As thermoelectric cooler (TEC) is built on the basis of solid state, TEC has very high reliability. In most conditions of practical applications, TEC can provide a relatively long service lifetime. Currently, in many specific cases, the continuous work time of TEC has been over 20 years and is longer than other relative devices. However, it is still difficult to obtain specific reliability of TEC because failure and application environment are closely related. In some steady cooling conditions, a DC power supply put on the TEC is very stable and not basically interrupted, and at the same time, the reliability of TEC can be very high. The mean time before failures (MTBFs) is generally over 2000000 hours, which is usually regarded as an industrial standard. When in the application conditions of the hot and cold cycling work, MTBFs can be greatly shortened, especially when the temperature of TEC increases to a high one in the process of cycling.(more)

In working process, many thermoelectric coolers (TECs) refer to temperature increasing and declining periodically. Sometimes, this cycle can occur in the very wide temperature range. Although there is no clear boundary between cycle and non-cycle working conditions, in general case, if there are working conditions that can keep temperature regularly increasing and declining continuously, which is called thermo-cold cycling. These working conditions of the cycle generally trend to be controlled by automation or machine.(more)

According to different temperature coefficients, thermistor can be divided into two types: positive temperature coefficient thermistor (PTC thermistor) and negative temperature coefficient thermistor (NTC thermistor). Thermistor has been widely used for temperature control, temperature detection and temperature compensation of household electric appliances.(more)

Thermoelectric cooler (TEC) is an ancient technology. As early as in the 1950’s, TEC has once set off a boom. When it is connected to a power supply, it can become cold, which is very popular among home appliance manufacturers. However, because of the poor performance of components, it failed to be applied in actual life. The key, which determines the rise of decline of materials and process of TEC, is to improve figure of merit and the cooling effect of the hot and cold end.(more)

With the rapid development of science and technology, technical difficulties about material system and manufacturing technology have been solved. At home, there has been ceramic technology to produce the TEC cooling materials and the standard of the materials can be in the international advanced level. What’s more, the merit of figure of high efficient TEC with China's independent intellectual property rights has improved a lot and can be over 13×10-3K. Now when in the temperature difference of 50℃，the cooling coefficient of high efficient TEC is more than 3 and its efficiency can also be over that of compressor refrigeration.(more)

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 invention of coolers, but it is not TEC. Until in the 1950s, TEC began to be used in practical applications with the development of semiconductor technology.(more)

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 thesheet metal, and then the junction temperature will rise to form a hot contact.(more)

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:(more)

When proper measures have been adopted to protect the TECs 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. It's 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 rigidly. During soldering, in order to prevent the TEC from excessive heat, we need to control the temperature precisely. In the meantime, the temperature during the process will not exceed the operating temperature of TECs. Since the coefficients of thermal expansions of ceramic plates, heat sink and the object are different, it's not recommended to use soldering method in over 15×15 mm2 TECs.(more)

(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 .(more)