Circuit board unit, and electronic apparatus

Abstract

To provide a circuit board unit that suitably prevents unnecessary radiation noise resulting from a current flowing in a connector unit.SOLUTION: A circuit board unit 60 comprises: a first circuit board 61; a second circuit board 62; a connector unit 70 that has a first connector 71 attached to the first circuit board 61 and a second connector 72 attached to the second circuit board 62; and a metal member 80 that connects the first circuit board 61 and the second circuit board 62 to each other. The metal member 80 has a first connection part 85a that is electrically connected to a first ground layer 61g, a second connection part 85b that is electrically connected to a second ground layer 62g, and a cover part 80a that covers at least part of the connector unit 70. The cover part 80a has an opposite wall part 61. The opposite wall part 81 overlaps the first circuit board 61 when seen in a direction orthogonal to a plate surface of the first circuit board 61, and overlaps the second circuit board 62 when seen in a direction orthogonal to a plate surface of the second circuit board 62.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a circuit board unit and an electronic device. [Background technology]

[0002] For example, a board connection structure for connecting printed circuit boards, as described in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-222405 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned board connection structure, when a signal such as a high-frequency signal flows from one printed circuit board to the other printed circuit board, unwanted radiation noise, i.e., electromagnetic noise, is likely to occur, and it has been desired to suppress the unwanted radiation noise. In the board connection structure of Patent Document 1, in order to suppress the electrostatic discharge noise applied from the external connector to one printed circuit board from flowing to the board-to-board connector, a conductive member is provided to connect a portion of the ground layer located at the periphery of one printed circuit board, which is away from the board-to-board connector, to the ground layer of the other printed circuit board. However, the measure of providing such a conductive member has a problem in that it is not possible to suppress the unwanted radiation noise generated by the signal flowing through the board-to-board connector. [Means for solving the problem]

[0005] One embodiment of the circuit board unit disclosed herein comprises a first circuit board having a first ground layer, a second circuit board having a second ground layer, a connector unit having a first connector attached to the first circuit board and a second connector attached to the second circuit board, and a metal member connecting the first circuit board and the second circuit board, wherein the metal member has a first connection portion electrically connected to the first ground layer, a second connection portion electrically connected to the second ground layer, and a cover portion covering at least a portion of the connector unit, wherein the cover portion has an opposing wall portion, at least a portion of which faces the connector unit in a direction perpendicular to the plate surface of the first circuit board, and the opposing wall portion overlaps with the first circuit board when viewed in the direction perpendicular to the plate surface of the first circuit board, and overlaps with the second circuit board when viewed in the direction perpendicular to the plate surface of the second circuit board.

[0006] One aspect of an electronic device according to the present disclosure is characterized by including the circuit board unit described above. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram showing a projector according to a first embodiment. [Diagram 2] FIG. 2 is a perspective view showing a part of the circuit board unit according to the first embodiment. [Diagram 3] FIG. 2 is a plan view showing a portion of the circuit board unit according to the first embodiment. [Figure 4] 4 is a cross-sectional view showing a part of the circuit board unit of the first embodiment, taken along line IV-IV in FIG. 3. FIG. [Diagram 5] 4 is a cross-sectional view showing a part of the circuit board unit of the first embodiment, taken along line VV in FIG. 3; FIG. [Figure 6] FIG. 2 is a perspective view showing a part of the metal member of the first embodiment. [Figure 7] FIG. 6 is a cross-sectional view showing a metal member according to a second embodiment. [Figure 8] FIG. 11 is a perspective view showing a portion of a circuit board unit according to a third embodiment. [Figure 9] FIG. 11 is a cross-sectional view showing a part of a circuit board unit according to a third embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing a part of a circuit board unit according to a fourth embodiment. [Figure 11] FIG. 13 is a perspective view showing a part of a circuit board unit according to a fifth embodiment. [Figure 12] FIG. 13 is a plan view showing a portion of a circuit board unit according to a fifth embodiment. [Figure 13] 13 is a cross-sectional view showing a part of the circuit board unit according to the fifth embodiment, taken along the line XIII-XIII in FIG. 12. [Figure 14] FIG. 13 is a perspective view showing a portion of a circuit board unit according to a sixth embodiment. [Figure 15] FIG. 13 is a cross-sectional view showing a portion of a circuit board unit according to a sixth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, a projector will be described as an example of an electronic device. The scope of the present disclosure is not limited to the following embodiments, and can be arbitrarily modified within the scope of the technical ideas of the present disclosure. In addition, in the following drawings, the scale and number of each structure may be different from the actual structure in order to make each configuration easier to understand.

[0009] First Embodiment FIG. 1 is a schematic configuration diagram showing a projector 1 as an electronic device of the present embodiment. The projector 1 of this embodiment is a projection type image display device that projects a color image on a screen SCR. As shown in Fig. 1, the projector 1 includes a light source device 2, a uniform illumination optical system 40, a color separation optical system 3, a light modulation device 4R, a light modulation device 4G, a light modulation device 4B, a synthesis optical system 5, a projection optical device 6, and a control device 50. The light source device 2 emits illumination light WL toward the uniform illumination optical system 40.

[0010] The uniform illumination optical system 40 includes an integrator optical system 31, a polarization conversion element 32, and a superposition optical system 33. The integrator optical system 31 includes a first lens array 31a and a second lens array 31b. The uniform illumination optical system 40 homogenizes the intensity distribution of the illumination light WL emitted from the light source device 2 in each of the light modulation devices 4R, 4G, and 4B, which are the illuminated regions. The illumination light WL emitted from the uniform illumination optical system 40 enters the color separation optical system 3.

[0011] The color separation optical system 3 separates the white illumination light WL into red light LR, green light LG, and blue light LB. The color separation optical system 3 includes a first dichroic mirror 7a, a second dichroic mirror 7b, a first reflecting mirror 8a, a second reflecting mirror 8b, a third reflecting mirror 8c, a first relay lens 9a, and a second relay lens 9b.

[0012] The first dichroic mirror 7a separates the illumination light WL from the light source device 2 into red light LR and other light, i.e., green light LG and blue light LB. The first dichroic mirror 7a transmits the separated red light LR and reflects the other light, i.e., green light LG and blue light LB. On the other hand, the second dichroic mirror 7b separates the other light into green light LG and blue light LB. The second dichroic mirror 7b reflects the separated green light LG and transmits the blue light LB.

[0013] The first reflecting mirror 8a is disposed in the optical path of the red light LR and reflects the red light LR transmitted through the first dichroic mirror 7a toward the optical modulation device 4R. On the other hand, the second reflecting mirror 8b and the third reflecting mirror 8c are disposed in the optical path of the blue light LB and reflect the blue light LB transmitted through the second dichroic mirror 7b toward the optical modulation device 4B. In addition, the green light LG is reflected by the second dichroic mirror 7b toward the optical modulation device 4G.

[0014] The first relay lens 9a and the second relay lens 9b are disposed on the light exit side of the second dichroic mirror 7b in the optical path of the blue light LB. The first relay lens 9a and the second relay lens 9b correct a difference in illumination distribution of the blue light LB caused by the optical path length of the blue light LB being longer than the optical path length of the red light LR and the optical path length of the green light LG.

[0015] The light modulation device 4R modulates the red light LR according to image information to form image light corresponding to the red light LR. The light modulation device 4G modulates the green light LG according to image information to form image light corresponding to the green light LG. The light modulation device 4B modulates the blue light LB according to image information to form image light corresponding to the blue light LB.

[0016] For example, a transmissive liquid crystal panel is used for the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B. Furthermore, a polarizing plate (not shown) is arranged on the entrance side and the exit side of each liquid crystal panel, and is configured to pass only linearly polarized light in a specific direction.

[0017] Field lenses 10R, 10G, and 10B are disposed on the incident sides of the optical modulation device 4R, the optical modulation device 4G, and the optical modulation device 4B, respectively. The field lenses 10R, 10G, and 10B collimate the main rays of the red light LR, the green light LG, and the blue light LB incident on the optical modulation device 4R, the optical modulation device 4G, and the optical modulation device 4B, respectively.

[0018] The combining optical system 5 receives the image light emitted from the light modulation device 4R, the light modulation device 4G, and the light modulation device 4B, combines the image light corresponding to the red light LR, the green light LG, and the blue light LB, and emits the combined image light toward the projection optical device 6. The combining optical system 5 may be, for example, a cross dichroic prism.

[0019] The projection optical device 6 is composed of a plurality of projection lenses. The projection optical device 6 enlarges and projects the image light combined by the combining optical system 5 onto the screen SCR. As a result, an image is displayed on the screen SCR.

[0020] Next, the control device 50 will be described. Fig. 2 is a perspective view showing a part of a circuit board unit 60 in the control device 50. Fig. 3 is a plan view showing a part of the circuit board unit 60. Fig. 4 is a cross-sectional view showing a part of the circuit board unit 60, taken along line IV-IV in Fig. 3. Note that Fig. 4 does not show a cross-section of a connector unit 70, which will be described later. Fig. 5 is a cross-sectional view showing a part of the circuit board unit 60, taken along line VV in Fig. 3. Fig. 6 is a perspective view showing a part of a metal member 80, which will be described later.

[0021] In each figure, the X-axis, Y-axis, and Z-axis are shown as appropriate. The direction parallel to the X-axis is called the "first horizontal direction X", the direction parallel to the Y-axis is called the "second horizontal direction Y", and the direction parallel to the Z-axis is called the "upper-lower direction Z". The first horizontal direction X, the second horizontal direction Y, and the upper-lower direction Z are perpendicular to each other. The side of the upper-lower direction Z toward which the arrow of the Z-axis faces, i.e., the +Z side, is called the "upper side", and the opposite side of the upper-lower direction Z toward which the arrow of the Z-axis faces, i.e., the -Z side, is called the "lower side". The side of the first horizontal direction X toward which the arrow of the X-axis faces, i.e., the +X side, is called the "first horizontal direction one side", and the opposite side of the first horizontal direction X toward which the arrow of the X-axis faces, i.e., the -X side, is called the "first horizontal direction other side". The side of the second horizontal direction Y toward which the Y-axis arrow points, i.e., the +Y side, is referred to as the "one side of the second horizontal direction," and the side of the second horizontal direction Y opposite to the side toward which the Y-axis arrow points, i.e., the -Y side, is referred to as the "other side of the second horizontal direction."

[0022] Note that the vertical direction Z, the first horizontal direction X, and the second horizontal direction Y are names used simply to explain the relative positional relationships of each part, and the actual positional relationships may differ from those indicated by these names.

[0023] The control device 50 is a main board that controls each part of the projector 1 including the light source device 2. As shown in FIG. 2 to FIG. 5, the control device 50 has a circuit board unit 60. As shown in FIG. 2, the circuit board unit 60 includes a first circuit board 61, a second circuit board 62, and a connector unit 70. The first circuit board 61 and the second circuit board 62 are electrically connected to each other via the connector unit 70. In this embodiment, the first circuit board 61 and the second circuit board 62 are plate-shaped with their plate surfaces facing the up-down direction Z, and extend along the first horizontal direction X and the second horizontal direction Y. The plate surfaces of the first circuit board 61 and the second circuit board 62 are perpendicular to the up-down direction Z.

[0024] In this embodiment, the vertical direction Z corresponds to a "first direction" perpendicular to the plate surface of the first circuit board 61, the second horizontal direction Y corresponds to a "second direction" perpendicular to the first direction, and the first horizontal direction X corresponds to a "third direction" perpendicular to both the first direction and the second direction.

[0025] In this embodiment, the plate surface of the first circuit board 61 and the plate surface of the second circuit board 62 are parallel to each other. In this specification, "certain objects are parallel to each other" includes cases where certain objects are approximately parallel to each other, in addition to cases where certain objects are strictly parallel to each other. Cases where certain objects are approximately parallel to each other include, for example, cases where one object is inclined relative to the other object by about 15° or less.

[0026] 3, in this embodiment, the first circuit board 61 and the second circuit board 62 are arranged side by side in a direction along the plate surfaces of the first circuit board 61 and the second circuit board 62. In this embodiment, the first circuit board 61 and the second circuit board 62 are arranged side by side in the second horizontal direction Y. The first circuit board 61 and the second circuit board 62 are arranged apart from each other in the second horizontal direction Y. In this embodiment, the first circuit board 61 and the second circuit board 62 are arranged at the same position in the up-down direction Z.

[0027] In this embodiment, the first circuit board 61 and the second circuit board 62 are printed circuit boards provided with wiring patterns made of copper foil. The first circuit board 61 and the second circuit board 62 are boards having the same type of structure. In the following description, the description of the second circuit board 62, which has the same configuration as the first circuit board 61, may be partially omitted.

[0028] As shown in FIG. 4, the first circuit board 61 has first insulating layers 61a and 61b, a first wiring layer 61c, and a first ground layer 61g. The first insulating layer 61a is laminated on the upper side of the first ground layer 61g. The first insulating layer 61b is laminated on the lower side of the first ground layer 61g. The first wiring layer 61c is laminated on the upper side of the first insulating layer 61a. The first wiring layer 61c is a layer formed of a plurality of wiring patterns made of copper foil. The first wiring layer 61c has a signal line 61d electrically connected to the first connector 71. As shown in FIG. 3, the signal line 61d extends in the second horizontal direction Y. A plurality of signal lines 61d are provided side by side in the first horizontal direction X. The plurality of signal lines 61d includes a signal line 61d through which a high-frequency signal flows. The high-frequency signal is, for example, a signal of 20 MHz or more. In FIG. 3, only some of the signal lines 61d are shown.

[0029] Although not shown in the figures, the first wiring layer 61c is covered with a resist layer, for example, except for a portion to which an electronic element mounted on the upper surface of the first circuit board 61 is electrically connected. The upper surface of the first wiring layer 61c, the upper surface of the resist layer, and first ground pad portions 61i and 61j described below form the upper surface of the first circuit board 61. In this embodiment, the upper surface of the first circuit board 61 is the upper plate surface of the first circuit board 61 and is a mounting surface on which electronic elements and the like are attached.

[0030] 4, in this embodiment, the first ground layer 61g is an inner layer that constitutes a part of the first circuit board 61. The first ground layer 61g is a layer whose potential serves as a reference potential in the circuit board unit 60. The first ground layer 61g is formed of, for example, a solid pattern made of copper foil. The first ground layer 61g is also called a reference plane.

[0031] As shown in FIG. 3, a pair of first ground pad portions 61i, 61j are formed on the upper surface of the first circuit board 61. The pair of first ground pad portions 61i, 61j are provided with a gap in the first horizontal direction X. The first ground pad portion 61i is located on one side in the first horizontal direction, i.e., on the +X side, of the first ground pad portion 61j. In this embodiment, each of the first ground pad portions 61i, 61j has a rectangular shape when viewed in the up-down direction Z. As shown in FIG. 5, in this embodiment, the first ground pad portion 61i is provided in the same layer as the first wiring layer 61c, and is electrically connected to the first ground layer 61g through a via 61v formed in the first insulating layer 61a. Although not shown, the first ground pad portion 61j is also electrically connected to the first ground layer 61g in the same manner as the first ground pad portion 61i. The pair of first ground pad portions 61i, 61j may be a portion of the first ground layer 61g exposed on the upper surface of the first circuit board 61 through an opening formed in the first insulating layer 61a.

[0032] The second circuit board 62 is disposed on one side of the first circuit board 61 in the second horizontal direction, that is, on the +Y side, with a gap therebetween. As shown in FIG. 4, the second circuit board 62 has second insulating layers 62a and 62b, a second wiring layer 62c, and a second ground layer 62g. The second insulating layers 62a and 62b, the second wiring layer 62c, and the second ground layer 62g are layers similar to the first insulating layers 61a and 61b, the first wiring layer 61c, and the first ground layer 61g in the first circuit board 61, respectively. The second wiring layer 62c has a signal line 62d electrically connected to the second connector 72. As shown in FIG. 3, the signal line 62d extends in the second horizontal direction Y. A plurality of signal lines 62d are provided side by side in the first horizontal direction X. The plurality of signal lines 62d includes a signal line 62d through which a high-frequency signal flows. The high-frequency signal is, for example, a signal of 20 MHz or higher. Note that only some of the signal lines 62d are shown in FIG.

[0033] As shown in FIG. 3, a pair of second ground pad portions 62i, 62j are formed on the upper surface of the second circuit board 62. The pair of second ground pad portions 62i, 62j are provided at an interval in the first horizontal direction X. The pair of second ground pad portions 62i, 62j are similar to the pair of first ground pad portions 61i, 61j. Each of the pair of first ground pad portions 61i, 61j and each of the pair of second ground pad portions 62i, 62j are arranged side by side at an interval in the second horizontal direction Y. As shown in FIG. 5, the second ground pad portion 62i is provided in the same layer as the second wiring layer 62c, and is electrically connected to the second ground layer 62g through a via 62v formed in the second insulating layer 62a. Although not shown, the second ground pad portion 62j is also electrically connected to the second ground layer 62g in the same manner as the second ground pad portion 62i. The pair of second ground pad portions 62i, 62j may be a portion of the second ground layer 62g exposed on the upper surface of the second circuit board 62 through an opening formed in the second insulating layer 62a.

[0034] The connector unit 70 relays signal transmission between the first circuit board 61 and the second circuit board 62. As shown in Fig. 3, in this embodiment, the connector unit 70 has a generally rectangular shape that is long in the first horizontal direction X when viewed in the up-down direction Z. Note that Fig. 2 shows the connector unit 70 in a schematic manner, with first connectors 71b and second connectors 72b, which will be described later, omitted from illustration.

[0035] 4, the connector unit 70 has a first connector 71 and a second connector 72. The first connector 71 is attached to the upper surface of the first circuit board 61. The second connector 72 is attached to the upper surface of the second circuit board 62. The first connector 71 and the second connector 72 are connected in the second horizontal direction Y. That is, in this embodiment, the connection direction between the first connector 71 and the second connector 72 is the second horizontal direction Y.

[0036] In this embodiment, the first connector 71 is a female connector, and the second connector 72 is a male connector. The first connector 71 and the second connector 72 are fitted together in the second horizontal direction Y and electrically connected to each other. That is, in this embodiment, the fitting direction of the first connector 71 and the second connector 72 is the second horizontal direction Y.

[0037] The first connector 71 has a first housing 71a and a plurality of first connectors 71b. The first housing 71a is a resin member that holds the plurality of first connectors 71b. The first housing 71a is made by insert molding using the plurality of first connectors 71b as an insert member, for example. The first housing 71a is substantially rectangular box-shaped. The first housing 71a is in contact with the upper surface of the first circuit board 61. The first housing 71a may be disposed above the upper surface of the first circuit board 61 with a gap therebetween. The first housing 71a protrudes from the first circuit board 61 to one side in the second horizontal direction, i.e., the +Y side. The first housing 71a is a holder that holds the plurality of first connectors 71b.

[0038] The first connectors 71b are held by the first housing 71a. A portion of each of the first connectors 71b is embedded in the first housing 71a. The first connectors 71b are made of metal and are slender plate-like members. As shown in FIG. 3, the first connectors 71b are arranged side by side at intervals in the first horizontal direction X. As shown in FIG. 4, the first connectors 71b have a first extension portion 71c, a second extension portion 71d, and a board connection portion 71e.

[0039] The first extension portion 71c extends in the second horizontal direction Y. An end portion of the first extension portion 71c on one side in the second horizontal direction, i.e., the +Y side, is exposed in a recess (not shown) that is formed in the first housing 71a and opens to one side in the second horizontal direction. An end portion of the first extension portion 71c on the other side in the second horizontal direction, i.e., the -Y side, protrudes from the first housing 71a to the other side in the second horizontal direction and is exposed from the first housing 71a. As a result, the first connector 71b of the first connector 71 protrudes from the first housing 71a in the second horizontal direction Y.

[0040] The second extension portion 71d extends downward and obliquely toward the other side in the second horizontal direction from the end of the first extension portion 71c on the other side in the second horizontal direction, i.e., the -Y side. The board connection portion 71e extends from the lower end of the second extension portion 71d toward the other side in the second horizontal direction. The board connection portion 71e is electrically connected to the first circuit board 61. As a result, the first connector 71b is electrically connected to the first circuit board 61. As shown in FIG. 3, the board connection portions 71e of the multiple first connectors 71b are electrically connected to the multiple signal lines 61d, respectively. More specifically, the board connection portion 71e contacts the portion of the signal line 61d exposed on the upper surface of the first circuit board 61, and is electrically connected to the signal line 61d.

[0041] As shown in FIG. 4, the second connector 72 is located on one side of the first connector 71 in the second horizontal direction, that is, on the +Y side. The second connector 72 has a second housing 72a and a plurality of second connectors 72b. The second housing 72a is a resin member that holds the plurality of second connectors 72b. The second housing 72a is made by insert molding using the plurality of second connectors 72b as an insert member, for example. The second housing 72a is in the shape of a substantially rectangular box. The second housing 72a is in contact with the upper surface of the second circuit board 62. The second housing 72a may be disposed above the upper surface of the second circuit board 62 with a gap therebetween. The second housing 72a protrudes further toward the other side of the second horizontal direction, that is, toward the -Y side, than the second circuit board 62. The second housing 72a is a holder that holds the plurality of second connectors 72b.

[0042] The second connectors 72b are held by the second housing 72a. A portion of each of the second connectors 72b is embedded in the second housing 72a. The second connectors 72b are made of metal and are elongated plate-like members. As shown in FIG. 3, the second connectors 72b are arranged side by side at intervals in the first horizontal direction X. Each of the second connectors 72b is arranged side by side on one side in the second horizontal direction, i.e., on the +Y side, with respect to each of the first connectors 71b.

[0043] As shown in FIG. 4, the second connector 72b has a first extension 72c, a second extension 72d, and a board connection 72e. The first extension 72c extends in the second horizontal direction Y. The end of the first extension 72c on the other side in the second horizontal direction is inserted into a recess (not shown) formed in the first housing 71a and contacts the first extension 71c of the first connector 71b exposed in the recess. This electrically connects the first connector 71b and the second connector 72b to each other. The end of the first extension 72c on one side in the second horizontal direction, i.e., the +Y side, protrudes from the second housing 72a to one side in the second horizontal direction and is exposed from the second housing 72a. This allows the second connector 72b of the second connector 72 to protrude from the second housing 72a in the second horizontal direction Y.

[0044] The second extending portion 72d extends downward and diagonally toward one side in the second horizontal direction from the end of the first extending portion 72c on one side in the second horizontal direction, i.e., the +Y side. The board connecting portion 72e extends from the lower end of the second extending portion 72d toward one side in the second horizontal direction. The board connecting portion 72e is electrically connected to the second circuit board 62. As a result, the second connectors 72b are electrically connected to the second circuit board 62. As shown in FIG. 3, the board connecting portions 72e of the multiple second connectors 72b are electrically connected to the multiple signal lines 62d, respectively. More specifically, the board connecting portion 72e contacts the portion of the signal line 62d exposed on the upper surface of the second circuit board 62, and is electrically connected to the signal line 62d.

[0045] The circuit board unit 60 includes a metal member 80 that connects the first circuit board 61 and the second circuit board 62. The metal member 80 electrically connects the first ground layer 61g and the second ground layer 62g. As shown in FIG. 2 and FIG. 6, in this embodiment, the metal member 80 is a sheet metal member. The metal member 80 is made by subjecting a sheet metal to a press process. There is no particular limitation on the material that constitutes the metal member 80, so long as it is a metal. Instead of the metal member 80, a conductive member such as carbon may be used.

[0046] As shown in FIG. 2, the metal member 80 has a cover portion 80a and a pair of fixing portions 82a, 82b. The cover portion 80a is a portion that covers at least a part of the connector unit 70. In this embodiment, the cover portion 80a is a substantially rectangular box shape that opens downward. The cover portion 80a covers the connector unit 70 from above. The cover portion 80a covers the connector unit 70 from the upper side, both sides in the first horizontal direction X, and both sides in the second horizontal direction Y. The cover portion 80a covers at least a part of the gap in the second horizontal direction Y between the first circuit board 61 and the second circuit board 62 from the upper side. The cover portion 80a has an opposing wall portion 81, a protruding wall portion 83, a connecting wall portion 84, and bent portions 83c, 83d.

[0047] The opposing wall portion 81 is a plate-like member with a plate surface facing the up-down direction Z. The plate surface of the opposing wall portion 81 is perpendicular to the up-down direction Z. In this embodiment, the opposing wall portion 81 is a substantially rectangular plate-like member that is long in the first horizontal direction X. The opposing wall portion 81 is located above the connector unit 70. At least a part of the opposing wall portion 81 faces the connector unit 70 in a direction perpendicular to the plate surface of the first circuit board 61, that is, in the up-down direction Z. In this embodiment, almost the entire opposing wall portion 81 faces the connector unit 70 in the up-down direction Z, except for both edges in the first horizontal direction X and both edges in the second horizontal direction Y. The opposing wall portion 81 has a portion facing the first connector 71 in the up-down direction Z and a portion facing the second connector 72 in the up-down direction Z. The opposing wall portion 81 faces the first housing 71a, the first connector 71b, the second housing 72a, and the second connector 72b in the up-down direction Z.

[0048] The facing wall 81 covers at least a part of the connector unit 70 from above. In this embodiment, the facing wall 81 has a portion that covers the first connector 71 from above and a portion that covers the second connector 72 from above. In this embodiment, the facing wall 81 covers the entire connector unit 70 from above. The facing wall 81 overlaps the connector unit 70 when viewed in the up-down direction Z, and further has a portion that overlaps the first circuit board 61 and a portion that overlaps the second circuit board 62. In other words, the facing wall 81 overlaps the first circuit board 61 when viewed in a direction perpendicular to the plate surface of the first circuit board 61, and overlaps the second circuit board 62 when viewed in a direction perpendicular to the plate surface of the second circuit board 62. The edge of the facing wall 81 on the other side of the second horizontal direction, i.e., the -Y side, is located above the first circuit board 61. One edge of the opposing wall portion 81 in the second horizontal direction, that is, the +Y side, is located above the second circuit board 62.

[0049] 4, the end of the opposing wall 81 on the other side in the second horizontal direction, i.e., the -Y side, is located further to the other side in the second horizontal direction than the end of the first connector 71b on the other side in the second horizontal direction. In other words, the end of the opposing wall 81 on the side where the first connector 71b protrudes relative to the first housing 71a, i.e., the -Y side, is located outside the end of the first connector 71b on the side where the first connector 71b protrudes relative to the first housing 71a. In this embodiment, the end of the first connector 71b on the other side in the second horizontal direction is the end of the board connection portion 71e on the other side in the second horizontal direction.

[0050] The end of the opposing wall 81 on one side in the second horizontal direction, i.e., the +Y side, is located further to the one side in the second horizontal direction than the end of the second connector 72b on one side in the second horizontal direction. In other words, the end of the opposing wall 81 on the side where the second connector 72b protrudes relative to the second housing 72a, i.e., the +Y side, is located outside the end of the second connector 72b on the side where the second connector 72b protrudes relative to the second housing 72a. In this embodiment, the end of the second connector 72b on one side in the second horizontal direction is the end of the board connection portion 72e on one side in the second horizontal direction.

[0051] The shortest distance in the up-down direction Z between the opposing wall portion 81 and the connector unit 70 is, for example, smaller than the dimension of the connector unit 70 in the up-down direction Z. The dimension of the connector unit 70 in the up-down direction Z is, for example, equal to each of the dimension of the first connector 71 in the up-down direction Z and the dimension of the second connector 72 in the up-down direction Z. The shortest distance in the up-down direction Z between the opposing wall portion 81 and the connector unit 70 is, for example, smaller than the distance in the second horizontal direction Y between the first circuit board 61 and the second circuit board 62. The shortest distance in the up-down direction Z between the opposing wall portion 81 and the connector unit 70 is, for example, about 0.5 mm or more and 20 mm or less. It is preferable that the shortest distance in the up-down direction Z between the opposing wall portion 81 and the connector unit 70 is, for example, smaller than 10 mm. In this embodiment, the shortest distance in the vertical direction Z between the opposing wall portion 81 and the connector unit 70 is the distance in the vertical direction Z between the lower surface of the opposing wall portion 81 and the upper surface of the first housing 71a and the distance in the vertical direction Z between the lower surface of the opposing wall portion 81 and the upper surface of the second housing 72a.

[0052] The protruding wall portion 83 protrudes from the opposing wall portion 81 toward one of the first circuit board 61 and the second circuit board 62. In this embodiment, the protruding wall portion 83 is plate-shaped with a plate surface facing the second horizontal direction Y. The plate surface of the protruding wall portion 83 is perpendicular to the second horizontal direction Y. As shown in FIG. 2, in this embodiment, the protruding wall portion 83 is a substantially rectangular plate-shaped portion that is long in the first horizontal direction X. The dimension of the protruding wall portion 83 in the first horizontal direction X is smaller than the dimension of the opposing wall portion 81 in the first horizontal direction X. In this embodiment, the protruding wall portion 83 is a portion bent in the up-down direction Z from an edge of the opposing wall portion 81 in the second horizontal direction Y.

[0053] In this embodiment, the protruding wall portion 83 is provided as a pair of a protruding wall portion (first protruding wall portion) 83a and a protruding wall portion (second protruding wall portion) 83b. The protruding wall portion 83a protrudes downward from the edge of the opposing wall portion 81 on the other side in the second horizontal direction, i.e., the -Y side, toward the first circuit board 61. The protruding wall portion 83b protrudes downward from the edge of the opposing wall portion 81 on one side in the second horizontal direction, i.e., the +Y side, toward the second circuit board 62. As shown in FIG. 4, the pair of protruding walls 83a, 83b are provided to sandwich the connector unit 70 in the second horizontal direction Y. The pair of protruding walls 83a, 83b face the connector unit 70 in the second horizontal direction Y. The protruding wall portion 83a is located away from the other side in the second horizontal direction of the first connector 71 and faces the first connector 71 with a gap therebetween. The protruding wall portion 83a covers at least a portion of the first connector 71 from the other side in the second horizontal direction. In this embodiment, the protruding wall portion 83a covers almost the entire first connector 71 except for its lower end portion from the other side in the second horizontal direction. The protruding wall portion 83b is located away from the second connector 72 on one side in the second horizontal direction and faces the second connector 72 with a gap therebetween. The protruding wall portion 83b covers at least a portion of the second connector 72 from one side in the second horizontal direction. In this embodiment, the protruding wall portion 83b covers almost the entire second connector 72 except for its lower end portion from one side in the second horizontal direction.

[0054] In this embodiment, a gap is provided between the protruding wall portion 83a and the first circuit board 61. That is, the lower end of the protruding wall portion 83a is located above and away from the upper surface of the first circuit board 61. The lower end of the protruding wall portion 83a is located below the first extending portion 71c. In this embodiment, a gap is provided between the protruding wall portion 83b and the second circuit board 62. That is, the lower end of the protruding wall portion 83b is located above and away from the upper surface of the second circuit board 62. The lower end of the protruding wall portion 83b is located below the first extending portion 72c. The protruding wall portion 83a is located above the signal line 61d. The protruding wall portion 83b is located above the signal line 62d.

[0055] The shortest distance in the second horizontal direction Y between the protruding wall portion 83a and the first housing 71a is, for example, smaller than the dimension of the first housing 71a in the second horizontal direction Y. The shortest distance in the second horizontal direction Y between the protruding wall portion 83a and the first housing 71a is larger than the shortest distance in the up-down direction Z between the opposing wall portion 81 and the connector unit 70. The shortest distance in the second horizontal direction Y between the protruding wall portion 83a and the first housing 71a is, for example, about 0.5 mm or more and 20 mm or less. It is preferable that the shortest distance in the second horizontal direction Y between the protruding wall portion 83a and the first housing 71a is, for example, smaller than 10 mm. The shortest distance in the second horizontal direction Y between the protruding wall portion 83b and the second housing 72a is similar to the shortest distance in the second horizontal direction Y between the protruding wall portion 83a and the first housing 71a. The shortest distance in the second horizontal direction Y between the protruding wall portion 83b and the second housing 72a is, for example, smaller than the dimension in the second horizontal direction Y of the second housing 72a.

[0056] The dimension of the gap between the protruding wall portion 83a and the first circuit board 61 in the vertical direction Z is smaller than the plate thickness of the first circuit board 61, i.e., the dimension of the first circuit board 61 in the vertical direction Z. The dimension of the gap between the protruding wall portion 83a and the first circuit board 61 in the vertical direction Z is, for example, about 0.5 mm or more and 20 mm or less. It is preferable that the dimension of the gap between the protruding wall portion 83a and the first circuit board 61 in the vertical direction Z is, for example, smaller than 10 mm. The dimension of the gap between the protruding wall portion 83b and the second circuit board 62 in the vertical direction Z is similar to the dimension of the gap between the protruding wall portion 83a and the first circuit board 61 in the vertical direction Z. The dimension of the gap between the protruding wall portion 83b and the second circuit board 62 in the vertical direction Z is smaller than the plate thickness of the second circuit board 62, i.e., the dimension of the second circuit board 62 in the vertical direction Z.

[0057] As shown in FIG. 2, the connecting wall portion 84 protrudes downward from the opposing wall portion 81. In this embodiment, the connecting wall portion 84 is plate-shaped with a plate surface facing the first horizontal direction X. The plate surface of the connecting wall portion 84 is perpendicular to the first horizontal direction X. In this embodiment, the connecting wall portion 84 is a substantially rectangular plate-shaped portion that is long in the second horizontal direction Y. The dimension of the connecting wall portion 84 in the second horizontal direction Y is smaller than the dimension of the opposing wall portion 81 in the second horizontal direction Y. In this embodiment, the connecting wall portion 84 is a portion that is bent in the up-down direction Z from an edge portion of the opposing wall portion 81 in the first horizontal direction X.

[0058] In this embodiment, the connection wall portion 84 is provided as a pair of a connection wall portion (first connection wall portion) 84a and a connection wall portion (second connection wall portion) 84b. The connection wall portion 84a protrudes downward from an edge portion of the opposing wall portion 81 on one side in the first horizontal direction, i.e., the +X side. The connection wall portion 84b protrudes downward from an edge portion of the opposing wall portion 81 on the other side in the first horizontal direction, i.e., the -Y side. The connection wall portion 84a connects the fixing portion 82a and the opposing wall portion 81. The connection wall portion 84b connects the fixing portion 82b and the opposing wall portion 81. In other words, the connection wall portion 84b is disposed on the opposite side to the connection wall portion 84a and is connected to the opposing wall portion 81.

[0059] The pair of connection walls 84a, 84b are provided to sandwich the connector unit 70 in the first horizontal direction X. The pair of connection walls 84a, 84b face the connector unit 70 in the first horizontal direction X. The connection wall 84a is located away from the first connector 71 and the second connector 72 on one side in the first horizontal direction, i.e., the +X side, and faces the first connector 71 and the second connector 72 with a gap. The connection wall 84a covers at least a part of the first connector 71 and at least a part of the second connector 72 from one side in the first horizontal direction. In this embodiment, the connection wall 84a covers the entire first connector 71 and the entire second connector 72 from one side in the first horizontal direction. The connection wall 84b is located away from the other side in the first horizontal direction, i.e., the -X side, of the first connector 71 and the second connector 72, and faces the first connector 71 and the second connector 72 with a gap. The connection wall portion 84b covers at least a part of the first connector 71 and at least a part of the second connector 72 from the other side in the first horizontal direction. In this embodiment, the connection wall portion 84b covers the entire first connector 71 and the entire second connector 72 from the other side in the first horizontal direction.

[0060] The connection wall portion 84a is located away from the protruding walls 83a and 83b on one side in the first horizontal direction, i.e., on the +X side. Between the connection wall portion 84a and the protruding walls 83a and 83b, there are provided gaps connecting the inside of the cover portion 80a to the outside of the cover portion 80a. The connection wall portion 84b is located away from the protruding walls 83a and 83b on the other side in the first horizontal direction, i.e., on the -X side. Between the connection wall portion 84b and the protruding walls 83a and 83b, there are provided gaps connecting the inside of the cover portion 80a to the outside of the cover portion 80a. The pair of connection walls 84a and 84b each extend in the second horizontal direction Y from the upper side of the first circuit board 61 to the upper side of the second circuit board 62.

[0061] The bent portions 83c and 83d are portions bent from the edge of the protruding wall portion 83 in the first horizontal direction X to the second horizontal direction Y. The bent portion 83c is bent from the edge of the protruding wall portion 83a in the first horizontal direction X to one side in the second horizontal direction, i.e., the +Y side. In this embodiment, the bent portions 83c are provided on both edges of the protruding wall portion 83a in the first horizontal direction X. The bent portion 83c located on one side in the first horizontal direction, i.e., the +X side, is inserted into the gap between the protruding wall portion 83a and the connecting wall portion 84a. The bent portion 83c located on the other side in the first horizontal direction, i.e., the -X side, is inserted into the gap between the protruding wall portion 83a and the connecting wall portion 84b. At least a part of each bent portion 83c is located between each connecting wall portion 84a, 84b and the connector unit 70 in the first horizontal direction X. In the present embodiment, a portion of the bent portion 83c on one side in the second horizontal direction is located between each of the connecting walls 84a, 84b and the first connector 71 in the first horizontal direction X. Each of the bent portions 83c may be in contact with each of the connecting walls 84a, 84b, or may be disposed with a gap between each of the connecting walls 84a, 84b.

[0062] As shown in FIG. 6, the bent portion 83d is bent from an edge of the protruding wall portion 83b in the first horizontal direction X to the other side in the second horizontal direction, i.e., the -Y side. In this embodiment, the bent portions 83d are provided on both edges of the protruding wall portion 83b in the first horizontal direction X. The pair of bent portions 83d is disposed symmetrically with the pair of bent portions 83c in the second horizontal direction Y. Each of the pair of bent portions 83c and each of the pair of bent portions 83d are disposed opposite each other with a gap in between in the second horizontal direction Y. In this embodiment, the portion of the bent portion 83d on the other side in the second horizontal direction is located between each of the connection walls 84a, 84b and the second connector 72 in the first horizontal direction X.

[0063] 2, the fixing portions 82a and 82b are portions fixed to the first circuit board 61 and the second circuit board 62. The fixing portion 82a protrudes from a lower edge of the connection wall portion 84a to one side in the first horizontal direction, i.e., the +X side. In this embodiment, the fixing portion 82a has a plate-shaped portion 85, a pair of cylindrical portions 82e and 82f, and a pair of engaging claw portions 82g and 82h.

[0064] The plate-shaped portion 85 is a plate-shaped portion connected to the connection wall portion 84a. The plate surface of the plate-shaped portion 85 is perpendicular to the up-down direction Z. In this embodiment, the plate-shaped portion 85 is a substantially rectangular plate that is long in the second horizontal direction Y. The lower end of the connection wall portion 84a is connected to the edge of the plate-shaped portion 85 on the other side of the first horizontal direction, i.e., the -X side. In this embodiment, the plate-shaped portion 85 is a portion bent in the first horizontal direction X from the lower edge of the connection wall portion 84a. The lower surface of the plate-shaped portion 85 is in contact with the first ground pad portion 61i formed on the upper surface of the first circuit board 61 and the second ground pad portion 62i formed on the upper surface of the second circuit board 62. As a result, the plate-shaped portion 85 is electrically connected to the first ground layer 61g and the second ground layer 62g via the first ground pad portion 61i and the second ground pad portion 62i.

[0065] The portion of the plate-shaped portion 85 electrically connected to the first ground pad portion 61i is a first connection portion 85a electrically connected to the first ground layer 61g via the first ground pad portion 61i. The portion of the plate-shaped portion 85 electrically connected to the second ground pad portion 62i is a second connection portion 85b electrically connected to the second ground layer 62g via the second ground pad portion 62i. In this embodiment, the first connection portion 85a is a portion of the plate-shaped portion 85 on the other side in the second horizontal direction, i.e., the -Y side. The second connection portion 85b is a portion of the plate-shaped portion 85 on one side in the second horizontal direction, i.e., the +Y side. In this embodiment, the first connection portion 85a and the second connection portion 85b are connected to each other. The first connection portion 85a and the second connection portion 85b are connected to the connection wall portion 84a. That is, in this embodiment, the connection wall portion 84a connects both the first connection portion 85a and the second connection portion 85b to the opposing wall portion 81.

[0066] The pair of cylindrical portions 82e, 82f protrude upward from the plate-like portion 85. The pair of cylindrical portions 82e, 82f are cylindrical and open upward. The pair of cylindrical portions 82e, 82f are provided with a gap between them in the second horizontal direction Y. The cylindrical portion 82e is provided in the first connection portion 85a. The cylindrical portion 82f is provided in the second connection portion 85b.

[0067] The pair of engagement claws 82g, 82h protrude downward from both edges of the plate-shaped portion 85 in the second horizontal direction Y. The engagement claw 82g protrudes downward from the edge of the plate-shaped portion 85 on the other side in the second horizontal direction, i.e., the -Y side. The engagement claw 82h protrudes downward from the edge of the plate-shaped portion 85 on one side in the second horizontal direction, i.e., the +Y side. As shown in FIG. 5, the engagement claw 82g is inserted from above into an engagement hole 61k formed in the first circuit board 61. The engagement hole 61k penetrates the first circuit board 61 in the up-down direction Z. The engagement claw 82h is inserted from above into an engagement hole 62k formed in the second circuit board 62. The engagement hole 62k penetrates the second circuit board 62 in the up-down direction Z.

[0068] A pair of female threaded holes 82i, 82j are formed in the fixing portion 82a. The female threaded hole 82i is formed in the first connecting portion 85a and penetrates the first connecting portion 85a and the cylindrical portion 82e in the up-down direction Z. The inner peripheral surface of the cylindrical portion 82e constitutes a part of the inner peripheral surface of the female threaded hole 82i. A female thread is formed in the inner peripheral surface of the female threaded hole 82i. The female threaded hole 82j is formed in the second connecting portion 85b and penetrates the second connecting portion 85b and the cylindrical portion 82f in the up-down direction Z. The inner peripheral surface of the cylindrical portion 82f constitutes a part of the inner peripheral surface of the female threaded hole 82j. A female thread is formed in the inner peripheral surface of the female threaded hole 82j.

[0069] A metal bolt 91 for fixing the first connection portion 85a to the first circuit board 61 is fastened into the female screw hole 82i. The bolt 91 is passed through a through hole 61h formed in the first circuit board 61 from below and fastened into the female screw hole 82i. The through hole 61h penetrates the first circuit board 61 in the up-down direction Z. The inner diameter of the through hole 61h is larger than the inner diameter of the female screw hole 82i. The upper end of the through hole 61h opens into the first ground pad portion 61i. The upper end of the bolt 91 protrudes upward beyond the cylindrical portion 82e. The first connection portion 85a is fixed to the first circuit board 61 by the bolt 91, so that the lower surface of the first connection portion 85a is appropriately pressed against the first ground pad portion 61i. As a result, the first connection portion 85a is suitably and electrically connected to the first ground pad portion 61i, and the first connection portion 85a is suitably and electrically connected to the first ground layer 61g.

[0070] A metal bolt 92 for fixing the second connection portion 85b to the second circuit board 62 is fastened into the female screw hole 82j. The bolt 92 is passed through a through hole 62h formed in the second circuit board 62 from below and fastened into the female screw hole 82j. The through hole 62h penetrates the second circuit board 62 in the up-down direction Z. The inner diameter of the through hole 62h is larger than the inner diameter of the female screw hole 82j. The upper end of the through hole 62h opens into the second ground pad portion 62i. The upper end of the bolt 92 protrudes upward beyond the cylindrical portion 82f. The second connection portion 85b is fixed to the second circuit board 62 by the bolt 92, so that the lower surface of the second connection portion 85b is appropriately pressed against the second ground pad portion 62i. As a result, the second connection portion 85b is suitably and electrically connected to the second ground pad portion 62i, and the second connection portion 85b is suitably and electrically connected to the second ground layer 62g.

[0071] 2, the fixed portion 82b is disposed symmetrically with respect to the fixed portion 82a in the first horizontal direction X. Like the fixed portion 82a, the fixed portion 82b has a first connection portion electrically connected to the first ground layer 61g and a second connection portion electrically connected to the second ground layer 62g. The first connection portion 85a in the fixed portion 82b is electrically connected to the first ground layer 61g via the first ground pad portion 61j. The second connection portion 85b in the fixed portion 82b is electrically connected to the second ground layer 62g via the second ground pad portion 62j.

[0072] A current Is1 flows between the first circuit board 61 and the second circuit board 62 via the connector unit 70, transmitting a signal. In the example of Fig. 4, the current Is1 flowing from the first circuit board 61 to the second circuit board 62 is indicated by a dashed arrow. The current Is1 flows from the signal line 61d formed on the first circuit board 61 through the first connector 71b and the second connector 72b in this order, and then flows to the signal line 62d formed on the second circuit board 62. When the current Is1 flows in this manner, a return current Ir1 corresponding to the current Is1 flows.

[0073] In the example of FIG. 4, the return current Ir1 indicated by the dashed arrow is a return current flowing from the second ground layer 62g of the second circuit board 62 to the first ground layer 61g of the first circuit board 61. The return current Ir1 flows in the opposite direction to the current Is1 through a portion of the second ground layer 62g located below the signal line 62d, and then flows from the second ground layer 62g to the protruding wall portion 83b. Here, in this embodiment, the second ground layer 62g and the protruding wall portion 83b are not connected by a conductor, but the return current Ir1 generated in response to the high-frequency current Is1 can propagate from the second ground layer 62g to the protruding wall portion 83b due to capacitive coupling in space. The return current Ir1 that flows through the protruding wall portion 83b flows through the opposing wall portion 81 and the protruding wall portion 83a in this order, and flows from the protruding wall portion 83a to the first ground layer 61g of the first circuit board 61. In this embodiment, the protruding wall 83a and the first ground layer 61g are not connected by a conductor either, but the return current Ir1 generated in response to the high-frequency current Is1 can propagate from the protruding wall 83a to the first ground layer 61g due to capacitive coupling in space. The return current Ir1 that has flowed into the first ground layer 61g flows in a portion of the first ground layer 61g that is located below the signal line 61d in the opposite direction to the current Is1.

[0074] In this manner, in this embodiment, a return path through which the return current Ir1 generated when the current Is1 flows through the connector unit 70 flows is formed by the metal member 80. When the current Is1 flows from the second circuit board 62 to the first circuit board 61, the return current Ir1 flows in the opposite direction to the direction of the dashed arrow shown in FIG. 4, from the first ground layer 61g to the second ground layer 62g.

[0075] According to this embodiment, the circuit board unit 60 includes a first circuit board 61 having a first ground layer 61g, a second circuit board 62 having a second ground layer 62g, a connector unit 70 having a first connector 71 attached to the first circuit board 61 and a second connector 72 attached to the second circuit board 62, and a metal member 80 connecting the first circuit board 61 and the second circuit board 62. The metal member 80 includes a first connection portion 85a electrically connected to the first ground layer 61g, a second connection portion 85b electrically connected to the second ground layer 62g, and a cover portion 80a covering at least a part of the connector unit 70. The cover portion 80a has an opposing wall portion 81, at least a part of which faces the connector unit 70 in the up-down direction Z perpendicular to the plate surface of the first circuit board 61. The opposing wall portion 81 overlaps the first circuit board 61 when viewed in the vertical direction Z perpendicular to the plate surface of the first circuit board 61, and also overlaps the second circuit board 62 when viewed in the vertical direction Z perpendicular to the plate surface of the second circuit board 62.

[0076] Therefore, while arranging the facing wall portion 81 close to the connector unit 70, the return current Ir1 can be easily propagated between the first ground layer 61g of the first circuit board 61 and the facing wall portion 81, and between the second ground layer 62g of the second circuit board 62 and the facing wall portion 81. Thereby, as described above, the metal member 80 can preferably provide a return path through which the return current Ir1 flows between the first circuit board 61 and the second circuit board 62. Therefore, the electromagnetic field generated by the return current Ir1 flowing through the metal member 80 can preferably cancel the electromagnetic field generated by the current Is1 flowing through the connector unit 70. Therefore, it is possible to preferably suppress the generation of unnecessary radiation noise caused by the current Is1 flowing through the connector unit 70 connecting the first circuit board 61 and the second circuit board 62. In other words, the energy of the current Is1 flowing through the connector unit 70 and the return current Ir1 is balanced, and excess energy is unlikely to be generated, so that the unnecessary radiation noise caused by the excess energy can be preferably suppressed.

[0077] Furthermore, since the metal member 80 has the first connection portion 85a and the second connection portion 85b, the first ground layer 61g of the first circuit board 61 and the second ground layer 62g of the second circuit board 62 can be electrically connected via the metal member 80. This makes it possible to more suitably stabilize the potential of each ground layer. Therefore, it is possible to more suitably suppress the unwanted radiation noise caused by the current Is1 flowing through the signal lines 61d, 62d, etc. along each ground layer.

[0078] Furthermore, the metal member 80 can provide a path of the return current, such as the first ground layer 61g and the second ground layer 62g, for the connector unit 70. Therefore, even if each connector of the connector unit 70 is separated from each circuit board, the metal member 80 can provide a path of the return current Ir1 for each connector separated from each circuit board. This can shorten the path of the return current Ir1 for each connector and each wiring layer provided on each circuit board, compared to a case in which the metal member 80 is not provided. Therefore, it is possible to easily design the path of the return current Ir1 for each connector, and to prevent the quality of the signal flowing through each connector from deteriorating.

[0079] Furthermore, by covering at least a portion of the connector unit 70 with the cover portion 80a of the metal member 80, it is possible to block at least a portion of the electromagnetic waves generated from the connector unit 70 by the cover portion 80a. This makes it possible to prevent the electromagnetic waves generated from the connector unit 70 from leaking outside the circuit board unit 60.

[0080] According to the present embodiment, the cover 80a has a protruding wall 83 that protrudes from the opposing wall 81 toward one of the first circuit board 61 and the second circuit board 62. The protruding wall 83 faces the connector unit 70 in a second horizontal direction Y that is perpendicular to the up-down direction Z that is perpendicular to the plate surface of the first circuit board 61. Therefore, the protruding wall 83 can be brought closer to the first ground layer 61g of the first circuit board 61 or the second ground layer 62g of the second circuit board 62. This makes it easier to propagate the return current Ir1 between the first ground layer 61g or the second ground layer 62g and the metal member 80. Therefore, the return current Ir1 can be more suitably caused to flow through the metal member 80, and the generation of unnecessary radiation noise caused by the current Is1 flowing through the connector unit 70 can be more suitably suppressed. Furthermore, since the connector unit 70 can be covered in the second horizontal direction Y by the protruding wall portion 83, a portion of the electromagnetic waves generated from the connector unit 70 can be blocked by the protruding wall portion 83. This makes it possible to further prevent the electromagnetic waves generated from the connector unit 70 from leaking outside the circuit board unit 60.

[0081] According to the present embodiment, the cover 80a has a protruding wall 83 that protrudes from the opposing wall 81 toward the other of the first circuit board 61 and the second circuit board 62. In the present embodiment, the protruding wall 83 that protrudes toward the first circuit board 61 is a protruding wall 83a serving as a first protruding wall, and the protruding wall 83 that protrudes toward the second circuit board 62 is a protruding wall 83b serving as a second protruding wall. The protruding wall 83a and the protruding wall 83b are provided to sandwich the connector unit 70 in the second horizontal direction Y. The protruding wall 83a serving as the first protruding wall protrudes from the opposing wall 81 toward the first circuit board 61. The protruding wall 83b serving as the second protruding wall protrudes from the opposing wall 81 toward the second circuit board 62. Therefore, the protruding wall 83a can be disposed close to the first ground layer 61g, and the protruding wall 83b can be disposed close to the second ground layer 62g. This makes it easier for the return current Ir1 to propagate both between the first ground layer 61g and the metal member 80 and between the second ground layer 62g and the metal member 80. Therefore, the return current Ir1 can be more suitably caused to flow through the metal member 80, and the generation of unwanted radiation noise caused by the current Is1 flowing through the connector unit 70 can be more suitably suppressed.

[0082] Furthermore, according to this embodiment, a gap is provided between the protruding wall portion 83 and each circuit board. Therefore, the signal lines 61d, 62d connected to the connector unit 70 can be formed on the portion of the upper surface of each circuit board that faces the protruding wall portion 83. This makes it possible to prevent the wiring pattern formed on each circuit board from becoming complicated.

[0083] Further, according to the present embodiment, the cover portion 80a has a connection wall portion 84 that connects at least one of the first connection portion 85a and the second connection portion 85b to the opposing wall portion 81. The connection wall portion 84 faces the connector unit 70 in the first horizontal direction X that is perpendicular to both the up-down direction Z and the second horizontal direction Y. Therefore, the connection wall portion 84 connects at least one of the first connection portion 85a and the second connection portion 85b to the opposing wall portion 81, and supports the opposing wall portion 81. This allows the opposing wall portion 81 to be suitably disposed at a position that faces the connector unit 70 in the up-down direction Z. In addition, the connection wall portion 84 can cover the connector unit 70 in the first horizontal direction X, so that a part of the electromagnetic waves generated from the connector unit 70 can be blocked by the connection wall portion 84. This makes it possible to further suppress the electromagnetic waves generated from the connector unit 70 from leaking to the outside of the circuit board unit 60.

[0084] According to the present embodiment, the cover 80a has a connection wall 84a as a first connection wall, and a connection wall 84b as a second connection wall arranged on the opposite side of the connection wall 84a as the first connection wall and connected to the opposing wall 81. The connection wall 84a and the connection wall 84b are provided to sandwich the connector unit 70 in the first horizontal direction X. Therefore, the opposing wall 81 can be supported by the connection wall 84a and the connection wall 84b. This allows the opposing wall 81 to be more stably disposed with respect to the connector unit 70. In addition, since the opposing wall 81 can be prevented from being cantilevered in the first horizontal direction X, the end of the opposing wall 81 in the first horizontal direction X can be prevented from vibrating electrically. This prevents the opposing wall 81 from becoming an antenna that emits unnecessary radiation noise.

[0085] According to the present embodiment, a pair of fixing parts 82a, 82b are provided, each connected to a pair of connecting walls 84a, 84b, and each fixing part 82a, 82b is provided with a first connecting part 85a and a second connecting part 85b. Therefore, the pair of first connecting parts 85a and the pair of second connecting parts 85b can more suitably electrically connect the first ground layer 61g and the second ground layer 62g. This can more suitably stabilize the potential of each ground layer. Therefore, the unnecessary radiation noise caused by the current Is1 flowing through the signal lines 61d, 62d along each ground layer can be more suitably suppressed.

[0086] According to this embodiment, the metal member 80 is a sheet metal member. The protruding wall portion 83 is a portion bent in the up-down direction Z from an edge of the opposing wall portion 81 in the second horizontal direction Y. The connecting wall portion 84 is a portion bent in the up-down direction Z from an edge of the opposing wall portion 81 in the first horizontal direction X. By forming the protruding wall portion 83 and the connecting wall portion 84 by bending them relative to the opposing wall portion 81 in this manner, it is possible to easily adjust the dimensions of the protruding wall portion 83 in the up-down direction Z and the dimensions of the connecting wall portion 84 in the up-down direction Z individually. Therefore, it is possible to easily form the cover portion 80a in accordance with the dimensions of the connector unit 70 in the up-down direction Z, etc.

[0087] According to the present embodiment, the cover portion 80a has bent portions 83c and 83d bent from an edge portion of the protruding wall portion 83 in the first horizontal direction X in the second horizontal direction Y. At least a part of the bent portions 83c and 83d is disposed between the connection wall portion 84 and the connector unit 70 in the first horizontal direction X. Therefore, at least a part of the gap between the protruding wall portion 83 and the connection wall portion 84, which occurs when the protruding wall portion 83 and the connection wall portion 84 are respectively bent, can be blocked by the bent portions 83c and 83d. This allows the connector unit 70 to be more suitably covered by the cover portion 80a, and the leakage of electromagnetic waves generated from the connector unit 70 to the outside can be more effectively suppressed.

[0088] Furthermore, according to this embodiment, the plate surface of the first circuit board 61 and the plate surface of the second circuit board 62 are parallel to each other. The first circuit board 61 and the second circuit board 62 are arranged side by side in the second horizontal direction Y along the plate surfaces of the first circuit board 61 and the second circuit board 62. Therefore, the metal member 80 has a relatively simple structure, and the connector unit 70 that connects the first circuit board 61 and the second circuit board 62 can be easily and suitably covered by the cover portion 80a.

[0089] Moreover, according to the present embodiment, the first connection portion 85a and the second connection portion 85b are connected to each other. Therefore, the structure of the metal member 80 can be prevented from becoming complicated, compared to a case in which the first connection portion 85a and the second connection portion 85b are provided separately. Furthermore, the first ground layer 61g and the second ground layer 62g can be electrically connected to each other via the first connection portion 85a and the second connection portion 85b that are connected to each other. Therefore, it is easier to electrically connect the first ground layer 61g and the second ground layer 62g more suitably.

[0090] According to this embodiment, the first connector 71b of the first connector 71 protrudes from the first housing 71a that holds the first connector 71b. The facing wall 81 faces the first connector 71b and the first housing 71a in the vertical direction Z that is perpendicular to the plate surface of the first circuit board 61. The end of the facing wall 81 on the side where the first connector 71b protrudes relative to the first housing 71a is located outside the end of the first connector 71b on the side where the first connector 71b protrudes relative to the first housing 71a. Therefore, the facing wall 81 can easily and suitably cover the first connector 71 from above. In addition, when a protruding wall 83a protruding downward is provided at the end of the facing wall 81 on the side where the first connector 71b protrudes relative to the first housing 71a, the protruding wall 83a can be disposed at a position that does not overlap the first connector 71b in the vertical direction Z. Therefore, the lower end of the protruding wall portion 83a can be suitably brought close to the first circuit board 61 while preventing the lower end of the protruding wall portion 83a from contacting the first connector 71b. This makes it easier for the return current Ir1 to flow between the protruding wall portion 83a and the first ground layer 61g. The same applies to the relationship between the second connector 72b of the second connector 72 and the opposing wall portion 81.

[0091] Hereinafter, embodiments different from the above-described embodiments will be described. In the following description of each embodiment, the description of the same configuration as that described above in the description of each embodiment may be omitted by appropriately assigning the same reference numerals. In addition, the parts corresponding to the respective parts of the configuration described above in the description of each embodiment may be assigned the same names and different reference numerals to describe the differences from the above-described configuration, and the description of the similarities to the above-described configuration may be omitted. Note that, as the configuration whose description is omitted in each of the following embodiments, the same configuration as that described above in the description of each embodiment may be adopted within a range that does not contradict.

[0092] <Second embodiment> In this embodiment, the shape of the metal member 280 is different from that of the first embodiment. FIG. 7 is a cross-sectional view showing the metal member 280 of this embodiment. As shown in FIG. 7, the cover portion 280a of the metal member 280 does not have the bent portions 83c, 83d, unlike the cover portion 80a of the first embodiment. Therefore, it is not necessary to perform a bending process to form the bent portions 83c, 83d. This makes it easier to manufacture the metal member 280. The other configurations of the cover portion 280a are the same as the other configurations of the cover portion 80a in the first embodiment. The other configurations of the metal member 280 are the same as the other configurations of the metal member 80 in the first embodiment.

[0093] <Third embodiment> In this embodiment, the shape of the metal member 380 is different from that of the first embodiment. FIG. 8 is a perspective view showing a part of the circuit board unit 360 of this embodiment. FIG. 9 is a cross-sectional view showing a part of the circuit board unit 360 of this embodiment. As shown in FIGS. 8 and 9, in the cover portion 380a of the metal member 380, a pair of protruding walls 383a, 383b and a pair of connecting walls 384a, 384b are connected to each other in the direction surrounding the connector unit 70, and form a rectangular frame-shaped wall portion surrounding the connector unit 70 around an axis extending in the vertical direction Z. In this embodiment, the cover portion 380a is made by drawing a metal plate. The upper end portion of the rectangular frame-shaped wall portion formed by the pair of protruding walls 383a, 383b and the pair of connecting walls 384a, 384b is connected to the outer periphery of the opposing wall portion 381 over the entire circumference.

[0094] As shown in FIG. 9, the protruding wall portion (first protruding wall portion) 383a is in contact with the first circuit board 361. More specifically, the lower end of the protruding wall portion 383a is in contact with the upper surface of the first circuit board 361. A protruding edge portion 383f that protrudes toward the other side in the second horizontal direction, i.e., the -Y side, is formed at the lower end of the protruding wall portion 383a. The protruding edge portion 383f is in contact with the upper surface of the first circuit board 361. As shown in FIG. 8, the protruding edge portion 383f extends in the first horizontal direction X to connect the fixing portion 382a and the fixing portion 382b. The fixing portions 382a and 382b are similar to the fixing portions 82a and 82b of the first embodiment except that the engaging claw portions 82g and 82h are not provided.

[0095] As shown in FIG. 9, the protruding wall portion (second protruding wall portion) 383b is in contact with the second circuit board 362. More specifically, the lower end of the protruding wall portion 383b is in contact with the upper surface of the second circuit board 362. A protruding edge portion 383g that protrudes toward one side in the second horizontal direction, i.e., the +Y side, is formed at the lower end of the protruding wall portion 383b. The protruding edge portion 383g is in contact with the upper surface of the first circuit board 361. The protruding edge portion 383g extends in the first horizontal direction X and connects the fixing portion 382a and the fixing portion 382b. The other configurations of the cover portion 380a are similar to the other configurations of the cover portion 380a in the first embodiment. The other configurations of the metal member 380 are similar to the other configurations of the metal member 80 in the first embodiment.

[0096] A pad portion 361e to which the first connector 71b is electrically connected is formed on the upper surface of the first circuit board 361. A signal line 361c is formed on the lower surface of the first circuit board 361. The pad portion 361e and the signal line 361c are electrically connected by a conductive portion 361d. The conductive portion 361d is, for example, a via that penetrates the first circuit board 361 in the up-down direction Z. In this embodiment, the first connector 71b is electrically connected to a signal line 361c provided on the surface of the first circuit board 361 opposite to the surface to which the first connector 71b is connected, through the conductive portion 361d formed on the first circuit board 361. The other configurations of the first circuit board 361 are similar to the other configurations of the first circuit board 61 in the first embodiment.

[0097] A pad portion 362e to which the second connector 72b is electrically connected is formed on the upper surface of the second circuit board 362. A signal line 362c is formed on the lower surface of the second circuit board 362. The pad portion 362e and the signal line 362c are electrically connected by a conductive portion 362d. The conductive portion 362d is, for example, a via that penetrates the second circuit board 362 in the up-down direction Z. In this embodiment, the second connector 72b is electrically connected to a signal line 362c provided on the surface of the second circuit board 362 opposite to the surface to which the second connector 72b is connected, through the conductive portion 362d formed on the second circuit board 362. The other configurations of the second circuit board 362 are similar to the other configurations of the second circuit board 62 in the first embodiment. The other configurations of the circuit board unit 360 are similar to the other configurations of the circuit board unit 60 in the first embodiment.

[0098] According to this embodiment, the protruding wall portion 383a is in contact with the first circuit board 361. Therefore, the protruding wall portion 383a can be disposed suitably close to the first ground layer 61g. This allows the return current Ir1 to flow more easily between the protruding wall portion 383a and the first ground layer 61g. Moreover, according to this embodiment, the protruding wall portion 383b is in contact with the second circuit board 362. Therefore, the protruding wall portion 383b can be disposed suitably close to the second ground layer 62g. This allows the return current Ir1 to flow more easily between the protruding wall portion 383b and the second ground layer 62g.

[0099] According to this embodiment, the first connector 71b is electrically connected to the signal line 361c provided on the surface of the first circuit board 361 opposite to the surface to which the first connector 71b is connected, via the conductive portion 361d formed on the first circuit board 361. Therefore, even if the protruding wall portion 383a is brought into contact with the first circuit board 361, the first connector 71b can be suitably connected to the signal line 361c. According to this embodiment, the second connector 72b is electrically connected to the signal line 362c provided on the surface of the second circuit board 362 opposite to the surface to which the second connector 72b is connected, via the conductive portion 362d formed on the second circuit board 362. Therefore, even if the protruding wall portion 383b is brought into contact with the second circuit board 362, the second connector 72b can be suitably connected to the signal line 362c.

[0100] According to the present embodiment, the upper end of the rectangular frame-shaped wall portion formed by the pair of protruding walls 383a, 383b and the pair of connecting walls 384a, 384b is connected to the outer periphery of the opposing wall portion 381 over the entire circumference. Therefore, the rectangular frame-shaped wall portion can surround the connector unit 70 over the entire circumference around the axis extending in the vertical direction Z, and the occurrence of gaps between the opposing wall portion 381, the protruding walls 383a, 383b, and the connecting wall portion (first connecting wall portion) 384a and the connecting wall portion (second connecting wall portion) 384b is suppressed. This makes it easier for the cover portion 380a to more suitably block electromagnetic waves generated from the connector unit 70. Therefore, it is possible to more suitably suppress leakage of electromagnetic waves generated from the connector unit 70 to the outside. Furthermore, in the case of such a configuration, the cover portion 380a having the opposing wall portion 381, the pair of protruding walls 383a, 383b, and the pair of connecting walls 384a, 384b can be easily formed by drawing the metal sheet. Therefore, the metal member 380 can be easily manufactured.

[0101] In this embodiment, the signal line 361c may be provided on the inner layer of the first circuit board 361, as shown by the two-dot chain line in Fig. 9. Even in this case, the first connector 71b can be suitably connected to the signal line 361c while the protruding wall portion 383a is in contact with the first circuit board 361. Moreover, the signal line 362c may be provided on the inner layer of the second circuit board 362, as shown by the two-dot chain line in Fig. 9. Even in this case, the second connector 72b can be suitably connected to the signal line 362c while the protruding wall portion 383b is in contact with the second circuit board 362.

[0102] <Fourth embodiment> This embodiment is different from the third embodiment in that the protruding wall portions 383a and 383b of the metal member 380 are electrically connected to the respective ground layers. FIG. 10 is a cross-sectional view showing a part of the circuit board unit 460 of this embodiment. As shown in FIG. 10, a ground pad portion 461e is formed on the upper surface of the first circuit board 461. In this embodiment, the ground pad portion 461e is provided in the same layer as the pad portion 361e, and is electrically connected to the first ground layer 61g through a via 461f formed in the first insulating layer 61a. Note that the ground pad portion 461e may be a portion of the first ground layer 61g exposed on the upper surface of the first circuit board 461 through an opening portion formed in the first insulating layer 61a. The lower end portion of the protruding wall portion 383a is in contact with the ground pad portion 461e. As a result, the protruding wall portion 383a is electrically connected to the first ground layer 61g through the ground pad portion 461e.

[0103] A ground pad portion 462e is formed on the upper surface of the second circuit board 462. In this embodiment, the ground pad portion 462e is provided in the same layer as the pad portion 362e, and is electrically connected to the second ground layer 62g through a via 462f formed in the second insulating layer 62a. The ground pad portion 462e may be a portion of the second ground layer 62g exposed on the upper surface of the second circuit board 462 through an opening formed in the second insulating layer 62a. The lower end of the protruding wall portion 383b is in contact with the ground pad portion 462e. As a result, the protruding wall portion 383b is electrically connected to the second ground layer 62g through the ground pad portion 462e.

[0104] Other configurations of first circuit board 461 are similar to other configurations of first circuit board 361 in the third embodiment. Other configurations of second circuit board 462 are similar to other configurations of second circuit board 362 in the third embodiment. Other configurations of circuit board unit 460 are similar to other configurations of circuit board unit 360 in the third embodiment.

[0105] According to this embodiment, the protruding wall portion 383a is electrically connected to the first ground layer 61g via the ground pad portion 461e formed on the plate surface of the first circuit board 461. Therefore, the first ground layer 61g and the metal member 380 can be electrically connected. This makes it possible for the return current Ir1 to more suitably flow between the protruding wall portion 383a and the first ground layer 61g. Also, according to this embodiment, the protruding wall portion 383b is electrically connected to the second ground layer 62g via the ground pad portion 462e formed on the plate surface of the second circuit board 462. Therefore, the second ground layer 62g and the metal member 380 can be electrically connected. This makes it possible for the return current Ir1 to more suitably flow between the protruding wall portion 383b and the second ground layer 62g.

[0106] <Fifth embodiment> This embodiment differs from the first embodiment in that the protruding walls 83a, 83b and the bent portions 83c, 83d are not provided on the metal member 580. Fig. 11 is a perspective view showing a portion of a circuit board unit 560 of this embodiment. Fig. 12 is a plan view showing a portion of a circuit board unit 560 of this embodiment. Fig. 13 is a cross-sectional view showing a portion of a circuit board unit 560 of this embodiment, taken along the line XIII-XIII in Fig. 12.

[0107] As shown in Figs. 11 to 13, in the circuit board unit 560 of this embodiment, the cover portion 580a of the metal member 580 does not have the protruding wall portions 83a, 83b and the bent portions 83c, 83d, unlike the first embodiment. The other configurations of the cover portion 580a are similar to the other configurations of the cover portion 80a in the first embodiment. The metal member 580 has the fixing portions 382a, 382b similar to the third embodiment. The other configurations of the metal member 580 are similar to the other configurations of the metal member 80 in the first embodiment. The other configurations of the circuit board unit 560 are similar to the other configurations of the circuit board unit 60 in the first embodiment.

[0108] 12, in this embodiment, when a current Is1 flows through connector unit 70, return currents Ir2 and Ir3 flowing through different paths are generated. Note that Figs. 11 to 13 show an example in which current Is1 flows from first circuit board 61 to second circuit board 62.

[0109] As shown in FIG. 13, the return current Ir2 is a return current flowing through the opposing wall 81. In this embodiment, since the protruding walls 83a and 83b are not provided, the return current Ir2 flowing through the second ground layer 62g is directly propagated to the edge of the opposing wall 81 on one side in the second horizontal direction. In this case, the return current Ir2 flows in a state of electric field distribution in the opposing wall 81. The return current Ir2 flowing through the opposing wall 81 in a state of electric field distribution flows from the edge of the opposing wall 81 on the other side in the second horizontal direction to the first ground layer 61g. In FIG. 11, the return current Ir2 generated by the current Is1 flowing through the pair of the first connector 71b and the second connector 72b is indicated by a dashed arrow. The return current Ir2 flowing in a state of electric field distribution is larger the closer it is to the first connector 71b and the second connector 72b, and is smaller the farther it is from the first connector 71b and the second connector 72b.

[0110] 12, the return current Ir3 is a return current flowing through the fixed parts 382a and 382b. The return current Ir3 includes the return current Ir3 flowing from the second ground layer 62g of the second circuit board 62 through the fixed part 382a to the first ground layer 61g of the first circuit board 61, and the return current Ir3 flowing from the second ground layer 62g of the second circuit board 62 through the fixed part 382b to the first ground layer 61g of the first circuit board 61. The amount of the return current Ir3 is greater than the amount of the return current Ir2. The return current Ir2 and the return current Ir3 branch off from the second ground layer 62g, flow through different parts of the metal member 580, and join at the first ground layer 61g.

[0111] As described above, in the present embodiment as well, the return currents Ir2 and Ir3 corresponding to the current Is1 flowing through the connector unit 70 can be suitably flowed via the metal member 580. Therefore, the generation of unnecessary radiation noise caused by the current flowing through the connector unit 70 can be suitably suppressed.

[0112] Furthermore, according to this embodiment, there is no need to provide the protruding walls 83a and 83b on the metal member 580, which further simplifies the structure of the metal member 580. This makes it easier to manufacture the metal member 580.

[0113] Sixth embodiment This embodiment is different from the first embodiment in the relative arrangement of a first circuit board 661 and a second circuit board 662. Fig. 14 is a perspective view showing a part of a circuit board unit 660 of this embodiment. Fig. 15 is a cross-sectional view showing a part of a circuit board unit 660 of this embodiment.

[0114] As shown in Figs. 14 and 15, in this embodiment, the plate surface of the first circuit board 661 and the plate surface of the second circuit board 662 face in directions intersecting each other. More specifically, the plate surface of the first circuit board 661 faces the second horizontal direction Y. The plate surface of the second circuit board 662 faces the up-down direction Z. The first circuit board 661 is disposed apart from the other side in the second horizontal direction of the second circuit board 662, i.e., above the end on the -Y side. In this embodiment, the first circuit board 661 and the second circuit board 662 are disposed along an L shape when viewed in the first horizontal direction X.

[0115] In this embodiment, the "first direction" perpendicular to the plate surface of the first circuit board 661 is the second horizontal direction Y. The "second direction" perpendicular to the first direction is the up-down direction Z. The "third direction" perpendicular to both the first and second directions is the first horizontal direction X.

[0116] The first connector 671 and the second connector 672 of the connector unit 670 are connected in the up-down direction Z. The first connector 671 is located above the second connector 672. The first connector 671 is similar to the first connector 71 in the first embodiment, except that the orientation of the attached first circuit board 661 is different. As shown in FIG. 15, the first connector 671 has a first housing 671a which is a holding portion, and a first connector 671b held by the first housing 671a. The first connector 671b has a first extension portion 671c, a second extension portion 671d, and a board connection portion 671e. The first extension portion 671c extends in the up-down direction Z. The lower end of the first extension portion 671c is exposed in a recess (not shown) formed in the first housing 671a and opening downward. An upper end of the first extending portion 671c protrudes upward from the first housing 671a and is exposed from the first housing 671a, so that the first connecting terminal 671b of the first connector 671 protrudes upward from the first housing 671a.

[0117] The second extending portion 671d extends from an upper end of the first extending portion 671c toward the other side in the second horizontal direction, i.e., toward the -Y side and diagonally upward. The board connecting portion 671e extends upward from an end of the second extending portion 671d on the other side in the second horizontal direction. The board connecting portion 671e is electrically connected to a signal line 661d formed on one side in the second horizontal direction of the first circuit board 661, i.e., on the surface on the +Y side.

[0118] The second connector 672 has a second housing 672a which is a holding portion, and a second connector 672b held by the second housing 672a. The second connector 672b has a first extension portion 672c, a second extension portion 672d, a third extension portion 672f, and a board connection portion 672e. The first extension portion 672c extends in the second horizontal direction Y. An end portion of the first extension portion 672c on one side in the second horizontal direction, i.e., on the +Y side, protrudes from the second housing 672a to one side in the second horizontal direction and is exposed from the second housing 672a. As a result, the second connector 672b of the second connector 672 protrudes from the second housing 672a in the second horizontal direction Y. The second extending portion 672d extends downward and diagonally toward one side in the second horizontal direction from one end of the first extending portion 672c in the second horizontal direction. The board connecting portion 672e extends toward one side in the second horizontal direction from the lower end of the second extending portion 672d. The board connecting portion 672e is electrically connected to a signal line 662d formed on the upper surface of the second circuit board 662.

[0119] The third extension portion 672f extends upward from the end of the first extension portion 672c on the other side in the second horizontal direction, i.e., the -Y side. The upper end of the third extension portion 672f is inserted into a recess (not shown) formed in the first housing 671a and contacts the first extension portion 671c of the first connector 671b exposed in the recess. This electrically connects the first connector 671b and the second connector 672b to each other.

[0120] 14, metal member 680 is a sheet metal member. Metal member 680 has a cover portion 680a and fixing portions 682a, 682b, 682c, and 682d. Cover portion 680a has an opposing wall portion 681 and a bent portion 684. Opposing wall portion 681 has a first portion 681a and a second portion 681b. First portion 681a and second portion 681b are connected to each other and bent toward each other.

[0121] The first portion 681a faces the connector unit 670 in the second horizontal direction Y perpendicular to the plate surface of the first circuit board 661. In this embodiment, the first portion 681a has a plate surface facing the second horizontal direction Y and is a substantially rectangular plate that is long in the first horizontal direction X. The first portion 681a is located on one side in the second horizontal direction, i.e., the +Y side, of the first connector 671 and the second connector 672, and faces the first connector 671 and the second connector 672 in the second horizontal direction Y with a gap therebetween.

[0122] As shown in FIG. 15, the first portion 681a faces a first side surface 671g of the first connector 671. The first side surface 671g is a surface on one side in the second horizontal direction of the first housing 671a, that is, the +Y side. The first portion 681a also faces a side surface 672g on one side in the second horizontal direction of the second housing 672a. In this embodiment, the first portion 681a covers the entire connector unit 670, except for the lower end portion of the second connector 672, from one side in the second horizontal direction. The first portion 681a is located above the second circuit board 662 and away from the second circuit board 662. The lower end portion of the first portion 681a is located below the first extension portion 672c and above the board connection portion 672e. The first portion 681a overlaps with the first circuit board 661 when viewed in the second horizontal direction Y perpendicular to the plate surface of the first circuit board 661, and also overlaps with the second circuit board 662 when viewed in the vertical direction Z perpendicular to the plate surface of the second circuit board 662.

[0123] The first portion 681a is located on one side in the second horizontal direction, i.e., on the +Y side, of the board connecting portion 672e. In this embodiment, the first portion 681a is an end portion on one side in the second horizontal direction of the opposing wall portion 681. In other words, the end portion of the opposing wall portion 681 on the side where the second connector 672b protrudes relative to the second housing 672a serving as the holding portion, i.e., on the +Y side, is located outside the end portion of the second connector 672b on the side where the second connector 672b protrudes relative to the second housing 672a.

[0124] The distance in the second horizontal direction Y between the first portion 681a and the first housing 671a of the first connector 671 is, for example, smaller than the dimension in the up-down direction Z of the connector unit 670. The distance in the second horizontal direction Y between the first portion 681a and the first housing 671a is, for example, smaller than the dimension in the up-down direction Z of the first connector 671 and the dimension in the up-down direction Z of the second connector 672. The distance in the second horizontal direction Y between the first portion 681a and the first housing 671a is, for example, about 0.5 mm or more and 20 mm or less. The distance in the second horizontal direction Y between the first portion 681a and the first housing 671a is preferably, for example, smaller than 10 mm. The distance in the second horizontal direction Y between the first portion 681a and the first housing 671a is similar to the distance in the second horizontal direction Y between the first portion 681a and the second housing 672a.

[0125] The second portion 681b is a portion that faces the connector unit 670 in the up-down direction Z that is perpendicular to the plate surface of the second circuit board 662. As shown in FIG. 14, in this embodiment, the second portion 681b has a plate surface facing the up-down direction Z and is a substantially rectangular plate that is long in the first horizontal direction X. The second portion 681b protrudes from the upper end of the first portion 681a toward the other side in the second horizontal direction, i.e., the -Y side. In this embodiment, the second portion 681b is a portion that is bent from the upper end of the first portion 681a toward the other side in the second horizontal direction, i.e., the -Y side.

[0126] The second portion 681b is located on the upper side of the first connector 671 and faces the first connector 671 in the up-down direction Z with a gap therebetween. As shown in FIG. 15, the second portion 681b faces a second side 671h, which is different from the first side 671g among the side surfaces of the first connector 671. The second side 671h is the upper surface of the first housing 671a. In this embodiment, the second portion 681b covers the entire connector unit 670 from above, except for the end of the first connector 671 on the other side in the second horizontal direction, i.e., on the -Y side. The second portion 681b is located away from the first circuit board 661 on one side in the second horizontal direction, i.e., on the +Y side. The end of the second portion 681b on the other side in the second horizontal direction is located on the other side in the second horizontal direction of the first extension portion 671c and on the one side in the second horizontal direction of the board connection portion 671e. The second portion 681b overlaps with the first circuit board 661 when viewed in the second horizontal direction Y perpendicular to the plate surface of the first circuit board 661, and also overlaps with the second circuit board 662 when viewed in the vertical direction Z perpendicular to the plate surface of the second circuit board 662.

[0127] The second portion 681b is located above the board connecting portion 671e. In this embodiment, the second portion 681b is an upper end portion of the opposing wall portion 681. In other words, the side where the first connector 671b protrudes relative to the first housing 671a serving as the holder, i.e., the end portion of the opposing wall portion 681 on the upper side, is located outside the end portion of the first connector 671b on the side where the first connector 671b protrudes relative to the first housing 671a.

[0128] The distance in the up-down direction Z between the second portion 681b and the first housing 671a is, for example, smaller than the dimension of the connector unit 70 in the second horizontal direction Y. The distance in the up-down direction Z between the second portion 681b and the first housing 671a is, for example, smaller than the distance in the second horizontal direction Y between the first portion 681a and the first housing 671a. The distance in the up-down direction Z between the second portion 681b and the first housing 671a is, for example, about 0.5 mm or more and 20 mm or less. It is preferable that the distance in the up-down direction Z between the second portion 681b and the first housing 671a is, for example, smaller than 10 mm.

[0129] As shown in FIG. 14, the bent portion 684 is a portion that is bent from the first portion 681a and connects the first portion 681a and the first connecting portion 685a. In this embodiment, the bent portion 684 is bent from the first portion 681a to the other side in the second horizontal direction, i.e., the -Y side. In this embodiment, the bent portion 684 is a substantially rectangular plate whose plate surface faces the first horizontal direction X and is long in the second horizontal direction Y. The bent portion 684 is provided as a pair of bent portions 684a and 684b. The bent portion 684a extends from an edge of the first portion 681a on one side in the first horizontal direction, i.e., the +X side, to the other side in the second horizontal direction. The bent portion 684b extends from an edge of the first portion 681a on the other side in the first horizontal direction, i.e., the -X side, to the other side in the second horizontal direction. The pair of bent portions 684a, 684b are disposed to sandwich the connector unit 670 in the first horizontal direction X. The bent portion 684a connects the first portion 681a to the first connection portion 685a of the fixed portion 682a. The bent portion 684b connects the first portion 681a to the first connection portion 685a of the fixed portion 682b.

[0130] The fixed portions 682a and 682b are portions fixed to the first circuit board 661. The fixed portion 682a has a first connection portion 685a and a cylindrical portion 682j. The first connection portion 685a has a plate surface facing the second horizontal direction Y and is a substantially rectangular plate shape that is long in the up-down direction Z. The first connection portion 685a of the fixed portion 682a protrudes from the end of the other side of the second horizontal direction, i.e., the -Y side, of the bent portion 684a to one side in the first horizontal direction, i.e., the +X side. The first connection portion 685a of the fixed portion 682a is electrically connected to the first ground layer 61g via the first ground pad portion 661i. The cylindrical portion 682j is cylindrical and protrudes from the first connection portion 685a to one side in the second horizontal direction, i.e., the +Y side. The fixing portion 682a has a female threaded hole 682h that penetrates the first connecting portion 685a and the cylindrical portion 682j in the second horizontal direction Y. A bolt 691 that fixes the fixing portion 682a to the first circuit board 661 is fastened into the female threaded hole 682h from the other side in the second horizontal direction, i.e., the -Y side.

[0131] The fixed portion 682b is disposed symmetrically with respect to the fixed portion 682a in the first horizontal direction X. The first connection portion 685a of the fixed portion 682b protrudes from the end portion of the bent portion 684b on the other side in the second horizontal direction toward the other side in the first horizontal direction, i.e., the -X side. The first connection portion 685a of the fixed portion 682b is electrically connected to the first ground layer 61g via the first ground pad portion 661j. The other configurations of the fixed portion 682b are similar to the other configurations of the fixed portion 682a.

[0132] The fixed portions 682c and 682d are portions fixed to the second circuit board 662. The fixed portion 682c has a second connection portion 685b, a cylindrical portion 682r, and a connection arm portion 682k. The connection arm portion 682k is connected to a lower end portion of the edge portion on one side in the first horizontal direction, i.e., the +X side, of the first portion 681a. The connection arm portion 682k protrudes downward from the first portion 681a. In this embodiment, the connection arm portion 682k is a substantially rectangular plate whose plate surface faces the second horizontal direction Y.

[0133] The second connection portion 685b of the fixed portion 682c protrudes from the lower end of the connection arm portion 682k toward one side in the second horizontal direction, that is, toward the +Y side. The second connection portion 685b is a substantially square plate whose plate surface faces the vertical direction Z. The second connection portion 685b of the fixed portion 682c is electrically connected to the second ground layer 62g via the second ground pad portion 662i. In this embodiment, the first connection portion 685a and the second connection portion 685b are not directly connected to each other. That is, the first connection portion 685a and the second connection portion 685b are separated from each other. The tubular portion 682r is cylindrical and protrudes upward from the second connection portion 685b. The fixed portion 682c has a female screw hole 682p that penetrates the second connection portion 685b and the tubular portion 682r in the vertical direction Z. A bolt 692 for fixing the fixing portion 682c to the second circuit board 662 is screwed into the female screw hole 682p from below.

[0134] The fixed portion 682d is disposed symmetrically with respect to the fixed portion 682c in the first horizontal direction X. The fixed portion 682d is connected to a lower end of the edge of the first portion 681a on the other side in the first horizontal direction, i.e., the -X side. The second connection portion 685b of the fixed portion 682d is electrically connected to the second ground layer 62g via the second ground pad portion 662j. The other configurations of the fixed portion 682d are similar to the other configurations of the fixed portion 682c.

[0135] A current Is2 flows between the first circuit board 661 and the second circuit board 662 via the connector unit 670, transmitting a signal. In the example of Fig. 15, the current Is2 flowing from the first circuit board 661 to the second circuit board 662 is indicated by a dashed arrow. The current Is2 flows from a signal line 661d formed on the first circuit board 661 through the first connector 671b and the second connector 672b in this order, and then flows to a signal line 662d formed on the second circuit board 662. When the current Is2 flows in this manner, a return current Ir4 corresponding to the current Is2 flows.

[0136] In the example of FIG. 15, the return current Ir4 indicated by the dashed arrow is a return current flowing from the second ground layer 62g of the second circuit board 662 to the first ground layer 61g of the first circuit board 661. The return current Ir4 flows in the opposite direction to the current Is2 through a portion of the second ground layer 62g located below the signal line 662d, and then flows from the second ground layer 62g to the first portion 681a of the opposing wall portion 681. Here, the second ground layer 62g and the first portion 681a are not connected by a conductor, but the return current Ir4 generated in response to the high-frequency current Is2 can propagate from the second ground layer 62g to the first portion 681a due to capacitive coupling in space. The return current Ir4 flowing in the first portion 681a flows from the first portion 681a to the second portion 681b, and flows from the second portion 681b to the first ground layer 61g of the first circuit board 661. Although the second portion 681b and the first ground layer 61g are not connected by a conductor, the return current Ir4 generated in response to the high-frequency current Is2 can propagate from the second portion 681b to the first ground layer 61g due to capacitive coupling in space. The return current Ir4 that flows in the first ground layer 61g flows in a portion of the first ground layer 61g located on the other side of the signal line 661d in the second horizontal direction in the opposite direction to the current Is2. In this manner, in this embodiment, the return path through which the return current Ir4 generated when the current Is2 flows in the connector unit 670 is formed by the metal member 680. Note that when the current Is2 flows from the second circuit board 662 to the first circuit board 661, the return current Ir4 flows in the opposite direction to the direction of the dashed arrow shown in FIG. 15, from the first ground layer 61g to the second ground layer 62g.

[0137] According to this embodiment, the plate surface of the first circuit board 661 and the plate surface of the second circuit board 662 face in directions intersecting each other. The opposing wall portion 681 has a first portion 681a that faces the connector unit 670 in the second horizontal direction Y that is perpendicular to the plate surface of the first circuit board 661, and a second portion 681b that faces the connector unit 670 in the up-down direction Z that is perpendicular to the plate surface of the second circuit board 662. Therefore, the opposing wall portion 681 can be suitably arranged with respect to the connector unit 670 that connects the first circuit board 661 and the second circuit board 662 whose plate surfaces are arranged to intersect each other, and a return path through which the return current Ir4 passes through the opposing wall portion 681 can be formed. This makes it possible to suitably suppress the generation of unnecessary radiation noise caused by the current flowing through the connector unit 670. Furthermore, since first portion 681a and second portion 681b can cover connector unit 670 from two different directions, electromagnetic waves generated from connector unit 670 can be suitably blocked by opposing wall portion 681. This can prevent electromagnetic waves generated from connector unit 670 from leaking to the outside of circuit board unit 660.

[0138] According to this embodiment, the first portion 681a and the second portion 681b are connected to each other and bent toward each other. Therefore, the first portion 681a and the second portion 681b can be easily formed by bending the opposing wall portion 681. This simplifies the structure of the opposing wall portion 681 and effectively suppresses the generation of unnecessary radiation noise caused by the current flowing through the connector unit 670.

[0139] Moreover, according to this embodiment, the first connection portion 685a and the second connection portion 685b are separated from each other. Therefore, compared to the case where the first connection portion 685a and the second connection portion 685b are connected to each other, the degree of freedom in arranging the portions to which the respective connection portions are connected on each circuit board can be improved. Therefore, it is easy to suitably arrange the portions to which the respective connection portions are connected on each circuit board according to the electronic elements and wiring patterns mounted on each circuit board.

[0140] In this embodiment, the first portion 681a can be regarded as the “opposing wall portion”, the second portion 681b can be regarded as the “protruding wall portion”, and the bent portion 684 can be regarded as the “connecting wall portion”. In this case, the bent portion 684 which is the connecting wall portion connects only the first connecting portion 685a of the first connecting portion 685a and the second connecting portion 685b to the first portion 681a which is the opposing wall portion.

[0141] The embodiments of the present disclosure are not limited to the above-mentioned embodiments, and the following configurations and methods may be adopted. The metal member may have any configuration as long as it has a first connection portion, a second connection portion, and a cover portion. The number of the first connection portions and the number of the second connection portions are not particularly limited as long as they are one or more. For example, in the above-mentioned first embodiment, only one of the fixing portion 82a and the fixing portion 82b may be provided. Each connection portion may be connected to each circuit board in any manner. Each connection portion may be connected to each circuit board by solder. The cover portion may have any configuration as long as it has an opposing wall portion. The entire opposing wall portion may face the connector unit. In the above-mentioned sixth embodiment, the opposing wall portion 681 may be formed of the first portion 681a, and the second portion 681b may not be provided.

[0142] The connector unit may have any configuration as long as it has a first connector and a second connector connected to each other. The first connector and the second connector may be connected to each other in any manner. The first circuit board and the second circuit board may have any configuration as long as they each have a ground layer. The first circuit board and the second circuit board may be disposed relative to each other in any manner. The first circuit board and the second circuit board may be flexible boards.

[0143] In the above first embodiment, an example in which the present disclosure is applied to a transmissive projector has been described, but the present disclosure can also be applied to a reflective projector. Here, "transmissive" means that the liquid crystal light valve including a liquid crystal panel or the like transmits light. "Reflective" means that the liquid crystal light valve reflects light. Note that the light modulation device is not limited to a liquid crystal panel or the like, and may be, for example, a light modulation device using a micromirror.

[0144] In addition, in the above first embodiment, an example of a projector 1 using three light modulation devices 4R, 4G, and 4B was given, but the present disclosure is also applicable to a projector using only one light modulation device, or a projector using four or more light modulation devices. Furthermore, the electronic device on which the circuit board is mounted and the electronic device on which the circuit board unit is mounted are not limited to projectors, and may be other electronic devices. Furthermore, the configurations and methods described in this specification can be combined as appropriate within a range that does not contradict each other.

[0145] [Summary of this disclosure] The following is a summary of this disclosure.

[0146] (Appendix 1) a first circuit board having a first ground layer; a second circuit board having a second ground layer; a connector unit having a first connector attached to the first circuit board and a second connector attached to the second circuit board; a metal member that connects the first circuit board and the second circuit board; Equipped with The metal member is a first connection portion electrically connected to the first ground layer; a second connection portion electrically connected to the second ground layer; a cover portion that covers at least a portion of the connector unit; having the cover portion has an opposing wall portion, at least a portion of which faces the connector unit in a direction perpendicular to a plate surface of the first circuit board, the opposing wall portion overlaps with the first circuit board when viewed in a direction perpendicular to the plate surface of the first circuit board, and overlaps with the second circuit board when viewed in a direction perpendicular to the plate surface of the second circuit board.

[0147] According to this configuration, while arranging the facing wall portion close to the connector unit, it is possible to easily propagate the return current between the first ground layer of the first circuit board and the facing wall portion, and between the second ground layer of the second circuit board and the facing wall portion. As a result, a return path through which the return current flows between the first circuit board and the second circuit board can be preferably provided by the metal member. Therefore, the electromagnetic field generated by the return current flowing in the metal member can preferably cancel the electromagnetic field generated by the current flowing in the connector unit. Therefore, it is possible to preferably suppress the generation of unnecessary radiation noise caused by the current flowing in the connector unit connecting the first circuit board and the second circuit board. In other words, the energy of the current flowing in the connector unit and the return current is balanced, and excess energy is unlikely to be generated, so that the unnecessary radiation noise caused by the excess energy can be preferably suppressed.

[0148] Furthermore, since the metal member has the first connection portion and the second connection portion, the first ground layer of the first circuit board and the second ground layer of the second circuit board can be electrically connected via the metal member. This makes it possible to more suitably stabilize the potential of each ground layer. Therefore, it is possible to more suitably suppress unwanted radiation noise caused by currents flowing through signal lines or the like along each ground layer.

[0149] Furthermore, the metal member can provide a return current path, such as the first ground layer and the second ground layer, for the connector unit. Therefore, even if each connector of the connector unit is separated from each circuit board, the metal member can provide a return current path for each connector separated from each circuit board. This makes it possible to shorten the return current path of each connector and each wiring layer provided on each circuit board, compared to a case in which the metal member is not provided. Therefore, it is possible to easily design the return current path of each connector, and to prevent deterioration in the quality of signals flowing through each connector.

[0150] Furthermore, by covering at least a portion of the connector unit with the cover made of a metal member, at least a portion of the electromagnetic waves generated from the connector unit can be blocked by the cover, thereby making it possible to prevent the electromagnetic waves generated from the connector unit from leaking outside the circuit board unit.

[0151] (Appendix 2) the cover portion has a first protruding wall portion protruding from the opposing wall portion toward one of the first circuit board and the second circuit board, The circuit board unit described in Appendix 1, wherein the first protruding wall portion faces the connector unit in a second direction perpendicular to a first direction perpendicular to a plate surface of the first circuit board.

[0152] According to this configuration, the first protruding wall portion can be brought closer to the first ground layer of the first circuit board or the second ground layer of the second circuit board. This makes it easier to propagate a return current between the first ground layer or the second ground layer and the metal member. Therefore, the return current can be more suitably caused to flow to the metal member, and the generation of unnecessary radiation noise caused by the current flowing through the connector unit can be more suitably suppressed. In addition, since the first protruding wall portion can cover the connector unit in the second direction, a part of the electromagnetic waves generated from the connector unit can be blocked by the first protruding wall portion. This makes it possible to more suitably suppress the electromagnetic waves generated from the connector unit from leaking outside the circuit board unit.

[0153] (Appendix 3) the cover portion has a second protruding wall portion protruding from the opposing wall portion toward the other of the first circuit board and the second circuit board, the first protruding wall portion and the second protruding wall portion are provided to sandwich the connector unit in the second direction, the first protruding wall portion protrudes from the opposing wall portion toward the first circuit board, The circuit board unit according to claim 2, wherein the second protruding wall portion protrudes from the opposing wall portion toward the second circuit board.

[0154] According to this configuration, the first protruding wall portion can be disposed close to the first ground layer, and the second protruding wall portion can be disposed close to the second ground layer. This makes it easier for the return current to propagate both between the first ground layer and the metal member and between the second ground layer and the metal member. Therefore, the return current can be more suitably caused to flow to the metal member, and the generation of unwanted radiation noise caused by the current flowing through the connector unit can be more suitably suppressed.

[0155] (Appendix 4) 4. The circuit board unit according to claim 2, wherein a gap is provided between the first protruding wall portion and the one of the circuit boards.

[0156] According to this configuration, a signal line connected to the connector unit can be formed on a portion of the surface of the one circuit board that faces the first protruding wall, thereby making it possible to prevent the wiring pattern formed on the one circuit board from becoming complicated.

[0157] (Appendix 5) The circuit board unit according to claim 2 or 3, wherein the first protruding wall portion is in contact with the one of the circuit boards.

[0158] According to this configuration, the first protruding wall portion can be disposed suitably close to the ground layer of one of the circuit boards, which makes it easier for a return current to flow between the first protruding wall portion and the ground layer.

[0159] (Appendix 6) The circuit board unit described in Appendix 5, wherein the first protruding wall portion is electrically connected to one of the first ground layer and the second ground layer, which is provided on the one of the circuit boards, via a ground pad portion formed on a plate surface of the one of the circuit boards.

[0160] According to this configuration, the ground layer provided on one of the circuit boards can be electrically connected to the metal member, which makes it easier for the return current to flow between the first protruding wall portion and the ground layer.

[0161] (Appendix 7) the connector unit has a connector electrically connected to the one circuit board, The circuit board unit described in Appendix 5 or Appendix 6, wherein the connector is electrically connected to a signal line provided on a surface of the one of the circuit boards opposite to the surface to which the connector is connected, or to a signal line provided on an inner layer of the one of the circuit boards, via a conductive portion formed on the one of the circuit boards.

[0162] According to this configuration, even if the first protruding wall portion is brought into contact with one of the circuit boards, the connector can be suitably connected to the signal line.

[0163] (Appendix 8) the cover portion has a first connection wall portion that connects at least one of the first connection portion and the second connection portion to the opposing wall portion, The circuit board unit according to any one of claims 2 to 7, wherein the first connection wall portion faces the connector unit in a third direction perpendicular to both the first direction and the second direction.

[0164] According to this configuration, the first connection wall connects at least one of the first connection portion and the second connection portion to the opposing wall, thereby supporting the opposing wall. This allows the opposing wall to be suitably disposed in a position opposing the connector unit in the first direction. In addition, the first connection wall can cover the connector unit in the third direction, so that the first connection wall can block part of the electromagnetic waves generated from the connector unit. This can further prevent the electromagnetic waves generated from the connector unit from leaking outside the circuit board unit.

[0165] (Appendix 9) the cover portion has a second connecting wall portion that is disposed on the opposite side to the first connecting wall portion and is connected to the opposing wall portion, The circuit board unit described in Appendix 8, wherein the first connection wall portion and the second connection wall portion are arranged on either side of the connector unit in the third direction.

[0166] According to this configuration, the opposing wall portion can be supported by the first connecting wall portion and the second connecting wall portion. This allows the opposing wall portion to be more stably positioned relative to the connector unit. In addition, since the opposing wall portion can be prevented from being cantilevered in the third direction, the end portion of the opposing wall portion in the third direction can be prevented from electrically vibrating. This prevents the opposing wall portion from becoming an antenna that emits unnecessary radiation noise.

[0167] (Appendix 10) the metal member is a sheet metal member, the first protruding wall portion is a portion bent in the first direction from an edge portion in the second direction of the opposing wall portion, 10. The circuit board unit according to claim 8, wherein the first connecting wall portion is a portion bent in the first direction from an edge portion in the third direction of the opposing wall portion.

[0168] According to this configuration, by making the first protruding wall and the first connecting wall by bending them relative to the opposing wall, the dimensions of the first protruding wall and the first connecting wall in the first direction can be easily adjusted individually. Therefore, the cover can be easily made to match the dimensions of the connector unit in the first direction.

[0169] (Appendix 11) the cover portion has a bent portion bent in the second direction from an edge portion in the third direction of the first protruding wall portion, The circuit board unit described in Appendix 10, wherein at least a portion of the bent portion is disposed between the first connection wall portion and the connector unit in the third direction.

[0170] According to this configuration, at least a part of the gap between the first protruding wall portion and the first connecting wall portion that occurs when the first protruding wall portion and the first connecting wall portion are respectively bent can be blocked by the bent portion, which makes it possible to more suitably cover the connector unit with the cover portion and further suppresses leakage of electromagnetic waves generated from the connector unit to the outside.

[0171] (Appendix 12) a surface of the first circuit board and a surface of the second circuit board are parallel to each other; The circuit board unit according to any one of claims 1 to 11, wherein the first circuit board and the second circuit board are arranged side by side in a direction along a plate surface of the first circuit board and a plate surface of the second circuit board.

[0172] According to this configuration, the metal member has a relatively simple structure, and the connector unit that connects the first circuit board and the second circuit board can be easily and suitably covered by the cover portion.

[0173] (Appendix 13) a surface of the first circuit board and a surface of the second circuit board are oriented in directions intersecting each other; The opposing wall portion is a first portion facing the connector unit in a direction perpendicular to a surface of the first circuit board; a second portion facing the connector unit in a direction perpendicular to a surface of the second circuit board; 2. The circuit board unit according to claim 1,

[0174] According to this configuration, the opposing wall can be suitably disposed with respect to the connector unit that connects the first circuit board and the second circuit board whose plate surfaces are arranged to intersect with each other, and a return path can be formed in which the return current passes through the opposing wall. This can suitably suppress the generation of unnecessary radiation noise caused by the current flowing through the connector unit. In addition, since the first and second parts can cover the connector unit from two different directions, the opposing wall can suitably block electromagnetic waves generated from the connector unit. This can suppress the electromagnetic waves generated from the connector unit from leaking outside the circuit board unit.

[0175] (Appendix 14) The circuit board unit described in Appendix 13, wherein the first portion and the second portion are connected to each other and bent toward each other.

[0176] According to this configuration, the first and second portions can be easily formed by bending the opposing wall portion, which simplifies the structure of the opposing wall portion and effectively suppresses the generation of unwanted radiation noise caused by the current flowing through the connector unit.

[0177] (Appendix 15) The circuit board unit according to any one of claims 1 to 14, wherein the first connection portion and the second connection portion are spaced apart from each other.

[0178] This configuration improves the degree of freedom in arranging the portions of each circuit board to which the connection parts are connected, compared to when the first and second connection parts are connected to each other, and therefore makes it easier to suitably arrange the portions of each circuit board to which the connection parts are connected, depending on the electronic elements and wiring patterns mounted on each circuit board.

[0179] (Appendix 16) The circuit board unit according to any one of claims 1 to 14, wherein the first connection portion and the second connection portion are connected to each other.

[0180] This configuration makes it possible to prevent the structure of the metal member from becoming complicated, compared to when the first and second connection parts are provided separately. Also, the first and second ground layers can be electrically connected via the first and second connection parts that are connected to each other. Therefore, it is easier to electrically connect the first and second ground layers more suitably.

[0181] (Appendix 17) a connector of the first connector protrudes from a holding portion of the first connector that holds the connector, the opposing wall portion faces the connector and the holding portion in a direction perpendicular to a plate surface of the first circuit board, A circuit board unit described in any one of Appendix 1 to Appendix 16, wherein an end portion of the opposing wall portion on a side where the connector protrudes relative to the holding portion is positioned outer than an end portion of the connector on a side where the connector protrudes relative to the holding portion.

[0182] According to this configuration, the facing wall portion can easily and suitably cover the first connector in the first direction. Furthermore, when a first protruding wall portion protruding toward the first circuit board is provided at an end of the facing wall portion on the side where the first connector protrudes relative to the holding portion of the first connector, the first protruding wall portion can be disposed at a position where it does not overlap with the first connector in the first direction. Therefore, the first protruding wall portion can be suitably brought close to the first circuit board while preventing the first protruding wall portion from contacting the first connector. This makes it easier for a return current to flow between the first protruding wall portion and the first ground layer.

[0183] (Appendix 18) 18. An electronic device comprising the circuit board unit according to any one of claims 1 to 17.

[0184] According to this configuration, it is possible to suitably suppress the generation of unwanted radiation noise in the electronic device, which is caused by the current flowing through the connector unit. [Explanation of symbols]

[0185] 1...Projector (electronic device), 60,360,460,560,660...Circuit board unit, 61,361,461,661...First circuit board, 61d,62d,361c,362c,661d,662d...Signal line, 61g...First ground layer, 62,362,462,662...Second circuit board, 62g...Second ground layer, 70,670...Connector unit, 71,671...First connector, 71a,671a...First housing (holding portion), 71b,671b...First connector (connector), 72,672...Second connector, 72a,672a...Second housing (holding portion), 72b,672b...Second connector (connector), 80,280,380,580 , 680...metal member, 80a, 280a, 380a, 580a, 680a...cover portion, 81, 381, 681...opposing wall portion, 83a, 383a...protruding wall portion (first protruding wall portion), 83b, 383b...protruding wall portion (second protruding wall portion), 83c, 83d...bent portion, 84a, 384a...connecting wall portion (first connecting wall portion), 84b, 384b...connecting wall portion (second connection wall portion), 85a, 685a...first connection portion, 85b, 685b...second connection portion, 361d, 362d...conductive portion, 461e, 462e...ground pad portion, 681a...first portion, 681b...second portion, X...first horizontal direction (third direction), Y...second horizontal direction (second direction, first direction), Z...vertical direction (first direction, second direction)

Claims

1. a first circuit board having a first ground layer; a second circuit board having a second ground layer; a connector unit having a first connector attached to the first circuit board and a second connector attached to the second circuit board; a metal member connecting the first circuit board and the second circuit board; Equipped with The metal member is a first connection portion electrically connected to the first ground layer; a second connection portion electrically connected to the second ground layer; a cover portion that covers at least a portion of the connector unit; having the cover portion has an opposing wall portion, at least a portion of which faces the connector unit in a direction perpendicular to a plate surface of the first circuit board, The opposing wall portion overlaps with the first circuit board when viewed in a direction perpendicular to the plate surface of the first circuit board, and overlaps with the second circuit board when viewed in a direction perpendicular to the plate surface of the second circuit board.

2. the cover portion has a first protruding wall portion protruding from the opposing wall portion toward one of the first circuit board and the second circuit board, The circuit board unit according to claim 1 , wherein the first protruding wall portion faces the connector unit in a second direction perpendicular to a first direction perpendicular to a plate surface of the first circuit board.

3. the cover portion has a second protruding wall portion protruding from the opposing wall portion toward the other of the first circuit board and the second circuit board, The first protruding wall portion and the second protruding wall portion are provided to sandwich the connector unit in the second direction, the first protruding wall portion protrudes from the opposing wall portion toward the first circuit board, The circuit board unit according to claim 2 , wherein the second protruding wall portion protrudes from the opposing wall portion toward the second circuit board.

4. The circuit board unit according to claim 2 , wherein a gap is provided between the first protruding wall portion and the one of the circuit boards.

5. The circuit board unit according to claim 2 , wherein the first protruding wall portion is in contact with the one of the circuit boards.

6. 6. The circuit board unit according to claim 5, wherein the first protruding wall portion is electrically connected to a ground layer of the first ground layer and the second ground layer provided on the one of the circuit boards via a ground pad portion formed on a plate surface of the one of the circuit boards.

7. the connector unit has a connector electrically connected to the one circuit board, 6. The circuit board unit according to claim 5, wherein the connector is electrically connected, via a conductive portion formed on the one of the circuit boards, to a signal line provided on a surface of the one of the circuit boards opposite to the surface to which the connector is connected, or to a signal line provided on an inner layer of the one of the circuit boards.

8. the cover portion has a first connection wall portion that connects at least one of the first connection portion and the second connection portion to the opposing wall portion, The circuit board unit according to claim 2 , wherein the first connection wall portion faces the connector unit in a third direction that is perpendicular to both the first direction and the second direction.

9. the cover portion has a second connecting wall portion that is disposed on the opposite side to the first connecting wall portion and is connected to the opposing wall portion, The circuit board unit according to claim 8 , wherein the first connection wall portion and the second connection wall portion are provided on either side of the connector unit in the third direction.

10. the metal member is a sheet metal member, the first protruding wall portion is a portion bent in the first direction from an edge portion in the second direction of the opposing wall portion, The circuit board unit according to claim 8 , wherein the first connecting wall portion is a portion bent in the first direction from an edge portion of the opposing wall portion in the third direction.

11. the cover portion has a bent portion bent in the second direction from an edge portion in the third direction of the first protruding wall portion, The circuit board unit according to claim 10 , wherein at least a portion of the bent portion is disposed between the first connection wall portion and the connector unit in the third direction.

12. a surface of the first circuit board and a surface of the second circuit board are parallel to each other; The circuit board unit according to claim 1 , wherein the first circuit board and the second circuit board are arranged side by side in a direction along a plate surface of the first circuit board and a plate surface of the second circuit board.

13. a surface of the first circuit board and a surface of the second circuit board are oriented in directions intersecting each other; The opposing wall portion is a first portion facing the connector unit in a direction perpendicular to a surface of the first circuit board; a second portion facing the connector unit in a direction perpendicular to a surface of the second circuit board; The circuit board unit according to claim 1 .

14. The circuit board unit according to claim 13 , wherein the first portion and the second portion are connected to each other and bent relative to each other.

15. The circuit board unit according to claim 1 , wherein the first connection portion and the second connection portion are spaced apart from each other.

16. The circuit board unit according to claim 1 , wherein the first connection portion and the second connection portion are connected to each other.

17. a connector of the first connector protrudes from a holding portion of the first connector that holds the connector, the opposing wall portion faces the connector and the holding portion in a direction perpendicular to a plate surface of the first circuit board, The circuit board unit according to claim 1 , wherein an end portion of the opposing wall portion on a side where the connector protrudes relative to the holding portion is positioned outer than an end portion of the connector on a side where the connector protrudes relative to the holding portion.

18. An electronic device comprising the circuit board unit according to claim 1 .

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