electronic machinery

Abstract

Provided is an electronic device that increases the degree of freedom in layout for electronic components on a circuit board and is capable of suppressing noise leakage. A heat pipe (50, 150) passes through an opening (32, 132) formed in an upper substrate shield (30, 130) and extends on the outside of the upper substrate shield. An auxiliary shield (80, 180) is attached to the upper substrate shield (30, 130) and covers the opening (32, 132) in the upper substrate shield (30, 130).

Description

[Technical Field]

[0001] The present disclosure relates to electronic devices. [Background technology]

[0002] In electronic devices, heat pipes are sometimes used to dissipate heat from electronic components mounted on circuit boards. In the electronic device described in Patent Document 1 below, a plurality of fins (heat sinks) are attached to the heat pipe, and heat is dissipated from the heat sinks.

[0003] Furthermore, in electronic devices, noise countermeasures (EMI countermeasures) are taken to shield noise emitted from chips mounted on circuit boards and data transmission lines. In the electronic device described in Patent Document 2 below, the edge of a board shield that covers the circuit board comes into contact with a ground pattern provided on the outer periphery of the circuit board, thereby preventing noise from leaking outside the circuit board shield. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2021 / 193621 [Patent Document 2] Japanese Patent Application Publication No. 2018-148026 Summary of the Invention [Problem to be solved by the invention]

[0005] When a heat pipe is arranged along a circuit board, it becomes difficult to maintain a sufficient distance between the electronic components and the heat pipe, making it difficult to mount the electronic components in that area.

[0006] An object of the present disclosure is to provide an electronic device that increases the degree of freedom in the layout of electronic components on a circuit board and can suppress noise leakage. [Means for solving the problem]

[0007] The electronic device according to the present disclosure includes a circuit board, a circuit board shield covering the circuit board, a heat pipe disposed between the circuit board and the circuit board shield, and an auxiliary shield, the circuit board shield having an opening formed therein, the heat pipe extending from a space between the circuit board and the circuit board shield through the opening to the outside of the circuit board shield, and the auxiliary shield attached to the circuit board shield and covering the opening. This increases the degree of freedom in the layout of electronic components on the circuit board and suppresses noise leakage. [Brief explanation of the drawings]

[0008] [Figure 1A] 1 is a perspective view of a circuit board unit provided inside an electronic device that is an example of an embodiment of the present disclosure. [Figure 1B] FIG. 2 is a plan view of the circuit board unit. [Figure 2] FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1B. [Figure 4] FIG. 10 is a view showing the vicinity of the opening of the upper substrate shield. [Figure 5] FIG. 10 is a perspective view showing the back side of the upper substrate shield. [Figure 6] FIG. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 1B, showing a cross section of the upper substrate shield and the auxiliary shield. [Figure 8] FIG. 10 is a schematic diagram showing a cross section of an upper substrate shield and an auxiliary shield in another example of the present embodiment. [Figure 9] FIG. 10 is a plan view of an auxiliary shield in another example of the present embodiment. [Figure 10] FIG. 10 is a plan view illustrating a portion of a circuit board unit provided inside an electronic device that is another example of an embodiment of the present disclosure. [Figure 11] FIG. [Figure 12] FIG. 10 is a plan view showing a state in which the auxiliary shield is removed from the upper substrate shield. [Figure 13] FIG. 11 is a cross-sectional view taken along line XIII-XIII in FIG. [Figure 14] FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. [Figure 15] FIG. 11 is a cross-sectional view taken along line XV-XV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] [1. First embodiment] [1-1. Overview of the circuit board unit] FIG. 1A is a perspective view showing the front side (upper side) of a circuit board unit 10 provided inside an electronic device that is an example (first embodiment) of an embodiment of the present disclosure. FIG. 1B is a plan view of the circuit board unit 10. FIG. 2 is an exploded perspective view showing components of the circuit board unit 10. As shown in each drawing, the circuit board unit 10 has a circuit board 20, a first circuit board shield 30, and a second circuit board shield 40. As shown in FIG. 2, the circuit board 20 is flat and has a first surface 20U and a second surface 20D (see FIG. 3) that is the back surface of the first surface 20U of the circuit board 20. The first circuit board shield 30 covers the first surface 20U of the circuit board 20. The second circuit board shield 40 covers the second surface 20D of the circuit board 20.

[0010] In the following description, the Z1 and Z2 directions of the Z axis shown in FIG. 2 and other figures are referred to as the upper and lower directions, respectively. The first surface 20U of the circuit board 20 is referred to as the upper surface 20U, and the second surface 20D of the circuit board 20 is referred to as the lower surface 20D. The first circuit board shield 30 is referred to as the upper board shield 30, and the second circuit board shield 40 is referred to as the lower board shield 40. In the following description, an example will be described in which the circuit board 20 has outer edges 20F and 20D along the X axis and outer edges 20R and 20L along the Y axis shown in FIG. 2 and other figures. The X1 and X2 directions of the X axis shown in FIG. 2 and other figures are referred to as the left and right directions, respectively, and the Y1 and Y2 directions of the Y axis are referred to as the front and rear, respectively. The front outer edge 20F, rear outer edge 20D, left outer edge 20L, and right outer edge 20R of the circuit board 20 may also be referred to as the front edge 20F, rear edge 20D, left edge 20L, and right edge 20R, respectively. However, these directions and positions are specified to explain the shapes and relative positional relationships of elements such as parts, components, and portions of the circuit board unit 10, and do not limit the orientation of the circuit board unit 10 in the electronic device.

[0011] [1-2. Internal structure of the circuit board unit] As shown in FIG. 2, electronic components such as multiple chips 21 are mounted on the upper surface 20U of the circuit board 20. Furthermore, multiple electronic components (not shown) are also mounted on the lower surface 20D of the circuit board 20. Noise, such as electromagnetic waves, is generated from these electronic components and data transmission paths. The upper and lower board shields 30 and 40 (hereinafter sometimes simply referred to as board shields 30 and 40) are intended to prevent noise generated on the circuit board 20 from leaking outside the circuit board unit 10, and cover the upper and lower surfaces 20U and 20D of the circuit board 20. The board shields 30 and 40 can be manufactured by performing sheet metal processing, such as drawing, on conductive metal plates made of iron or aluminum. The board shields 30 and 40 are fixed to the circuit board 20 with fasteners such as screws or rivets.

[0012] 2, the circuit board unit 10 has a heat pipe 50 extending in a rod shape along the circuit board 20, and a heat sink 60 attached to the heat pipe. The heat pipe 50 and the heat sink 60 are used to cool the multiple chips 21 and are made of a metal with high thermal conductivity, such as aluminum, copper, or stainless steel. The heat sink 60 may be fixed to the upper surface 30U, which is the front surface of the upper substrate shield 30, by being pressed against a component (such as a cover or frame) of the electronic device (not shown). The heat sink 60 may also be fixed to the upper surface 30U of the upper substrate shield 30 by soldering or the like.

[0013] In this embodiment, the multiple chips 21 are transistors such as FETs (Field Effect Transistors) that generate driving power for the processor mounted on the circuit board 20 from the power supplied from the power supply unit 60, but the electronic components cooled by the heat pipes 50 and heat sinks 60 are not limited to transistors; for example, the heat pipes 50 and heat sinks 60 may be used to cool a processor or a memory.

[0014] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1B. As shown in FIG. 1B, the heat pipe 50 has a heat receiving portion 51 positioned away from the heat sink 60. As shown in FIG. 3, the heat receiving portion 51 of the heat pipe 50 is disposed between the circuit board 20 and the upper board shield 30. The heat receiving portion 51 contacts the multiple chips 21 mounted on the upper surface 20U of the circuit board 20, thereby receiving heat generated by these chips 21. As shown in FIG. 2, the multiple chips 21 are aligned in the front-rear direction along the left edge 20L of the circuit board 20. The heat receiving portion 51 extends in the front-rear direction so as to cover the multiple chips 21. A reinforcing metal fitting 70 (see FIG. 5) is attached to the heat receiving portion 51. The reinforcing metal fitting 70 may be attached to the lower surface 51D of the heat receiving portion 51 by soldering or the like.

[0015] 1B, the heat pipe 50 has an attachment portion 52 to which the heat sink 60 is attached, on the side opposite the heat receiving portion 51. The attachment portion 52 of the heat pipe 50 is located between the heat sink 60 and the upper board shield 30, and extends in the left-right direction. A recess 61 (see FIG. 2) that is recessed upward is formed on the underside of the heat sink 60. The recess 61 extends in the left-right direction, and the inside of this recess 61 is attached to the attachment portion 52 of the heat pipe 50.

[0016] The heat sink 60 is disposed in an air flow path formed in the housing that accommodates the circuit board unit 10, and is cooled by the air. This cools the heat pipes 50 attached to the heat sink 60, and also cools the multiple chips 21 that are in contact with the heat receiving portions 51 of the heat pipes 50. In this way, cooling of the multiple chips 21 is achieved.

[0017] An opening 32 (see FIG. 2) is formed in the upper board shield 30. FIG. 4 is a diagram showing the vicinity of the opening 32 of the upper board shield 30, and shows a state in which an auxiliary shield 80, which will be described later, has been removed from the upper board shield 30. An accommodating recess 31 (see FIG. 3) in which a heat receiving portion 51 of the heat pipe 50 is disposed is formed on the lower surface (surface on the circuit board 20 side) of the upper board shield 30. The opening 32 is formed behind the accommodating recess 31, and as shown in FIG. 2, is open in two directions, that is, in the front-to-rear and up-to-down directions. As shown in FIG. 4, a recess 32a recessed rearward is formed on the rear edge of the opening 32.

[0018] The heat pipe 50 extends from a space S (see FIG. 3) defined between the circuit board 20 and the accommodating recess 31 of the upper board shield 30 to the outside (front side) of the upper board shield 30, passing through the opening 32, as shown in FIGS. 1A and 2. In this way, by providing the opening 32 in the upper board shield 30 and extending the heat pipe 50 from this opening 32 to the outside of the upper board shield 30, the heat pipe 50 can be extended in a direction away from the circuit board 20. This allows for greater freedom in the layout of electronic components mounted on the circuit board 20.

[0019] Furthermore, by forming the opening 32 in the upper substrate shield 30 through which the heat pipe 50 passes, the size of the opening required to expose the cooling system, including the heat sink 60, on the upper side of the upper substrate shield 30 can be reduced. For example, if only the heat sink 60 is exposed from the upper substrate shield 30, an opening corresponding to the size of the heat sink 60 must be formed in the upper substrate shield 30. In contrast, with a structure in which the heat pipe 50 passes inside the opening 32, the size of the opening 32 formed in the upper substrate shield 30 can be reduced. By reducing the size of the opening 32 in this way, it becomes easier to take measures against noise at the opening 32.

[0020] 5 is a perspective view showing the back side (lower side, circuit board 20 side) of the upper substrate shield 30. As shown in FIGS. 3 and 5, an accommodating recess 31 recessed upward is formed in the lower surface 30D, which is the back surface of the upper substrate shield 30. The accommodating recess 31 extends in the front-to-rear direction (direction along the Y axis) at the positions of the multiple chips 21 mounted on the circuit board 20, and the heat receiving portion 51 of the heat pipe 50 is disposed inside the accommodating recess 31.

[0021] As shown in FIG. 5 , the auxiliary metal fitting 70 attached to the heat receiving portion 51 of the heat pipe 50 is flat and extends in the front-rear direction (along the Y-axis) along the extension direction of the heat receiving portion 51. The auxiliary metal fitting 70 has multiple auxiliary heat receiving portions 71 between the multiple chips 21 and the lower surface 51D of the heat receiving portion 51. The auxiliary heat receiving portions 71 are disposed on the chips 21 and conduct heat received from the chips 21 to the heat receiving portion 51. In this way, the auxiliary heat receiving portions 71 provided on the auxiliary metal fitting 70 receive heat from the chip 21 at a position closer to the chip 21 than the heat receiving portion 51 of the heat pipe 50, thereby more effectively absorbing heat from the chip 21 and cooling the chip 21. The auxiliary heat receiving portions 71 may be attached to the chip 21 by soldering or the like in contact with the chip 21. A gap C1 is formed between two adjacent auxiliary heat receiving portions 71. By providing this gap C1, it is possible to avoid interference between the auxiliary bracket 70 and other electronic components mounted on the upper surface 20U of the circuit board 20 (electronic components not shown that are arranged between two adjacent chips 21).

[0022] 5, a protrusion 72 that protrudes rearward is formed at the rear end (the end on the Y2 direction side) of the reinforcing bracket 70. The protrusion 72 of the reinforcing bracket 70 fits inside a recess 32a that is formed at the rear edge of the opening 32 of the upper board shield 30. By forming the protrusion 72 at the rear end of the reinforcing bracket 70 and the recess 32a in the upper board shield 30 in this way, it becomes easy to position the reinforcing bracket 70 and the upper board shield 30 at the rear end of the reinforcing bracket 70. Furthermore, at the rear end of the reinforcing bracket 70, it is possible to prevent the reinforcing bracket 70 and the heat receiving portion 51 of the heat pipe 50 attached thereto from moving along the underside 30D of the upper board shield 30.

[0023] 5, a guide hole 73 is formed in the front end (the end on the Y1 direction side) of the reinforcing bracket 70, and a convex portion 38 that protrudes downward is formed on the underside 30D of the upper board shield 30. The guide convex portion 38 of the upper board shield 30 fits into the guide hole 73 of the reinforcing bracket 70, making it easy to position the reinforcing bracket 70 and the upper board shield 30 at the front end of the reinforcing bracket 70. The guide convex portion 38 and guide hole 73 described above determine the position of the reinforcing bracket 70 on the upper board shield 30 in the front-to-back and left-to-right directions, and the convex portion 72 of the reinforcing bracket 70 and the concave portion 32a of the upper board shield 30 determine the position of the reinforcing bracket 70 in the rotational direction around the guide convex portion 38.

[0024] 3, an upwardly protruding mounting protrusion 74 is formed at the front end of the reinforcing bracket 70 (more specifically, in front of the guide hole 73), and a mounting hole 39 is formed in the upper board shield 30. The upwardly protruding mounting protrusion 74 fits into the mounting hole 39 of the upper board shield 30, and is formed in a flange shape so that it catches on the edge of the mounting hole 39. This makes it possible to attach the front end of the reinforcing bracket 70 to the upper board shield 30.

[0025] The mounting protrusion 74 of the auxiliary bracket 70 is formed by sheet metal processing that pushes the auxiliary bracket 70 out from below. As a result, a recess 75 that is larger than the mounting protrusion 74 in plan view is formed on the opposite side of the auxiliary bracket 70 from the mounting protrusion 74. Furthermore, when the top of the mounting protrusion 74 is pressed downward, it is formed into a flange shape that catches on the edge of the mounting hole 39 in the upper board shield 30, and is fixed to the mounting hole 39 in the upper board shield 30.

[0026] [1-3. Noise countermeasures using auxiliary shields] As shown in FIG. 2, the circuit board unit 10 has an auxiliary shield 80. The auxiliary shield 80 has a recess 81 that is recessed upward. Like the board shields 30 and 40, the auxiliary shield 80 may be manufactured by performing sheet metal processing on a conductive metal plate such as iron or aluminum. As shown in FIGS. 1A and 2, the auxiliary shield 80 is attached to the upper board shield 30 and covers the opening 32 formed in the upper board shield 30. By covering the opening 32 of the upper board shield 30 with the auxiliary shield 80 in this manner, it is possible to prevent noise from leaking from the opening 32 to the outside of the upper board shield 30.

[0027] As shown in FIG. 2 , the upper surface 30U of the upper board shield 30 has a guide recess 33 recessed downward along the outer edge of the auxiliary shield 80. Forming the guide recess 33 in the upper board shield 30 facilitates positioning of the auxiliary shield 80 on the upper board shield 30, facilitating installation of the auxiliary shield 80. Furthermore, the upper surface 30U of the upper board shield 30 has an outer recess 34 recessed downward along the heat pipe 50. By arranging the heat pipe 50 in this outer recess 34, it is possible to prevent the heat pipe 50 from moving along the upper surface 30U of the upper board shield 30. Furthermore, by forming the outer recess 34, it is not necessary to bend the heat pipe 50 upward to arrange it above the upper board shield 30. As a result, the shape of the auxiliary shield 80 that covers the opening 32 and the heat pipe 50 in its surrounding area can be simplified.

[0028] 4, the heat pipe 50 has a passage portion 53 that passes through the opening 32 from the outside of the upper board shield 30. The auxiliary shield 80 covers the passage portion 53 of the heat pipe 50 in the plan view shown in FIG. 4. The passage portion 53 of the heat pipe 50 is disposed outside the upper board shield 30, between the guide recess 33 of the upper board shield 30 and the auxiliary shield 80.

[0029] Fig. 6 is a plan view of the auxiliary shield 80. Note that in Fig. 6, the position of the opening 32 of the upper board shield 30 that is covered by the auxiliary shield 80 is indicated by a dotted line. As shown in Fig. 6, the recess 81 that is recessed upward in the auxiliary shield 80 is formed along the passage portion 53 of the heat pipe 50. In this way, the gap between the auxiliary shield 80 and the heat pipe 50 can be narrowed, and noise leakage from between the auxiliary shield 80 and the heat pipe 50 can be suppressed.

[0030] 2 and 4, in the upper board shield 30, at least a portion of the outer recess 34 is also formed in the guide recess 33. As shown in Fig. 4, the front end of the outer recess 34 is connected to the opening 32 formed inside the guide recess 33. In this way, the gap between the upper board shield 30 and the heat pipe 50 at the edge of the opening 32 can be narrowed, and noise leakage from between the upper board shield 30 and the heat pipe 50 can be suppressed.

[0031] As shown in FIG. 6 , the auxiliary shield 80 has a fixing portion 82 that is fixed to the upper board shield 30 by a fixing device such as a screw or a rivet. Furthermore, as shown in FIG. 4 , the upper board shield 30 also has a fixing portion 36 that is fixed to the auxiliary shield 80 by a fixing device. The fixing portions 36, 82 may be holes formed at the same position in a plan view of the circuit board unit 10, and a single fixing device may be attached to this hole. For example, by fastening the auxiliary shield 80 and the upper board shield 30 with a single screw, the auxiliary shield 80 comes into contact with the upper board shield 30 at the fixing portions 36, 82. In this way, noise blocking performance can be improved at the fixing portions 36, 82 where the auxiliary shield 80 comes into contact with the upper board shield 30.

[0032] 7 is a cross-sectional view taken along line VII-VII in FIG. 1B, showing the cross sections of the upper board shield 30 and the auxiliary shield 80. As shown in FIGS. 4 and 7, the upper board shield 30 has a protrusion 37 that protrudes upward inside the guide recess 33. The protrusion 37 (first protrusion) may be formed by subjecting the upper board shield 30 to sheet metal processing. This makes it easy to form the protrusion 37 on the upper board shield 30. Alternatively, the protrusion 37 may be formed by placing a conductive member such as solder on the guide recess 33 of the upper board shield 30.

[0033] As shown in FIGS. 6 and 7 , the auxiliary shield 80 has a contact portion 83 that contacts the upper board shield 30 via the protrusion 37. The auxiliary shield 80 may bend relative to the upper board shield 30, thereby allowing the contact portion 83 of the auxiliary shield 80 to be in stable contact with the protrusion 37. To allow this bending, the auxiliary shield 80 is desirably softer than the upper board shield 30 on which the protrusion 62 is formed. In the example shown in FIG. 7 , the thickness of the auxiliary shield 80 in the vertical direction is smaller than the thickness of the upper board shield 30. However, the auxiliary shield 80 may be formed of a material (e.g., aluminum) that is softer than the material (e.g., iron) of the lower board shield 40. By providing the protrusion 37 and the contact portion 83 in this manner, the stability of the contact between the upper board shield 30 and the auxiliary shield 80 can be sufficiently ensured, and noise blocking performance can be improved at the positions of the protrusion 37 and the contact portion 83.

[0034] As shown in FIG. 6 , the auxiliary shield 80 has a fixing portion 82 fixed to the upper circuit board shield 30 and a contact portion 83 spaced apart from the fixing portion 82 in the front-rear direction (direction along the Y-axis), which is the extension direction of the passing portion 53 of the heat pipe 50, on at least one of the left and right sides of the passing portion 53. In other words, the upper circuit board shield 30 has a fixing portion 36 fixed to the auxiliary shield 80 and a protruding portion 37 in contact with the auxiliary shield 80, on at least one of the left and right sides of the heat pipe 50. The auxiliary shield 80 has two fixing portions 82 on at least one of the left and right sides of the passing portion 53 of the heat pipe 50, and the upper circuit board shield 30 has two fixing portions 36 at the same positions as the two fixing portions 82 in a plan view. The protruding portion 37 and the contact portion 53 are formed between the two fixing portions 82 (fixing portions 36).

[0035] 6, the auxiliary shield 80 has a fixing portion 82 and a contact portion 83 on both the left and right sides of the passing portion 53 of the heat pipe 50. The upper board shield 30 also has a fixing portion 36 and a protruding portion 37 on both the left and right sides of the passing portion 53. This is not limiting, and in the auxiliary shield 80, the fixing portion 82 and the contact portion 83 may be formed on one of the left and right sides of the passing portion 53, with only the fixing portion 82 being formed on the other side. Similarly, in the upper board shield 30, the fixing portion 36 and the protruding portion 37 may be formed on one of the left and right sides of the heat pipe 50, with only the fixing portion 36 being formed on the other side.

[0036] On the left and right sides of the heat pipe 50, the distance d1 between the fixing portion 82 and the contact portion 83 formed on the auxiliary shield 80 (i.e., the distance d1 between the fixing portion 36 and the protrusion 37 formed on the upper board shield 30) is desirably determined based on the wavelength of noise whose leakage to the outside of the upper board shield 30 is to be suppressed. The distance d1 may be set to less than one-third, and more preferably less than one-quarter, of the wavelength of the noise to be blocked by the upper board shield 30 and the auxiliary shield 80. For example, by setting the distance d1 to 20 mm or less, leakage of noise in the frequency band used in wireless communication, etc. can be effectively suppressed. More preferably, the distance d1 may be set to 15 mm or less. Even more preferably, the distance d1 may be set to 10 mm or less.

[0037] In the example shown in Fig. 6, fixing portions 82 are formed at four corners of the auxiliary shield 80: the front left, rear left, front right, and rear right. Four fixing portions 36 of the upper board shield 30 are formed at positions corresponding to the four fixing portions 82. A protrusion 37 and a contact portion 83 are provided between two fixing portions 82 located at the two front left and rear left corners and between two fixing portions 82 located at the two front right and rear right corners. Note that, in the example shown in Fig. 6, there is one protrusion 37 and one contact portion 83 disposed between two fixing portions 82, but there may be more than one protrusion 37 and one contact portion 83 disposed between two fixing portions 82.

[0038] 8 is a schematic diagram showing cross sections of the upper board shield 30 and auxiliary shield 80 in another example of this embodiment, and shows an outline of a cross section obtained by cutting along a front-to-rear direction passing through the fixing portions 36, 82, the protrusion 37, and the contact portion 83. As shown in FIG. 8, the auxiliary shield 80 comes into contact with the upper board shield 30 by being pressed against the upper board shield 30 by a fixing portion H such as a screw at the position of the fixing portion 36. Then, the auxiliary shield 80 may bend relative to the upper board shield 30, so that the contact portion 83 of the auxiliary shield 80 comes into contact with the protrusion 37.

[0039] Here, the auxiliary shield 80 may bend upward as the contact portions 83 are lifted by the protrusions 37, forming a gap C2 between the two protrusions 37. If the number of protrusions 37 formed between the two fixing portions 36 in the upper board shield 30 is set to three, the protrusion 37 between two of these three protrusions 37 may be located near the gap C2. For this reason, it is desirable to limit the number of protrusions 37 located between two adjacent fixing portions 36 to two or less. In other words, it is desirable to limit the number of contact portions 83 provided between two adjacent fixing portions 82 in the auxiliary shield 80 to two or less. This ensures sufficient stability of contact between the upper board shield 30 and the auxiliary shield 80, thereby improving the performance of blocking noise generated on the circuit board 20.

[0040] The passage portion 53 of the heat pipe 50 (see FIG. 4) extends rearward (in a first direction) from the space S (see FIG. 3) between the circuit board 20 and the upper board shield 30, passing through the opening 32 from the outside of the upper board shield 30. As shown in FIG. 6, the recess 81 of the auxiliary shield 80 has a first overlapping portion 81B located rearward of the opening 32 of the upper board shield 30 and covering the passage portion 53 of the heat pipe, and a second overlapping portion 81F located forward of the opening 32 (in a direction opposite to the first direction) and covering the passage portion 53 of the heat pipe 50. A width D1 in the front-to-rear direction of the first overlapping portion 81B is greater than a width D2 in the front-to-rear direction of the second overlapping portion 81F.

[0041] Noise generated from electronic components such as chip 21 mounted on upper surface 20U of circuit board 20 is radiated in a direction away from the electronic components, and some of the noise is radiated rearward from opening 32 (see FIG. 4) in upper board shield 30. For this reason, as shown in FIG. 6, by making width D1 where auxiliary shield 80 and heat pipe 50 overlap behind opening 32 larger than width D2 where auxiliary shield 80 and heat pipe 50 overlap in front of opening 32, noise radiated rearward from opening 32 can be more effectively shielded.

[0042] 6, in the recess 81 of the auxiliary shield 80, the first overlapping portion 81B covering the heat pipe 50 is slightly curved to the right (direction X2) along the outer edge of the heat pipe 50. This makes it easier to reflect noise such as electromagnetic waves that travel straight backward from the opening 32 (see FIG. 4) of the upper board shield 30, thereby improving noise blocking performance.

[0043] [1-4. Summary] As described above, in this embodiment, the heat pipe 50 extends from the space S between the circuit board 20 and the upper board shield 30, passing through the opening 32 formed in the upper board shield 30, to the outside of the upper circuit board shield 30. This allows the heat pipe 50 to extend in a direction away from the circuit board 20, increasing the degree of freedom in the layout of electronic components mounted on the circuit board 20.

[0044] Furthermore, in this embodiment, the auxiliary shield 80 is attached to the upper substrate shield 30 and covers the opening 32 formed in the upper substrate shield 30. In this way, it is possible to prevent noise from leaking from the opening 32 to the outside of the upper substrate shield 30.

[0045] It should be noted that the present invention is not limited to the above-described embodiments.

[0046] FIG. 9 is a plan view of an auxiliary shield 80 in another example of this embodiment. In the example shown in FIG. 9 , the auxiliary shield 80 also has a fixing portion 82 fixed to the upper circuit board shield 30 and a contact portion 83 that contacts the protrusion 37 of the upper circuit board shield 30. The auxiliary shield 80 has two contact portions 83 on at least one of the left and right sides of the heat pipe 50, and the fixing portion 82 is formed between the two contact portions 83. That is, the upper board shield 30 has two protrusions 37 on at least one of the left and right sides of the heat pipe 50, and the fixing portion 36 is formed between the two protrusions 37. On one of the left and right sides of the heat pipe 50, the two protrusions 37 are provided at positions spaced apart in the front-rear direction (direction along the Y axis), and the two contact portions 83 are also provided at positions spaced apart in the front-rear direction. The fixing portions 36, 82 are formed between the two protrusions 37 that are spaced apart in the front-rear direction (between the two contact portions 83). This also ensures sufficient stability of contact between the upper board shield 30 and the auxiliary shield 80, improving noise blocking performance.

[0047] In this example as well, it is desirable to determine the distance d2 between the fixing portion 82 and the contact portion 83 formed on the auxiliary shield 80 (i.e., the distance d2 between the fixing portion 36 and the protrusion 37 formed on the upper board shield 30) based on the wavelength of noise whose leakage to the outside of the upper board shield 30 is to be suppressed. The distance d2 may be set to less than one-third, and more preferably, less than one-quarter of the wavelength of the noise to be shielded by the upper board shield 30 and the auxiliary shield 80. For example, by setting the distance d2 to 20 mm or less, it is possible to effectively suppress the leakage of noise in the frequency band used in wireless communication, etc. More preferably, the distance d2 may be set to 15 mm or less. Even more preferably, the distance d2 may be set to 10 mm or less.

[0048] [2. Second Embodiment] FIG. 10 is a plan view showing a portion of a circuit board unit 100 provided inside an electronic device that is another example (second embodiment) of an embodiment of the present disclosure. Like the circuit board unit 10 described above, the circuit board unit 100 also has an upper board shield 130 (first circuit board shield) and a circuit board and a lower board shield (second circuit board shield), not shown. The circuit board is disposed between the upper board shield 130 and the lower board shield. The upper board shield 130 and the lower board shield are intended to prevent noise, such as electromagnetic waves, generated on the circuit board from leaking outside the circuit board unit 100. The upper board shield 130 covers a first surface (upper surface) of the circuit board, and the lower board shield covers a second surface (lower surface) of the circuit board. The upper board shield 130 and the lower board shield are fixed to the circuit board by fasteners such as screws or rivets. The upper substrate shield 130 shown in FIG. 10 can also be manufactured by subjecting a conductive metal plate such as iron or aluminum to sheet metal working such as drawing.

[0049] The circuit board unit 100 also has a heat pipe 150 that extends in a rod shape along the circuit board and upper board shield 130, and a heat sink (not shown) attached to the heat pipe. The heat pipe 150 and heat sink are made of a metal with high thermal conductivity such as aluminum, copper, or stainless steel, and are used to cool electronic components such as chips and FETs mounted on the circuit board.

[0050] As shown in FIG. 10, the circuit board unit 100 has an auxiliary shield 180 attached to the upper board shield 130. FIG. 11 shows a plan view of the auxiliary shield 180 alone. The auxiliary shield 180 has a recess 181 that is recessed upward. A portion of the heat pipe 150 is housed inside this recess 181. Like the upper board shield 130 and the second board shield, the auxiliary shield 180 may be manufactured by performing sheet metal processing on a conductive metal plate such as iron or aluminum.

[0051] Fig. 12 is a plan view showing the upper board shield 130 with the auxiliary shield 180 removed. As shown in Fig. 12, an opening 132 is formed in the upper board shield 130. The opening 132 is open in two directions, the front-rear direction and the up-down direction. In addition, a recess 132a recessed rearward is formed at the rear edge of the opening 132.

[0052] The heat pipe 150 extends from the space defined between the circuit board and the lower side (back side) of the upper substrate shield 130 through the opening 132 to the upper side (front side) of the upper substrate shield 130. This allows the heat pipe 150 to extend in a direction away from the circuit board, increasing the degree of freedom in the layout of electronic components mounted on the circuit board. Furthermore, the size of the opening 132 can be made smaller than when an opening corresponding to the size of a heat sink is formed in the upper substrate shield 130, making it easier to prevent noise leakage through the opening 132.

[0053] Fig. 13 is a cross-sectional view taken along line XIII-XIII in Fig. 10. Fig. 14 is a cross-sectional view taken along line XIV-XIV in Fig. 10. Fig. 15 is a cross-sectional view taken along line XV-XV in Fig. 10. As shown in Fig. 13, an outer recess 134 recessed downward along the heat pipe 150 is formed on the upper surface 130U of the upper substrate shield 130. By arranging the heat pipe 150 in this outer recess 134, it is possible to prevent the heat pipe 150 from moving along the upper surface 130U of the upper substrate shield 130. It is also possible to narrow the gap between the upper substrate shield 130 and the heat pipe 150, thereby preventing noise from leaking between the upper substrate shield 130 and the heat pipe 150.

[0054] As shown in FIGS. 10 and 12 , when the auxiliary shield 180 is attached to the upper substrate shield 130, it covers the opening 132 formed in the upper substrate shield 130. This makes it possible to prevent noise from leaking from the opening 132 to the outside of the upper substrate shield 130. As shown in FIG. 15 , like the heat pipe 50 described above, the heat pipe 150 also has a passing portion 153 that passes through the opening 132 of the upper substrate shield 130. The auxiliary shield 180 covers the passing portion 153 of the heat pipe 150. The passing portion 153 of the heat pipe 150 is disposed above the upper substrate shield 130, between the upper substrate shield 130 and the auxiliary shield 180. The auxiliary shield 180 also has an upwardly recessed recess 181 formed along the passing portion 153 of the heat pipe 150. In this way, the gap between the auxiliary shield 180 and the heat pipe 150 can be narrowed, and noise leakage from between the auxiliary shield 180 and the heat pipe 150 can be suppressed.

[0055] 11, the auxiliary shield 180 has a fixing portion 182 that is fixed to the upper substrate shield 130. In addition, as shown in FIG. 12, the upper substrate shield 130 also has a fixing portion 136 that is fixed to the auxiliary shield 180.

[0056] As shown in FIGS. 13 and 14 , the fixing portions 136 and 182 are formed at the same position in a plan view of the circuit board unit 100. In this embodiment, the fixing portion 182 is a hole formed in the auxiliary shield 180, and the fixing portion 136 is a protrusion that protrudes upward (toward the auxiliary shield 180) from the top surface of the upper board shield 130. The fixing portion 136 of the upper board shield 130 fits into the hole of the fixing portion 182 of the auxiliary shield 180 and is then crimped (a process of crushing in the vertical direction) to form a flange shape. The fixing portion 136 of the upper board shield 130 hooks onto the edge of the hole of the fixing portion 182. As a result, the auxiliary shield 180 is fixed to the upper board shield 130. Furthermore, the auxiliary shield 180 comes into contact with the upper board shield 130 at the positions of the fixing portions 136 and 182. This allows the noise blocking performance to be improved at the positions of the fixed portions 136 and 182.

[0057] The fixing portion 136 of the upper board shield 130 may be a hole, similar to the fixing portion 182 of the auxiliary shield 180. In this case, one fixing tool may be attached to the hole of the fixing portions 136, 182. For example, by fastening the auxiliary shield 180 and the upper board shield 130 with one screw, the auxiliary shield 180 comes into contact with the upper board shield 130 at the position of the fixing portions 136, 182. This also makes it possible to improve noise blocking performance at the position of the fixing portions 136, 182.

[0058] Like the upper board shield 30 described in the first embodiment, the upper board shield 130 also has a protrusion 137 (first protrusion, see FIG. 12 ) that protrudes upward. The protrusion 137 may be formed by subjecting the upper board shield 130 to sheet metal processing, or by placing a conductive member such as solder on the upper board shield 130. The auxiliary shield 180 has a contact portion 183 (see FIG. 11 ) that contacts the upper board shield 130 via the protrusion 137. The upper board shield 130 and the auxiliary shield 180 come into contact with each other at the positions of the protrusion 137 and the contact portion 183, thereby improving noise blocking performance at the positions of the protrusion 137 and the contact portion 183.

[0059] In the example shown in FIGS. 10 and 12 , the upper board shield 130 has a fixing portion 136 and a protruding portion 137 on both the left and right sides of the passing portion 153 of the heat pipe 150. The auxiliary shield 180 also has a fixing portion 182 and a contact portion 183 on both the left and right sides of the passing portion 153. The distance d3 between the fixing portion 182 and the contact portion 183 formed on the auxiliary shield 180 (the distance d3 between the fixing portion 136 and the protruding portion 137 formed on the upper board shield 130) on the left and right sides of the passing portion 153 is preferably determined based on the wavelength of noise whose leakage to the outside of the upper board shield 130 is to be suppressed. The distance d3 may be set to less than one-third, more preferably less than one-quarter, of the wavelength of the noise to be shielded. For example, setting the distance d3 to 20 mm or less can effectively suppress leakage of noise in the frequency band used in wireless communication, etc. More preferably, the distance d3 may be set to 15 mm or less. More preferably, the distance d1 may be set to 10 mm or less.

[0060] In the auxiliary shield 180 shown in FIG. 11 , fixing portions 182 are formed at four corners of the auxiliary shield 180: the left front, right front, left rear, and right rear. Four fixing portions 136 of the upper board shield 130 are formed at positions corresponding to the four fixing portions 182. A downwardly protruding convex portion 185 (second convex portion, see FIG. 13 ) is formed between the left front fixing portion 182 and the right front fixing portion 182 of the auxiliary shield 180. A downwardly protruding convex portion 186 (third convex portion, see FIG. 13 ) is also formed between the left rear fixing portion 182 and the right rear fixing portion 182 of the auxiliary shield 180. The convex portions 185, 186 may be formed, for example, by subjecting the auxiliary shield 180 to sheet metal processing, and the upper surface (front surface) of the auxiliary shield 180 may have recesses at the positions of the convex portions 185, 186. Alternatively, the protrusions 185 and 186 may be formed by placing a conductive member such as solder on the auxiliary shield 180.

[0061] As shown in FIGS. 10 and 13 , a downwardly protruding protrusion 185 on the front side of the auxiliary shield 180 comes into contact with the heat pipe 150 (more specifically, the passing portion 153). By forming the protrusion 185 on the auxiliary shield 180, stable contact between the auxiliary shield 180 and the heat pipe 150 can be ensured at the position of the protrusion 185, and noise blocking performance can be improved at the position of the protrusion 185. Furthermore, as shown in FIGS. 10 and 14 , a downwardly protruding protrusion 186 on the rear side of the auxiliary shield 180 comes into contact with the upper board shield 130. By forming the protrusion 186 on the auxiliary shield 180, stable contact between the auxiliary shield 180 and the upper board shield 130 can be ensured at the position of the protrusion 186, and noise blocking performance can be improved even at the position of the protrusion 186.

[0062] The auxiliary metal fitting 70 (see FIG. 13 ) described in the first embodiment may be attached to the underside of the heat pipe 150. Instead of forming the protrusion 185 (see FIG. 13 ) on the auxiliary shield 180, a protrusion (second protrusion) may be formed on the heat pipe 150 (more specifically, the passing portion 153), and the auxiliary shield 180 and the heat pipe 150 may contact each other via this protrusion. The protrusion on the heat pipe 150 may be formed by placing a conductive member such as solder on the heat pipe 150. Instead of forming the protrusion 186 (see FIG. 14 ) on the auxiliary shield 180, a protrusion (third protrusion) may be formed on the upper board shield 130 (more specifically, behind the opening 132 of the upper board shield 130), and the auxiliary shield 180 and the upper board shield 130 may contact each other via this protrusion. The protrusions of the upper substrate shield 130 may be formed by sheet metal processing of the upper substrate shield 130, or may be formed by placing a conductive member such as solder on the upper substrate shield 130.

[0063] The auxiliary shield 180 flexes relative to the upper board shield 130, allowing the contact portion 183 and the protrusion 186 of the auxiliary shield 180 to stably contact the upper board shield 130. Furthermore, the auxiliary shield 180 flexes, allowing the protrusion 185 of the auxiliary shield 180 to stably contact the heat pipe 150. To allow this flexure to occur, for example, the thickness of the auxiliary shield 180 may be made smaller than the thickness of the upper board shield 130, or the auxiliary shield 180 may be formed from a material (e.g., aluminum) that is softer than the material (e.g., iron) of the lower board shield 40. This ensures sufficient stability of contact between the auxiliary shield 180 and the upper board shield 130 at the contact portion 183 and the protrusion 186, and between the auxiliary shield 180 and the heat pipe 150 at the protrusion 185, thereby improving noise blocking performance at the positions of the contact portion 183 and the protrusions 185, 186.

[0064] The distance d4 (see FIG. 11) between the fixing portion 182 and the protrusion 185 formed on the front side of the auxiliary shield 180, and the distance d5 (see FIG. 11) between the fixing portion 182 and the protrusion 186 formed on the rear side of the auxiliary shield 180, are desirably determined based on the wavelength of noise whose leakage to the outside of the upper board shield 130 is to be suppressed. The distances d4 and d5 may be set to less than one-third, and more preferably less than one-quarter, of the wavelength of the noise to be shielded. For example, by setting the distances d4 and d5 to 20 mm or less, leakage of noise in the frequency band used in wireless communication, etc. can be effectively suppressed. More preferably, the distances d4 and d5 may be set to 15 mm or less. Even more preferably, the distance d1 may be set to 10 mm or less.

[0065] As shown in Fig. 12, a conductive elastic member 190 is disposed above the upper board shield 130. As shown in Fig. 15, the elastic member 190 is disposed between the upper board shield 130 and the heat pipe 150. In the example shown in Fig. 15, the elastic member 190 is pressed in the vertical direction by the upper board shield 130 and the heat pipe 150, and the reaction force presses the heat pipe 150 against the lower surface (rear surface) of the auxiliary shield 180. This more reliably ensures contact stability between the convex portion 185 protruding downward from the lower surface of the auxiliary shield 180 and the heat pipe 150, and further improves noise blocking performance at the position of the convex portion 185.

[0066] As described above, in this embodiment as well, the heat pipe 150 passes through the opening 132 formed in the upper board shield 130 and extends to the outside of the upper circuit board shield 130. The auxiliary shield 180 is attached to the upper board shield 130 and covers the opening 132 formed in the upper board shield 130. In this way, it is possible to prevent noise from leaking from the opening 132 to the outside of the upper board shield 130.

Claims

1. A circuit board; a circuit board shield covering the circuit board; a heat pipe disposed between the circuit board and the circuit board shield; An auxiliary shield; and an opening formed in the circuit board shield; the heat pipe extends from the space between the circuit board and the circuit board shield through the opening to the outside of the circuit board shield; the auxiliary shield is attached to the circuit board shield and covers the opening; The auxiliary shield has at least one fixing portion fixed to the circuit board shield by a fixing device, and at least one contact portion located on at least one side of the heat pipe, the contact portion being spaced apart from the at least one fixing portion in the extension direction of the heat pipe and being in contact with the circuit board shield via a first protrusion. electronic equipment.

2. A circuit board; a circuit board shield covering the circuit board; a heat pipe disposed between the circuit board and the circuit board shield; An auxiliary shield; and an opening formed in the circuit board shield; the heat pipe extends from the space between the circuit board and the circuit board shield through the opening to the outside of the circuit board shield; the auxiliary shield is attached to the circuit board shield and covers the opening; the heat pipe extends in a first direction from a space between the circuit board and the circuit board shield through the opening toward an outside of the circuit board shield; the auxiliary shield has a first overlapping portion located in the first direction from the opening and covering the heat pipe, and a second overlapping portion located in a direction opposite to the first direction from the opening and covering the heat pipe, The width of the first overlapping portion in the first direction is greater than the width of the second overlapping portion in the first direction. electronic equipment.

3. A circuit board, a circuit board shield covering the circuit board; a heat pipe disposed between the circuit board and the circuit board shield; An auxiliary shield; and an opening formed in the circuit board shield; the heat pipe extends from the space between the circuit board and the circuit board shield through the opening to the outside of the circuit board shield; the auxiliary shield is attached to the circuit board shield and covers the opening; One of the auxiliary shield and the heat pipe has a second protrusion that contacts the other. electronic equipment.

4. A circuit board; a circuit board shield covering the circuit board; a heat pipe disposed between the circuit board and the circuit board shield; An auxiliary shield; and an opening formed in the circuit board shield; the heat pipe extends from the space between the circuit board and the circuit board shield through the opening to the outside of the circuit board shield; the auxiliary shield is attached to the circuit board shield and covers the opening; One of the auxiliary shield and the circuit board shield has a third protrusion that is spaced from the opening in the extension direction of the heat pipe and that contacts the other. electronic equipment.

5. The auxiliary shield has the at least one fixing portion and the at least one contact portion on both sides of the heat pipe. The electronic device according to claim 1 .

6. the auxiliary shield has two fixing portions as the at least one fixing portion, The at least one contact portion is formed between the two fixed portions. The electronic device according to claim 1 .

7. the auxiliary shield has two contact portions as the at least one contact portion, The at least one fixing portion is formed between the two contact portions. The electronic device according to claim 1 .

8. The distance between the at least one fixing portion and the at least one contact portion is less than one-third of the wavelength of the noise that the auxiliary shield shields. The electronic device according to claim 1 .

9. the auxiliary shield has at least one fixing portion fixed to the circuit board shield by a fixing device; The distance between the at least one fixing portion and the second protrusion is less than one-third of the wavelength of the noise that the auxiliary shield shields.

4. The electronic device according to claim 3.

10. the auxiliary shield has at least one fixing portion fixed to the circuit board shield by a fixing device; The distance between the at least one fixing portion and the third protrusion is less than one-third of the wavelength of the noise that the auxiliary shield shields.

5. The electronic device according to claim 4.

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