Electronic device

Abstract

To provide an electronic device capable of suppressing influences of noise between circuit boards.SOLUTION: Circuit boards 30, 40 are electrically connected through an open hole 23 of a cooling plate 21. The circuit boards 30, 40 have electronic components 321, 421 on an opposite surface to the cooling plate 21. An electronic device 10 is provided with an electromagnetic shield body 80. The electromagnetic shield body 80 includes a rand 315 and a veer conductor 316, a ground layer 317, and a shield cover 36. The rand 315 and the veer conductor 316 are electronically connected to the ground layer 317, and encircles the electronic component 321 in a planar view. The ground layer 317 incorporates the ground conductor in a planar view. The shield cover 36 is mounted on the circuit board 30 and is disposed to cover the electronic component 321. The shield cover 36 is electrically connected to the ground layer 317 via the rand 315 and the veer conductor 316.SELECTED DRAWING: Figure 16

Description

[Technical Field]

[0001] TECHNICAL FIELD The disclosure herein relates to electronic devices. [Background technology]

[0002] Patent Document 1 discloses an electronic device in which two circuit boards are arranged with a cooling plate sandwiched between them. The contents of the prior art document are incorporated by reference as explanations of the technical elements in this specification. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 192031 Summary of the Invention [Problem to be solved by the invention]

[0004] One possible structure is to electrically connect two circuit boards through a through-hole in the cooling plate. In this case, noise from an electronic component on one of the circuit boards may affect the electronic component on the other circuit board through the through-hole. In the above-mentioned respects and in other respects not mentioned, further improvements in electronic devices are required.

[0005] One object of the present disclosure is to provide an electronic device that can suppress the influence of noise between circuit boards. [Means for solving the problem]

[0006] An electronic device according to one aspect of the disclosure includes: a cooling plate (21) having one surface (21a), a back surface (21b) opposite to the one surface in a predetermined direction, and through holes (23) opening to the one surface and the back surface; a first circuit board (30) disposed on one surface and having at least one first electronic component (321, 322) on a surface opposite to the one surface; a second circuit board (40) disposed on the rear surface and having at least one second electronic component (421, 422) on a surface facing the rear surface; a connection portion (33, 43) that electrically connects the first circuit board and the second circuit board through the through hole; The shield base (317) is located on one side. a shield cover (36) mounted on the first circuit board and arranged to cover the first electronic component; Equipped with the first circuit board provides a reference potential, is arranged to surround the first electronic component in a plan view in a predetermined direction, and has ground conductors (315, 316) electrically connected to the shield base; the shield base is provided to enclose the ground conductor in a plan view, the shield cover is electrically connected to the shield base via a ground conductor; The first electronic component is disposed inside an electromagnetic shield (80) that includes a shield base, a ground conductor, and a shield cover.

[0007] According to the disclosed electronic device, a shield cover constituting an electromagnetic shield is mounted on a first circuit board. This allows the first electronic component to be disposed inside the shield cover and, ultimately, the electromagnetic shield. The through-hole is provided on the outside of the electromagnetic shield. This prevents noise generated by the first electronic component from acting on the second electronic component through the through-hole. Furthermore, it also prevents noise generated by the second electronic component from acting on the first electronic component through the through-hole. In other words, it is possible to suppress the influence of noise between the circuit boards.

[0008] The various aspects disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims and in this section are intended to exemplify correspondences with the following embodiments and are not intended to limit the technical scope. The objectives, features, and advantages disclosed in this specification will become more apparent by reference to the following detailed description and the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an electronic device according to a first embodiment. [Figure 2] FIG. 2 is a plan view seen from the Z1 direction shown in FIG. [Figure 3] FIG. 3 is a plan view seen from the Y1 direction shown in FIG. [Figure 4] FIG. 3 is a plan view seen from the X1 direction shown in FIG. [Figure 5] FIG. [Figure 6] FIG. 2 is a perspective view showing one surface of a cooling plate. [Figure 7] FIG. 2 is a perspective view showing the back side of the cooling plate. [Figure 8] FIG. [Figure 9] FIG. 2 is a plan view showing a circuit board arranged on one side. [Figure 10] FIG. 2 is a plan view showing a circuit board disposed on the back surface side. [Figure 11] FIG. 10 is a perspective view showing a state in which the cover on one side is omitted. [Figure 12] FIG. 10 is a perspective view showing the positional relationship between a wall portion, an electronic component, lands corresponding to the wall portion, and a back plate on one surface side. [Figure 13] FIG. 2 is a perspective view showing a state in which the cover on the rear side is omitted. [Figure 14] 10 is a perspective view showing the positional relationship between the wall portion, the electronic component, the lands corresponding to the wall portion, and the back plate on the rear surface side. FIG. [Figure 15]FIG. 2 is a cross-sectional view taken along line XV-XV in FIG. [Figure 16] FIG. 1 is a cross-sectional view showing an electromagnetic shield configured in an electronic device. [Figure 17] FIG. 2 is a plan view showing the lands, via conductors, and ground layers that constitute the electromagnetic shield. [Figure 18] FIG. [Figure 19] FIG. [Figure 20] FIG. 10 is a cross-sectional view showing the structure around an electronic component in an electronic device according to a second embodiment. [Figure 21] 10 is a plan view showing the positional relationship between surface wiring and lands that constitute an electromagnetic shield in an electronic device according to a third embodiment. FIG. [Figure 22] FIG. 22 is a cross-sectional view taken along line XXII-XXII shown in FIG. 21. [Figure 23] FIG. 10 is a cross-sectional view showing the structure around an electronic component in an electronic device according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, several embodiments will be described with reference to the drawings. Note that in each embodiment, corresponding components are designated by the same reference numerals, and redundant description may be omitted. When only a portion of the configuration is described in each embodiment, the configuration of another embodiment previously described may be applied to the remaining portion of the configuration. Furthermore, in addition to the combinations of configurations explicitly stated in the description of each embodiment, configurations of several embodiments may be partially combined together even if not explicitly stated, provided that there is no particular problem with the combination.

[0011] (First embodiment) First, a schematic configuration of the electronic device will be described. The electronic device is sometimes called an electronic control unit (ECU). ECU is an abbreviation for Electronic Control Unit. The electronic device may be mounted on, for example, a moving object. The moving object may be, for example, a vehicle, an aircraft, a ship, a construction machine, an agricultural machine, or the like. As an example, the electronic device of this embodiment is mounted on a vehicle.

[0012] <Electronic equipment> FIG. 1 is a perspective view showing an example of an electronic device. FIG. 2 is a plan view of the electronic device as seen from the Z1 direction shown in FIG. 1. FIG. 3 is a plan view of the electronic device as seen from the Y1 direction shown in FIG. 2. FIG. 4 is a plan view of the electronic device as seen from the X1 direction shown in FIG. 2. FIG. 5 is an exploded perspective view of the electronic device. For convenience, gaskets and TIM are omitted from FIG. 5. TIM is an abbreviation for Thermal Interface Material.

[0013] Hereinafter, the thickness direction of the cooling plate (main body) is referred to as the Z direction. Furthermore, one direction perpendicular to the Z direction is referred to as the X direction, and the direction perpendicular to both the Z direction and the X direction is referred to as the Y direction. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. The planar view from the Z direction may be simply referred to as the planar view. The Z direction corresponds to the specified direction.

[0014] As shown in FIGS. 1 to 5, the electronic device 10 includes a cooler 20, circuit boards 30 and 40, a backplate 50, and a housing 60. The cooler 20 includes a cooling plate 21. The circuit board 30 is disposed on one surface of the cooling plate 21 in the Z direction. The circuit board 40 is disposed on the back surface of the cooling plate 21. The backplate 50 is disposed on the surface of the circuit boards 30 and 40 opposite to the surface facing the cooling plate 21. The housing 60 forms at least a part of the outer shell (outer surface) of the electronic device 10.

[0015] As shown in the illustration, the electronic device 10 has a substantially rectangular shape in a plan view in the Z direction. The length of the electronic device 10 in the Z direction is shorter than the lengths in the X direction and the Y direction. The electronic device 10 has a low-profile structure that is thin in the Z direction.

[0016] <Cooler> Fig. 6 and Fig. 7 are perspective views showing a cooling plate of the cooler. Fig. 6 shows one surface side of the cooling plate, and Fig. 7 shows the back surface side. Fig. 8 is a perspective view showing a flow path cover.

[0017] 1 to 8, the cooler 20 includes the above-described cooling plate 21. The cooling plate 21 has a wall portion 22, a through hole 23, a flow path 24, and a fixing portion 25. In addition to the cooling plate 21, the cooler 20 includes an inlet pipe 26, an outlet pipe 27, and a flow path cover 28.

[0018] The cooling plate 21 has one surface 21a and a back surface 21b, which is the surface opposite to the first surface 21a in the Z direction. The cooling plate 21 cools the circuit board 30 arranged on the first surface 21a and the circuit board 40 arranged on the back surface 21b. The cooling plate 21 particularly cools electronic components that generate a large amount of heat and are mounted on the circuit boards 30 and 40. The cooling plate 21 is made of a metal material such as aluminum.

[0019] The cooling plate 21 has a main body 211 and side plate portions 212 and 213. The first surface 21a is one surface of the main body 211, and the back surface 21b is the back surface of the main body 211. The Z direction is the plate thickness direction of the main body 211. The main body 211 has a generally rectangular planar shape with the X direction as its longitudinal direction. In the X direction, the side plate portion 212 is connected to one end of the main body 211, and the side plate portion 213 is connected to the other end of the main body 211. The X direction is the plate thickness direction of the side plate portions 212 and 213. When viewed from the X direction, the side plate portions 212 and 213 have a generally rectangular shape with the Y direction as its longitudinal direction. The side plate portions 212 and 213 are connected to the main body 211 at their intermediate positions in the Z direction. The cooling plate 21 has a generally H shape when viewed from the Y direction. The side plates 212 and 213 together with the housing 60 form the outer shell of the electronic device 10.

[0020] The wall portion 22 has a predetermined height in the Z direction. As shown in FIG. 6, the wall portion 22 includes a wall portion 221 provided on one surface 21a. The wall portion 221 protrudes from the one surface 21a. The wall portion 221 is provided so as to overlap the outer peripheral edge of the circuit board 30 in a plan view, specifically the land 312. The wall portion 221 is provided along the outer periphery of the main body portion 211. The wall portion 221 has a generally rectangular ring shape in plan view with the X direction as its longitudinal direction.

[0021] The wall portion 221 has walls 2211, 2212, and 2213. The wall portion 2211 is provided near both ends of the main body portion 211 in the X direction. One of the walls 2211 is provided near the side plate portion 212, and the other wall portion 2211 is provided near the side plate portion 213. The wall portion 2211 extends approximately in the Y direction. The walls 2212 and 2213 are continuous with the wall portion 2211. The wall portion 2212 is provided near one end of the main body portion 211 in the Y direction, and the wall portion 2213 is provided near the other end of the main body portion 211 in the Y direction. The walls 2212 and 2213 extend approximately in the X direction.

[0022] As shown in FIG. 7, the wall portion 22 includes a wall portion 222 provided on the rear surface 21b. The wall portion 222 protrudes from the rear surface 21b. The wall portion 222 is provided so as to overlap the outer peripheral edge of the circuit board 40, specifically the land 412, in a plan view. Most of the wall portion 222 is provided along the outer periphery of the main body portion 211. The illustrated electronic device 10 includes two circuit boards 40. The circuit boards 40 are arranged side by side in the X direction. Therefore, a portion of the wall portion 224 extends in the Y direction from a middle position in the X direction. The wall portion 224 is not provided in a portion that overlaps with the flow path 24 in a plan view. The wall portion 221 is annular.

[0023] The wall portion 222 has walls 2221, 2222, 2223, and 2224. The wall portion 2221 is provided near both ends of the main body portion 211 in the X direction. One of the walls 2221 is provided near the side plate portion 212, and the other wall portion 2221 is provided near the side plate portion 213. The wall portion 2221 extends approximately in the Y direction. The walls 2222 and 2223 are continuous with the wall portion 2221. The wall portion 2222 is provided near one end of the main body portion 211 in the Y direction, and the wall portion 2223 is provided near the other end of the main body portion 211 in the Y direction. The walls 2222 and 2223 are divided into two parts according to the two circuit boards 40. One of the walls 2222 is continuous with the wall 2221 on the side plate 212 side, and the other wall 2223 is continuous with the wall 2221 on the side plate 213 side. The same is true for the wall 2223. The walls 2222 and 2223 extend substantially in the X direction.

[0024] The wall portion 2224 is disposed opposite the wall portion 2221 in the X direction. The wall portion 2224 corresponds to the lands 412 of the two circuit boards 40 lined up in the X direction, and has a generally U-shaped planar shape so as not to cross the flow path 24. One of the walls 2224 is continuous with the wall portion 2222, and the other of the walls 2224 is continuous with the wall portion 2223. One end of the wall portion 2224 is continuous with the wall portion 2222 on the side plate portion 212 side, and the other end is continuous with the wall portion 2222 on the side plate portion 213 side. The same applies to the wall portion 2224 continuous with the wall portion 2223.

[0025] The through holes 23 are provided to electrically connect the circuit board 30 and the circuit board 40. The through holes 23 penetrate the main body 211 of the cooling plate 21 in the Z direction and open to the one surface 21a and the back surface 21b. The cooling plate 21 has two through holes 23 corresponding to the two circuit boards 40. The through holes 23 are provided near the wall portions 2212, 2222 in the Y direction. The through holes 23 are provided between the wall portions 2212, 2222 and the flow path 24 in the Y direction.

[0026] The flow path 24 is provided so as to overlap at least the heat-generating components in a plan view to effectively cool the circuit boards 30, 40, particularly the heat-generating components. The flow path 24 extends along the arrangement direction of the two circuit boards 40, i.e., the X direction. The flow path 24 is provided so as to overlap the heat-generating components of the circuit board 30 and the heat-generating components of the two circuit boards 40 in a plan view. The flow path 24 is provided near the center of the main body 211 in the Y direction. The flow path 24 is provided recessed toward the one surface 21a. The height of the bottom 24a of the flow path 24 is lower than the height of the wall portion 22 on the one surface 21a.

[0027] The flow paths 24 have a folded structure. The flow paths 24 are separated by partition walls 241 extending in the X direction and are generally U-shaped in plan view. The cooling plate 21 has the partition walls 241, allowing the refrigerant to flow in the X direction up to the vicinity of the side plate portion 213. The side plate portion 212 is provided with a refrigerant inlet portion 242 and an outlet portion 243. The inlet portion 242 and the outlet portion 243 penetrate the side plate portion 212. The refrigerant introduced from the inlet portion 242 flows through the flow paths 24 from the side plate portion 212 side toward the side plate portion 213 side. The folded refrigerant flows through the flow paths 24 from the side plate portion 213 side toward the side plate portion 212 side and is discharged through the outlet portion 243. Note that, for example, a phase-change refrigerant such as water or ammonia, or a phase-non-change refrigerant such as an ethylene glycol-based refrigerant can be used as the refrigerant.

[0028] The inlet pipe 26 is attached to the inlet portion 242 of the cooling plate 21. The outlet pipe 27 is attached to the outlet portion 243. The inlet pipe 26 is a pipe for supplying refrigerant to the cooler 20. The outlet pipe 27 is a pipe for discharging refrigerant from the cooler 20. The attachment positions of the inlet pipe 26 and the outlet pipe 27 are not particularly limited. The inlet pipe 26 and the outlet pipe 27 may be attached to a common surface or to different surfaces. In the illustrated electronic device 10, the inlet pipe 26 and the outlet pipe 27 are attached to the side plate portion 212.

[0029] The flow path cover 28 is a member that covers the flow path 24. Like the cooling plate 21, the flow path cover 28 is formed using a metal material such as aluminum. The peripheral edge of the flow path cover 28 is liquid-tightly joined to the peripheral portion of the flow path 24 in the main body 211 of the cooling plate 21. The flow path cover 28 has a plurality of fins 281 on the surface facing the cooling plate 21. Each of the fins 281 has a predetermined height in the Z direction and extends in the X direction. The plurality of fins 281 are aligned in the Y direction. The presence of the fins 281 increases the contact area with the refrigerant, improving heat exchange with the refrigerant, that is, cooling efficiency.

[0030] The fixing portions 25 of the cooling plate 21 are portions for fixing other elements of the electronic device 10 to the cooling plate 21. The fixing portions 25 are, for example, bosses with screw holes formed therein. The fixing portions 25 include fixing portions 251, 252, and 253 provided on the one surface 21a. The fixing portion 251 is a portion for screwing together the back plate 50 (501) corresponding to the circuit board 30 and the circuit board 30. Two of the fixing portions 251 are provided side by side in the X direction between the wall portion 2212 and the flow path 24. The other two fixing portions 251 are provided side by side in the X direction between the wall portion 2213 and the flow path 24. The four fixing portions 251 are provided near the center of the cooling plate 21 in the X direction.

[0031] The fixing portions 252 are portions for screwing together the cover 61 and the circuit board 30. The four fixing portions 252 are provided near the four corners of the main body 211. The fixing portions 252 are provided outside the wall 221. The fixing portion 253 is a portion for screwing together the circuit board 30. The fixing portion 253 is provided near the center of the cooling plate 21 in the X direction. One of the two fixing portions 253 is provided near the wall 2212, and the other is provided near the wall 2213.

[0032] The fixing portion 25 includes fixing portions 254, 255 provided on the rear surface 21b. The fixing portion 254 is a portion for screwing together the back plate 50 (502, 503) and the circuit board 40 (401, 402) corresponding to the circuit board 40. Four of the fixing portions 254 are provided at positions overlapping the circuit board 401 in a plan view, and the other four fixing portions 254 are provided at positions overlapping the circuit board 402. Of the fixing portions 254 corresponding to the circuit board 401, two are provided side by side in the X direction between the wall portion 2222 and the flow path 24, and the other two are provided side by side in the X direction between the wall portion 2223 and the flow path 24. The same applies to the fixing portion 254 corresponding to the circuit board 402.

[0033] The fixing portions 255 are portions for fastening the cover 62 and the circuit board 40 with screws. The fixing portions 255 are provided outside the wall portion 222. Of the eight fixing portions 255, four are provided at positions overlapping with the four corners of the circuit board 401, and the other four are provided at positions overlapping with the four corners of the circuit board 402. The four fixing portions 255 are provided near the four corners of the main body portion 211, and the other four fixing portions 255 are provided near the center of the cooling plate 21 in the X direction.

[0034] <Circuit board> FIG. 9 is a plan view showing a circuit board arranged on one side of a cooling plate. FIG. 10 is a plan view showing a circuit board arranged on the back side of a cooling plate. In FIGS. 9 and 10, for convenience, the shield cover is indicated by a dashed line to show the electronic components covered by the shield cover. FIG. 11 is a diagram showing an electronic device with the cover on one side omitted. FIG. 12 is a diagram showing the same components as in FIG. 11 but with some of the elements constituting the circuit board omitted. FIG. 12 shows the positional relationship between the wall, electronic components, lands, and back plate on the one side. FIG. 13 is a diagram showing the same components as in FIG. 13 but with some of the elements constituting the circuit board omitted. FIG. 14 is a diagram showing the same components as in FIG. 13 but with some of the elements constituting the circuit board omitted. FIG. 14 shows the positional relationship between the wall, electronic components, lands, and back plate on the back side. In FIGS. 9, 10, 12, and 14, for convenience, only lands corresponding to the wall provided on the surface facing the cooling plate are shown as conductors of the printed circuit board. For example, lands corresponding to the shield cover are omitted. Also, only a portion of the electronic components is shown. The shield cover is omitted from Figures 12 and 14. For convenience, the solder resist is also omitted.

[0035] As described above, the circuit board 30 is disposed on one surface 21a of the cooling plate 21. The circuit board 40 is disposed on the back surface 21b of the cooling plate 21. The circuit boards 30, 40 are disposed so as to sandwich the cooling plate 21 in the Z direction. The circuit board 30 is a base board, and the circuit board 40 is an extension board. The circuit board 30 is a board on which functions that do not change depending on the vehicle model or specifications, i.e., common functions, are implemented. The circuit board 40 is a board for extending the functions of the base board. The circuit board 40 is a board on which additional functions depending on the vehicle model or specifications are implemented. The circuit board 40 is replaceable depending on the vehicle model or specifications.

[0036] For example, the circuit board 30 is equipped with a primary power supply system, an IVI function, etc. IVI is an abbreviation for In-Vehicle Infotainment. The circuit board 40 is equipped with an AD function or an ADAS function. AD is an abbreviation for Autonomous driving system. ADAS is an abbreviation for Advanced Driving Assistant System.

[0037] The circuit board 30 includes a printed circuit board 31, electronic components 32, and connectors 33 and 34. The planar shape of the printed circuit board 31 is not particularly limited. The illustrated printed circuit board 31 has a substantially rectangular planar shape. In the electronic device 10, the thickness direction of the printed circuit board 31 is substantially parallel to the Z direction.

[0038] The printed circuit board 31 has an insulating substrate 311 and a conductor. The insulating substrate 311 is formed using an electrically insulating material such as resin. The insulating substrate 311 may be made of, for example, a material containing only resin, or a material combining resin with glass cloth, nonwoven fabric, or the like. The conductor is formed using a metal material with good conductivity, such as Cu. The conductor includes a wiring layer. The wiring layer may be referred to as wiring, a wiring pattern, a conductor pattern, or the like. The wiring layer may be formed, for example, by patterning a metal foil, or by printing. The wiring layers are arranged in multiple layers on the insulating substrate.

[0039] The conductor may include a via conductor or a through-hole land in addition to the wiring layer. A via conductor is formed by disposing a conductor such as plating in a through-hole (via) formed in an insulating layer that constitutes the insulating substrate 311. The via conductor electrically connects, for example, wiring layers arranged on different layers. A through-hole land is formed on the wall surface of a through-hole that penetrates the printed circuit board 31 in the Z direction. The through-hole land may be formed around the opening as well as on the wall surface of the through-hole.

[0040] The conductor has lands, which are electrode portions of the wiring layer, on the surface layer of the printed circuit board 31. In the illustrated electronic device 10, the conductor includes lands 312 and 313 that provide a reference potential (ground potential) on the circuit board 30. As will be described later, the conductor includes via conductors and a ground layer disposed inside the insulating substrate 311. As will be described in detail later, the lands 312 and 313 are connected to the ground layer through the via conductors. The land 312 is electrically connected to the corresponding wall portion 221 via a gasket or the like. The land 313 is electrically connected to the cover 61 via a gasket or the like.

[0041] The land 312 is provided on the surface facing the cooling plate 21. The land 312 is provided corresponding to the wall portion 221 on the side of the first surface 21a of the cooling plate 21. The land 312 is provided along the outer periphery of the printed circuit board 31 excluding the portion where the connector 34 is mounted. The land 312 has a ring shape that is approximately rectangular in plan view.

[0042] As shown in FIG. 12 , the land 312 is provided so as to overlap the wall portion 221 in a plan view. The land 312 has lands 3121, 3122, and 3123. The land 3121 is provided near both ends of the printed circuit board 31 in the X direction. One of the lands 3121 is located near the side plate portion 212, and the other land 3121 is located near the side plate portion 213. The land 3121 extends approximately in the Y direction. The lands 3122 and 3123 are continuous with the land 3121. The land 3122 is provided near one end of the printed circuit board 31 in the Y direction, and the land 3123 is provided on the opposite side of the land 3122, near the mounting portion of the connector 34. The lands 3122 and 3123 extend approximately in the X direction.

[0043] The land 313 is provided on the surface opposite to the surface facing the cooling plate 21. Like the land 312, the land 313 is provided along the outer periphery of the printed circuit board 31 excluding the portion where the connector 34 is mounted. The land 313 has a ring shape that is approximately rectangular in plan view.

[0044] The printed circuit board 31 has through holes 35 for fixing. The through holes 35 include through holes 351, 352, and 353. The through hole 351 is a through hole for fixing the back plate 50 (501) and the circuit board 30 to the cooling plate 21. The through hole 351 is provided so as to overlap with the fixing portion 251 in a plan view. Two of the four through holes 351 are provided closer to the land 3122 than the center of the printed circuit board 31 in the Y direction and are aligned in the X direction. The other two are provided closer to the land 3123 than the center of the printed circuit board 31 in the Y direction and are aligned in the X direction.

[0045] The through holes 352 are used to fix the cover 61 and the circuit board 30 to the cooling plate 21. The through holes 352 are provided so as to overlap the fixing portions 252 in a plan view. The through holes 352 are provided outside the lands 312. The four through holes 352 are provided at the four corners of the printed circuit board 31. The through holes 353 are used to fix the circuit board 30 to the cooling plate 21. The through holes 353 are provided so as to overlap the fixing portions 253 in a plan view. One of the two through holes 353 is provided near the land 3122, and the other is provided near the land 3123. Through hole lands 314 are provided on the wall surfaces and around the openings of the through holes 351 and 353.

[0046] The electronic components 32 are mounted on the printed circuit board 31. A plurality of electronic components 32 are mounted on the printed circuit board 31. The electronic components 32 form a circuit together with the above-mentioned conductors. The electronic components 32 are arranged at least on the surface of the printed circuit board 31 facing the cooling plate 21. A primary power supply circuit (not shown) is formed on the circuit board 30 by the conductors and the electronic components 32.

[0047] In the illustrated electronic device 10, digital circuits that generate noise and / or are affected by noise, such as a processor, memory, and clock oscillator, are mounted in the central region of the printed circuit board 31. Noise becomes a problem particularly at higher operating frequencies. Heat-generating components that generate heat during operation are mounted in the central region. The electronic components 32 mounted in the central region include electronic components 321, 322, and 323. The electronic component 321 includes a processor and memory. The processor implements multiple functional units by executing a control program stored in memory. The electronic component 321 is, for example, an SoC. SoC is an abbreviation for System on Chip. A microcomputer or the like may also be used as the electronic component 321. The electronic component 322 is a memory such as flash or ROM. ROM is an abbreviation for Read Only Memory. The electronic component 323 is a power supply IC that constitutes a secondary power supply circuit. The number of each of the electronic components 321, 322, and 323 is not particularly limited. There may be only one or more. At least one of the heat generating components may be connected to the cooling plate 21 via a thermally conductive member such as a TIM.

[0048] The electronic component 32 mounted in the area between the central area and the land 3122 includes an electronic component 324. The electronic component 324 is a communication IC for high-speed data communication between the circuit boards 30 and 40. The electronic component 324 is, for example, a PCI-e switch. PCI-e is an abbreviation for Peripheral Component Interconnect-express. The electronic component 32 mounted in the area between the central area and the land 3123 includes an electronic component 325. The electronic component 325 is a communication IC for communicating with a device (external device) other than the electronic device 10. The electronic component 325 is used for high-speed communication such as CAN, LVDS, GVIF, and Ethernet. CAN, GVIF, and Ethernet are registered trademarks. CAN is an abbreviation for Controller Area Network. LVDS is an abbreviation for Low Voltage Differential Signaling. GVIF is an abbreviation for Gigabit Video Interface. The electronic components 325 may include, for example, a CAN transceiver, an Ethernet PHY, an Ethernet switch, and the like.

[0049] The connectors 33 and 34 are mounted on the printed circuit board 31. The connector 33 is a connector for electrically connecting the circuit board 30 and the circuit board 40. The connector 33 is mounted at a position overlapping the through hole 23 in a plan view. The connector 33 is mounted in the same region as the electronic component 324. The connector 34 is a connector for electrically connecting an external device to the circuit board 30. The connector 34 includes a connector used for the high-speed communication described above. The connector 34 is disposed between the end of the printed circuit board 31 and the land 3123 in the Y direction.

[0050] The circuit board 30 further includes a shield cover 36. The shield cover 36 is a metal plate made of a material containing Cu, such as nickel silver. The shield cover 36 is mounted on the printed circuit board 31. The shield cover 36 is electrically connected to corresponding lands, as described below. The shield cover 36 is disposed on the surface of the printed circuit board 31 facing the cooling plate 21 so as to cover electronic components 32 that generate noise and / or are affected by noise. In the illustrated electronic device 10, the shield cover 36 is disposed in the central region and covers electronic components 321, 322, and 323. The detailed structure of the shield cover 36 will be described later.

[0051] The circuit board 40 has a similar configuration to the circuit board 30. The circuit board 40 includes a printed circuit board 41, electronic components 42, and connectors 43 and 44. The illustrated electronic device 10 includes two circuit boards 401 and 402 as the circuit board 40. The two circuit boards 401 and 402 are arranged side by side in the X direction. Each of the circuit boards 401 and 402 has approximately half the size of the circuit board 30 in a plan view. The circuit boards 401 and 402 have, for example, a substantially rectangular shape in plan view. In the electronic device 10, the thickness direction of the printed circuit board 41 is approximately parallel to the Z direction.

[0052] In each circuit board 40, the printed circuit board 41 has an insulating substrate 411 and a conductor. The conductor has a land on the surface layer of the printed circuit board 41. In the illustrated electronic device 10, the conductor includes lands 412 and 413 that provide a ground potential. As will be described later, the conductor includes via conductors and a ground layer disposed inside the insulating substrate 411. As will be described in detail later, the lands 412 and 413 are connected to the ground layer through the via conductors. The land 412 is electrically connected to the corresponding wall portion 222 via a conductive gasket or the like. The land 413 is electrically connected to the cover 62 via a gasket or the like.

[0053] The land 412 is provided on the surface facing the cooling plate 21. The land 412 is provided corresponding to the wall portion 222 on the back surface 21b side of the cooling plate 21. The land 412 is provided along the outer periphery of the printed circuit board 41 excluding the mounting portion of the connector 44. The land 412 has a ring shape that is approximately rectangular in plan view.

[0054] As shown in FIG. 14 , the land 412 is provided so as to overlap the wall portion 222 in a plan view. The land 412 has lands 4121, 4122, 4123, and 4124. The land 4124 is arranged along the adjacent side of each of the two circuit boards 401 and 402. The land 4124 extends approximately in the Y direction. The land 4121 is arranged along the side of each of the circuit boards 401 and 402 opposite to the side to which the land 4124 extends. The land 4121 extends approximately in the Y direction. In each of the circuit boards 401 and 402, the land 4121 is provided near one end of the printed circuit board 41 in the X direction, and the land 4124 is provided near the other end.

[0055] The lands 4122 and 4123 are continuous with the lands 4121 and 4124. The land 4122 is provided near one end in the Y direction of each printed circuit board 41, and the land 4123 is provided on the opposite side of the land 4122 and in the vicinity of the mounting portion of the connector 44. The lands 4122 and 4123 extend generally in the X direction.

[0056] The land 413 is provided on the surface opposite to the surface facing the cooling plate 21. The land 413 is provided along the outer periphery of the printed circuit board 41 excluding the portion where the connector 44 is mounted. The land 413 has a ring shape that is approximately rectangular in plan view.

[0057] The printed circuit board 41 has through holes 45 for fixing. The through holes 45 include through holes 451 and 452. The through hole 451 is a through hole for fixing the corresponding back plate 50 and circuit board 40 to the cooling plate 21. The through hole 451 is provided so as to overlap the fixing portion 254 in a plan view. In each printed circuit board 41, two of the four through holes 451 are provided closer to the land 4122 than the center of the printed circuit board 41 in the Y direction and are aligned in the X direction. The other two are provided closer to the land 4123 than the center of the printed circuit board 41 in the Y direction and are aligned in the X direction.

[0058] The through holes 452 are used to fix the cover 62 and the circuit board 40 to the cooling plate 21. The through holes 452 are provided so as to overlap the fixing portions 255 in a plan view. The through holes 452 are provided outside the lands 412. Four through holes 452 are provided at the four corners of the printed circuit board 41. Through hole lands 414 are provided on the wall surfaces of the through holes 451 and around the openings.

[0059] The electronic components 42 are mounted on the printed circuit board 41. A plurality of electronic components 42 are mounted on the printed circuit board 41. The electronic components 42 are arranged at least on the surface of the printed circuit board 41 that faces the cooling plate 21. Of the two circuit boards 40, for the circuit board 402, only the electronic component 421 is shown as the electronic component 42 for convenience.

[0060] The central region of the printed circuit board 41 is equipped with digital circuits that generate noise and / or are affected by noise, such as a processor, memory, and clock oscillator. Heat-generating components that generate heat during operation are also mounted in the central region. The electronic components 42 mounted in the central region include electronic components 421, 422, and 423. The electronic component 421 includes a processor, memory, and the like. The electronic component 421 is, for example, an SoC. A microcomputer or the like may also be used as the electronic component 421. The electronic component 422 is a memory such as a flash memory or a ROM. The electronic component 423 is a power supply IC that constitutes a secondary power supply circuit. At least one of the heat-generating components arranged in the central region may be connected to the flow path cover 28 of the cooler 20 via a thermally conductive member such as a TIM. The number of each of the electronic components 421, 422, and 423 is not particularly limited. There may be only one or more electronic components.

[0061] The electronic component 42 mounted in the area between the central area and the land 4123 includes an electronic component 424. The electronic component 424 is a communication IC for communicating with an external device. The electronic component 424 is, for example, a serializer and deserializer used for high-speed communication such as GVIF.

[0062] The connectors 43 and 44 are mounted on the printed circuit board 41. The connector 43 is a connector for electrically connecting the circuit board 30 and the circuit board 40. The connector 43 is mounted at a position overlapping the through hole 23 in a plan view. The connector 43 is disposed in the region between the central region and the land 4122. The connectors 33 and 43 are sometimes referred to as BtoB connectors. A flat wire or a flexible substrate may be used instead of the connectors 33 and 43. The connectors 34 and 44 correspond to the connection portion. The connector 44 is a connector for electrically connecting the circuit board 40 and an external device. The connectors include the connector used for high-speed communication described above.

[0063] The circuit board 40 further includes a shield cover 46. Like the shield cover 36, the shield cover 46 is a metal plate formed using a material containing Cu, such as nickel silver. The shield cover 46 is mounted on the printed circuit board 41. The shield cover 46 is electrically connected to corresponding lands, as described below. The shield cover 46 is disposed on the surface of the printed circuit board 41 facing the cooling plate 21 so as to cover electronic components 42 that generate noise and / or are affected by noise. In the illustrated electronic device 10, the shield cover 46 is disposed in the central region and covers electronic components 421 and the like. The detailed structure of the shield cover 46 will be described later.

[0064] <Backplate> As shown in FIGS. 5 to 7 and 11 to 14, the backplate 50 presses the circuit boards 30 and 40 against the cooling plate 21. The backplate 50 has spring properties, and presses the circuit boards 30 and 40 against the cooling plate 21 (cooler 20) by the reaction force due to spring deformation. The backplate 50 is disposed on the surface of the circuit boards 30 and 40 opposite the surface facing the cooling plate 21, i.e., on the back side. The backplate 50 includes backplates 501, 502, and 503. The backplate 501 is disposed on the circuit board 30. The backplate 502 is disposed on the circuit board 401. The backplate 503 is disposed on the circuit board 402. The backplates 501, 502, and 503 have, for example, a common structure with each other.

[0065] The backplate 50 has a frame portion 51 and leg portions 52. The frame portion 51 has a generally rectangular ring shape in a plan view. The frame portion 51 of the backplate 501 is provided so as to surround the electronic component 321 in a plan view. The frame portions 51 of the backplates 502 and 503 are provided so as to surround the corresponding electronic component 421 in a plan view. The leg portions 52 extend from the four corners of the frame portion 51. The backplate 50 has four leg portions 52. Fixing holes for screws 70 are provided at the ends of the leg portions 52. The distance between the ends of two leg portions 52 aligned in the X direction is wider than the distance between the ends connected to the frame portion 51. The leg portions 52 extend diagonally from the frame portion 51. When screwed together, the frame portion 51 and the leg portions 52 press the corresponding circuit boards 30 and 40 against the cooling plate 21 (cooler 20) by spring reaction force.

[0066] In a plan view, the frame portion 51 of the backplate 501 is provided at a position overlapping the central region of the printed circuit board 31. In a plan view, the two leg portions 52 extend from the central region to the region between the central region and the land 3122. In a plan view, the other two leg portions 52 extend from the central region to the region between the central region and the land 3123. The screws 70 attached to the leg portions 52 of the backplate 501 are inserted through the through holes 351 of the printed circuit board 31 and fastened to the fixing portions 251 of the cooling plate 21.

[0067] In a plan view, the frame portion 51 of the backplate 502 is provided at a position overlapping the central region of the printed circuit board 41. In a plan view, the two leg portions 52 extend from the central region to the region between the central region and the land 4122. In a plan view, the other two leg portions 52 extend from the central region to the region between the central region and the land 4123. The screws 70 attached to the leg portions 52 of the backplate 501 are inserted through the through holes 451 of the printed circuit board 41 and fastened to the fixing portions 254 of the cooling plate 21. The backplate 503 is similar to the backplate 502.

[0068] <Case> The housing 60 is made of a material capable of electromagnetic shielding. The housing 60 is made of a metal material such as aluminum or iron. Instead of a metal material, the housing 60 may be made of a metal material and a resin material. For example, the housing 60 may be made of a resin molded body with metal plating on the inner surface, or a resin mixed with conductive particles. In the illustrated electronic device 10, the housing 60 is made of a metal material.

[0069] As shown in FIGS. 1 to 5 , the housing 60 includes covers 61 and 62 and side plates 63 and 64. The covers 61 and 62 form the outer shell of the electronic device 10 in the Z direction. The cover 61 is disposed on the rear side of the circuit board 30. The cover 61 covers the back plate 501 and the circuit board 30. The cover 61 is provided so as to enclose the back plate 501 and most of the circuit board 30 in a plan view. In a plan view, a portion of the connector 34 is located outside the cover 61. The cover 61 has a through hole 610. The screw 70 is inserted through the through hole 610 and the through hole 352 of the printed circuit board 31 and fastened to the fixing portion 252 of the cooling plate 21.

[0070] The cover 62 is disposed on the rear side of the circuit board 40 (401, 402). The cover 62 covers the back plates 502, 503 and the circuit boards 401, 402. The cover 62 is provided so as to enclose the back plates 502, 503 and most of the circuit boards 401, 402 in a plan view. In a plan view, a portion of the connector 44 is located outside the cover 62. The cover 62 has a through hole 620. The screw 70 is inserted through the through hole 620 and the through hole 452 of the printed circuit board 41 and fastened to the fixing portion 255 of the cooling plate 21.

[0071] The side plates 63, 64 form the outer casing of the electronic device 10 in the Y direction. The side plate 63 is disposed on the connectors 34, 44 side. The side plate 63 has through holes 630, 631. The screws 70 are inserted through the through holes 630 and fastened to the fixing portions of the cooling plate 21. The through holes 631 are provided corresponding to the connectors 34, 44 so that portions of the connectors 34, 44 are exposed to the outside of the electronic device 10. The side plate 64 is disposed on the opposite side of the connectors 34, 44 in the Y direction. The side plate 64 has through holes 640. The screws 70 are inserted through the through holes 640 and fastened to the fixing portions of the cooling plate 21. As described above, the side plate portions 212, 213 of the cooling plate 21 also function as the housing 60. The side plate portions 212, 213 form the outer casing of the electronic device 10 in the X direction.

[0072] <Electromagnetic shield and cooling structure> FIG. 15 is a cross-sectional view taken along line XV-XV in FIG. 1. For convenience, the gasket and TIM are omitted from FIG. 15. FIG. 16 is a cross-sectional view showing an electromagnetic shield configured in an electronic device. FIG. 16 is an image diagram showing a heat-generating component, a through hole, and components of the electromagnetic shield in a common cross section. FIG. 17 is a plan view showing elements of the electromagnetic shield on a circuit board.

[0073] A coolant 29 flows through the flow paths 24 of the cooling plate 21. The electronic device 10 includes an electromagnetic shield 80. The electromagnetic shield 80 may be arranged to cover specific circuit elements configured on the circuit board 30 that are noise sources, or may be arranged to cover specific circuit elements that are desired to suppress the effects of external noise. The electromagnetic shield 80 includes lands 315, multiple via conductors 316, a ground layer 317, and a shield cover 36. In the illustrated electronic device 10, the electromagnetic shield 80 houses electronic components 32 mounted in the central region of the printed circuit board 31, such as an electronic component 321 (SoC) and an electronic component 322 (memory).

[0074] 16, the electronic device 10 includes a conductive gasket 71 and a TIM 72. The gasket 71 is provided, for example, along the wall portion 221. The gasket 71 is provided over the entire length of the wall portion 221. The gasket 71 is interposed between the wall portions 2211, 2212, and 2213 and the lands 3121, 3122, and 3123, and electrically connects the wall portions 2211, 2212, and 2213 to the lands 3121, 3122, and 3123. The annular wall portion 221 and the annular land 312 are electrically connected over the entire length.

[0075] As shown in FIG. 17 , via conductors 316 electrically connect the land 315 and the ground layer 317. The ground layer 317 is a so-called solid ground. The ground layer 317 is disposed over most of the surface. In the illustrated electronic device 10, the ground layer 317 is an inner-layer ground disposed inside the insulating substrate 311. A ground layer disposed on the back surface may be used instead of the inner-layer ground. Multiple via conductors 316 are disposed at predetermined intervals along the annular land 315. The spacing between the via conductors 316 is preferably equal to or less than half the wavelength of the frequency of the noise to be blocked. When noise of multiple frequencies is to be blocked, the spacing should be equal to or less than half the wavelength of the lowest frequency. More preferably, the spacing should be equal to or less than a quarter wavelength of the frequency of the noise to be blocked. Each element constituting the electromagnetic shield 80 is fixed to a predetermined potential (ground potential).

[0076] As described above, the shield cover 36 covers the electronic components 32 arranged in the central region. The shield cover 36 is electrically connected to the lands 315. In the illustrated electronic device 10, the shield cover 36 has a top wall 361 and a side wall 362. The top wall 361 is arranged between the electronic components 32 and the cooling plate 21 in the Z direction. The top wall 361 faces the upper surface of the electronic components 32. The top wall 361 has, for example, a substantially rectangular shape in plan view. The side wall 362 is continuous with the outer peripheral edge of the top wall 361. The side wall 362 has a cylindrical shape. The side wall 362 surrounds the electronic components 32 in the central region in a plan view. The side wall 362 extends in the Z direction. The lower end of the side wall 362 is connected to the lands 315. The lower end is connected to the lands 315 by, for example, soldering. The lower end of the annular side wall 362 and the annular land 315 are electrically connected over their entire length.

[0077] The TIM 72 transfers heat from the heat-generating components mounted on the printed circuit board 31 to other components. The TIM 72 is interposed between the top wall 361 of the shield cover 36 and the cooling plate 21. The TIM 72 is interposed between the top wall 361 and at least a portion of the electronic component 32 housed in the shield cover 36 (electromagnetic shield 80). In the illustrated electronic device 10, the TIM 72 is provided at a position overlapping the electronic component 321 (SoC) in a plan view. The TIM 72 is interposed between the top wall 361 and the cooling plate 21 and is in contact with the top wall 361 and the cooling plate 21. The TIM 72 is interposed between the upper surface of the electronic component 321 and the top wall 361 and is in contact with the electronic component 321 and the top wall 361. The TIM 72 thermally connects the shield cover 36 and the cooling plate 21. The TIM 72 thermally connects the electronic component 321 and the shield cover 36. The TIM 72 thermally connects the electronic component 321 and the cooling plate 21 .

[0078] The circuit board 30 further has via conductors 318. The via conductors 318 electrically connect the lands 312 and 313. The via conductors 318 are provided at predetermined intervals along the land 312, similar to the via conductors 316. The via conductors 318 electrically connect the lands 312 and 313 through the ground layer 317. The land 312 is electrically connected to the wall portion 221 via a gasket 71. The land 312 is electrically connected to the wall portion 221 over its entire length. The cover 61 is electrically connected to the land 313 via the gasket 71. The gasket 71 is provided over the entire length of the land 313. The annular land 313 is electrically connected to the cover 61 over its entire length. The via conductors 318 and the cover 61 are fixed to a ground potential.

[0079] The electronic device 10 further includes an electromagnetic shield 81. The electromagnetic shield 81 may be arranged to cover specific circuit elements that are noise sources and are configured on the circuit board 40, or may be arranged to cover specific circuit elements that are desired to suppress the effects of external noise. The configuration of the electromagnetic shield 81 is similar to that of the electromagnetic shield 80. The electromagnetic shield 81 includes lands 415, multiple via conductors 416, a ground layer 417, and a shield cover 46. In the illustrated electronic device 10, the electromagnetic shield 81 houses electronic components 42 mounted in the central region of the printed circuit board 41, such as an electronic component 421 (SoC) and an electronic component 422 (memory).

[0080] As described above, the gasket 71 is provided along the wall portion 22. The gasket 71 is interposed between the wall portions 2221, 2222, 2223, 2224 and the lands 4121, 4122, 4123, 4124, and electrically connects the wall portions 2221, 2222, 2223, 2224 and the lands 4121, 4122, 4123, 4124. The annular wall portion 222 and the annular land 412 are electrically connected over their entire length.

[0081] Similar to the via conductor 316, the via conductor 416 electrically connects the land 415 and the ground layer 417. The ground layer 417 is a solid ground. The ground layer 417 is disposed over most of the surface. In the illustrated electronic device 10, the ground layer 417 is an inner-layer ground disposed inside the insulating substrate 411. A ground layer disposed on the back surface may be used instead of the inner-layer ground. The multiple via conductors 416 are disposed at predetermined intervals along the annular land 415. The spacing between the via conductors 416 is preferably equal to or less than half the wavelength of the frequency of the noise to be blocked. When noise of multiple frequencies is to be blocked, the spacing should be equal to or less than half the wavelength of the lowest frequency. More preferably, the spacing should be equal to or less than a quarter wavelength of the frequency of the noise to be blocked. Each element constituting the electromagnetic shield 81 is fixed to a predetermined potential (ground potential).

[0082] As described above, the shield cover 46 covers the electronic components 42 arranged in the central region. The shield cover 46 is electrically connected to the lands 415. In the illustrated electronic device 10, the shield cover 46 has a structure similar to that of the shield cover 36. The shield cover 46 has a top wall 461 and a side wall 462. The top wall 461 is arranged between the electronic components 42 and the cooling plate 21. The top wall 461 has, for example, a substantially rectangular shape in plan view. The side wall 462 is continuous with the outer peripheral edge of the top wall 461. The side wall 462 has a cylindrical shape. The side wall 462 surrounds the electronic components 42 in the central region in a plan view. The side wall 462 extends in the Z direction. The lower end of the side wall 462 is connected to the lands 315. The lower end is connected to the lands 415 by, for example, soldering. The lower end of the annular side wall 462 and the annular land 415 are electrically connected over their entire length.

[0083] The TIM 72 transfers heat from heat-generating components mounted on the printed circuit board 41 to other components. The TIM 72 is interposed between the top wall 461 of the shield cover 46 and the cooling plate 21. The TIM 72 is interposed between the top wall 461 and at least a portion of the electronic component 42 housed in the shield cover 46 (electromagnetic shield 81). In the illustrated electronic device 10, the TIM 72 is provided at a position overlapping the electronic component 421 (SoC) in a plan view. The TIM 72 is interposed between the top wall 461 and the cooling plate 21 and is in contact with the top wall 461 and the cooling plate 21. The TIM 72 is interposed between the upper surface of the electronic component 421 and the top wall 461 and is in contact with the electronic component 421 and the top wall 461. The TIM 72 thermally connects the shield cover 46 and the cooling plate 21. The TIM 72 thermally connects the electronic component 421 and the shield cover 46. The TIM 72 thermally connects the electronic component 421 and the cooling plate 21 .

[0084] The circuit board 40 further has a via conductor 418. The via conductor 418 electrically connects the land 412 and the land 413. The via conductor 418 is provided at predetermined intervals along the land 412, similar to the via conductor 416. The via conductor 418 electrically connects the land 412 and the land 413 through a ground layer 417. The land 412 is electrically connected to the wall portion 222 via a gasket 71. The land 412 is electrically connected to the wall portion 222 over its entire length. The cover 62 is electrically connected to the land 413 via the gasket 71. The gasket 71 is provided over the entire length of the land 413. The annular land 413 is electrically connected to the cover 62 over its entire length. The via conductor 418 and the cover 62 are fixed to a ground potential.

[0085] <Summary of the First Embodiment> According to this embodiment, the circuit board 30 is disposed on one surface 21a of the cooling plate 21, and the circuit board 40 is disposed on the back surface 21b. The circuit boards 30, 40 are electrically connected via the through-holes 23 of the cooling plate 21. This simplifies the connection structure of the circuit boards 30, 40.

[0086] Providing through holes in the cooling plate may cause noise generated by an electronic component mounted on one of the circuit boards to affect electronic components mounted on another of the circuit boards. In this embodiment, the electronic device 10 includes an electromagnetic shield 80. The electromagnetic shield 80 includes a shield base, a ground conductor, and a shield cover 36. In the illustrated electronic device 10, the shield cover 36 is provided to cover electronic components 32, such as electronic component 321 (SoC) and electronic component 322 (memory), mounted in the central region of the printed circuit board 31 in a plan view. The shield cover 36 is provided to house the electronic components 32. The electronic components 321 and 322 correspond to the first electronic component. The circuit board 30 corresponds to the first circuit board.

[0087] Lands 315 and via conductors 316 formed on circuit board 30 provide a reference potential (ground potential) and are arranged to surround electronic components 321 and 322 in a plan view. Lands 315 and via conductors 316 correspond to the ground conductors. Ground layer 317 formed on circuit board 30 is arranged to enclose lands 315 and via conductors 316 in a plan view. Shield cover 36 is electrically connected to ground layer 317 via lands 315 and via conductors 316. Ground layer 317 corresponds to a shield base.

[0088] In this manner, the electronic component 321 (SoC) and the electronic component 322 (memory) are disposed inside the electromagnetic shield 80. They are disposed in an electromagnetically shielded space defined by the electromagnetic shield 80. The electromagnetic shield 80 functions as a noise return path. The electromagnetic shield 80 blocks noise through its shielding effect. The through-hole 23 is provided outside the electromagnetic shield 80. This prevents noise generated by the electronic components 321 and 322 from affecting the circuit board 40, particularly the electronic component 421 (SoC) and the electronic component 422 (memory), through the through-hole 23. This prevents noise generated by the electronic components 421 and 422 from affecting the circuit board 40, particularly the electronic components 321 and 322, through the through-hole 23. The circuit board 40 corresponds to the second circuit board. The electronic components 421 and 422 correspond to the second electronic components. Note that the electronic device 10 may include only the electromagnetic shield 81. In this case, the circuit board 40 corresponds to the first circuit board, and the electronic components 421 and 422 correspond to the first electronic components.

[0089] Furthermore, the electromagnetic shield 80 is constructed using the shield cover 36 mounted on the printed circuit board 31. Because the cooling plate 21 is not used as an element of the electromagnetic shield 80, the structure of the cooling plate 21 can be simplified. The shield cover 36 is one of the components mounted on the printed circuit board 31, and can take various forms. Therefore, compared to a configuration in which the cooling plate 21 is one of the elements of the electromagnetic shield 80, the design freedom can be improved.

[0090] As illustrated, the electronic device 10 may include a thermally conductive member that transfers heat generated by the first electronic component. In the illustrated electronic device 10, the TIM 72 corresponds to the thermally conductive member. The TIM 72 transfers heat generated by, for example, the electronic component 321. This can improve the heat dissipation performance of the electronic component 321 while suppressing the effects of noise.

[0091] As illustrated, the TIM 72 may be interposed between the top wall 361 of the shield cover 36 and the cooling plate 21. In addition, the TIM 72 may be interposed between the electronic component 321 (first electronic component) and the top wall. When the TIM 72 is disposed above and below the top wall 361, heat generated by the electronic component 321 is transferred to the cooling plate 21 via, for example, the TIM 72, the top wall 361 of the shield cover 36, and the TIM 72. Therefore, the heat dissipation performance of the electronic component 321 can be further improved while suppressing the influence of noise.

[0092] As illustrated, the electronic device 10 may include a back plate 50 (501) that presses the circuit board 30 against the cooling plate 21. The back plate 501 may be disposed across the shield cover 36 in a plan view and fixed to the cooling plate 21 at a position that does not overlap with the shield cover 36. This can prevent the circuit board 30 (printed circuit board 31) from warping due to heat. In particular, in a configuration that includes the TIM 72, it can prevent a gap from forming between the TIM 72 and the shield cover 36 and / or the cooling plate 21, which would otherwise reduce heat dissipation.

[0093] As shown in the example, the ground layer 317 may be used as the shield base. Alternatively, the cover 61 constituting the housing 60 may be used as the shield base. Using the ground layer 317 can simplify the configuration. The ground layer 317 may be disposed on an inner layer of the printed circuit board 31, or on the surface opposite to the surface facing the cooling plate 21.

[0094] In the illustrated electronic device 10, the cover 61 is also electrically connected to the land 315 via the via conductor 318, the ground layer 317, and the via conductor 316. The electronic device 10 includes an electromagnetic shield including the shield cover 36, the land 315, the via conductor 316, the ground layer 317, the via conductor 318, the land 313, and the cover 61. The electronic device 10 also includes an electromagnetic shield including the cooling plate 21, the wall 221, the land 312, the via conductor 318, the ground layer 317, the via conductor 318, the land 313, and the cover 61. This can suppress the effects of external noise. Furthermore, it can suppress noise radiation outside the electronic device 10.

[0095] As illustrated, circuit board 30 may include electronic component 321 (SoC) as a first electronic component disposed inside electromagnetic shield 80. This can prevent noise generated by the SoC from affecting circuit board 40 through through-hole 23. It can also prevent noise generated by circuit board 40 from affecting the SoC. In this way, the SoC can be cooled by cooling plate 21 while suppressing the effects of noise.

[0096] <Modification> The arrangement of the thermally conductive member TIM 72 is not limited to the above example. For example, as shown in Fig. 18, the TIM 72 may be arranged only between the top wall 361 of the shield cover 36 and the cooling plate 21. In this structure, heat from the electronic component 321 is conducted to the cooling plate 21 via the circuit board 30, the shield cover 36, and the TIM 72. This makes it possible to improve the heat dissipation performance of the electronic component 321 while suppressing the effects of noise.

[0097] 19, the TIM 72 may be disposed only between the top wall 361 of the shield cover 36 and the electronic component 321. In this structure, heat from the electronic component 321 is transferred to the TIM 72, the shield cover 36, and the circuit board 30. The circuit board 30 is fixed to the cooling plate 21, and the heat from the electronic component 321 is transferred to the cooling plate 21 via the circuit board 30. The electronic component 321 can dissipate heat from both sides. This improves the heat dissipation performance of the electronic component 321 while suppressing the effects of noise. FIGS. 18 and 19 show a modified example. FIGS. 18 and 19 show only the periphery of the electronic component 321 in the electronic device 10.

[0098] Although the electronic device 10 has been described as including two circuit boards 40 (401, 402), the present invention is not limited to this. The electronic device 10 may include only one circuit board 40, or may include three or more circuit boards 40. For example, if there is one circuit board 40, there may be only one through-hole 23.

[0099] Each of the via conductors 316, 318, 416, and 418 may be a single via conductor, or may be a plurality of via conductors connected in the Z direction.

[0100] (Second embodiment) This embodiment is a modification based on the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the TIMs 72 located above and below the top wall 361 are separated by the top wall 361. Alternatively, the TIMs 72 located above and below the top wall 361 may be configured to be continuous.

[0101] FIG. 20 is a plan view showing the periphery of an electronic component 321 in an electronic device 10 according to the second embodiment. FIG. 20 corresponds to FIGS. 18 and 19. As shown in FIG. 20, the shield cover 36 has at least one communication hole 363 in a top wall 361. The communication hole 363 penetrates the top wall 361. The communication hole 363 has a diameter that is equal to or smaller than ½ the wavelength of the frequency of the noise to be blocked. More preferably, the communication hole 363 has a diameter that is equal to or smaller than ¼ the wavelength of the frequency of the noise to be blocked. In the example electronic device 10, the shield cover 36 has multiple communication holes 363.

[0102] The TIM 72 (thermal conductive member) interposed between the electronic component 321 and the cooling plate 21 has a first thermal conductive portion 721, a second thermal conductive portion 722, and a communicating portion 723. The first thermal conductive portion 721 is interposed between the top wall 361 and the cooling plate 21 and is in contact with the top wall 361 and the cooling plate 21. The second thermal conductive portion 722 is interposed between the top wall 361 and the electronic component 321 and is in contact with the top wall 361 and the electronic component 321. The communicating portion 723 is disposed in the communicating hole 363. One end of the communicating portion 723 is connected to the first thermal conductive portion 721, and the other end is connected to the second thermal conductive portion 722. The other configuration is similar to the configuration described in the preceding embodiment.

[0103] <Summary of the second embodiment> According to this embodiment, by providing the communication holes 363 in the top wall 361 of the shield cover 36, the TIM 72 located above and below the top wall 361 are configured to be integrally connected. As a result, a portion of the heat generated by the electronic component 321 is transferred from the second thermally conductive portion 722 to the first thermally conductive portion 721 via the communication portions 723. This reduces loss due to thermal resistance at the interface between the shield cover 36 and the TIM 72, thereby improving heat dissipation. Furthermore, since the communication portions 723 arranged in the communication holes 363 function as anchors against displacement in the Z direction, it is possible to prevent the TIM 72 from shifting in position due to, for example, vibration.

[0104] Furthermore, since the diameter of the communication hole 363 is set to be equal to or less than half the wavelength of the frequency of the noise to be blocked, the effects described in the preceding embodiment can be achieved. For example, it is possible to prevent noise generated by the electronic components 321 and 322 from affecting the circuit board 40, particularly the electronic component 421 (SoC) and the electronic component 422 (memory), through the through hole 23. It is possible to prevent noise generated by the electronic components 421 and 422 from affecting the circuit board 40, particularly the electronic components 321 and 322, through the through hole 23. The above configuration is not limited to the circuit board 30 side. A similar configuration may be applied to the circuit board 40 side. For example, a communication hole may be provided in the top wall 461 of the shield cover 46, and the TIM 72 interposed between the electronic component 421 and the cooling plate 21 may have a first heat-conducting portion 721, a second heat-conducting portion 722, and a communication portion 723.

[0105] (Third embodiment) This embodiment is a modification of the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the communication hole 363 is provided in the top wall 361. Alternatively, an opening may be provided in the side wall 362.

[0106] Fig. 21 shows the positional relationship between the surface wiring and the lands that form the electromagnetic shield in an electronic device 10 according to the third embodiment. Fig. 22 is a cross-sectional view taken along line XXII-XXII shown in Fig. 21. In this embodiment, the solder resist on the circuit board 30 is also omitted.

[0107] As shown in FIG. 21 , land 315 to which shield cover 36 is connected has a generally C-shape in plan view. Land 315 has gap 3151. The width of gap 3151 is equal to or less than half the wavelength of the frequency of the noise to be blocked, and more preferably equal to or less than a quarter of the wavelength. Printed circuit board 31 has surface wiring 319 on the surface facing cooling plate 21. Surface wiring 319 is electrically connected to a first electronic component, for example electronic component 321. Surface wiring 319 is drawn out of land 315 through gap 3151.

[0108] The shield cover 36 has an opening 364 in a side wall 362. The opening 364 is provided at the lower end of the side wall 362 and penetrates the side wall 362. The opening 364 is provided at a position overlapping with the gap 3151 between the lands 315 in a plan view. The opening 364 is provided at a position overlapping with the surface wiring 319 in a plan view. The provision of the opening 364 ensures insulation of the surface wiring 319 from the shield cover 36. The size of the opening 364 is equal to or less than ½ wavelength of the frequency of the noise to be blocked, and more preferably equal to or less than ¼ wavelength. The other configurations are the same as those described in the preceding embodiment.

[0109] <Summary of the third embodiment> According to this embodiment, openings 364 are provided in side walls 362 of shield cover 36, and surface wiring 319 connected to electronic components 321 is led out of electromagnetic shield body 80 through the portions of printed circuit board 31 directly below openings 364. This improves the degree of freedom in wiring.

[0110] Furthermore, because the size of the opening 364 is set to be equal to or less than half the wavelength of the frequency of the noise to be blocked, the effects described in the preceding embodiments can be achieved. For example, it is possible to prevent noise generated by the electronic components 321 and 322 from affecting the circuit board 40, particularly the electronic components 421 (SoC) and 422 (memory), through the through hole 23. It is also possible to prevent noise generated by the electronic components 421 and 422 from affecting the circuit board 30, particularly the electronic components 321 and 322, through the through hole 23. In other words, it is possible to improve the degree of freedom in wiring while suppressing the effects of noise between the circuit boards 30 and 40.

[0111] If electrical insulation can be ensured by the solder resist (not shown) covering surface wiring 319, opening 364 may not be provided in sidewall 362, and gap 3151 may be provided in land 315.

[0112] (Fourth embodiment) This embodiment is a modification of the preceding embodiment, and the description of the preceding embodiment can be used. In the preceding embodiment, the shield cover 36 mounted on the printed circuit board 31 was used as the electromagnetic shield 80. Instead of this, a cylindrical shield wall may be used.

[0113] FIG. 23 is a plan view showing the periphery of an electronic component 321 in an electronic device 10 according to the fourth embodiment. FIG. 23 corresponds to FIG. 20. As shown in FIG. 23, a shield wall 37 is mounted on the surface of a printed circuit board 31 facing the cooling plate 21, instead of the shield cover 36. The shield wall 37 surrounds electronic components 32, such as the electronic component 321, arranged in the central region in a plan view. The shield wall 37 surrounds electronic components 32 that generate noise and / or are affected by noise. The shield wall 37 has, for example, a cylindrical shape. The lower end of the shield wall 37 is connected to the land 315, for example, by soldering. The upper end of the shield wall 37 is electrically connected to the cooling plate 21. The shield wall 37 and the cooling plate 21 may be electrically connected by the gasket 71 described above. The other configurations are the same as those described in the preceding embodiments.

[0114] <Summary of the Fourth Embodiment> According to this embodiment, the electromagnetic shield 80 includes the cooling plate 21, the shield wall 37, the land 315, the via conductor 316, and the ground layer 317. The through hole 23 is provided outside the shield wall 37 in a plan view. Therefore, it is possible to achieve the same effects as the configurations shown in the preceding embodiments.

[0115] Although not shown, the shield wall 37 may be divided into multiple sections in the circumferential direction, and gaps 3151 may be provided in the lands 315 to match the gaps in the shield wall 37. The gaps between adjacent shield walls may be set to ½ wavelength or less, more preferably ¼ wavelength or less, of the frequency of the noise to be blocked. This provides the same effect as the configuration shown in the third embodiment. That is, the surface wiring 319 connected to the electronic component 321 can be drawn out of the electromagnetic shield 80 through the portion directly below the gap in the shield wall 37. This allows for improved wiring flexibility while suppressing the effects of noise between the circuit boards 30 and 40.

[0116] (Other embodiments) The disclosure in this specification and drawings, etc. is not limited to the exemplified embodiments. The disclosure encompasses the exemplified embodiments and modifications thereto by those skilled in the art. For example, the disclosure is not limited to the combinations of parts and / or elements shown in the embodiments. The disclosure can be implemented in various combinations. The disclosure can have additional parts that can be added to the embodiments. The disclosure encompasses the omission of parts and / or elements from the embodiments. The disclosure encompasses the substitution or combination of parts and / or elements between one embodiment and another embodiment. The disclosed technical scope is not limited to the description of the embodiments. Some disclosed technical scopes are defined by the claims, and should be interpreted as including all modifications within the meaning and scope equivalent to the claims.

[0117] The disclosure in the specification, drawings, etc. is not limited by the claims. The disclosure in the specification, drawings, etc. encompasses the technical ideas described in the claims, and extends to more diverse and broader technical ideas than the technical ideas described in the claims. Therefore, various technical ideas can be extracted from the disclosure in the specification, drawings, etc. without being bound by the claims.

[0118] When an element or layer is referred to as being "on," "coupled," "connected," or "bonded," it may be directly on, coupled, connected, or bonded to another element or layer, and intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly coupled," "directly connected," or "directly bonded" to another element or layer, no intervening elements or layers are present. Other terms used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used in this specification, the term "and / or" includes any and all combinations of one or more of the associated listed items. That is, reference to A and / or B means at least one of A and B.

[0119] Spatially relative terms such as "inside," "outside," "back," "below," "low," "top," "top," and the like are used herein to facilitate the description of one element or feature's relationship to other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device during use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures were turned over, elements described as "below" or "directly below" other elements or features would then be oriented "above" the other elements or features. Thus, the term "bottom" can encompass both an orientation of top and bottom. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used in this specification would be interpreted accordingly.

[0120] Although an SoC is shown as an example of the electronic components 321, 421 having a processor, this is not limiting. As described above, a microcomputer may be used, or an MPU, GPU, DFP, etc. may also be used. MPU is an abbreviation for Micro-Processing Unit. GPU is an abbreviation for Graphics Processing Unit. DFP is an abbreviation for Data Flow Processor. The electronic components 32, 42 arranged in the central region may include an ASIC, FPGA, etc. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array. [Explanation of symbols]

[0121] 10...electronic device, 20...cooler, 21...cooling plate, 21a...one side, 21b...rear side, 211...main body portion, 212, 213...side plate portion, 22, 221, 2211, 2212, 2213, 222, 2221, 2222, 2223, 2224...wall portion, 23...through hole, 24...flow path, 24a...bottom, 241...partition wall, 242...inlet portion, 243...outlet portion, 25, 251, 252, 253, 254, 255...fixing portion, 26...inlet pipe, 27...outlet pipe, 2 8...flow path cover, 281...fin, 29...refrigerant, 30...circuit board, 31...printed circuit board, 31...insulating base material, 312, 3121, 3122, 313, 315...land, 314...through hole land, 3151...gap, 316, 318...via conductor, 317...ground layer, 319...surface wiring, 32, 321, 322, 323, 324, 325...electronic components, 33, 34...connector, 35, 351, 352, 353...through hole, 36...shield 3. A solder cover, 361...top wall, 362...side wall, 363...communicating hole, 364...opening, 37...shield wall, 40, 401, 402...circuit board, 41...printed circuit board, 41...insulating base material, 412, 4121, 4122, 4123, 4124, 413, 415...land, 414...through hole land, 416, 418...via conductor, 417...ground layer, 42, 421, 422, 423, 424...electronic components, 43, 44...connector, 45 , 451, 452...Through-hole, 46...Shield cover, 461...Top wall, 462...Side wall, 50, 501, 502, 503...Back plate, 51...Frame portion, 52...Leg portion, 60...Housing, 61, 62...Cover, 610, 620...Through-hole, 63, 64...Side plate, 630, 631, 640...Through-hole, 70...Screw, 71...Gasket, 72...TIM, 721...First heat-conducting portion, 722...Second heat-conducting portion, 723...Communicating portion, 80, 81...Electromagnetic shield body

Claims

1. a cooling plate (21) having one surface (21a), a back surface (21b) opposite to the one surface in a predetermined direction, and through holes (23) opening to the one surface and the back surface; a first circuit board (30) disposed on the one surface and having at least one first electronic component (321, 322) on a surface opposite to the one surface; a second circuit board (40) disposed on the rear surface and having at least one second electronic component (421, 422) on a surface facing the rear surface; a connection portion (33, 43) that electrically connects the first circuit board and the second circuit board through the through hole; A shield base (317) arranged on the one side; a shield cover (36) mounted on the first circuit board and arranged to cover the first electronic component; Equipped with the first circuit board has a ground conductor (315, 316) that provides a reference potential, is arranged to surround the first electronic component when viewed in a plan view in the predetermined direction, and is electrically connected to the shield base; the shield base is provided to enclose the ground conductor in the plan view, the shield cover is electrically connected to the shield base via the ground conductor; The first electronic component is disposed inside an electromagnetic shield (80) including the shield base, the ground conductor, and the shield cover.

2. 2. The electronic device according to claim 1, further comprising a heat conducting member (72) for transferring heat generated by the first electronic component.

3. the shield cover has a top wall (361) disposed between an upper surface of the first electronic component and the one surface of the cooling plate, The electronic device according to claim 2 , wherein the heat conducting member is interposed between the top wall and the cooling plate.

4. The electronic device according to claim 3 , wherein the heat conducting member is interposed between the first electronic component and the top wall.

5. The shield cover has a communication hole (363) in the top wall, the communication hole having a diameter equal to or smaller than half the wavelength of the frequency of the noise to be blocked, 5. The electronic device of claim 4, wherein the heat conduction member has a first heat conduction portion (721) interposed between the top wall and the cooling plate, a second heat conduction portion (722) interposed between the first electronic component and the top wall, and a communication portion (723) arranged in the communication hole and connected to each of the first heat conduction portion and the second heat conduction portion.

6. the shield cover has a top wall (361) disposed between an upper surface of the first electronic component and the one surface of the cooling plate, The electronic device according to claim 2 , wherein the heat conducting member is interposed between the first electronic component and the top wall.

7. the shield cover has a top wall (361) disposed between an upper surface of the first electronic component and the one surface of the cooling plate, and a side wall (362) connected to the top wall and having a lower end electrically connected to the first circuit board, An opening (364) having a size equal to or smaller than half the wavelength of the frequency of the noise to be blocked is provided at the lower end of the side wall, 2. The electronic device according to claim 1, wherein the first circuit board has a surface wiring (319) electrically connected to the first electronic component and extending outside the electromagnetic shield through a portion directly below the opening.

8. a back plate (50, 501) that presses the first circuit board against the cooling plate; 8. The electronic device according to claim 1, wherein the back plate is disposed across the shield cover in the plan view and is fixed to the cooling plate at a position that does not overlap with the shield cover.

9. 8. The electronic device according to claim 1, wherein the shield base is a ground layer disposed at a position on the first circuit board farther from the one surface than a surface on which the first electronic component is mounted.

10. The electronic device according to claim 9 , wherein the ground conductor includes a land provided in an annular shape so as to surround the first electronic component, and a plurality of via conductors that electrically connect the land and the ground layer.

11. 8. The electronic device according to claim 1, wherein the first circuit board includes an SoC as the first electronic component.

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