Electronic device

Abstract

An electronic device according to the present technology comprises an enclosure, a first board, a second board, an electronic component, and an air-blowing mechanism. The enclosure has a waterproof structure. The first board is accommodated in the enclosure and has a first surface and a second surface opposite the first surface. The second board is accommodated in the enclosure and has a third surface facing the second surface and a fourth surface opposite the third surface. The electronic component is mounted on at least one of the following: the first surface, the second surface, the third surface, and the fourth surface. Let an inter-board flow path be defined as the space between the second surface and the third surface; in this case the air-blowing mechanism generates a flow of air in the inter-board flow path.

Description

electronic equipment

[0001] The present technology relates to an electronic device equipped with a cooling mechanism for electronic components.

[0002] Heat generation from electronic components can be a problem in electronic devices such as smartphones. In recent years, there has been an increase in processes that require high loads over a certain period of time and generate a large amount of heat, such as 4K video recording. However, many electronic devices such as smartphones require waterproofing, making it impossible to adopt a configuration that dissipates heat by venting it to the outside of the housing. Therefore, a typical heat dissipation structure for smartphones and other devices is configured to transfer heat generated in internal components to the housing via a heat dissipation member such as a vapor chamber, and then dissipate the heat from the housing.

[0003] In recent years, two-story boards, in which two circuit boards are stacked with a predetermined gap between them, have become increasingly popular. Because it is difficult to place heat dissipation members on both sides of a two-story board, heat from built-in components must be dissipated from a heat dissipation member placed on one side of the board unit. However, heat must be transferred from one circuit board to the other, which is separated from the other, creating a problem of heat dissipation from the built-in components.

[0004] In response to this, Patent Document 1 discloses a radio relay device for broadcasting that uses a fan to blow air between two circuit boards. The air blown between the two circuit boards absorbs heat from the heat-generating components, then flows along the side of the housing, where the heat is dissipated.

[0005] JP 2012-79978 A

[0006] However, in the broadcasting radio relay device described in Patent Document 1, the centrifugal fan and heat sink are located outside the housing, and the centrifugal fan blows air to the heat sink to cool the heat-generating components housed in the housing. For this reason, it is difficult to adopt a similar structure in a mobile device such as a smartphone.

[0007] In view of the above circumstances, an object of the present technology is to provide an electronic device that is suitable for a waterproof structure and has excellent heat dissipation properties for electronic components mounted on a two-story board.

[0008] To achieve the above object, an electronic device according to one embodiment of the present technology includes a housing, a first substrate, a second substrate, an electronic component, and a blower mechanism. The housing has a waterproof structure. The first substrate is housed in the housing and has a first surface and a second surface opposite to the first surface. The second substrate is housed in the housing and has a third surface facing the second surface and a fourth surface opposite to the third surface. The electronic component is mounted on at least one of the first surface, the second surface, the third surface, and the fourth surface. When the space between the second surface and the third surface is defined as an inter-board flow path, the blower mechanism generates an air flow in the inter-board flow path.

[0009] When at least one of the spaces between the first surface and the housing and the spaces between the fourth surface and the housing is an extra-substrate flow path, the blowing mechanism may form a flow of air that passes from the blowing mechanism through the inter-substrate flow path and the extra-substrate flow path and returns to the blowing mechanism.

[0010] The electronic device may further include a connection member disposed between the first substrate and the second substrate, connecting the first substrate and the second substrate, and not blocking the inter-substrate flow path.

[0011] The connection member may electrically connect the first substrate and the second substrate, surround a space together with the first substrate and the second substrate, and have an opening that connects the inside of the space to the outside.

[0012] The opening may include a first opening and a second opening, the air blowing mechanism may form a flow of air that flows into the space through the first opening and flows out of the space through the second opening, and the inter-substrate flow path may be between the first opening and the second opening.

[0013] The first substrate may have a through hole provided between the first surface and the second surface, the blowing mechanism may form a flow of air that flows into the space through the through hole and flows out of the space through the opening, and the inter-substrate flow path may be between the through hole and the opening.

[0014] The electronic device may further include a third substrate housed in the housing and having a fifth surface facing the fourth surface and a sixth surface opposite the fifth surface, and the space between the fourth surface and the fifth surface may further serve as the inter-substrate flow path.

[0015] If the space between the first surface and the housing and the space between the sixth surface and the housing are defined as extra-substrate flow paths, the blowing mechanism may form a flow of air that passes from the blowing mechanism through the inter-substrate flow path and the extra-substrate flow path and returns to the blowing mechanism.

[0016] The electronic device may further include a heat diffusion member disposed in the outside-substrate flow path.

[0017] The inter-substrate flow path may be a gap between a plurality of electronic components mounted on at least one of the second surface and the third surface.

[0018] The electronic device may further include a microphone housed in the housing, and the first board and the second board may be disposed between the air blowing mechanism and the microphone.

[0019] The electronic device may further include a battery housed in the housing, the microphone may include a first microphone arranged at one longitudinal end of the housing and a second microphone arranged at the other longitudinal end of the housing, the first board and the second board may be arranged between the air blowing mechanism and the first microphone, and the battery may be arranged between the air blowing mechanism and the second microphone.

[0020] 1 is a plan view of an electronic device according to an embodiment of the present technology. FIG. 1 is a plan view of the electronic device. FIG. 2 is a schematic view of a waterproof structure of the electronic device. FIG. 3 is a schematic view of a waterproof region of the electronic device. FIG. 4 is a perspective view and a plan view of an external connection terminal included in the electronic device. FIG. 5 is a cross-sectional view of a first microphone included in the electronic device. FIG. 6 is a schematic view of a waterproof structure relating to an opening of the electronic device. FIG. 7 is a schematic view of a waterproof region of the electronic device. FIG. 8 is a schematic view of a waterproof moisture-permeable membrane disposed in an opening of the electronic device. FIG. 10 is a plan view of an electronic device according to an embodiment of the present technology. FIG. 11 is a cross-sectional view of the electronic device. FIG. 12 is a perspective view of a board unit included in the electronic device. FIG. 13 is an exploded perspective view of the board unit. FIG. 14 is a cross-sectional view of the board unit. FIG. 15 is a schematic view showing airflow in the electronic device. FIG. 16 is a schematic view showing airflow in an electronic device according to a comparative example. FIG. 17 is a perspective view of a connecting member having another configuration of a board unit included in an electronic device according to an embodiment of the present technology. FIG. 18 is a perspective view of a connecting member having another configuration of the board unit. FIG. 19 is a perspective view of a board unit including a connecting member having another configuration included in the electronic device according to an embodiment of the present technology. 1 is a schematic diagram showing inter-board flow paths formed by electronic components in a board unit included in the electronic device. FIG. 1 is a schematic diagram showing inter-board flow paths formed by electronic components in a board unit included in the electronic device. FIG. 2 is an exploded perspective view of a board unit on which a blower mechanism is arranged, included in the electronic device. FIG. 3 is a perspective view of a first board included in the board unit. FIG. 4 is a schematic diagram showing air blowing in the electronic device. FIG. 5 is a schematic diagram showing air blowing in the electronic device. FIG. 6 is a perspective view of a first board having another configuration included in the board unit. FIG. 7 is a perspective view of a first board having another configuration included in the board unit. FIG. 8 is a cross-sectional view of an electronic device including a heat conductive member according to an embodiment of the present technology. FIG. 9 is a cross-sectional view of an electronic device including a board unit that is a three-story board according to an embodiment of the present technology. FIG. 10 is a cross-sectional view of the board unit. FIG. 11 is a schematic diagram showing air blowing in the electronic device. FIG. 12 is a plan view of an electronic device having another configuration according to an embodiment of the present technology.1A and 1B are plan views of an electronic device including a heat diffusion member according to an embodiment of the present technology, and an electronic device including another circuit board according to an embodiment of the present technology.

[0021] [Configuration of Electronic Device] An electronic device 100 according to an embodiment of the present technology will be described. Fig. 1 is a plan view of the electronic device 100 as viewed from the front side, and Fig. 2 is a plan view of the electronic device 100 as viewed from the rear side. As shown in these figures, the electronic device 100 is a smartphone, and includes a housing 101, a headset connection terminal 141, an external connection terminal 142, a first microphone 143, a second microphone 144, a first speaker 145, a second speaker 146, and a camera 147. Operation buttons and the like (not shown) are provided on the side of the electronic device 100.

[0022] The housing 101 forms a waterproof structure together with each component of the electronic device 100 and houses each component. The housing 101 is formed by joining a frame, a display, and a rear panel. In addition, the housing 101 may have a waterproof structure and may be capable of housing each component of the electronic device 100.

[0023] Fig. 3 is a schematic diagram showing the waterproof structure of housing 101, and Fig. 4 is a schematic diagram of a waterproof region within housing 101 where waterproofing is ensured. In Fig. 4, the waterproof region is indicated by hatching. As shown in Fig. 3, headset connection terminal 141 is mounted on substrate 151, and a portion of it is exposed to the outside of housing 101. The space between headset connection terminal 141 and housing 101 is sealed and waterproofed by waterproof member 152. Waterproof member 152 is made of an elastic material such as rubber, and is, for example, an O-ring.

[0024] The external connection terminal 142 is a terminal for external connection such as a USB (Universal Serial Bus) connection terminal, and is mounted on a substrate 153 as shown in Fig. 3, with a portion exposed to the outside of the housing 101. Fig. 5 shows the external connection terminal 142, with Fig. 5(a) being a perspective view and Fig. 5(b) being a side view. As shown in these figures, the external connection terminal 142 has a terminal body 154 and an insert mold 155, and the insert mold 155 seals the gap between the terminal body 154 and the housing 101, thereby making it waterproof.

[0025] The first microphone 143 is mounted on a substrate 151 as shown in Fig. 3. Fig. 6 is a cross-sectional view of the first microphone 143. As shown in Fig. 6, the first microphone 143 is a MEMS (Micro Electro Mechanical Systems) microphone and includes a diaphragm 156, a back plate 157, a support portion 158, a seal 159, an integrated circuit 160, and a case 161. The diaphragm 156, the back plate 157, the support portion 158, and the seal 159 are configured by a MEMS chip. The first microphone 143 detects sound waves that enter a cavity 163 through a sound hole 162 provided in the substrate 151 by the vibration of the diaphragm 156.

[0026] The sound hole 162 is connected to an opening provided in the housing 101. The second microphone 144 has a configuration similar to that of the first microphone 143, and collects sound through a sound hole connected to an opening provided in the housing 101. The first speaker 145 and the second speaker 146 have a general structure, and emit sound through openings provided in the housing 101. Fig. 7 is a schematic diagram showing the waterproof structure related to the openings of the housing 101, and Fig. 8 is a schematic diagram of a waterproof area within the housing 101 where waterproofing is ensured. In Fig. 8, the waterproof area is indicated by hatching.

[0027] As shown in Fig. 7, the housing 101 has an opening 164 that connects the inside and outside of the housing 101. The first speaker 145 and the second speaker 146 emit sound through the opening 164, and the first microphone 143 and the second microphone 144 collect sound through the opening 164. The opening 164 for emitting sound and the opening 164 for collecting sound may be the same or different. A waterproof and breathable membrane 165 is disposed in the opening 164, separating the inside and outside of the housing 101.

[0028] 9 is a schematic diagram of the waterproof / moisture-permeable membrane 165. As shown in the figure, the waterproof / moisture-permeable membrane 165 is a porous membrane having pores 166. The pores 166 have a pore diameter of 0.1 to 5 μm, and water droplets D having a size of approximately 100 to 3000 μm cannot pass through, but water vapor V and air having a size of approximately 0.0004 μm can pass through. Therefore, by disposing the waterproof / moisture-permeable membrane 165 in the opening 164, the waterproofness of the waterproof region shown in FIG. 8 can be ensured.

[0029] The waterproof structure of the electronic device 100 described above is an example, and the configuration of the electronic device 100 according to this embodiment is not limited to the above.

[0030] Next, the internal structure of electronic device 100 will be described. Fig. 10 is a plan view of the internal structure of electronic device 100, and Fig. 11 is a cross-sectional view of electronic device 100. Fig. 10 is a view of electronic device 100 as seen from the rear side (camera 107 side). As shown in Fig. 11, the rear side of housing 101 is housing rear side 101a, the front side is housing front side 101b, and the side side is housing side side 101c.

[0031] As shown in Fig. 11 , the board unit 102 is housed in a housing 101, and various electronic components of the electronic device 100 are mounted on it. Fig. 12 is a perspective view of the board unit 102, Fig. 13 is an exploded perspective view of the board unit 102, and Fig. 14 is a cross-sectional view of the board unit 102. As shown in these figures, the board unit 102 includes a first board 121, a second board 122, a connecting member 123, and electronic components 124. The board unit 102 has a structure in which the first board 121 and the second board 122 are stacked with a gap between them, and is also called a two-story board.

[0032] The first substrate 121 is a circuit substrate on the housing rear surface 101a side of the substrate unit 102. The type of the first substrate 121 is not particularly limited, and it is, for example, a PWB (printed wiring board). As shown in Fig. 14, the main surface of the first substrate 121 facing the housing rear surface 101a is referred to as a first surface 121a, and the main surface opposite the first surface 121a and facing the second substrate 122 is referred to as a second surface 121b. The shape of the first substrate 121 is not particularly limited, and it does not have to be rectangular.

[0033] The second substrate 122 is a circuit substrate on the housing surface 101b side of the substrate unit 102. The type of the second substrate 122 is not particularly limited, and may be, for example, a PWB. As shown in FIG. 14 , the main surface of the second substrate 122 facing the first substrate 121 is referred to as a third surface 122a, and the main surface opposite the third surface 122a and facing the housing surface 101b is referred to as a fourth surface 122b. The third surface 122a is the surface facing the second surface 121b of the first substrate 121. The shape of the second substrate 122 is not particularly limited, and may be a shape different from that of the first substrate 121 as long as at least a portion of the second substrate 122 faces the first substrate 121.

[0034] The connection member 123 is disposed between the first substrate 121 and the second substrate 122 and connects the first substrate 121 and the second substrate 122. The connection member 123 preferably not only physically connects the first substrate 121 and the second substrate 122 but also electrically connects them. Specifically, the connection member 123 includes terminals and wiring that can be connected to terminals provided on the second surface 121b and the third surface 122a, respectively, and can transmit and receive signals between the first substrate 121 and the second substrate 122.

[0035] As shown in Fig. 13 , the connecting member 123 has a ring-shaped configuration surrounding all four sides, and can be configured to surround a space together with the first substrate 121 and the second substrate 122. Hereinafter, as shown in Fig. 14 , the space surrounded by the connecting member 123, the first substrate 121, and the second substrate 122 will be referred to as the "mounting space R." As shown in Fig. 13 , the connecting member 123 is provided with a first opening 123a and a second opening 123b. These openings penetrate the connecting member 123 and communicate the inside and outside of the mounting space R. The first opening 123a is provided on one side of the connecting member 123, and two second openings 123b are provided on the side of the connecting member 123 facing the first opening 123a.

[0036] The electronic components 124 are electronic components that perform various functions of the electronic device 100, and are, for example, a system on a chip (SoC), a memory, a communication module, a sensor, etc. The electronic components 124 are mounted on at least one of the first surface 121a, the second surface 121b, the third surface 122a, and the fourth surface 122b. The type, number, and arrangement of the electronic components 124 are not particularly limited. The electronic components 124 may also be covered with a shield that blocks noise.

[0037] The air blowing mechanism 103 is housed inside the housing 101 and blows air. The air blowing mechanism 103 is, for example, a fan, but may be another type of air blowing mechanism. As shown in Figures 10 and 11, the air blowing mechanism 103 is disposed adjacent to the board unit 102 and blows air to the board unit 102. Figure 15 is a schematic diagram showing air blown by the air blowing mechanism 103.

[0038] As indicated by arrows A1 and A2 in the figure, air sent out from the blower mechanism 103 flows into the mounting space R through the first opening 123a and flows out of the mounting space R through the second opening 123b. Therefore, a flow path is formed between the second surface 121b and the third surface 122a, running from the first opening 123a through the mounting space R to the second opening 123b. Hereinafter, this flow path will be referred to as the "inter-board flow path."

[0039] As shown by arrow A1, a portion of the air that has passed through the inter-substrate flow path passes between the first surface 121a and the housing 101 and returns to the blower mechanism 103. Furthermore, as shown by arrow A2, another portion of the air that has passed through the inter-substrate flow path passes between the fourth surface 122b and the housing 101 and returns to the blower mechanism 103. Therefore, between the first surface 121a and the housing 101 and between the fourth surface 122b and the housing 101, flow paths are formed that run from the inter-substrate flow path through the outside of the substrate unit 102 to the blower mechanism 103. Hereinafter, these flow paths will be referred to as "extra-substrate flow paths."

[0040] The air that returns from the extra-substrate flow path to the blower mechanism 103 is blown out again by the blower mechanism 103 and flows through the inter-substrate flow path and the extra-substrate flow path. Therefore, the air blown out by the blower mechanism 103 circulates through the inter-substrate flow path and the extra-substrate flow path. Note that multiple blower mechanisms 103 may be provided.

[0041] The battery 104 is housed in the housing 101 and supplies driving power to the electronic device 100. As shown in Fig. 10, the battery 104 is arranged together with the board unit 102 so as to sandwich the blower mechanism 103 therebetween.

[0042] The first microphone 143 is a noise-canceling microphone, and the second microphone 144 is a sound-collecting microphone. As shown in Fig. 10 , the first microphone 143 is disposed at one longitudinal end of the housing 101, and the second microphone 144 is disposed at the other longitudinal end of the housing 101. As described above, the air blowing mechanism 103 is sandwiched between the board unit 102 and the battery 104, and as shown in Fig. 10 , the board unit 102 is disposed between the air blowing mechanism 103 and the first microphone 143, and the battery 104 is disposed between the air blowing mechanism 103 and the second microphone 144. This separates the air blowing mechanism 103 from the first microphone 143 and the second microphone 144, preventing the operating sound of the air blowing mechanism 103 from being picked up by these microphones.

[0043] [Effects of Electronic Device] The effects of electronic device 100 will be described in comparison with a comparative example. Fig. 16 is a schematic diagram of electronic device 300 according to the comparative example. As shown in the figure, electronic device 300 includes a housing 301, a board unit 302, and a blower mechanism 303. Board unit 302 includes a first board 321, a second board 322, a connecting member 323, and electronic components 324. First board 321 and second board 322 are connected by connecting member 323, and electronic components 324 are mounted on both the front and back sides.

[0044] The air sent out from the air blower mechanism 303 flows and circulates between the board unit 302 and the housing 301 as shown by the arrows in the figure. In this configuration, the electronic components 324 mounted on the first surface 321a and the fourth surface 322b are cooled by the airflow, but the electronic components 324 mounted on the second surface 321b and the third surface 322a are not cooled by the airflow. As a result, there is a risk that the electronic components 324 may become hot due to high-load processing.

[0045] It is also possible to configure the housing 301 to dissipate heat from the rear side (the lower side in the figure) of the housing 301 without providing the air blowing mechanism 303. In this case, it is necessary to place a thermal conductive member such as a TGF (thermal gap filler) between the electronic components 324 mounted on the second surface 321b and the third surface 322a. Even with this configuration, there is a risk that the amount of heat dissipation will be insufficient during high-load processing, resulting in high temperatures.

[0046] In contrast, in electronic device 100, as described above, the air sent out by blower mechanism 103 passes through the inter-board flow paths, then passes through the extra-board flow paths and returns to blower mechanism 103, circulating through the inter-board flow paths and the extra-board flow paths (see FIG. 15 ). The air flowing through the inter-board flow paths cools electronic components 124 mounted on second surface 121 b and third surface 122 a, and the air flowing through the extra-board flow paths cools electronic components 124 mounted on first surface 121 a and fourth surface 122 b. This allows the boards mounted on each surface of board unit 102 to be evenly cooled, making it possible to achieve continuous high-load operation.

[0047] Furthermore, if the housing 101 is made waterproof, it becomes difficult to allow a large amount of air to flow in and out of the inside and outside of the housing 101 to cool the electronic components 124. However, in the electronic device 100, there is no need for air to flow in and out of the housing 101 to cool the electronic components 124, so it is possible to achieve both the waterproof performance of the housing 101 and the cooling performance of the electronic components 124.

[0048] [Other Configurations of the Board Unit] The shape, number, and arrangement of the first opening 123a and the second opening 123b of the connecting member 123 are not particularly limited. Figures 17 and 18 are perspective views of connecting members 123 having other configurations. As shown in Figure 17, the second opening 123b may be slits provided above and below the connecting member 123. As shown in Figure 18, the first opening 123a may be a single circular opening, and the second opening 123b may be two circular openings. Alternatively, the first opening 123a and the second opening 123b may have a shape that allows a sufficient amount of air to pass through. It is preferable that the first opening 123a and the second opening 123b be arranged in accordance with the arrangement of the electronic components 124 so that the inter-board flow path is not obstructed by the electronic components 124.

[0049] The connecting member 123 is not limited to having a ring shape surrounding the four sides as described above. Figures 19 and 20 are perspective views of the board unit 102 including connecting members 123 having other configurations. As shown in Figure 19, the connecting members 123 may be a pair of wall-like members that are arranged on two sides of the board unit 102, connect the first board 121 and the second board 122, and face each other. In this case, a first opening 123a and a second opening 123b are formed between the two connecting members 123.

[0050] 20, the connecting member 123 may be a columnar member that connects the first substrate 121 and the second substrate 122. In this case, a first opening 123a and a second opening 123b are also formed between the two connecting members 123. In addition to this, the connecting member 123 may be any member that connects the first substrate 121 and the second substrate 122 and does not block the flow path between the substrates.

[0051] The substrate unit 102 may further include a wiring substrate connected to at least one of the first substrate 121 and the second substrate 122. Fig. 21 is a perspective view of the substrate unit 102 including the wiring substrate 125. As shown in the figure, the wiring substrate 125 is preferably positioned so as not to block the first opening 123a and the second opening 123b. The wiring substrate 125 is, for example, an FPC (Flexible Printed Circuits).

[0052] Furthermore, the inter-substrate flow path provided between the first substrate 121 and the second substrate 122 may be formed by the electronic components 124. Figures 22 and 23 are schematic diagrams showing the inter-substrate flow path formed by the electronic components 124. When multiple electronic components 124 are mounted on the second surface 121b as shown in these figures, inter-substrate flow paths are formed in the gaps between the multiple electronic components 124, as indicated by the arrows in the figures. In particular, when the height of the electronic components 124 is close to the distance between the first substrate 121 and the second substrate 122, air flows almost entirely through the gaps between the electronic components 124.

[0053] 22 and 23 show electronic components 124 mounted on the second surface 121b, inter-board flow paths may be formed in the gaps between multiple electronic components 124 mounted on the third surface 122a. Also, inter-board flow paths may be formed in the gaps between multiple electronic components 124 mounted on both the second surface 121b and the third surface 122a.

[0054] Furthermore, the blower mechanism 103 can also be disposed within the substrate unit 102. Fig. 24 is an exploded perspective view of the substrate unit 102 in which the blower mechanism 103 is disposed. Fig. 25 is a perspective view of a first substrate 121 that constitutes the substrate unit 102. As shown in Fig. 25, the first substrate 121 has a through-hole 121c between the first surface 121a and the second surface 121b. As shown in Fig. 24, the blower mechanism 103 is disposed on the second surface 121b and adjacent to the through-hole 121c. The connecting member 123 has an opening 123c.

[0055] 26 and 27 are schematic diagrams showing air blown by air blowing mechanism 103 in this configuration. As indicated by solid arrows in these figures, air blown out from air blowing mechanism 103 flows through mounting space R and exits mounting space R through opening 123c. Therefore, an inter-board flow path is formed between second surface 121b and third surface 122a, running from air blowing mechanism 103 through mounting space R to opening 123c.

[0056] As shown by the solid arrows, a portion of the air that has passed through the inter-substrate flow paths passes between first surface 121a and housing 101, flows into through-hole 121c, and returns to blower mechanism 103. Furthermore, a portion of the air that has passed through the inter-substrate flow paths passes between fourth surface 122b and housing 101, as shown by the dashed arrows, and then flows in a direction where opening 123c is not provided, as shown by the dashed-dotted arrows, and returns to blower mechanism 103 via through-hole 121c. Therefore, between first surface 121a and housing 101 and between fourth surface 122b and housing 101, extra-substrate flow paths are formed that run from the inter-substrate flow paths to the outside of substrate unit 102 and reach blower mechanism 103. The air that has returned from the extra-substrate flow paths to blower mechanism 103 is again sent out by blower mechanism 103 and circulates through the inter-substrate flow paths and the extra-substrate flow paths.

[0057] The shape of the through-holes 121c is not particularly limited. Figures 28 and 29 are perspective views of the first substrate 121 provided with through-holes 121c of various shapes. The through-holes 121c do not have to be circular as shown in Figure 28, and may be a plurality of holes as shown in Figure 29. Any other through-holes 121c may be used as long as they allow a sufficient amount of air to pass through.

[0058] Note that the blower mechanism 103 may be provided on the first surface 121a instead of the second surface 121b. The blower mechanism 103 may also be provided on the third surface 122a or the fourth surface 122b of the second substrate 122. In this case, a through-hole is provided in the second substrate 122 between the third surface 122a and the fourth surface 122b, and the blower mechanism 103 is adjacent to this through-hole. In this configuration, an extra-substrate flow path is formed between the fourth surface 122b and the housing 101, which runs from the inter-substrate flow path through the outside of the substrate unit 102 to the blower mechanism 103. The blower mechanism 103 may be provided on both the first substrate 121 and the second substrate 122.

[0059] The substrate unit 102 may further include a thermally conductive member. FIG. 30 is a cross-sectional view of the substrate unit 102 including the thermally conductive member 108. As shown in the figure, the thermally conductive member 108 is disposed between the electronic components 124 mounted on the second surface 121a and the electronic components 124 mounted on the third surface 122a, and contacts these electronic components to conduct heat. The thermally conductive member 108 may be, for example, a thermal gap filler (TGF). It is preferable that the thermally conductive member 108 not obstruct the inter-substrate flow path between the first substrate 121 and the second substrate 122 as much as possible.

[0060] [Regarding the Number of Circuit Boards] The board unit 102 is not limited to the two-story board described above, but may be a three-story board. Fig. 31 is a cross-sectional view of an electronic device 100 including a board unit 102 that is a three-story board, and Fig. 32 is a cross-sectional view of this board unit 102. As shown in these figures, the board unit 102 includes a first board 131, a second board 132, a third board 133, a first connecting member 134, a second connecting member 135, and an electronic component 136. This board unit 102 has a structure in which the first board 131 and the second board 132 are stacked with a gap therebetween, and the second board 132 and the third board 133 are stacked with a gap therebetween, i.e., it is a three-story board.

[0061] The first substrate 131 is a circuit substrate on the housing rear surface 101a side of the substrate unit 102. The type of the first substrate 131 is not particularly limited, and it is, for example, a PWB (printed wiring board). As shown in Fig. 32 , of the main surfaces of the first substrate 131, the surface on the housing rear surface 101a side is referred to as a first surface 131a, and the surface opposite to the first surface 131a and on the second substrate 132 side is referred to as a second surface 131b. The shape of the first substrate 131 is not particularly limited, and it does not have to be rectangular.

[0062] The second substrate 132 is a circuit substrate between the first substrate 131 and the third substrate 132 of the substrate unit 102. The type of the second substrate 132 is not particularly limited, and may be, for example, a PWB. As shown in FIG. 32 , the main surface of the second substrate 132 facing the first substrate 131 is referred to as the third surface 132a, and the main surface opposite the third surface 132a and facing the third substrate 133 is referred to as the fourth surface 132b. The third surface 132a is the surface facing the second surface 131b. The shape of the second substrate 132 is not particularly limited, and may be a shape different from that of the first substrate 131 as long as at least a portion of the second substrate 132 faces the first substrate 131.

[0063] The third substrate 133 is a circuit substrate on the housing surface 101b side of the substrate unit 102. The type of the third substrate 133 is not particularly limited, and may be, for example, a PWB. As shown in FIG. 32 , the main surface of the third substrate 133 facing the second substrate 132 is designated as a fifth surface 133a, and the main surface opposite the fifth surface 133a and facing the housing surface 101b is designated as a sixth surface 133b. The fifth surface 133a faces the fourth surface 132b. The shape of the third substrate 133 is not particularly limited, and may be a shape different from the first substrate 131 and the second substrate 132 as long as at least a portion of the third substrate 133 faces the third substrate 132.

[0064] The first connection member 134 is disposed between the first substrate 131 and the second substrate 132 and connects the first substrate 131 and the second substrate 132. The first connection member 134 preferably not only physically connects the first substrate 131 and the second substrate 132 but also electrically connects them. Specifically, the first connection member 134 has terminals and wiring that can be connected to terminals provided on the second surface 131b and the third surface 132a, respectively, and can transmit and receive signals between the first substrate 131 and the second substrate 132.

[0065] The first connecting member 134 has a ring-shaped configuration surrounding all four sides and can be configured to surround the first mounting space R1 together with the first substrate 131 and the second substrate 132. As shown in FIG. 32 , the first connecting member 134 is provided with a first opening 134a and a second opening 134b. These openings penetrate the first connecting member 134 and connect the inside and outside of the first mounting space R1. The first opening 134a is provided on one side of the first connecting member 134, and the second opening 134b is provided on the side of the first connecting member 134 opposite the first opening 134a. The shapes, arrangements, and numbers of the first openings 134a and the second openings 134b are not particularly limited.

[0066] The second connection member 135 is disposed between the second substrate 132 and the third substrate 133, and connects the second substrate 132 and the third substrate 133. The second connection member 135 preferably not only physically connects the second substrate 132 and the third substrate 133, but also electrically connects them. Specifically, the second connection member 135 includes terminals and wiring that can be connected to the terminals provided on the fourth surface 132b and the fifth surface 133a, respectively, and can transmit and receive signals between the second substrate 132 and the third substrate 133.

[0067] The second connection member 135 has an annular shape surrounding all four sides and can be shaped to surround the second mounting space R2 together with the second substrate 132 and the third substrate 132. As shown in FIG. 32 , the second connection member 135 is provided with a first opening 135a and a second opening 135b. These openings penetrate the second connection member 135 and connect the inside and outside of the second mounting space R2. The first opening 135a is provided on one side of the third connection member 135, and the second opening 135b is provided on the side of the second connection member 135 opposite the first opening 135a. The shapes, arrangements, and numbers of the first openings 135a and the second openings 135b are not particularly limited.

[0068] The electronic components 136 are electronic components that perform various functions of the electronic device 100, and are mounted on at least one of the first surface 131 a, the second surface 131 b, the third surface 132 a, the fourth surface 132 b, the fifth surface 133 a, and the sixth surface 133 b. The type, number, and arrangement of the electronic components 136 are not particularly limited. The electronic components 136 may also be covered with a shield that blocks noise.

[0069] 33 is a schematic diagram showing airflow by the blower mechanism 103 to the substrate unit 102, which is a three-story substrate. As indicated by arrow A1 in the figure, air blown out from the blower mechanism 103 flows into the first mounting space R1 through the first opening 134a and flows out of the first mounting space R1 through the second opening 134b. Therefore, an inter-substrate flow path is formed between the second surface 131b and the third surface 132a, passing from the first opening 134a through the first mounting space R1 to the second opening 134b. Furthermore, as indicated by arrow A1, the air that has passed through the inter-substrate flow path passes between the first surface 131a and the housing 101 and returns to the blower mechanism 103. Therefore, an extra-substrate flow path is formed between the first surface 131a and the housing 101, passing from the inter-substrate flow path to the outside of the substrate unit 102 and to the blower mechanism 103.

[0070] 32 , air sent out from the blower mechanism 103 flows into the second mounting space R2 through the first opening 135a and flows out of the first mounting space R2 through the second opening 135b. Therefore, an inter-board flow path is formed between the fourth surface 132b and the fifth surface 133a, passing from the first opening 135a through the second mounting space R2 to the second opening 135b. Furthermore, as shown by the arrow A2, the air that has passed through the inter-board flow path passes between the sixth surface 133b and the housing 101 and returns to the blower mechanism 103. Therefore, an extra-board flow path is formed between the sixth surface 133b and the housing 101, passing from the inter-board flow path to the outside of the board unit 102 and to the blower mechanism 103.

[0071] The air that returns from the extra-board flow path to the blower mechanism 103 is blown out again by the blower mechanism 103 and flows through the inter-board flow path and the extra-board flow path. Therefore, the air blown out by the blower mechanism 103 circulates through the inter-board flow path and the extra-board flow path. Here, the case where the board unit 102 is a three-story board has been described, but the board unit 102 may also be one in which four or more circuit boards are stacked. The above-mentioned "other configurations of the board unit" can also be applied to a board unit 102 consisting of a three-story board or four or more circuit boards.

[0072] [Other Configurations of the Electronic Device] In electronic device 100, as described above, board unit 102 is located between blower mechanism 103 and first microphone 143, and battery 104 is located between blower mechanism 103 and second microphone 144 (see FIG. 10 ), thereby preventing the operating sound of blower mechanism 103 from being picked up by these microphones. Furthermore, the arrangement of each component in electronic device 100 can also be as follows. Figures 34 and 35 are schematic diagrams showing other configurations of the electronic device.

[0073] As shown in Fig. 34, the air blowing mechanism 103 may be disposed between the board unit 102 and the side surface 101c of the housing, rather than between the board unit 102 and the battery 104. In this case, the board unit 102 is located between the air blowing mechanism 103 and the first microphone 143, and the battery 104 is located between the air blowing mechanism 103 and the second microphone 144, preventing the operation sound of the air blowing mechanism 103 from being picked up by these microphones. Furthermore, as shown in Fig. 35, if the electronic device 100 has two air blowing mechanisms 103, one air blowing mechanism 103 may be disposed between the board unit 102 and the battery 104, and one air blowing mechanism 103 may be disposed between the board unit 102 and the side surface 101c of the housing. In this case as well, the operation sound of the air blowing mechanism 103 is prevented from being picked up by these microphones.

[0074] The electronic device 100 may further include a heat diffusion member. FIG. 36 is a schematic diagram of the electronic device 100 including the heat diffusion member 109. The heat diffusion member 109 is disposed in the extra-board flow path (see FIG. 15 ) on the rear side of the housing, and is superimposed on the board unit 102, the air blower mechanism 103, and the battery 104. The heat diffusion member 109 is a member having heat diffusion properties, such as a heat diffusion sheet or a vapor chamber. In the configuration of the electronic device 100 described above (see FIG. 10 ), heat generated in the board unit 102 circulates around the board unit 102. Therefore, by providing the heat diffusion member 109, the heat generated in the board unit 102 can be circulated throughout the entire electronic device 100, improving the heat dissipation performance of the electronic device 100.

[0075] The electronic device 100 may include a circuit board separate from the board unit 102. Fig. 37 is a schematic diagram of the electronic device 100 including a circuit board 110 separate from the board unit 102. As shown in the figure, the circuit board 110 is housed in a housing 101 and is connected to the board unit 102 by a connection board 111. Electronic components 112 that generate little heat are mounted on the circuit board 110. As described above, the board unit 102 is cooled by the air blowing mechanism 103, but the circuit board 110 does not need to be cooled by the air blowing mechanism 103 because the electronic components 112 generate little heat.

[0076] [Regarding the Electronic Device] In the above description, the electronic device 100 is described as a smartphone, but the electronic device 100 is not limited to a smartphone and may be any electronic device that includes a two-story board or a board unit in which a larger number of circuit boards are stacked and that is required to be waterproof. Specific examples include tablet terminals, cameras, game consoles, and HMDs (Head Mounted Displays).

[0077] [About the present disclosure] The effects described in this disclosure are merely examples and are not limiting, and other effects may also be present. The description of multiple effects does not necessarily mean that these effects are exhibited simultaneously. It means that at least one of the effects described above can be obtained depending on the conditions, etc., and effects not described in this disclosure may also be exhibited. Furthermore, it is possible to combine at least two of the characteristic features described in this disclosure.

[0078] The present technology can also be configured as follows.

[0079] (1) An electronic device comprising: a housing having a waterproof structure, a first substrate housed in the housing and having a first surface and a second surface opposite to the first surface, a second substrate housed in the housing and having a third surface facing the second surface and a fourth surface opposite to the third surface, electronic components mounted on at least one of the first surface, the second surface, the third surface, and the fourth surface, and a blower mechanism that generates an air flow in the inter-board flow path when the space between the second surface and the third surface is defined as an inter-board flow path. (2) The electronic device described in (1) above, wherein when at least one of the space between the first surface and the housing and the space between the fourth surface and the housing is defined as an extra-board flow path, the blower mechanism generates an air flow that passes from the blower mechanism through the inter-board flow path and the extra-board flow path and returns to the blower mechanism. (3) The electronic device according to (1) or (2), further comprising a connecting member disposed between the first substrate and the second substrate, connecting the first substrate and the second substrate, and not blocking the inter-substrate flow path. (4) The electronic device according to (3), wherein the connecting member electrically connects the first substrate and the second substrate, surrounds a space together with the first substrate and the second substrate, and has an opening that connects the inside of the space to the outside. (5) The electronic device according to (4), wherein the opening includes a first opening and a second opening, the air blowing mechanism forms a flow of air that flows into the space through the first opening and flows out of the space through the second opening, and the inter-substrate flow path is between the first opening and the second opening. (6) The electronic device according to (4) above, wherein the first substrate has a through hole provided between the first surface and the second surface, the air blowing mechanism forms a flow of air that flows into the space through the through hole and flows out of the space through the opening, and the inter-substrate flow path is between the through hole and the opening. (7) The electronic device according to any one of (1) to (6) above, further comprising a third substrate housed in the housing and having a fifth surface facing the fourth surface and a sixth surface opposite to the fifth surface, and the inter-substrate flow path is further defined between the fourth surface and the fifth surface.(8) The electronic device according to (7) above, wherein, when the space between the first surface and the housing and the space between the sixth surface and the housing are defined as extra-board flow paths, the blower mechanism forms a flow of air that passes from the blower mechanism through the inter-substrate flow path and the extra-substrate flow path and returns to the blower mechanism. (9) The electronic device according to (2) or (8) above, further comprising a heat diffusion member arranged in the extra-substrate flow path. (10) The electronic device according to any one of (1) to (9) above, wherein the inter-substrate flow path is a gap between a plurality of electronic components mounted on at least one of the second surface and the third surface. (11) The electronic device according to any one of (1) to (10) above, further comprising a microphone housed in the housing, wherein the first board and the second board are arranged between the blower mechanism and the microphone. (12) The electronic device described in (11) above, further comprising a battery housed in the housing, wherein the microphones include a first microphone arranged at one end of the housing in the longitudinal direction and a second microphone arranged at the other end of the housing in the longitudinal direction, wherein the first board and the second board are arranged between the air blowing mechanism and the first microphone, and the battery is arranged between the air blowing mechanism and the second microphone.

[0080] REFERENCE SIGNS LIST 100...Electronic device 101...Housing 102...Substrate unit 103...Ventilation mechanism 108...Heat conductive member 109...Heat diffusion member 121...First substrate 122...Second substrate 123...Connecting member 124...Electronic component 125...Wiring substrate 131...First substrate 132...Second substrate 133...Third substrate 134...First connecting member 135...Second connecting member 136...Electronic component

Claims

1. An electronic device comprising: a housing having a waterproof structure; a first substrate housed in said housing and having a first surface and a second surface opposite to said first surface; a second substrate housed in said housing and having a third surface facing said second surface and a fourth surface opposite to said third surface; electronic components mounted on at least one of said first surface, said second surface, said third surface, and said fourth surface; and, when the space between said second surface and said third surface is defined as an inter-substrate flow path, a ventilation mechanism that generates an air flow in said inter-substrate flow path.

2. An electronic device as described in claim 1, wherein when at least one of the space between the first surface and the housing and the space between the fourth surface and the housing is an off-board flow path, the blower mechanism forms a flow of air that passes from the blower mechanism through the inter-substrate flow path and the off-board flow path and returns to the blower mechanism.

3. An electronic device according to claim 1, further comprising a connecting member disposed between the first substrate and the second substrate, connecting the first substrate and the second substrate, and not blocking the flow path between the substrates.

4. An electronic device according to claim 3, wherein the connection member electrically connects the first substrate and the second substrate, encloses a space together with the first substrate and the second substrate, and has an opening that connects the inside of the space to the outside.

5. An electronic device according to claim 4, wherein the openings include a first opening and a second opening, the air blowing mechanism forms a flow of air that flows into the space through the first opening and flows out of the space through the second opening, and the inter-substrate flow path is between the first opening and the second opening.

6. An electronic device according to claim 4, wherein the first substrate has a through hole provided between the first surface and the second surface, the air blowing mechanism forms a flow of air that flows into the space through the through hole and flows out of the space through the opening, and the inter-substrate flow path is between the through hole and the opening.

7. An electronic device according to claim 1, further comprising a third substrate housed in the housing and having a fifth surface facing the fourth surface and a sixth surface opposite the fifth surface, wherein the space between the fourth surface and the fifth surface serves as a flow path between the substrates.

8. An electronic device as described in claim 7, wherein, when the space between the first surface and the housing and the space between the sixth surface and the housing are defined as off-board flow paths, the blower mechanism forms a flow of air that passes from the blower mechanism through the inter-substrate flow path and the off-board flow path and returns to the blower mechanism.

9. An electronic device according to claim 2 or 8, further comprising a heat diffusion member disposed in the external flow path of the substrate.

10. An electronic device according to claim 1, wherein the inter-substrate flow path is a gap between a plurality of electronic components mounted on at least one of the second surface and the third surface.

11. An electronic device according to claim 1, further comprising a microphone housed in the housing, wherein the first board and the second board are disposed between the air blowing mechanism and the microphone.

12. An electronic device as described in claim 11, further comprising a battery housed in the housing, wherein the microphones include a first microphone arranged at one longitudinal end of the housing and a second microphone arranged at the other longitudinal end of the housing, wherein the first board and the second board are arranged between the air blowing mechanism and the first microphone, and the battery is arranged between the air blowing mechanism and the second microphone.

Images