JP2002111260A - Heat dissipation structure of electronic equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To ensure that heat generated in an electronic component mounted on a printed circuit board can be radiated without using a radiator as a separate component, thereby reducing component costs and simplifying assembly work. To achieve. In a wiring pattern formed on an upper surface of a printed circuit board, a heat radiation area having an enlarged area is formed at a portion connecting a GND terminal of an IC to an earth line. A part of the heat radiation area 22 is used as a land part 23 for connection of the GND terminal 31a of the IC 3, and a part of the heat radiation area 22 is connected to the GND terminal 31 of the IC 3.
a is fixed by the solder 6 while maintaining the electrical connection state. The heat radiation area 22 including the land portion 23 has an area larger than other portions of the wiring pattern 2 and is open to the upper surface. Therefore, the heat generated in the IC 3 is transferred from the GND terminal 31 a to the heat radiation area 22.
After being conducted to the outside, the heat is radiated to the outside in the heat radiation area 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device in which electronic components having a large amount of heat, such as semiconductor components such as ICs, LSIs, and power transistors, are mounted on a printed circuit board on which a wiring pattern is formed. The present invention relates to a heat radiation structure of an electronic device that radiates heat generated in the electronic device to the outside.

[0002]

2. Description of the Related Art In an electronic device in which an electronic component having a large amount of heat, such as a semiconductor component, is mounted on a printed circuit board on which a wiring pattern is formed, heat generated in the electronic component is externally transmitted in order to stably operate each electronic component. Need to dissipate heat. On the other hand, if the heat generated in the electronic component is radiated to the outside by a radiator in contact with the electronic component,
In order to maintain the contact state between the electronic components and the radiator, it is necessary to apply grease, and the radiator must be fixed by soldering while making contact with the electronic components. It becomes complicated.

Japanese Patent Application Laid-Open No. H11-45966 discloses a conventional heat dissipation structure for electronic equipment.
0, an electronic component 103 such as an IC which is a heating element.
A configuration is disclosed in which a radiator 104 is connected to and attached to a part of a wiring pattern 102 on a printed board 101 on which is mounted. With this configuration, heat generated in the electronic component 103 is radiated from the radiator 104 via the wiring pattern 102. The radiator 104 is mounted on the printed circuit board 101.
Since it is mounted alone on the top, there is no need to directly contact the electronic component 103. Therefore, there is no need to apply grease to maintain the contact state between the electronic component 103 and the radiator 104, and it is not necessary to fix the radiator 104 by soldering while making contact with the electronic component 103. The assembling work of the device 103 can be facilitated.

[0004]

However, the structure disclosed in Japanese Patent Application Laid-Open No. H11-45966 is the same as that of the conventional electronic equipment in that a radiator is mounted on a printed circuit board. Since a radiator, which is a component, is indispensable, and a work for attaching the radiator to a printed circuit board is also required, there has been a problem that it has been impossible to reduce the cost of parts and to simplify the assembly work.

SUMMARY OF THE INVENTION It is an object of the present invention to ensure that heat generated in an electronic component mounted on a printed circuit board can be radiated without using a radiator, which is another component, thereby reducing the cost of parts and assembling work. It is an object of the present invention to provide a heat dissipation structure for an electronic device which can simplify the above.

[0006]

The present invention has the following arrangement as means for solving the above-mentioned problems.

(1) In an electronic device configured by mounting electronic components on a printed circuit board on which a wiring pattern is formed,
The heat generated in the electronic component is radiated from the wiring pattern.

In this configuration, the heat generated in the electronic components connected to the wiring pattern on the printed board is radiated from the wiring pattern. Therefore, a radiator to be attached to the printed circuit board is not required, and an operation of attaching the radiator to the printed circuit board in assembling the electronic device is omitted.

(2) The wiring pattern is characterized in that the wiring pattern partially includes a heat radiation area having an increased surface area.

In this configuration, the electronic component is connected to the wiring pattern of the printed circuit board whose surface area is enlarged in the heat radiation area. Therefore, the heat generated in the electronic component is efficiently radiated from the heat radiation area after conducting to the wiring pattern.

(3) The heat radiation area is formed at a portion of the wiring pattern connected to the GND terminal of the electronic component.

In this configuration, the GND terminal of the electronic component is connected to the heat radiation area of the wiring pattern. Therefore, the heat generated in the electronic component is conducted from the GND terminal to the heat radiation area of the wiring pattern to be dissipated more efficiently, and the electronic component is not electrically affected by the connection with the heat radiation area.

(4) In an electronic device configured by mounting electronic components on a printed circuit board on which a wiring pattern is formed,
A heat conductive member is disposed between a portion of the wiring pattern connected to the electronic component and the heat radiating member.

In this configuration, the electronic component is connected to the heat dissipating member via the heat conducting member and the heat conducting member. Therefore, heat generated in the electronic component is conducted to the heat radiating member via the wiring pattern and the heat conducting member, and is efficiently radiated by the heat radiating member.

(5) In the configuration of (4), a jumper wire or a heat conductive harness that contacts the heat radiating member can be used as the heat conductive member.

According to this structure, the heat generated in the electronic component and then transmitted to the wiring pattern is efficiently transmitted to the heat radiating member via the jumper wire or the heat conductive harness, so that the heat generated in the electronic component is radiated. The heat can be efficiently radiated to the outside from the member, and the malfunction, deformation, noise, and the like of the electronic component due to the high temperature can be reliably prevented.

(6) In the configuration of (4), the heat conductive member can be connected to a portion of the wiring pattern connected to the GND terminal of the electronic component.

According to this structure, the heat generated in the electronic component can be conducted to the heat conducting member from the GND terminal via the wiring pattern in the shortest distance, and the heat generated in the electronic component can be more efficiently conducted. To conduct,
The heat generated in the electronic component can be more efficiently radiated to the outside from the heat radiating member, and the operation failure, deformation, noise, and the like of the electronic component due to a high temperature can be more reliably prevented.

(7) In the configuration of (4), a heat conductive frame of the apparatus main body can be used as the heat radiating member.

According to this structure, it is necessary to provide a single component as a heat radiating member by radiating the heat generated in the electronic component to the wiring pattern and the heat conductive member to the outside from the heat conductive frame of the apparatus main body. Without
An increase in cost due to an increase in the number of parts and an increase in the complexity of the assembling work can be prevented.

(8) The printed circuit board is a multilayer printed circuit board formed by laminating a plurality of printed circuit boards, and is provided with a heat conductor for connecting a connection portion of the wiring pattern of each printed circuit board to a GND terminal of an electronic component. It is characterized by the following.

In this configuration, portions of the wiring pattern formed on each printed circuit board constituting the multilayer printed circuit board, which are connected to the GND terminal of the electronic component, are connected by a heat conductor. Therefore, the heat generated in the electronic components mounted on each printed circuit board is radiated from the common heat radiating member via the heat conductor disposed between the printed circuit boards.

[0023]

FIG. 1 is a plan view of a printed circuit board of an electronic device to which a heat dissipation structure according to a first embodiment of the present invention is applied. On the upper surface of the printed circuit board 1, a wiring pattern 2 is formed of a conductive material, and an IC 3, which is an electronic component that generates high heat, is mounted together with other electronic components 4 such as a capacitor and a resistor. Wiring pattern 2
A plurality of terminals 31 extending from the IC 3 on the printed circuit board 1
Of these, a predetermined terminal is formed so as to be electrically connected to another terminal or another electronic component 4.

More specifically, on the printed circuit board 1, the upper surface of the wiring pattern 2 is covered with a resist film except for a part, and the portion of the wiring pattern 2 whose upper surface is not covered with the resist film is a terminal of the IC 3. 31
The lands used to connect with are. That is, the land portion of the wiring pattern 2 is mounted on an IC mounted on the upper surface thereof.
3 terminal 31 is soldered.

The wiring pattern 2 includes an earth line 21 formed over the entire periphery of the upper surface of the printed circuit board 1, and the earth line 21 and the GND of the IC 3.
Heat radiating area 2 having a predetermined area disposed between terminals 31a
2 inclusive.

FIG. 2 is a side sectional view of a portion of the printed circuit board where a heat radiation area is formed. A resist film 5 is formed on a portion of the upper surface of the printed circuit board 1 where the IC 3 is mounted, and the IC 3 is mounted on the upper surface of the resist film 5. On the other hand, a resist film is not formed on the upper surface of the heat radiation area 22 connecting the GND terminal 31a of the IC 3 and the ground line 21 in the wiring pattern 2, and a part of the heat radiation area 22 is
It is used to connect the GND terminal 31a of C3. That is, the GND terminal 31 a of the IC 3 is fixed to a part of the heat radiation area 22 by the solder 6 while maintaining the electrical connection state. The resist film 5 prevents the solder from flowing between the IC 3 and the upper surface of the printed circuit board 1.

The heat radiating area 22 including the land 23 to which the GND terminal 31a of the IC 3 is connected has a larger area than other parts of the wiring pattern 2, and
Open to the top. Therefore, the heat generated in the IC 3 is conducted from the GND terminal 31a to the heat radiation area 22 and then radiated to the outside in the heat radiation area 22, and the printed circuit board 1 on which the electronic component is mounted becomes high in temperature. Problems such as deformation of the substrate 1 and generation of noise can be reliably prevented.
For this reason, there is no need to separately provide a radiator for radiating the heat generated in the IC 3, and the cost can be reduced and the assembling operation can be simplified.

The area of the heat radiating area 22 can be enlarged or reduced according to the amount of heat generated in the IC 3.

Further, as shown in this embodiment, when the earth line 21 is formed continuously with the heat radiating area 22, a part of the heat conducted to the heat radiating area 22 is radiated from the earth line 21, A heat radiation area including the ground line 21 can be provided.

FIG. 3 is a plan view of a printed circuit board of an electronic device to which a heat radiation structure according to a second embodiment of the present invention is applied. FIG. 4 is a side sectional view of a main part of the printed circuit board. Printed circuit board 10 according to this embodiment
In this embodiment, a jumper wire 7 is provided in place of the heat radiation area 22 of the printed circuit board 1 according to the first embodiment shown in FIGS. That is, the printed circuit board 10 is connected to the end portion of the jumper wire 7 made of a high heat conductive material whose middle portion is in contact with the heat conductive frame 8 of the electronic device main body.
3 is connected to the GND terminal 31a of the IC 3 via the IC terminal 3. In this example, both ends of the jumper wire 7 are connected to the GND terminals 31a of the two ICs 3 mounted on the printed circuit board 10, respectively.

With this configuration, the heat generated in the IC 3 is transmitted to the heat conductive frame 8 via the GND terminal 31a, the land 23, and the jumper wire 7 in this order, and is radiated from the jumper wire 7 during this time. Is diffused to the heat conductive frame 8 and radiated to the outside. Therefore,
It is possible to reliably prevent malfunctions of the electronic components, deformation of the printed circuit board 1, and generation of noise due to the high temperature of the printed circuit board 1 on which the electronic components are mounted due to the heat generated in the IC 3. Therefore, IC
It is not necessary to separately provide a radiator for radiating the heat generated in 3, so that cost reduction and simplification of assembly work can be realized.

When the heat generated in the IC 3 can be reliably radiated from the jumper wire 7, it is not necessary to bring the jumper wire 7 into contact with the heat conductive frame 8.

As shown in FIGS. 5 and 6, one end is connected to the GND of the IC 3 via the land 23 of the wiring pattern 2.
Jumper wire 7 of a high thermal conductive material connected to terminal 31a
May be connected to fixing pins 9 for fixing the printed circuit board 10 to the electronic device body. In this case, in order to increase the amount of heat released by the jumper wire 7, the other end of the jumper wire 7 is connected to one end of the jumper wire 7 of the plurality of fixing pins 9 provided on the printed circuit board 10.
It is desirable to connect to the fixed pin 9 farthest from the GND terminal 31a of C3. Also in this case, the intermediate portion of the jumper wire 7 can be selectively brought into contact with the heat conductive frame 8 according to the heat generation amount of the IC 3 and the heat release amount of the jumper wire 7.

Further, as shown in FIG. 7, in a multilayer printed circuit board on which a plurality of printed circuit boards 10 are stacked, the GND
The lands 23 of the wiring pattern 2 to which the terminals 31a are connected are connected by the thermal conductor 11, and the lands 23 of the wiring pattern 2 to which the GND terminals 31a of the IC 3 are connected and the fixing pins 9 are connected on the lower surface of the lowermost printed circuit board 10. And a jumper wire 7 can be arranged between the two. With this configuration, heat generated in the IC 3 mounted on each printed circuit board 10 is transferred to the land portion 2 of the lowermost printed circuit board 10 via the GND terminal 31 a, the land portion 23 and the thermal conductor 11.
3 and can radiate heat from the jumper wire 7.
Also in this case, the intermediate portion of the jumper wire 7 can be selectively brought into contact with the heat conductive frame 8 according to the heat generation amount of the IC 3 and the heat release amount of the jumper wire 7.

In addition, as shown in FIG. 8, the harness 12 penetrating the printed circuit board 10 and having one end in contact with the land 23 of the wiring pattern 2 to which the GND terminal 31a of the IC 3 is connected, and the other end being an electronic The frame 8 itself of the device body,
Alternatively, it can be arranged in contact with the heat conductive sheet metal 13 attached to the frame 8. With this configuration, I
The heat generated in C3 is conducted to the frame 8 or the heat conductive sheet metal 13 via the GND terminal 31a, the land portion 23, and the harness 12, and the frame 8 or the heat conductive sheet metal 13
Can be dissipated.

[0036]

According to the present invention, the following effects can be obtained.

(1) By dissipating the heat generated in the electronic components connected to the wiring pattern on the printed circuit board from the wiring pattern, it is possible to eliminate the need for a radiator attached to the printed circuit board, The work of attaching to the printed circuit board can be omitted. Thus, the cost can be reduced and the efficiency of the assembling work can be improved.

(2) By connecting an electronic component to a wiring pattern having an increased surface area in a heat radiation area on a printed circuit board, heat generated in the electronic component is efficiently radiated from the heat radiation area after being conducted to the wiring pattern. Can be.

(3) By connecting the GND terminal of the electronic component to the heat radiating area of the wiring pattern, the heat generated in the electronic component can be conducted from the GND terminal to the heat radiating area of the wiring pattern to radiate heat more efficiently. In addition to the above, the connection with the heat radiation area does not affect the electronic components electrically.

(4) By connecting the electronic component to the heat dissipating member via the heat conducting member and the heat conducting member, heat generated in the electronic component is conducted to the heat dissipating member via the wiring pattern and the heat conducting member. The heat can be efficiently dissipated by the heat dissipating member.

(5) The connection parts of the wiring patterns formed on each printed circuit board constituting the multilayer printed circuit board with the GND terminals of the electronic components are connected to each other by a thermal conductor, thereby being mounted on each printed circuit board. The heat generated in the electronic component can be radiated from a common heat radiating member via a heat conductor disposed between the printed circuit boards.

[Brief description of the drawings]

FIG. 1 is a plan view of a printed circuit board of an electronic device to which a heat dissipation structure according to a first embodiment of the present invention has been applied.

FIG. 2 is a side sectional view of a portion of the printed circuit board where a heat radiation area is formed.

FIG. 3 is a plan view showing a printed circuit board of an electronic device to which a heat dissipation structure according to a second embodiment of the present invention is applied.

FIG. 4 is a side view showing a configuration of a main part of the printed circuit board.

FIG. 5 is a plan view showing a printed circuit board of an electronic device to which a heat dissipation structure according to a third embodiment of the present invention is applied.

FIG. 6 is a side view showing a configuration of a main part of the printed circuit board.

FIG. 7 is a side view showing a printed circuit board of an electronic device to which a heat dissipation structure according to a fourth embodiment of the present invention is applied.

FIG. 8 is a side view showing a printed circuit board of an electronic device to which a heat dissipation structure according to a fifth embodiment of the present invention is applied.

FIG. 9 is a plan view of a printed circuit board having a conventional heat dissipation structure.

FIG. 10 is a side sectional view of a printed circuit board having the conventional heat dissipation structure.

[Explanation of symbols]

 1,10-Printed circuit board 2-Wiring pattern 3-IC 4-Electronic component 5-Resist film 6-Solder 7-Jump line 8-Frame 9-Fixation pin 11-Thermal conductor 12-Harness 13-Heat conductive sheet metal 22 -Heat dissipation area 23-Land part 31-GND terminal

Claims (5)

[Claims] 1. A heat dissipation structure for an electronic device, wherein heat generated in the electronic component is radiated from the wiring pattern in an electronic device configured by mounting the electronic component on a printed circuit board on which a wiring pattern is formed. 2. The heat dissipation structure for an electronic device according to claim 1, wherein the wiring pattern includes a heat dissipation area having an increased surface area. 3. The heat dissipating structure for an electronic device according to claim 2, wherein the heat dissipating area is formed at a portion of the wiring pattern connected to a GND terminal of the electronic component. 4. An electronic device comprising an electronic component mounted on a printed circuit board having a wiring pattern formed thereon, wherein a heat conducting member is arranged between a portion of the wiring pattern connected to the electronic component and a heat radiating member. Heat dissipation structure of electronic equipment characterized by the following. 5. The printed circuit board is a multi-layer printed circuit board formed by laminating a plurality of printed circuit boards, and further includes a heat conductor for connecting a connection portion of a wiring pattern of each printed circuit board to a GND terminal of an electronic component. The heat dissipation structure for an electronic device according to claim 4, wherein: