KR100446958B1 - Apparatus for radiating heat of portable computer - Google Patents

Abstract

According to the present invention, the display unit includes a heat circulation medium between the screen display unit and the rear case to emit electrical heat generated inside the main body of the portable computer and transferred to the display unit. A heat dissipation device of a portable computer comprising a heat sink for absorbing heat and a heat relay means for forming a heat transfer path between the heat sink and the heat circulating medium. Further comprising, the heat transfer fin relates to a heat dissipation device of a portable computer, characterized in that consisting of a shape memory alloy.

According to the present invention, when the temperature of the heat transfer fin made of the shape memory alloy rises, it is projected into the cooling fluid to act as a direct heat conduction passage and convective heat transfer surface, thereby increasing the heat transfer area through the heat transfer fin and protruding the surrounding fluid to increase the heat transfer coefficient. Therefore, there is an effect to promote a significant increase in the heat transfer amount.

Description

Heat dissipation device for portable computers {APPARATUS FOR RADIATING HEAT OF PORTABLE COMPUTER}

The present invention relates to a heat dissipation device of a portable computer, and more particularly, to a heat dissipation device of a portable computer that transmits electric heat generated inside the main body of the portable computer to a display unit and discharges it to the outside.

In general, one of the most concerned problems when designing an electronic circuit is that the electrical heat generated during the driving of the circuit affects the circuit value, thereby lowering the driving capability of the circuit.

In particular, in the case of a portable computer such as a laptop computer, a notebook computer, or a palmtop computer, the electric heating problem is an important part because all the components are highly integrated and miniaturized.

In the conventional portable computer, in order to solve the electric heating problem of the component, a method of forcibly blowing air to the main body or attaching a metal foil to the heat generating portion to increase the heat dissipation area is used. In this case, since the heat conduction ability of only the metal beam is usually not enough, the heat pipe of 3 mm-5 mm in diameter and 100 mm-200 mm in length is used for the metal beam.

However, this alone makes it difficult to cope with the high heat generation of new CPUs, which are becoming smaller and faster.

Therefore, in recent years, new methods using the back of the display panel, which has not been used as a heat dissipation position, have been attempted to secure a wider heat dissipation area.

These new attempts usually transfer electrical heat from the heating elements of the body to the circulating fluid and pump it to the back of the LCD panel to transfer heat, or transfer heat from the body to the back of the LCD panel using heat pipes. It takes a way to release it into the air.

1 is a side cross-sectional view showing a heat dissipation structure of a conventional portable computer.

Referring to the drawings, the portable computer includes a main body 30 and a display portion 40 hinged to the main body 30. The display unit 40 is provided with a liquid crystal display device 41, which is a flat panel display device, and a heat sink 43 having a similar size to the flat panel display device 41.

The main body 30 has a keyboard 31 serving as an input device on its upper surface, and a main circuit board 32 for processing a signal input through an input key and outputting display information to the liquid crystal display device 41. The heat pipe 35 is installed to transmit heat generated in the main body 30 to the heat dissipation plate 43 attached to the display unit 40. The heat pipe may optionally be replaced by circulating the working liquid with a pump.

The heat sink 43 installed in the display unit 40 is responsible for heat exchange with the outside, and heat generated from a heat source or a heating element inside the main body 30 relays heat transfer to the heat sink for heat exchange 43. Means are provided so as to extend from the inside of the main body 30 to the heat sink 43, and the heat connection between the heat generating elements and the heat relay means in the main body 30 is made by the heat sink member 34. As shown in FIG.

The shielding metal plates of the heat sink member 34 and the keyboard 31 attached to the central processing unit 33 are clamped with a bonding material 36 to a heat conductive pipe 35 made of a thermally conductive material, respectively, as a thermal relay. It is connected.

However, such an attempt also has a problem that heat transfer is not smoother than expected in the state where the back panel of the portable computer is flat, resulting in a rise in temperature of the main body.

The shape memory alloy refers to an alloy having a property of changing a crystal structure of a metal according to a change of temperature to remember a certain shape. In general, when a metal material is deformed by an external stress at a relatively low temperature, it initially exhibits elastic behavior, but soon plastic deformation occurs to become permanent deformation. However, in some alloy systems, even after plastic deformation occurs, heating the material above a certain temperature causes a phenomenon of returning to its original shape before deformation. Such a phenomenon is called a shape memory effect (SME), and an alloy exhibiting this effect is called a shape memory alloy (SMA).

More than 10 types of such shape memory alloys are known, but currently used industrially due to their characteristics and manufacturing problems include Ni-Ti alloys and Cu-Zn-Al alloys. In addition, the conventional techniques have been attempted to prevent the overheating by opening or closing the passage of the cooling fluid when the temperature inside the apparatus is increased by using the shape memory alloy as part of an opening and closing structure such as a valve or a damper.

However, since the conventional method using the shape memory alloy is not limited to the direct heat conduction of the shape memory alloy and is limited to the auxiliary means of the electric heat dissipation device, the method is also used in the highly integrated device integrated in the portable computer. It is not enough to relieve fever.

The present invention to solve the above problems, to provide a heat dissipation device that can effectively operate the electronic circuit mounted inside the main body by effectively discharging the electric heat generated inside the main body of the portable computer through the display unit. The purpose.

1 is a side cross-sectional view showing a heat dissipation structure of a conventional portable computer.

2a and 2b is a conceptual diagram showing the operation according to the temperature of the bidirectional shape memory alloy applied to the present invention.

Figure 3a and Figure 3b is a state diagram of a portable computer attached to the heat transfer fin of the shape memory alloy in accordance with the present invention.

Figure 4 is a side cross-sectional view of a portable computer with a heat radiation device according to the present invention.

In order to achieve the above object, the present invention in order to discharge the electrical heat generated inside the main body of the portable computer and transmitted to the display unit, the display unit between the screen display unit and the rear case of the heat pipe or working fluid circulation type And a heat sink, the heat sink being coupled to a heat generating element therein to absorb heat, and a heat relay means for forming a heat transfer path between the heat sink and the heat circulation medium. In the heat dissipation device, the display unit further comprises a heat transfer fin attached to the outside of the rear case, the heat transfer fin provides a heat dissipation device of a portable computer, characterized in that composed of a shape memory alloy.

In addition, the heat dissipation device according to the invention is characterized in that the shape memory alloy constituting the heat transfer fin is composed of a bidirectional shape memory alloy. The shape memorized at a high temperature of the shape memory alloy is shape memorized so as to protrude into the surrounding fluid, and the shape memorized at room temperature is memorized so as to be stored in close contact with the rear case.

In addition, the shape memory alloy to be applied to the present invention is characterized by using three types of alloys of copper series or two kinds of alloys of NiTi series.

Hereinafter, a heat dissipation device of a portable computer according to the present invention will be described in detail with reference to the accompanying drawings.

2a and 2b is a conceptual diagram showing the operation according to the temperature of the bidirectional shape memory alloy to be applied to the present invention, showing that the heat transfer fin (2) flatly attached or projected according to the temperature of the wall surface.

Referring to the drawings, the heat transfer fin (2) is a bidirectional shape memory alloy that bends when the temperature rises and becomes flat when the temperature goes down, and sets the shape as shown in the drawing in advance.

When the temperature of the wall surface 3 is low, it adheres to a wall surface and is accommodated like FIG. 2A. At this time, the heat transfer 휜 does not contribute to heat transfer because it is not in intimate contact with the surrounding fluid (mainly air or water).

Then, when the temperature of the wall surface 3 rises, the heat transfer fin 2 bends and penetrates deeply into the surrounding fluid 1 as shown in FIG. 2B. This results in active heat transfer due to convection of the surrounding fluid at the protrusions of heat transfer fin (2), resulting in a high temperature difference between the protrusions of the heat transfer and the wall attachment point, and thus conducts a lot of heat along heat transfer heat (2). To improve heat transfer.

According to the present invention, all or part of the heat transfer promoting fins attached to the high or low temperature wall is made of a bidirectional shape memory alloy, and when the temperature of the wall rises above the critical point, the fin protrudes to heat transfer and adheres to the wall below the critical point. It is made for easy storage.

This extends the application of shape memory alloys to the field of creating high value added. For example, if the heat generated by a notebook computer is transferred to a circulating fluid or the like, and the liquid is sent to a heat sink installed on the rear side of the monitor, only at elevated temperatures as in the present invention, in order to promote low efficiency heat emission by natural convection. It is very useful to attach the heat-transferring heat sink by itself.

Similar applications can be applied to mobile phones and mountain climbing cookware, and to apply these techniques to quickly warm up heating elements such as audio.

3A and 3B are state diagrams of a portable computer with heat transfer fins of shape memory alloy according to the invention, and FIG. 4 is a side cross-sectional view of a portable computer with heat transfer fins in accordance with the present invention.

As can be seen in Figure 3, Figure 3a is a state in which the heat transfer fin is stored flat when the temperature of the display unit is low, Figure 3b is a state in which the heat transfer fin is protruded into the surrounding fluid when the temperature of the display unit is raised. It is shown.

The present invention basically discloses a device for effectively radiating heat to the outside by effectively transmitting the electrical heat generated inside the main body of the portable computer to the display unit similar to the prior art described in FIG.

In the following description, a description of components similar to those of the conventional heat dissipation device described in FIG. 1 will be omitted, and only the characteristic elements of the present invention will be described to clarify the intention of the inventor.

3 and 4, the portable computer includes a main body 30 and a display portion 40 hinged to the main body 30.

The display unit 40 includes a heat circulation medium 43 between the screen display unit (for example, LCD screen) 41 and the rear case. The heat circulating medium 43 may be a heat pipe or a heat circulating liquid. As a method of transmitting heat of the main body to the back of the LCD panel, various methods currently available may be used in addition to the above methods.

In addition, the display unit further includes a heat transfer fin 42 attached to the outside of the rear case, wherein the heat transfer fin is composed of a shape memory alloy.

The shape memory alloy applied to the heat transfer fins may be NiTi-based as a two-alloy, or may be a copper-based three-alloy. The former has a limit of 10 W / m-K having a low thermal conductivity, and the latter has a W of 100 W / m-K, which can significantly increase the height of the thermal, which is more advantageous in terms of heat transfer. In particular, the latter has a high thermal conductivity, so it is sufficient to make a thin sheet of about 0.1 mm, so that it does not cause weight and volume problems.

The main body 30 is combined with a heat generating element therein to form a heat sink 34 for absorbing heat and heat transfer means 35 for forming a heat transfer path between the heat sink 34 and the heat circulating medium 43. )

The main body 30 usually includes a keyboard 31 as an input device, a coupling material 36 for heat transfer to a thermal relay means, a main circuit board 32, and a heat generating element 33 including a CPU. Is the same as the portable computer structure.

However, the present invention is that the heat inside the main body 30 transferred to the heat circulating medium 43 installed in the display unit 40 is widely released to the outside through the heat transfer fin 42 attached to the display unit 40. It is characteristic.

When the temperature of the display part 40 is low like FIG. 3A, the heat transfer fin 42 adheres to the rear case of the display part 40, and is accommodated. At this time, since it is not in intimate contact with the surrounding fluid (mainly air or water), the heat transfer fin 42 does not contribute to heat transfer.

The heat transfer fin 42 is a bidirectional shape memory alloy that bends when the temperature rises and becomes flat when the temperature decreases, and sets the shape as shown in FIG. 3 in advance.

However, when the temperature of the display unit 40 rises, the heat dissipation area 42 is bent as shown in FIG. 3B, and the heat dissipation area is expanded. In this case, the protrusions of the heat transfer fins 42 become active due to the convection of the surrounding fluid, thereby enhancing heat transfer due to heat conduction.

Although the present invention has been described in detail through the embodiments shown in the drawings, the present invention is not limited to the above embodiments, and various changes and modifications may be made without departing from the spirit or technical spirit of the present invention.

As described above, in the present invention, when the temperature of the heat transfer fin made of the shape memory alloy is increased, the present invention projects into the cooling fluid to act as a direct heat conduction passage and convective heat transfer surface, thereby increasing the heat transfer area through the heat transfer fin and protruding the surrounding fluid. As a result, the heat transfer coefficient is increased, thereby achieving a significant increase in the heat transfer amount.

In addition, since the shape memory alloy is not subjected to any mechanical force in the structure according to the present invention, it can be made into a very thin structure can reduce the material cost.

In addition, the heat dissipation device according to the present invention can not only heat dissipate through the back of the monitor of the notebook computer, but also shorten the warm-up time of the audio, improve the heat transfer efficiency of the cellular phone, the climbing cookware, and improve the storage performance.

Claims (5)

The display unit includes a heat circulating medium between the screen display unit and the rear case to emit electrical heat generated inside the main body of the portable computer and transferred to the display unit. A heat dissipation device for a portable computer, comprising: a heat sink to absorb; and heat relay means for forming a heat transfer path between the heat sink and the heat circulation medium. The display unit further comprises a heat transfer fin attached to the outside of the rear case, the heat transfer fin is a heat dissipation device of a portable computer, characterized in that consisting of a shape memory alloy. The method of claim 1, The shape memory alloy constituting the heat transfer fin is a heat dissipation device of a portable computer, characterized in that consisting of a bidirectional shape memory alloy. The method of claim 2, The shape memory stored in the shape memory alloy at high temperature is projected into the surrounding fluid shape, and the shape stored at room temperature is stored in shape to be stored in close contact with the rear case. The method of claim 1, The shape memory alloy is a heat dissipation device of a portable computer, characterized in that using a copper-based three kinds of alloys. The method of claim 1, The shape memory alloy is a heat dissipation device of a portable computer, characterized in that the use of NiTi series two alloys.