Electronic device

Abstract

To provide an electronic apparatus capable of efficiently dissipating heat from a semiconductor element mounted on a substrate without deteriorating a performance of holding the substrate with an adhesive.SOLUTION: An electronic apparatus includes a substrate on which a semiconductor element is mounted on a first surface, and a holding member that is adhered to a second surface opposite to the first surface of the substrate and holds the substrate, the second side of the substrate includes a first region to which the holding member is fixed via an adhesive, a second region in which a conducting portion that conducts heat from the semiconductor element from the first surface to the second surface of the substrate is arranged, and a third region in which the portion of the holding member is in contact with the substrate. The second region is provided between the first region and the third region in a planar direction of the second surface.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to an electronic device having a substrate on which semiconductor elements are mounted.

Background Art

[0002] For example, in an imaging device such as a single-lens type digital camera, in order to achieve miniaturization and thinning, there is an imaging device that does not include a reflex mirror that guides the light beam from the subject obtained through the imaging optical system to the viewfinder optical system. In this type of imaging device, the display unit provided in the imaging device functions as a viewfinder, the imaging element is constantly driven to perform image processing, and a live view image is displayed on the display unit.

[0003] Therefore, in an imaging device that does not include a reflex mirror, the time during which heat is generated from the imaging element and the IC for image processing is longer than that in an imaging device that includes a reflex mirror. As an influence of heat on the imaging element, it is generally known that the image quality deteriorates due to an increase in signal noise of the imaging element.

[0004] In order to avoid the above event, for example, a technique has been proposed in which a heat absorption part is provided on the substrate on which the imaging element is mounted, and a heat dissipation member is brought into contact with the heat absorption part to efficiently dissipate the heat of the imaging element to the outside (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the technique disclosed in the above-mentioned patent document, the side surface of the package of the imaging element is adhered to the holder for heat dissipation. Therefore, the heat dissipation performance of the imaging element, which is a semiconductor element, is reduced by using an adhesive, which is a non-metallic material.

[0007] The present invention has been made in view of the above circumstances, and provides an electronic device capable of efficiently dissipating heat from a semiconductor element mounted on a substrate without degrading the holding performance of the substrate by an adhesive.

Means for Solving the Problems

[0008] An electronic device as an example of the present invention includes a substrate on which a semiconductor element is mounted on a first surface , in which a conductor layer and an internal insulating layer are alternately laminated and a holding member configured to be bonded to a second surface, which is the opposite surface of the first surface of the substrate, to hold the substrate. in The second surface of the substrate includes On the second surface of the substrate, a conductor layer and a surface insulating layer covering the surface thereof are formed. a first region to which the holding member is fixed via an adhesive, a second region in which a conduction portion for guiding heat of the semiconductor element from the first surface to the second surface of the substrate is disposed, and a third region in which a part of the holding member is in direct contact with the substrate. In the planar direction of the second surface, the second region is provided between the first region and the third region. In the planar direction of the second surface, the second region is provided between the first region and the third region. The third region, the second region, and the first region are The conductor layer and the surface insulating layer covering the surface thereof configured and arranged along the outer edge of the substrate. The third region is disposed closer to the outer edge of the substrate than the adjacent second region, and the second region is disposed closer to the outer edge of the substrate than the adjacent first region. The 1 area region and the 2 areas region and the holding member are fixed to the holding member by attaching an adhesive thereto, and the third region is configured to directly contact the holding member without passing through the adhesive. This is a feature.

Effects of the Invention

[0009] According to the electronic device which is an example of the present invention, heat dissipation of the semiconductor element mounted on the substrate can be efficiently performed without degrading the holding performance of the substrate by the adhesive.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 11

Embodiments for Carrying Out the Invention

[0011] Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. In each figure, the same elements are denoted by the same reference numerals, and redundant descriptions are all omitted. Note that the shapes, dimensions, etc. of the elements shown in the drawings are schematically shown and do not indicate actual shapes, dimensions, etc.

[0012] In the drawings, an XYZ coordinate system is shown as a three-dimensional orthogonal coordinate system as appropriate. In the XYZ coordinate system, the Z direction is a direction parallel to the optical axis OA described later. The X direction is a direction orthogonal to the Z direction and corresponds to the substantially left-right direction in FIG. 1. The Y direction is a direction orthogonal to both the X direction and the Z direction and corresponds to the up-down direction in FIG. 1.

[0013] FIG. 1 is an external perspective view of the camera 100 from the front side. The camera 100 is an example of an electronic device and is covered by an upper surface cover 101, a front cover 102, and a rear cover 103 which are exterior members. The upper surface cover 101 is provided with a release button 104, an electronic dial 105, a grip 106, a mount 107, and a mode dial 108.

[0014] The release button 104 is a button that receives an imaging instruction for the camera 100. When an operation of pressing the release button 104 is received, the camera 100 drives each part to execute an imaging operation. The electronic dial 105 is an operation member that receives an input of imaging settings for the camera 100. By operating the electronic dial 105, arbitrary imaging parameters such as exposure settings can be set. The grip 106 is a part where the user grips the camera 100 when imaging a subject. A lens (not shown) is attached to the mount 107. The mode dial 108 is an operation member that receives an operation for changing the imaging mode. After the user sets the imaging conditions of the camera 100 via the above operation members, the camera 100 performs imaging of a moving image or a still image.

[0015] Next, the internal structure of the camera 100 will be described. FIG. 2 is an exploded perspective view of the camera 100 from the front side with the exterior members removed. FIG. 3 is an exploded perspective view of the camera 100 from the rear side with the exterior members removed.

[0016] Inside the camera 100, a mount 107, a main base 200, a shutter unit 300, an imaging unit 400, and a control board 500 are arranged in order from the front side to the rear side.

[0017] The main base 200 is a member that forms the framework of the camera 100 and is composed of a material such as resin. The shutter unit 300 is a light-shielding member used for exposure control of the imaging unit 400 and is fixed to the main base 200 with screws (not shown) or the like.

[0018] The imaging unit 400 includes an image sensor 401 for imaging an image of a subject on the front side. The imaging unit 400 is adjusted with respect to the mount 107 so that the imaging surface of the image sensor 401 is parallel with a predetermined interval and is fixed within the camera 100. Further, the imaging unit 400 is electrically connected to the control board 500 via a flexible printed wiring board 408 on the back side. Thereby, the image of the subject formed on the imaging surface is converted into an electrical signal by the image sensor 401, and the electrical signal is transmitted to the control board 500 via the flexible printed wiring board 408.

[0019] The control board 500 has an image processing IC 501 that performs various image processes. The control board 500 converts the electrical signal output from the flexible printed wiring board 408 into an image and presents the image to the user via, for example, a liquid crystal display device (not shown).

[0020] FIG. 4 is an exploded perspective view of the imaging unit 400 as viewed from the back direction. The imaging unit 400 includes an optical filter unit 409 and an image sensor 401. The optical filter unit 409 is disposed on the front side of the image sensor 401 and includes, for example, an optical low-pass filter or the like. Note that the optical filter unit 409 may include a piezoelectric element for vibrating and removing dust or the like attached to the filter surface.

[0021] The imaging element 401 has a photoelectric conversion unit (not shown) in which a plurality of pixels are arranged in the plane direction of the imaging surface, and is mounted on the imaging substrate 402. Each pixel of the photoelectric conversion unit includes a photodiode or the like that detects light and generates electric charges. Further, the imaging element 401 has electrode pads 403 on the back side which is the back surface on the subject side. The electrode pads 403 are electrically connected to the photoelectric conversion unit of the imaging element 401. Note that the imaging element 401 of the present embodiment is, as an example, a CMOS image sensor, but is not limited thereto, and may be other imaging devices such as a CCD.

[0022] The imaging substrate 402 is electrically connected to the photoelectric conversion unit of the imaging element 401 via the electrode pads 403, and receives an electrical signal from the imaging element 401. On the back side of the imaging substrate 402, various electronic components 402a such as capacitors mounted on the imaging substrate 402 and a connector 407 electrically connected to the flexible printed wiring board 408 are mounted.

[0023] The imaging unit 400 of the present embodiment has a structure of the LLCC (Lead Less Chip Carrier) type in which the electrode pads 403 are provided on the back surface of the imaging element 401 and leads are not led out to the outside of the imaging element 401. Note that instead of the LLCC type, for example, a structure of the surface mount type in which leads are sandwiched between ceramic plates and a gap is formed between the imaging element 401 and the imaging substrate 402 for soldering may be adopted for the imaging unit 400.

[0024] The imaging substrate 402 is held by a holding member 404. Further, on the back side of the holding member 404, an image blur correction unit 410 that corrects blur by translating or rotating the holding member 404 holding the imaging element 401 and the imaging substrate 402 on the XY plane is arranged.

[0025] Here, the holding member 404 is made of a metal material. Thereby, the heat of the imaging substrate 402 on which the imaging element 401 is mounted is easily transferred to the holding member 404 in contact with the imaging substrate 402, and the effect of reducing the heat of the imaging element 401 is easily obtained.

[0026] Next, the method for fixing the imaging substrate 402 will be described. FIG. 5 is a longitudinal sectional view in the YZ plane of the imaging unit 400. FIG. 6 is a partial enlarged view of the region indicated by the broken line in FIG. 5, showing the region where the imaging substrate 402 and the holding member 404 are in contact.

[0027] The imaging substrate 402 on which the imaging element 401 is mounted is abutted against the holding member 404 in the optical axis OA direction (Z direction). Thereby, the imaging substrate 402 and the holding member 404 are in close contact with each other. In the above-described close contact state, an adhesive 405 injected by a dispenser (not shown) or the like is applied so as to adhere to both the imaging substrate 402 and the holding member 404. Then, the imaging substrate 402 and the holding member 404 are fixed to each other by the adhesive 405. In the present embodiment, for example, by applying an ultraviolet curable resin as the adhesive 405, the adhesive 405 can be cured in a short time to shorten the required time for the adhesion process. Note that the adhesive 405 is not limited to the ultraviolet curable resin, and other materials may be used.

[0028] Next, the wiring of the imaging substrate 402 will be described. FIG. 7 is a diagram showing an example of the wiring of the imaging substrate 402 on the back side. FIG. 8 is a partial enlarged view showing the region where a cutout is provided in the conductor in FIG. 7. FIG. 9 is a longitudinal sectional view in the YZ plane of the imaging substrate 402.

[0029] The imaging substrate 402 on which the imaging element 401 is mounted is a multilayer printed wiring board having an overall substantially rectangular shape. As shown in FIG. 9, the imaging substrate 402 has a configuration including a plurality of conductor layers P1 to Pn and one or more internal insulating layers K1 to K(n - 1) (where n is an integer of 2 or more). An internal insulating layer is disposed between each conductor layer of the imaging substrate 402, and the conductor layers and the internal insulating layers are alternately laminated in the Z direction. Further, a surface insulating layer (resist) R is formed on the surface of the conductor layer Pn located on the back side. Note that FIG. 9 shows a configuration example of the imaging substrate 402 in which there are 4 conductor layers and 3 internal insulating layers (that is, n = 4).

[0030] On the front side of the imaging substrate 402, a plurality of electrode pads 406 are arranged at the mounting positions of the imaging elements 401. The electrode pads 406 of the imaging substrate 402 are respectively arranged at positions facing the electrode pads 403 on the back surface of the imaging element 401. When the imaging element 401 is mounted on the imaging substrate 402, the electrode pads 403 and 406 are connected by solder (not shown), so that the imaging element 401 and the imaging substrate 402 are electrically connected. Note that the front surface of the imaging substrate 402 is an example of the first surface.

[0031] On the other hand, as shown in FIGS. 7 and 9, on the back surface of the imaging substrate 402, a region D where various electronic components 402a and connectors 407 are mounted is provided. Note that the back surface of the imaging substrate 402 is an example of the second surface which is the opposite surface of the first surface.

[0032] The region D of the imaging substrate 402 is located inside the imaging substrate 402 compared to the region C described later. In the region D, in order to suppress the warping of the imaging substrate 402, a conductor removal portion 411 in which the conductor layer of the imaging substrate 402 is partially removed is appropriately formed.

[0033] The conductor removal portion 411 is a columnar recess with a diameter D1 provided in the conductor layer Pn on the back side. As shown in FIG. 9, the surface of the conductor removal portion 411 is covered with a surface insulating layer R. By providing the conductor removal portion 411 in the conductor layer Pn, the deformation margin of the conductor layer Pn in the plane direction (XY direction) of the substrate increases by the space of the conductor removal portion 411. Thereby, the internal stress of the imaging substrate 402 accompanying the thermal expansion and contraction of the conductor layer Pn can be released, so that the imaging substrate 402 is less likely to warp. Note that the conductor removal portion 411 is an example of the first recess.

[0034] Here, if the conductor removal portion 411 is provided at the portion where the electronic component 402a is mounted, the shape of the solder applied on the cut conductor becomes non-uniform, and the difficulty of mounting the electronic component 402a increases. Therefore, in order to suppress the adverse effect on the mounting of the electronic component 402a, the conductor removal portion 411 is provided in the region D while avoiding the portions where various electronic components 402a are mounted.

[0035] Also, as shown in FIG. 7, an area C extending in a strip shape along the X direction is provided outside the area D of the imaging substrate 402 in the Y direction (the outer edge side of the substrate). The area C is an example of the first area and is the area where the imaging substrate 402 and the adhesive 405 are in contact. In the area C, a conductor removal portion 412 where the conductor layer of the imaging substrate 402 is partially removed is appropriately formed.

[0036] The conductor removal portion 412 is a columnar depression with a diameter C1 provided in the conductor layer Pn on the back side. As shown in FIG. 9, the surface of the conductor removal portion 412 is covered with a surface insulating layer R. Here, the diameter C1 of the conductor removal portion 412 is set to be larger than the diameter D1 of the conductor removal portion 411 (C1 > D1).

[0037] By increasing the diameter C1 of the conductor removal portion 412, the space of the depression formed on the substrate surface of the area C becomes larger, and the contact area with the adhesive 405 also increases. Thereby, when the adhesive 405 is applied to the area C, it becomes possible to increase the application amount of the adhesive 405 by the conductor removal portion 412. Then, since the imaging substrate 402 and the holding member 404 are more firmly adhered via the adhesive 405, for example, it is possible to prevent the adhesion between the imaging substrate 402 and the holding member 404 from decreasing even when the electronic device drops.

[0038] Also, as shown in FIG. 7, an area B having a plurality of conduction vias 413 is provided outside the area C of the imaging substrate 402 in the Y direction (the outer edge side of the substrate). The area B is an example of the second area, and the conduction via 413 is an example of the conduction portion.

[0039] As shown in FIG. 8, a plurality of conductive vias 413 in region B are arranged at regular intervals along the X direction. Also, as shown in FIG. 9, the conductive vias 413 penetrate the internal insulating layer in the imaging substrate 402 to connect the conductor layers. In the example of FIG. 9, the conductive vias 413 penetrate the internal insulating layer K3 to connect the conductor layers P3 and P4. The conductive vias 413 are columnar with a diameter of B1, and the inside is filled with a conductor by copper plating treatment in order to conduct the conductor layer P4 outside the imaging substrate 402 and the conductor layer P3 inside.

[0040] Also, as shown in FIG. 9, conductive vias 413a and conductive vias 414 are disposed in the imaging substrate 402. The conductive via 413a penetrates the internal insulating layer K1 to connect the conductor layers P1 and P2. Also, the conductive via 414 penetrates the internal insulating layer K2 to connect the conductor layers P2 and P3.

[0041] Here, the above-mentioned conductive via 413a is connected to the ground signal line GND of the imaging element 401 via the conductor layer P1 located on the mounting surface side of the imaging element 401. The ground signal of the imaging element 401 is transmitted through the conductor layer P2 of the imaging substrate 402, the conductive via 414, and the conductor layer P3, and reaches the conductor layer P4 through the conductive via 413 formed in the region B. Generally, the ground signal line GND is configured such that the cross-sectional area of the conductor is larger than that of the signal lines that transmit other signals. Therefore, the amount of heat transfer from the imaging element 401 through the ground signal line GND becomes large.

[0042] Here, it is preferable that the dimensions of the diameter B1 of the conductive via 413, the diameter C1 of the conductor removal portion 412, and the diameter D1 of the conductor removal portion 411 are set such that B1 < D1 < C1. This is because if the diameter B1 of the conductive via 413 is made larger than the diameter D1 of the conductor removal portion 411, the effect of suppressing the warping of the substrate by the conductor removal portion 411 will be reduced.

[0043] Also, as shown in FIG. 7, a region A is provided outside the region B of the imaging substrate 402 in the Y direction (the outer edge side of the substrate). Region A is the first 3An example of a region, which is configured such that heat of the imaging device 401 is transmitted through a conduction via 413 provided in an adjacent region B.

[0044] Region A is a region having a flat conductor pattern without any vias or conductor pattern cuts. By making region A flat, the contact area with a part of the holding member 404 facing region A increases. As a result, heat of the imaging substrate 402 is easily transmitted to the holding member 404, so that heat dissipation of the imaging device 401 can be efficiently performed.

[0045] Also, as shown in FIG. 9, a groove-shaped resist step R1 is formed in the surface insulating layer R between region A and region B. Similarly, a groove-shaped resist step R2 is formed in the surface insulating layer R between region C and region D. The resist steps R1 and R2 are formed, for example, by notching the surface insulating layer R in a groove shape, each having a predetermined width in the Y direction and extending along the X direction.

[0046] Here, the resist step R1 formed between region A and region B is an example of a first groove and functions as a space for an adhesive pool when the adhesive 405 protrudes from region C. By the resist step R1 functioning as an adhesive pool, it becomes difficult for the adhesive to flow between the substrate and the holding member, and a decrease in heat dissipation performance due to floating between the substrate and the holding member is suppressed. Also, the resist step R2 formed between region C and region D is an example of a second groove and functions to make it difficult for the adhesive 405 in region C to adhere to the electronic component 402a.

[0047] Also, it is preferable that the groove widths in the Y direction of the resist steps R1 and R2 are such that R1 > R2. According to the above configuration, for example, when the adhesive 405 applied to region C protrudes, the adhesive 405 is more likely to flow toward the resist step R2 with a narrower width due to capillary action. Therefore, the adhesive applied to region C is more likely to protrude in the direction of region D than in the direction of region A. Accordingly, it is further suppressed that the adhesive 405 enters between the imaging substrate 402 and the holding member 404 and the heat dissipation performance from the imaging substrate 402 to the holding member 404 deteriorates.

[0048] Even if the adhesive 405 flows into the region D, the workability of the component in the region D only decreases, so no major adverse effects will occur. Also, by reducing the groove width of the resist step R2, the area of the region D for mounting the electronic component 402a can be made wider.

[0049] In the present embodiment, as shown in FIG. 7, an example is shown in which combinations of regions A, B, and C are provided on the upper and lower sides of the imaging substrate 402, and the adhesive 405 is applied to the upper and lower sides of the imaging substrate 402. However, combinations of regions A, B, and C may be provided on the left and right sides or the upper, lower, left, and right sides of the imaging substrate 402, and the adhesive 405 may be applied.

[0050] As described above, the camera 100 of the present embodiment includes an imaging substrate 402 on which the imaging element 401 is mounted on the first surface, and a holding member 404 that is adhered to the second surface of the imaging substrate 402 and holds the imaging substrate 402. The second surface of the imaging substrate 402 includes a region A, a region B, and a region C. The holding member 404 is fixed to the region C via the adhesive 405. In the region B, conduction vias 413 that conduct the heat of the imaging element 401 from the first surface to the second surface of the imaging substrate 402 are arranged. In the region A, a part of the holding member 404 contacts the imaging substrate 402. And in the planar direction of the second surface, the region B is provided between the region C and the region A.

[0051] In the camera 100 of the present embodiment, the imaging substrate 402 and the holding member 404 are fixed with the adhesive 405 in the region A. Also, in the camera 100 of the present embodiment, a region B in which the conduction vias 413 are arranged is provided between the region C and the region A where a part of the holding member 404 contacts the imaging substrate 402. Thereby, the heat from the imaging element 401 is transmitted from the region A to the holding member 404 through the conduction vias 413 in the region B, so that the heat from the imaging element 401 can be efficiently transmitted to the holding member 404 without passing through the adhesive 405.

[0052] Next, referring to FIGS. 10 and 11, a network camera, which is another example of an electronic device, will be described. FIG. 10 is an external view of the network camera. FIG. 11 is a cross-sectional view showing an example of the internal configuration of the network camera.

[0053] The network camera 600 includes a lens unit 601 that images a subject, and a substrate 602 on which the lens unit 601 including the imaging element 604 is mounted. These elements are housed and covered by an exterior member 603. In FIG. 11, for simplicity, as an example of the substrate 602 of the network camera 600, a configuration of a two-layer substrate in which an insulating layer K1 is formed in one layer and conductor layers P1 and P2 are formed on the front and back thereof is shown.

[0054] In the network camera 600, as shown in FIG. 11, a substrate support portion 603a, which is a part of the exterior member 603, is in direct contact with the region A of the substrate 602. Other configurations related to the substrate are the same as those in the case of the camera 100 described above.

[0055] In the network camera 600 shown in FIG. 11, since the exterior member 603 functions as a holding member, miniaturization and thinning of the electronic device are facilitated as compared with the case where the exterior member and the holding member are separate components. Also, in the configuration of the network camera 600 shown in FIG. 11, heat generated by the imaging element 604 is released to the outside through the exterior member 603, so that the cooling performance of the imaging element 604 can be improved.

[0056] As described above, the preferred embodiments of the present invention have been described. However, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0057] For example, the imaging unit in the above embodiment may be a camera module mounted on a portable electronic device such as a smartphone or a portable computer terminal. Also, for example, in the above embodiment, the case where the semiconductor element mounted on the substrate is an imaging element has been described, but the semiconductor element may be other than an imaging element. As an example, the semiconductor element mounted on the substrate may be a light-emitting element such as an LED or an organic EL, an integrated circuit such as a processor, a memory, or the like.

[0058] Further, the planar shape of the conductor removal portion and the conduction via in the above embodiment is not limited to a circular shape, and may be other shapes such as a rectangular shape or an elliptical shape, for example.

Description of Reference Numerals

[0059] 100… Camera, 400… Imaging unit, 401… Imaging element, 402… Imaging substrate, 404… Holding member, 405… Adhesive, 411, 412… Conductor removal portion, 413… Conduction via, R1, R2… Resist step, A, B, C, D… Regions

Claims

1. A semiconductor element is mounted on a first surface, and a substrate in which a conductor layer and an internal insulating layer are alternately laminated, A holding member made of a metal material that is adhered to a second surface, which is the opposite surface of the first surface of the substrate, to hold the substrate, A conductor layer and a surface insulating layer covering the surface thereof are formed on the second surface of the substrate, The second surface of the substrate is, A first region to which the holding member is fixed via an adhesive, A second region in which a conduction part for guiding heat of the semiconductor element from the first surface to the second surface of the substrate is arranged, A third region in which a part of the holding member and the substrate are in direct contact, In the plane direction of the second surface, the second region is provided between the first region and the third region, The third region, the second region, and the first region are composed of the conductor layer and the surface insulating layer covering the surface thereof, and are arranged in a direction along the outer edge of the substrate, The third region is arranged on the outer edge side of the substrate rather than the adjacent second region, and the second region is arranged on the outer edge side of the substrate rather than the adjacent first region, By attaching an adhesive to the first region, the second region, and the holding member, the substrate is fixed to the holding member, and the third region is configured to directly contact the holding member without passing through the adhesive. An electronic device characterized by this.

2. The semiconductor element is an imaging element The electronic device according to claim 1.

3. The conduction part in the second region is connected to the ground signal line of the semiconductor element The electronic device according to claim 1 or 2.

4. The combination of the first region, the second region, and the third region is provided on at least two sides of the substrate The electronic device according to any one of claims 1 to 3.

5. A first groove is formed between the third region and the second region. The electronic device according to any one of claims 1 to 4.

6. A second groove is formed inside the substrate rather than the first region, The groove width of the second groove is smaller than the groove width of the first groove. The electronic device according to claim 5.

7. A first recess for suppressing warping of the substrate is formed in a region located inside the substrate rather than the first region, The dimension of the first recess in the planar direction is larger than the dimension of the conduction part in the planar direction. The electronic device according to any one of claims 1 to 6.

8. A second recess for increasing the contact area with the adhesive is formed on the surface of the first region, The dimension of the second recess in the planar direction is larger than the dimension of the first recess in the planar direction. The electronic device according to claim 7.

Images