KR100618896B1 - Electromagnetic wave shielding structure for hard disk drive - Google Patents

Abstract

An electromagnetic shielding structure of a hard disk drive is disclosed. The disclosed hard disk drive includes a housing comprising a base member and a cover member, a spindle motor installed inside the housing for rotating the disk for data storage, and a read / write head installed inside the housing for recording and reproducing data. An actuator is provided for moving to a predetermined position on the disc, and a plurality of electrical contacts are provided between the base member and the cover member to prevent radiation of the electromagnetic waves, and the plurality of electrical contacts are used for recording and reproducing data along the edge of the housing. It is arranged at intervals shorter than 1/4 of the wavelength of the frequency to be. The plurality of electrical contacts may be provided by additional screws or conductive tapes or conductive brackets disposed at both intermediate portions in the longitudinal direction of the housing with a plurality of screws for engaging the base member and the cover member. According to such a configuration, it is possible to effectively prevent the electromagnetic interference (EMI) generated by the electromagnetic radiation inside the hard disk drive to the outside.

Description

Electromagnetic wave shielding structure for hard disk drive

1 is an exploded perspective view showing the structure of a conventional hard disk drive.

FIG. 2 is a view showing simulation results of electromagnetic radiation having a frequency of 800 MHz in the conventional hard disk drive shown in FIG. 1.

FIG. 3 is a diagram illustrating an electromagnetic wave measurement position in a near field test for 800 MHz electromagnetic radiation according to the position of the conventional hard disk drive shown in FIG. 1.

4 is an exploded perspective view showing a hard disk drive employing the electromagnetic shielding structure according to the first embodiment of the present invention.

5 is a perspective view partially illustrating a housing of a hard disk drive employing an electromagnetic shielding structure according to a second embodiment of the present invention.

6 is a perspective view partially illustrating a housing of a hard disk drive employing an electromagnetic shielding structure according to a third embodiment of the present invention.

FIG. 7 is a diagram illustrating a simulation result of electromagnetic radiation having a frequency of 800 MHz in the hard disk drive according to the first embodiment of the present invention shown in FIG. 4.

FIG. 8 is a graph showing measurement results of electromagnetic radiation according to frequency in the hard disk drive according to the second embodiment of the present invention shown in FIG. 5 compared with the related art.

<Explanation of symbols for the main parts of the drawings>

110 ... housing 111 ... without base

112 Cover element 119a, 119b Screw

120 ... disk 130 ... spindle motor

140 ... actuator 141 ... pivot bearing

142 ... swing arm 143 ... suspension

145 ... Voice coil motor 148 ... Slider

150 ... gasket 160 ... conductive tape

170 Conductive Bracket 171,172 Hook

173,174 ... Home

The present invention relates to a hard disk drive, and more particularly, to an electromagnetic shielding structure of a hard disk drive for preventing electromagnetic waves emitted from the inside of the hard disk drive to cause electromagnetic interference (EMI).

A hard disk drive (HDD), which is one of information storage devices of a computer, is a device for reproducing data stored on a disc or recording data on a disc using a read / write head. In such a hard disk drive, the head performs its function while being moved to a desired position by an actuator in a state in which the head rises a predetermined height from the recording surface of the rotating disk.

1 is an exploded perspective view showing the structure of a conventional hard disk drive.

Referring to FIG. 1, a hard disk drive includes a housing 10 including a base member 11 and a cover member 12, and a spindle motor 30 installed on the base member 11 to rotate the disk 20. And an actuator 40 for moving the read / write head for reproducing and recording data to a desired position on the disc 20.

The actuator 40 includes a swing arm 42 rotatably coupled to the pivot bearing 41 installed on the base member 11, and a slider mounted at one end of the swing arm 42 to mount the head ( A suspension 43 for elastically biasing the 48 against the surface of the disk 20 and a voice coil motor (VCM) 45 for rotating the swing arm 42.

The cover member 12 is assembled to the upper portion of the base member 11 by using a plurality of screws 19. At this time, a gasket 50 is inserted between the base member 11 and the cover member 12 to prevent dust or moisture from entering the hard disk drive. The gasket 50 is generally made of viscoelastic material, such as rubber, to also function to dampen vibrations of the hard disk drive.

In a hard disk drive having such a configuration, when a read / write head writes data to or reads data from the disk 20, a high frequency current flows in the head, thereby generating electromagnetic waves. do. When the electromagnetic waves generated in this way are radiated to the outside of the hard disk drive through a gap between the base member 11 and the cover member 12, electromagnetic interference (EMI; May cause electromagnetic interference.

In order to prevent electromagnetic radiation as described above, an electrical contact is provided between the base member 11 and the cover member 12. The electrical contact is provided by typically six screws 19 which engage the base member 11 and the cover member 12. The six screws 19 are arranged along the edge of the housing 10. Specifically, one screw 19 is disposed in each of the four corner portions of the housing 10 and in each of the two intermediate portions in the horizontal direction of the housing 10. In this case, as shown, the distance between the electrical contacts at both edge portions in the longitudinal direction of the housing 10, that is, the distance between the screws 19, is approximately 100 mm.

On the other hand, hard disk drives have recently increased track per inch (TPI) and bit per inch (BPI), which indicate recording density due to the rapid increase in data storage capacity and transfer speed. It is rising. In addition, using the AZL (Adaptive Zone Layout) technology tailored to the head characteristics, the frequency distribution used for data recording and reproduction is also diversified. As such, as the frequency used for data recording and reproducing becomes higher, the wavelength of the electromagnetic wave becomes shorter, which makes it easier to radiate outside the hard disk drive.

In general, in order to effectively block the radiation of electromagnetic waves, it is known that electrical contacts having a spacing of 1/4 wavelength or less of electromagnetic waves should be provided. In the conventional hard disk drive, as described above, when the distance between the electrical contacts becomes 100 mm, it corresponds to a quarter wavelength of electromagnetic waves having a frequency of 750 MHz. Therefore, the conventional electrical contact structure as described above has a problem that it is difficult to prevent the electromagnetic wave having a frequency higher than 750MHz to be emitted to the outside.

FIG. 2 shows simulation results for electromagnetic radiation having a frequency of 800 MHz in the conventional hard disk drive shown in FIG. 1, and Table 1 below shows 800 MHz electromagnetic waves according to the position of the conventional hard disk drive shown in FIG. Shows a near field test result for radiation, and FIG. 3 shows an electromagnetic wave measurement position.

location dBuV / m location dBuV / m P1 61.85 P9 57.12 P2 58.63 P10 39.07 P3 59.17 P11 56.36 P4 40.35 P12 49.68 P5 46.21 P13 48.93 P6 42.76 P14 54.12 P7 36.80 P15 55.14 P8 44.83 P16 56.01

2 and 3 and Table 1 above, it can be seen that the radiation of the electromagnetic wave is severe at the position (P1 ~ P3, P9 ~ P11) of the screw spacing 10cm, in particular in the position (P1 ~ P3) close to the actuator It can be seen that the radiation of the electromagnetic wave is more severe than other positions.

The present invention has been made to solve the above problems of the prior art, and in particular, to provide a hard disk drive having a structure that can effectively block the radiation of electromagnetic waves by appropriately arrange the electrical contact between the base member and the cover member. Its purpose is.

The present invention to achieve the above technical problem,

A housing having a base member and a cover member, a spindle motor provided inside the housing for rotating the disk for storing data, and a read / write head provided in the housing for recording and reproducing data, In a hard disk drive having an actuator for moving to a position,

A plurality of electrical contacts are provided between the base member and the cover member to prevent radiation of the electromagnetic waves, and the plurality of electrical contacts are shorter than 1/4 of a wavelength of a frequency used for recording and reproducing data along the edge of the housing. It provides a hard disk drive, characterized in that arranged at intervals.

In the present invention, the plurality of electrical contacts,

The base member and the cover member are fastened to each other by a plurality of screws disposed at four corner portions of the housing and at both side intermediate portions in the horizontal direction of the housing, and at least one of the at least one side disposed at both sides in the longitudinal direction of the housing. It is desirable to have additional electrical contact members of.

In the present invention, the additional electrical contact member is an additional screw fastened to the base member and the cover member, or a conductive tape attached to an outer surface or an inner surface of the housing to connect the base member and the cover member, or It may be a conductive bracket installed on the outer surface of the housing connecting the base member and the cover member.

In the present invention, the additional electrical contact member may be arranged one by one in the middle portion of both sides in the longitudinal direction of the housing.

On the other hand, the additional electrical contact member may be disposed only on one side close to the actuator of both sides in the longitudinal direction of the housing.

In addition, two or more additional electrical contact members may be disposed on at least one side of both sides in the longitudinal direction of the housing.

According to the present invention, since the electromagnetic wave inside the hard disk drive can be effectively blocked from radiating to the outside, the electromagnetic interference (EMI) phenomenon is reduced.

Hereinafter, preferred embodiments of an electromagnetic shielding structure of a hard disk drive according to the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the following drawings indicate like elements. In addition, the present invention may be applied to hard disk drives of various sizes, but for convenience of description, the following description will be made based on a 3.5-inch hard disk drive.

4 is an exploded perspective view showing a hard disk drive employing the electromagnetic shielding structure according to the first embodiment of the present invention.

Referring to FIG. 4, the hard disk drive according to the present invention is a device for reproducing data stored in the disk 120 or recording data on the disk 120. The housing includes a base member 111 and a cover member 112. 110, a spindle motor 130 and an actuator 140 installed inside the housing 110.

The base member 111 and the cover member 112 are typically made of a metallic material such as aluminum, aluminum alloy or stainless steel. The cover member 112 is assembled to the upper portion of the base member 111 by a plurality of screws (119a, 119b), and wraps and protects the disk 120, the spindle motor 130 and the actuator 140, etc. Do it.

A gasket 150 is fitted between the base member 111 and the cover member 112. The gasket 150 may seal the housing 110 to prevent dust or moisture from entering the housing 110. In addition, the gasket 150 is made of a viscoelastic material, such as rubber, so as to reduce vibration of the disk drive.

The spindle motor 130 is installed on the base member 111. At least one disk 120 is installed at the hub of the spindle motor 130 to rotate together with the hub.

The actuator 140 is for moving a read / write head for recording and reproducing data to a predetermined position on the disk 120. The actuator 140 includes a swing arm 142, a suspension 143, and a voice coil motor. 145 and a slider 148 on which a read / write head is mounted. The swing arm 142 is rotatably coupled to the pivot bearing 141 installed on the base member 111. The suspension 143 is coupled to the distal end of the swing arm 142 to support the head-mounted slider 148 elastically biased toward the surface of the disk 120. The voice coil motor 145 provides a driving force for rotating the swing arm 142, which is controlled by a servo control system, and is flammed by the interaction between a current input to the VCM coil and a magnetic field formed by a magnet. The swing arm 142 is rotated in the direction according to the left hand law. That is, when the power of the disk drive is turned on and the disk 120 starts to rotate, the voice coil motor 145 rotates the swing arm 142 in one direction to move the head over the recording surface of the disk 120. Move it. On the contrary, when the power of the disk drive is turned off and the rotation of the disk 120 stops, the voice coil motor 145 rotates the swing arm 142 in the opposite direction so that the head rotates the recording surface of the disk 120. Try to get out.

In the hard disk drive according to the present invention, the base member 111 and the cover member 112 employ an electromagnetic shielding structure to block the electromagnetic wave generated inside the hard disk drive to the outside. To this end, a plurality of electrical contacts are provided between the base member 111 and the cover member 112 to prevent radiation of the electromagnetic waves, and the plurality of electrical contacts are disposed along an edge of the housing 110. In particular, the plurality of electrical contacts are arranged at intervals shorter than one quarter of the wavelength of the frequency used for recording and reproducing data, effectively blocking the radiation of electromagnetic waves.

Specifically, in the first embodiment of the present invention, the plurality of electrical contacts are provided by a plurality of screws 119a and 119b for fastening the base member 111 and the cover member 112. In this case, the plurality of screws 119a and 119b include six screws 119a disposed one at each of four corner portions of the housing 110 and two intermediate portions in the horizontal direction of the housing 110. In particular, it further includes two screws 119b disposed one at each of the two intermediate portions in the longitudinal direction of the housing 110.

As described above, when two screws 119b are further disposed at both middle portions of the housing 110 in the longitudinal direction, electrical contacts provided at both sides of the housing 110 in the longitudinal direction, that is, the screws 119a, The spacing between 119b) is approximately 50 mm. This corresponds to a quarter wavelength of an electromagnetic wave having a frequency of 1.5 GHz. Therefore, for the electromagnetic wave whose frequency is smaller than 1.5 GHz, it is possible to reduce the radiation of the electromagnetic wave to the outside.

On the other hand, in the above, although the additional screw 119b is shown and described as being disposed on each of the two intermediate portions in the longitudinal direction of the housing 110, one or more on each of both sides in the longitudinal direction of the housing 110 This may be arranged. In addition, as described above, the additional screw 119b may be disposed only on one side of the housing 110 close to the actuator 140 having high electromagnetic radiation.

5 is a perspective view partially illustrating a housing of a hard disk drive employing an electromagnetic shielding structure according to a second embodiment of the present invention.

Referring to FIG. 5, in the second embodiment of the present disclosure, the plurality of electrical contacts may include a plurality of screws 119a and a conductive tape 160 for fastening the base member 111 and the cover member 112. Provided by In this case, the plurality of screws 119a may include six screws 119a disposed at each of four corner portions of the housing 110 and one of two intermediate portions in the horizontal direction of the housing 110. In addition, the conductive tape 160 may be disposed on each of the outer surfaces of the intermediate portions on both sides of the housing 110 in the vertical direction. The conductive tape 160 is attached to connect the base member 111 and the cover member 112, and may be made of a metal material having excellent electrical conductivity, such as a copper tape.

As described above, even when the conductive tape 160 is attached to both sides of the housing 110 in the vertical direction, the distance between the electrical contacts is reduced, so that the same electromagnetic wave shielding effect as in the above-described first embodiment can be obtained. . In addition, when the conductive tape 160 is used, its installation is simpler than that of the first embodiment using the additional screw 119b and there is no need to change the structure of the housing 110.

On the other hand, the conductive tape 160 may be attached only to one side of the longitudinal direction of the housing 110 close to the actuator 140 with high electromagnetic radiation, not on the outer surface of the housing 110 but on the inner surface of the housing 110. It may be attached.

6 is a perspective view partially illustrating a housing of a hard disk drive employing an electromagnetic shielding structure according to a third embodiment of the present invention.

Referring to FIG. 6, in the third embodiment of the present invention, the plurality of electrical contacts are connected to the plurality of screws 119a and the conductive brackets 170 that fasten the base member 111 and the cover member 112. Provided by At this time, the plurality of screws 119a is composed of six screws 119a which are disposed at each of four corner portions of the housing 110 and two intermediate portions of both sides of the housing 110 in the horizontal direction. In addition, the conductive brackets 170 may be disposed on each of the outer surfaces of both middle portions of the housing 110 in the vertical direction. The conductive bracket 170 is installed to connect the base member 111 and the cover member 112. To this end, grooves 173 and 174 are formed in the base member 111 and the cover member 112, respectively. Hooks 171 and 172 fitted into the grooves 173 and 174 are provided at both ends of the conductive bracket 170, respectively. The conductive bracket 170 may be made of a metal material having excellent electrical conductivity.

As described above, even when the conductive brackets 170 are coupled to both sides of the housing 110 in the longitudinal direction, the distance between the electrical contacts is reduced, so that the same electromagnetic wave shielding effect as in the above-described first embodiment can be obtained. . In addition, in the case of using the conductive bracket 170, there is an advantage that it can have a stronger durability than the above-described second embodiment using the conductive tape 160.

On the other hand, the conductive bracket 170 may be disposed only on one side in the longitudinal direction of the housing 110 close to the actuator 140 with high electromagnetic radiation.

FIG. 7 is a diagram illustrating a simulation result of electromagnetic radiation having a frequency of 800 MHz in the hard disk drive according to the first embodiment of the present invention shown in FIG. 4.

Referring to Figure 7, it can be seen that the radiation of the electromagnetic wave at the position close to the actuator is much less than in the prior art.

FIG. 8 is a graph showing measurement results of electromagnetic radiation according to frequency in the hard disk drive according to the second exemplary embodiment of the present invention in comparison with the related art, and Table 2 below summarizes the measurement results. It is.

Frequency (MHz) Prior art (dBuV / m) Second Embodiment of the Invention (ddBuV / m) 725 44.98 43.21 775 54.62 49.85 786 52.41 48.21 825 47.86 45.00 860 47.55 45.96

8 and Table 2, according to the second embodiment of the present invention, it can be seen that the radiation amount of the electromagnetic wave is reduced compared with the prior art. In particular, according to the present invention, it can be seen that the radiation dose of electromagnetic waves does not increase even if the frequency is increased.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. For example, although the present invention is illustrated and described with reference to a 3.5 inch hard disk drive, the present invention is not limited thereto and may be applied to hard disk drives of various sizes. In addition, although the screw, the conductive tape, and the conductive bracket are illustrated and described as means for providing the electrical contact in the detailed description and the drawings, various types of electrical contact providing means known to those skilled in the art may be provided. Therefore, the true technical protection scope of the present invention will be defined by the appended claims.

As described above, according to the present invention, since electrical contacts disposed at appropriate intervals are provided between the base member and the cover member, electromagnetic waves having a high frequency can be effectively prevented from being radiated to the outside of the hard disk drive. Therefore, malfunction of the peripheral device due to the electromagnetic interference (EMI) phenomenon is prevented and the operation reliability of the hard disk drive is improved.

Claims (10)

A housing having a base member and a cover member, a spindle motor provided inside the housing for rotating the disk for storing data, and a read / write head provided in the housing for recording and reproducing data, In a hard disk drive having an actuator for moving to a position, A plurality of electrical contacts are provided between the base member and the cover member to prevent radiation of the electromagnetic waves, and the plurality of electrical contacts are shorter than 1/4 of a wavelength of a frequency used for recording and reproducing data along the edge of the housing. Hard disk drives, characterized in that arranged at intervals. The method of claim 1, wherein the plurality of electrical contacts, By fastening the base member and the cover member, a plurality of screws respectively disposed at the four corners of the housing and the two intermediate portions in the horizontal direction of the housing, And at least one additional electrical contact member disposed on at least one of both sides in the longitudinal direction of the housing. The method of claim 2, And the additional electrical contact member is an additional screw fastened to the base member and the cover member. The method of claim 2, And the additional electrical contact member is a conductive tape attached to an outer surface or an inner surface of the housing to connect the base member and the cover member. The method of claim 4, wherein And the conductive tape is made of copper. The method of claim 2. And the additional electrical contact member is a conductive bracket installed on an outer surface of the housing to connect the base member and the cover member. The method of claim 6, A groove is formed in each of the base member and the cover member, and a hook fitted into the groove is formed at both ends of the conductive bracket. The method according to any one of claims 2 to 7, And the additional electrical contact members are disposed one at each of middle portions of both sides of the housing in the longitudinal direction. The method according to any one of claims 2 to 7, And the additional electrical contact member is disposed on one side of the housing close to the actuator on both sides in the longitudinal direction of the housing. The method according to any one of claims 2 to 7, And at least two additional electrical contact members are disposed on at least one of both sides in the longitudinal direction of the housing.

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