JPH10303582A - Cooing device of circuit module and portable information equipment mounting circuit module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of a circuit module that fully secures the cooling performance of a circuit element, at the same time, compactly forms a cooling member including a fan unit, and can reduce the occupation area of the cooling member for a circuit board. SOLUTION: A circuit module 19 has a circuit board 20 with a reverse side 20a and a surface 20b, a TCP(tape carrier package) 25 that is packaged to the reverse side of the circuit board, a heat reception part 37 for escaping the heat of the TCP in the direction of the surface of the circuit board, a cold plate 35 that is arranged on the surface of the circuit board and receives the heat of the TCP via the heat reception part, and a fan unit 55 with a rotor 57 and a fan case 58 for accommodating the rotor. The fan case 58 is in contact with a cold plate 35 in a posture for arranging the rotary shaft of the rotor along the thickness direction of the circuit board and has a channel path 64 where a cool wind is circulated when the rotor 57 rotates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling device for a circuit module having a circuit element that generates heat and a portable information device such as a portable computer having a housing in which the circuit module is housed, and more particularly to a circuit for the device. The present invention relates to a structure for promoting heat radiation of an element.

[0002]

2. Description of the Related Art In recent years, the performance of book-type or notebook-type portable computers has been remarkably improved, and in particular, the processing speed of CPUs mounted on computers tends to be further increased. This type of CPU is composed of a semiconductor package having a number of input / output pins. The multi-pin semiconductor package is mounted on a circuit board, and the circuit board is housed in a portable computer housing together with a pack-like device such as a hard disk drive or a CD-ROM drive.

In recent portable computers that are becoming smaller and lighter, a so-called TCP (Tape) capable of connecting multiple poles in a small mounting space is used as the CPU.
A semiconductor package called Carrier Package is used. This TCP includes a carrier made of a flexible resin film, an IC chip supported by the carrier,
And a large number of leads soldered to the IC chip. The leads are made of a thin metal such as a copper foil, and the tips of these leads are soldered to pads on a circuit board.

[0004] This kind of TCP is exposed to the outside without the IC chip being resin-molded. for that reason,
Since the mechanical strength is lower than that of a resin-molded package such as PGA, a heat sink cannot be directly attached to TCP itself. For this reason, when housing a TCP having a large heat value in a housing of a portable computer, it is necessary to enhance the heat radiation performance of the TCP inside the housing.

As a method of promoting the heat radiation of the TCP, conventionally, a through-hole connected to an IC chip is formed in a circuit board on which the TCP is mounted, and a TC of the circuit board is formed.
There is known a device in which a heat radiating member called a cold plate and a fan unit for forcibly cooling the heat radiating member are attached to a surface opposite to P.

The heat dissipating member is made of a metal material having excellent thermal conductivity, such as copper or brass, and has a convex heat receiving portion that enters the through hole. The heat receiving portion is bonded to the IC chip, so that the heat of the IC chip is released to the heat radiating member through the heat receiving portion.

The heat dissipating member is provided with a large number of fins for securing a heat dissipating area. The fin is exposed inside the housing. Therefore, the IC escaped to the heat dissipation member
Part of the heat of the chip is naturally radiated into the housing via the fins.

The fan unit has a rotor that is driven to rotate, and a fan frame that supports the rotor. The fan frame is screwed to an end of the heat radiating member with the rotation axis of the rotor being horizontal, and the fin is located at a position facing the rotor. Therefore, when the rotor of the fan unit is driven to rotate, the heat dissipating members and fins are located on the path of the cooling air flowing toward the rotor, and the heat dissipating properties of these heat dissipating members and fins are promoted. I have.

[0009]

However, according to the above-mentioned conventional structure, since the heat dissipating member has a large number of fins exposed inside the housing, the heat dissipating member becomes heavier and larger by these fins. In addition, a support portion for mounting a fan unit for forced air cooling must be formed at a position facing the fins, and the size of the heat radiation member is increased by the amount of the support portion.

Therefore, the area occupied by the heat dissipating member on the circuit board increases, and a sufficient area for mounting the above-mentioned pack-like device and other circuit components on the circuit board can be secured. There is a problem that it disappears.

Further, according to the above configuration, since the heat radiating member becomes heavy and large, the weight of the housing may be increased accordingly. At the same time, since the fan unit is arranged in an upright posture on the circuit board, the fan unit protrudes largely in the thickness direction of the circuit board. For this reason, a wide space for accommodating the fan unit must be secured inside the housing, and the thickness of the housing increases.

Therefore, the housing becomes heavy and large, which goes against the recent demand for reducing the weight of the portable computer. A first object of the present invention is to provide a circuit capable of forming a heat radiating member including a fan unit compact while sufficiently securing the heat radiating performance of a circuit element, and reducing the area occupied by the heat radiating member with respect to a circuit board. It is to obtain a cooling device for a module.

A second object of the present invention is to make it possible to form the heat radiating member including the fan unit in a compact form while sufficiently securing the heat radiating performance of the circuit element, and to reduce the size and weight of the housing. It is to obtain a shape information device.

[0014]

In order to achieve the first object, a cooling device for a circuit module according to claim 1 is provided on a first surface and on a side opposite to the first surface. A circuit board having a second surface; a heat-generating circuit element mounted on the first surface of the circuit board; and dissipating heat of the circuit element in the direction of the second surface of the circuit board. A transmitting means; a heat-conductive radiating member disposed on the second surface of the circuit board and receiving heat of the circuit element via the transmitting means; a rotor driven to rotate; and a fan accommodating the rotor And a fan unit attached to the heat radiating member. The fan case of the fan unit is in contact with the heat radiating member in such a manner that the rotation axis of the rotor extends along the thickness direction of the circuit board, and the fan case allows cooling air to flow when the rotor rotates. It is characterized in that it has a flow passage that communicates.

In such a configuration, when the circuit element generates heat, the heat of the circuit element is released to the heat radiating member via the transmission means. Since the fan case of the fan unit is attached to the heat radiating member, a part of the heat released to the heat radiating member is directly transmitted to the fan case.

When the fan unit rotor is driven,
Cooling air flows through the flow passage inside the fan case, and the fan case is forcibly cooled. Therefore, the heat of the circuit element transmitted to the fan case is removed by being multiplied by the cooling air flowing through the flow passage, and the heat radiating member and thus the circuit element are radiated positively.

In this case, since the fan case through which the cooling air flows is attached to the heat radiating member, the heat transfer from the heat radiating member to the fan case becomes good, and the heat radiating member can be efficiently cooled. For this reason, the heat released to the heat radiating member can be efficiently released to the outside without using a special fin as in the related art, and the heat radiating member can be reduced in size by eliminating the need for the fin. Therefore, the area occupied by the heat radiating member with respect to the circuit board can be reduced.

In addition, since the rotor of the fan unit is housed in the fan case with its rotation axis extending along the thickness direction of the circuit board, the fan case is arranged along the second surface of the circuit board. Will be arranged in a proper posture. Therefore, the fan unit does not protrude greatly in the thickness direction of the circuit board, and the thickness of the entire circuit module including the fan unit can be reduced.

In order to achieve the first object, a first aspect is provided.
3. The cooling device for a circuit module according to 3 includes a first surface, a second surface located on the opposite side to the first surface,
A circuit board having through holes opened in the first and second surfaces; and a circuit element mounted on the first surface of the circuit board and generating heat during operation and facing the through holes; A heat-conductive heat-dissipating member disposed on the second surface of the circuit board and including a heat-receiving portion that enters the through-hole and receives heat of the circuit element; a rotor that is driven to rotate; and a fan that houses the rotor And a fan unit attached to the heat radiating member. The fan case of the fan unit is in contact with the heat radiating member in a posture in which the rotation axis of the rotor is along the thickness direction of the circuit board, and the fan case has a surface opposite to the heat radiating member. And a discharge port opened on the peripheral surface adjacent to the suction port, and cooling air flows through the inside of the fan case when the rotor rotates.

In such a configuration, when the circuit element generates heat, the heat of the circuit element is released to the heat radiating member through the heat receiving portion. Since the fan case of the fan unit is attached to the heat radiating member, a part of the heat released to the heat radiating member is directly transmitted to the fan case.

When the rotor of the fan unit is driven,
Cooling air is taken into the fan case through the suction port, and the cooling air flows inside the fan case toward the discharge port. For this reason, the heat of the circuit element transmitted to the fan case is multiplied by the cooling air flowing through the inside of the fan case and taken out to the outside, so that the heat radiating member and thus the circuit element are actively cooled.

In this case, since the fan case through which the cooling air flows is attached to the heat radiating member, the heat transfer from the heat radiating member to the fan case becomes good, and the heat radiating member can be efficiently cooled. For this reason, the heat released to the heat radiating member can be efficiently released to the outside without using a special fin as in the related art, and the heat radiating member can be reduced in size by eliminating the need for the fin. Therefore, the area occupied by the heat radiating member with respect to the circuit board can be reduced.

In addition, since the rotor of the fan unit is housed in the fan case with the rotation axis thereof oriented along the thickness direction of the circuit board, the fan case may be arranged along the second surface of the circuit board. Will be arranged in a proper posture. Therefore, the fan unit does not protrude greatly in the thickness direction of the circuit board, and the thickness of the entire circuit module including the fan unit can be reduced.

In order to achieve the first object, a first aspect is provided.
6. A cooling device for a circuit module according to claim 6, wherein the circuit board has a first surface and a second surface located on an opposite side to the first surface; and a first surface of the circuit board. A heat-generating circuit element mounted on the circuit board; and a number of heat-dissipating circuit elements disposed at positions corresponding to the circuit element so as to penetrate the circuit board in the thickness direction and dissipate heat of the circuit element in the direction of the second surface of the circuit board A thermal via; a thermal conductive heat dissipating member disposed on the second surface of the circuit board and receiving heat of the circuit element via the thermal via; a rotor driven to rotate; And a fan unit attached to the heat radiating member. The fan case of the fan unit is in contact with the heat radiating member in a posture in which the rotation axis of the rotor is along the thickness direction of the circuit board, and the fan case has a surface opposite to the heat radiating member. A suction port, a discharge port opened on a peripheral surface adjacent to the suction port, and an air guide path for guiding cooling air sucked from the suction port to the discharge port when the rotor rotates. It is characterized by having.

In such a configuration, when the circuit element generates heat, the heat of the circuit element is released to the heat radiating member through the thermal via. Since the fan case of the fan unit is attached to the heat radiating member, a part of the heat released to the heat radiating member is directly transmitted to the fan case.

When the rotor of the fan unit is driven,
Cooling air is taken into the flow passage inside the fan case through the suction port, and the cooling air flows through the flow passage toward the discharge port. Therefore, the heat of the circuit element transmitted to the fan case is multiplied by the cooling air flowing through the flow passage and taken out to the outside, so that the heat radiating member and thus the circuit element are actively cooled.

In this case, since the fan case through which the cooling air flows is attached to the heat radiating member, the heat transfer from the heat radiating member to the fan case becomes good, and the heat radiating member can be efficiently cooled. For this reason, the heat released to the heat radiating member can be efficiently released to the outside without using a special fin as in the related art, and the heat radiating member can be reduced in size by eliminating the need for the fin. Therefore, the area occupied by the heat radiating member with respect to the circuit board can be reduced.

In addition, since the rotor of the fan unit is accommodated in the fan case with the rotation axis thereof oriented along the thickness direction of the circuit board, the fan case may be arranged along the second surface of the circuit board. Will be arranged in a proper posture. Therefore, the fan unit does not protrude greatly in the thickness direction of the circuit board, and the thickness of the entire circuit module including the fan unit can be reduced.

[0029] To achieve the second object, a second aspect is provided.
The portable information device described in No. 0 is a circuit board having a first surface and a second surface located on a side opposite to the first surface, and is mounted on the first surface of the circuit board. A circuit module including a circuit element that generates heat; a transmission unit for dissipating heat of the circuit element in a direction of a second surface of the circuit board; and a transmission unit disposed on the second surface of the circuit board. A heat-conducting heat-dissipating member that receives the heat of the circuit element through the heat-dissipating member; a fan unit attached to the heat-dissipating member;
A box-shaped housing for housing the circuit module including the heat dissipating member and the transmitting means and the fan unit; The fan unit includes a rotor that is driven to rotate and a fan case that houses the rotor. The fan case is configured such that the rotation axis of the rotor is aligned with a thickness direction of the circuit board. It is characterized in that it has a flow passage in contact with the heat radiation member and through which the cooling air flows when the rotor rotates.

In such a configuration, when the circuit element generates heat, the heat of the circuit element is released to the heat radiating member via the transmission means. Since the fan case of the fan unit is attached to the heat radiating member, a part of the heat released to the heat radiating member is directly transmitted to the fan case.

When the rotor of the fan unit is driven,
Cooling air flows through the flow passage inside the fan case, and the fan case is forcibly cooled. Therefore, the heat of the circuit element transmitted to the fan case is multiplied by the cooling air flowing through the flow passage and taken out to the outside, so that the heat radiating member and thus the circuit element are actively cooled.

In this case, since the fan case through which the cooling air flows is attached to the heat radiating member, the heat transfer from the heat radiating member to the fan case becomes good, and the heat radiating member can be efficiently cooled. For this reason, the heat released to the heat radiating member can be efficiently released to the outside without using a special fin as in the related art, and the heat radiating member can be reduced in size by eliminating the need for the fin. Therefore, the area occupied by the heat radiating member with respect to the circuit board can be reduced.

In addition, since the rotor of the fan unit is accommodated in the fan case with the rotation axis thereof oriented along the thickness direction of the circuit board, the fan case can be arranged along the second surface of the circuit board. Will be arranged in a proper posture. Therefore, the fan unit does not protrude greatly in the thickness direction of the housing, and the thickness of the circuit module including the fan unit can be reduced. Therefore, it is not necessary to secure a large space inside the housing, and the housing can be formed thinner and more compact than before.

[0034]

FIG. 1 to FIG. 6 in which a first embodiment of the present invention is applied to a portable computer.
It will be described based on the following. FIG. 1 discloses a book-type portable computer 1. The portable computer 1 includes a main unit 2 and a display unit 3 supported by the main unit 2.

The main unit 2 has a housing 4 made of synthetic resin. The housing 4 includes a bottom wall 4a, left and right side walls 4
b, 4c, a front wall 4d, a rear wall 4e, and an upper wall 4f. The housing 4 is divided into a lower housing 5 and an upper housing 6 detachably connected to the lower housing 5. The lower housing 5 has the bottom wall 4a and four peripheral walls 5a extending upward from the peripheral edge of the bottom wall 4a. The upper housing 6 has the upper wall 4f and four peripheral walls 6a extending downward from the peripheral edge of the upper wall 4f. The peripheral wall 5a of the lower housing 5 and the peripheral wall 6a of the upper housing 6 cooperate with each other to form the side walls 4b, 4
c, a front wall 4d and a rear wall 4e.

The upper wall 4f of the housing 4 has a palm rest 8,
And a keyboard mounting portion 9. Palm rest 8
Is located at the front end of the housing 4. The keyboard mounting section 9 is located behind the palm rest 8. FIG.
As shown in FIG. 2, the keyboard mounting portion 9 is formed of a depression that is recessed toward the inside of the housing 4, and an opening 10 that is continuous with the inside of the housing 4 is formed at the bottom of the keyboard mounting portion 9. Have been.

The keyboard 11 is provided with a keyboard 11.
Is installed. The keyboard 11 has a keyboard panel 13 having many key tops 12 and a metal reinforcing plate 14 stacked on the back surface of the keyboard panel 13. Keyboard panel 13 and reinforcing plate 14
Has a size such that it fits tightly inside the keyboard mounting portion 9. The reinforcing plate 14 is exposed inside the housing 4 through the opening 10.

As shown in FIG. 1, the display unit 3
Is a display housing 16 having a flat box shape,
And a liquid crystal display device 17 housed in the display housing 16. Display housing 16
Has a front surface on which a display window 18 is opened.
8, the display screen 17a of the liquid crystal display device 17 is exposed to the outside.

The display unit 3 is connected to the rear end of the housing 4 via a hinge device (not shown). for that reason,
The display unit 3 includes a closed position that covers and hides the palm rest 8 and the keyboard 11, and the palm rest 8 and the keyboard 11.
Is rotatable over an open position where the image is exposed.

As shown in FIG. 5, a pack-like device (not shown) such as a circuit module 19 and a CD-ROM drive is accommodated in the housing 4. The circuit module 19 has a circuit board 20. The circuit board 20 is screwed to the bottom wall 4a of the lower housing 5,
It is arranged horizontally so as to be parallel to the bottom wall 4a.

The circuit board 20 has a back surface 2 as a first surface.
0a and a surface 20b as a second surface.
The back surface 20 a of the circuit board 20 faces the bottom wall 4 a of the housing 4. The surface 20 b of the circuit board 20 faces the reinforcing plate 14 of the keyboard 11. The back surface 20a and the front surface 20b of the circuit board 20 have a DRAM
Various circuit components 21 are mounted.

At the rear end of the surface 20b of the circuit board 20,
A plurality of connectors 22 for connecting peripheral devices or power cords are mounted. These connectors 22
They are arranged in a line in the width direction of the housing 4 and are exposed to the outside of the housing 4 through the rear wall 4e.

As shown in FIGS. 3 to 5, the circuit board 2
0 is provided with a TCP as a circuit element that generates heat.
(Tape Carrier Package) 25 is mounted. TC
P25 constitutes the CPU of the portable computer 1, and is located at the rear of the housing 4. This T
The power consumption during operation of the CP 25 increases in response to the increase in the processing speed of the portable computer 1.
Accordingly, the calorific value of the TCP 25 is also very large.

The TCP 25 includes a carrier 26 made of a flexible resin film, an IC chip 27 supported at the center of the carrier 26 and generating heat during operation, and a number of leads 28 formed on the carrier 26. ing. The carrier 26 has a square shape with four edges. The leads 28 are made of copper foil, and adjacent leads 28 are arranged in parallel with a narrow pitch.

The lead 28 has a first end 28a and a second end 28b. First end 2 of lead 28
8a is soldered to a bump of the IC chip 27. The soldered portions between the leads 28 and the IC chip 27 are covered with a potting resin 29. The second end 28 b of the lead 28 extends outward from the edge of the carrier 26.

The TCP 25 comprises the lead 28 and the IC chip 2
7 with the soldering part facing away from the circuit board 20;
The back surface 2 of the circuit board 20 in a so-called face-up posture
0a. Back surface 20a of this circuit board 20
, A large number of pads 30 are arranged, and the second ends 28 b of the leads 28 are soldered to these pads 30.

As shown in FIGS. 3A and 4, the circuit board 20 has a square through hole 33 at a position corresponding to the mounting portion of the TCP 25. The through hole 33 has an opening shape larger than the planar shape of the IC chip 27 and penetrates the circuit board 20 in the thickness direction. This through hole 33
Faces the IC chip 27. The circuit board 20 has four through holes 34. Through hole 34
Are arranged at diagonal positions of a square around the through hole 33, and are located outside the mounting area of the TCP 25.

On the surface 20b of the circuit board 20, a cold plate 35 as a heat radiating member is arranged. The cold plate 35 has a flat plate main body 36. The plate body 36 is made of a copper-based alloy material having excellent heat conductivity, and has an opening shape of the through-hole 33 and TC
It has a square plate shape larger than the plane shape of P25.

The plate body 36 has a lower surface 36 a facing the circuit board 20 and an upper surface 36 b as a heat radiating surface located on the opposite side to the circuit board 20. At the center of the lower surface 36a of the plate body 36, a heat receiving portion 37 projecting downward is integrally formed. The heat receiving section 37
The heat receiving portion 37 is fitted into the through hole 33 of the circuit board 20, and the lower surface of the heat receiving portion 37 is a flat heat receiving surface 38. The heat receiving surface 38 is bonded to the upper surface of the IC chip 27 via a heat conductive silver paste or an adhesive 39.

When the IC chip 27 generates heat,
The heat of the IC chip 27 is mainly transmitted to the heat receiving portion 37 and is released in the direction of the surface 20b of the circuit board 20. Therefore, in the case of the present embodiment, the heat receiving portion 37 of the cold plate 35 and the through hole 33 of the circuit board 20 constitute a transmission means for releasing the heat of the IC chip 27.

The plate body 36 has bosses 42 having insertion holes 41 at four corners. Insertion hole 41
Are the lower surface 36a and the upper surface 36 of the plate body 36, respectively.
b, and these insertion holes 41 are
0 through hole 34.

A TCP cover 44 is disposed on the back surface 20a of the circuit board 20. The TCP cover 44 is an IC
This is for covering and protecting the soldered portions of the chip 27 and the leads 28 of the TCP 25 and the pads 30 of the circuit board 20. The TCP cover 44 is made of a thermally conductive metal material such as brass or an aluminum alloy. The TCP cover 44 has a square shape having substantially the same size as the plate main body 36, and the center of the upper surface of the TCP cover 44 faces the IC chip 27.

The TCP cover 44 has bosses 45 at four corners on the upper surface. The boss portions 45 are respectively provided with screw holes 4
6. The screw hole 46 is connected to the insertion hole 41 of the plate body 36 via the through hole 34 of the circuit board 20.

As shown in FIG. 3A, screws 48 are inserted into the insertion holes 41 of the plate body 36 from above the circuit board 20, respectively. The screw 48 penetrates through the insertion hole 41 and the through-hole 34 and the screw hole 46 of the TCP cover 44.
Screwed into. By this screwing, the cold plate 35 and the TCP cover 44 are tightened in a direction approaching each other with the circuit board 20 interposed therebetween, and are held by the circuit board 20.

At the center of the upper surface of the TCP cover 44, an elastic sheet 50 having thermal conductivity is adhered. The elastic sheet 50 is a rubber-like elastic body obtained by adding alumina to a silicone resin, and is sandwiched between the TCP cover 44 and the IC chip 27. Therefore, when the IC chip 27 generates heat, part of the heat of the IC chip 27 is released to the TCP cover 44 via the elastic sheet 50.

As shown in FIG. 4, the TCP cover 44
A thermistor 51 for measuring the ambient temperature of the IC chip 27 is provided. The thermistor 51 is supported by a flexible wiring board 52. This thermistor 51
Is embedded in the elastic sheet 50 and faces the center of the TCP cover 44. Therefore, the thermistor 51 is mainly a TCP that transmits heat of the IC chip 27.
The temperature of the cover 44 is measured.

The wiring board 52 is provided with a TCP cover 44.
Is derived outside. The lead-out end of the wiring board 52 is connected to the circuit board 20. Therefore, temperature information of the TCP cover 44 measured by the thermistor 51 is input to a control circuit on the circuit board 20.

As shown in FIGS. 3 to 6, an electric fan unit 55 is supported on the upper surface 36b of the plate body 36. The fan unit 55 is arranged below the keyboard 11 at a position adjacent to the left side wall 4 b of the housing 4.

As shown in FIG. 3B, the fan unit 55 includes a rotor 5 having a plurality of fan blades 56.
7 and a fan case 58 that rotatably accommodates the rotor 57. The fan case 58 has a case body 60 and a rotor cover 61 connected to the case body 60. The case body 60 and the rotor cover 61 are made of a metal material having excellent thermal conductivity, such as an aluminum alloy.

The case body 60 includes a bottom surface 60a and an upper surface 60.
b and four peripheral surfaces 60c connected to the bottom surface 60a and the upper surface 60b. Bottom surface 60a of case body 60
And the upper surface 60b is provided on the upper surface 36 of the plate body 36.
It has a flat square shape having substantially the same size as a.

A recess 62 is formed in the center of the upper surface 60b of the case body 60. The concave portion 62 is for accommodating the rotor 57, and the rotor 57 is rotatably supported at the bottom of the concave portion 62 via a flat brushless motor 63. The rotation axis R1 of the rotor 57
Extends in a direction orthogonal to the bottom surface 60a of the case main body 60.

Therefore, as shown in FIG. 3A, the height H of the case body 60 along the direction of the rotation axis R1 of the rotor 57 is much smaller than the depth D and the width W. The case body 60 has a small flat box shape, and the bottom surface 60 a of the case body 60 is overlapped with the upper surface 36 b of the plate body 36.

The rotor cover 61 has a flat plate shape. The rotor cover 61 is provided on the upper surface 60 of the case body 60.
b. The rotor cover 61 cooperates with the recess 62 to form a cooling air flow passage 64.
The rotor 57 is located in the flow passage 64.

The rotor cover 61 is provided with a cooling air suction port 65.
have. The suction port 65 is positioned coaxially with the rotor 57, and the suction port 65 is
It is connected to. A cooling air outlet 66 is formed on one peripheral surface 60c of the case main body 60.
The discharge port 66 continues to the flow passage 64 and faces the peripheral surface of the rotor 57.

The above-mentioned motor 63 serving as a drive source of the rotor 57
Is connected to the circuit board 20 via a lead wire 68 (shown in FIG. 6).
It is connected to the. The motor 63 is driven based on a signal sent from the control unit of the circuit board 20 when the temperature of the TCP cover 44 measured by the thermistor 51 exceeds, for example, 80 ° C. .

Therefore, the rotor 5 is connected via the motor 63.
When the fan 7 is driven to rotate, cooling air is introduced into the flow passage 63 inside the fan case 58 through the suction port 65, and the cooling air flows along the bottom of the recess 62, and then flows through the discharge port 66. The air is discharged to the outside of the fan case 58.

As shown in FIGS. 3A and 3B, the case body 60 of the fan case 58 has a pair of bosses 70. The boss 70 is located at a diagonal corner of the case body 60. The boss portions 70 are respectively provided with the screws 4
8 have screw insertion holes 71, which are connected to the through holes 34 of the circuit board 20.

For this reason, the fan case 58 is fixed to the plate body 36 using the screws 48, and the fan case 58 and the IC chip 27 of the TCP 25 are fixed.
Are opposed to each other with the cold plate 35 interposed therebetween.

As shown in FIG. 4, between the upper surface 36b of the plate body 36 and the bottom surface 60a of the fan case 58,
An elastic sheet 73 having thermal conductivity is interposed. The elastic sheet 73 is a rubber-like elastic body obtained by adding alumina to a silicone resin, and is sandwiched between the upper surface 36b of the plate body 36 and the bottom surface 60a of the fan case 58 with the tightening of the screws 48. ing. Therefore, the fan case 58 is in contact with the cold plate 35 via the elastic sheet 73 without any gap, so that heat can be efficiently transmitted from the cold plate 35 to the fan case 58.

As shown in FIG. 4, the fan unit 55
Is mounted on the cold plate 35 in a posture in which the rotation axis R1 of the rotor 57 is along the thickness direction of the circuit board 20, that is, in a posture orthogonal to the circuit board 20.
That is, the flat fan unit 55 is connected to the circuit board 20.
It is arranged in a posture lying substantially horizontally so as to be parallel to the above, and the amount of upward projection of the circuit board 20 is suppressed to be small.

As shown in FIG. 5, the rotor cover 61 of the fan case 58 is arranged in parallel with the reinforcing plate 14 of the keyboard 11. A wind guide passage 75 is formed between the rotor cover 61 and the reinforcing plate 14, and the suction port 65 is opened in the wind guide passage 75.

The peripheral surface 60 c of the case body 60 with the discharge port 66 opened is opposed to the left side wall 4 b of the housing 4. The side wall 4b has a plurality of exhaust ports 76 as shown in FIGS. 2 and 6, and the exhaust ports 76 and the discharge ports 66 of the case main body 60 face each other.

A wind guide 77 made of synthetic resin is adhered to the rotor cover 61 of the fan case 58. The air guide 77 extends from the discharge port 66 of the fan case 58 toward the side wall 4b, and connects the discharge port 66 and the exhaust port 76.

In such a configuration, while the portable computer 1 is operating, the power consumption of the TCP 25 causes
The C chip 27 generates heat. The IC chip 27 is attached to the heat receiving portion 37 of the cold plate 35 by a heat conductive adhesive 39.
, The heat of the IC chip 27 is
It is mainly escaped to the heat receiving section 37. And this heat receiving section 37
The heat of the IC chip 27 released to the circuit board 20 is diffused to the plate body 36 on the surface 20b of the circuit board 20.

A fan case 58 having thermal conductivity is provided on the upper surface 36 b of the plate body 36 via an elastic sheet 73.
Is attached, a part of the heat diffused to the plate body 36 is transmitted to the fan case 58 as it is.

When the ambient temperature of the IC chip 27 exceeds 80 ° C., the rotor 57 is driven to rotate via the motor 63. By the rotation of the rotor 57, air inside the housing 4 is sucked through the suction port 65, and the air becomes cooling air and flows through the flow passage 64 inside the fan case 58.
The fan case 58 is forcibly cooled by the flow of the cooling air. As a result, the heat of the IC chip 27 transmitted to the fan case 58 is removed by being multiplied by the cooling air flowing through the flow passage 64, and the cold plate 35 and the IC chip 27 are actively radiated. Become.

Further, since the TCP cover 44 disposed on the back surface 20a of the circuit board 20 is in contact with the IC chip 27 via the heat conductive elastic sheet 50, a part of the heat of the IC chip 27 is It is also escaped to the TCP cover 44. Since the TCP cover 44 is connected to the plate body 36 of the cold plate 35 via four screws 48 penetrating the circuit board 20, the heat of the IC chip 27 released to the TCP cover 44 is It is transmitted to the plate body 36 through the screw 48.

Therefore, the heat radiation of the TCP cover 44 can be enhanced by the cooling air flowing through the flow passage 64 of the fan case 58, and the TCP cover 44 and the circuit board 20
The heat of the IC chip 27 hardly stays in between.

The cooling air exchanged in the process of flowing through the flow passage 64 is guided to the discharge port 66 of the fan case 58,
The air is guided to the exhaust port 76 through the air guide 77, and is discharged to the outside of the housing 4 from the exhaust port 76. For this reason, the cooling air heated by the heat exchange is not released into the inside of the housing 4, and the temperature inside the housing 4 can be prevented from rising.

Further, since the cooling air flows through the flow passage 64 partitioned from the inside of the housing 4, the flow path of the cooling air inside the housing 4 is concentrated at one location, and the TCP 25 that generates heat is concentrated. Can be cooled. Therefore, TCP25
The influence of heat on other circuit components and the pack-shaped device located around the device can be reduced, which is convenient in the portable computer 1 in which the positions of the heat-generating components in the housing 4 are integrated in one place.

According to the portable computer 1 having such a configuration, the fan case 58 forcedly cooled by the cooling air flowing through the flow passage 64 is superposed on the upper surface 36 b of the cold plate 35 via the elastic sheet 73. Thus, heat transfer from the cold plate 35 to the fan case 58 is improved, and the cold plate 35 can be efficiently cooled.

Further, since the fan case 58 faces the IC chip 27 with the cold plate 35 interposed therebetween, the heat transfer path from the IC chip 27 to the fan case 58 is shortened. Therefore, the heat of the IC chip 27 can be efficiently transmitted to the fan case 58 and released to the outside of the housing 4 by the cooling air flowing through the flow passage 64.

As a result, a special fin for securing the heat radiation area of the cold plate 35 is not required, and it is not necessary to form a support portion for supporting the fan unit 55 at the end of the cold plate 35.
Accordingly, the size of the cold plate 35 can be reduced. Therefore, in a state where the cold plate 35 and the fan unit 55 are incorporated in the circuit board 20, the area occupied by the cold plate 35 with respect to the circuit board 20 can be reduced, and the size of the circuit board 20 can be reduced without increasing the size of the circuit board 20. 20 can be increased.

Further, since the fan unit 55 is superposed on the upper surface 36b of the cold plate 35 with the rotation axis R1 of the rotor 57 orthogonal to the circuit board 20, the flat fan case 58 Surface 20
b. Therefore, the fan unit 55 does not protrude significantly above the circuit board 10, and the thickness of the circuit module 19 including the fan unit 55 can be made thin and compact.

Therefore, it is not necessary to secure a large space inside the housing 4, and the housing 4 can be formed thinner and more compact than before. Note that the present invention is not limited to the first embodiment, and FIGS. 7A and 7B show a second embodiment of the present invention.

The second embodiment is different from the first embodiment in the configuration for mainly releasing the heat of the IC chip 27 in the direction of the surface 20b of the circuit board 20. The configuration is the same as that of the first embodiment. Therefore, in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 7A, the circuit board 20
Has a large number of thermal vias 81 penetrating the circuit board 20 in the thickness direction. Thermal via 81
At a position corresponding to the mounting portion of the TCP 25, they are arranged in a matrix.

The thermal vias 81 are connected to the circuit board 2
0, a first opening end 81a opened on the back surface 20a, and a second opening end 81 opened on the front surface 20b of the circuit board 20.
b. The inner surfaces of the thermal vias 81 are covered with plated layers 82 each having thermal conductivity.
The plating layer 82 has first and second opening ends 81a,
It has reached 81b.

The IC chip 27 of the TCP 25 is
9 is adhered to the back surface 20 a of the circuit board 20. The adhesive 39 is interposed between the IC chip 27 and the first opening end 81a of the thermal via 81.

Plate body 36 of cold plate 35
Has a flat plate shape. The lower surface 36a of the plate body 36 is overlaid on the front surface 20b of the circuit board 20 via the elastic sheet 73, and the second open end 81b of the thermal via 81 is in contact with the elastic sheet 73.
Therefore, the lower surface 36 a of the plate body 36 of the present embodiment is a heat receiving surface that receives the heat of the IC chip 27.

According to such a configuration, the IC chip 27 that generates heat is attached to the back surface 2 of the circuit board 20 via the adhesive 39.
0a, and a first opening end 81a of the thermal via 81 is opened on the back surface 20a.
The heat of the C chip 27 is mainly released to the surface 20 b of the circuit board 20 through the thermal via 81.

Since the plate body 36 of the cold plate 35 is overlaid on the front surface 20b of the circuit board 20 with the elastic sheet 73 interposed therebetween, the heat of the IC chip 27 released through the thermal via 81 is reduced by the second heat. From the opening end 81b of the plate body 36. And
The heat of the IC chip 27 diffused into the plate body 36 is transmitted to the fan case 58 similarly to the first embodiment.
The flow path 64 inside the fan case 58
Is discharged to the outside of the housing 4 by heat exchange with cooling air flowing through the housing 4.

Therefore, also in the second embodiment, the heat of the IC chip 27 can be efficiently released to the fan case 58 via the cold plate 35, and the same effect as in the first embodiment can be obtained. Obtainable.

FIG. 8 discloses a third embodiment of the present invention. The third embodiment differs from the first embodiment mainly in the configuration of the cold plate 91, and the other configurations of the TCP 25 and the fan unit 55 are the same as those in the first embodiment. The same is true. Therefore, in the third embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 8, the back surface 2 of the circuit board 20
A pair of TCPs 25a and 25b are mounted on 0a. These TCPs 25a and 25b are adjacent to each other. On the surface 20b of the circuit board 20, a bare semiconductor chip 92 that is not resin-molded and is called a bare chip is mounted. The semiconductor chip 92 is located near the one TCP 25a.

The circuit board 20 has a pair of through holes 93a, 93
b. The through holes 93a and 93b are provided in the TCP2.
They are arranged at positions corresponding to 5a and 25b. These through holes 93a and 93b have openings larger than the IC chip 27 of the TCPs 25a and 25b, and each of the through holes 93a and 93b generates heat.
It faces the C chip 27.

The cold plate 91 is mounted on the circuit board 2
0 on the surface 20b. Cold plate 9
1 has a flat plate body 95. The plate body 95 is made of a copper-based alloy material having excellent thermal conductivity, and has a flat plate shape having a size covering the mounting portions of the pair of TCPs 25a and 25b.

The plate body 95 has a lower surface 95a facing the circuit board 20, and an upper surface 95b as a heat radiating surface located on the opposite side of the circuit board 20. On the lower surface 95a of the plate body 95, a pair of heat receiving portions 96a and 96b projecting downward are integrally formed. The heat receiving portions 96a, 96b are provided with through holes 93a, 93b of the circuit board 20.
The lower surfaces of these heat receiving portions 96a and 96b are flat heat receiving surfaces 97. The heat receiving surface 97
It is in contact with the upper surface of IC chip 27 via a thermally conductive silver paste or adhesive 98.

Therefore, when the IC chips 27 of the TCPs 25a and 25b generate heat, the heat of the IC chips 27 is transmitted mainly to the heat receiving portions 96a and 96b and is released in the direction of the surface 20b of the circuit board 20. .

The plate body 95 is provided with the semiconductor chip 9.
2 is provided integrally with the extension portion 100 extended so as to cover the second portion. The extension 100 has a contact surface 101 that is in contact with the semiconductor chip 92, and the heat of the semiconductor chip 92 is transmitted to the extension 100 by this contact. A plurality of mounting seats 102 are formed on the outer peripheral portion of the plate body 95 including the extension portion 100. These mounting seats 102 are supported on the circuit board 20 via screws 103.

The fan unit 55 is disposed on the upper surface 95b of the plate body 95. The fan unit 55 is installed at a position corresponding to one TCP 25a, and is supported by the circuit board 20 together with the TCP cover 44 that covers the TCP 25a. for that reason,
The other TCP 25 b is exposed outside the circuit board 20 without being covered by the TCP cover 44.

According to such a configuration, since the plurality of IC chips 27 that generate heat are bonded to the heat receiving portions 96a and 96b of the cold plate 91 via the adhesive 98,
The heat of the IC chip 27 is released mainly to the plate body 95 of the cold plate 91 through the heat receiving portions 96a and 96b. Also, when the bare semiconductor chip 92 generates heat,
The heat of the semiconductor chip 92 is applied to the contact surface 1 of the extension 100.
01 to the plate body 95.

The heat transmitted to the plate body 95 is
Similarly to the first embodiment, the heat is transmitted to the fan case 58 and is discharged to the outside of the housing 4 by heat exchange with cooling air flowing through the flow passage 64 inside the fan case 58.

Therefore, also in the third embodiment, heat from a plurality of heat sources such as a pair of TCPs 25a and 25b and a semiconductor chip 92 is efficiently transferred to fan case 58 via one cold plate 91. The heat can be released, and the heat radiation of the TCPs 25a and 25b and the semiconductor chip 92 can be improved.

Note that the portable information device according to the present invention is not limited to a notebook-type portable computer, but can be similarly applied to other portable information devices such as a text creation device.

[0106]

According to the first, thirteenth and sixteenth aspects of the present invention, the heat of the circuit element released to the heat radiating member is:
Since the heat is transmitted to the fan case as it is and is removed by multiplying the cooling air flowing through the inside of the fan case, the heat radiating member and thus the heat of the circuit element can be actively radiated. At the same time, the heat transfer from the heat dissipating member to the fan case becomes good, and the heat dissipating member can be efficiently cooled, so that the heat dissipated to the heat dissipating member can be efficiently discharged to the outside without using a special fin as in the conventional case. Can be released. Therefore, the heat dissipating member can be reduced in size by eliminating the need for the fin, and the area occupied by the heat dissipating member on the circuit board can be reduced.

In addition, the fan case is provided on the second side of the circuit board.
The fan unit does not protrude significantly in the thickness direction of the circuit board,
There is an advantage that the thickness of the circuit module including the fan unit can be reduced.

According to the twentieth aspect, the heat of the circuit element released to the heat radiating member is transmitted to the fan case as it is, and is removed by multiplying the cooling air flowing inside the fan case. Therefore, heat radiation of the heat radiating member and thus the circuit element can be positively performed. At the same time, the heat transfer from the heat dissipating member to the fan case becomes good, and the heat dissipating member can be efficiently cooled, so that the heat dissipated to the heat dissipating member can be efficiently discharged to the outside without using a special fin as in the conventional case. Can be released. Therefore, the heat dissipating member can be reduced in size by eliminating the need for the fin, the area occupied by the heat dissipating member on the circuit board can be reduced, and the mounting area on the circuit board can be increased.

In addition, the fan case is provided on the second circuit board.
Therefore, the fan unit does not protrude greatly in the thickness direction of the housing, and the thickness of the circuit module including the fan unit can be reduced. Therefore, it is not necessary to secure a large space inside the housing, and the housing can be made thin and compact accordingly.

[Brief description of the drawings]

FIG. 1 is an exemplary perspective view of a portable computer according to a first embodiment of the present invention;

FIG. 2 is an exemplary perspective view of a portable computer showing a left end portion of a housing having an exhaust port opened;

FIG. 3A is an exploded perspective view showing a positional relationship between a TCP, a cold plate, a TCP cover, and a fan unit with respect to a circuit board. (B) is an exploded perspective view showing the fan unit.

FIG. 4 is a sectional view of a TCP mounting portion.

FIG. 5 is an exemplary cross-sectional view of the portable computer illustrating a state in which a circuit module is housed in a housing;

FIG. 6 is a cross-sectional view of the portable computer illustrating a positional relationship between a discharge port of the fan unit and an exhaust port of the housing.

FIG. 7A is a sectional view of a mounting portion of a TCP according to a second embodiment of the present invention. (B) is a sectional view of a thermal via on a circuit board.

FIG. 8 is a sectional view of a circuit module according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 4 ... Housing 19 ... Circuit module 20 ... Circuit board 20a ... 1st surface (back surface) 20b ... 2nd surface (front surface) 25 ... Circuit element (TCP) 33, 37, 81 ... Transmission means (through hole, heat reception) 55, fan unit 57, rotor 58, fan case 64, flow path 65, suction port 66, discharge port R1, rotation

Claims (27)

[Claims] 1. A circuit board having a first surface and a second surface opposite to the first surface; and a heat generating device mounted on the first surface of the circuit board. A circuit element; transmission means for radiating heat of the circuit element in the direction of the second surface of the circuit board; and heat transfer means disposed on the second surface of the circuit board for transferring heat of the circuit element through the transmission means. A heat-conducting heat-dissipating member that receives the rotor; a rotor that is driven to rotate; and a fan case that houses the rotor. The fan case has a fan unit attached to the heat-dissipating member. The fan case of the fan unit is in contact with the heat radiating member in a posture in which the rotation axis of the rotor is along the thickness direction of the circuit board. The fan case has a flow passage through which cooling air flows when the rotor rotates. Characterized by having Cooling device of the circuit module. 2. The cooling device for a circuit module according to claim 1, wherein the fan case has a box shape that is flat in the direction of the rotation axis of the rotor. 3. The cooling device for a circuit module according to claim 1, wherein the circuit element and the fan unit face each other with the heat radiation member interposed therebetween. 4. The fan case according to claim 2, wherein the fan case includes a suction port opened on a surface opposite to the heat radiation member, a discharge port opened on a peripheral surface adjacent to the suction port, A cooling device for a circuit module, comprising: 5. The cooling device for a circuit module according to claim 1, wherein the fan case is made of a metal material having thermal conductivity. 6. The heat radiation member according to claim 5, wherein the heat radiation member has a flat heat radiation surface parallel to the second surface of the circuit board, and the fan case has a flat bottom surface facing the heat radiation surface. Wherein the heat radiating surface and the bottom surface are in contact with each other via a soft elastic sheet having thermal conductivity. 7. The communication device according to claim 1, wherein the transmitting means is provided at a position corresponding to the circuit element, through a through-hole penetrating the circuit board in a thickness direction, and integrally projecting from the heat radiating member. A cooling device for a circuit module, comprising: a heat receiving portion that enters a hole and faces the circuit element. 8. The method according to claim 7, wherein the through hole is
Having an opening shape larger than the planar shape of the circuit element,
The cooling device for a circuit module, wherein the heat receiving portion has a heat receiving surface adhered to the circuit element via a thermally conductive adhesive. 9. The circuit element according to claim 7, wherein the circuit element is formed of a flexible resin film carrier, a heat-generating IC chip supported by the carrier, and an electric chip formed on the carrier. And a number of leads connected to the tape carrier package. The tape carrier package has a connection portion between the IC chip and the lead facing away from the circuit board. A cooling device for a circuit module, wherein the cooling device is mounted on a first surface of the circuit board in an attitude, and the IC chip faces a through hole of the circuit board. 10. The transmission device according to claim 1, wherein the transmission unit includes a plurality of thermal vias penetrating the circuit board in a thickness direction at positions corresponding to the circuit elements. It has a first open end facing the circuit element and a second open end facing the heat radiating member, and a soft elastic material having thermal conductivity is provided between the second open end and the heat radiating member. A cooling device for a circuit module, wherein a sheet is interposed. 11. The device according to claim 1, wherein the circuit element is covered with a cover having thermal conductivity.
The circuit module cooling device, wherein the cover is disposed on the first surface of the circuit board, and is connected to the heat radiating member via a screw penetrating the circuit board. 12. The circuit module cooling device according to claim 11, wherein the cover and the circuit element are in contact with each other via an elastic sheet having thermal conductivity. 13. A circuit board having a first surface, a second surface located on the opposite side of the first surface, and a through-hole opened in the first and second surfaces. A circuit element mounted on the first surface of the circuit board and generating heat during operation and facing the through hole; and a circuit element disposed on the second surface of the circuit board and entering the through hole to form the circuit. A heat-conducting heat-dissipating member including a heat-receiving portion that receives heat of the element; a rotor unit that includes a rotor that is driven to rotate and a fan case that accommodates the rotor, the fan case being attached to the heat-dissipating member; A fan case of the fan unit is in contact with the heat radiating member in a posture in which a rotation axis of the rotor is aligned with a thickness direction of the circuit board, and the fan case is different from the heat radiating member. A suction opening on the opposite side Mouth and provided with a discharge port opened in the circumferential surface adjacent to the suction port, a cooling device of a circuit module, characterized in that the internal cooling air of the fan case during rotation of the rotor flows. 14. The fan case according to claim 13, wherein the fan case is made of a metal material having thermal conductivity.
The cooling device for a circuit module, wherein the fan case and the heat radiating member are in contact with each other via a soft elastic sheet having thermal conductivity. 15. The fan case according to claim 14, wherein the fan case has a cooling air flow passage connected to the suction port and the discharge port.
A cooling device for a circuit module, wherein said cooling device faces each other with said heat radiating member interposed therebetween. 16. A circuit board having a first surface and a second surface located on a side opposite to the first surface; and a heat generator mounted on the first surface of the circuit board. A circuit element; and a number of thermal vias disposed through the circuit board in a thickness direction at positions corresponding to the circuit element, and dissipating heat of the circuit element in the direction of the second surface of the circuit board; A heat conductive heat dissipating member disposed on the second surface of the circuit board and receiving heat of the circuit element via the thermal via; a rotor driven to rotate; and a fan case accommodating the rotor. And a fan unit attached to the heat radiating member. The fan case of the fan unit is arranged so that a rotation axis of the rotor is aligned with a thickness direction of the circuit board. In contact with the heat dissipating member The fan case has a suction port opened on a surface opposite to the heat radiating member, a discharge port opened on a peripheral surface adjacent to the suction port, and a suction port which is sucked from the suction port when the rotor rotates. A cooling passage for guiding cooling air to the discharge port. 17. The thermal via according to claim 16, wherein the thermal via has a first opening end facing the circuit element and a second opening end facing the heat dissipation member. The first open end of the thermal via is adhered to the circuit element via an adhesive having thermal conductivity, and the second open end of the thermal via is formed of a soft elastic sheet having thermal conductivity. A cooling device for a circuit module, wherein said cooling device is in contact with said heat radiating member through said heat radiating member. 18. The fan case according to claim 17, wherein the fan case is made of a metal material having thermal conductivity.
The cooling device for a circuit module, wherein the fan case and the heat radiating member are in contact with each other via a soft elastic sheet having thermal conductivity. 19. The cooling device for a circuit module according to claim 18, wherein the fan case and the circuit element face each other with the heat radiation member interposed therebetween. 20. A circuit board having a first surface and a second surface located on a side opposite to the first surface, and a circuit element generating heat mounted on the first surface of the circuit board. A transmission module for dissipating heat of the circuit element in the direction of the second surface of the circuit board; and a circuit module disposed on the second surface of the circuit board and via the transmission means. A heat-conducting heat-dissipating member that receives the heat of the heat-dissipating member; a fan unit attached to the heat-dissipating member; and a box-shaped housing that houses the circuit module including the heat-dissipating member and the transmitting means and the fan unit. In the portable information device, the fan unit includes a rotor that is driven to rotate, and a fan case that houses the rotor, and the fan case has a rotation axis of the rotor in a thickness direction of the circuit board. Along Together we are in contact with the heat radiation member in posture,
A portable information device comprising a flow passage through which cooling air flows when the rotor rotates. 21. The device according to claim 20, wherein the housing has a bottom wall and a peripheral wall connected to the bottom wall, and the circuit board of the circuit module has a first surface formed by the bottom surface. A portable information device which is arranged in a posture facing a wall in parallel with the bottom wall. 22. The fan unit according to claim 20, wherein the fan case of the fan unit has a box shape that is flat in the axial direction of the rotor, and the fan case and the circuit element are provided inside the housing. 3. The portable information device according to claim 1, wherein the portable information device faces each other with the heat radiation member interposed therebetween. 23. The method according to claim 22, wherein the fan case is made of a metal material having thermal conductivity.
This fan case has a suction port opened on a surface opposite to the heat dissipation member, and a discharge port opened on a peripheral surface adjacent to the suction port. machine. 24. The device according to claim 23, wherein the peripheral wall of the housing has an exhaust port connected to the inside of the housing, and the discharge port of the fan case faces the exhaust port. Portable information equipment. 25. The portable information device according to claim 24, wherein the exhaust port of the housing and the discharge port of the fan case are connected to each other via a wind guide. 26. The circuit device according to claim 21, wherein the circuit element is covered with a cover having thermal conductivity, and the cover includes a first surface of the circuit board and a bottom wall of the housing. A portable information device, wherein the portable information device is disposed between the heat dissipation member and a screw that penetrates the circuit board. 27. The circuit element according to claim 20, wherein the circuit element is formed of a carrier made of a flexible resin film, a heat-producing IC chip supported by the carrier, and the carrier. And a plurality of leads connected to the tape carrier package. The tape carrier package has a connection part between the IC chip and the lead facing away from the circuit board. A portable information device mounted on a first surface of the circuit board.