Thin-film cooler firm gears up for production
Nextreme Thermal Solutions will take a first step towards mass-production this year, as it nears its goal of bringing thermoelectric cooling to high-volume electronics manufacturing for the first time.
A $13 million venture capital investment in August has helped the company bring an additional MOCVD reactor online in anticipation of production ramps later in 2009.
Initial volumes are rolling out of the company's Durham, North Carolina facility as its customers assess the suitability of the thin-film bismuth telluride-based devices for their own products.
“Customers are using those to evaluate the technology, to look at designing us in and then beginning to place orders,” said Paul Magill, Nextreme s vice president of marketing and business development. “We ve had a few orders placed for qualification.”
“We would expect that we ll begin to see some production orders based on those qualification cycles in the second half of the year.”
Heat flux in thermoelectric coolers (TECs) is inversely proportional to semiconductor film thickness, a fact that Nextreme s ability to produce micron-scale bismuth telluride layers via MOCVD exploits.
So, although TECs are perhaps most widely deployed for cooling diode lasers, Nextreme s thin, high-flux variety is also attracting attention from beyond this sector.
“Intel is very interested in the technology, although we still need to improve it a little bit,” Magill said. Nextreme partnered with the silicon chipmaking giant to demonstrate a 1300 Wcm-2 heat flux from a silicon chip package in a Nature Nanotechnology paper published on January 25.
Magill points out that Intel chose to produce its current dual- and quad-core processors partly to avoid the formation of “hotspots” that would have formed if it pushed its previous architectures to higher speeds.
“But you can only do so many cores, and each one of those cores will eventually have a hotspot if you want to keep pushing more processing power through it,” he said. “So they are still keenly interested in this technology.”
Fitting in
Intel, Casio, contract electronics manufacturer Amkor and others all use a high-volume copper pillar bumping manufacturing process that Nextreme says its TECs readily integrate into.
This integration has been further boosted after Nextreme recently moved its cooler technology from operating at 1V and around 4A, to 3V and less than 1A. This avoids the need for voltage conversion in volume manufacturing. “These devices are now compatible with the kind of currents and voltages that you d find in printed circuit boards or in most electronic devices,” Magill said.
When he joined Nextreme in 2006, Magill saw around 5 monthly enquiries into the company s technology. That has increased to around 70 more recently, and as many as half of these are interested in power generation.
While applying current to Nextreme's TECs produces cooling, the company also makes thermoelectric generators that convert temperature differences to current.
The number of applications this could be exploited in is diverse, but Magill raised power production in automobiles as a particularly high profile one.
“Automobiles basically only convert only 25 percent of the gasoline that s burnt to movement,” he pointed out. “The rest of the energy just goes off as waste heat.”
“So we essentially have these open furnaces running around the country, and there's a great opportunity here to do energy scavenging.”
