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Thermoelectric cooler applied in the LED packaging

Time: 2015-06-03 16:58:05    Click: 415

LED is a kind of solid semiconductor lighting devices. Similar with traditional light source, during work, the solid light source will generate heat because of current flowing in the diodes. As long as the current flows continuously, the heat will continue to be produced. The node temperature of LED must be below 125℃. The high node temperature will bring many adverse effects, such as the quantum efficiency of LED reducing, the luminousefficiency declining, the peak wavelength shifting and ser...(more)

The heat resistance theory of heat sink

Time: 2015-05-29 11:20:28    Click: 313

As shown figure 1, the heat flow _0 goes through the bottom of heat sink and then goes into its root. In the root, the heat flow will be divided into two shares _1and_2, and then through the root and environment air, start convection and heat exchange. Finally, the heat flow goes into the environment by heat exchange with fins. The heat resistance network model is shown in figure 1. Fig 1. The heat flow schematic diagram of heat sink dissipation Fig 2. The heat resistance network model of fins A...(more)

The structure of thermoelectric cooler

Time: 2015-05-29 11:12:17    Click: 265

Thermoelectric cooler (TEC) is built on the Peltier effect. Due to the internal structure features of semiconductor material, it has more obvious thermoelectric effects than other metals do. Therefore, semiconductor material is usually used for making TEC . The cooling capacity of a pair of couple, which consists of P-type and N-type semiconductor, is fairly small. For example, the cooling capacity of the couple (6mm 7mm) is only 0.92~1.16W. In order to obtain more cooling capacity, many pairs o...(more)

The soldering of TECs in Thermo-electric Cooling System (II)

Time: 2015-05-29 11:00:38    Click: 201

(c) Use proper pre tin in the soldering area of the surface of the heat sink . Thus, the melting point of the solder shall be lower or equal to the maximum operating temperature of the thermoelectric cooler. When plating tin on the heat sink, we shall keep the temperature of the heat sink in a proper temperature, which could melt the solder but not exceed the maximum operating temperature of the TEC . (d) Cover the solder flux on the hot end of the TEC, and then place the TEC on the pre tin area...(more)

The soldering of TECs in Thermo-electric Cooling System (I)

Time: 2015-05-28 15:59:19    Click: 267

When proper measures have been adopted to protect the TEC s from being overheated, we can solder the TEC with metalized surface to thermoelectric components. In order to prevent the TEC from excessive mechanical force, solder one surface (usually hot end) to a component with rigid structure. Its worth noted that when we solder the TEC to a rigid structure component, other components or small circuits shall be soldered in the cold end of the TEC, which will not connect to the external structure r...(more)

Comparing TEC with vapor compression

Time: 2015-05-27 13:44:01    Click: 186

Thermoelectric cooler (TEC) is built due to the Peltier effect, which both have the abilities of heating and cooling. When comparing with the traditional cooling method, vapor compression cooling, TEC has the following features: 1) TECs need no refrigerant, so there is no leakage or pollution. 2) Because of no mechanical rotation parts, when TEC works, there are no noise, no wear, long service life, with high reliability and convenient maintenance. 3) The cooling speed and temperature can be adj...(more)

The basic principle of TEC (II)

Time: 2015-05-26 16:21:37    Click: 297

The cooling principle of TEC is shown in figure 1. P and N type semiconductors are sandwiched between metal plates, which can form a pathway. Under the action of external electric field, the hole of P type in the point(a) needs to absorb certain energy to improve its own potential energy and then goes into P type semiconductor, so the temperature of the junction can be decreased and the cold contact point is formed. But the hole in the point(b) needs to release the excess energy to enter theshee...(more)

Basic principle of TEC (I)

Time: 2015-05-22 17:24:51    Click: 216

In the closed circuit with two different metals, if the temperature of the two contact points keeps different, electric potential difference will generate and at the same time, there will be current through the closed circuit, which is called Seebeck effect. Conversely, in the same closed circuit, when the direct current is supplied, one contact point becomes cold and the other one gets hot, which is called Peltier effect or thermoelectric effect. This phenomenon can directly lead to the inventi...(more)

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