Semiconductor storage device

Abstract

To provide a semiconductor storage device capable of reducing the number of components.SOLUTION: A semiconductor storage device of one embodiment comprises a housing, a substrate, and a semiconductor memory. The housing includes a first member and a second member. The first member includes an engagement part and a first fixing part. The engagement part is arranged inside the housing, and includes a first portion extending in a thickness direction of the substrate and a second portion extending in a first direction along a first surface from the first portion. The first fixing part is mounted with a fastening member. The second member includes a receiving part and a second fixing part. The receiving part includes an insertion space opened in a second direction opposite to the first direction, and engages with the engagement part when the second member moves in the second direction with respect to the first member, causing the second portion to be inserted into the insertion space. The second fixing part is fixed to the first fixing part by the fastening member with the engagement part and the receiving part engaged with each other.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a semiconductor memory device.

Background Art

[0002] A semiconductor memory device having a housing, a substrate disposed within the housing, and a semiconductor memory provided on the substrate is known.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] One embodiment provides a semiconductor memory device capable of reducing the number of components.

Means for Solving the Problems

[0005] A semiconductor memory device according to an embodiment includes a housing, a substrate, and a semiconductor memory. The housing has an accommodation space. The substrate is disposed in the accommodation space and has a first surface. The semiconductor memory is provided on the first surface. The housing includes a first member and a second member combined with the first member. The accommodation space is formed between the first member and the second member. The first member has an engaging portion and a first fixing portion. The engaging portion is disposed inside the housing and includes a first portion extending in the thickness direction of the substrate and a second portion extending in a first direction along the first surface from the first portion. The first fixing portion is where a fastening member is attached. The second member has a receiving portion and a second fixing portion. The receiving portion includes an insertion space opened in a second direction opposite to the first direction, and when the second member is moved in the second direction with respect to the first member, the second portion is inserted into the insertion space and engages with the engaging portion. The second fixing portion is fixed to the first fixing portion by the fastening member in a state where the engaging portion and the receiving portion are engaged.

Brief Description of the Drawings

[0006]

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Embodiments for Carrying Out the Invention

[0007] Hereinafter, the semiconductor memory device of the embodiment will be described with reference to the drawings. In the following description, components having the same or similar functions are denoted by the same reference numerals. And the overlapping descriptions of those components may be omitted. In the present application, "parallel", "orthogonal", or "the same" may each include the case of being "substantially parallel", "substantially orthogonal", or "substantially the same". In the present application, "connection" is not limited to mechanical connection and may include electrical connection. That is, "connection" is not limited to the case of being directly connected to an object and may include the case of being connected to an object with another member interposed therebetween.

[0008] In this application, the +X direction, -X direction, +Y direction, -Y direction, +Z direction, and -Z direction are defined as follows. The +X direction, -X direction, +Y direction, and -Y direction are directions parallel to the first surface 21a (see FIG. 2) of the substrate 21 described later. The +X direction is the direction from the first end portion 10a to the second end portion 10b of the housing 10 described later (see FIG. 1). The -X direction is the direction opposite to the +X direction. When the +X direction and the -X direction are not distinguished, they are simply referred to as the "X direction". The +Y direction and the -Y direction are directions that intersect (for example, are orthogonal to) the X direction. The +Y direction is the direction from the third end portion 10c to the fourth end portion 10d of the housing 10 described later (see FIG. 1). The -Y direction is the direction opposite to the +Y direction. When the +Y direction and the -Y direction are not distinguished, they are simply referred to as the "Y direction".

[0009] The +Z direction and the -Z direction are directions that intersect (for example, are orthogonal to) the X direction and the Y direction, and are the thickness direction of the substrate 21. The +Z direction is the direction from the first main wall 11 to the second main wall 12 of the housing 10 (see FIG. 1). The -Z direction is the direction opposite to the +Z direction. When the +Z direction and the -Z direction are not distinguished, they are simply referred to as the "Z direction". Hereinafter, the -Z direction side may be referred to as "down" and the +Z direction side may be referred to as "up". However, these expressions are for convenience of explanation and do not define the direction of gravity. The -X direction is an example of the "first direction". The +X direction is an example of the "second direction". The Y direction is an example of the "third direction".

[0010] (First Embodiment) <1. Overall Configuration of Semiconductor Memory Device> Referring to FIGS. 1 to 12, the semiconductor memory device 1 of the first embodiment will be described. The semiconductor memory device 1 is a storage device such as an SSD (Solid State Drive), for example. The semiconductor memory device 1 is connected to a host device and used as a storage device of the host device. The host device is a personal computer, a mobile device, a video recorder, an in-vehicle device, or the like, but is not limited to these examples.

[0011] FIG. 1 is a perspective view showing a semiconductor memory device 1. The semiconductor memory device 1 has, for example, a housing 10 and a substrate unit 20 (see FIG. 2).

[0012] <1.1 Housing> The housing 10 is a member that forms the outer shell of the semiconductor memory device 1. The housing 10 is, for example, in the shape of a flat box. The housing 10 has a first end 10a, a second end 10b, a third end 10c, and a fourth end 10d. The first end 10a and the second end 10b are a pair of ends divided in the longitudinal direction (X direction) of the housing 10. The third end 10c and the fourth end 10d are a pair of ends divided in the short-side direction (Y direction) of the housing 10.

[0013] The housing 10 has a first main wall 11, a second main wall 12, and a peripheral wall 13. The first main wall 11, the second main wall 12, and the peripheral wall 13 are wall portions that are exposed to the outside of the housing 10 and define the outer shape of the housing 10.

[0014] (First Main Wall) The first main wall 11 is a wall portion facing the substrate unit 20 from the -Z direction side. The first main wall 11 is curved so as to be recessed toward the inside of the housing 10, for example, for improving design, improving rigidity, or for another purpose (see FIG. 10). Note that the first main wall 11 may be a flat wall along the X direction and the Y direction.

[0015] (Second Main Wall) The second main wall 12 is a wall portion facing the substrate unit 20 from the +Z direction side. The second main wall 12 is curved so as to be recessed toward the inside of the housing 10, for example, for improving design, improving rigidity, or for another purpose (see FIG. 10). Note that the second main wall 12 may be a flat wall along the X direction and the Y direction.

[0016] (Peripheral Wall) The peripheral wall 13 is an annular wall portion surrounding the periphery of the substrate unit 20. The peripheral wall 13 extends in the Z direction and connects the peripheral ends of the first main wall 11 and the second main wall 12. The peripheral wall 13 includes, for example, first and second end walls 13a, 13b, first and second side walls 13c, 13d, and first to fourth curved walls 13e, 13f, 13g, 13h.

[0017] The first end wall 13a is located at the first end portion 10a of the housing 10. The first end wall 13a is located on the -X direction side with respect to the substrate unit 20. The first end wall 13a is, for example, a flat wall along the Y direction and the Z direction. The first end wall 13a has an opening 10h. The opening 10h penetrates the first end wall 13a in the Y direction. The opening 10h exposes the connection connector 22 of the substrate unit 20, which will be described later, to the outside of the housing 10. The second end wall 13b is located at the second end portion 10b of the housing 10. The second end wall 13b is located on the +X direction side with respect to the substrate unit 20. The second end wall 13b is, for example, a flat wall along the Y direction and the Z direction.

[0018] The first side wall 13c is located at the third end portion 10c of the housing 10. The first side wall 13c is located on the -Y direction side with respect to the substrate unit 20. The first side wall 13c is, for example, a flat wall along the X direction and the Z direction. The second side wall 13d is located at the fourth end portion 10d of the housing 10. The second side wall 13d is located on the +Y direction side with respect to the substrate unit 20. The second side wall 13d is, for example, a flat wall along the X direction and the Z direction.

[0019] Each of the first curved wall 13e, the second curved wall 13f, the third curved wall 13g, and the fourth curved wall 13h is an arcuate wall portion that protrudes outwardly of the housing 10. The first curved wall 13e is located between the first end wall 13a and the first side wall 13c and connects the first end wall 13a and the first side wall 13c. The second curved wall 13f is located between the first end wall 13a and the second side wall 13d and connects the first end wall 13a and the second side wall 13d. The third curved wall 13g is located between the second end wall 13b and the first side wall 13c and connects the second end wall 13b and the first side wall 13c. The fourth curved wall 13h is located between the second end wall 13b and the second side wall 13d and connects the second end wall 13b and the second side wall 13d.

[0020] FIG. 2 is a perspective view showing a partial decomposition of the semiconductor memory device 1. The housing 10 has, for example, a base 30 and a cover 60. In the present embodiment, the housing 10 is formed by combining the base 30 and the cover 60. When the base 30 and the cover 60 are combined, an accommodation space S, which is the internal space of the housing 10, is formed between the base 30 and the cover 60. Details of the base 30 and the cover 60 will be described later. The base 30 is an example of the "first member". The cover 60 is an example of the "second member".

[0021] <1.2 Substrate Unit> Next, the substrate unit 20 will be described. The substrate unit 20 is disposed in the accommodation space S of the housing 10. The substrate unit 20 has, for example, a substrate 21, a connection connector 22, a controller 23, and a plurality of NAND type flash memories 24 (hereinafter referred to as "NAND 24").

[0022] The substrate 21 is a plate member along the X direction and the Y direction. The substrate 21 is a printed circuit board and includes an insulating base material and a wiring pattern provided on the insulating base material. The substrate 21 has a first surface 21a and a second surface 21b located on the side opposite to the first surface 21a. The first surface 21a extends in the X direction and the Y direction. The first surface 21a faces the -Z direction. The second surface 21b extends in the X direction and the Y direction. The second surface 21b faces the +Z direction.

[0023] The connection connector 22 is a connection part connectable to the connector of the host device. The connection connector 22 includes a plurality of metal terminals connectable to the connector of the host device. The connection connector 22 is provided, for example, on the second surface 21b of the substrate 21. The connection connector 22 is exposed to the outside of the housing 10 through the opening 10h of the housing 10 (see FIG. 1).

[0024] The controller 23 is a component that comprehensively controls the entire semiconductor memory device 1. The controller 23 is, for example, a semiconductor package including a SoC (System on a Chip) in which a host interface circuit for a host device and a control circuit for controlling a plurality of NANDs 24 are integrated on one semiconductor chip. The controller 23 is provided, for example, on the second surface 21b of the substrate 21.

[0025] The controller 23 may include a DRAM (Dynamic Random Access Memory). The DRAM is a data buffer in which write target data received from a host device, read target data read from the NAND 24, etc. are temporarily stored. Note that the DRAM may be provided on the substrate 21 as a separate component instead of being provided inside the controller 23.

[0026] The NAND 24 is a semiconductor package including non-volatile semiconductor memory chips. The NAND 24 is provided, for example, on the first surface 21a and the second surface 21b of the substrate 21. The plurality of NANDs 24 are arranged side by side in the X direction. The NAND 24 is an example of a "semiconductor memory". Note that the "semiconductor memory" referred to in this application is not limited to the NAND 24, and may be other types of semiconductor memories such as NOR type memories, MRAM (Magnetoresistive Random Access Memory), or resistive change type memories.

[0027] <2. Base structure> Next, the structure of the base 30 will be described. FIG. 3 is a perspective view showing the base 30. The base 30 has, for example, a first main wall 11, a peripheral wall 33, an engaging portion 34, a substrate support portion 35, and a fixing portion 36. Since the first main wall 11 has been described above, redundant description here is omitted.

[0028] In this embodiment, the base 30 is a single-piece metal part P1 integrally formed by die casting. For example, the first main wall 11, the peripheral wall 33, the engaging portion 34, the substrate support portion 35, and the fixing portion 36 are integrally formed as a single-piece metal part P1. The metal part P1 is an example of the "first part". The base 30 is formed, for example, by aluminum die casting, but may also be formed by die casting using another metal material.

[0029] <2.1 Peripheral Wall> First, the peripheral wall 33 will be described. The peripheral wall 33 is a wall portion that forms a part of the peripheral wall 13 of the housing 10 described above. The peripheral wall 33 includes, for example, the first and second end walls 33a, 33b, the first and second side walls 33c, 33d, and the first to fourth curved walls 33e, 33f, 33g, 33h. The Z-direction height H1 of the end walls 33a, 33b, the side walls 33c, 33d, and the curved walls 33e, 33f, 33g, 33h is, for example, the same as each other.

[0030] (First End Wall) The first end wall 33a is an upright wall extending in the +Z direction from the -X-direction end of the first main wall 11. The first end wall 33a is, for example, a flat wall along the Y direction and the Z direction. The first end wall 33a forms a part of the first end wall 13a of the housing 10 described above. The first end wall 33a has, for example, the lower half 10ha of the opening 10h.

[0031] (Second End Wall) The second end wall 33b is an upright wall extending in the +Z direction from the +X-direction end of the first main wall 11. The second end wall 33b is, for example, a flat wall along the Y direction and the Z direction. The second end wall 33b forms a part of the second end wall 13b of the housing 10 described above.

[0032] (First Side Wall) The first side wall 33c is an upright wall extending in the +Z direction from the end portion on the -Y direction side of the first main wall 11. The first side wall 33c is, for example, a flat wall along the X direction and the Z direction. The first side wall 33c forms a part of the first side wall 13c of the housing 10 described above. In the present embodiment, the thickness T33c of the first side wall 33c in the Y direction is larger than the thickness T33a of the first end wall 33a in the X direction. From another perspective, the thickness T33c of the first side wall 33c in the Y direction is larger than the thickness T21 of the substrate 21 in the Z direction (see FIG. 2).

[0033] In the present embodiment, the first side wall 33c has a guide surface 39A exposed to the accommodation space S. The guide surface 39A is a plane along the X direction and the Z direction. The guide surface 39A guides the slide movement in the X direction of the first receiving portion 64A of the cover 60 described later.

[0034] (The second side wall) The second side wall 33d is an upright wall extending in the +Z direction from the end portion on the +Y direction side of the first main wall 11. The second side wall 33d is, for example, a flat wall along the X direction and the Z direction. The second side wall 33d forms a part of the second side wall 13d of the housing 10 described above. In the present embodiment, the thickness T33d of the second side wall 33d in the Y direction is larger than the thickness T33a of the first end wall 33a in the X direction. From another perspective, the thickness T33d of the second side wall 33d in the Y direction is larger than the thickness T21 of the substrate 21 in the Z direction (see FIG. 2).

[0035] In the present embodiment, the second side wall 33d has a guide surface 39B exposed to the accommodation space S. The guide surface 39B is a plane along the X direction and the Z direction. The guide surface 39B guides the slide movement in the X direction of the second receiving portion 64B of the cover 60 described later.

[0036] (The first to fourth curved walls) Each of the first curved wall 33e, the second curved wall 33f, the third curved wall 33g, and the fourth curved wall 33h is an upright wall extending in the +Z direction from the end portion of the first main wall 11. Each of the first curved wall 33e, the second curved wall 33f, the third curved wall 33g, and the fourth curved wall 33h is an arcuate wall portion convex toward the outside of the housing 10.

[0037] The first curved wall 33e is located between the first end wall 33a and the first side wall 33c, and connects the first end wall 33a and the first side wall 33c. The first curved wall 33e forms a part of the first curved wall 13e of the housing 10 described above. The second curved wall 33f is located between the first end wall 33a and the second side wall 33d, and connects the first end wall 33a and the second side wall 33d. The second curved wall 33f forms a part of the second curved wall 13f of the housing 10 described above.

[0038] The third curved wall 33g is located between the second end wall 33b and the first side wall 33c, and connects the second end wall 33b and the first side wall 33c. The third curved wall 33g forms a part of the third curved wall 13g of the housing 10 described above. The fourth curved wall 33h is located between the second end wall 33b and the second side wall 33d, and connects the second end wall 33b and the second side wall 33d. The fourth curved wall 33h forms a part of the fourth curved wall 13h of the housing 10 described above.

[0039] <2.2 Engagement portion> Next, the engagement portion 34 will be described. The engagement portion 34 is a portion that engages with a receiving portion 64 of a cover 60 described later. The engagement portion 34 is disposed inside the housing 10. For example, the engagement portion 34 is provided on the first main wall 11 and protrudes from the first main wall 11 into the accommodation space S. Note that in the present application, the phrase "disposed inside the housing" is not limited to the case where it is disposed away from the peripheral wall 13 of the housing 10 (for example, the peripheral wall 33 of the base 30), and may also include the case where it is integrally formed with the inner surface of the peripheral wall 13 of the housing 10 (for example, the peripheral wall 33 of the base 30).

[0040] (Arrangement position of the engagement portion) In the present embodiment, the engagement portion 34 includes a plurality of engagement portions 34A, 34B (the first engagement portion 34A and the second engagement portion 34B). The plurality of engagement portions 34A, 34B are, for example, offset in the -X direction side with respect to the center C1 in the X direction of the first main wall 11.

[0041] FIG. 4 is a diagram showing the base 30. (a) in FIG. 4 shows the base 30 viewed from the +Z direction side. (b) in FIG. 4 shows the base 30 viewed from the -Y direction side. (c) in FIG. 4 shows the base 30 viewed from the +X direction side. (d) in FIG. 4 shows the base 30 viewed from the -X direction side. In the present embodiment, the first engaging portion 34A is arranged apart from the first side wall 33c and the second side wall 33d. The first engaging portion 34A is arranged between the substrate 21 and the first side wall 33c when viewed from the Z direction. A first gap g1 is provided between the first engaging portion 34A and the first side wall 33c.

[0042] In the present embodiment, the first engaging portion 34A is arranged along the end portion of the substrate 21 on the -Y direction side. A second gap g2 may exist between the first engaging portion 34A and the substrate 21. The width of the second gap g2 in the Y direction is substantially zero or smaller than the width of the first gap g1 in the Y direction. The substrate 21 can be aligned in the Y direction using, for example, the side surface 34Aa on the +Y direction side of the first engaging portion 34A as a guide.

[0043] Similarly, the second engaging portion 34B is arranged apart from the first side wall 33c and the second side wall 33d. The second engaging portion 34B is arranged between the substrate 21 and the second side wall 33d when viewed from the Z direction. A third gap g3 is provided between the second engaging portion 34B and the second side wall 33d.

[0044] In the present embodiment, the second engaging portion 34B is arranged along the end portion of the substrate 21 on the +Y direction side. A gap between the second engaging portion 34B and the substrate 21 may be the fourth gap g4. The width of the fourth gap g4 in the Y direction is substantially zero or smaller than the width of the third gap g3 in the Y direction. The substrate 21 can be aligned using, for example, the side surface 34Ba on the -Y direction side of the second engaging portion 34B as a guide.

[0045] (Shape of the engaging portion) In this embodiment, the plurality of engaging portions 34A and 34B have the same shape as each other. Therefore, hereinafter, the shape of the first engaging portion 34A will be described as a representative. The shape of the second engaging portion 34B may be read as "the upper end surface 33de of the second side wall 33d" instead of "the upper end surface 33ce of the first side wall 33c" in the description of the first engaging portion 34A described below.

[0046] FIG. 5 is a perspective view showing an enlarged view of the region surrounded by the dashed-dotted line F5 shown in FIG. 3. The engaging portion 34A has, for example, a base portion 41 and a protruding portion 42. The base portion 41 is an example of the "first portion". The protruding portion 42 is an example of the "second portion".

[0047] The base portion 41 extends in the +Z direction from the first main wall 11. The base portion 41 is a plate portion along the X direction and the Y direction. In this embodiment, the base portion 41 extends to the +Z direction side beyond the upper end surface 33ce of the first side wall 33c (the boundary portion B between the base 30 and the cover 60) (see FIG. 10).

[0048] The protruding portion 42 protrudes in the -X direction from the end portion on the +Z direction side of the base portion 41. A space SG is provided between the protruding portion 42 and the first main wall 11. In this embodiment, at least a part of the protruding portion 42 is disposed closer to the second main wall 12 of the cover 60 than the upper end surface 33ce of the first side wall 33c (the boundary portion B between the base 30 and the cover 60). The shortest distance between at least a part of the protruding portion 42 and the second main wall 12 is smaller than the shortest distance between the upper end surface 33ce of the first side wall 33c (the boundary portion B between the base 30 and the cover 60) and the second main wall 12.

[0049] In this embodiment, the protruding portion 42 extends in the -X direction from the end portion on the +Z direction side of the base portion 41 at a position away from the first side wall 33c and the second side wall 33d. The width W42 of the protruding portion 42 in the Y direction is the same as the width W41 of the base portion 41 in the Y direction. The lower surface of the protruding portion 42 has a first contact portion CF1 that contacts the receiving portion 64 of the cover 60 described later. In this embodiment, the first contact portion CF1 is a contact surface provided as a part of the lower surface of the protruding portion 42. The first contact portion CF1 is, for example, a plane along the X direction and the Y direction.

[0050] <2.3 Substrate support part> Returning to FIG. 2, the substrate support part 35 will be described. The substrate support part 35 is a support part that supports the substrate 21 within the housing 10. The substrate support part 35 has, for example, first to third support parts 51, 52, 53 to which screw members 45 are respectively attached, and fourth to ninth support parts 54, 55, 56, 57, 58, 59 to which the screw members 45 are not attached.

[0051] (First support part) The first support part 51 is a protruding part that protrudes in the +Z direction from the first main wall 11. The first support part 51 is arranged at a position overlapping a part of the end on the +X direction side of the substrate 21 when viewed in the Z direction. The first support part 51 has, for example, a mounting surface 50a, an engagement hole 50b, and a position regulating part 50c.

[0052] The mounting surface 50a is a plane along the X direction and the Y direction. The first surface 21a of the substrate 21 is mounted on the mounting surface 50a.

[0053] The engagement hole 50b opens to the mounting surface 50a. The engagement hole 50b extends in the Z direction inside the first support part 51. The inner peripheral surface of the engagement hole 50b has, for example, an internal thread. In the engagement hole 50b, for example, the screw member 45 is engaged with a washer 46 interposed therebetween. The screw member 45 presses the substrate 21 toward the mounting surface 50a via the washer 46.

[0054] The position regulating part 50c is located on the +X direction side of the mounting surface 50a. The position regulating part 50c protrudes in the +Z direction more than the mounting surface 50a. The position regulating part 50c is formed in an arc shape so as to avoid the engagement hole 50b, for example. The position regulating part 50c faces the substrate 21 placed on the mounting surface 50a from the +X direction side. The position regulating part 50c regulates the position of the substrate 21 in the +X direction.

[0055] (Second support part) The second support portion 52 is a protruding portion that protrudes from the first main wall 11 in the +Z direction. The second support portion 52 is disposed at a position overlapping a part of the end portion on the -Y direction side of the substrate 21 when viewed from the Z direction. The second support portion 52 includes a placement surface 50a, an engagement hole 50b, and a position regulating portion 50c, similar to the first support portion 51. For details of the second support portion 52, in the description of the first support portion 51 described above, “+X direction” may be read as “-Y direction”.

[0056] (The third support portion) The third support portion 53 is a protruding portion that protrudes from the first main wall 11 in the +Z direction. The third support portion 53 is disposed at a position overlapping a part of the end portion on the +Y direction side of the substrate 21 when viewed from the Z direction. The third support portion 53 includes a placement surface 50a, an engagement hole 50b, and a position regulating portion 50c, similar to the first support portion 51. For details of the third support portion 53, in the description of the first support portion 51 described above, “+X direction” may be read as “+Y direction”.

[0057] (The fourth to ninth support portions) The fourth to ninth support portions 54, 55, 56, 57, 58, 59 are protruding portions that protrude from the first main wall 11 in the +Z direction. The fourth to sixth support portions 54, 55, 56 are disposed at positions overlapping the end portions on the -Y direction side of the substrate 21 when viewed from the Z direction. The fourth to sixth support portions 54, 55, 56 are arranged separately in the X direction. The fourth to sixth support portions 54, 55, 56 are in contact with the first surface 21a of the substrate 21 from the -Z direction side and support the substrate 21. The seventh to ninth support portions 57, 58, 59 are disposed at positions overlapping the end portions on the +Y direction side of the substrate 21 when viewed from the Z direction. The seventh to ninth support portions 57, 58, 59 are arranged separately in the X direction. The seventh to ninth support portions 57, 58, 59 are in contact with the first surface 21a of the substrate 21 from the -Z direction side and support the substrate 21.

[0058] <2.4 Fixing portion> The fixing portion 36 is a portion fixed to the fixing portion 66 of the cover 60 by a fastening member 90 described later. The fixing portion 36 is an example of a "first fixing portion". In the present embodiment, the fixing portion 36 is provided at the second end portion 10b of the housing 10. For example, the fixing portion 36 is provided on the second end wall 33b of the base 30 and is exposed to the outside of the housing 10. The fixing portion 36 has an insertion hole 36h through which the fastening member 90 is inserted. The insertion hole 36h penetrates the fixing portion 36 in the X direction. The fastening member 90 is attached to the fixing portion 36. Note that in the present application, "the fastening member is attached" is not limited to the case where the fastening member is fixed, but also includes the case where the fastening member is inserted into the insertion hole.

[0059] <3. Structure of the Cover> Next, the structure of the cover 60 will be described. FIG. 6 is a perspective view showing the cover 60. The cover 60 has, for example, a second main wall 12, a peripheral wall 63, a receiving portion 64, a substrate support portion 65, and a fixing portion 66. Since the second main wall 12 has been described above, the overlapping description here will be omitted.

[0060] In the present embodiment, the cover 60 is a single-piece metal part P2 integrally formed by die casting. For example, the second main wall 12, the peripheral wall 63, the receiving portion 64, the substrate support portion 65, and the fixing portion 66 are integrally formed as one metal part P2. The metal part P2 is an example of a "second part". The cover 60 is formed by, for example, aluminum die casting, but may be formed by die casting using another metal material.

[0061] <2.1 Peripheral Wall> First, the peripheral wall 63 will be described. The peripheral wall 63 is a wall portion that forms a part of the peripheral wall 13 of the housing 10 described above. The peripheral wall 63 includes, for example, the third and fourth end walls 63a, 63b, the third and fourth side walls 63c, 63d, and the fifth to eighth curved walls 63e, 63f, 63g, 63h. In the present embodiment, the Z-direction heights H2 of the end walls 63a, 63b, the side walls 63c, 63d, and the curved walls 63e, 63f, 63g, 63h are the same as each other. In the present embodiment, the height H2 of the peripheral wall 63 of the cover 60 is smaller than the height H1 (see FIG. 3) of the peripheral wall 33 of the base 30.

[0062] (Third end wall) The third end wall 63a is an upright wall extending in the -Z direction from the end portion on the -X direction side of the second main wall 12. The third end wall 63a is, for example, a flat wall along the Y direction and the Z direction. The third end wall 63a forms a part of the first end wall 13a of the housing 10 described above. In the present embodiment, the lower end surface 63ae of the third end wall 63a is in contact with the upper end surface 33ae (see FIG. 3) of the first end wall 33a of the base 30. For example, the lower end surface 63ae of the third end wall 63a is placed on the upper end surface 33ae of the first end wall 33a of the base 30. The lower end surface 63ae and the upper end surface 33ae are planes along the X direction and the Y direction, respectively. The third end wall 63a has, for example, the upper half 10hb of the opening 10h. In the present embodiment, the first end wall 13a of the housing 10 is formed by the third end wall 63a of the cover 60 and the first end wall 33a of the base 30.

[0063] (Fourth end wall) The fourth end wall 63b is an upright wall extending in the -Z direction from the end of the second main wall 12 on the +X direction side. The fourth end wall 63b is, for example, a flat wall along the Y direction and the Z direction. The fourth end wall 63b forms a part of the second end wall 13b of the housing 10 described above. In the present embodiment, the lower end surface 63be of the fourth end wall 63b is in contact with the upper end surface 33be (see FIG. 3) of the second end wall 33b of the base 30. For example, the lower end surface 63be of the fourth end wall 63b is placed on the upper end surface 33be of the second end wall 33b of the base 30. The lower end surface 63be and the upper end surface 33be are planes along the X direction and the Y direction, respectively. In the present embodiment, the second end wall 13b of the housing 10 is formed by the fourth end wall 63b of the cover 60 and the second end wall 33b of the base 30.

[0064] (The third side wall) The third side wall 63c is an upright wall extending in the -Z direction from the end of the second main wall 12 on the -Y direction side. The third side wall 63c is, for example, a flat wall along the Y direction and the Z direction. The third side wall 63c forms a part of the first side wall 13c of the housing 10 described above. In the present embodiment, the lower end surface 63ce of the third side wall 63c is in contact with the upper end surface 33ce (see FIG. 3) of the first side wall 33c of the base 30. For example, the lower end surface 63ce of the third side wall 63c is placed on the upper end surface 33ce of the first side wall 33c of the base 30 (see FIG. 3). The lower end surface 63ce and the upper end surface 33ce are planes along the X direction and the Y direction, respectively. In the present embodiment, the first side wall 13c of the housing 10 is formed by the third side wall 63c of the cover 60 and the first side wall 33c of the base 30. In the present embodiment, the thickness T63c of the third side wall 63c in the Y direction is larger than the thickness T63a of the third end wall 63a in the X direction. From another perspective, the thickness T63c of the third side wall 63c in the Y direction is larger than the thickness T21 of the substrate 21 in the Z direction (see FIG. 2).

[0065] (The fourth side wall) The fourth side wall 63d is an upright wall extending in the +Z direction from the end of the first main wall 11 on the +Y direction side. The fourth side wall 63d is, for example, a flat wall along the Y direction and the Z direction. The fourth side wall 63d forms a part of the second side wall 13d of the housing 10 described above. In the present embodiment, the lower end surface 63de of the fourth side wall 63d is in contact with the upper end surface 33de (see FIG. 3) of the second side wall 33d of the base 30. For example, the lower end surface 63de of the fourth side wall 63d is placed on the upper end surface 33de of the second side wall 33d of the base 30. The lower end surface 63de and the upper end surface 33de are planes along the X direction and the Y direction, respectively. In the present embodiment, the second side wall 13d of the housing 10 is formed by the fourth side wall 63d of the cover 60 and the second side wall 33d of the base 30. In the present embodiment, the thickness T64d of the fourth side wall 64d in the Y direction is larger than the thickness T63a of the third end wall 63a in the X direction. From another perspective, the thickness T63d of the fourth side wall 63d in the Y direction is larger than the thickness T21 of the substrate 21 in the Z direction (see FIG. 2).

[0066] (The fifth to eighth curved walls) Each of the fifth curved wall 63e, the sixth curved wall 63f, the seventh curved wall 63g, and the eighth curved wall 63h is an upright wall extending in the -Z direction from the end of the second main wall 12. Each of the fifth curved wall 63e, the sixth curved wall 63f, the seventh curved wall 63g, and the eighth curved wall 63h is an arcuate wall portion that bulges outward from the housing 10.

[0067] The fifth curved wall 63e is located between the third end wall 63a and the third side wall 63c and connects the third end wall 63a and the third side wall 63c. The fifth curved wall 63e forms a part of the first curved wall 13e of the housing 10 described above. In the present embodiment, the first curved wall 13e of the housing 10 is formed by the fifth curved wall 63e of the cover 60 and the first curved wall 33e of the base 30.

[0068] The sixth curved wall 63f is located between the third end wall 63a and the fourth side wall 63d and connects the third end wall 63a and the fourth side wall 63d. The sixth curved wall 63f forms a part of the second curved wall 13f of the housing 10 described above. In the present embodiment, the second curved wall 13f of the housing 10 is formed by the sixth curved wall 63f of the cover 60 and the second curved wall 33f of the base 30.

[0069] The seventh curved wall 63g is located between the fourth end wall 63b and the third side wall 63c and connects the fourth end wall 63b and the third side wall 63c. The seventh curved wall 63g forms part of the third curved wall 13g of the housing 10 described above. In the present embodiment, the third curved wall 13g of the housing 10 is formed by the seventh curved wall 63g of the cover 60 and the third curved wall 33g of the base 30.

[0070] The eighth curved wall 63h is located between the fourth end wall 63b and the fourth side wall 63d and connects the fourth end wall 63b and the fourth side wall 63d. The eighth curved wall 63h forms part of the fourth curved wall 13h of the housing 10 described above. In the present embodiment, the fourth curved wall 13h of the housing 10 is formed by the eighth curved wall 63h of the cover 60 and the fourth curved wall 33h of the base 30.

[0071] <3.2 Receiving portion> Next, the receiving portion 64 will be described. The receiving portion 64 is a portion that engages with the engaging portion 34 of the base 30. The receiving portion 64 is provided on the second main wall 12 and protrudes from the second main wall 12 into the interior of the housing 10. The receiving portion 64 is disposed in the accommodation space S of the housing 10.

[0072] (Arrangement position of the receiving portion) In the present embodiment, the receiving portion 64 includes a plurality of receiving portions 64A, 64B (the first receiving portion 64A and the second receiving portion 64B). The plurality of receiving portions 64A, 64B are, for example, offset in the -X direction side with respect to the center C2 in the X direction of the second main wall 12.

[0073] FIG. 7 is a view showing the cover 60. (a) in FIG. 7 shows the cover 60 viewed from the -Z direction side. (b) in FIG. 7 shows the cover 60 viewed from the +Y direction side. (c) in FIG. 7 shows the cover 60 viewed from the +X direction side. (d) in FIG. 7 shows the cover 60 viewed from the -X direction side. In the present embodiment, when viewed in the Z direction, the first receiving portion 64A is disposed between the substrate 21 and the third side wall 63c. The first receiving portion 64A is, for example, adjacent to the third side wall 63c in the Y direction and is connected to the inner surface of the third side wall 63c. The second receiving portion 64B is disposed between the substrate 21 and the fourth side wall 63d when viewed in the Z direction. The second receiving portion 64B is, for example, adjacent to the fourth side wall 63d in the Y direction and is connected to the inner surface of the fourth side wall 63d.

[0074] (Shape of the engaging portion) In the present embodiment, the plurality of receiving portions 64A and 64B have a shape that is symmetric about a virtual line L extending in the X direction with the center C2 of the second main wall 12 as the center line. Therefore, hereinafter, the shape of the first receiving portion 64A will be described as a representative. The shape of the second receiving portion 64B may be obtained by reading " -Y direction" as " +Y direction", " +Y direction" as " -Y direction", "the first engaging portion 34A" as "the second engaging portion 34B", "the third side wall 63c" as "the fourth side wall 63d", "the lower end surface 63ce of the third side wall 63c" as "the lower end surface 64ce of the fourth side wall 64c", "the first gap g1" as "the third gap g3", "the first guiding surface 39A" as "the second guiding surface 39B", and "the first guiding portion 79A" as "the second guiding portion 79B" in the description of the first receiving portion 64A described below.

[0075] FIG. 8 is a perspective view showing an enlarged view of the region surrounded by the one-dot chain line F8 shown in FIG. 6. The first receiving portion 64A has, for example, a first base portion 71, a second base portion 72, an extending portion 73, and an insertion space SI. The insertion space SI is a space portion defined by the first base portion 71, the second base portion 72, the extending portion 73, and the second main wall 12. The first base portion 71 is an example of the "third portion". The extending portion 73 is an example of the "fourth portion".

[0076] (The first base portion) FIG. 9 is a cross-sectional view taken along line F9-F9 of the semiconductor memory device 1 shown in FIG. 1. For convenience of explanation, illustration of the substrate unit 20 is omitted in FIG. 9. The first base portion 71 extends in the -Z direction from the second main wall 12. At least a part of the first base portion 71 is adjacent to the third side wall 63c in the Y direction and is connected to the third side wall 63c in the Y direction. In the present embodiment, the first base portion 71 extends to the -Z direction side beyond the lower end surface 63ce (boundary portion B between the base 30 and the cover 60) of the third side wall 63c. The first base portion 71 is a plate portion along the X direction and the Y direction. The width W71 (for example, the maximum width) of the first base portion 71 in the Y direction is, for example, equal to or greater than the thickness W63c of the third side wall 63c in the Y direction. The first base portion 71 supports the extension portion 73 from the -Y direction side.

[0077] In the present embodiment, at least a part of the first base portion 71 is inserted into the first gap g1 between the first engaging portion 34A and the first side wall 33c. The first base portion 71 has a guide portion 79A along the inner surface of the first side wall 33c. The guide portion 79A, for example, follows the guide surface 39A of the first side wall 33c. In the process of combining the base 30 and the cover 60, the guide portion 79A is guided by the guide surface 39A of the first side wall 33c and is slid in the +X direction.

[0078] (Second base portion) FIG. 10 is a cross-sectional view taken along line F10-F10 of the semiconductor memory device 1 shown in FIG. 1. For convenience of explanation, illustration of the controller 23 and the NAND 24 on the substrate 21 is omitted in FIG. 10. The second base portion 72 extends in the -Z direction from the second main wall 12. In the present embodiment, the second base portion 72 extends to the -Z direction side beyond the lower end surface 63ce (boundary portion B between the base 30 and the cover 60) of the third side wall 63c. The second base portion 72 supports the extension portion 73 from the -X direction side.

[0079] (Extension portion) The extension portion 73 extends in the +Y direction from the end portion on the -Z direction side of the first base portion 71 (see FIG. 9). From another perspective, the extension portion 73 extends in the +X direction from the end portion on the -Z direction side of the second base portion 72. At least a part of the extension portion 73 is located on the -Z direction side of, for example, the lower end surface 63ce of the third side wall 63c (the boundary portion B between the base 30 and the cover 60). The extension portion 73 is located away from the second main wall 12. An insertion space SI is defined by the upper surface of the extension portion 73 and the lower surface of the second main wall 12 between the extension portion 73 and the second main wall 12.

[0080] The -Y direction side of the insertion space SI is blocked by the first base portion 71 (see FIG. 9). On the other hand, the +Y direction side of the insertion space SI is open to the inside of the housing 10 (see FIG. 9). The -X direction side of the insertion space SI is blocked by the second base portion 72. On the other hand, the +X direction side of the insertion space SI is open to the inside of the housing 10.

[0081] The protruding portion 42 of the first engaging portion 34A is inserted into the insertion space SI from the +X direction side. The extension portion 73 faces the protruding portion 42 of the first engaging portion 34A inserted into the insertion space SI from the -Z direction side. The extension portion 73 faces the protruding portion 42 of the first engaging portion 34A inserted into the insertion space SI from the side opposite to the second main wall 12.

[0082] The extension portion 73 has a second contact portion CF2 exposed in the insertion space SI. The second contact portion CF2 contacts the first contact portion CF1 of the protruding portion 42 when the protruding portion 42 of the first engaging portion 34A is inserted into the insertion space SI. In the present embodiment, the first engaging portion 34A and the first receiving portion 64A are engaged by the first contact portion CF1 of the first engaging portion 34A and the second contact portion CF2 of the first receiving portion 64 coming into contact with each other.

[0083] In this embodiment, the second contact portion CF2 is inclined with respect to the X direction so as to be located more on the +Z direction side as it advances in the -X direction. For example, the second contact portion CF2 is inclined with respect to the X direction so that the insertion space SI becomes narrower as it advances in the -X direction. Stated from another perspective, the second contact portion CF2 is inclined with respect to the X direction such that the greater the amount of movement of the cover 60 in the +X direction (the amount of movement in the direction of inserting the protruding portion 42 into the insertion space SI) with respect to the base 30, the greater the contact force generated between the protruding portion 42 and the extending portion 73.

[0084] Stated from yet another perspective, the second contact portion CF2 is inclined at a first angle α1 with respect to the X direction so as to be located more on the +Z direction side as it advances in the -X direction. On the other hand, the first contact portion CF1 is parallel to the X direction. Alternatively, the first contact portion CF1 may be inclined at a second angle different from the first angle α1 with respect to the X direction. The second angle is, for example, an angle inclined with respect to the X direction so as to be located more on the +Z direction side as it advances in the -X direction, and is an angle smaller than the first angle α1. Alternatively, instead of the above example, the first angle α1 and the second angle may be the same angle.

[0085] <3.3 Substrate Support Portion> Next, returning to FIG. 6, the substrate support portion 65 will be described. The substrate support portion 65 is a support portion that supports the substrate 21 within the housing 10. The substrate support portion 65 has, for example, first to sixth support portions 81, 82, 83, 84, 85, 86.

[0086] The first to sixth support portions 81, 82, 83, 84, 85, 86 are protruding portions that protrude from the second main wall 12 in the -Z direction. The first to third support portions 81, 82, 83 are arranged at positions overlapping the end portion on the -Y direction side of the substrate 21 when viewed from the Z direction. The first to third support portions 81, 82, 83 are arranged separately in the X direction (see FIG. 7). The first to third support portions 81, 82, 83 face the second surface 21b of the substrate 21 from the +Z direction side and support the substrate 21. The fourth to sixth support portions 84, 85, 86 are arranged at positions overlapping the end portion on the +Y direction side of the substrate 21 when viewed from the Z direction. The fourth to sixth support portions 84, 85, 86 are arranged separately in the X direction (see FIG. 7). The fourth to sixth support portions 84, 85, 86 face the second surface 21b of the substrate 21 from the +Z direction side and support the substrate 21.

[0087] In the present embodiment, the first to sixth support portions 81, 82, 83, 84, 85, 86 face (for example, contact) the substrate 21 from the side opposite to the fourth to ninth support portions 54, 55, 56, 57, 58, 59 of the base 30. Thereby, the substrate 21 is sandwiched between the base 30 and the cover 60. Note that in the present application, "supporting the substrate" may include cases where, in the shipped state of the product, it does not contact the substrate, but when some components are deformed due to heat generation or aging deterioration of the product (for example, when the substrate is warped), it contacts the substrate and supports the substrate.

[0088] <3.4 Fixing Portion> The fixing portion 66 is a portion fixed to the fixing portion 36 of the base 30 by the fastening member 90. The fixing portion 66 is an example of a "second fixing portion". In the present embodiment, the fixing portion 66 is provided at the second end portion 10b of the housing 10. The fixing portion 66 is, for example, a protruding portion that protrudes from the second main wall 12 in the -Z direction. The fixing portion 66 is, for example, a plate portion along the Y direction and the Z direction. The fixing portion 66 is arranged at a position adjacent to the fixing portion 36 of the base 30 in the X direction. In the present embodiment, the fixing portion 66 is arranged on the -X direction side of the fixing portion 36 of the base 30 and is located between the base 30 fixing portion 36 and the substrate 21. The fixing portion 66 has an engagement hole 66h into which the fastening member 90 engages. The inner peripheral surface of the engagement hole 66h has a female thread.

[0089] <4. Fastening member> The fastening member 90 is a member that fixes the base 30 and the cover 60. In the present embodiment, the fastening member 90 fixes the fixing portion 36 of the base 30 and the fixing portion 66 of the cover 60 in a state where the first and second engaging portions 34A and 34B and the first and second receiving portions 64A and 64B are engaged with each other.

[0090] The fastening member 90 is, for example, a screw member. The fastening member 90 is arranged along the X direction. The fastening member 90 is inserted into the insertion hole 36h of the fixing portion 36 of the base 30 and engaged with the engaging hole 66h of the fixing portion 66 of the cover 60 in a state where the first and second engaging portions 34A and 34B and the first and second receiving portions 64A and 64B are engaged with each other. Note that in the present application, "the fastening member fixes the fixing portion of the base and the fixing portion of the cover in a state where the engaging portion and the receiving portion are engaged" is not limited to the case where the fixing portion of the base and the fixing portion of the cover are fixed after the engaging portion and the receiving portion are engaged. "The fastening member fixes the fixing portion of the base and the fixing portion of the cover in a state where the engaging portion and the receiving portion are engaged" may also apply to the case where it is attached to the fixing portion of the base or the fixing portion of the cover before the engaging portion and the receiving portion are engaged, and the cover moves relative to the base by tightening with the fastening member, and the engaging portion and the receiving portion are engaged.

[0091] In the present embodiment, the direction in which a force acts to move the cover 60 by rotating the fastening member 90 in the tightening direction coincides with the direction (+X direction) in which the cover 60 moves relative to the base 30 so that the contact force generated between the protruding portion 42 and the extending portion 73 increases. Therefore, when the fastening member 90 is rotated in the tightening direction, the protruding portion 42 and the extending portion 73 come into contact more reliably.

[0092] FIG. 11 is a front view showing the semiconductor memory device 1. In the present embodiment, the fastening member 90 is provided at the central portion in the Z direction of the second end portion 10b of the housing 10. In the present embodiment, except for one fastening member 90, the screw members are not exposed outside the housing 10.

[0093] <Method for manufacturing a semiconductor memory device> Next, a method for manufacturing the semiconductor memory device 1 will be described. FIG. 12 is a cross-sectional view for explaining the method for manufacturing the semiconductor memory device 1. In FIG. 12, for convenience of explanation, the illustration of the substrate unit 20 is omitted.

[0094] In the present embodiment, first, the substrate unit 20 is housed inside the base 30. Then, the substrate unit 20 is fixed to the substrate support portion 35 of the base 30 by a plurality of screw members 45 and washers 46.

[0095] Next, after the substrate unit 20 is fixed inside the base 30, the cover 60 is placed on the base 30 in a state where the cover 60 is displaced in the -X direction with respect to the base 30. For example, the lower end surface 63ce of the third side wall 63c of the cover 60 is placed on the upper end surface 33ce of the first side wall 33c of the base 30, and the lower end surface 63de of the fourth side wall 63d of the cover 60 is placed on the upper end surface 33de of the second side wall 33d of the base 30.

[0096] At this time, the guide portion 79A of the first receiving portion 64A of the cover 60 is aligned with the guide surface 39A of the first side wall 33c of the base 30, and the guide portion 79B of the second receiving portion 64B of the cover 60 is aligned with the guide surface 39B of the second side wall 33d of the base 30. Thereby, the alignment in the Y direction between the base 30 and the cover 60 is performed.

[0097] Next, as shown in FIG. 12, the cover 60 is slid in the +X direction with respect to the base 30. As a result, the protrusion 42 of the first engaging portion 34A is inserted into the insertion space SI of the first receiving portion 64A, and the protrusion 42 of the second engaging portion 34B is inserted into the insertion space SI of the second receiving portion 64B. In the present application, "moving the second member in the second direction with respect to the first member" means relatively moving the second member in the second direction with respect to the first member. That is, "moving the second member in the second direction with respect to the first member" is not limited to the case of moving the second member in the second direction (+X direction) with the position of the first member fixed, and may also apply to the case of moving the first member in the first direction (-X direction) with the position of the second member fixed.

[0098] Next, by further sliding the cover 60 in the +X direction with respect to the base 30, the first contact portion CF1 of the protrusion 42 of the first engaging portion 34A contacts the second contact portion F2 of the extending portion 73 of the first receiving portion 64A, and the first engaging portion 34A and the first receiving portion 64A are engaged. Similarly, the first contact portion CF1 of the protrusion 42 of the second engaging portion 34B contacts the second contact portion F2 of the extending portion 73 of the second receiving portion 64B, and the second engaging portion 34B and the second receiving portion 64B are engaged. Thereby, the alignment in the Z direction between the base 30 and the cover 60 is performed.

[0099] Next, the fastening member 90 is inserted through the insertion hole 36h of the fixing portion 36 of the base 30, and then engaged with the engagement hole 66h of the fixing portion 66 of the cover 60. As a result, the cover 60 cannot come off in the -X direction with respect to the base 30. Thereby, the semiconductor memory device 1 is completed.

[0100] <6. Advantages> In this embodiment, the base 30 has a first engaging portion 34A and a fixing portion 36. The first engaging portion 34A is disposed inside the housing 10 and has a base portion 41 extending in the Z direction and a protruding portion 42 extending in the -X direction from the base portion 41. The cover 60 has a first receiving portion 64A and a fixing portion 66. The first receiving portion 64A includes an insertion space SI that is open in the +X direction. When the cover 60 is moved in the +X direction with respect to the base 30, the protruding portion 42 of the first engaging portion 34A is inserted into the insertion space SI and engages with the first engaging portion 34A. The fixing portion 66 is fixed to the fixing portion 36 by a fastening member 90 in a state where the first engaging portion 34A and the first receiving portion 64A are engaged.

[0101] According to such a configuration, since the fastening member 90 is attached in a state where the base 30 and the cover 60 are engaged by the first engaging portion 34A and the first receiving portion 64A, the number of fastening members 90 required to fix the base 30 and the cover 60 can be reduced. Thereby, the number of components of the semiconductor memory device 1 can be reduced. Further, when the number of required fastening members 90 can be reduced, the fastening members 90 exposed outside the housing 10 are less likely to be conspicuous, and it becomes easier to enhance the design property of the appearance of the semiconductor memory device 1.

[0102] In this embodiment, the base portion 41 of the first engaging portion 34A extends in the Z direction from the first main wall 11. The protruding portion 42 of the first engaging portion 34A extends in the -X direction from the base portion 41 at a position away from the first side wall 33c and the second side wall 33d. With such a configuration, an engaging structure between the base 30 and the cover 60 is formed at a position different from the first side wall 33c and the second side wall 33d. For this reason, compared with the case where the first engaging portion 34A is provided on the first side wall 33c or the second side wall 33d, it is easy to increase the fixing strength between the base 30 and the cover 60.

[0103] In this embodiment, the first receiving portion 64A includes a first base portion 71 extending in the Z direction and an extending portion 73 extending from the first base portion 71 in the +Y direction and facing the protruding portion 42 of the first engaging portion 34A from the side opposite to the second main wall 12. According to such a configuration, compared with the case where the extending portion 73 extends in the X direction from the first base portion 71, for example, it is easier to improve the manufacturability of the first receiving portion 64A (such as the structure of the mold and / or the workability after casting).

[0104] In this embodiment, the extending portion 73 of the first receiving portion 64A is provided with the insertion space SI interposed therebetween from the second main wall 12. According to such a configuration, compared with the case where a structure defining the upper surface of the insertion space SI is provided separately, it is easier to secure a large insertion space SI. When a large insertion space SI is secured, the protruding portion 42 of the first engaging portion 34A can be thickened, and it is easier to increase the rigidity of the semiconductor memory device 1.

[0105] In this embodiment, a first gap g1 is provided between the first side wall 33c and the protruding portion 42 of the first engaging portion 34A. At least a part of the first base portion 71 of the first receiving portion 64A is disposed in the first gap g1. According to such a configuration, it is easier to perform the Y-direction alignment between the base 30 and the cover 60 using the first base portion 71 of the first receiving portion 64A.

[0106] In this embodiment, the first base portion 71 of the first receiving portion 64A has a first guiding portion 79A along the inner surface of the first side wall 33c. When the cover 60 is moved in the +X direction with respect to the base 30, the first guiding portion 79A is guided by the inner surface of the first side wall 33c and moved in the +X direction. According to such a configuration, the engagement between the first engaging portion 34A and the first receiving portion 64A can be performed in a state stably guided by the first guiding portion 79A. Thereby, the manufacturability of the semiconductor memory device 1 can be improved.

[0107] In this embodiment, the extension portion 73 of the first receiving portion 64A has a second contact portion CF2 that contacts the protruding portion 42 of the first engaging portion 34A. The second contact portion CF2 is inclined with respect to the X direction such that the insertion space SI becomes narrower as it progresses in the -X direction. According to such a configuration, when the protruding portion 42 is inserted into the insertion space SI, the upper end of the protruding portion 42 contacts the upper surface of the insertion space SI, and the lower end of the protruding portion 42 contacts the lower surface of the insertion space SI, so that the Z-direction position of the cover 60 with respect to the base 30 is stably determined and becomes easier to determine. Thereby, the manufacturability of the semiconductor memory device 1 can be improved.

[0108] In this embodiment, the direction in which a force acts on the cover 60 by rotating the fastening member 90 in the tightening direction coincides with the direction (+X direction) in which the cover 60 moves with respect to the base 30 such that the contact force generated between the protruding portion 42 of the first engaging portion 34A and the extension portion 73 of the first receiving portion 64A increases. According to such a configuration, by rotating the fastening member 90 in the tightening direction, the Z-direction position of the cover 60 with respect to the base 30 is more stably determined and becomes easier to determine.

[0109] <7. Variation> Next, several variations will be described. The configurations other than those described below in each variation are the same as those of the first embodiment. Note that these variations may be implemented in combination with the second embodiment.

[0110] <7.1 First Variation> FIG. 13 is a cross-sectional view showing the semiconductor memory device 1A of the first modification. In the first modification, the first contact portion CF1 is inclined at a first angle α1 with respect to the X direction so as to be positioned more on the +Z side as it proceeds in the -X direction. Stated from another perspective, the first contact portion CF1 is inclined at a first angle α1 with respect to the X direction so that the thickness of the protruding portion 42 in the Z direction increases as it proceeds in the +X direction. On the other hand, the second contact portion CF2 is parallel to the X direction. Instead of this, the second contact portion CF2 may be inclined at a second angle different from the first angle α1 with respect to the X direction. The second angle is, for example, an angle inclined with respect to the X direction so as to be positioned more on the +Z side as it proceeds in the -X direction, and is an angle smaller than the first angle α1.

[0111] According to such a configuration, as in the first embodiment, when the protruding portion 42 is inserted into the insertion space SI, the upper end of the protruding portion 42 comes into contact with the upper surface of the insertion space SI, and the lower end of the protruding portion 42 comes into contact with the lower surface of the insertion space SI, and the Z-direction position of the cover 60 with respect to the base 30 is stably determined and becomes easier to determine. Thereby, the assemblability of the semiconductor memory device 1 can be improved.

[0112] <7.2 Second Modification> FIG. 14 is a cross-sectional view showing the semiconductor memory device 1B of the second modification. In the second modification, a conductive member 101 is provided between the connection connector 22 and the second main wall 12. The conductive member 101 has flexibility and is held in a compressed state between the connection connector 22 and the second main wall 12. The conductive member 101 electrically connects the connection connector 22 and the second main wall 12. Thereby, unnecessary radiation related to the semiconductor memory device 1 can be suppressed.

[0113] (Second Embodiment) Next, the semiconductor memory device 1C of the second embodiment will be described. The second embodiment is different from the first embodiment in the content related to the shapes of the engaging portion 34 and the receiving portion 64. The configuration other than that described below is the same as the configuration of the first embodiment.

[0114] (Shape of the Engaging Portion) FIG. 15 is a perspective view showing the base 30A of the second embodiment. The base 30A has a first engaging portion 34AA and a second engaging portion 34BB. In the present embodiment, the first engaging portion 34AA and the second engaging portion 34BB have a shape that is symmetric about a virtual line L1 extending in the X direction with the center C1 of the first main wall 11 as the center line. Therefore, hereinafter, the shape of the first engaging portion 34AA will be described as a representative. The shape of the second engaging portion 34BB may be obtained by reading “-Y direction” as “+Y direction”, “+Y direction” as “-Y direction”, and “the first side wall 33c” as “the second side wall 33d” in the description of the first engaging portion 34AA described below.

[0115] In the present embodiment, the first engaging portion 34AA has a base portion 41, a protruding portion 42, and a pedestal portion 43. The pedestal portion 43 protrudes from the first main wall 11 in the +Z direction. When viewed from the Z direction, the protruding portion 42 and the pedestal portion 43 have the same shape. In the present embodiment, the space SG is defined by the lower surface of the protruding portion 42 and the upper surface of the pedestal portion 43.

[0116] In the present embodiment, the base portion 41 has an inclined portion 41s. The inclined portion 41s extends in the Z direction so as to span the protruding portion 42 and the pedestal portion 43. The inclined portion 41s is inclined with respect to the X direction so as to be located on the -Y direction side as it proceeds in the -X direction. In the present embodiment, the base portion 41, the protruding portion 42, and the pedestal portion 43 are formed by being cut out from one prism portion included in a single metal part P1. The inclined portion 41s is formed incidentally by using a cutting tool for forming the space SG between the protruding portion 42 and the pedestal portion 43. For example, when a rotary cutting tool is used as the cutting tool, the inclined portion 41s is formed in an arc shape along the rotation locus of the rotary cutting tool. According to such a configuration, it becomes easy to arrange the first engaging portion 34AA near the first side wall 33c.

[0117] (Shape of the receiving portion) FIG. 16 is a perspective view showing the cover 60A of the second embodiment. The cover 60A has a first receiving portion 64AA and a second receiving portion 64BB. In the present embodiment, the first receiving portion 64AA and the second receiving portion 64BB have a shape that is symmetric about a virtual line L2 extending in the X direction with the center C2 of the second main wall 12 as the center line. For this reason, hereinafter, the shape of the first receiving portion 64AA will be described as representative. The shape of the second receiving portion 64BB may be obtained by reading “-Y direction” as “+Y direction”, “+Y direction” as “-Y direction”, “the first engaging portion 34AA” as “the second engaging portion 34BB”, “the third side wall 63c” as “the fourth side wall 63d”, “the lower end surface 63ce of the third side wall 63c” as “the lower end surface 64ce of the fourth side wall 64c”, “the first gap g1” as “the third gap g3”, “the first guiding surface 39A” as “the second guiding surface 39B”, and “the first guiding portion 79A” as “the second guiding portion 79B” in the description of the first receiving portion 64AA described below.

[0118] The shapes of the first receiving portion 64AA and the second receiving portion 64BB are U-shaped as compared with the first embodiment. With this shape, it is possible to provide the first receiving portion 64AA and the second receiving portion 64BB in a smaller space than in the first embodiment. Further, events such as looseness occurring during casting of the first receiving portion 64AA and the second receiving portion 64BB (a large number of small cavity portions are formed in the casting) are less likely to occur.

[0119] In the present embodiment, the first receiving portion 64AA has a first base portion 71 and an extending portion 73. In the present embodiment, the second base portion 72 does not exist.

[0120] (The first base portion) The first base portion 71 extends in the -Z direction from the second main wall 12. At least a part of the first base portion 71 is adjacent to the third side wall 63c in the Y direction and is connected to the third side wall 63c in the Y direction. In the present embodiment, the first base portion 71 extends beyond the lower end surface 63ce (boundary portion B between the base 30A and the cover 60A) of the third side wall 63c to the -Z direction side. The first base portion 71 is a columnar portion having a quadrangular prism shape along the X and Y directions. The width W71 (for example, the maximum width) of the first base portion 71 in the Y direction is, for example, equal to or greater than the thickness W63c of the third side wall 63c in the Y direction. The first base portion 71 supports the extension portion 73 from the -Y direction side.

[0121] In the present embodiment, at least a part of the first base portion 71 is inserted into the first gap g1 between the first engaging portion 34AA and the first side wall 33c. The first base portion 71 has a guiding portion 79A along the inner surface of the first side wall 33c. The guiding portion 79A, for example, follows the guiding surface 39A of the first side wall 33c. In the process of combining the base 30A and the cover 60A, the guiding portion 79A is guided by the guiding surface 39A of the first side wall 33c and is slid in the +X direction.

[0122] (Extension portion) The extension portion 73 of the present embodiment extends in the +Y direction from the -Z direction side end of the first base portion 71 (see FIG. 16). At least a part of the extension portion 73 is located, for example, on the -Z direction side of the lower end surface 63ce (boundary portion B between the base 30A and the cover 60A) of the third side wall 63c. The extension portion 73 is located away from the second main wall 12. An insertion space SI is defined by the upper surface of the extension portion 73 and the lower surface of the second main wall 12 between the extension portion 73 and the second main wall 12.

[0123] The -Y direction side of the insertion space SI is blocked by the first base portion 71 (see FIG. 16). On the other hand, the +Y direction side of the insertion space SI is open to the inside of the housing 10 (see FIG. 16). In the present embodiment, the -X direction side and the +X direction side of the insertion space SI are open to the inside of the housing 10.

[0124] Into the insertion space SI, the protruding portion 42 of the first engaging portion 34AA is inserted from the +X direction side. The extending portion 73 faces the protruding portion 42 of the first engaging portion 34AA inserted into the insertion space SI from the -Z direction side. The extending portion 73 faces the protruding portion 42 of the first engaging portion 34AA inserted into the insertion space SI from the side opposite to the second main wall 12.

[0125] The extending portion 73 has a second contact portion CF2 that is exposed in the insertion space SI. The second contact portion CF2 comes into contact with the first contact portion CF1 of the protruding portion 42 when the protruding portion 42 of the first engaging portion 34AA is inserted into the insertion space SI. In the present embodiment, the first engaging portion 34AA and the first receiving portion 64AA are engaged by the first contact portion CF1 of the first engaging portion 34AA and the second contact portion CF2 of the first receiving portion 64AA coming into contact with each other.

[0126] FIG. 17 is a cross-sectional view showing a partially enlarged view of the semiconductor memory device 1C according to the second embodiment. In the present embodiment, the second contact portion CF2 is inclined with respect to the X direction so as to be positioned more on the +Z direction side as it advances in the -X direction. For example, the second contact portion CF2 is inclined with respect to the X direction so that the insertion space SI becomes narrower as it advances in the -X direction. Stated from another perspective, the second contact portion CF2 is inclined with respect to the X direction so that the contact force generated between the protruding portion 42 and the extending portion 73 becomes larger as the +X direction movement amount of the cover 60A with respect to the base 30A (the movement amount in the direction of inserting the protruding portion 42 into the insertion space SI) becomes larger.

[0127] Stated from yet another perspective, the second contact portion CF2 is inclined with respect to the X direction at a first angle α2 so as to be positioned more on the +Z direction side as it advances in the -X direction. On the other hand, the first contact portion CF1 is parallel to the X direction. Instead of this, the first contact portion CF1 may be inclined at a second angle different from the first angle α2 with respect to the X direction. The second angle is, for example, an angle inclined with respect to the X direction so as to be positioned more on the +Z direction side as it advances in the -X direction, and is an angle smaller than the first angle α2. Also, instead of the above example, the first angle α2 and the second angle may be the same angle.

[0128] FIG. 18 is a perspective view for explaining a method of manufacturing the semiconductor memory device 1C according to the second embodiment. In FIG. 18, for convenience of explanation, the first engaging portion 34AA and the first receiving portion 64AA are extracted and shown.

[0129] In the present embodiment, for example, in the same manner as in the first embodiment, after the substrate unit 20 is fixed inside the base 30A, the cover 60A is placed on the base 30A in a state where the cover 60A is displaced in the -X direction side with respect to the base 30A. For example, the lower end surface 63ce of the third side wall 63c of the cover 60A is placed on the upper end surface 33ce of the first side wall 33c of the base 30A, and the lower end surface 63de of the fourth side wall 63d of the cover 60A is placed on the upper end surface 33de of the second side wall 33d of the base 30A.

[0130] At this time, the guide portion 79A of the first receiving portion 64AA of the cover 60A is aligned along the guide surface 39A of the first side wall 33c of the base 30A, and the guide portion 79B of the second receiving portion 64BB of the cover 60A is aligned along the guide surface 39B of the second side wall 33d of the base 30A. Thereby, the alignment in the Y direction between the base 30A and the cover 60A is performed.

[0131] Next, as shown in FIG. 18, the cover 60A is slid in the +X direction with respect to the base 30A. As a result, the protruding portion 42 of the first engaging portion 34AA is inserted into the insertion space SI of the first receiving portion 64AA, and the protruding portion 42 of the second engaging portion 34BB is inserted into the insertion space SI of the second receiving portion 64BB.

[0132] Next, by further sliding the cover 60A in the +X direction with respect to the base 30A, the first contact portion CF1 of the protruding portion 42 of the first engaging portion 34AA contacts the second contact portion F2 of the extending portion 73 of the first receiving portion 64AA, and the first engaging portion 34AA and the first receiving portion 64AA are engaged. Similarly, the first contact portion CF1 of the protruding portion 42 of the second engaging portion 34BB contacts the second contact portion F2 of the extending portion 73 of the second receiving portion 64BB, and the second engaging portion 34BB and the second receiving portion 64BB are engaged. Thereby, the alignment in the Z direction between the base 30A and the cover 60A is performed.

[0133] According to such a configuration, similar to the first embodiment, when the protruding portion 42 is inserted into the insertion space SI, the upper end of the protruding portion 42 contacts the upper surface of the insertion space SI, and the lower end of the protruding portion 42 contacts the lower surface of the insertion space SI. Thus, the Z-direction position of the cover 60A with respect to the base 30A can be stably and easily determined. Thereby, the assemblability of the semiconductor memory device 1C can be improved.

[0134] Also, according to such a configuration, since the fastening member 90 is attached in a state where the base 30A and the cover 60A are engaged by the first engaging portion 34AA and the first receiving portion 64AA, the number of fastening members 90 required to fix the base 30A and the cover 60A can be reduced. Thereby, the number of components of the semiconductor memory device 1C can be reduced. Further, when the number of required fastening members 90 can be reduced, the fastening members 90 exposed outside the housing 10 are less conspicuous, and the design property of the appearance of the semiconductor memory device 1C can be easily improved.

[0135] As described above, several embodiments and modification examples have been explained. However, the embodiments and modification examples are not limited to the examples described above.

[0136] According to at least one of the embodiments described above, the semiconductor memory device includes a housing, a substrate, and a semiconductor memory. The housing includes a first member and a second member. The first member includes an engaging portion and a first fixing portion. The engaging portion is disposed inside the housing and includes a first portion extending in the thickness direction of the substrate and a second portion extending in a first direction along the first surface from the first portion. The first fixing portion is for attaching a fastening member. The second member includes a receiving portion and a second fixing portion. The receiving portion includes an insertion space opened in a second direction opposite to the first direction. When the second member is moved in the second direction with respect to the first member, the second portion is inserted into the insertion space and engages with the engaging portion. The second fixing portion is fixed to the first fixing portion by the fastening member in a state where the engaging portion and the receiving portion are engaged. According to such a configuration, the number of components can be reduced.

[0137] Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, as well as in the invention described in the claims and its equivalent scope.

Explanation of Reference Numerals

[0138] 1, 1A, 1B, 1C... semiconductor memory device, 10... housing, 11... first main wall, 12... second main wall, 21... substrate, 21a... first surface, 24... NAND (semiconductor memory), 30, 30A... base (first member), 33c... first side wall, 33d... second side wall, 34A, 34AA... first engaging portion, 34B, 34BB... second engaging portion, 36... fixing portion (first fixing portion), 41... base portion (first part), 42... protruding portion (second part), CF1... first contact portion, 60, 60A... cover (second member), 64A, 64AA... first receiving portion, 64B, 64BB... second receiving portion, 66... fixing portion (second fixing portion), 71... first base portion (third part), 72... second base portion, 73... extending portion (fourth part), 79A... first guiding portion, 79B... second guiding portion, 90... fastening member, S... accommodating space, SI... insertion space, g1... first gap.

Claims

1. A housing having a storage space, a substrate disposed in the storage space and having a first surface, a semiconductor memory provided on the first surface, comprising: The housing has a first member and a second member combined with the first member, and the storage space is formed between the first member and the second member. The first member is disposed inside the housing and has an engaging portion including a first portion extending in the thickness direction of the substrate and a second portion extending from the first portion in a first direction along the first surface, and a first fixing portion to which a fastening member is attached. The second member includes an insertion space opened in a second direction opposite to the first direction, and a receiving portion into which the second portion is inserted into the insertion space and engaged with the engaging portion when the second member is moved in the second direction with respect to the first member, and a second fixing portion fixed to the first fixing portion by the fastening member in a state where the engaging portion and the receiving portion are engaged. A semiconductor memory device.

2. When a direction intersecting the first direction and the thickness direction of the substrate is defined as a third direction, the first member has a first main wall facing the substrate from the thickness direction of the substrate, a first side wall extending in the thickness direction of the substrate from an end portion of the first main wall in the third direction, and a second side wall extending in the thickness direction of the substrate from the other end portion of the first main wall in the third direction. The first portion extends in the thickness direction of the substrate from the first main wall. The second portion extends in the first direction from the first portion at a position away from the first side wall and the second side wall. The semiconductor memory device according to claim 1.

3. The second member has a second main wall facing the substrate from a side opposite to the first main wall. The receiving portion includes a third portion extending in the thickness direction of the substrate from the second main wall, and a fourth portion extending in the third direction from the third portion and facing the second portion from a side opposite to the second main wall. The semiconductor memory device according to claim 2.

4. The fourth portion has a contact portion in contact with the second portion. The contact portion is inclined with respect to the first direction such that the insertion space becomes narrower as it progresses in the first direction. The semiconductor memory device according to claim 3.

5. The second portion has a contact portion in contact with the fourth portion. The contact portion is inclined with respect to the first direction such that the second portion becomes thicker as it progresses in the second direction. The semiconductor memory device according to claim 3.

6. The third part has a first contact portion. The fourth part has a second contact portion that contacts the first contact portion. One of the first contact portion and the second contact portion is inclined at a first angle with respect to the first direction. The other of the first contact portion and the second contact portion is parallel to the first direction. The semiconductor memory device according to claim 3.

7. The third part has a first contact portion. The fourth part has a second contact portion that contacts the first contact portion. One of the first contact portion and the second contact portion is inclined at a first angle with respect to the first direction. The other of the first contact portion and the second contact portion is inclined at a second angle different from the first angle with respect to the first direction. The semiconductor memory device according to claim 3.

8. The fastening member is a screw member arranged along the first direction. The first fixing portion has an insertion hole through which the screw member is inserted. The second fixing portion is arranged between the first fixing portion and the substrate and has an engagement hole with which the screw member passed through the insertion hole engages. The direction of the force acting on the second member by rotating the screw member in the tightening direction coincides with the direction in which the second member moves with respect to the first member so that the contact force generated between the second part and the fourth part increases. The semiconductor memory device according to claim 6 or claim 7.

9. The fourth part is provided with the insertion space interposed from the second main wall. The semiconductor memory device according to claim 3.

10. A first gap is provided between the first side wall and the second part. At least a part of the third part is arranged in the first gap. The semiconductor memory device according to claim 3 or claim 9.

11. The third part has a guiding portion along the inner surface of the first side wall. When the second member is moved in the second direction with respect to the first member, the guiding portion is guided by the inner surface of the first side wall and moved in the second direction. The semiconductor memory device according to claim 10.

12. The fourth part has a contact portion that contacts the second part. The contact portion is inclined with respect to the first direction so that the insertion space becomes narrower as it advances in the first direction. The semiconductor memory device according to claim 9.

13. The second part has a contact portion that contacts the fourth part. The contact portion is inclined with respect to the first direction so that the second part becomes thicker as it advances in the second direction. The semiconductor memory device according to claim 9.

14. The first member including the first main wall, the first side wall, the second side wall, and the engaging portion is a single-piece first component integrally formed by die casting, The second member including the second main wall and the receiving portion is a single-piece second component integrally formed by die casting. The semiconductor memory device according to claim 3 or claim 9.

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