Invisible "radiator" of electronic equipment: magical application of heat conduction pad
The common problems, such as the sudden jamming of the mobile phone when playing games, the fan spinning wildly when the laptop is running software, and the disconnection of the router after working for a long time, mostly stem from the "fever crisis" of electronic equipment. Electronic components will continue to generate heat when working. If the heat cannot be discharged in time, it will not only reduce the performance of the equipment, but also shorten the service life and even cause safety hazards. In many heat dissipation schemes, the seemingly inconspicuous thermal pad is the key role to solve this problem.
What is a thermal pad?
Thermal pad is a kind of polymer composite material with silica gel as the core substrate and mixed with high thermal conductivity fillers such as metal oxides (such as alumina) and carbon materials (such as graphene). It is soft in texture, can be cut at will, and can be attached to the surface according to the shape of electronic components. It is not as hard and rigid as a metal heat sink, and it does not need complicated application of liquid thermal paste.
It seems that the electronic components are closely attached to the radiator, but there is actually a tiny gap, and the air in the gap has extremely poor thermal conductivity (only one thousandth of that of metal), which will form a "thermal barrier". The core function of the thermal pad is to fill these gaps, remove air, minimize the thermal resistance, and let the heat generated by the components be quickly transferred to the radiator, and then discharged through fans, cooling holes and other means to achieve efficient heat transfer.
Specific application of thermal pad in different electronic components;
(1) Computer field CPU and graphics card are the "big fever families" of computers, especially the high-performance graphics cards of game books or desktops, and the working temperature can soar above 80℃. Between these components and the heat dissipation module, the heat conduction pad can closely adhere to the uneven surface, and cooperate with the heat pipe to quickly conduct away the heat, so as to avoid CPU frequency degradation due to overheating and graphics card jamming due to high temperature, and ensure the continuous high-performance operation of the equipment.
(2) Communication equipment Communication equipment such as base stations and routers need to work 24 hours a day, and internal signal processing chips and power modules will continue to generate heat. If the temperature is too high, the signal may be interrupted. The heat-conducting pad is installed between these heating elements and the equipment shell (or built-in heat sink), which can stably export heat without additional power supply and ensure the smooth and stable communication signal.
(3) Automotive electronics Battery management system (BMS) and on-board computer of new energy vehicles are extremely sensitive to temperature. Too high or too low temperature will affect battery life and driving safety. By virtue of its resistance to high and low temperature (-40℃~200℃), the thermal pad can fit the battery pack and the heat dissipation plate, adjust the temperature in real time, and be insulated and nonconductive, thus avoiding the risk of short circuit.
(4) Consumer electronic products Smart phones and tablets are too small to accommodate large heat sinks. Sticking thin thermal pads on the surfaces of processors, power amplifiers and other components can quickly transfer heat to the fuselage shell, reduce the phenomenon of "local burning", make users more comfortable to hold, and avoid the aging of components due to high temperature.
(5) LED lighting Although the LED lamp saves energy, the light source chip will still generate heat when it works. If the heat accumulates, it will lead to the dimming of the light and shorten the service life. The heat conducting pad is sandwiched between the LED light source and the heat dissipation substrate, which can efficiently conduct heat, keep the LED lamp stable in brightness, and prolong its service life by more than 30%.
Compared with other heat dissipation materials, the thermal pad has outstanding advantages: first, it has strong insulation to avoid short circuit of components; Second, it has good flexibility and adapts to complex surfaces; Third, the installation is convenient, and it can be pasted after cutting without professional tools; Fourth, it is stable for a long time, not prone to aging and deformation, and can continue to play a heat dissipation role without frequent replacement.
When selecting, focus on three core indicators: First, thermal conductivity (unit: w/(MK)), the higher the value, the better the thermal conductivity, just choose 1-3 w/(MK) for ordinary equipment and 5 w/(MK) or above for high-performance equipment; Second, the thickness, according to the gap between the component and the radiator, is generally 0.5-5mm, too thick will increase the thermal resistance; The third is the working temperature range, which ensures the matching with the working environment of the equipment. For example, the automobile electronics needs to choose high and low temperature resistant models.
From daily mobile phones and computers to industrial communication base stations and automobile electronics, the thermal pad acts as an "invisible guardian" to ensure the stable operation of electronic equipment. With the development of technologies such as 5G and new energy vehicles, the requirements for heat dissipation will be higher, and the future thermal pads will be upgraded in the direction of higher thermal conductivity, lighter and more environmentally friendly, which will continue to "cool down" the development of the electronics industry.
