KR100913338B1 - Heat sink, circuit board and electronic device - Google Patents

Abstract

The present invention provides a heat sink for dissipating n heat generating circuit elements mounted on a circuit board, comprising: a case having a heat receiving surface receiving heat from the n heat generating circuit elements, and a case for pressing and fixing the case to the circuit board. Provided is a heat sink comprising n + 2 fixing portions on which n + 2 fixing members are mounted.

Notebook PC, Heat Sink, Hinges, Motherboard, Pointing Device

Description

Heat Sinks, Circuit Boards, Electronics {HEAT SINK, CIRCUIT BOARD AND ELECTRONIC DEVICE}

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to heat sinks, circuit boards, and electronic devices, and more particularly, to fixing heat sinks to circuit boards on which heat generating circuit elements (hereinafter, simply referred to as "heating elements") are mounted. will be. Here, the "electronic device" is a concept including, for example, a notebook personal computer (hereinafter referred to as "PC"), a server, a personal digital assistant (PDA), an electronic dictionary, an electronic stationery, a game machine, and the like.

In recent years, with the spread of electronic devices, the demand for supplying small-sized, high-performance electronic devices at a low price is increasing, and the reduction of the number of parts is being examined. Notebook PCs, which are typical examples of electronic devices, are equipped with heat-generating elements such as CPUs and chipsets. In order to thermally protect the heat generating element, a heat radiating device called a heat sink is thermally connected to the heat generating element. The heat sink includes a cooling fin and radiates heat of the heat generating element by natural cooling. In the case of an element having a large heat generation amount, heat dissipation of the heat generation element is also performed by forced air cooling using a cooling fan. The heat sink is mounted on the heat generating element, and is fixed through the fixing member at four corners of the heat generating element. The fixing member presses a heat sink against the heat generating element, such as a bolt passing through the coil spring, to reduce the heat transfer loss and to secure a predetermined heat dissipation efficiency.

Conventionally, although a heat sink is mounted for each heat generating element, even if the heat generating element does not reach a predetermined heat generation amount, the heat sink is not mounted. However, with the recent increase in the mounting density, the distance between the CPU and the chipset is approaching, etc., and a method of simultaneously dissipating a plurality of heat generating elements with one heat dissipation device has been proposed (for example, a patent document). 1 to 3).

Patent Document 1: Japanese Patent Application Laid-Open No. 08-255856

Patent Document 2: Japanese Unexamined Patent Publication No. 07-058470

Patent Document 3: Japanese Unexamined Patent Publication No. 08-023182

However, these publications do not disclose how to fix one heat sink to a plurality of heat generating elements. Even in one heating element, if the heat sink is pressurized and fixed at four corners, the pressing force is not uniform. In the part where the pressing force is low, the heat transfer loss is large, the heat dissipation effect is lowered, and a risk of thermal breakage occurs. On the other hand, it is also considered to increase the pressing force as a whole such that the minimum pressing force is equal to or higher than a predetermined value, but this causes an overload of the portion under the maximum pressure, which causes a risk of mechanical destruction. Advantageously, an elastic member such as silicone rubber is sometimes inserted between the heat sink and the heat generating element. In this way, the elastic member can correct the uneven pressure distribution. However, such an elastic member has low thermal conductivity and lowers the heat radiation efficiency of the heat generating element. For this reason, with the recent increase in the amount of heat generated by the heat generating element, the thickness must be thin, and it is difficult to increase the thickness as the uneven pressure distribution is corrected. In addition, when heat dissipating a plurality of heat generating elements with one heat sink, all the heat generating elements may not be sufficiently radiated, which causes thermal breakdown.

Accordingly, an object of the present invention is to provide a heat sink, a circuit board, and an electronic device that efficiently and effectively radiate one or a plurality of heat generating circuit elements.

The heat sink as one side of the present invention is a heat sink for dissipating n heat generating circuit elements mounted on a circuit board, and includes a case having a heat receiving surface receiving heat from the n heat generating circuit elements. And n + 2 fixing parts to which n + 2 fixing members for pressing and fixing the case to the circuit board are mounted. The number of heat generating circuit elements n is 2 or more, and the heat sink is n heat generating elements. A line for dissipating the circuit elements in common and connecting two fixing portions of the n + 2 fixing members pass between two adjacent heat generating circuit elements. Such a heat sink can reduce the number of parts of a fixing member from the conventional 4n, and can expect reduction of cost, improvement of mounting density, and miniaturization of an electronic device. In addition, such a heat sink can fix each heat generating circuit element three points. Since three points define the geometric plane, fixing stability is higher than four points. By pressurizing between a heat sink and a heat generating circuit element, the heat transfer loss between them can be made small and a heat dissipation efficiency can be improved. If there is a heat generating circuit element in a triangle composed of three points, the fixing force from each fixing member extends to the heat generating circuit element, and if it is at the center, the distribution of the fixing force applied to the heat generating circuit element tends to be uniform. Such a heat sink can arrange each heat generating circuit element in a triangle. Here, the "circuit board" may be a printed board (also called a "motherboard" or a "system board"), and may be a package board mounted on a printed board such as a ball grid array (BGA) package or a land grid array (LGA) package. It is also intended to include.

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In the three fixing members closest to one heat generating circuit element among the n + 2 fixing members, the distance between the fixing member furthest from the one heat generating circuit element and the one heat generating circuit element is 1 cm. It is preferable to be within. If the distance is too large, the pressure distribution for the n heat generating circuit elements is likely to be nonuniform. The heat sink may further include a cooling fin that is housed in the case and that radiates at least one of the n heat generating circuit elements. Accordingly, it is possible to select whether or not to install the cooling fins according to the amount of heat generated. The cooling fin may be configured to be removable from the case. As a result, several types of cooling fins of suitable size can be prepared and combined with the case, thereby supporting a heating element of various sizes and heating values. The heat sink may further have a cooling fan which blows in the said case and forcibly cools the said cooling fin (heat sink with fan). Thereby, n heat generating circuit elements can be cooled simultaneously by one cooling fan.

A circuit board according to another aspect of the present invention includes n heat generating circuit elements, the heat sinks described above, and n + 2 fixing members for pressing and fixing the heat sinks to the heat generating circuit elements. . This circuit board also has the same function as the heat sink described above. The pressing force applied by the n + 2 fixing members may be variable. Thereby, the nonuniformity of the pressing force when the upper surface of the heat generating circuit element is not horizontal can be prevented.

The aspect having the above-mentioned circuit board (for example, a notebook PC) also constitutes one aspect of the present invention.

Other objects and further features of the present invention will become apparent from the following description with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS The external appearance perspective view of the electronic device (note-type PC) as one side of this invention.

FIG. 2 is an external perspective view of a motherboard (circuit board) of the electronic device shown in FIG. 1. FIG.

3 is a partially enlarged perspective view of the motherboard shown in FIG. 2;

4 is an exploded perspective view of a heat sink near the motherboard illustrated in FIG. 2.

FIG. 5 is an exploded perspective view of the vicinity of a heat sink viewed from the back surface of the motherboard shown in FIG. 2. FIG.

6 is a schematic plan view for explaining a method of fixing a heat sink of this embodiment.

7 is a schematic plan view for explaining a conventional method of fixing a heat sink.

EMBODIMENT OF THE INVENTION Hereinafter, the electronic device 100 as an aspect of this invention embodied as a notebook PC is demonstrated with reference to attached drawing. 1 is an external perspective view of the notebook PC 100. Referring to FIG. 1, the electronic device 100 is exemplarily embodied as a notebook PC 100, but is not limited thereto. A PDA, a portable computer, a palm-size personal computer, a wearable computer, an electronic dictionary, and an electronic stationery may be used. , Portable electronic devices such as game machines, portable home appliances (eg, portable televisions, portable video decks, portable DVDs). In addition, the size of the notebook PC 100 covers A4 size, B5 size, other subnote size, mininote size and the like.

The notebook PC 100 includes a PC main body 110, a hinge 120, a display unit (LCD bezel frame) 130, and a motherboard (circuit board) 140 not shown in FIG. 1. Have The main body 110 and the display unit 130 constitute a case of the notebook PC 100.

The main body part 110 has a case structure of about 20-30 mm in thickness, for example, and has the upper cover 111, the middle cover which is not shown in figure, and the lower cover 112. As shown in FIG. The upper cover 111, the middle cover, and the lower cover 112 are all formed by resin molding. The main body unit 110 houses the motherboard 140 and the hard disk drive HDD, and the upper cover 111 includes a keyboard 114 for information typing and a pointing device 116.

The upper cover 111 is a palm rest and is an area for placing a palm or a wrist, which is used in front of the keyboard 114. The type of the keyboard 114 does not matter 101, 106, 109, elgonomic, etc., and the keyboard arrangement is QWERTY arrangement, DVORAK arrangement, JIS arrangement, new JIS arrangement, Japanese input consortium reference arrangement (NICOLA: NIhongo Nyuryoku COnthotium LAyout). The pointing device 116 emulates some of the mouse functions to include a touchpad, click button, and rolled scroll wheel. The touchpad also realizes a mouse function on the LCD screen 132 when the user moves the forefinger. The click button has the same function as the left and right click buttons of the mouse. Since the roll type scroll wheel having the same function as the scroll wheel of the mouse is inserted between the left and right click buttons, the operability of the pointing device 116 is improved.

The hinge portion 120 includes a hinge cover and a shaft. The hinge portion 120 connects the display unit 130 to the body portion 110 so that the display unit 130 can rotate around the body portion 110 around the shaft. The hinge cover is equipped with a power button, but this arrangement is exemplary.

The display unit 130 has a front cover 131, an LCD screen 132, and a back cover 133. The front cover 131 and the back cover 133 are screwed, and the LCD screen 132 is disposed between them. The front cover 131 has a hollow rectangular shape and is connected to the hinge cover at the center bottom as a frame formed by resin molding. The back cover 133 has a substantially rectangular shape when viewed from the front. The back cover 133 is connected to the hinge cover at the center bottom. The back cover 133 is formed by resin molding.

 As shown in FIGS. 2 to 5, the motherboard 140 includes a CPU 142, a chipset 144, a heat sink 150, a cooling fan 170, and a notebook PC. Various circuit elements used as 100 are mounted. 2 is an external perspective view of the motherboard 140. 3 is a partially enlarged perspective view of the motherboard 140. 4 is an exploded perspective view of the heat sink 150 in the vicinity of the motherboard 140. 5 is an exploded perspective view of the vicinity of the heat sink 150 as seen from the rear surface of the motherboard 140. As shown in FIG. 4, the mother board 140 is provided with four fixing holes 141.

The CPU 142 and the chipset 144 are typical heating elements, and the type does not matter. According to the recent high mounting density, the distance between them is close, and the amount of heat generated by the CPU 142 is larger than that of the chipset 144. In addition, the chip set 144 also has a high level of graphics processing function, and the amount of heat generated is increasing year by year. In the present embodiment, a CPU and a chipset are described as an example of the heat generating element, but needless to say, the present invention can be applied to cooling other heat generating elements such as package ICs and components.

As shown in FIG. 4, the CPU 142 and the chipset 144 are attached to the heat sink 150 via the silicone rubbers 143 and 145. The silicone rubbers 143 and 145 are intended to close the gap between the CPU 142 and the chip set 144 and the heat sink 150 to uniform the pressure distribution acting on the CPU 142 and the chip set 144. The thermal conductivity is low, and the heat dissipation efficiency of the CPU 142 and the chipset 144 is reduced. For this reason, with the recent increase in the amount of heat generated by the CPU 142 and the chipset 144, the thickness cannot be reduced, and it is difficult to increase the thickness as the uneven pressure distribution is corrected. In addition, as will be described later, since the heat sink 150 of the present embodiment is fixed to the motherboard 140 so that the pressure distribution applied to the CPU 142 and the chipset 114 is constant, in another embodiment, the silicon The rubbers 143 and 145 are omitted.

In this embodiment, the heat sink 150 radiates the CPU 142 and the chipset 144 in common. The heat sink 150 is a heat sink with a fan having a case 151, a cooling fin 157, a cover 158, and a cooling fan 170.

As shown in FIG. 4, the case 151 has a cross-sectional U-shape and is, for example, a frame made of a high thermal conductive material such as aluminum, copper, aluminum nitride, artificial diamond, or plastic. . The case 151 is manufactured by sheet metal processing, aluminum die casting, and other methods. The case 151 may be formed by injection molding, for example, as long as it is made of plastic. As shown in FIG. 5, the rear surface of the case 151 has a height lower than that of the fixing portion 153, and the CPU 142 and the chipset 144 are moved through the silicone rubbers 143 and 145 by the height difference. Accept. The back surface of the case 151 functions as the heat receiving surface 151a that receives heat from the CPU 144 and the chipset 144.

The case 151 has protrusions 152a and 152b, four fixing portions 153, a screw hole 154, a ventilation path 155, and mounting portions 156a and 156c.

The protrusions 152a and 152b are connection portions for attaching the cover 158 and the cooling fan 170 to the case 151 and for attaching the case 151 to the motherboard 140. As shown in FIG. 4, the protruding portions 152a and 152b are formed on both upper sides along the longitudinal direction of the case 151. The protruding portion 152b is longer than the protruding portion 152a and forms an L-shaped space for mounting the cooling fan 170. The protruding portion 152a has a pair of fixing portions 153, a screw hole 154, and a fixing portion 156a, and the protrusions 152b include a pair of fixing portions 153 and 1. Screw holes 154 and fixing portions 156c.

The four fixing parts 153 have a function of attaching the case 151 to the motherboard 140, and a coil spring (not shown) is inserted therein. The screws 160 are respectively inserted into the fixing portions 153, and the screws 160 are tightened to the fixing holes 141. The screw 160 applies a predetermined pressing force to the case 151 through such a coil spring. As a result, the heat sink 150 is pressed against the CPU 142 and the chipset 144 at a predetermined pressing force. When the screw 160 of the fixing unit 153 is removed, the heat sink 150, the CPU 142, and the chipset 144 can be easily separated. In this embodiment, since the heat sink 150 and the heat generating element are not bonded to each other by the thermosetting adhesive (soldering), the CPU 142 and the chip set 144 are easily replaced in the case of malfunction.

The arrangement of the fixing part 153 has the effect of making the pressure distribution applied by the screw 160 uniform. Hereinafter, with reference to FIGS. 6 and 7, the pressure fixing by the fixing part 153 and the screw 160 will be described. 6 is a schematic plan view for explaining the principle of pressure fixing of the present embodiment, and FIG. 7 is a schematic plan view for explaining the conventional pressure fixing. In the present embodiment, as shown in FIG. 6, four pressing fixing points P ₁ to P ₄ are used to commonly press-fix the two heat generating elements E ₁ and E ₂ . On the other hand, conventionally, as shown in FIG. 7, each of the heat generating elements E ₁ and E ₂ was independently fixed and fixed at four corners Q ₁₁ to Q ₂₄ .

In the configuration shown in Figure 7, it becomes the pressure distribution applied to the heat generating elements (E _1, E ₂₎ uneven work, there is a possibility not to obtain sufficient heat radiation effect. As a result of examining this cause, the present inventors found that the pressure fixation is not stabilized because there are fears that a plurality of surfaces are defined at three points by defining three points in geometry. Therefore, in the present embodiment, the n heat generating elements are provided with (n + 2) fixing portions for pressing and fixing the heat sink. Such a heat sink can reduce the number of parts of the screw 160 from (n + 2) pieces from the conventional 4n, and can expect reduction of cost, improvement of mounting density, and miniaturization of an electronic device. In addition, these heat sinks, each heat-generating element (E _1, E ₂₎ can be pressed in three fixed points. Since three points define the geometric plane, fixing stability is higher than four points.

When the number of heat generating elements n is 1, it is preferable that the heat generating elements are disposed at the center of the triangle having n + 2 = 3 fixed members as the vertex. If there is a heat generating element in the triangle, the fixing force from each fixing member equally applies to the heat generating element. Advantages, it is not preferable because the nearest three dot easy to dominate the pressure fixing of the heating device, FIG. 7, the heating element (E ₁₎ substantially four fixing member (Q ₁₁ to Q ₁₄₎ are equidistant with respect to the present in the heating device . Moreover, if it exists in the center of a triangle, the distribution of the fixing force applied to a heat generating element tends to be uniform. Thus, in making triangular holding member (Q ₁₁ to Q _13), as well as to remove the Q ₁₄ one of the 7 heat-generating element (E _1), only the fixing member (Q ₁₁ to Q ₁₄₎ with respect to the shown in It is preferable that the heat generating element E ₁ be arranged at the center. The triangle may be any triangle, but as described later, it is preferable that all three vertices of the triangle and the heat generating element are close to each other. In addition, an isosceles triangle or equilateral triangle is preferable in order to make the pressure distribution applied from each vertex uniform on the heating element. In addition, it is preferable that "arranged in the center" coincides completely with the center of a triangle and the center of a heat generating element, but it is enough if a heat generating element contains the center of a triangle, even if it does not match completely.

In FIG. 6, instead of arranging three fixing members with respect to each of the heating elements shown in FIG. 7 and independently pressing and fixing them (for example, the fixing members Q ₁₁ , Q ₁₃ , and Q ₁₄ with respect to the heating element E ₁ ). ) the arrangement and the fixing member against the heat-generating element (E _2), the fixing member (Q _21, Q _22, instead of placing a Q _24)), 2 of the heat generating elements (E _1, E ₂₎ with respect to (P _2, P ₃ ) is used in common. As a result, the number of fixing members decreases from 3n to n + 2, so that the number of parts can be further reduced.

On the other hand, if the number of heat generating elements n is 2 or more, the heat sink radiates n heat generating elements in common, and the line connecting two fixing members of the (n + 2) fixing members is the center of two adjacent heat generating elements. It is desirable to pass through. In FIG. 6, the line connecting _two fixing members P ₂ and P ₃ passes between the heat generating elements E ₁ and E ₂ . Thereby, each heat generating element can be arrange | positioned in a triangle. In FIG. 6, the heat generating element E ₁ may be disposed in the triangles P ₁ to P ₃ , and the heat generating element E ₂ may be disposed in the triangles P ₂ to P ₄ to obtain the effects of the triangle described above. Can be.

In the three fixing members closest to one heating element among the (n + 2) fixing members, the distance between the fixing member furthest to the one heating element and the one heating element is preferably within 1 cm. Do. In Figure 6, the heating element (E ₁₎ the fixing member of near three points (P ₁ to P ₃₎ at the most distant the holding member to the heating element (E ₁₎ (for example, the holding member (P ₁₎₎ in It is preferable that the distance between the heat generating element E ₁ and ₁ cm or less. If the distance is too large, the pressure distribution for the n heat generating elements tends to be uneven. In other words, it is preferable that the three fixing members closest to the heat generating element are close to each other.

2 to 5, the pressure exerted by each screw 160 can be adjusted by adjusting the tightening force of the screw 160. Accordingly, even when the heights of the CPU 142 and the chipset 144 are different, the pressure distribution applied to the CPU 142 and the chipset 144 can be adjusted to be uniform.

The pair of screw holes 154 are holes to which the screws 161 are coupled. The ventilation path 155 forms a flow path of cooling gas (air) from the inlet port 155a to the exhaust port 155b. The exhaust port 155b protrudes downward and is wider than the inlet port 155a. The air discharged from the exhaust port 155b is sprayed on the heat dissipation sheet metal (not shown), or is configured to be discharged to the outside from the exhaust port of the main body 110 side. When in contact with the heat-dissipating sheet metal, the temperature of the fan-attached heat sink is usually maintained substantially constant (eg, at room temperature).

The fixing part 156a is provided in the front-end | tip of the protrusion part 152a, and the screw hole 156b is formed. The fixing part 156c is provided in the front-end | tip of the protrusion part 152b, and the screw hole 156d is formed. The screw 162 is inserted into the screw holes 156b and 156d.

The cooling (or heat dissipation) fin 157 is constituted by a plurality of aligned plate-shaped high heat conductive members (pin assemblies), and cools the CPU 142 and the chipset 144 by natural air cooling. The cooling fin 157 is provided at a portion corresponding to the CPU 142 as the rear surface of the heat receiving surface, and is stored in the case 151. Since the cooling fin 157 has a convex shape to increase the surface area, the heat radiation effect is increased. Originally, the shape of the cooling fins 157 is not limited to a plate shape, and arbitrary arrangement shapes, such as a fin shape and a curved shape, can be employ | adopted. In addition, the cooling fins 157 do not need to be aligned horizontally at regular intervals, and may be arranged radially or inclined. The number of cooling fins 157 can also be set arbitrarily. Cooling fin 157 is preferably formed of a high thermal conductivity material such as aluminum, copper, aluminum nitride, artificial diamond, plastic. The cooling fin 157 is formed by die molding, press fitting, row attachment, welding, injection molding, or the like.

In this embodiment, the cooling fins 157 are not provided on the chipset 144. The cost and weight are reduced by providing the cooling fins 157 only when necessary for heat dissipation. The cooling fin 157 may be divided from the case 151. Accordingly, the cooling fin 157 having a required size may be mounted on the case 151 according to the amount of heat generated by the heat generating element.

The cover 158 defines an upper portion of the ventilation path 155 and has a pair of mounting holes 159. The screw 161 is inserted into the mounting hole 159, and the screw 161 is inserted into the screw hole 154. As a result, the cover 158 is fixed to the case 151.

The cooling fan 170 rotates to generate an air flow to forcibly cool the cooling fins 157. The cooling fan 170 has mounting portions 171a and 171c, a power portion 172, and a propeller portion 174 fixed to the power portion 172.

The mounting portion 171a is mounted to the fixed portion 156a provided on the protrusion 152a, and the mounting portion 171c is mounted to the fixed portion 156c provided on the protrusion 152b. A mounting hole 171b is provided in the mounting portion 171a to communicate with the screw hole 156b. A mounting hole 171d is provided in the mounting portion 171c to communicate with the screw hole 156d. As a result, the cooling fan 170 is fixed to the case 151.

The power unit 172 typically has a rotating shaft, a bearing provided around the rotating shaft, a bearing house, and a magnet constituting the motor, but the power unit 172 can use any structure well known in the art. The detailed description is omitted here. However, in order to prevent heat transfer to the bearing house, it is preferable that a heat insulating part is formed on the inner circumferential wall of the bearing house. The heat insulating portion is formed by, for example, a low heat conductive material such as fluorine resin or silicone resin as a thin film.

Propeller portion 174 has a desired number of rotary vanes formed at a desired angle. The rotary vanes are arranged isometric or isometric and have the desired dimensions. The cooling fan 170 may or may not be divided between the power unit 172 and the propeller unit 174. In addition, the wiring connected to the cooling fan 170 is abbreviate | omitted.

The cooling fan 170 has an inlet port 175 and an exhaust port 176. Intake ports 175 are provided on the upper and lower surfaces parallel to the motherboard 140 to intake air from both sides. The exhaust port 176 is formed on a surface perpendicular to the motherboard 140. In this way, the cooling fan 170 has an intake direction and an exhaust direction perpendicular to each other. The cooling fan 170 is disposed on substantially the same plane as the cooling fin 157 to contribute to the thinning of the notebook PC 100.

In operation, a user of the note-type PC 100 operates the keyboard 114 or the pointing device 116. At this time, the heat generated from the CPU 142 is transferred to the cooling fins 157 through the heat receiving portion 151a of the heat coupled case 151. As a result, the heat is naturally cooled from the surfaces of the cooling fins 157 and the case 151. Heat from the chipset 142 dissipates from the surface of the case 151. In addition, the blowing from the cooling fan 170 forcibly cools the cooling fin 157. When the blowing air passes through the blowing path 155, the surface of the case 151 on the chipset 142 is also forcedly cooled. As a result, the heat dissipation efficiency further increases. In addition, the cooling fan 170 may operate always, and may energize when it detects that the heat_generation | fever amount from CPU 142 is more than fixed by the temperature sensor which is not shown in figure.

According to this embodiment, since the number of the fixing members 153 is reduced from (n + 2) to 4n in the related art, it contributes to the improvement of the mounting density of the mother board 140 added. In addition, since the pressure distribution applied by the heat sink 150 is uniformly distributed in the CPU 142 and the chip set 144, a predetermined heat dissipation efficiency can be maintained. In addition, although the chip set 144 has not been radiated in the related art, since this embodiment is not as much as the CPU 142 (that is, although the cooling fins 157 are not provided), the heat dissipation to some extent is performed. Thermal breakage and malfunction of 144 can be easily prevented. As described above, the heat sink of the present invention does not necessarily require cooling fins, and can provide a plurality of levels of heat radiation.

As mentioned above, although the preferable Example of this invention was described, this invention is not limited to these Examples, A various deformation | transformation and a change are possible. For example, in the present embodiment, although the number of heat generating elements is n = 2, even when n is 3 or more, the method of pressurizing and fixing the heat sink of the present embodiment can be applied.

According to the present invention, it is possible to provide a heat sink, a circuit board, and an electronic device that efficiently and effectively radiate one or a plurality of heat generating circuit elements.

Claims (10)

A heat sink for dissipating n heat generating circuit elements mounted on a circuit board, A case having a heat receiving surface receiving heat from the n heat generating circuit elements, It has n + 2 fixing parts to which n + 2 fixing members for pressing and fixing the case to the circuit board, The number of heat generating circuit elements n is 2 or more, and the heat sink commonly radiates the n heat generating circuit elements, And a line connecting two fixing portions of the n + 2 fixing members passes between two adjacent heat generating circuit elements. The method of claim 1, In the three fixing members closest to one heat generating circuit element among the n + 2 fixing members, the distance between the fixing member farthest from the one heat generating circuit element and the one heat generating circuit element is 1; Heat sink, characterized in that less than cm. The method of claim 1, And a cooling fin housed in the case, the cooling fins dissipating at least one of the n heat generating circuit elements. The method of claim 3, wherein And the cooling fins are configured to be removable from the case. The method according to claim 3 or 4, And a cooling fan blown in the case to forcibly cool the cooling fins. n heat generating circuit elements, The heat sink as described in any one of Claims 1-4, And n + 2 fixing members for pressing and fixing the heat sink to the heat generating circuit element. The method of claim 6, The pressing force applied by the n + 2 fixing members is variable. It has a circuit board of Claim 6, The electronic device characterized by the above-mentioned. delete delete

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