In scenarios such as 5G communication base station heat dissipation, laser constant temperature control, and portable refrigerators, a refrigeration device that does not require a compressor, has no mechanical vibration, and is only the size of a coin is quietly changing the traditional temperature control mode - semiconductor refrigeration devices.Its core principle is based on the Peltier effect in the thermoelectric effect, which directly drives the directional transfer of heat through electrical energy, achieving efficient, precise, and silent cold and hot control.

　　1、 Peltier Effect: Cold and Hot Magic in Charge Transfer

When direct current passes through a thermocouple pair composed of P-type and N-type semiconductors, charge carriers (holes and electrons) migrate at the junction. At the "cold end" of the P-N junction, holes enter the N-type material from the P-type material, while electrons flow in the opposite direction, resulting in a decrease in carrier energy and absorption of surrounding heat; At the 'hot end', the energy of charge carriers increases, releasing heat into the environment. This process does not require refrigerants or mechanical components, and only achieves refrigeration through direct conversion of electrical and thermal energy.

Experimental data shows that the coefficient of performance (COP) of single-stage semiconductor refrigeration chips can reach 0.5-0.7, and when the temperature difference is ≤ 30 ℃, 2-5 watts of heat can be transferred per watt of input power. If a multi-stage series or cascade structure is used, the temperature difference can exceed 100 ℃, meeting the demand for deep low temperature.

　　2、 Simplified Structure: Modular Design from Chip to System

The core of a semiconductor refrigeration device is the thermoelectric module, which is composed of dozens of pairs of P-N type semiconductors connected in series through conductive ceramic plates. Ceramic plates not only serve as electrodes to connect circuits, but also dissipate heat from the cold and hot ends through high thermal conductivity ceramics such as alumina. Aluminum heat dissipation fins and micro fans are usually installed on both sides of the module to enhance the heat dissipation efficiency at the hot end.

Taking a portable constant temperature box as an example, it uses a semiconductor refrigeration chip powered by 24V DC, with the cold end attached to the inner wall of the box and the hot end connected to heat dissipation fins. By using PID temperature control algorithm to adjust the current, the 5L space can be reduced from 25 ℃ to 5 ℃ within 10 minutes, with a temperature fluctuation of ± 0.5 ℃. Compared to compressor refrigeration, the volume is reduced by 60% and the noise is reduced to below 30 decibels.

　　3、 Application boundary expansion: from precision instruments to people's livelihood fields

In the field of precision manufacturing, semiconductor refrigeration provides a millisecond level response constant temperature environment for lasers and infrared detectors, ensuring equipment stability; In the medical industry, portable refrigerated containers utilize their non liquid refrigerant properties to safely transport vaccines and biological samples; In the field of consumer electronics, mobile phone heat dissipation back clips and computer CPU temperature control modules quickly export heat through semiconductor cooling to prevent overheating and frequency reduction.

With the advancement of materials science, new thermoelectric materials such as bismuth telluride based alloys and skutterudite compounds have increased refrigeration efficiency by 30%, while the development of flexible thermoelectric films has made wearable devices and smart fabric temperature control possible. Semiconductor refrigeration devices are redefining the boundaries of temperature control technology with their advantages of "quietness, precision, and miniaturization".