JP2007294619A - Heat dissipation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat dissipation structure capable of reducing the influence of heat generated by a component incorporated in equipment on a case etc., by conducting the heat generated by the component. <P>SOLUTION: A flexible wiring board 100 is mounted with the circuit component (heat generating component) having large heat value. A ground pattern 15 includes a wiring part 15a connected to the component 500. Then the wiring part 15a is connected to a region 15b formed in a right-side region of the flexible wiring board 100 to a wide area. The heat generated by the component 500 is conducted beyond a base 12 to the wiring part 15a and then conducted to the region 15b through the wiring part 15a. Then the heat is dissipated to outside the flexible wiring board 100 through a second cover lay 13. A region 15b is formed over a wide range on the flexible wiring board 100, so the heat dissipation effect is large as compared with a case wherein the region 15b is not provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat dissipation structure for releasing heat generated by components incorporated in a device such as a mobile phone.

  With the progress of miniaturization and thinning of cellular phones, the mounting density of circuit components and the like is increasing inside the housing. As a result, it is difficult to release the heat generated from the circuit components and the like inside the casing, and the casing may be heated. If the casing is heated, the user of the mobile phone may feel uncomfortable.

  As a heat dissipation structure for dissipating heat from a circuit component that generates heat in a mobile phone (hereinafter referred to as a heat generation component), a planar ground pattern is provided on a printed wiring board, and heat from the heat generation component is dissipated from the ground pattern. (For example, refer to Patent Document 1). In Patent Document 1, it is supposed that heat from a heat-generating component can be radiated by thinning the mobile phone by such a heat radiating structure of the mobile phone.

JP 2003-298454 A (paragraphs 0012-0013, FIG. 9)

  However, in the heat dissipation structure described in Patent Document 1, a recessed portion is provided in the printed wiring board at a lower portion of a display unit such as an LCD module, and a ground pattern is provided in the recessed portion. In the printed wiring board, circuit components are mounted in regions other than the recesses. Then, the thickness of the display unit installation portion is not increased by the concave portion, and the ground pattern contributes to heat dissipation, but the mounting area is narrowed in the printed wiring board. This is because the display unit enters the concave portion of the printed wiring board, and circuit components cannot be mounted on that portion. Since the circuit component mounting area is limited, high-density mounting is restricted. As a result, downsizing of the mobile phone is hindered.

  Therefore, the present invention can release the heat generated by the components incorporated in the device without reducing the size reduction of the device and reduce the influence of the heat generated by the components on the housing or the like. An object of the present invention is to provide a heat dissipation structure that can be used.

  The heat dissipating structure according to the present invention has a layer (for example, a layer between the first cover lay 11 and the base 12) provided with a signal wiring pattern on a wiring substrate (for example, the flexible wiring substrate 100) on which a heat generating component is mounted. A large area (for example, the region 15b) of a specific conductive pattern (for example, a ground pattern) is provided in a layer different from (for example, a layer between the base 12 and the second coverlay 13). Features. The large area means that, for example, the conduction pattern transmits an electrical signal (including a signal for transmitting information such as a control signal, a voltage signal from a power supply, and a ground (GND) signal). The area is larger than the required area.

  In another aspect of the heat dissipation structure according to the present invention, the wiring board (for example, the flexible wiring board 202) electrically connects the first mounting area on which the heat generating component is mounted, and the first mounting area and the other area. A connection region provided with a signal wiring pattern, and the connection region includes a layer provided with the signal wiring pattern (for example, a layer between the first cover lay 51 and the base 52) and another layer (for example, , A layer between the base 52 and the second cover lay 53), and a large area region (for example, a ground pattern) connected to a specific conduction pattern (for example, a ground pattern) in the first mounting region. , A region 55b) is provided.

  According to still another aspect of the heat dissipation structure of the present invention, a wiring board includes a first mounting region, a connection region provided with a signal wiring pattern for electrically connecting the first mounting region and another region, and a heat generating component. And a second mounting region connected to the first mounting region, and the connection region is a layer provided with a signal wiring pattern (for example, a layer between the first coverlay 51 and the base 52). And another layer (for example, a layer between the base 52 and the second cover lay 53), and connected to a specific conduction pattern (for example, a ground pattern) in the first mounting region on the other layer. A large area area (for example, the area 55b) is provided, and heat conduction means (for example, the ground pattern 29) for conducting the heat generated by the heat generating component to the specific conduction pattern of the first mounting area is provided. Features.

  The heat conduction means is, for example, a specific conduction pattern (for example, a ground pattern 29) in the second mounting region. In addition, it is preferable that the width | variety of a specific conduction pattern is more than predetermined | prescribed magnitude | size (for example, 3 times the width | variety required for a conduction pattern to transmit an electrical signal).

  The second mounting area includes a layer provided with a signal wiring pattern (for example, a layer between the first cover lay 31 and the base 32) and another layer (for example, the base 32 and the second cover lay 33). The heat conduction means is a conduction pattern formed on another layer and connected to a specific conduction pattern in the first mounting region (for example, a ground pattern 35). May be.

  The heat conducting means is, for example, a metal member (for example, a metal plate 60) bonded to the first mounting region and the second mounting region.

  In the heat dissipation structure, the second mounting area is bent with respect to the first mounting area at the bent portion, and the heat conducting means is a first metal member (for example, the metal plate 61) attached to the first mounting area and the second mounting area. The structure may include a second metal member (for example, metal plate 62) attached to the mounting region, and the first metal member and the second metal member may be attached to each other.

  In another aspect of the heat dissipation structure according to the present invention, the first wiring board (for example, the flexible wiring board 70) on which the heat-generating component is mounted and the wide area region of the specific conduction pattern (for example, the grounding pattern) are provided. 2 wiring boards (for example, flexible wiring board 80), and having heat conduction means (for example, metal plates 61 and 62) for conducting heat generated by the heat generating component to a large area.

  In the heat dissipation structure, the heat conducting means includes a first metal member (for example, metal plate 61) affixed to the first wiring board and a second metal member (for example, metal plate 62) affixed to the second wiring board. In addition, a structure in which the first metal member and the second metal member are bonded together may be used.

  According to the present invention, heat from the heat generating component is dissipated from a wide area formed on the wiring board, so that heat generated by the component incorporated in the device is released and the heat generated by the component is transferred to the housing or the like. Can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
1A and 1B are a plan view and a sectional view showing a first embodiment of a heat dissipation structure according to the present invention. The printed wiring board (printed wiring board) shown in FIG. 1 is a flexible wiring board 100, and one circuit component 500 is mounted as an example.

  FIG. 1A is a plan view when the upper surface (mounting surface of the circuit component 500) of the flexible wiring substrate 100 is viewed, and FIG. 1B is a view of the lower surface (back surface) of the flexible wiring substrate 100. FIG. FIG. 1C is a cross-sectional view taken along the line CC of FIG. 1A.

  As shown in FIG. 1 (C), the flexible wiring board 100 is a double-sided flexible board. From the top, the first cover lay 11, a wiring pattern 14 as a signal line made of metal, a base (base material) 12, and a metal In this structure, the ground pattern 15 and the second coverlay 13 are laminated. The metal of the material of the wiring pattern 14 and the ground pattern 15 is, for example, copper, and specifically, the pattern is formed as a copper foil. The material of the first coverlay 11, the base 12, and the second coverlay 13 is, for example, polyimide.

  Although FIG. 1 shows an example in which one component 500 is mounted on the flexible wiring board 100, a plurality of components may be mounted on the flexible wiring board 100. The component 500 is a circuit component (heat generating component) that generates a large amount of heat such as a light emitting element such as an LED or an IC that consumes a large amount of current.

  The ground pattern 15 includes a wiring portion 15 a connected to the component 500. As shown in FIG. 1B, the wiring portion 15a is connected to a region 15b formed over a large area in the region on the right side of the flexible wiring substrate 100. In the example shown in FIG. 1B, it is formed in almost the entire region (or the entire region may be entirely) in the right region. Actually, the wiring portion 15 a and the region 15 b are formed at the same time when the flexible wiring substrate 100 is manufactured. Further, the wiring portion 15a is preferably as wide as possible from the viewpoint of heat conduction.

  In addition, as shown in FIG. 1C, a second coverlay 13 is formed at the bottom of the flexible wiring board 100, but the second coverlay 13 is generally transparent or substantially transparent. . Accordingly, when the lower surface of the flexible wiring board 100 is viewed, the ground pattern 15 is visually recognized as shown in FIG. The wiring portion 15a is preferably connected to the component 500, but may not be connected to the component 500. When there is no ground pattern 15 connected to the component 500, the wiring portion 15a passing through the vicinity of the component 500 is connected to the wide area region 15b.

  In the flexible wiring board 100 having the heat dissipation structure shown in FIG. 1, the heat generated by the component 500 is conducted to the wiring portion 15a through the base 12 and to the region 15b through the wiring portion 15a. Then, heat is radiated to the outside of the flexible wiring board 100 through the second cover lay 13. As shown in FIG. 1B, the area of the metal region 15b is large. That is, in the flexible wiring board 100, the region 15b is formed over a wide range. In other words, the heat dissipation area is wide. Therefore, the heat dissipation effect is greater than when the region 15b is not provided.

  Further, as shown in FIG. 2, when the second cover lay 13 is connected to the metal plate 17, the heat dissipation effect can be further enhanced.

Embodiment 2. FIG.
FIG. 3 is a plan view and a sectional view showing a second embodiment of the heat dissipation structure according to the present invention. 3A is a plan view when the upper surface of the flexible wiring board 202 (mounting surface of the component 500) is viewed, and FIG. 3B is a plan view when the lower surface of the flexible wiring board 202 is viewed. It is. More specifically, FIG. 4 is a view of a state in which the state shown in FIG. FIG. 3C is a cross-sectional view taken along the line CC of FIG. 3A. However, the sectional view is shown enlarged with respect to the plan view.

  The flexible wiring board 202 illustrated in FIG. 3 includes a first mounting area 20 and another mounting area (referred to as a third mounting area) 40. One or more circuit components are mounted in the first mounting area 20. One or more circuit components are mounted in the third mounting region 40. FIG. 3A shows a state where the component 500 with a large amount of heat generation is mounted in the first mounting region 20. The first mounting area 20 is connected to the third mounting area 40 by a signal wiring pattern 90 including a plurality of signal lines. The signal wiring pattern 90 includes a power line (power pattern) and a ground line (ground pattern).

  In the flexible wiring board 202, a connection region 50 is provided between the first mounting region 20 and the third mounting region 40. The connection area 50 is assumed to be an area from the lower side of the first mounting area 20 shown in FIG. 3A to the right side of the third mounting area 40 (left side in FIG. 3B). The first mounting area 20, the third mounting area 40, and the connection area 50 are each part of one flexible wiring board 202. Further, at least a portion of the connection region 50 is formed as a double-sided flexible substrate as shown in FIG. That is, the first cover lay 51, the signal wiring pattern 90 as a metal signal line, the base (base material) 52, the metal ground pattern 55, and the second cover lay 53 are laminated from the top. . The metal of the material of the signal wiring pattern 90 and the ground pattern 55 is, for example, copper, and specifically, the pattern is formed as a copper foil. The material of the first coverlay 51, the base 52, and the second coverlay 53 is, for example, polyimide.

  As shown in FIG. 3B, the ground pattern 55 corresponds to a connection portion with the third mounting region 40 from a portion P corresponding to the connection portion with the first mounting region 20 in the connection region 50. It is formed in almost the entire region (may be entirely the entire region) up to the point Q. In the example illustrated in FIG. 3, the portion Q before the portion Q corresponding to the connection portion with the third mounting region 40 is more illustrated than the bent portion R provided between the connection region 50 and the third mounting region 40. 3 (B) is an upper portion. The ground pattern 55 includes a wiring portion 55a and a large area 55b.

  The width of the wiring portion 55a is slightly wider than the width of the signal wiring pattern 90, but the width of the region 55b is significantly wider than the width of the wiring portion 55a. The width of the region 55b is, for example, about three times the width of the wiring portion 55a, but is determined in consideration of spatial restrictions when the flexible wiring board 202 is accommodated in a housing or the like, required heat dissipation efficiency, and the like.

  The heat generated by the component 500 is conducted from the first mounting region 20 to the wiring portion 55a. Specifically, conduction is performed from a ground pattern (not shown) formed in the first mounting region 20 to the wiring portion 55 a in the connection region 50. The wiring portion 55a is a part of the ground pattern and is connected to the ground pattern formed in the first mounting region 20. Further, heat is conducted from the wiring portion 55a to the region 55b. Then, heat is radiated from the region 55b. As shown in FIG. 3B, in the connection region 50, the area of the metal region 55b is large. That is, in the flexible wiring board 202, the region 55b is formed over a wide range. In other words, the heat dissipation area is wide. Therefore, the heat radiation effect is greater than when the region 55b is not provided.

  When the present invention is not applied, it is not necessary to form the connection region 50 as a double-sided flexible substrate, and the width of the connection region 50 is slightly larger than the width of the signal wiring pattern 90 throughout. In contrast, in this embodiment, the connection region 50 is formed as a double-sided flexible substrate, and a wide range of metal regions 55b is provided. That is, the heat dissipation structure is realized using the connection region 50. Therefore, an effective heat dissipation structure can be realized without increasing the size of the flexible wiring board 202. Further, since the shape of the connection region 50 does not give any restriction to the component mounting in the first mounting region 20, mounting of circuit components as in the conventional example (for example, the heat dissipation structure described in Patent Document 1). The area is never narrowed. That is, high-density mounting is not hindered.

  In this embodiment, the ground pattern 55 is formed in a region up to the point Q corresponding to the connection portion with the third mounting region 40, but corresponds to the connection portion with the third mounting region 40. The ground pattern 55 may be extended to the point Q. However, as shown in FIG. 3B, when a structure in which the ground pattern 55 is formed in a region up to a position Q corresponding to the connection portion with the third mounting region 40 is used, An effect is obtained. That is, in the case in which the flexible wiring board 202 is accommodated, for example, even when the first mounting region 20 and the third mounting region 40 are not mounted on the same plane (when there is a step in the mounting location), mounting is easy. Become. Between the end of the region where the ground pattern 55 is formed and the point Q corresponding to the connecting portion, it can be formed as a single-sided flexible substrate on which only the signal wiring pattern 90 is formed, so that the thickness is reduced. This is because the substrate 202 is easily bent.

  The shape of the flexible wiring board 202 shown in FIG. 3 is an example, and the present invention is not limited to the shape shown in FIG. Furthermore, providing the ground pattern 55 in the connection region 50 that connects two regions (the first mounting region 20 and the third mounting region 40) is also an example. A non-connection region may be newly provided, and the ground pattern 55 may be provided there.

Embodiment 3 FIG.
FIG. 4 is a plan view showing a third embodiment of the heat dissipation structure according to the present invention. 4A is a plan view when the upper surface (mounting surface of the component 500) of the flexible wiring board 203 is viewed, and FIG. 4B is a plan view when the lower surface of the flexible wiring board 203 is viewed. It is. More specifically, FIG. 5 is a view of a state in which the state illustrated in FIG. Further, the flexible wiring board 203 of this embodiment has a third mounting area 40 as shown in FIG. 3, for example. FIG. 4 shows the first mounting area 20, the second mounting area 30, and the connection. Only region 50 is shown.

  In this embodiment, the flexible wiring board 203 has a second mounting area 30 in addition to the first mounting area 20. One or a plurality of circuit components are mounted on the first mounting region 20 and the second mounting region 30, respectively. Further, as in the case of the second embodiment, a connection region 50 is provided between the first mounting region 20 and the third mounting region 40 (not shown in FIG. 4). The first mounting area 20, the second mounting area 30, the third mounting area 40, and the connection area 50 are each a part of one flexible wiring board 203. In addition, providing the ground pattern 55 in the connection region 50 that connects the two regions (the first mounting region 20 and the third mounting region 40) is an example. A non-connection region may be newly provided, and the ground pattern 55 may be provided there.

  Further, in this embodiment, it is assumed that the component 500 having a large heat generation amount is mounted in the second mounting region 30.

  As in the case of the second embodiment, in this embodiment, the heat generated by the component 500 is radiated from the region 55b in the ground pattern 55 formed in the connection region 50. However, the second mounting area 30 on which the component 500 is mounted is not directly connected to the connection area 50. In such a case, the heat generated by the component 500 is generated in the first mounting region 20 (specifically, through the ground pattern 29 passing through the portion connecting the first mounting region 20 and the second mounting region 30). Is conducted to the ground pattern formed in the first mounting region 20. Then, as in the case of the second embodiment, conduction is performed from the first mounting region 20 to the region 55b via the wiring portion 55a in the connection region 50. Then, heat is radiated from the region 55b.

  The ground pattern 29 is preferably as wide as possible. The ground pattern 29 is connected to the component 500 in the first mounting area 20. However, when there is no ground pattern 29 connected to the component 500, if there is a ground pattern passing through the vicinity of the component 500, it may be substituted for the ground pattern 29.

  Note that this embodiment is useful when the component 500 that generates heat is mounted in the second mounting region 30 and also when the heat generating component is mounted in the first mounting region 20. This is because the heat from the heat-generating component mounted in the first mounting region 20 is also conducted to the region 55b through the wiring portion 55a in the connection region 50 as in the case of the second embodiment.

Embodiment 4 FIG.
FIG. 5 is a plan view and a sectional view showing a fourth embodiment of the heat dissipation structure according to the present invention. 5A is a plan view when the upper surface of the flexible wiring board 204 (mounting surface of the component 500) is viewed, and FIG. 5B is a plan view when the lower surface of the flexible wiring board 204 is viewed. It is. More specifically, FIG. 6 is a view of a state where the state illustrated in FIG. FIG. 5C is a cross-sectional view taken along the line CC of FIG. 5A. Further, the flexible wiring board 204 of this embodiment has a third mounting area 40 as shown in FIG. 3, for example. FIG. 5 shows the first mounting area 20, the second mounting area 30, and the connection. Only region 50 is shown.

  In the third embodiment, the heat generated by the component 500 is conducted to the first mounting region 20 via the ground pattern 29 that passes through the portion connecting the first mounting region 20 and the second mounting region 30. It was. Then, heat was radiated from the region 55 b in the ground pattern 55 formed in the connection region 50.

  In the present embodiment, at least the second mounting region 30 is formed as a double-sided flexible substrate. In the example shown in FIG. 5, a first cover lay 31, a wiring pattern 34 as a signal line made of metal, a base (base material) 32, a ground pattern 35 made of metal, and a second cover lay 33 are laminated from the top. Structure. The metal of the material of the wiring pattern 34 and the ground pattern 35 is, for example, copper, and specifically, the pattern is formed as a copper foil. The material of the first coverlay 31, the base 32, and the second coverlay 33 is, for example, polyimide.

  In the example shown in FIG. 5, the first mounting region 20 is also formed as a double-sided flexible substrate. That is, from the upper surface, the first cover lay 21, a wiring pattern 24 as a signal line made of metal (for example, copper, specifically formed as a copper foil), a base (base material) 22, a metal (for example, copper, Specifically, it is a structure in which a wiring pattern (GND pattern) 28 and a second coverlay 23 are formed by being formed as a copper foil.

  The ground pattern 35 may be omitted for signal transmission. However, it contributes to heat conduction from the component 500 to the first mounting region 20. Thereafter, as in the case of the third embodiment, heat is conducted from the first mounting region 20 to the region 55b through the wiring portion 55a in the connection region 50, and is radiated from the region 55b.

  Therefore, in this embodiment, the ground pattern 29 (see FIG. 4) connected to the component 500 or the ground pattern passing through the vicinity of the component 500 does not exist, or even if such a ground pattern exists. This is particularly useful when the width of is narrow. That is, when there is no grounding pattern that can be used for heat conduction from the component 500 to the first mounting region 20 as in the third embodiment, the grounding pattern 35 is newly provided, so that the third The same effect as in the embodiment can be obtained.

  Note that this embodiment is useful when the component 500 that generates heat is mounted in the second mounting region 30 and also when the heat generating component is mounted in the first mounting region 20. This is because the heat from the heat-generating component mounted in the first mounting region 20 is also conducted to the region 55b through the wiring portion 55a in the connection region 50, as in the second and third embodiments. In addition, providing the ground pattern 55 in the connection region 50 that connects the two regions (the first mounting region 20 and the third mounting region 40) is an example. A non-connection region may be newly provided, and the ground pattern 55 may be provided there.

Embodiment 5 FIG.
FIG. 6 is a plan view and a sectional view showing a fifth embodiment of a heat dissipation structure according to the present invention. 6A is a plan view when the upper surface of the flexible wiring board 205 (mounting surface of the component 500) is viewed, and FIG. 6B is a plan view when the lower surface of the flexible wiring board 205 is viewed. It is. More specifically, FIG. 7 is a view when the state shown in FIG. 6A is turned over. 6C and 6D are cross-sectional views showing a CC cross section of the structure shown in FIG. 6A. Further, the flexible wiring board 204 of this embodiment has a third mounting area 40 as shown in FIG. 3, for example, but FIG. 6 shows the first mounting area 20, the second mounting area 30, and the connection. Only region 50 is shown.

  6C shows an example in which the first mounting area 20 and the second mounting area 30 are formed as a double-sided flexible substrate, and FIG. 6D shows the first mounting area 20 and the second mounting area. The example in case the area | region 30 is formed as a single-sided flexible substrate is shown. In the example shown in FIG. 6C, the wiring patterns 28 and 38 are ground patterns. However, the wiring patterns 28 and 38 are not newly provided for heat conduction like the ground pattern 35 in the fourth embodiment. It is a pattern used for signal transmission.

  In the fourth embodiment, the heat from the component 500 is conducted to the first mounting region 20 by newly providing the ground pattern 35 in the second mounting region 30. In this embodiment, the metal plate 60 is bonded to the lower surfaces of the first mounting region 20 and the second mounting region 30, and heat from the component 500 is transferred by the metal plate 60 to the first mounting region 20 (specifically, the first mounting region 20. Conduction to a ground pattern formed in the mounting region 20).

  The lower surfaces of the first mounting region 20 and the second mounting region 30 are the back surfaces of the second coverlays 23 and 33 when the first mounting region 20 and the second mounting region 30 are formed as double-sided flexible boards (see FIG. 6 (C)), and when the first mounting region 20 and the second mounting region 30 are formed as single-sided flexible substrates, they are the back surfaces of the bases 22 and 32 (see FIG. 6D).

  The material of the metal plate 60 is, for example, SUS (Stainless Used Steel). The metal plate 60 also serves as a reinforcing material for the first mounting region 20 and the second mounting region 30.

  In this embodiment, heat from the component 500 is conducted to the first mounting region 20 via the metal plate 60. Thereafter, as in the case of the second to fourth embodiments, heat is conducted from the first mounting region 20 to the region 55b through the wiring portion 55a in the connection region 50, and is radiated from the region 55b.

  Therefore, this embodiment also has no ground pattern 29 (see FIG. 4) connected to the component 500 or a ground pattern passing through the vicinity of the component 500, or even if such a ground pattern exists. This is particularly useful when the width of is narrow. That is, in the case where there is no grounding pattern that can be used for heat conduction from the component 500 to the first mounting region 20 as in the third embodiment, the third embodiment is performed by attaching the metal plate 60. The same effect as that of the case of can be obtained.

  Note that this embodiment is useful when the component 500 that generates heat is mounted in the second mounting region 30 and also when the heat generating component is mounted in the first mounting region 20. This is because the heat from the heat-generating component mounted in the first mounting region 20 is also conducted to the region 55b through the wiring portion 55a in the connection region 50 as in the second to fourth embodiments. In addition, providing the ground pattern 55 in the connection region 50 that connects the two regions (the first mounting region 20 and the third mounting region 40) is an example. A non-connection region may be newly provided, and the ground pattern 55 may be provided there.

Embodiment 6 FIG.
FIG. 7 is a sectional view showing a sixth embodiment of the heat dissipation structure according to the present invention. As shown in FIG. 7, a component 500 that generates heat is mounted on the first flexible wiring board 70, and heat radiation similar to that in the first embodiment shown in FIG. There is an area.

  FIG. 7A shows the case where the second flexible wiring board 80 is formed as a double-sided flexible board, and FIG. 7B shows the case where the second flexible wiring board 80 is formed as a single-sided flexible board.

  The first flexible wiring board 70 includes, from the top, a first cover lay 71, a wiring pattern 74 as a signal line made of metal, a base (base material) 72, a wiring pattern (GND pattern) 78 made of metal, and a second cover This is a structure in which the rays 73 are stacked. The metal of the material of the wiring patterns 74 and 78 is, for example, copper, and specifically, the pattern is formed as a copper foil. The material of the first coverlay 71, the base 72, and the second coverlay 73 is, for example, polyimide.

  In the example shown in FIG. 7A, the second flexible wiring board 80 includes a first cover lay 81, a wiring pattern 84 as a signal line made of metal, and a base (base material) from the upper surface (lower side in FIG. 7). ) 82, a metal ground pattern 85, and a second coverlay 83 are laminated. In the example shown in FIG. 7B, the second flexible wiring board 80 includes a first cover lay 81, a metal ground pattern 85, and a base (base material) 82 from the upper surface (lower side in FIG. 7). It is a laminated structure. The metal of the material of the wiring pattern 84 and the ground pattern 85 is, for example, copper, and specifically, the pattern is formed as a copper foil. The material of the first cover lay 81, the base 82, and the second cover lay 83 is, for example, polyimide.

  In the first flexible wiring board 70, a metal plate 61 is pasted on the surface facing the second flexible wiring board 80, and in the second flexible wiring board 80, the metal plate 62 is placed on the surface facing the first flexible wiring board 70. Is pasted. Furthermore, the metal plate 61 and the metal plate 62 are bonded together. The material of the metal plates 61 and 62 is SUS, for example.

  Heat from the component 500 is conducted from the first flexible wiring board 70 to the metal plate 61 and further conducted to the metal plate 62. Then, it is conducted to the ground pattern 85 in the second flexible wiring board 80.

  In the second flexible wiring board 80, the ground pattern 85 is formed in the same manner as the ground pattern 15 in the first embodiment (see FIG. 1B). That is, the ground pattern 85 has a large area similar to the region 15b shown in FIG. However, in the state shown in FIG. 7, the ground pattern 15 shown in FIG. 1B is formed in a shape rotated 180 degrees.

  Similar to the first embodiment, the heat conducted to the ground pattern 85 is conducted to a large area. Then, heat is radiated from the wide area region to the outside of the second flexible wiring board 80 via the first cover lay 81. In the second flexible wiring board 80, the ground pattern 85 is formed in a wide range. In other words, the heat dissipation area is wide. Therefore, the heat dissipation effect is greater than when the ground pattern 85 is not provided.

  In this embodiment, the ground pattern 85 having a wide area is formed on the second flexible wiring board 80. However, the ground pattern 85 having a wide area is not formed, and the second flexible wiring board 80 is not formed. The conducted heat may be further conducted to another region. For example, when the connection region 50 in the second to fifth embodiments exists in the second flexible wiring board 80, a ground pattern 55 having a large area is formed in the connection region 50, and the second flexible wiring board 80 is formed. The conducted heat may be further conducted to the connection region 50 and radiated from the connection region 50.

Embodiment 7 FIG.
FIG. 8 is a plan view and a sectional view showing a seventh embodiment of the heat dissipation structure according to the present invention. FIG. 8A is a plan view when the lower surface of the flexible wiring board 207 (back side of the mounting surface of the component 500) is viewed.

  As in the fifth embodiment shown in FIG. 6, the flexible wiring board 207 has a first mounting area 20 and a second mounting area 30, and the first mounting area 20 and the third mounting area 40 (FIG. A connection region 50 is provided between the connection region 50 (not shown in FIG. 8). Therefore, the structures of the first mounting area 20, the third mounting area 40, and the connection area 50 are the same as those shown in FIG. The first mounting area 20, the third mounting area 40, and the connection area 50 are each a part of one flexible wiring board 207. In addition, providing the ground pattern 55 in the connection region 50 that connects the two regions (the first mounting region 20 and the third mounting region 40) is an example. A non-connection region may be newly provided, and the ground pattern 55 may be provided there.

  Further, as shown in FIG. 8A, the component 500 having a large amount of heat generation is mounted in the second mounting region 30.

  In this embodiment, when the flexible printed circuit board 207 is accommodated, the first mounting area 20 and the second mounting area 30 are bent. FIG. 8B is a cross-sectional view taken along the line CC of FIG. 8A in a state where the space between the first mounting region 20 and the second mounting region 30 is bent at a bent portion indicated by a broken line. It is sectional drawing shown. In addition, in FIG. 8B, the length between the first mounting area 20 and the second mounting area 30 is the first mounting area 20 in FIG. 8A so that the folded state can be easily grasped. And the length between the second mounting area 30 is shown.

  In the first mounting region 20, the metal plate 61 is pasted on the surface facing the second mounting region 30 after being bent, and in the second mounting region 30, the metal plate 62 is disposed on the surface facing the first mounting region 20. Is pasted. Furthermore, the metal plate 61 and the metal plate 62 are bonded together.

  The heat from the component 500 is conducted from the first mounting region 20 to the metal plate 61 and further conducted to the metal plate 62. Then, it is conducted from the metal plate 62 to the second mounting region 30. Thereafter, as in the case of the second to fifth embodiments, heat is conducted from the first mounting region 20 to the region 55b through the wiring portion 55a in the connection region 50, and is radiated from the region 55b.

  In this embodiment, by attaching the metal plates 61 and 62 and further bonding them together, the heat from the component 500 can be effectively conducted to the region 55b in the connection region 50 and radiated.

  Note that this embodiment is useful when the component 500 that generates heat is mounted in the second mounting region 30 and also when the heat generating component is mounted in the first mounting region 20. This is because the heat from the heat-generating component mounted in the first mounting region 20 is conducted to the region 55b through the wiring portion 55a in the connection region 50 as in the case of the second to fifth embodiments.

  Further, although the connection region 50 exists in this embodiment, when there is no connection region 50 capable of forming the ground pattern 55, the same as the heat dissipation area (see FIG. 7) in the sixth embodiment. By forming the heat dissipating area of the structure in the second mounting region 30, the heat from the component 500 can be dissipated from the heat dissipating area.

  In each of the above-described embodiments, the specific conduction pattern provided with the large area for heat dissipation is the ground pattern. However, the wide area is defined as a conduction pattern other than the ground pattern, for example, a power supply pattern or a signal. You may form in the conduction pattern as a line (other than a power supply line and a ground line).

  In the second to fifth embodiments c, in the connection region 50, the ground pattern 55 is different from the mounting side (surface side) of the component 500 mounted in the first mounting region 20 or the second mounting region 30. Although formed on the opposite side (back side), it may be formed on the same side as the mounting side of the component 500. In that case, referring to FIG. 3, for example, the ground pattern 55 appears in FIG. 3A and the signal wiring pattern 90 appears in FIG. 3B.

  In each of the above embodiments, a flexible wiring board is taken as an example of the wiring board. However, in embodiments other than the seventh embodiment (see FIG. 8), a rigid base using an epoxy resin or the like is used. Even if it is a (hard) wiring board, the heat dissipation structure according to the present invention can be applied.

  FIG. 9 is a perspective view showing an example of a mobile phone to which the heat dissipation structure according to the present invention can be applied. As shown in FIG. 9, the mobile phone 700 includes a display unit side body 710 including a display unit 720 and an operation unit side body 730 including an operation unit 740 having a plurality of key buttons. The display unit side body 710 and the operation unit side body 730 are rotatably connected by a hinge part 711 having an opening / closing axis.

  The operation unit side body 730 is provided with an outer camera module (not shown) and an inner camera module 750. The outer camera module and the inner camera module 750 (hereinafter each referred to as a camera module) each include an LED.

  Taking the heat dissipation structure of the seventh embodiment shown in FIG. 8 as an example, for example, an LED in a camera module is mounted in the first mounting region 20. In the second mounting area 30, for example, a power circuit is mounted. LEDs and power supply circuits are components that generate a large amount of heat.

  When the heat dissipation structure of the seventh embodiment is adopted, the heat generated by the LED and the power supply circuit is conducted from the first mounting region 20 to the large area 55b through the wiring portion 55a, and from the area 55b. Heat is radiated to the space in the housing. Therefore, the degree to which the housing is heated is reduced. Such an effect is also obtained when the heat dissipation structure of another embodiment other than the seventh embodiment is employed.

  INDUSTRIAL APPLICABILITY The present invention can be effectively applied as a structure that dissipates heat from a circuit component that generates a large amount of heat that is accommodated in a mobile phone or the like having a small volume in the housing to the space in the housing.

It is the top view and sectional drawing which show 1st Embodiment of a thermal radiation structure. It is sectional drawing which shows the modification of 1st Embodiment. It is the top view and sectional drawing which show 2nd Embodiment of a thermal radiation structure. It is a top view which shows 3rd Embodiment of a thermal radiation structure. It is the top view and sectional drawing which show 4th Embodiment of a thermal radiation structure. It is the top view and sectional drawing which show 5th Embodiment of a thermal radiation structure. It is sectional drawing which shows 6th Embodiment of a thermal radiation structure. It is the top view and sectional drawing which show 7th Embodiment of a thermal radiation structure. It is a perspective view which shows an example of a mobile telephone.

Explanation of symbols

11, 21, 31, 51, 71, 81 First coverlay 12, 22, 32, 52, 72, 72 Base (base material)
13, 23, 33, 53, 73, 83 Second coverlay 14, 24, 74, 84 Wiring pattern 15, 35, 55 Grounding pattern 60, 61, 62 Metal plate 70 First flexible wiring board 80 Second flexible wiring Substrate 100 Flexible wiring board 202 to 207 Flexible wiring board 500 Circuit component (heat generating component)
700 Mobile phone

Claims (9)

In the heat dissipation structure that dissipates the heat generated by the heat generating components mounted on the wiring board,
A heat dissipation structure characterized in that a wide area region of a specific conduction pattern is provided in a layer different from a layer provided with a signal wiring pattern on a wiring board on which a heat generating component is mounted. In the heat dissipation structure that dissipates the heat generated by the heat generating components mounted on the wiring board,
The wiring board has a first mounting region on which the heat-generating component is mounted, and a connection region provided with a signal wiring pattern that electrically connects the first mounting region to another region,
The connection region includes a layer provided with the signal wiring pattern and another layer,
A wide area region connected to a specific conduction pattern in the first mounting region is provided in the other layer. In the heat dissipation structure that dissipates the heat generated by the heat generating components mounted on the wiring board,
The wiring board is connected to the first mounting region, a connection region provided with a signal wiring pattern for electrically connecting the first mounting region and another region, and a heating component mounted thereon. A second mounting area,
The connection region includes a layer provided with the signal wiring pattern and another layer,
In the other layer, a wide area region connected to the specific conduction pattern of the first mounting region is provided,
A heat radiating structure is provided, wherein heat conduction means is provided to conduct heat generated by the heat generating component to a specific conduction pattern in the first mounting region. The heat dissipation structure according to claim 3, wherein the heat conducting means is a specific conduction pattern in the second mounting region. The second mounting region includes a layer provided with the signal wiring pattern and another layer,
The heat dissipation structure according to claim 3, wherein the heat conduction means is a conduction pattern formed in the other layer and connected to a specific conduction pattern in the first mounting region. The heat dissipation structure according to claim 3, wherein the heat conducting means is a metal member bonded to the first mounting region and the second mounting region. The second mounting area is bent with respect to the first mounting area at the bent portion,
The heat conduction means includes a first metal member attached to the first mounting region and a second metal member attached to the second mounting region,
The heat dissipation structure according to claim 3, wherein the first metal member and the second metal member are bonded together. In the heat dissipation structure that dissipates the heat generated by the heat generating components mounted on the wiring board,
A first wiring board on which a heat-generating component is mounted; and a second wiring board on which a large area region of a specific conduction pattern is provided,
A heat dissipating structure comprising heat conduction means for conducting heat generated by the heat generating component to the large area. The heat conducting means includes a first metal member affixed to the first wiring board and a second metal member affixed to the second wiring board,
The heat dissipation structure according to claim 8, wherein the first metal member and the second metal member are bonded together.

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