Thermoelectric Cooling Solutions
External Cooling Concept
TO56/TO9 Laser Diode
(or similar object)
Final product item
(packaged assembly
on a header)
Heatsink
TE Cooler
(Cut view)
Thermal
Contact area
“External” TE Cooling
TEC cools the entire
assembly
Heatsink
Heatsink
Center Hole
for LD wires feed
through
Heatsink
“Internal” TE Cooling
TEC on a header, cools the
heat-generating object directly
Description
“External cooling” with center-hole thermoelectric coolers is the solution for objects without a possibility to integrate
TEC inside (or where a built-in TEC is not sufficient enough because of large heatload). For example there is a wide
range of uncooled LD types that use industrial standard TO-56 or TO-9 headers. The typical design and pins
layout for such headers assume uncooled solution with no space to integrate a thermoelectric cooler directly on a
header. In the same time thermal stabilisation can improve LD performance and lifetime and give additional features
in final application. In such cases the “external” thermoelectric cooling can be an optimal choice. TEC has a center
hole (or multiple holes) to feed LD pins through and provide a thermal contact between header and cold side
surface. Center-hole TECs and “external” cooling are optimal for creating environmental testing setups for LD
manufacturers, laboratory researches and temperature sensitive experiments.
Application Tips
1. An appropriate heatsink is required to be attached to TE cooler hot side. TEC operates as a heatpumt. The heat
pumped from TEC cold side has to be spreaded from a hot side with a heatsink.
2. TEC built it on a header (internal cooling) is more optimal solution by power consumption comparing with
“external” one (TEC under the header). The external cooling is good if there is no way to intergrate a suitable TE
cooler on a header. The external cooling can be an extension for standard un-cooled packaged devices.
3. With the external cooling the temperature on TEC cold side may differ from temperature of the object inside a
packaged assembly. This is a result of header thermal resistance availability.
4. Recommended methods of mounting: thermal grease or gluing. In case of Copper or Aluminium heatsink
materials it is strongly recommended to use a thermal grease or elastic silicon-based thermoconductive glues.
Copper and Aluminium heatsink materials have high thermal expansion coefficient (CTE), different to TEC
materials.
46 Warshavskoe shosse. Moscow 115230
Russia,
ph: +7-499-678-2082, fax: +7-499-678-2083, web:
www.rmtltd.ru
Copyright 2012. RMT Ltd. The design and specifications of products can be changed by RMT Ltd without notice.
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