to some materials and stick to others, the packaging materials must be carefully chosen.
A set of materials that I have worked with which were compatible with all the liquid metals are the Dupont Krytox products.There are a number of forms that these materials can be produced in, but the chemistry in any of these products makes them a good material fo r a dam surrounding the liquid metal.
These materials can be engineered for applications in both TIM1 and TIM2 applications.
Gallium is corrosive to aluminum. This picture was taken after gallium reacted with a sheet of aluminum foil. Image source: http://sci-toys.com/scitoys/scitoys/thermo/liquid_metal/liquid_metal.html
Liquid thermal interface materials are available in two forms:
metals liquid at room temperature
phase change metals
The major difference between the two is in the temperature which these alloys become molten.
Liquid metals remain molten at room temperatures. The following three liquid metal alloys become liquid at temperatures below 30 °C.
Phase Change Metals are applied in solid form and melt when exposed to heated junction temperatures. The most popular phase change alloy melts at 60°C.
– Indalloy 19 (51In, 32.5Bi, 16.5Sn)
The advantages to using these liquid metal thermal interface materials are many and include:
Extremely Low Thermal Resistance
The resistance obtained with the Indalloy 51 was tested to be less than 0.015 cm2-°C/W.
Metal in its liquid form has virtually no contact resistance
High Thermal Conductivity
As a completely metal thermal interface material, bulk thermal conductivity is premium
Ability to Withstand dramatic Thermal Expansion Mismatch
The low flow stress of liquid metals allow them to maintain surface contact while substrates pump during power or temperature cycling
Ultra Low Bondline Thicknesses
Liquid metals can be compressed to thicknesses below 0.001”
One difficulty encountered when using these alloys is the ability to contain them. All of the alloys which are liquid at room temperature contain gallium. Gallium is corrosive to various metals, especially when hot. As the temperature of the gallium is raised, it becomes increasingly corrosive, reacting through thicker layers in a short amount of time. One metal which gallium is very reactive with is aluminum. It will corrode through .002” thick aluminum foil within hours at room temperature, and at 500°- 1000°C, this reaction becomes much faster.
Gallium is non-reactive with other metals however such as molybdenum, tungsten, and nickel.
In addition to reacting with metals, gallium with also stick to non-metallic materials, making it difficult to package. Stay tuned for my next blog posting which will discuss packaging options for liquid metals.
Image taken by fellow Indium blogger, Anny Zhang when the leaves began to change last fall.
It is a beautiful time of year here in central New York.The weather is getting cooler and the leaves have turned from their summer green to vibrant shades of orange and red.In the northernmost areas, the leaves are already falling.
In contrast to the tranquility of this seasonal change is the feeling I have toward its outcome – raking leaves.I hate it and I dread it.Fallen leaves may seem harmless, but if left, they smother the grass and prevent sunlight from penetrating the grass during its fall growth season.
The way that I get through the leaves is the same way I’m going to push through this year’s fourth quarter rush.For those of you who experience it, you know that there is a lot to accomplish at the end of the year in a time period shortened by holidays and office gatherings.
On my own priority list I have thermal product evaluations to attend at customer sites, research paper deadlines approaching, internal thermal product testing to conduct, and industry conferences to attend. The only way to handle it is to do it a little at a time and stay on top of it.
Although the economy is struggling and everyone has their wallets tightly clenched, a survey released just yesterday reveals that customers are continuing to demand higher levels of customer service.These responses collected by Harris interactive should send an alarm to any company cutting customer service representatives to cut overhead.That strategy just might shoot you in the foot.Customers want support now more than ever.
Statistics from the survey:
58 percent of U.S. consumers said that in a down economy, they will always or often pay more for a better customer experience.
When recommending a company, outstanding customer service is more important (58 percent) than low prices (44 percent) and top quality products/services (43 percent).
In the past year, we have released and developed many new thermal products, compared them with our existing thermal products, as well as competitor thermal products. We have published much of this data and have already shared this data with many of you.
These accomplishments cannot be claimed by any one individual. The Indium thermal team is made up of a few and supported by many more. One of Indium’s greatest assets is the number of technologists we have at our disposal. We’ve got a team of experts who manage all aspects of thermal product concepts, thermal design and testing.
Our chemists are experts at formulating new materials.
Our process engineers have taken these formulations from theory and lab results to scaled-up products
Our application engineers have been extremely knowledgeable at matching existing materials to customer needs and transferring customer needs back to the research lab
Plus, we work closely with a specialized testing lab capable of conducting the most meticulous tests.
The result is a diverse, world-class team of scientists who are bringing to market the thermal products that customers need.
