Electronic device

Abstract

An electronic device (100) comprises: a substrate (1); and a housing (2) which has a bottom wall (22) made of metal and has one or more holding parts (21) holding the substrate (1), and in which the substrate (1) is fixed to the bottom wall (22) by at least one fixing member. The bottom wall (22) has a hemispherical projection portion (22a) which abuts on a ground pattern (1a) of a circuit in the substrate (1). Each of the holding parts (21) has a holding protrusion portion (21a) which protrudes from the bottom wall (22) to the side on which the substrate (1) is provided, and a holding extension portion (21b) extending from an end of the holding protrusion portion (21a) with a gap from the bottom wall (22). A section of the substrate (1) held by the holding part (21) is held by being sandwiched between the holding extension portion (21b) and the bottom wall (22). The distance between the bottom wall (22) and a section of the holding extension portion (21b) where the substrate (1) abuts is smaller than the sum of the height of the projection portion (22a) and the thickness of the substrate (1). The ground pattern (1a) is pressed by the projection portion (22a).

Description

electronic equipment

[0001] The present disclosure relates to electronic devices.

[0002] Electronic devices are provided with a substrate on which a circuit is formed. The circuit is, for example, a circuit that performs signal processing. The performance of the substrate's ground is particularly important when the substrate is a high-frequency circuit board that performs signal processing for an antenna, as the performance of the substrate's ground can affect the performance of the antenna. In such electronic devices, to ensure stable performance of the substrate's ground, the ground pattern of the substrate's circuit is connected to the housing, which serves as the frame ground and houses the substrate.

[0003] The configuration of an electronic device has been disclosed in which an electronic board and a cover, which is part of a housing, are connected by a fastening member (see, for example, Patent Document 1). The electronic device disclosed in Patent Document 1 includes an electronic board and a metal cover that holds the electronic board. The cover has a first guide portion and a second guide portion to guide the electronic board to a position where it will be fastened with screws. The first guide portion protrudes from a flat portion of the cover. The second guide portion is inclined and spaced apart from the first guide portion, and an insertion opening for inserting the electronic board is formed between the first guide portion and the second guide portion. The electronic board inserted via the first guide portion and the second guide portion is fixed to the cover by a screw, and the ground pattern of the electronic board is connected to the cover, which is the frame ground.

[0004] Japanese Patent Application Laid-Open No. 2017-5060

[0005] In the above-mentioned Patent Document 1, the ground pattern of the electronic board and the cover, which is the frame ground, are connected only at the screw fastening point. Therefore, in the disclosed configuration, the ground performance of the board is ensured only at this point. The first guide portion and the second guide portion only have the function of guiding the electronic board to the fastening position and are not involved in ensuring the ground performance of the board. The ground performance of the board is ensured only by a small rotation angle before full fastening, when the fastening by the screw generates axial force. Therefore, there was a problem that the ground performance of the board remained unstable.

[0006] Therefore, an object of the present disclosure is to obtain an electronic device that ensures stable performance of the ground of the board at low cost.

[0007] The electronic device of the present disclosure includes a substrate having a plate surface extending in a first direction and a second direction perpendicular to the first direction and on which a circuit is formed, a bottom wall made of metal facing one plate surface of the substrate, and a housing having one or more holding portions that hold a portion of the substrate on one side in the first direction, and a portion of the substrate on the other side in the first direction fixed to the fixing portion of the bottom wall by at least one fixing member, wherein the bottom wall has a hemispherical protrusion that protrudes toward the one plate surface from a portion that is on the one side in the first direction of the fixing portion and that is facing the one plate surface of the substrate on the other side in the first direction of the holding portion, and that abuts against a ground pattern of the circuit provided on the one plate surface. The holding portion is provided on the bottom wall and has a holding protrusion portion that protrudes from the bottom wall toward the side where the substrate is provided, and a holding extension portion that extends from the end of the holding protrusion portion toward the other side of the first direction with a gap between it and the bottom wall, the portion of the substrate held by the holding portion is held by being sandwiched between the holding extension portion and the bottom wall, the distance between the portion of the holding extension portion that abuts the substrate and the bottom wall is smaller than the sum of the height of the protrusion portion from the bottom wall and the thickness of the substrate, the substrate is fixed to the housing by pressure from the holding extension portion, pressure from the protrusion portion, and pressure from the fixing member, and the ground pattern is pressed against the protrusion portion.

[0008] According to the electronic device of the present disclosure, the bottom wall has a hemispherical protrusion that protrudes toward one plate surface from a portion facing one plate surface of the substrate on the other side of the holding portion in the first direction, the hemispherical protrusion abutting a ground pattern of a circuit provided on the one plate surface, the portion of the substrate held by the holding portion is sandwiched and held between the holding extension and the bottom wall, the distance between the abutting portion of the substrate and the bottom wall is less than the sum of the height of the protrusion from the bottom wall and the thickness of the substrate, the substrate is fixed to the housing by pressure from the holding extension, pressure from the protrusion, and pressure from the fixing member, and the ground pattern is pressed against the protrusion, so that the reaction force of the bending stress generated in the substrate due to the fixing of the substrate at the fixing portion by the fixing member becomes a high contact pressure on the ground pattern of the protrusion of the housing, thereby ensuring stable grounding performance of the substrate. Furthermore, because the high contact pressure is generated by at least one fixing member, stable grounding performance of the substrate can be ensured at low cost. Furthermore, since the protrusions are hemispherical, they do not damage the ground pattern, ensuring stable ground performance for the board.

[0009] Fig. 2 is a plan view showing an outline of an electronic device according to embodiment 1. Fig. 3 is a cross-sectional view showing an outline of the electronic device cut at the A-A cross-sectional position in Fig. 1. Fig. 4 is a cross-sectional view showing a schematic outline of a main part of the electronic device according to embodiment 1. Fig. 5 is a cross-sectional view illustrating the fixing of a substrate of the electronic device according to embodiment 1. Fig. 6 is another plan view showing an outline of the electronic device according to embodiment 1. Fig. 7 is a plan view showing an outline of an electronic device of a comparative example.

[0010] Hereinafter, electronic devices according to embodiments of the present disclosure will be described with reference to the drawings. Note that the same or equivalent members and parts in each drawing will be denoted by the same reference numerals.

[0011] Embodiment 1. FIG. 1 is a plan view showing an outline of electronic device 100 according to embodiment 1, omitting a right-side portion of electronic device 100 that is not essential to the present disclosure. FIG. 2 is a cross-sectional view showing an outline of electronic device 100 cut at the A-A cross-section position in FIG. 1. FIG. 3 is a cross-sectional view showing an outline of essential parts of electronic device 100, with protrusion 22a moved toward holding portion 21 and an enlarged view of the area surrounding holding portion 21. FIG. 4 is a cross-sectional view illustrating the fixation of substrate 1 of electronic device 100, cut at the same position as FIG. 2. FIG. 5 is another plan view showing an outline of electronic device 100, with antenna element 4 removed from FIG. 1, illustrating an example of the configuration of the arrangement of each part. FIG. 6 is a plan view showing an outline of electronic device 101 of a comparative example, with antenna element 4 and connector 7 removed and an enlarged view of the area surrounding the portion holding substrate 1. Electronic device 100 is, for example, a signal processing device incorporating a signal processing circuit. Electronic device 100 is, for example, a device mounted on a vehicle for use. In the figure, the X direction is a first direction, X1 is one side of the first direction, and X2 is the other side of the first direction. The Y direction is a second direction perpendicular to the first direction, Y1 is one side of the second direction, and Y2 is the other side of the second direction. The Z direction is a third direction perpendicular to the first and second directions.

[0012] <Electronic Device 100> As shown in FIG. 1 , the electronic device 100 includes a substrate 1 having a surface extending in a first direction and a second direction perpendicular to the first direction and on which a circuit is formed, a metal bottom wall 22 facing one surface 1b (not shown in FIG. 1 ) of the substrate 1, and a housing 2 having one or more holding portions 21 that hold a portion of the substrate 1 on one side in the first direction. As shown in FIG. 2 , the portion of the substrate 1 on the other side in the first direction is fixed by at least one fixing member, i.e., a fixing portion 22b of the bottom wall 22. In this embodiment, the fixing member is a screw 3. The bottom wall 22 is made of, for example, aluminum. As shown in FIG. 1 , the bottom wall 22 has side walls 22c that cover each of the portions of the substrate 1 on one side and the other side in the second direction.

[0013] The electronic device 100 shown in this embodiment further includes an antenna element 4 and a connector 7 connected to the circuit. The antenna element 4 is connected to the circuit of the substrate 1 by soldering at a feed point 6. The antenna element 4 extends in a third direction and then in a first direction. A signal received from a radio wave by the antenna element 4 is transmitted to the circuit of the substrate 1 via the feed point 6. The signal processed by the circuit is output from the connector 7 to the outside of the electronic device 100. The configuration of the electronic device 100 is not limited to this, and it may be a configuration that does not include the antenna element 4 and the connector 7. In this embodiment, since the substrate 1 has the connector 7, the portion of the substrate 1 where the connector 7 is provided protrudes to one side in the first direction and has a stepped configuration, and the stepped portion of the substrate 1 is held by a holding portion 21. The shape of the substrate 1 is not limited to this, and may be rectangular, square, or other shapes. If the shape of the substrate 1 is rectangular or square, the end of the substrate 1 on one side in the first direction is held by a holding portion 21.

[0014] In this embodiment, the housing 2 has two holding portions 21. The number of holding portions 21 is not limited to this, and may be one or more. The number and arrangement of the holding portions 21 and fixing portions 22b for stably fixing the substrate 1 to the housing 2 at low cost will be described later.

[0015] In this embodiment, one fixing member is provided, and the fixing member is a screw 3. The number of fixing members is not limited to one, and multiple fixing members may be used. As long as the substrate 1 can be stably fixed by one fixing member, only one fixing member is required. Reducing the number of fixing members reduces the number of components constituting the electronic device 100, thereby reducing the cost of the electronic device 100. Furthermore, reducing the number of fixing members reduces the number of processes for fixing using the fixing members, thereby improving the productivity of the electronic device 100. The fixing member is not limited to a screw, and other members, such as clips, may be used as long as they can fix the substrate 1 to the bottom wall 22. When the fixing member is a screw, the substrate 1 can be easily and stably fixed to the bottom wall 22. In this embodiment, a female thread penetrating the bottom wall 22 is provided in the bottom wall 22, and the screw 3 is fastened to the bottom wall 22. A through-hole may be provided in the bottom wall 22, and the screw 3 may be fastened to a nut.

[0016] <Ground Connection> The connection between the circuit ground pattern 1a of the substrate 1 and the housing 2, which serves as the frame ground supporting the substrate 1 and is a key component of this disclosure, will now be described. The ground performance of the substrate 1 is particularly important when the substrate 1 is a high-frequency circuit board that processes signals for an antenna. This is because the ground performance of the substrate 1 can affect the performance of the antenna. In the electronic device 100, to ensure stable ground performance of the substrate 1, the ground pattern 1a of the circuit of the substrate 1 is connected to the housing 2, which serves as the frame ground supporting the substrate 1, via a ground contact 5, as shown in FIG. 3 . A reliable connection between the substrate 1 and the housing 2 via the ground contact 5 is important for stable antenna performance. To ensure stable ground performance, the ground pattern 1a of the circuit of the substrate 1 is pressed against a hemispherical protrusion 22a on the bottom wall 22 at the ground contact 5 with a high contact pressure. Details will be described below.

[0017] As shown in Fig. 2, the bottom wall 22 has a hemispherical protrusion 22a that protrudes from a portion facing one plate surface 1b of the substrate 1 on one side of the fixing portion 22b in the first direction and on the other side of the holding portion 21 in the first direction toward the one plate surface 1b and abuts against a ground pattern 1a (not shown in Fig. 2) of a circuit provided on the one plate surface 1b. The holding portion 21 is provided on the bottom wall 22 and has a holding protrusion 21a that protrudes from the bottom wall 22 toward the side on which the substrate 1 is provided, and a holding extension 21b that extends from an end of the holding protrusion 21a toward the other side in the first direction, leaving a gap between it and the bottom wall 22. The portion of the substrate 1 held by the holding portion 21 (substrate holding portion 1d) is sandwiched and held between the holding extension 21b and the bottom wall 22.

[0018] 3, the distance between the portion of the substrate 1 where the holding extension 21b abuts and the bottom wall 22 (hereinafter, this distance will be referred to as D1) is smaller than the sum of the height of the protrusion 22a from the bottom wall 22 and the thickness of the substrate 1 (hereinafter, this sum will be referred to as D2). The substrate 1 is fixed to the housing 2 by pressure from the holding extension 21b, pressure from the protrusion 22a, and pressure from the screw 3, which is a fixing member. The ground pattern 1a is pressed against the protrusion 22a.

[0019] Because D1 is smaller than D2, when the substrate 1 is inserted into the holder 21 during installation in the housing 2, one plate surface 1b of the substrate 1 comes into contact with the protrusion 22a, causing the substrate 1 to tilt as shown by the dashed line in FIG. 4 . From this state, the substrate 1 is fixed at the fixing portion 22b with the screw 3 in the direction of the arrow shown in FIG. 4 . Fixing the substrate 1 at the fixing portion 22b generates bending stress in the substrate 1. Fixing the substrate 1 at the fixing portion 22b with the fixing member generates a reaction force of the bending stress generated in the substrate 1, which becomes a high contact pressure of the protrusion 22a of the housing 2 against the ground pattern 1a, thereby ensuring stable grounding performance of the substrate 1. Furthermore, because a high contact pressure is generated by at least one fixing member, stable grounding performance of the substrate 1 can be ensured at low cost. Furthermore, because the protrusion 22a is hemispherical, it does not damage the ground pattern 1a, thereby ensuring stable grounding performance of the substrate 1.

[0020] In this embodiment, the holding protrusion 21 a of the holding portion 21 is integrated with the bottom wall 22. The housing 2 shown in FIG. 2 can be formed by forming the holding portion 21 and the bottom wall 22 from a single metal plate and bending the portion of the holding protrusion 21 a of the holding portion 21 on the bottom wall 22 side in a direction perpendicular to the first direction and the second direction. The configuration is not limited to the holding protrusion 21 a of the holding portion 21 being integrated with the bottom wall 22, and the holding portion 21 and the bottom wall 22 may be separate. The separate holding portion 21 may be fixed to the bottom wall 22 with, for example, a screw. When the holding protrusion 21 a of the holding portion 21 is integrated with the bottom wall 22, a process for connecting the holding protrusion 21 a and the bottom wall 22 is not required, thereby improving the productivity of the electronic device 100.

[0021] <Tapered Surface 21b1> In this embodiment, the holding extension 21b has a tapered surface 21b1 on the bottom wall 22 side, where the distance from the bottom wall 22 increases with increasing distance from the holding protrusion 21a. Because D1 is smaller than D2, the force of the substrate 1 lifting in the third direction is absorbed by the holding extension 21b against which the substrate 1 abuts. By providing the tapered surface 21b1 on the holding extension 21b, the distance between the holding extension 21b and the bottom wall 22 is not constant, so D1 is a value with a range. Because D1 is variable on the tapered surface 21b1, the tapered surface 21b1 can accommodate tolerances in various components, such as the thickness of the substrate 1 and the height and outer diameter of the hemispherical protrusion 22a. Because the tapered surface 21b1 absorbs the tolerances in various components, the grounding performance of the substrate 1 can be more reliably ensured. The corner 1e of the substrate 1 may abut on any part of the tapered surface 21b1 as long as it is within the range of D1, which is smaller than D2.

[0022] Furthermore, by fastening the screw 3 to the fixing portion 22b, the substrate 1 is pushed out toward the holding portion 21, thereby enabling the substrate 1 to be securely abutted against the tapered surface 21b1. The holding extension 21b also prevents the substrate 1 from floating up, ensuring contact pressure between the substrate 1 and the protrusion 22a, and contributing to stabilizing the grounding performance of the substrate 1. Specifically, because D1 is smaller than D2, the tapered surface 21b1 absorbs the dimensional tolerances of each part, and the substrate 1 is pushed out toward the tapered surface 21b1 when the screw is fastened, allowing the substrate 1 to be securely fixed to the housing 2.

[0023] <Arrangement of Protrusion 22a> The arrangement of the protrusion 22a will be described. In this embodiment, the protrusion 22a is provided on a portion of the bottom wall 22 closer to the holding portion 21 than the central portion in the first direction between the fixing portion 22b and the holding portion 21. The closer the protrusion 22a is to the holding portion 21, the greater the lift of the other side of the substrate 1 in the first direction shown in FIG. 4 . The greater the lift of the other side of the substrate 1 in the first direction, the greater the bending stress generated in the substrate 1. Therefore, by providing the protrusion 22a on a portion of the bottom wall 22 closer to the holding portion 21 than the central portion in the first direction between the fixing portion 22b and the holding portion 21, it is possible to reliably ensure a high contact pressure of the protrusion 22a against the ground pattern 1a. In this way, by changing the arrangement of the protrusion 22a to one side or the other side in the first direction, the contact pressure of the protrusion 22a at the ground contact 5 can be adjusted.

[0024] If the contact pressure of the protrusion 22a at the ground contact 5 becomes excessive and there is a risk of cracking the solder on the substrate 1, it is desirable to position the protrusion 22a closer to the center in the first direction between the fixing portion 22b and the holding portion 21. In Patent Document 1, ground performance is ensured by fastening screws. In the configuration of the present disclosure, the design adjustment margin for ensuring ground performance can be made larger than in the configuration of Patent Document 1. In addition, the manufacturing tolerance can be set larger than in the configuration of Patent Document 1.

[0025] The protrusion 22a and the ground pattern 1a still abut against each other even when the protrusion 22a is provided on a portion of the bottom wall 22 closer to the fixed portion 22b than to the central portion in the first direction between the fixed portion 22b and the holding portion 21. However, since the bending stress of the substrate 1 caused by the fastening force of the screw 3 is less likely to be transmitted to the hemispherical protrusion 22a, it becomes impossible to ensure a high contact pressure at the ground contact 5 of the protrusion 22a, and therefore care must be taken when arranging the protrusion 22a.

[0026] In this embodiment, the protrusions 22 a are formed by pressing the portion of the bottom wall 22 opposite to the side where the substrate 1 is provided. By forming the protrusions 22 a in this manner, the protrusions 22 a can be easily formed at the desired positions. The method for forming the protrusions 22 a is not limited to this, and the protrusions 22 a may also be formed by joining a hemispherical metal member to the bottom wall 22.

[0027] <Number and Arrangement of Retaining Portions 21 and Fixing Portions 22b> The number and arrangement of retaining portions 21 and fixing portions 22b that stably and inexpensively fix the substrate 1 to the housing 2 will be described with reference to FIG. 5 . In this embodiment, the substrate 1 has a connector 7 connected to a circuit on one side of the other plate surface 1c of the substrate 1 in the first direction. One retaining portion 21 is provided on each of the portions of the bottom wall 22 on one side of the connector 7 in the second direction and on the other side of the second direction. One protrusion 22a is provided on each portion of the bottom wall 22 adjacent to each retaining portion 21. In FIG. 5 , the protrusion 22a is indicated by a dotted line. The substrate 1 is fixed at the fixing portion 22b by a screw 3, which is a single fixing member. The distances between the fixing portion 22b and the two retaining portions 21 are equal, and the fixing portion 22b and the two retaining portions 21 form an isosceles triangle. In FIG. 5, the fixed portion 22b is indicated by a broken line, and an isosceles triangle is indicated by a dashed line.

[0028] There are at least three fixing points required to stably support the flat substrate 1. In the example of electronic device 100 shown in FIG. 5 , the substrate 1 is fixed to the housing 2 at three fixing points. The three fixing points are two holding portions 21 and one fixing portion 22b. By configuring the fixing portion 22b and the two holding portions 21 so that the distances between them are equal and the fixing portion 22b and the two holding portions 21 form an isosceles triangle, it is possible to generate uniform contact pressure on the two protrusions 22a by fixing with one screw 3. Because uniform contact pressure is generated on the two protrusions 22a, the grounding performance of the substrate 1 can be stably ensured at low cost.

[0029] The reason for setting the fixing points in this manner will be explained. When the protrusion 22a where the ground contact 5 is formed and the power supply point 6 are arranged at opposite ends in the longitudinal direction of the board 1, taking into consideration the positional relationship with the holding part 21, the fixing part 22b where the screw 3 is fastened is set on the side of the power supply point 6, and the holding part 21 is set on the side of the protrusion 22a. When the board 1 is small, the connector 7 is set to be located at the opposite end in the longitudinal direction of the board 1 from the power supply point 6 due to the component configuration, and in relation to the fixing points that support the board 1, two fixing points are set on both sides of the connector 7 in the second direction.

[0030] When all three fixing points of the board 1 are fastened with screws, the posture of the board 1 and the contact pressure at the ground contacts 5 change depending on the order in which the screws are fastened, so it is necessary to confirm whether the required contact pressure is secured at each ground contact 5. By using the retaining portion 21 and the protrusion 22a as the two fixing points on both sides of the connector 7 in the second direction, there is an advantage in that the required contact pressure can be equalized and applied simultaneously to the two fixing points simply by fastening the fixing points corresponding to the vertices of an isosceles triangle with the screws 3. Note that the configuration is not limited to one in which both of the two protrusions 22a abut against the ground pattern 1a of the board 1, and a configuration in which either one of the two protrusions 22a abuts against the ground pattern 1a of the board 1 may be acceptable depending on the circuit configuration of the board 1.

[0031] <Comparative Example> The configuration of electronic device 100 described in the present disclosure will be compared with the configuration of electronic device 101 of a comparative example using Figure 6. Portions of the configuration of electronic device 100 that differ from electronic device 101 are indicated by dashed lines. Electronic device 101 of the comparative example does not have holding portion 21, and ground pattern 1a (not shown in Figure 6) and bottom wall 22 are connected by fastening with screws 3a.

[0032] If the fastening of the retaining portion 21 is changed to using the screw 3a, the portion of the bottom wall 22 on the other side in the second direction will be larger by the length of the width H shown in Figure 6. By changing from fastening using the screw 3a to ground connection using the retaining portion 21 and the protrusion 22a, the size of the portion in the second direction of the housing 2 can be reduced. Furthermore, because the screw 3a is no longer necessary, the number of parts is reduced and the assembly man-hours are also reduced, which allows for a reduction in the cost of the electronic device 100 and an improvement in the productivity of the electronic device 100.

[0033] As described above, in the electronic device 100 according to the first embodiment, the bottom wall 22 has a hemispherical protrusion 22a that protrudes from a portion of the bottom wall 22 that is on one side of the fixing portion 22b in the first direction and faces one plate surface 1b of the substrate 1 on the other side of the holding portion 21 in the first direction, toward the one plate surface 1b, and abuts against the ground pattern 1a of the circuit provided on the one plate surface 1b. The portion of the substrate 1 held by the holding portion 21 is sandwiched and held between the holding extension 21b and the bottom wall 22, and the distance between the abutting portion of the holding extension 21b of the substrate 1 and the bottom wall 22 is is smaller than the sum of the height of the protrusion 22a from the bottom wall 22 and the thickness of the substrate 1, and the substrate 1 is fixed to the housing 2 by pressure from the holding extension 21b, pressure from the protrusion 22a, and pressure from the screw 3, which is a fixing member, and the ground pattern 1a is pressed against the protrusion 22a. Therefore, when the substrate 1 is fixed at the fixing portion 22b of the fixing member, the reaction force of the bending stress generated in the substrate 1 becomes a high contact pressure of the protrusion 22a of the housing 2 against the ground pattern 1a, thereby stably ensuring the grounding performance of the substrate 1. Furthermore, because a high contact pressure is generated by at least one fixing member, the grounding performance of the substrate 1 can be stably ensured at low cost. Furthermore, because the protrusion 22a is hemispherical, it will not damage the ground pattern 1a, and the grounding performance of the substrate 1 can be stably ensured.

[0034] When the holding protrusion 21 a of the holding portion 21 is integrated with the bottom wall 22, a process for connecting the holding protrusion 21 a to the bottom wall 22 is not required, thereby improving the productivity of the electronic device 100. When the fixing member is a screw 3, the substrate 1 can be easily and stably fixed to the bottom wall 22.

[0035] When the holding extension 21b has a tapered surface 21b1 on the bottom wall 22 side, the distance between the holding extension 21b and the bottom wall 22 increases with increasing distance from the holding protrusion 21a. This allows the distance between the holding extension 21b and the bottom wall 22 to vary along the tapered surface 21b1, thereby accommodating the tolerances of various components, such as the thickness of the substrate 1 and the height and outer diameter of the hemispherical protrusion 22a. Because the tapered surface 21b1 absorbs the tolerances of various components, the grounding performance of the substrate 1 can be more reliably ensured. Furthermore, by fastening the screw 3 to the fixing portion 22b, the substrate 1 is pushed toward the holding portion 21, ensuring reliable contact between the substrate 1 and the tapered surface 21b1.

[0036] When the protrusion portion 22a is provided in a portion of the bottom wall 22 closer to the holding portion 21 than the central portion in the first direction between the fixing portion 22b and the holding portion 21, a high load contact pressure of the protrusion portion 22a against the ground pattern 1a can be reliably ensured.

[0037] When one retaining portion 21 is provided on each of the portions of the bottom wall 22 on one side of the connector 7 in the second direction and on the other side of the second direction, one protrusion 22a is provided on each of the portions of the bottom wall 22 adjacent to each of the retaining portions 21, the substrate 1 is fixed at the fixing portion 22b with a single fixing member, that is, a screw 3, the distance between the fixing portion 22b and each of the two retaining portions 21 is equal, and an isosceles triangle is formed by the fixing portion 22b and the two retaining portions 21, uniform contact pressure can be generated on the two protrusions 22a by fixing at one location with the screw 3, and therefore the grounding performance of the substrate 1 can be stably ensured at low cost.

[0038] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0039] 1 Board, 1a Ground pattern, 1b One plate surface, 1c Other plate surface, 1d Board holding portion, 1e Corner portion, 2 Housing, 21 Holding portion, 21a Holding protrusion, 21b Holding extension portion, 21b1 Tapered surface, 22 Bottom wall, 22a Protrusion, 22b Fixing portion, 22c Side wall, 3, 3a Screw, 4 Antenna element, 5 Ground contact, 6 Power supply point, 7 Connector, 100 Electronic device, 101 Electronic device

Claims

1. A housing comprising: a substrate having a surface extending in a first direction and a second direction perpendicular to the first direction, and on which a circuit is formed; a bottom wall made of metal facing one surface of the substrate; and one or more holding portions holding a portion of the substrate on one side in the first direction, the portion of the substrate on the other side in the first direction being fixed to the fixing portion of the bottom wall by at least one fixing member; the bottom wall having a hemispherical protrusion that protrudes toward the one surface of the substrate from a portion facing the one surface of the substrate on the other side in the first direction relative to the fixing portion and that abuts against a ground pattern of the circuit provided on the one surface of the substrate; the holding portion having a holding protrusion that is provided on the bottom wall and protrudes from the bottom wall toward the side where the substrate is provided, and a holding extension that extends from an end of the holding protrusion toward the other side in the first direction with a gap between it and the bottom wall; an electronic device in which the portion of the substrate held by the holding portion is sandwiched and held between the holding extension portion and the bottom wall, the distance between the portion of the substrate abutting the holding extension portion and the bottom wall is smaller than the sum of the height of the protrusion from the bottom wall and the thickness of the substrate, the substrate is fixed to the housing by pressure from the holding extension portion, pressure from the protrusion portion, and pressure from the fixing member, and the ground pattern is pressed against the protrusion portion.

2. The electronic device according to claim 1, wherein the holding protrusion of the holding portion is integrated with the bottom wall.

3. The electronic device according to claim 1, wherein the fixing member is a screw.

4. An electronic device according to any one of claims 1 to 3, wherein the holding extension has a tapered surface on the side of the bottom wall, the distance between the holding extension and the bottom wall increasing as the distance from the holding protrusion increases.

5. An electronic device as described in any one of claims 1 to 3, wherein the protrusion portion is provided on a portion of the bottom wall closer to the holding portion than the central portion in the first direction between the fixing portion and the holding portion.

6. An electronic device as claimed in any one of claims 1 to 3, wherein the substrate has a connector connected to the circuit on one side of the other plate surface of the substrate in the first direction, the holding portions are provided one on each side of the bottom wall in the second direction and the other side in the second direction, sandwiching the connector, the protrusion portions are provided one on each part of the bottom wall adjacent to each of the holding portions, the substrate is fixed to the fixing portions by one of the fixing members, the distance between the fixing portion and each of the two holding portions is equal, and the fixing portion and the two holding portions form an isosceles triangle.

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