The application is based upon and claims the benefit of priority from Japanese Patent Application No. 2011-084324 filed on Apr. 6, 2011, the entire contents of which are incorporated herein by reference.
1. Field
Embodiments of the present invention relates to an electronic component and an electronic device.
2. Description of the Related Art
In recent years, with, for example, the increase of the communication amount, electronic devices capable of storing a large amount of data (information), such as a hard disk drive (HDD), have spread.
In hard disk drives, data (information) is recorded on or read from a disk which is coated with a magnetic material by rotating the disk at high speed and moving a magnetic head over the disk.
In electronic devices such as a hard disk drive, a flexible printed circuit board, for example, is used for data transfer or data communication.
The flexible printed circuit board is a printed circuit board which is flexible and hence can be deformed to a large extent. The flexible printed circuit board is also called a flexible circuit board or flexible printed circuits (FPC).
In this specification, the flexible printed circuit board is referred to as an FPC wiring board. And a reinforcement plate which supports and reinforces an FPC wiring board is referred to as an FPC reinforcement plate.
For example, in a hard disk drive, electronic components for controlling the hard disk drive are mounted on an FPC wiring board which is reinforced by an FPC reinforcement plate stuck to it.
To increase the mounting density of such electronic components, a technique may be employed in which two separate FPC reinforcement plates are laid on and engaged with each other with an FPC wiring board kept stuck to them and the FPC wiring board is thereby folded.
In this technique, the state that the FPC wiring board is folded is maintained in such a manner that, for example, a projection and a hook provided on the respective FPC reinforcement plates are engaged with each other.
A general configuration that implements the various features of embodiments will be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments and not to limit the scope of the embodiments.
According to one embodiment, an electronic component includes: an FPC wiring board in which electrical interconnections are formed on a film; a first FPC reinforcement plate which is bonded to a part of the FPC wiring board and has an opening portion; and a second FPC reinforcement plate which is bonded to another part of the FPC wiring board and has a projection which can be engaged with the opening portion of the first FPC reinforcement plate.
An embodiment will be hereinafter described with reference to the drawings.
Reference symbol 11 denotes a magnetic disk; 12, a spindle motor; 14, a magnetic head; 15, a head actuator; 16, a base stage; 17, a voice coil motor (VCM); 18a, an FPC reinforcement plate; 19, a top cover; and 20a and 20b, FPC wiring boards.
As mentioned above, the FPC wiring boards 20a and 20b are flexible printed circuit boards. For example, the FPC reinforcement plate 18a is stuck to the FPC wiring board 20b and thereby supports and mechanically reinforces it.
In the embodiment, the HDD has the base stage 16 which is shaped like, for example, a rectangular box having an open top. The base stage 16 houses the magnetic disk 11, the spindled motor 12, the magnetic head 14, the head actuator 15, the VCM 17, the FPC wiring boards 20a and 20b, the FPC reinforcement plate 18a, etc.
The magnetic disk 14 is supported by the base stage 16 via the spindle motor 12 and rotationally driven by the spindle motor 12.
Supported by the head actuator 15, the magnetic head 14 records or reads data on or from the magnetic disk 11 while moving over the magnetic disk 11.
Although not shown in
Although not shown in
The VCM 17 is disposed between a pair of yokes which are fixed to the base stage 16. The VCM 17 and a magnet which is attached to one or both of the yokes constitute a voice coil motor. When the voice coil motor is energized, the head actuator 15 having the magnetic head 14 is moved over the magnetic disk 11, whereby information is written to or read magnetically from the magnetic disk 11.
In the embodiment, the FPC wiring boards 20a and 20b are flexible printed circuit boards and, for example, constitute an integral wiring board. As shown in
A description will now be made of the flexible printed circuit board. The flexible printed circuit board is configured in such a manner that an adhesive layer is formed on a film insulator (base film) of, say, 12 to 50 μm in thickness and conductor foils of, say, 12 to 50 μm in thickness are formed on the adhesive layer. Portions other than terminal portions and soldering portions are protected being covered with an insulator.
The flexible printed circuit board can be deformed repeatedly by weak force, and its electrical characteristics are maintained even when it is deformed. For example, a polyimide film or a photosolder resist film called a coverlay is used as the insulator and the conductor foils are made of copper.
As shown in
As shown in
A part of the FPC wiring board 20b is bonded to the first FPC reinforcement plate 18a with adhesive (not shown). Another part of the FPC wiring board 20b is bonded to the second FPC reinforcement plate 18b with adhesive (not shown). The FPC wiring board 20b is thus supported and mechanically reinforced by the first FPC reinforcement plate 18a and the second FPC reinforcement plate 18b.
As shown in
In the embodiment, as shown in
In the embodiment, as shown in
As mentioned above, in the HDD, the magnetic head 14 is electrically connected to the main printed circuit board provided on the FPC wiring board 20b by the FPC wiring board 20a.
This electronic component is housed in the base stage 16 of the HDD.
Although the FPC wiring board 20b is folded as in the above embodiment, the portions that are engaged with each other are the projection 31 and the hook 32.
As shown in
As shown in
In contrast to this comparative example, as shown in
The projection 2 and the opening portion 1 are engaged with each other in the manner shown in
In the embodiment, the engagement portion which is formed by the engagement of the projection 2 and the opening portion 1 does not come into contact with the FPC wiring board 20a which serves to establish electrical connections for control of the magnetic head 14.
Therefore, the embodiment can lower the probability of occurrence of trouble that may occur in controlling the magnetic head 14 while increasing the mounting density.
Since the engagement portion which is formed by the engagement of the projection 2 and the opening portion 1 does not come into contact with the FPC wiring board 20a, it is not necessary to bond a protective member (e.g., FPC film) as used in the above comparative example to the engagement portion etc.
Therefore, a risk that a protective member peels off can be reduced. And neither a protective member nor an adhesive for bonding a protective member is necessary, which makes it possible to reduce the manufacturing costs of the electronic component and the HDD.
Since the projection 2 is generally T-shaped, it can be bent easily.
With the above configuration, the embodiment of the invention makes it possible to provide an electronic component capable of lower the probability of occurrence of trouble that may occur in controlling the magnetic head 14 while increasing the mounting density.
The invention is not limited to the above embodiment itself and, in the practice stage, may be embodied in such a manner that constituent elements are modified without departing from the spirit and scope of the invention.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.
Number | Date | Country | Kind |
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2011-084324 | Apr 2011 | JP | national |