JPH10249994A - Metal plate for electronic equipment and electronic equipment component or electronic equipment apparatus using the metal plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of obstruction of a function of a component or apparatus due to gas generated during use, with excellent moldability. SOLUTION: An organic resin film having a frictional coefficient of 0.3 or less and surface roughness Ra of 1.0 to 30μm is formed in a thickness of 6μm or more on one surface of a metal material piece having a tensile strength of 75MPa or more, a strength of 25MPa or more and an elongation of 10% or more. Since the piece having excellent mechanical properties is used and the film is formed in the thickness of 6μm or more on its one surface with the predetermined coefficient and roughness, its moldability is excellent. With the component molded with the film forming surface at its output, the component is not contaminated with gas dissipating from the film, and the component or apparatus functions satisfactory for a long term.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal plate used for a hard disk drive (HDD) device case and the like, and to an electronic device component or device using the metal plate.

[0002]

2. Description of the Related Art Hard disk drives (HDDs) are used as storage media for computers and word processors.
Aluminum die-cast material has been used for the case member of this hard disk drive. However, aluminum die-cast material is heavy and inconvenient to carry.
This is disadvantageous in terms of productivity and cost because it is carried out individually by painting or anodizing.

[0003]

Therefore, there has been proposed an aluminum alloy plate in which a chromate film is formed on an aluminum alloy plate, and an organic resin film containing a lubricant is formed thereon to improve the formability. JP-A-6-55137).
However, this aluminum alloy plate has an organic resin film formed on both sides, and when this is used for electronic equipment parts, gas is generated from the organic resin film, and the parts may malfunction or break down. was there. In addition, a lightweight aluminum plate for a floppy disk drive case with an organic resin film formed on one side of an aluminum alloy plate and having excellent strength, moldability, and electromagnetic shielding properties was proposed (Japanese Patent Publication No. 6-70870). When the hard disk case is formed by deep drawing, there is a problem that the alloy plate is broken. From such a thing,
The present inventors have conducted intensive studies on the improvement of the formability of a metal plate, and can greatly improve the formability by forming a thick organic resin film on the metal plate and defining the surface roughness. Having found that, the present inventors have further studied and completed the present invention. An object of the present invention is to provide a metal plate for electronic equipment which is excellent in moldability and does not impair the function of parts or equipment due to gas generated during use, and a part or equipment for electronic equipment using the metal plate. It is in.

[0004]

According to the first aspect of the present invention,
On one side of a metal plate having a tensile strength of 75 MPa or more, a proof stress of 25 MPa or more, and an elongation of 10% or more, a friction coefficient of 0.3
Hereinafter, there is provided a metal plate for electronic equipment, wherein an organic resin film having a surface roughness Ra of 1.0 to 30 μm is formed to a thickness of 6 μm or more.

According to a second aspect of the present invention, there is provided a metal plate for electronic equipment according to the first aspect, wherein a base film is formed on a metal base plate, and an organic resin film is formed thereon. .

According to a third aspect of the present invention, a lubricant is contained in the organic resin film, and the lubricant is at least one of a wax, a fluororesin, and an inorganic lubricant. 3. A metal plate for an electronic device according to 1 or 2.

[0007] The invention according to claim 4 is to provide an organic resin film,
4. The metal plate for an electronic device according to claim 1, further comprising an aggregate having a diameter larger than the thickness of the organic resin film.

The invention according to claim 5 is the metal plate for electronic equipment according to claim 4, wherein the aggregate is at least one of a nylon-based aggregate and an acrylic-based aggregate.
The aggregate is a fine resin powder contained in the organic resin film.

According to a sixth aspect of the present invention, the organic resin film comprises:
3. The method according to claim 1, wherein the resin is made of at least one of an acrylic resin, an ester resin, an ethylene resin, an epoxy resin, a phenol resin, a fluorine resin, and a polyamide resin. 3. The metal plate for an electronic device according to any one of 3, 4, and 5.

[0010] The invention according to claim 7 is based on claims 1 and 2,
An electronic device component, wherein the metal plate according to any one of 3, 4, 5, and 6 is formed and used with the surface on which the organic resin film is formed facing outward.

[0011] The invention according to claim 8 is the invention according to claims 1, 2,
An electronic apparatus, wherein the metal plate according to any one of 3, 4, 5, and 6 is formed and used with the surface on which an organic resin film is formed facing outward.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a metal plate includes
Although any metal material such as steel, stainless steel, copper, and aluminum can be used, an aluminum alloy is particularly preferable because it has the required strength, is easy to color, and is lightweight. In the present invention, the reason why the tensile strength of the metal plate is defined as 75 MPa or more and the proof stress is defined as 25 MPa or more is that the tensile strength is 75 MPa or more.
This is because the metal plate is deformed at the time of molding or assembling into a hard disk case, even if the strength is less than 25 MPa or less than 25 MPa. The reason why the elongation is specified to be 10% or more is that if it is less than 10%, fracture cracking occurs during molding. In the present invention, the reason why the organic resin film is formed on only one surface is to prevent the adverse effect of the gas generated from the organic resin by forming a component or the like with the organic resin film-formed surface outside. In the present invention, the organic resin film may be formed directly on a degreased metal plate. However, when an undercoat film is formed on a metal plate and an organic resin film is formed thereon, corrosion resistance and adhesion are improved. I do. A chemical conversion treatment, an alumite treatment, a plating method, or the like is applied to the formation of the base coat. For the chemical conversion treatment method, any treatment liquid such as a chromate-based, a zirconium-based, a titanium-based, or a phosphate-based treatment solution can be used. Among the treatment liquids, a chemical conversion treatment method using a chromate-based, zirconium-based, or titanium-based treatment liquid is desirable from the viewpoint of productivity, cost, performance stability (adhesion, and the like).

As the organic resin film, resins such as acrylic, ester, ethylene, epoxy, phenol, fluorine and polyamide resins and copolymers of these resins can be used. For forming the organic resin film, a method of painting as a paint, a method of bonding (laminating) a film-like resin, and the like are applied. When forming an organic resin film by painting, a surfactant, a leveling agent, a suspending agent,
A good finish can be obtained by adding an appropriate amount of an antistatic agent and a thickener.

In the present invention, by setting the coefficient of friction of the organic resin film to 0.3 or less, excellent moldability can be ensured. In order to reduce the friction coefficient to 0.3 or less, a method using an organic resin film having a low friction coefficient itself, a method using an organic resin to which a lubricant is added, and the like are applied. Examples of the lubricant include petroleum waxes such as polyethylene wax and polypropylene wax, natural waxes such as carnaupa wax, fluorine resin compounds such as polytetrafluoroethylene (PTFE) and polyvinylidene fluoride, and inorganic materials such as graphite and molybdenum disulfide. Lubricants, mixtures thereof, and the like are used. If the amount of the lubricant contained in the organic resin film is less than 0.5% by weight, a sufficient lubricating effect cannot be obtained. The coefficient of friction decreases as the amount of lubricant increases.
%, The adhesion between the organic resin film and the metal plate is reduced. Therefore, the suitable amount of the lubricant is 0.5 to 30% by weight.

In the present invention, if a coloring pigment or a dye is added to the organic resin film, it is possible to impart design and omit a coating step. Further, by adding a silica compound or an alumina compound, the organic resin film is strengthened and the moldability is improved. It should be noted that excessive addition of the above compound deteriorates the film performance.

In the present invention, the reason why the surface roughness Ra of the organic resin film is specified to be 1.0 to 30 μm is that when the Ra is less than 1.0 μm, the concave portion for holding the lubricating oil is too shallow and the lubricating oil is insufficient. This is because the lubricating oil cannot enter the concave portion when it exceeds 30 μm, making it difficult for the lubricating oil to come out to the surface, and the vicinity of the apex of the convex portion on the surface becomes almost non-lubricated. As a method of controlling the surface roughness Ra of the organic resin film to 1.0 to 30 μm, an arbitrary method such as a method of including an aggregate having a diameter larger than the thickness of the organic resin film in the organic resin film, a method of rolling with a rough roll, or the like Method is applied. An arbitrary aggregate such as an acrylic aggregate and a nylon aggregate can be used as the aggregate. By including the aggregate, not only the moldability is improved but also the designability is imparted. The surface roughness Ra of the organic resin film is 5 to 5.
20 μm is most desirable. The high formability in the present invention is achieved by a synergistic effect of the mechanical properties of the metal blank and the coefficient of friction and surface roughness of the organic resin film.

In the present invention, the thickness of the organic resin film is set to 6
The reason why the thickness is specified to be not less than 6 μm is that when the thickness is less than 6 μm, the resin film does not extend uniformly during the molding process, and the convex portions of the resin film fall off to deteriorate the moldability. However, when the organic resin film is too thick, the internal stress of the film increases, and the resin film cannot follow the deformation of the metal base plate during molding and peels off. Therefore, the thickness is preferably 50 μm or less. Two or more organic resin films can be formed in order to improve adhesion and corrosion resistance. When formed in two or more layers, adhesion and corrosion resistance are further improved.

[0018]

The present invention will be described below in detail with reference to examples. (Example 1) An aluminum alloy plate (metal plate) having a thickness of 0.75 mm shown in Table 1 was sequentially degreased, washed with water, and grounded, and an organic resin film was formed thereon to obtain a metal plate for electronic equipment. . Fine cleaner 364S manufactured by Nippon Parkerizing Co., Ltd. was used for the degreasing. The base treatment was performed by any of the methods shown in Table 2. The organic resin shown in Table 3 was used for the organic resin film. The organic resin film was formed by a coating method or a lamination method. The roughness of the organic resin film surface of the organic resin containing the aggregate depends on the thickness of the organic resin film to be formed. In addition, some of which did not undergo the base treatment were also included. A sample was cut out from the obtained metal plate, and the formability and outgas resistance were examined by the following methods. For the purpose of comparison, the same investigation was carried out for those which deviated from the conditions of the present invention. The results are shown in Tables 4 to 6. Formability A volatile lubricating oil (Nippon Kogyo Oil G-6281) is applied to the organic resin film surface of the sample, and the sample is deep drawn into a 33 mmφ cylinder so that the organic resin film surface is on the outside. LDR)
I asked. ◎, those with a limit drawing ratio (LDR) of 2.10 or more
Those with less than 2.10 and 1.90 or more were marked with ○, and those with less than 1.90 were marked with x. Outgas resistance The outgas resistance of the surface on which the organic resin film was not formed (the surface serving as the inner surface of the case) was examined. The inspection method was to seal the surface of the sample on which the organic resin film was formed, leave it in a closed container maintained at 80 ° C for 24 hours, and then return the container to room temperature to allow the gas released from the sample to aggregate on the inner surface of the container. Then, the inner surface of the container is washed with a solvent (isopropylene) to dissolve the agglomerated gas in the solvent.
(Fourier transform infrared spectroscopy) was used for gas analysis. For comparison, an organic resin film formed on both sides of a metal base plate was also tested, but only one surface was sealed, and the other surface was left with the organic resin film exposed.

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

[Table 3]

[0022]

[Table 4] (Note) #: Roughening by aggregate.

[0023]

[Table 5] (Note) #: Surface roughening by aggregate, Δ: Surface roughening by roll (roll transfer).

[0024]

[Table 6] (Note) ☆: Example of the present invention, #: surface roughening by aggregate.

As is clear from Tables 4 to 6, all of the inventive examples (Nos. 1 to 19) are excellent in moldability and outgassing resistance. On the other hand, Nos. 20 and 21 of Comparative Examples did not have an organic resin film formed, and thus fractured during molding. No.22 has a low yield strength of the metal base plate.
In each case, the elongation of the metal base plate was low, so that all were inferior in moldability. In No. 24, the organic resin film was thin, and the resin film peeled off during molding, causing breakage. No. 25 has no organic resin film and no aggregate, and has low surface roughness.
Because the film thickness was smaller than the diameter of the aggregate, the surface roughness was too large, and sufficient lubricity could not be obtained,
Breakage occurred during molding. No. 27 broke during molding due to the use of an organic resin film with a large coefficient of friction.
In No. 28, a large amount of gas was generated because the organic resin film was formed on both sides.

(Example 2) The metal plate of the present invention obtained in Example 1 was deep drawn into a box shape with the surface on which the organic resin film was formed facing outward, and this was used as an outer frame of an HDD cassette. Using. After long-term use, no deterioration of the cassette function was observed.

Although an example in which an aluminum alloy plate is used as a metal plate and the case is used for a case of an HDD cassette has been described above, the present invention relates to a case where a copper plate or a steel plate other than an aluminum alloy plate is used for an apparatus such as a computer or a word processor. The same effect can be obtained by applying the present invention to a constituent member.

[0028]

As described above, the metal plate of the present invention uses a metal base plate having excellent mechanical properties, and has an organic resin film on one side having a thickness of at least 6 μm and a predetermined friction coefficient and surface. Since it is formed with roughness, it has excellent moldability.
In addition, by molding a component or the like with the surface on which the organic resin film is formed facing outward, the component or the like does not become contaminated by gas released from the organic resin film, and the component or device functions well for a long period of time.

Claims (8)

[Claims] 1. A tensile strength of at least 75 MPa and a proof stress of 25.
The friction coefficient is 0.3 or less, and the surface roughness Ra is 1.0 to 30 μm on one surface of a metal plate having an elongation of 10 MPa or more and a MPa or more.
Wherein the organic resin film is formed to a thickness of 6 μm or more. 2. The metal plate for electronic equipment according to claim 1, wherein a base film is formed on the metal base plate, and an organic resin film is formed thereon. 3. The organic resin film according to claim 1, wherein a lubricant is contained in the organic resin film, and the lubricant is at least one of a wax, a fluororesin, and an inorganic lubricant.
Or the metal plate for electronic equipment according to 2. 4. The metal plate for electronic equipment according to claim 1, wherein the organic resin film contains an aggregate having a diameter larger than the thickness of the organic resin film. 5. The aggregate according to claim 4, wherein the aggregate is at least one of a nylon-based aggregate and an acrylic-based aggregate.
The metal plate for an electronic device according to the above. 6. The organic resin film is composed of at least one of an acrylic resin, an ester resin, an ethylene resin, an epoxy resin, a phenol resin, a fluorine resin, and a polyamide resin. The metal plate for an electronic device according to any one of claims 1, 2, 3, 4, and 5, wherein 7. An electron, wherein the metal plate according to any one of claims 1, 2, 3, 4, 5, and 6 is formed and used, with the surface on which the organic resin film is formed facing outward. Equipment parts. 8. An electronic device, wherein the metal plate according to claim 1, 2, 3, 4, 5, or 6, is formed and used, with the organic resin film forming surface facing outward. Equipment and devices.