Heat-Receiving apparatus and electronic equipment

The present invention relates to a heat receiving device having a heat receiving surface thermally connected to a heating element such as a CPU, and an electronic device including the heat receiving device.

CPUs used in portable computers generate more heat during operation as the processing speed increases and the number of functions increases. If the temperature of the CPU becomes too high, problems such as loss of efficient operation or unnecessary operation will occur.

As a cooling measure for a heating element such as a CPU, a heat receiving device such as a cold plate provided with a heat receiving unit that is thermally connected to the heating element is known. The cold plate receives the heat of the heating element. The heat receiving portion has a heat receiving surface that is thermally connected to the heating element. The heat receiving surface is adhered to the heating element via a heat transfer member such as a heat conductive silver paste or an adhesive interposed between the heating element. (See, for example, Patent Document 1.).<patcit num="1"><text>Japanese Unexamined Patent Publication No. 10-303582</text></patcit>

<p> By the way, in general, when a heat receiving device such as a cold plate is attached to a heating element, the heat receiving device is attached to the heating element after the heat transfer member is provided on the heating element mounted on a printed circuit board or the like. However, depending on the heating element, when mounted on a printed circuit board, It may be difficult to provide a heat transfer member on the surface due to electronic components located in the surroundings.</p><p> The present invention has been made based on such circumstances, and an object of the present invention is to obtain a heat receiving device capable of efficiently interposing a heat conductive member between a heat receiving surface and a heating element.</p><p> Another object of the present invention is to obtain an electronic device provided with the above heat receiving device.</p>

<p> In order to achieve the above object, it relates to one embodiment of the present invention.<u style="single">The electronic device includes a housing having a heating element, a heat radiating section, a circulation path that is thermally connected to the radiating section and circulates a refrigerant, and a heat receiving section and a pump chamber that are thermally connected to the heating element. It is provided with a housing having the above, an impeller provided in the pump chamber, a motor for rotating the impeller, and a pump for sending the refrigerant to the circulation path. The heat receiving unit includes a heat receiving surface that is thermally connected to the heating element. The pump is arranged in the pump chamber so that a position away from the rotation axis of the impeller faces the heating element. The heat receiving surface includes a guide indicating an facing area which is a region facing the heating element on the heat receiving surface.</u>。 </p>

<p> According to the present invention, the heat conductive member can be efficiently interposed between the heat receiving surface and the heating element.</p>

Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 7. FIG. 1 discloses a portable computer 10 as an electronic device. The portable computer 10 includes a computer main body 20 and a display unit 30. The computer body 20 includes a flat box-shaped first housing 21.

The upper wall 21b of the first housing 21 supports the keyboard 22. As shown in FIG. 2, a plurality of exhaust ports 25 are formed on the rear wall 21e of the first housing 21. As shown in FIG. 1, the display unit 30 includes a second housing 31 and a liquid crystal display panel 32. The liquid crystal display panel 32 is housed in the second housing 31. The liquid crystal display panel 32 has a screen 33 for displaying an image. The screen 33 is exposed to the outside of the second housing 31 through an opening 34 formed in the front surface of the second housing 31.

The second housing 31 is supported at the rear end of the first housing 21 via a hinge (not shown). Therefore, the display unit 30 is located between the closed position lying on the computer body 20 so as to cover the keyboard 22 from above and the open position standing upright with respect to the computer body 20 so as to expose the keyboard 22 and the screen 33. It can be rotated with.

As shown in FIG. 2, the first housing 21 houses the printed circuit board 23. The CPU 24 is mounted on the upper surface of the printed circuit board 23. The CPU 24 is an example of a heating element referred to in the present invention. The CPU 24 includes a base board 24a and an IC chip 24b.

The IC chip 24b is located on the upper surface of the base substrate 24a. The upper surface 26 of the IC chip 24b is a quadrangle and has four corners 26a to 26d. The upper surface 26 of the IC chip 24b is an example of the thermal connection surface referred to in the present invention. The IC chip 24b generates a very large amount of heat during operation as the processing speed increases and the number of functions increases, and cooling is required to maintain stable operation.

The computer main body 20 houses a liquid-cooled cooling device 40 that cools the CPU 24 using a liquid refrigerant such as antifreeze. The liquid refrigerant is an example of the refrigerant referred to in the present invention. The cooling device 40 includes a heat radiating unit 50, an electric fan 60, a pump 70, and a circulation path 120.

The heat radiating portion 50 is attached to the bottom wall 21a of the first housing 21. The heat radiating unit 50 includes a heat radiating unit main body 51 and heat radiating fins 52. The heat radiating portion main body 51 is composed of a pipe that extends along the width direction of the first housing 21 and is folded back in the vertical direction to have an upper passage portion and a lower passage portion. The heat radiating unit main body 51 has a refrigerant inlet 53 and a refrigerant outlet (not shown) on one end side in the longitudinal direction. A liquid refrigerant circulates inside the heat radiating unit main body 51.

The heat radiating fin 52 is made of a metal material having excellent thermal conductivity, such as an aluminum alloy or copper. A plurality of heat radiating fins 52 are provided in parallel in the vertical direction between the upper passage portion and the lower passage portion of the heat radiating portion main body 51. The heat radiating fin 52 and the heat radiating unit main body 51 are thermally connected.

The electric fan 60 is for blowing cooling air to the heat radiating unit 50, and is located immediately before the heat radiating unit 50. The electric fan 60 includes a fan casing 61 and a centrifugal impeller 62 housed in the fan casing 61. The fan casing 61 has a discharge port 61a for discharging cooling air. The discharge port 61a is connected to the heat radiating portion 50 via the air guide duct 63.

The impeller 62 is driven by a motor (not shown), for example, when the portable computer 10 is turned on or when the temperature of the CPU 24 reaches a predetermined value. As a result, the impeller 62 rotates, and cooling air is supplied from the discharge port 61a of the fan casing 61 toward the heat radiating portion 50.

As shown in FIG. 3, the pump 70 includes a pump housing 71, an impeller 72, a motor 73, and a control board 75. The pump 70 is an example of the heat receiving device referred to in the present invention, but is not limited thereto. For example, a heat sink may be adopted as the heat receiving device. The heat sink has a function of cooling a heating element, for example, the CPU 24. The heat sink is not limited to using a liquid refrigerant when cooling the heating element.

The pump housing 71 is an example of the housing referred to in the present invention. As shown in FIG. 4, the pump housing 71 includes a housing body 76, a top cover 77, and a heat receiving plate 78.

The housing body 76 is formed in a flat rectangular shape. The housing body 76 is made of synthetic resin. As shown in FIG. 5, the housing body 76 has a housing portion 79 that penetrates from the upper end surface to the lower end surface.

As shown in FIG. 6, the accommodating portion 79 is defined by the inner surfaces of the four side walls 76a to 76d of the housing body 76 and the inner surfaces of the four corners 76e to 76h having a substantially right-angled triangular shape, and has a flat octagonal shape. It is formed.

Grooves 79b are formed around the upper opening 79a of the accommodating portion 79 on the upper end surfaces of the housing body 76, that is, the side walls 76a to 76d and the upper end surfaces of the corner portions 76e to 76h. An O-ring 74 is provided in the groove portion 79b.

As shown in FIGS. 5 and 6, first through holes 80 are formed in the corners 76e to 76h. The first through hole 80 penetrates the housing body 76 in the vertical direction. As shown in FIG. 6, on the upper end surface of the housing body 76, screw receiving portions 80b are provided at both ends of the first through holes 80. A groove 79b is formed around the accommodating portion 79 on the lower end surface of the housing body 76. An O-ring 74 is provided in the groove portion 79b.

The heat receiving plate 78 has a size that covers the entire lower end surface of the housing body 76, and is attached to the lower end surface of the housing body 76. The heat receiving plate 78 has a function as a bottom wall of the accommodating portion 79. Since the O-ring 74 is provided on the lower end surface of the housing body 76, the heat receiving plate 78 liquidally closes the lower opening 79c of the accommodating portion 79. The heat receiving plate 78 is made of a metal material having good thermal conductivity such as copper. Copper is an example of the material of the heat receiving plate 78. The heat receiving plate 78 is an example of the heat receiving portion referred to in the present invention.

The heat receiving plate 78 has a second through hole 82 formed at a position corresponding to each first through hole 80. The second through hole 82 is formed smaller than the first through hole 80. In the heat receiving plate 78, the surface opposite to the housing body 76 is the heat receiving surface 83 that receives heat from the CPU 24. The heat receiving surface 83 is formed flat.

In the heat receiving plate 78, a partition member 85 that separates the flat circular pump chamber 84 from the accommodating portion 79 is provided on the surface facing the inside of the accommodating portion 79. As shown in FIG. 6, the partition member 85 is closer to the corner portion 76 g side. Therefore, the pump chamber 84 is closer to the corner 76 g side of the accommodating portion 79. The position of the partition member 85 is not limited.

The inside of the accommodating portion 79 is divided into a pump chamber 84 and a reserve tank 86 by a partition member 85. The pump chamber 84 is formed inside the partition member 85. The reserve tank 86 is formed on the outside of the partition member 85.

As shown in FIG. 6, the partition member 85 is provided with a communication port 87 that communicates the inside of the reserve tank 86 with the inside of the pump chamber 84. The housing body 76 is provided with a suction pipe 90 and a discharge pipe 91. The upstream end of the suction pipe 90 projects outward from the side wall 76b of the housing body 76. The downstream end of the suction pipe 90 opens inside the reserve tank 86 and faces the communication port 87.

A gap 92 is formed between the downstream end of the suction pipe 90 and the communication port 87. The gap 92 has a gas-liquid separation function for separating air bubbles in the liquid refrigerant. The gap 92 is always located below the liquid level of the liquid refrigerant stored in the reserve tank 86 regardless of the orientation of the pump 70.

The downstream end of the discharge pipe 91 projects outward from the side wall 76b of the housing body 76. The upstream end of the discharge pipe 91 penetrates the partition member 85 and opens inside the pump chamber 84.

As shown in FIG. 4, the top cover 77 is provided above the housing body 76 so as to cover the upper opening 79a of the accommodating portion 79 of the housing body 76. The top cover 77 is made of synthetic resin. At the corner of the top cover 77, a hole 77a is formed at a position corresponding to the first through hole 80. When the top cover 77 is laminated on the housing body 76, the inner peripheral surface of the hole 77a is continuous with the inner peripheral surface of the first through hole 80. Screw through holes 77b are provided at both ends of the hole 77a.

The top cover 77 is attached to the housing body 76 using screws 94. The screw 94 passes through the screw through hole 77b of the top cover 77 and is screwed into the screw receiving portion 80b of the housing body 76. As a result, the top cover 77 is attached to the housing body 76.

An O-ring 74 is provided around the upper opening 79a of the accommodating portion 79. Therefore, the top cover 77 is provided on the upper end surface of the housing body 76 to tightly close the upper opening 79a of the accommodating portion 79.

The impeller 72 is housed in the pump chamber 84. The impeller 72 has a disk shape and has a rotation shaft 72a at the center of rotation. The rotating shaft 72a straddles between the heat receiving plate 78 and the top cover 77, and is rotatably supported by the heat receiving plate 78 and the top cover 77. The heat receiving plate 78 is provided with a support portion 72b that supports the rotating shaft 72a.

The motor 73 includes a rotor 73a and a stator 73b. The rotor 73a is formed in a ring shape. The rotor 73a is coaxially fixed to the upper surface of the impeller 72 and housed in the pump chamber 84. Inside the rotor 73a, magnets 73c in which a plurality of positive electrodes and a plurality of negative electrodes are alternately magnetized are fitted. The rotor 73a is designed to rotate integrally with the impeller 72.

The stator 73b is housed in a recess 77c formed on the upper surface of the top cover 77. The recess 77c goes inside the rotor 73a. Therefore, the stator 73b is coaxially housed inside the rotor 73a.

The control board 75 is supported on the upper surface of the top cover 77. The control board 75 is electrically connected to the stator 73b and controls the motor 73. The energization of the stator 73b is performed at the same time, for example, when the power of the portable computer 10 is turned on. By this energization, a rotating magnetic field is generated in the circumferential direction of the stator 73b, and this magnetic field and the magnet 73c fitted in the rotor 73a are magnetically coupled. As a result, torque is generated between the stator 73b and the magnet 73c along the circumferential direction of the rotor 73a, and the impeller 72 rotates in the clockwise direction indicated by the arrow in FIG.

A back plate 93 is provided on the upper surface of the top cover 77. The back plate 93 covers the stator 73b and the control board 75. The back plate 93 has a function of preventing the liquid refrigerant exuded from the pump housing 71 from leaking.

The back plate 93 is attached to the pump housing 71 using screws 94. The back plate 93 may be omitted as long as the liquid refrigerant does not exude from the top cover 77.

As shown in FIGS. 2 and 5, the pump 70 is placed on the printed circuit board 23 so that the heat receiving surface 83 covers the CPU 24 from above. In the present embodiment, the pump 70 is placed on the printed circuit board 23 so that the central portion of the heat receiving surface 83 overlaps the central portion 26e of the upper surface 26 of the IC chip 24b.

As shown in FIG. 7, the heat receiving surface 83 has a guide 130. The guide 130 defines a facing region 131 facing the upper surface 26 of the IC chip 24b on the heat receiving surface 83. The guide 130 indicates, but is not limited to, the entire outer edge of the facing region 131. For example, the guide 130 may indicate only a portion of the outer edge of the facing region 131.

As shown in FIG. 2, the central portion 131a of the facing region 131 overlaps the central portion of the heat receiving surface 83. The central portion 131a of the facing region 131 and the central portion 26e of the upper surface 26 of the IC chip 24b face each other. The facing region 131 faces a position in the pump chamber 84 away from the rotation shaft 72a of the impeller 72. The flow velocity of the liquid refrigerant is high in the pump chamber 84 at a position away from the rotation shaft 72a of the impeller 72.

The guide 130 is formed together when the heat receiving plate 78 is molded by the outer shape punching process. The mold used for the outer shape punching process is provided with a convex portion corresponding to the outer edge of the facing region 131. As a result, the outer edge of the facing region 131 of the heat receiving surface 83 is grooved by the convex portion of the mold biting into it. This groove serves as a guide 130.

The method of forming the guide 130 by the mold is an example, and the method is not limited to this. The guide 130 may be drawn, for example, on the entire outer edge of the facing area 131, a part of the outer edge, or the entire facing area 131 by a separate printing means. As the printing means, there is a plate in which holes corresponding to the entire outer edge of the facing area 131, a part of the outer edge, or the entire facing area 131 are formed. In FIGS. 5 and 7, the groove-shaped guide 130 formed by the mold is shown. Further, the guide 130 is not limited to a solid line shape, and may be, for example, a broken line shape.

As shown in FIG. 5, the bottom wall 21a of the first housing 21 is provided with a boss portion 95 at a position corresponding to the first through hole 80 at each corner of the pump housing 71. The boss portion 95 projects upward from the bottom wall 21a, and the printed circuit plate 23 is superposed on the tip surfaces of the boss portions 95 via the reinforcing plate 96.

The portable computer 10 includes a mounting mechanism 100. The mounting mechanism 100 has a function of fixing the pump 70 to the bottom wall 21a of the first housing 21. The mounting mechanism 100 includes a plurality of inserts 101, a plurality of screws 102, a plurality of coil springs 103, and a plurality of C rings 104.

The insert 101 has a tubular shape that can be inserted into the second through hole 82. The insert 101 has an overhanging portion 101a at one end. The overhanging portion 101a projects horizontally outward from the outer peripheral surface of the insert 101 along the circumferential direction. The overhanging portion 101a has a size of being caught around the second through hole 82. A groove 105 along the circumferential direction is formed on the outer peripheral surface of the other end of the insert 101. The coil spring 103 has a size in which the insert 101 can be inserted.

The mounting mechanism 100 fixes the pump 70 to the first housing 21 as follows. First, one insert 101 is inserted inside each coil spring 103. Then, each insert 101 is inserted into the hole 77a of the top cover 77 from the end on the groove 105 side. The insert 101 is pushed in until the end on the groove 105 side penetrates the second through hole 82. At this time, the coil spring 103 is caught around the second through hole 82.

When the groove 105 penetrates the second through hole 82, the C ring 104 is fitted into the groove 105. As a result, the insert 101 is attached to the pump 70 with the overhanging portion 101a urged by the coil spring 103.

Then, the grease 110 is applied to the inside of the facing region 131 with the guide 130 of the heat receiving surface 83 as a guide. The grease 110 is an example of the heat transfer member referred to in the present invention. Other heat transfer members include a cool sheet and the like. As a method of applying the grease 110, there are a method of applying the grease 110 and a method of applying the grease 110 so as to print by a plate having holes corresponding to the facing regions 131. The grease application method is not limited to the above two methods.

Then, the tip portion of each insert 101 on the groove 105 side is arranged on each boss portion 95. As a result, the pump 70 is installed on the CPU 24 with the facing region 131 and the upper surface 26 of the IC chip 24b facing each other.

Then one screw 102 is inserted into each insert 101. Each screw 102 penetrates the insert 101 and is screwed into the boss portion 95. As a result, the insert 101 is fixed on the printed circuit board 23. The facing region 131 of the heat receiving surface 83 is pressed against the upper surface 26 of the IC chip 24b by the elasticity of the coil spring 103. Therefore, the heat receiving surface 83 is reliably thermally connected to the IC chip 24b via the grease 110.

As shown in FIG. 2, the circulation path 120 includes a first pipe 121, a second pipe 122, and a pipe constituting the heat radiating unit main body 51 of the heat radiating unit 50. The first pipe 121 is connected between the discharge pipe 91 of the pump housing 71 and the refrigerant inlet 53 of the heat radiating unit 50. The second pipe 122 connects the suction pipe 90 of the pump housing 71 and the refrigerant outlet of the heat radiating unit 50.

Therefore, the liquid refrigerant circulates between the pump 70 and the heat radiating unit 50 through the first pipe 121 and the second pipe 122. The pipe constituting the heat radiating unit main body 51 of the heat radiating unit 50 constitutes the heat radiating unit 50 and forms a part of the circulation path 120. That is, the circulation path 120 is thermally connected to the heat radiating unit 50.

The pump chamber 84 of the pump 70, the reserve tank 86, the heat radiating portion 50, and the circulation path 120 are filled with a liquid refrigerant inside.

Next, the operation of the cooling device will be described. While using the portable computer 10, the IC chip 24b of the CPU 24 generates heat. The heat generated by the IC chip 24b is transferred to the heat receiving surface 83. Since the pump chamber 84 of the pump housing 71 and the reserve tank 86 are filled with the liquid refrigerant, the liquid refrigerant absorbs most of the heat transferred to the heat receiving surface 83.

The energization of the stator 73b of the motor 73 is performed at the same time as the power of the portable computer 10 is turned on. As a result, torque is generated between the rotor 73a and the magnet 73c of the rotor 73a, and the rotor 73a rotates with the impeller 72. When the impeller 72 rotates, the liquid refrigerant in the pump chamber 84 is pressurized and discharged from the discharge pipe 91, and is guided to the heat radiating portion 50 through the first pipe 121. In the heat radiating unit 50, the heat absorbed by the liquid refrigerant is transferred to the heat radiating unit main body 51 and the heat radiating fins 52.

When the impeller 62 of the electric fan 60 rotates while the portable computer 10 is in use, cooling air is blown from the discharge port 61a of the fan casing 61 toward the heat radiating unit 50. This cooling air passes between the radiating fins 52. As a result, the heat radiating unit main body 51 and the heat radiating fins 52 are cooled, and most of the heat transferred to the heat radiating unit main body 51 and the heat radiating fins 52 is multiplied by the flow of the cooling air to the first housing from the exhaust port 25. It is released to the outside of body 21.

The liquid refrigerant cooled by the heat radiating unit 50 is guided to the suction pipe 90 of the pump housing 71 through the second pipe 122. The liquid refrigerant is discharged from the suction pipe 90 into the reserve tank 86. The liquid refrigerant returned to the reserve tank 86 absorbs the heat of the IC chip 24b again.

Since the downstream end of the suction pipe 90 and the communication port 87 are immersed in the liquid refrigerant stored inside the reserve tank 86, the liquid refrigerant inside the reserve tank 86 is from the communication port 87 to the pump chamber 84. It flows into the inside of.

The liquid refrigerant guided to the inside of the pump chamber 84 absorbs the heat of the IC chip 24b again and is sent to the heat radiating unit 50 via the discharge pipe 91. As a result, the heat generated in the IC chip 24b is sequentially transferred to the heat radiating unit 50 via the circulating liquid refrigerant, and is discharged from the heat radiating unit 50 to the outside of the portable computer 10.

In the portable computer 10 configured in this way, the heat receiving surface 83 has a guide 130. Therefore, since the guide 130 serves as a guide for applying the grease 110, the grease 110 can be efficiently and surely interposed between the heat receiving surface 83 and the upper surface 26 of the IC chip 24b. That is, the IC chip 24b and the heat receiving surface 83 are reliably thermally connected. Therefore, the variation in the cooling performance of the cooling device 40 is reduced.

Further, since the grease 110 is not applied to the upper surface 26 of the IC chip 24b of the CPU 24 mounted on the printed circuit board 23, the application of the grease 110 may be hindered by the electronic components mounted around the CPU 24. Absent. That is, the grease 110 can be efficiently interposed between the upper surface 26 of the IC chip 24b and the heat receiving surface 83.

Further, the facing region 131 of the heat receiving surface 83 faces a position in the pump chamber 84 where the flow velocity of the liquid refrigerant is high. Therefore, the IC chip 24b is efficiently cooled.

Next, the guide according to the second embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 8, the guide 130 has a display unit 132 facing each corner portion 26a to 26d of the upper surface 26 of the IC chip 24b. The guide 130 is not provided in any part other than each display unit 132. That is, the guide 130 shows only the corner portion of the facing region 131 by each display unit 132. In the second embodiment, the same effect as in the first embodiment can be obtained. In FIG. 8, the guide 130 formed in a groove shape by the mold is shown.

Next, the guide according to the third embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 9, the heat receiving surface 83 has a guide 133 instead of the guide 130. The guide 133 is provided at a position facing the central portion 26e of the upper surface 26 of the IC chip 24b. The guide 133 has a cross shape. The cross shape is an example of the shape of the guide 133. The shape of the guide 133 may be, for example, a point.

The guide 133 may be formed by a mold as shown in the first embodiment. Alternatively, it may be drawn by printing means. In FIG. 9, the guide 133 drawn by the printing means is shown.

According to the third embodiment, when the grease 110 is applied to the heat receiving surface 83 by the dispenser, the dispenser can be easily positioned at the central portion 131a of the facing region 131 by installing the dispenser in accordance with the guide 133. it can. That is, the grease 110 can be efficiently interposed between the upper surface 26 of the IC chip 24b and the heat receiving surface 83. The opposite region 131 is indicated by a chain double-dashed line in FIG.

Next, the guide according to the fourth embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 10, the heat receiving surface 83 has a first guide 140 and a second guide 141 instead of the guide 130. The first guide 140 shows the entire outer edge of the facing region 131 of the heat receiving surface 83. The first guide 140 may indicate a part of the outer edge of the facing region 131. The first guide 140 is, but is not limited to, a solid line. For example, it may be in the shape of a broken line.

The second guide 141 is located in the central portion 131a of the facing region 131. That is, the second guide 141 faces the central portion 26e of the upper surface 26 of the IC chip 24b. The second guide 141 has a cross shape. The cross shape is an example. For example, it may be a point.

The first guide 140 and the second guide 141 may be formed by a mold as shown in the first embodiment. Alternatively, it may be drawn by printing means. In FIG. 10, a groove-shaped first guide 140 and a second guide 141 formed by the mold are shown.

When the grease 110 is applied to the facing region 131 of the heat receiving surface 83, it may be applied using a dispenser as shown in the first embodiment. Alternatively, it may be applied for printing by a plate having holes corresponding to the facing regions 131.

According to the fourth embodiment, in addition to the same effect as that of the first embodiment, when the grease 110 is applied by the dispenser, the dispenser is opposed to the dispenser by installing the dispenser in accordance with the second guide 141. It can be easily positioned at the central portion 131a of the region 131. That is, the grease 110 can be efficiently interposed between the upper surface 26 of the IC chip 24b and the heat receiving surface 83.

Next, the guide according to the fifth embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the fourth embodiment, and the description thereof will be omitted.

As shown in FIG. 11, the first guide 140 has a display unit 142 facing each corner portion 26a to 26d of the upper surface 26 of the IC chip 24b. The first guide 140 is not provided in any part other than each display unit 142. That is, the first guide 140 shows only the corner portion of the facing region 131 by each display unit 142. In the fifth embodiment, the same effect as in the fourth embodiment can be obtained.

Next, the guide according to the sixth embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the first embodiment, and the description thereof will be omitted.

As shown in FIG. 12, the heat receiving surface 83 has a guide 150 instead of the guide 130. The guide 150 shows the entire outer edge of the coating area 151. The guide 150 may indicate a part of the outer edge of the coating area 151. Further, the guide 150 may be on a broken line instead of a solid line. The coating area 151 may be formed by a mold as shown in the first embodiment. Alternatively, it may be drawn by printing means. In FIG. 12, a groove-shaped guide 150 formed by a mold is shown.

The coating area 151 has a planar circular shape and indicates an area to which the grease 110 is applied. The coating area 151 is an example of an area in which the heat transfer member referred to in the present invention is provided. The coating area 151 is smaller than the facing area 131. In FIG. 12, the opposite region 131 is indicated by a two-dot chain line.

The coating area 151 is formed by spreading the grease 110 applied to the coating area 151 between the heat receiving surface 83 and the upper surface 26 of the IC chip 24b when the pump 70 is fixed on the printed circuit board 23. It has a size considering that it can be extended over the entire facing region 131.

When the grease 110 is applied to the application area 151, it may be applied by a dispenser as shown in the first embodiment. Alternatively, it may be applied for printing by a plate having holes corresponding to the application area 151. The planar shape of the coating area 151 is not limited to a circle.

According to the sixth embodiment, by indicating the coating area 151 by the guide 150, the grease 110 can be efficiently interposed between the upper surface 26 of the IC chip 24b and the heat receiving surface 83 with the guide 150 as a guide. .. Further, since the coating area 151 has a size in consideration of the spreading grease 110, the amount of wasted grease 110 can be suppressed.

Next, the guide according to the seventh embodiment of the present invention will be described with reference to FIG. The same reference numerals are given to the configurations having the same functions as those of the fourth embodiment, and the description thereof will be omitted.

As shown in FIG. 13, the partition member 85 is provided so that the rotation shaft 72a of the impeller 72 in the pump chamber 84 is located at the center of the heat receiving plate 78. The pump 70 is fixed on the printed circuit board 23 so that the position of the impeller 72 away from the rotation shaft 72a in the pump chamber 84 faces the upper surface 26 of the IC chip 24b. The flow velocity of the liquid refrigerant is high in the pump chamber 84 at a position away from the rotation shaft 72a of the impeller 72.

The facing region 131 is provided at a position where the central portion 131a thereof is separated from the central portion of the heat receiving surface 83. That is, the first guide 140 and the second guide 141 are provided at positions closer to the corners of the heat receiving surface 83.

In the seventh embodiment, even if the upper surface 26 of the IC chip 24b faces the position of the corner of the heat receiving surface 83, the first guide 140 and the second guide 141 are used as a guide for the IC chip 24b. The grease 110 can be efficiently interposed between the upper surface 26 and the heat receiving surface 83. Further, the facing region 131 faces a position in the pump chamber 84 where the flow velocity of the liquid refrigerant is high. Therefore, the IC chip 24b is efficiently cooled.

In the seventh embodiment, the heat receiving surface 83 has the first guide 140 and the second guide 141, but is not limited thereto. The guide may indicate, for example, the entire outer edge or part of the outer edge of the facing region 131. Alternatively, only the central portion 131a of the facing region 131 may be shown. Alternatively, only the central portion 26e of the upper surface 26 of the IC chip 24b may be shown. Alternatively, the entire outer edge or a part of the outer edge of the coating area 151 may be shown.

As shown in the first to seventh embodiments, the pump 70 is not limited to a structure in which a heat receiving plate 78 is provided as a heat receiving portion for heat connection with the IC chip 24b. For example, the housing body 76 may be formed into a bottomed shape having a bottom wall as a heat receiving portion by using a metal material having excellent thermal conductivity such as an aluminum alloy.

In this case, a guide is provided on the bottom wall of the housing body 76. When the housing body 76 is molded by die casting or the like, the guide may be formed together with the housing body 76 when it is molded. In this case, the mold for molding the housing 76 is the entire outer edge of the facing region 131, a part of the outer edge, the central portion 131a of the facing region 131, and the IC chip 24b, as shown in the first to seventh embodiments. It has a convex portion corresponding to the corner portions 26a to 26d of the upper surface 26, the central portion 26e of the upper surface 26 of the IC chip 24b, or the entire outer edge of the coating area 151 or a part of the outer edge. In this way, the depth of the guide groove can be adjusted simply by scraping the convex portion. In other words, when adjusting the depth of the guide, it is not necessary to change the mold significantly. This also applies when a guide is formed on the heat receiving plate 78 depending on the mold.

When the housing body 76 and the heat receiving portion are integrally molded by die casting or the like, the mold may have a shape having a concave portion forming a guide instead of a convex portion forming the guide. In this way, the guide formed on the heat receiving surface 83 has a shape that protrudes toward the CPU 24 side.

<figref num="1">The perspective view of the portable computer which concerns on 1st Embodiment of this invention.</figref><figref num="2">Top view of the cooling device housed in the first housing.</figref><figref num="3">An exploded perspective view of the pump.</figref><figref num="4">Perspective view of the pump housing of the pump.</figref><figref num="5">Sectional view of the pump shown along line F5-F5 in Figure 2.</figref><figref num="6">Top view of the housing body.</figref><figref num="7">Top view of the heat receiving surface.</figref><figref num="8">The plan view of the heat receiving surface which concerns on 2nd Embodiment of this invention.</figref><figref num="9">The plan view of the heat receiving surface which concerns on 3rd Embodiment of this invention.</figref><figref num="10">The plan view of the heat receiving surface which concerns on 4th Embodiment of this invention.</figref><figref num="11">The plan view of the heat receiving surface which concerns on 5th Embodiment of this invention.</figref><figref num="12">The plan view of the heat receiving surface which concerns on 6th Embodiment of this invention.</figref><figref num="13">The plan view of the heat receiving surface which concerns on 7th Embodiment of this invention.</figref>

Code description

10 ... Portable computer (electronic device), 21 ... 1st housing (housing), 24 ... CPU (heating element), 26 ... Top surface (thermal connection surface), 26a ~ 26d. .. corner, 26e ... center (center of heating element), 50 ... heat dissipation, 70 ... pump, 71 ... pump housing (housing), 72 ... impeller, 73. .. motor, 78 ... heat receiving plate (heat receiving part), 83 ... heat receiving surface, 84 ... pump chamber, 110 ... grease (heat transfer member), 120 ... circulation path, 130 .. Guide, 131 ... facing area (area facing the heating element), 131a ... central part (central part of the area facing the heating element), 132 ... display, 133 ... guide, 140 ... 1st guide, 141 ... 2nd guide, 142 ... Display, 150 ... Guide, 151 ... Coating area (area where the heat transfer member is provided).