JP3659634B2 - Electronics - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electronic apparatus having a cooling module for electronic components such as a CPU.
[0002]
[Prior art]
In recent years, CPUs installed in electronic devices have been improved in operating clock frequency, have become faster and higher performance, and the amount of heat generated has been increasing. In order to maintain CPU performance Needs to cool the CPU. As a cooling method, a method of radiating heat from the CPU by connecting a heat radiating member such as a heat sink to the upper surface of the CPU is employed.
[0003]
In a conventional electronic device such as a computer, a circuit board is built in a housing, and a CPU is mounted on the board. A plurality of electrodes are formed in a matrix on the bottom surface of the CPU, and the electrodes of the CPU are connected to the circuit board by soldering or the like. A heat sink for dissipating heat generated by the CPU is mounted above the CPU via a heat transfer sheet having good heat transfer. The heat sink is formed of a material having good thermal conductivity such as aluminum, and a support portion for fixing the heat sink to the circuit board is integrally formed. Since the support portion of the heat sink is fixed to the circuit board via screws, the CPU is mounted so as to be sandwiched between the circuit board and the heat sink.
[0004]
In the conventional cooling module as described above, the heat sink is screwed to a housing or a circuit board by a screw, and a force related to the screw is applied to the CPU as it is. In addition, while suppressing various dimensional errors such as CPU dimensional errors, variations in mounting height due to dimensional errors of CPU electrodes such as solder bumps and solder balls, manufacturing tolerances of heat sinks, etc. In order to ensure a good thermal connection, the CPU is heavily loaded.
[0005]
Furthermore, it has become possible for recent electronic devices such as computers to adopt a method of making them according to the user's purpose of use and specifications according to the user's preference, or the user to freely change the specifications. For example, with respect to the CPU, it is required that ones having different operation clock frequencies can be easily replaced. For this reason, a method of mounting a CPU mounting socket on a circuit board and mounting the CPU in this socket so as to be detachable has become mainstream. The socket is soldered and mounted on the circuit board with a plurality of solder balls or solder bumps arranged in a matrix. Further, a PGA (PIN GRID ARRAY) type CPU is employed for easy attachment / detachment. In this type of CPU, a plurality of pins are arranged in a matrix on the lower surface of the CPU as electrodes of the CPU, and each CPU pin is inserted into a socket and mounted. Such a CPU mounting method can satisfy a user's request.
[0006]
The socket described above is usually reflow soldered. In reflow soldering, solder paste is first applied on electrode pads for mounting components on a circuit board, and then passed through a high-temperature reflow furnace to melt and solder the solder paste. The circuit board is surface-mounted on both sides, and the circuit is formed by two-step reflow soldering, where components (sockets, etc.) are reflow soldered to the circuit board surface, and then other components are reflow soldered to the back side of the circuit board. Component mounting is performed on both sides of the board. Usually, the circuit board is placed in the reflow furnace with the mounting surface as the upper surface.
At this time, even when the socket is normally mounted by reflow soldering to the front surface, when reflow soldering to the back surface, the circuit board is placed in the reflow furnace. ) The solder connecting the components mounted on is melted again. In a state where the solder is melted, the socket is inclined in a direction away from the circuit board due to the weight of the socket.
[0008]
When mounting a socket, the mounting height and inclination of the socket vary greatly depending on the quality of soldering of the electrodes. Furthermore, the height dimension from the circuit board surface after mounting the CPU to the upper surface of the CPU varies considerably due to the degree of insertion of the CPU pins into the socket, the dimensional error of the CPU, and the dimensional error of the socket.
[0009]
When a heat sink such as that described above is connected to a CPU employing such a mounting method and screwed to a circuit board, a screw fixing force for stopping the heat sink is applied to the CPU or socket as it is. Therefore, when a load more than an allowable amount is applied to the CPU and socket, problems such as cracks, breakage, and circuit destruction of the electrodes of the CPU and socket are adversely affected.
[0010]
An example of solving such a problem is, for example, Japanese Patent Application Laid-Open No. 2001-110967 “Heat dissipation structure of electronic element”. The cooling structure of an electronic device disclosed in Japanese Patent Application Laid-Open No. 2001-110967 is a cooling in which a heat transfer block is brought into contact with an electronic device mounted on a substrate, and heat is diffused from the electric heating block to a heat diffusion plate via a heat pipe. In the structure, a structure is disclosed in which coil springs are respectively interposed between fixing screws provided at four corners of the block and the block when the heat transfer block is mounted on the substrate. A method of absorbing an error in the height dimension of an electronic element with such a structure has been proposed. However, the configuration disclosed in Japanese Patent Laid-Open No. 2001-110967 leads to an increase in the number of parts, which is not preferable in terms of assemblability, the number of parts, and cost.
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above points, and even if an error occurs in the mounting dimensions of an electronic component or an electronic component, the electronic component can be satisfactorily cooled without being damaged, and the assembling property can be improved. The purpose is to provide a good electronic device for improvement, reduction in the number of parts, and cost reduction.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, in the electronic device according to claim 1, a main body, a circuit board built in the main body and mounted with an electronic component that generates heat during operation, and mounted on the circuit board to support the fan unit. A cooling module that includes a fan case and a heat receiving plate that is supported by the fan case and is thermally connected to the electronic component to transfer heat from the electronic component and is formed in a leaf spring shape. It is characterized by that.
[0013]
An electronic apparatus according to a second aspect of the present invention includes a main body, a circuit board that is built in the main body and on which electronic components that generate heat during operation are mounted, a fan case that is mounted on the circuit board and supports the fan unit, and the fan case A heat receiving plate that is supported and thermally connected to the electronic component to transfer heat from the electronic component and is formed in a leaf spring shape, an inlet that is provided on the upper surface of the fan case and into which air flows, and a fan case And a cooling module having a discharge port that discharges the air that is provided on the side surface.
[0014]
An electronic apparatus according to a third aspect of the present invention includes a main body, a circuit board that is built in the main body and on which electronic components that generate heat during operation are mounted, a fan case that is mounted on the circuit board and supports the fan unit, and the fan case And a cooling module including a heat receiving plate that is integrally formed and thermally connected to the electronic component to transfer heat from the electronic component and is formed into a leaf spring shape.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments according to the present invention applied to an electronic device such as a notebook computer will be described below with reference to the drawings. FIG. 1 is a perspective view of a computer. The computer 1 has a main body 4. The main body 4 has an upper case 2 and a lower case 3. A keyboard 5 is disposed on the upper surface of the main body 4. A hinge portion 6 is provided at the rear portion of the main body 4, and the display portion 7 is connected to the main body 4 through the hinge portion 6 so as to be rotatable. An opening 8 is formed on the side surface of the main body 4.
[0017]
FIG. 2 is an exploded perspective view of the CPU. A circuit board 10 is built in the computer 1. The circuit board 10 is provided with electrode pads 11 arranged in a matrix. A CPU socket 12 for mounting a CPU 16, which is an electronic component, is mounted on the electrode pad 11. The CPU socket 12 is a BGA type socket in which a plurality of solder balls 15 are formed on a base 13, and the solder balls 15 are soldered to the pads 11. A plurality of holes 14 are formed in a matrix on the upper surface of the CPU socket 12.
[0018]
A plurality of electrode pins 19 are formed on the lower surface of the base 17 of the CPU 16 to form a PGA type CPU. An element 18 is mounted on the base 17, and the element 18 and the pin 19 are electrically connected.
[0019]
FIG. 3 is a perspective view of the cooling module according to the first embodiment. A cooling module 20 is mounted on the CPU socket 12 and the CPU 16 mounted on the circuit board 10. In the cooling module 20, a fan case 21 and a heat receiving plate 22 are integrally formed of a metal material such as aluminum. The fan case 21 is formed in a housing shape so as to cover the rotor 25, the fan 26 and a motor to be described later, and a suction port 23 is formed on the upper surface 21a. The fan 26 and the rotor 25 are exposed to the suction port 23. As the fans 26 rotate, the air around the cooling module 20 flows into the suction port 23. Further, a discharge port 24 is formed on the side surface of the fan case 21. The air flowing in from the suction port 23 is discharged from the discharge port 24. When the circuit board 10 and the cooling module 20 are mounted on the main body 4, the discharge port 24 of the cooling module 20 is disposed so as to face the opening 8. The fan case 21 is formed with screw fixing portions 29a, 29b, and 29c for fixing the cooling module 20 to the circuit board 10 with screws. The screw fixing portions 29a, 29b, and 29c are fixed to the circuit board 10 via the bosses 31a, 31b, and 31c and the screws 33a, 33b, and 33c.
[0020]
The heat receiving plate 22 is formed in a flat leaf spring shape and has spring characteristics. Therefore, the heat receiving plate 22 functions as a cantilever leaf spring in which the vicinity of the boundary with the fan case 21 is supported by the fan case 21. The heat receiving plate 22 is supported by the circuit board 10 while being thermally connected to the heat from the CPU 16. Fixing portions 27 and 28 are integrally formed at the end portion of the heat receiving plate 22 to be fixed to the circuit board 10. Since the fixing portions 27 and 28 are also formed with the same thickness as the heat receiving plate 22, they have a leaf spring characteristic. Screw holes 30 a and 30 b for screw fixing to the circuit board 10 are formed in the fixing portions 27 and 28. The fixing portions 27 and 28 are fixed to the circuit board 10 with screws 35a and 35b and bosses 32a and 32b.
[0021]
FIG. 4 is a view showing a cross section taken along the line AA ′ in FIG. 3. The fan 26 and the rotor 25 are rotationally driven by a motor 25 a supported by the fan case 21. A heat receiving portion 22 a that protrudes slightly from the heat receiving plate 22 is integrally formed at substantially the center of the back surface of the heat receiving plate 22.
[0022]
As shown in FIG. 4, heat from the element 18 of the CPU 16 mounted on the circuit board 10 via the CPU socket 12 is received by a heat receiving portion 22a of the heat receiving plate 22 via a heat transfer member 40 such as a heat transfer sheet or heat transfer grease. Heat is transferred to. The heat transferred to the heat receiving plate 22 is transferred to the fan case 21, cooled by the air flowing in from the suction port 23 by the rotation of the fan 26, and discharged laterally from the discharge port 24. The air discharged from the discharge port 24 is discharged outside through the opening 8 on the side surface of the main body.
[0023]
FIG. 5 is a cross-sectional view of the cooling module according to the first embodiment. As shown in FIG. 5, the heat receiving plate 22 is formed integrally with the fan case 21, and the heat receiving plate 22 functions as a leaf spring at a boundary 22 b with the fan case 21. As shown in the figure, the heat receiving plate 22 can be displaced up and down.
[0024]
FIG. 6 is a view showing a cross section taken along the line AA ′ in FIG. 5 when the cooling module is mounted in accordance with the mounting height dimension of the CPU. As shown in FIG. 6, even when the mounting height of the CPU socket 12 is distorted and the mounting height of the CPU 16 varies, the heat receiving plate 22 has the heat receiving portion 22a near the heat receiving portion 22a upward depending on the mounting height of the CPU 16. It comes into close contact with the CPU 16 in a raised state, that is, in a state displaced in the direction of the arrow in FIG. Therefore, since excessive stress is not applied to the CPU 16 and the CPU socket 12, it is possible to suppress damage to the CPU 16 and the CPU socket 12 itself, or the pins 19 and the solder balls 15 as much as possible.
[0025]
FIG. 7 is a perspective view of the cooling module according to the second embodiment. FIG. 8 is a view showing a cross section taken along line BB ′ in FIG. Parts having the same structure as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.
[0026]
Extending portions 41 a and 41 b are integrally formed from the heat receiving plate 22. Since the extending portions 41a and 41b are formed to have the same thickness as the heat receiving plate 22, they also function as leaf springs. Further, leg portions 41c and 41d extending downward from the extending portions 41a and 41b are integrally formed, and fixing portions 41e and 41f are formed from the leg portions 41c and 41d. As shown in FIG. 8, screw holes 42a and 42b for screw fixing are formed in the fixing portions 41e and 41f, and are fixed to the circuit board 10 by screws 35a and 35b.
[0027]
FIG. 9 is a cross-sectional view of the cooling module according to the second embodiment. As in the first embodiment, the heat receiving plate 22 is formed integrally with the fan case 21, and the heat receiving plate 22 functions as a leaf spring with a boundary 22 b with the fan case 21 as a boundary. As shown in the figure, the heat receiving plate 22 can be displaced up and down.
[0028]
FIG. 10 is a view showing a cross section taken along line BB ′ in FIG. 7 when the cooling module is mounted according to the mounting height dimension of the CPU. As shown in FIG. 10, even when the mounting height of the CPU socket 12 is distorted and the mounting height of the CPU 16 varies, the heat receiving plate 22 has its heat receiving portion 22a near the heat receiving portion 22a upward depending on the mounting height of the CPU 16. It comes into close contact with the CPU 16 in a raised state. Therefore, since excessive stress is not applied to the CPU 16 and the CPU socket 12, it is possible to suppress damage to the CPU 16 and the CPU socket 12 itself, or the pins 19 and the solder balls 15 as much as possible.
[0029]
In the second embodiment, the fixing portions 42a and 42b can be directly fixed to the circuit board 10, which contributes to a reduction in the number of parts compared to the first embodiment. Furthermore, since the extending portions 41a and 41b and the leg portions 41c and 41d also function as leaf springs, the variation in the mounting height of the CPU 16 is followed to the CPU 16 of the heat receiving plate 22 compared to the first embodiment. Adhesion can be performed efficiently.
The present invention is not limited to the above embodiment as long as it does not depart from the gist of the present invention.
[0030]
【The invention's effect】
According to the invention described in detail above, even if there is an error in the mounting dimensions of the electronic component or electronic component, it can be cooled well without damaging the electronic component, improving assemblability, reducing the number of components, Cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view of a computer.
FIG. 2 is an exploded perspective view of a CPU.
FIG. 3 is a perspective view of a cooling module according to the first embodiment.
4 is a view showing a cross section taken along the line AA ′ in FIG. 3;
FIG. 5 is a cross-sectional view of the cooling module according to the first embodiment.
6 is a cross-sectional view taken along line AA ′ in FIG. 3 when a cooling module is mounted according to the mounting height dimension of the CPU.
FIG. 7 is a perspective view of a cooling module according to a second embodiment.
FIG. 8 is a view showing a cross section taken along line BB ′ in FIG. 7;
FIG. 9 is a cross-sectional view of a cooling module according to a second embodiment.
10 is a view showing a cross section taken along line BB ′ in FIG. 7 when a cooling module is mounted according to the mounting height dimension of the CPU.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Computer, 2 ... Upper case, 3 ... Lower case, 4 ... Main body, 5 ... Keyboard, 6 ... Hinge part, 7 ... Display part, 8 ... Opening, 10 ... Circuit board, 11 ... Electrode Pad, 12 ... CPU socket, 13, 17 ... base, 14 ... hole, 15 ... solder ball, 16 ... CPU, 18 ... element, 19 ... electrode pin, 21 ... Cooling module, 21 ... Fan case, 22 ... Heat receiving plate, 22a ... Heat receiving part, 22b ... Border, 23 ... Suction port, 24 ... Discharge port, 25. .. Rotor, 26... Fan, 29a, 29b, 29c... Screw fixing portion, 31a, 31b, 31c, 32a, 32b... Boss, 33a, 33b, 33c, 35a, b. 40 ... Heat transfer member, 41a, 41b ... Extension part, 41c, 4 d · · · legs, 41e, 41f ··· fixing portion, 42a, 42b ··· screw hole

Claims (7)

The body,
A circuit board built in the main body and mounted with electronic components that generate heat during operation;
A fan case mounted on the circuit board and supporting the fan unit, and supported by the fan case and thermally connected to the electronic component to transfer heat from the electronic component and to form a leaf spring. A cooling module comprising a heat receiving plate;
An electronic apparatus comprising:   The body,
  A circuit board built in the main body and mounted with electronic components that generate heat during operation;
  A fan case mounted on the circuit board and supporting the fan unit, and supported by the fan case and thermally connected to the electronic component to transfer heat from the electronic component and to form a leaf spring. A cooling module comprising: a heat receiving plate; an inlet provided on an upper surface of the fan case for introducing air; and a discharge port provided on a side surface of the fan case for discharging the introduced air;
  An electronic apparatus comprising:   The body,
  A circuit board built in the main body and mounted with electronic components that generate heat during operation;
  A fan case mounted on the circuit board and supporting the fan unit, and formed integrally with the fan case, thermally connected to the electronic component to transfer heat from the electronic component, and in a leaf spring shape A cooling module comprising a formed heat receiving plate;
  An electronic apparatus comprising:   The electronic apparatus according to claim 1, wherein the heat receiving plate has a fixing portion, and the fixing portion is fixed to the circuit board.   4. The electron according to claim 1, wherein the fan case has an inflow port through which air flows in on an upper surface, and a discharge port through which air that has flowed in from the inflow port is discharged is formed on a side surface. machine.   The electronic apparatus according to claim 2, wherein the main body has an opening on a side surface, and the discharge port faces the opening.   The electronic device according to claim 6, wherein the electronic component and the heat receiving plate are thermally connected via a heat transfer member.

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