The Thermal Management Group from CUI announced today a new line of Peltier TEC (thermoelectric cooling) modules. The brand claims that their arcTEC™ structure makes their modules unique among TECs.
In classic Peltier devices, semiconducting materials with differing electron densities (doped to be either positive (P) or negative (N)) are placed in series. On either side of the semiconductor “pellets” are layers of copper which is, in turn, covered by a layer of ceramic.
When voltage is applied to the semiconductors, current crosses between the pellets and generates a temperature difference. The hot side is attached to a heatsink, allowing the cool side to produce temperatures up to 70°C cooler than the hot side.
A representation of a Peltier device with CUI's improvements included. All images used courtesy of CUI
A close-up of the layers.
Aiming to Improve on Traditional Thermoelectric Coolers
According to CUI, their new modules differ from the average Peltier devices in their use of a conductive resin layer. In arcTEC devices, the resin is placed on the cold side of the TEC, between layers of copper and ceramic.
The resin’s elasticity accommodates for the expansion and contraction that naturally occurs with temperature changes. CUI claims that this gives components more longevity and allows better thermal connection overall.
On top of this use of resin, CUI also claims that they’ve increased the temperature resistance of the solder used in their TECs, moving from BiSn solder (with a 138°C melting point) to SbSn solder (with a 235°C melting point). They’re also touting their larger P/N silicon semiconductors which reportedly improve the uniformity of cooling.
A comparison of temperature distribution seen between a traditional Peltier TEC and one with arcTEC structure.
The new line includes five different series of modules: CP20H, CP30H, CP39H, CP60H, and CP85H. All use the arcTEC structure, have current ratings between 2.0 A and 8.5 A, and can have a ∆Tmax of 77°C (Th=50°C).
CUI suggests that these modules are best used in medical and industrial applications or sealed environments where forced-air cooling methods aren’t possible. This is in-line with the use of standard TECs, which are excellent for applications where maintenance is difficult due to their solid state nature. This does come at the cost of efficiency, compared to other cooling systems (such as vapor compression, magnetic, or thermionic systems).
You can read more about the arcTEC structure in CUI’s arcTEC application note (PDF).