CN1878452A - Structure design of mobile terminal - Google Patents

Abstract

According to the structural design of the mobile terminal of the present invention, a radiator is provided in the relatively high temperature area on the circuit board, and the heat in the relatively high temperature area is dissipated through the mobile terminal shell; or a relatively high temperature area and a relatively low temperature area are provided on the circuit board. There is a radiator, which conducts heat from a relatively high temperature zone to a relatively low temperature zone; the material of the radiator is carbon (graphite). Carbon has the advantages of high thermal conductivity and low density. Only a small amount of manufacturing cost is added, so that the mobile terminal is small and light, with low cost, good temperature uniformity, and avoids local high temperature of the device and the mobile terminal shell.

Description

Description A structural design of a mobile terminal

technical field

The invention relates to the structural design of products in the field of electronic technology, in particular to a structural design of a mobile terminal.

Background technique

In modern society, mobile phones, that is, mobile terminals, have become an indispensable communication tool for people. People have more and more requirements for the functions of mobile terminals. With the development of wireless communication and chip packaging technology, more functions can be integrated into mobile terminals. As the mobile terminal has more and more functions, the power consumption of the mobile terminal also tends to increase. Especially, the power consumption of the mobile terminal used in the third generation network is much higher than that of the original mobile terminal. However, people often hope that the smaller the size of the mobile terminal, the better. In this way, the pressure of customer demand and competition forces mobile terminal manufacturers to pursue small-sized mobile terminals. In the same situation, the heat density per unit volume of mobile terminals increases. However, in the limited internal space of mobile terminals, heat dissipation technologies such as fans, radiators, and heat pipes cannot be used, which brings great challenges to the thermal design of mobile terminals.

The impact of the temperature of the mobile terminal on the user is mainly manifested in two aspects: excessive local temperature and uneven temperature as a whole. Under the existing technical conditions of heat consumption, in order to avoid user complaints caused by excessive surface temperature of mobile terminals, achieving uniform surface temperature and avoiding hot spots is a design focus, especially for mobile terminals with plastic substrates. Usually, the thermal conductivity of plastic is around 0.4W/m-K, and the uneven temperature distribution can reach more than 10°C. Some manufacturers, such as Chomerics, offer high thermal conductivity plastics. This high thermal conductivity plastic is mainly obtained by adding fibrous graphite or metal materials to the plastic. Its thermal conductivity is 0.7W/m-K, which can meet the requirements of use. However, this technology is developed to achieve electromagnetic shielding; it cannot be made in various colors like ordinary plastics, and its appearance is limited; very beautiful. Simultaneously, its cost increases more, can't be generally used under the present situation.

In addition, there is another way, that is, the mobile terminal adopts a metal casing, and this kind of mobile terminal is generally made of magnesium alloy, aluminum alloy and the like. Although its thermal conductivity is much higher than that of plastic, its cost is much higher than that of plastic, and it can only be used in high-end mobile terminals that are not cost-sensitive; in addition, because the thermal conductivity of metal is much higher than that of plastic, metal is more expensive at the same temperature. It is easy to make users feel hot or even hot. In fact, according to the UL60950-1 standard, under long-term contact, the maximum allowable surface temperature of mobile terminals with metal substrates is 55°C, while that of mobile terminals with plastic substrates is 75°C. For mobile terminals with large heat consumption, although the cooling effect brought by uniform temperature is obvious, the temperature after cooling can easily exceed 55°C, especially in some relatively temperature-sensitive areas such as the "answer" button or "OK" button. temperature may be higher. It is easy to reduce user satisfaction and cause complaints.

At present, in order to solve the problem, the following solutions are adopted:

The first solution: increase the heat dissipation volume and heat dissipation area of the mobile terminal. This solution obviously does not meet the requirements of mobile terminal users for the mobile terminal to be compact and portable. not easily accepted by the market.

The second solution: reduce the power consumption of the mobile terminal. This solution is limited by the development level of hardware and software; it cannot achieve low power consumption and good communication quality at the same time. Therefore, this scheme is difficult to use.

Therefore, how to solve the heat dissipation problem of the mobile terminal, make the third-generation mobile terminal small and light, low in cost, good in temperature uniformity, and avoid local high temperature of the device and the mobile terminal shell.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a structural design of a mobile terminal, which can help the surface temperature distribution of the mobile terminal to be more uniform and reduce the temperature of the sensitive area of the user; It should be very aesthetically pleasing. The mobile terminal is small and light, low in cost, good in heat dissipation effect, good in temperature uniformity, and avoids local high temperature of components and mobile terminal casing.

The purpose of the present invention is achieved through the following technical solutions:

The invention provides a structural design of a mobile terminal, including a circuit board on which there are heating elements. When the mobile terminal is working, the circuit board in the heating element area forms a local relatively high temperature area, and other areas are relatively low temperature areas. The relatively high-temperature area on the board is provided with a heat sink, and the heat in the relatively high-temperature area is dissipated through the mobile terminal shell. The material of the heat sink is carbon, that is, graphite.

In the present invention, radiators are provided on the relatively high-temperature zone and relatively low-temperature zone on the circuit board to conduct heat from the relatively high-temperature zone to the relatively low-temperature zone, and the material of the radiator is carbon.

The radiator is a thermally conductive carbon film, a thermally conductive carbon plate or a thermally conductive carbon block.

The thickness of the thermally conductive carbon film is 0.1mm˜1mm.

The heat sink is a whole covering all areas on the circuit board; or, the heat sink is a plurality of small blocks, and each small block covers at least one relatively high temperature area and/or at least one relatively low temperature area.

The radiator is fixed on the inner surface of the casing or on the heating element on the circuit board.

The radiating body is bonded to the inner surface of the casing or the heating element on the circuit board through thermally conductive glue.

Described mobile terminal comprises:

Global System for Mobile Communications GSM mobile phone, code division multiple access CDMA mobile phone, third generation mobile communication system 3G mobile phone or PHS.

It can be seen from the above-mentioned technical solution provided by the present invention that in the structural design of the mobile terminal of the present invention, a heat sink is provided in a relatively high-temperature area on the circuit board, and the heat in the relatively high-temperature area is dissipated through the mobile terminal shell; The relatively high-temperature zone and the relatively low-temperature zone on the circuit board are provided with radiators to conduct heat from the relatively high-temperature zone to the relatively low-temperature zone; the material of the radiator is carbon (graphite). Because mobile terminal shells are generally made of plastic products. This design combines the advantages of plastic materials and metal materials. The shell can be made of ordinary plastic in various colors, and the appearance is not limited; it is very beautiful, and at the same time, it has the advantages of low cost and low local temperature sensitivity. There is a thermally conductive carbon film inside, which has the advantage of high thermal conductivity. Only a small amount of manufacturing cost is added, so that the mobile terminal is small and light, with low cost, good temperature uniformity, and avoids local high temperature of the device and the mobile terminal shell.

Description of drawings

Fig. 1 is a structural diagram 1 of a mobile terminal according to the present invention;

FIG. 2 is a second structural diagram of the mobile terminal according to the present invention;

FIG. 3 is a third structural diagram of the mobile terminal according to the present invention.

Detailed ways

The internal cause of the uneven temperature distribution on the surface of the mobile terminal is the uneven heating of components on the circuit board PCB. The heating devices on the board PCB mainly include PA (power amplifier) devices, LCD (liquid crystal screen), radio frequency chips, CPU, charging transistors, cameras, and shielding boxes near high temperatures. The higher temperature of the circuit arc area where these heating elements are located is called a relatively high temperature area, and other areas are called a relatively low temperature area. The most important heat source is the PA device, which usually accounts for 40-60% of the total heat consumption of the mobile terminal. For some PAs of WCDMA and CDMA 2000, the efficiency is below 40%, and the PA device size is usually 6×6×1.9mm ³ to 3×3×1.8mm ³ . Therefore, during long-term high-power transmission, the temperature rise of the housing can reach 30-50°C. In addition, due to the thinness of the mobile terminal, the high temperature of the PA device is easily reflected directly on the surface of the mobile terminal that is closer to the PA device, such as the "OK" button on the sensitive surface of the user. Due to the low thermal conductivity of plastic, the heat is not easy to spread, resulting in local high temperature on the surface of the mobile terminal.

The mobile terminal described in the present invention may specifically include the following terminal equipment:

Global System for Mobile Communications GSM mobile phone, Code Division Multiple Access CDMA mobile phone, third generation mobile communication system 3G mobile phone or PHS, etc.

The method of the present invention to solve the local high temperature of the mobile terminal is to provide a radiator in the relatively high temperature area on the circuit board, and transfer the heat in the relatively high temperature area to the mobile terminal shell or the relatively low temperature area, so as to reduce the temperature of the relatively high temperature area and make the mobile terminal The purpose of uniform surface temperature distribution.

Specific embodiment of the present invention-as shown in FIG. 1 : several heating elements 3 and conventional elements 7 are arranged on the circuit board 6 of the mobile terminal. The surrounding area of the heating element 3 forms a relatively high temperature area 4 , and the surrounding area of the conventional element 7 forms a relatively low temperature area 5 . A radiator is provided at the relatively high temperature zone 4 . The heat sink used can be a heat conduction film 2 or a heat conduction block 8 . The heat conduction film 2 or the heat conduction block 8 is arranged between the relatively high temperature area 4 and the casing 1 of the mobile terminal, and dissipates the local high temperature heat in the relatively high temperature area 4 through the casing 1 of the mobile terminal. In this case, the heat dissipation area of the heat conduction film 2 or the heat conduction block 8 is much larger than that of the heating element 3, so that the heat can be dissipated from the casing 1 of the mobile terminal through a larger heat dissipation area, and the local high temperature on the surface of the casing 1 of the mobile terminal can be reduced. .

Embodiment 2 of the present invention is shown in FIG. 2 : several heating elements 3 and conventional elements 7 are arranged on the circuit board 6 of the mobile terminal. The surrounding area of the heating element 3 forms a relatively high temperature area 4 , and the surrounding area of the conventional element 7 forms a relatively low temperature area 5 . A radiator is provided at the relatively high temperature zone 4 . The heat sink used can be a heat conduction plate 9 or a heat conduction block 8 . The heat conduction plate 9 is arranged between the relatively high temperature area 4 and the casing 1 of the mobile terminal, and dissipates the local high temperature heat through the casing 1 of the mobile terminal. Reduce the local high temperature on the surface of the housing 1 of the mobile terminal. The heat conduction block 8 is located between the relatively high temperature zone 4 and the relatively low temperature zone 5, and transfers the local high temperature heat in the relatively high temperature zone 4 to the relatively low temperature zone 5, reducing the local high temperature of the internal components of the mobile terminal.

The third specific embodiment of the present invention is shown in FIG. 3 : several heating elements 3 and conventional elements 7 are arranged on the circuit board 6 of the mobile terminal. The surrounding area of the heating element 3 forms a relatively high temperature area 4 , and the surrounding area of the conventional element 7 forms a relatively low temperature area 5 . A radiator is provided at the relatively high temperature zone 4 . The heat sink used can be a thermally conductive film 2 . The heat conduction film 2 covers all areas on the circuit board 6 as a whole, and it is arranged between the relatively high temperature zone 4 and the casing 1 of the mobile terminal, which not only dissipates the local high temperature heat through the casing 1 of the mobile terminal, but also reduces the movement Local high temperature on the surface of the housing 1 of the terminal. At the same time, the heat conduction film 2 also covers the relatively high temperature zone 4 and the relatively low temperature zone 5 at the same time, transfers the local high temperature heat in the relatively high temperature zone 4 to the relatively low temperature zone 5, and reduces the local high temperature of the internal components of the mobile terminal. In this case, it is generally required that the heights of the heating elements 3 on the circuit board 46 be the same or have very little difference. When the heights of the heating elements 3 on the circuit board 6 are different or have a large difference, the methods of the first embodiment and the second embodiment are generally adopted.

In the above embodiments, the heat sink may use carbon (graphite). Since the transverse thermal conductivity of carbon can reach 400W/m-K, the longitudinal thermal conductivity is 15W/m-K. At the same time, the density is 70% of aluminum and 21% of copper. The utility model has the advantages of small weight and good heat dissipation effect. The use of thin film materials can not only reduce costs, but also save space, which is very important for mobile terminals that require a small size. Therefore, the preferred solution of the present invention is to use carbon film.

In the above embodiments, the carbon film used has a thickness of 0.1mm˜1mm. Generally, a carbon film with a thickness of 0.2 mm is commonly used.

For example, the temperature distribution before and after the 0.15mm thick carbon film is sandwiched between the keyboard surface and the casing of the mobile terminal is shown in Table 1 for comparison of the test results. After using the carbon film, the maximum temperature rise on the surface decreased by 3.07°C. It should be noted that due to the characteristics of the infrared imaging test itself, the ambient temperature comes from the results of the thermocouple test.

Table 1 Test items Test Conditions No carbon film between the keyboard and the shell Carbon film is sandwiched between the keyboard and the shell Heat consumption (W) Q=2.079 Q=2.08 Ambient temperature (℃) 22.2 21.3 Maximum temperature rise (℃) 29.74 26.67 "OK" key temperature rise (℃) 28.68 25.31 "2" key temperature rise (℃) 22.8 21.47 "0" key temperature rise (℃) 20.42 21.45

In the above embodiments, the radiator can be fixed on the inner surface of the casing 1 or on the heating element 3 on the circuit board 6 . Generally, the fixing method adopts heat-conducting adhesive to be directly bonded to the inner surface of the casing 1 or the heating element 3 on the circuit board 6 .

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (8)

1, a kind of structural design of portable terminal, comprise circuit board, heater element is arranged on circuit board, circuit board in the heater element zone during portable terminal work forms local relatively-high temperature district, other zone is exactly relative low-temperature space, it is characterized in that, the relatively-high temperature district on circuit board is provided with radiator, distribute the heat in relatively-high temperature district by mobile terminal case, the material of described radiator is a carbon.

2, the structural design of portable terminal according to claim 1 is characterized in that, the relatively-high temperature district on circuit board is provided with radiator with relative low-temperature space, and the heat in relatively-high temperature district is transmitted to relative low-temperature space, and the material of described radiator is a carbon.

3, the structural design of portable terminal according to claim 1 and 2 is characterized in that, described radiator is heat conduction carbon film, heat conduction carbon plate or heat conduction carbon piece.

4, the structural design of portable terminal according to claim 3 is characterized in that, the thickness of described heat conduction carbon film is 0.1mm～1mm.

5, the structural design of portable terminal according to claim 1 is characterized in that, described radiator is the All Ranges on the whole covering board; Perhaps, described fin is several fritters, and each fritter covers at least one relatively-high temperature district and/or at least one relative low-temperature space.

6, the structural design of portable terminal according to claim 1 or 5 is characterized in that, described radiator is fixed on the heater element on shell inner surface or the circuit board.

7, the structural design of portable terminal according to claim 6 is characterized in that, described radiator is adhered on the heater element on shell inner surface or the circuit board by heat-conducting glue.

According to the structural design of claim 1,2 or 5 described portable terminals, it is characterized in that 8, described portable terminal comprises:

Global system for mobile communications GSM mobile handset, code division multiple access CDMA mobile phone, 3-G (Generation Three mobile communication system) 3G mobile or Personal Handyphone System.

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