JPH0617277Y2 - Magnetic disk unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a magnetic disk device, and more particularly to a magnetic disk device that is compact and capable of preventing interference of magnetic noise.

(Prior Art) Conventionally, a magnetic disk device used as a storage device such as a computer has been generally known.

This magnetic disk device uses a rigid magnetic disk as a recording medium, and uses a CSS (contact start stop) type magnetic head that floats from the surface of the magnetic disk by an air flow generated when the magnetic disk is rotated at a high speed. The magnetic disk is rotated at a high speed to increase the relative speed between the magnetic disk and the magnetic head, thereby increasing the recording density and increasing the storage capacity. Has been realized.

In addition, since the flying height of the magnetic head in the apparatus is extremely small as described above, the magnetic head is damaged (the head is damaged) only when fine dust such as cigarette smoke is mixed between the flying magnetic head and the magnetic disk surface. It causes an accident such as a crash).

Therefore, in this type of magnetic disk device, the entire device is housed in a sealed case to prevent dust from entering.

Further, in this type of magnetic disk device, the magnetic disk device is housed in a shield case as shown in FIG. 7 in order to shield it from electromagnetic noise, and is attached and fixed to a host device via the shield case. .

As shown in FIG. 7, this shield case includes a top cover 2 for housing the magnetic disk device 1 and a bottom cover 3
It is constituted by screwing these covers 2 and 3 with screws 4.

Further, the magnetic disk device 1 is mounted in the shield case via a vibration isolation suspension in order to prevent inadvertent vibrations from the host device from being transmitted to the device 1. The magnetic disk device 1 and the magnetic disk device 1 do not come into direct contact with each other.

(Problems to be solved by the invention) By the way, the top plate 2 of the shield case in the magnetic disk device 1 as described above is formed by bending each piece 2a around the cold-rolled steel plate.

For this reason, there is a drawback that a slight gap is inevitably formed at the joint between the bent pieces 2a of the top cover 2 and the electromagnetic noise jumps into the shield case through this gap.

In addition, the top cover 2 and the bottom cover 3 are fixed with screws 4
Even if it is screwed in, a closed loop is not formed because a gap 2a is created between the covers 2 and 3 as shown in FIG. 8 and the conduction state is incomplete. Furthermore, from this gap 2a There was a drawback that electromagnetic noise would jump into the shield case.

For this reason, the conventional magnetic disk device using such a shield case cannot obtain a sufficient shield effect.

Further, covers 2 and 3 formed of this cold rolled steel plate
Is relatively heavy and is unsuitable for the magnetic disk device 1 mounted on a laptop computer, which is particularly required to be lightweight.

Further, in order to eliminate the transmission of vibrations to the magnetic disk device 1, it is necessary to provide a space between the dust-proof case in which the magnetic disk device 1 is housed and the shield case so that they are not in contact with each other. The whole disk device was undesirably large.

(Means for Solving the Problems) The present invention has been made in view of the above circumstances, and an object thereof is to provide a magnetic disk device that has a high shielding effect, is small in size, and is excellent in earthquake resistance. And

In order to achieve this object, the present invention provides a dustproof case in which functional components such as a magnetic disk and a magnetic head are housed and sealed, a printed circuit board on which electronic components are mounted, and the printed circuit board and the dustproof case. A flexible shield case that encloses the whole in an electrically and mechanically coupled state and forms a closed loop, and is fixed to a fixing portion of another device by a screw from the outside of the shield case. And a dustproof case and a shield case are grounded.

(Embodiment) A preferred embodiment of the magnetic disk device according to the present invention will be described in detail below with reference to FIGS. 1 to 6.

In FIG. 1, a dust-proof case 10 is for sealing and dust-proofing a member such as a magnetic disk or a magnetic head that requires particularly dust-proofing. The dustproof case 10 and the printed circuit board 12 are arranged on the printed circuit board 12 located outside, and the electrical connection between the dustproof case 10 and the printed circuit board 12 is made by a flexible printed circuit board (not shown).

The dustproof case 10 has a mounting piece 10 provided around it.
a is fixed to the upper surface of the support frame 13 in the drawing by a screw 15 via an anti-vibration suspension 14, and the printed board 12 is fixed to the lower surface of the support frame 13 in the drawing by a screw 16. Has been done.

In this way, the dustproof case 10 and the printed circuit board 12 are united by the support frame 13 to form a magnetic disk device main body, and the entire magnetic disk device main body is wrapped in a flexible shield case 17 to form a magnetic disk. The device is completed.

The shield case 17 has a flexible resin sheet 17a having a thickness of about 0.1 mm to 0.3 mm and a conductive thin film 17b made of aluminum or copper coated on the surface (inner surface) to a thickness of about 10 μm to 60 μm. Is formed in a box shape or a sleeve shape.
Since it has flexibility, it can easily wrap the entire circumference of the magnetic disk device 1 without any gap,
This shields electromagnetic noise to the magnetic disk device body.

Further, the end portion of the conductive thin film 17b contacts the other portion of the conductive thin film 17b when the main body of the magnetic disk device is wrapped and forms a closed loop as a whole.

In the magnetic disk device as described above, the support frame 13 to which the dustproof case 10 and the printed circuit board 12 constituting the magnetic disk device are attached is attached by a metallic screw 18 through the attachment hole of the shield case 17. Similarly, the bracket 19 is fixed to the metallic bracket 19 and at the same time, the bracket 19 is fixed to the mechanical chassis 21 by the screw 20 so as to be fixed in the host device.

As a result, the magnetic disk device is fixed and the shield case 17 is grounded to the mechanical chassis 21 via the screw 18 and the bracket 19.

A shield case for a magnetic disk device having the above-described configuration
In the case of 17, the entire circumference of the magnetic disk device can be surely covered because it has flexibility, and there is no need to provide a gap between the shield case 17 and the dustproof case 10 and the printed circuit board 12, so that the whole Has been made smaller and thinner,
And it can be surely protected from electromagnetic noise.

However, it is needless to say that an insulating sheet is provided between the conductive portion of the printed circuit board 12 and the conductive thin film 17b of the shield case 17 when there is a possibility of electrical contact.

In such a magnetic disk device, since the dustproof case 10 is fixed to the fixed portion side via the vibration-proof suspension 14, it is absorbed by the vibration of the suspension 14 and the dustproof case 10 when an external shock is applied. Thus, the impact transmitted to each functional component in the dustproof case 10 is reduced.

Further, since the shield case 17 itself has flexibility, even if it comes into direct contact with the magnetic disk device main body portion, it does not interfere with the vibration of the magnetic disk device during shock absorption.

In particular, in the present embodiment, a material such as aluminum or copper is used as a shielding member, and by using such a material, not only low frequency noise but also noise components in a wide band from low to high frequencies are generated. Can be shielded.

Further, since this shield case 17 magnetically forms a closed loop and is grounded, the shield case 17
The charging due to the noise can be released, and the shield effect can be further improved.

Further, since the shield case 17 itself is much lighter than a hard plate shield case formed of a conventional cold-rolled steel plate, it corresponds to weight reduction of the magnetic disk device housed in the shield case 17. be able to.

By the way, in the above-described embodiment, the conductive state of the conductive thin film 17b of the shield case 17 may be incomplete.

Therefore, as shown in FIG. 2 (A), a shield case 22 made of the same material as the above-mentioned shield case 17 is composed of a main body portion 23 and a bottom portion 24, and as shown in FIG. 2 (B). To
The conductive thin film 23a of the lower folded piece 23b of the main body 23 and the conductive thin film 24a of the bottom 24 may be brought into contact with each other to achieve mutual conduction, so that a reliable conductive state may be obtained.

Further, as shown in FIG. 3 (A), both ends of the shield case 25 are folded back outward, and as shown in FIG. 3 (B), the folded pieces are brought into contact with each other to bring the conductive thin film 25a into contact with each other. You may do it.

Further, in order to secure the contact state between the conductive thin films 23a and 24a, 25a, an adhesive 26 is dispersed and adhered between the conductive thin films as shown in FIG. It may be crimped by the caulking member 27 as shown, and may be sewn together as shown in FIG.

As a result of the experiment, it was possible to obtain a sufficient conduction effect to form a closed loop in about 30% of the total area to be contacted in the portion contacted by the above-mentioned adhesion, crimping and suturing. .

(Effect of the Invention) As is apparent from the above description, since the magnetic disk device according to the present invention uses the thin and flexible shield case, it can surely cover the necessary portion without any gap and facilitates the closed loop. The magnetic disk device can be reliably protected from electromagnetic noise, and the weight and external dimensions can be made extremely small.

Furthermore, since the shield case itself has flexibility, even if it directly contacts the magnetic disk device, it does not interfere with vibrations of the magnetic disk device during shock absorption.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a magnetic disk device according to the present invention, and FIGS. 2 (A) (B) and 3 (A) (B) are other magnetic disk devices according to the present invention. FIG. 4 is a partial cutaway perspective view showing a shield case of FIG. 4 and an enlarged side sectional view of an essential part, FIG. FIG. 6 is an enlarged side sectional view of an essential part showing a state in which the ends are connected by caulking, FIG. 6 is an enlarged side sectional view of an essential part in which the ends of the shield case are connected by stitching, and FIG. 7 is a conventional magnetic disk device. FIG. 8 is an exploded perspective view showing the shield case of FIG. 10 …… Dustproof case, 12 …… Printed circuit board, 13 …… Support frame, 14 …… Suspension, 16,18,20 …… Screw, 17,22,25 …… Shield case, 17a …… Resin sheet, 17b, 23a, 24a, 25a ... Conductive thin film (conductive film), 19 ... Bracket, 21 ... Mechanical chassis.

Claims (2)

[Scope of utility model registration request] 1. A dustproof case in which functional components such as a magnetic disk and a magnetic head are housed and sealed, a printed circuit board on which electronic components are mounted, and the printed circuit board and the dustproof case are electrically and mechanically coupled to each other. The flexible shield case that encloses the entire body in a closed state and has a closed loop is formed, and the printed circuit board and the dust-proof case shield case are fixed by fixing the outside of the shield case to a fixing part of another device with a screw. A magnetic disk device characterized by being grounded. 2. The magnetic disk drive according to claim 1, wherein the shield case is formed of a material in which a conductive film is coated on the surface of a flexible resin sheet.