How to select Thermo-Module

Selection of Thermo-Module and Determination of Operating Parameters

For 12W of heat load , it is expected to keep -3°C at low temperature side of single module(Tc). The hot side temperature (Th) is supposed to be kept at 50°C by using a proper heat sink.

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Thermal Resistance and Temperature Distribution

When a certain Object is cooled with thermoelctric module, the temperature distribution is shown in Figure3. It is neccesary that the cold side temperature(Tc) is lower than the cooled object, because the thermal resistances such as greased, adhered, or soldered interface exist between the cold side ceramics and the cooled object. And also the hot side temperature(Th) is higher than heat sink temperature, becasuse there are simular thermal resistances between the heat sink and the hot side ceramics. If a comparison is made between junction and such heat dissipating media as air or water, the temperature difference would be much larger. Depending on the area and cooling method (natural air, forced air, water ) of the heatsink, thermal resistance greatly varies. Furthermore, thermal resistance also greatly depends on flow rate of the media. For further information, please contact our technical department.

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How to Use Thermo-Module


1) Handling

a) Vibration and Shock
The thermoelements of thermo-module are weak materials to mechanical shock. Please handle it in ceramic parts to avoid damages to thermoelements. Please do not use thermo-modules which dropped, because it may be damaged.

b) Machining
Please do not do machining to thermo-module

2) Instllation of Heat sink.

Please be sure to install a heat sink in hot side. The assemble solder of thermo-module would melt and the module would break without a heat sink.
Please select heat sinks according to the heat generation. The heat generation is calculated as follows.

Qh:Heat generation at hot side(W)
P:Erectrical input power(V × I)(W)

3) Installation

a) Multi-purpose Module
Generally, the thermo-module is fixed with screws by setting up the boards in the top and bottm of it.The surface pressure at fixed is 0.2~0.5Mpa is appropriate. Please install carefuly with no partial loads.
b) Telecom Grade Thermo-Module · Multi-Stage Module
When thermo-module is attached to heatsink plate with solder or adhesive, please select the CTE(Coefficient of Thermal Expansion)of the heatsink plate connected to thermo-module near the CTE of ceramic substrate of thermo-module to reduce the stress of thermal deforamation. When it is unclear, please contact us.

2.Caution in Use

1) Polarity of Thermo-Module
Please confirm the polarity before use. The right lead is the plus when module is set the lead wires attached ceramics down and you look module from lead side.( Refer to Fig.4

2) Current
DC current should be used and ripple content of 10% or less is recommended.

3) Dewfall Prevention
Please do the dewfall prevention measures when it is used in the dewfall environment. We prepare modules with the epoxy seal as dewfall prevention in the multi-purpose module.

4) Instllation Temperature
Please use it in module temperature less than 85°C. Performance of thermo-module degrades when used in a high temperature for a long time.