Method for manufacturing a plate member and plate member

Abstract

The present invention provides a method for manufacturing a plate member and a plate member that can suppress deformation during manufacturing without compromising its appearance. [Solution] A method for manufacturing a plate member that constitutes part of a semiconductor memory device, wherein a plate-shaped body 41 including a thin-walled portion 42 and a thick-walled portion 43, and an intermediate body 5 including at least one flange 51 connected to the body 41 are formed by casting using molds 61 and 62, an electrodeposited coating film 47 is formed on the intermediate body 5 by applying current to the body 41 via the flange 51, and the connection portion 53 between the body 41 and the flange 51 is cut.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a plate member and a plate member. [Background Art]

[0002] In recent years, demand for nearline storage has been increasing, and the trend toward larger capacity and lower power consumption is growing. Under such circumstances, hard disk drives (HDDs) are becoming mainstream as storage media (see Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2024-072789 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] On the other hand, as storage devices for nearline storage, semiconductor storage devices (so-called SSDs) are also attracting attention. Some casings of semiconductor storage devices use cast aluminum alloy products, and electrodeposition coating is applied as a surface treatment therefor. For this reason, the cover member (hereinafter referred to as "cover") is also required to be subjected to electrodeposition coating in the same manner as the base member (hereinafter referred to as "casing").

[0005] To perform electrodeposition coating, it is necessary to provide a current-carrying point for passing current through the object to be coated. However, for the cover, there is a problem that it is difficult in terms of appearance to provide a current-carrying point for electrodeposition coating inside the product. Furthermore, the cover is relatively thin. Therefore, deformation may occur due to attachment / detachment of a jig during manufacturing, and flatness may be impaired.

[0006] An object of the present invention is to provide a method for manufacturing a plate member and a plate member that can suppress deformation during manufacturing without impairing the appearance. [Means for solving the problem]

[0007] A method for manufacturing a plate member constituting a part of a semiconductor memory device according to a first aspect of the present invention includes forming a plate-shaped body including a thin-walled portion and a thick-walled portion, and an intermediate body including at least one flange connected to the body by casting using a mold, forming an electrodeposited coating film on the intermediate body by applying current to the body through the flange, and cutting the connection portion between the body and the flange.

[0008] A plate member constituting a part of a semiconductor memory according to a second aspect of the present invention comprises a main body which is a plate-shaped casting and an electrodeposited coating film formed on the surface of the main body, wherein the edge of the main body includes a projection that protrudes in the direction of extension of the main body, the electrodeposited coating film is not formed on the tip surface of the projection, and the main body does not have contacts that conduct electricity during electrodeposition coating. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a method for manufacturing a plate member and a plate member that can suppress deformation during manufacturing without impairing its appearance. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a perspective view showing an example of the configuration of a semiconductor memory device in which a plate member according to the embodiment is applied as a cover. [Figure 2] Figure 2 is a perspective view of the cover shown in Figure 1, seen from the inside. [Figure 3] Figure 3 is a perspective view of an intermediate according to the embodiment. [Figure 4] Figure 4 is a flowchart of the manufacturing method according to the embodiment. [Figure 5A] Figure 5A is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 5B] Figure 5B is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 5C]Figure 5C is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 5D] Figure 5D is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 5E] Figure 5E is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 5F] Figure 5F is a cross-sectional view showing one step of the manufacturing method according to the embodiment. [Figure 6] Figure 6 is an enlarged perspective view of the cover according to this embodiment. [Modes for carrying out the invention]

[0011] Several embodiments will be described below with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Furthermore, the plate member according to the embodiment can be applied, for example, as a cover for the housing of a semiconductor memory device (solid state drive: SSD) (see Figure 1). However, the plate member according to the embodiment is not limited to the aforementioned cover and can be applied as other components in a semiconductor memory device. Hereinafter, for convenience, the semiconductor memory device will be referred to as SSD.

[0012] For the sake of explanation, we define the X, Y, and Z directions as mutually orthogonal. The X direction is the width direction of the SSD, the Y direction is the depth direction of the SSD, and the Z direction is the thickness direction of the SSD.

[0013] First, the configuration of SSD1 will be described. Figure 1 is a perspective view showing an example of the configuration of SSD1 in which the plate member according to this embodiment is applied as a cover. As shown in Figure 1, SSD1 comprises a housing 2, a circuit section 3, and a cover 4.

[0014] The housing 2 includes a bottom wall 21 and side walls 22, 23. The bottom wall 21 is a flat plate extending in the X direction and the Y direction. The side walls 22, 23 are strip-shaped flat plates having a predetermined width along the Z direction. The side walls 22 are provided on both edges of the bottom wall 21 in the X direction, and extend in the Y direction. The side wall 23 is provided on one of both edges of the bottom wall 21 in the Y direction. Accordingly, an opening 20 that opens in the Y direction is formed on the other of the both edges of the bottom wall 21 in the Y direction. Note that a vent hole 24 may be formed in at least one of the side walls 22, 23.

[0015] The bottom wall 21 is provided with a plurality of bosses 25 for supporting the circuit unit 3. Each boss 25 is provided with a screw hole 26 or a pin 27. When viewed from the Z direction, the position of the screw hole 26 or the pin 27 matches the position of a through hole 33 formed in a substrate 31 of the circuit unit 3.

[0016] The bottom wall 21 is provided with a support portion 28 that supports the cover 4. The support portion 28 has a rectangular shape, and extends from the bottom wall 21 in the Z direction. A screw hole 29 for screwing the cover 4 is formed in the upper end surface of the support portion 28.

[0017] The circuit unit 3 includes a substrate 31 and a plurality of electronic components 32 mounted on the substrate 31. The electronic components 32 are, for example, semiconductor elements such as controllers and memories, passive elements such as resistors and capacitors, and connectors. The above-mentioned through hole 33 is formed in the substrate 31, and a screw (not shown) or the pin 27 is inserted through the through hole 33. Accordingly, the circuit unit 3 is positioned with respect to the housing 2. Note that a plurality of substrates 31 may be provided. In this case, the plurality of substrates 31 are stacked at intervals in the Z direction.

[0018] Fig. 2 is a perspective view of the cover 4 of Fig. 1 when viewed from the inner side. The cover 4 is a plate member that covers the opening of the housing 2 in the Z direction. The cover 4 is placed on the upper end surface of the support portion 28, and is fixed to the housing 2 by being screwed through the screw hole 29.

[0019] The cover 4 has a body 41 which is a metal casting. The metal is, for example, an aluminum alloy, but is not limited thereto. The body 41 is formed, for example, in the shape of a rectangular plate extending in the X and Y directions. The body 41 also includes a thin-walled portion 42 and a thick-walled portion 43 provided on a part of the periphery of the thin-walled portion 42.

[0020] The thin-walled portion 42 is a thin plate with a thickness of approximately 2 mm or less. The surface (inner surface) of the thin-walled portion 42 facing the inside of the housing 2 may be provided with a structure such as a recess (not shown). The thick-walled portions 43 are located at the four corners of the main body 41. Through holes 44 are formed in the thick-walled portions 43 for screwing the cover 4 to the housing 2. The through holes 44 are formed in positions corresponding to the screw holes 29 of the housing 2.

[0021] The edge portion 45 of the main body 41 defines the outer circumference of the main body 41. The edge portion 45 includes a projection portion 46 that is continuous with the thin-walled portion 42. The projection portion 46 protrudes in the extending direction of the main body 41 (a direction parallel to the XY plane). For example, the projection portion 46 is provided on the portion of the edge portion 45 that extends in the Y direction and protrudes from the thin-walled portion 42 along the X direction.

[0022] An electrodeposited coating film 47 (see Figure 5D) is formed on the surface of the main body 41. The electrodeposited coating film 47 is formed by energizing the flange 51 (see Figure 3) of the intermediate body 5 (see Figure 3) which is immersed in the paint tank. Therefore, the main body 41 is energized via the flange 51 and does not have any contacts that are energized during electrodeposition coating. Furthermore, the tip surface 46a of the protruding portion 46 is a cut surface formed when the connecting portion 53 is cut in a manufacturing process described later. Therefore, no electrodeposited coating film 47 (see Figure 5D) is formed on the tip surface 46a.

[0023] Next, the manufacturing process of the cover 4 according to the manufacturing method of this embodiment will be described. Figure 4 is a flowchart of the manufacturing method of the cover 4. Figures 5A to 5F are cross-sectional views showing the steps of the manufacturing method according to this embodiment. These cross-sectional views show a cross-section that passes through the flange 51 (see Figure 3) and is parallel to the XZ plane.

[0024] First, in step S1, molds 61 and 62 are positioned. As shown in Figure 5A, the upper mold 61 and the lower mold 62 are positioned opposite each other. A cavity 63 for forming the main body 41 is defined between the upper mold 61 and the lower mold 62. A runner 64 and an overflow 65 are connected to the cavity 63. The cavity 63 is also located between the runner 64 and the overflow 65 in the X direction. That is, these arrangements assume that the molten metal 66 (see Figure 5B) flows mainly in one direction parallel to the X direction, from the runner 64 to the overflow 65.

[0025] A runner-side gate 64a is provided between the runner 64 and the cavity 63. The runner-side gate 64a is formed such that its cross-sectional area decreases as it moves from the runner 64 towards the cavity 63. Therefore, the width of the runner-side gate 64a along the Z direction narrows as it approaches the cavity 63 from the runner 64. This shape allows the runner-side gate 64a to regulate the speed and amount of molten metal 66 flowing into the cavity 63.

[0026] On the other hand, an overflow-side gate 65a is provided between the overflow 65 and the cavity 63. The overflow-side gate 65a is formed such that its cross-sectional area increases as it moves from the cavity 63 towards the overflow 65. Therefore, the width of the overflow-side gate 65a along the Z direction widens as it approaches the overflow 65 from the cavity 63. With this shape, the overflow-side gate 65a adjusts the amount of molten metal 66 flowing out of the cavity 63 so that the molten metal 66 spreads throughout the entire cavity 63.

[0027] In step S2, molten metal 66 is supplied to the mold. As shown in Figure 5B, the molten metal 66 fills the cavity 63 from the runner 64 through the runner-side gate 64a. The excess molten metal 66 flows out to the overflow 65 through the overflow-side gate 65a.

[0028] In step S3, cooling and demolding are performed. As shown in Figure 5C, after the molten metal 66 has cooled and solidified, the upper mold 61 and the lower mold 62 are separated. Then, the intermediate body 5 is removed. The intermediate body 5 includes a main body 41 and at least one flange 51 connected to the main body 41. In this example, two flanges 51 are formed. The flanges 51 are portions of the solidified molten metal 66 that are formed inside the runner 64 and the overflow 65, respectively. The main body 41 and the flanges 51 are connected to each other by a connecting portion 53 (see Figure 5E). The connecting portion 53 has the same thickness as the thin-walled portion 42.

[0029] As shown in Figure 5C, the flange 51 may be formed to be thicker than the main body 41. At a minimum, the flange 51 may be formed to be thicker than the thin-walled portion 42 (see Figure 2). After the molten metal 66 has solidified, a through hole 52 (see Figure 3) may be formed in the flange 51. For example, a hook for suspending the intermediate body 5 during electrodeposition coating is inserted through the through hole 52, and the intermediate body 5 is energized through the hook. Alternatively, the intermediate body 5 may be energized via a jig (not shown) such as a clamp for gripping the flange 51. In this case, the formation of the through hole 52 may be omitted.

[0030] In step S4, pre-treatment for painting is performed. The surface of the intermediate material 5 is degreased. Additionally, a washing treatment is performed to remove oil and foreign matter adhering to the surface. This prepares the surface of the intermediate material 5 for electrodeposition coating.

[0031] In step S5, electrodeposition coating is performed. As shown in Figure 5D, a hook for electrodeposition coating is inserted through the through hole 52 of the flange 51, and the intermediate body 5 is immersed in the coating tank. Then, by applying current through the flange 51, an electrodeposition coating film 47 is formed on the surface of the intermediate body 5. In this way, since the current is applied through the flange 51, there is no need to provide a separate structure for current application on the main body 41.

[0032] In step S6, the main body is machined. As shown in Figure 5E, with the flange 51 held or fixed by a jig (not shown), machining such as cutting is performed on the main body 41. For example, a through hole 44 is formed in the thickened portion 43. At this time, the support device such as the jig does not come into contact with the main body 41, and no direct pressure is applied from the device.

[0033] In step S7, flange removal is performed. As shown in Figure 5E, the connecting portion 53 between the main body 41 and each flange 51 is cut, and as shown in Figure 5F, each flange 51 is separated from the main body 41. This removes the flange 51 from the intermediate body 5. At this time, the connecting portion 53 may be cut so that a protruding portion 46 remains on the edge 45 of the main body 41, projecting in the direction of extension of the main body 41. Since the tip surface 46a of the protruding portion 46 is the cut surface after electrodeposition coating, as a result, no electrodeposition coating film 47 is formed on the tip surface 46a. After these steps, the cover 4 is completed.

[0034] (1) According to this embodiment, after electrodeposition coating, machining can be performed while the flange 51 connected to the main body 41 is held or fixed. Therefore, the pressure applied to the main body 41 from jigs and the like during machining is reduced, deformation of the main body 41 can be suppressed, and flatness can be maintained. This effect is particularly effective when the main body 41 is a thin plate of 2 mm or less.

[0035] Furthermore, during electrodeposition coating, since the flange 51, which is removed after electrodeposition coating, is energized, there is no need to provide an energizing structure (such as a boss) on the main body 41. In other words, the electrodeposition coating film 47 can be formed on the entire surface of the main body 41, excluding the parts that are machined, without compromising the appearance. In addition, since the aforementioned structure is unnecessary, the degree of design freedom is increased.

[0036] (2) According to this embodiment, in addition to the cavity 63 that forms the main body 41, the mold is necessarily provided with a runner 64 and an overflow 65. By actively utilizing these as flanges 51, it becomes unnecessary to separately provide a cavity in the mold for forming the flanges 51.

[0037] (3) According to this embodiment, by providing two flanges 51, each flange 51 can be held or fixed during machining after electrodeposition coating. Therefore, fluctuations and deformation of the main body 41 during machining can be further suppressed.

[0038] (4) According to this embodiment, by increasing the rigidity of the flange 51, the main body 41 is firmly supported by the flange 51, and fluctuations and deformation of the main body 41 during machining can be suppressed.

[0039] (5) According to this embodiment, the possibility of the cutting tool coming into contact with the edge 45 of the main body 41 when cutting the connecting portion 53 is reduced. Therefore, it is possible to prevent the electrodeposited coating film 47 on parts of the edge 45 other than the protruding portion 46 from being unintentionally damaged.

[0040] (6) According to this embodiment, it is not necessary to provide an electrical conduction structure (boss, etc.) on the main body 41, which increases the degree of design freedom. In addition, the electrodeposited coating film 47 can be formed on the entire surface of the main body 41 other than the parts that are machined, in other words, it is possible to avoid the occurrence of parts where the electrodeposited coating film 47 is not formed. [Explanation of symbols]

[0041] 1...Semiconductor memory device (SSD), 2...Housing, 3...Circuit section, 4...Cover (plate member), 41...Main body, 42...Thin section, 43...Thick section, 44...Through hole, 45...Edge, 46...Protruding section, 46a...Tip surface, 47...Electrodeposition coating film, 5...Intermediate body, 51...Flange, 52...Through hole, 53...Connection section, 61...Mold (upper mold), 62...Mold (lower mold), 63...Cavity, 64...Runner, 64a...Runner side gate, 65...Overflow, 65a...Overflow side gate, 66...Molten metal

Claims

1. A method for manufacturing a plate member that constitutes part of a semiconductor memory device, By casting using a mold, a plate-shaped body including a thin-walled portion and a thick-walled portion, and an intermediate body including at least one flange connected to the body are formed. By applying current to the main body via the flange, an electrodeposited coating film is formed on the intermediate body. The connection between the main body and the flange is cut. Manufacturing method.

2. In the casting described above, the flange is formed inside at least one of the runner and overflow of the mold. The manufacturing method according to claim 1.

3. In the casting described above, the flange is formed inside the runner and overflow of the mold, respectively. The manufacturing method according to claim 1.

4. In the casting described above, the flange is formed to be thicker than the thin-walled portion of the main body. The manufacturing method according to any one of claims 1 to 3.

5. The connecting portion is cut such that a protruding portion is formed on the edge of the main body that extends in the direction of the main body. The manufacturing method according to any one of claims 1 to 3.

6. A plate member that constitutes part of a semiconductor memory device, The main body is a plate-shaped casting, The electrodeposited coating film formed on the surface of the main body, Equipped with, The edge of the main body includes a projection that extends in the direction of the main body's extension. The electrodeposited coating film is not formed on the tip surface of the protruding portion. The aforementioned body does not have contacts that are energized during electrodeposition coating. plate member.

7. A semiconductor memory device comprising the plate member described in claim 6.

8. The plate member is configured as a cover for the housing of the semiconductor memory device. The semiconductor memory device according to claim 7.

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