JPH11250432A - Disk storage device and manufacture for head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To previously prevent destruction of a read-head by preventing a noise current to a read-head consisting of MR heads especially at the time of manufacturing. SOLUTION: In HDD(hard disk drive) of a first FPC(flexible printed circuit board) 7 connected to a read-head (MR head) 3, an exposure section 72 in which one part of a read-signal line 70 for transmitting a read-signal is exposed is provided. At the time of manufacturing process of HDD, a noise current is prevented to flow in a read-head 3 side by making the read-signal line 70 a short circuit state or a ground state through the exposure section 72.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk storage device using an MR head comprising a magnetoresistive element as a read head.

[0002]

2. Description of the Related Art In recent years, hard disk drives (HD)
In D), a read / write separation type head is used as a magnetic head (hereinafter, simply referred to as a head). This read / write separation type head has a structure in which a read head and a write head are respectively mounted on a slider. The write head comprises a conventional inductive thin film head.
On the other hand, as a read head, a magnetoresistive effect element (MR
(Magnetoresistive) consisting of elements
e) A head (including a GMR head) is used.

Here, the HDD is, as shown in FIG.
A disk (magnetic disk as a storage medium) 1 rotatably mounted on a spindle motor 2, a head 3 held on a suspension 4 of a head actuator 5, and a voice coil motor (VCM) for driving the head actuator 5. 6. When the HDD is driven, the disk 1 is rotated at a high speed by the spindle motor 2. The read / write separation type head 3 has a VC
The disk is moved in the radial direction of the disk 1 by the head actuator 5 that is rotated and moved by the driving force of the M6 to read / write data from / to a track (cylinder) to be accessed.

The head 3 transmits a read signal output from the read head and a write signal to be input to the write head to a flexible printed circuit board (flexi).
ble printed circuit boar
d, hereinafter referred to as FPC) 7. FP
C7 has a plurality of signal lines for transmitting each of a read signal and a write signal, and one end is attached to a side surface of the head actuator 5 so that it can move freely according to the movement of the head actuator 5. Is configured. The other end of the FPC 7 is connected to another FPC (second FPC) 8 on which the head amplifier circuit 9 is mounted. The head amplifier circuit 9 has a read amplifier for amplifying a read signal and a write amplifier for amplifying a write signal.

[0005]

As described above, the HD
In D, input / output signals (read signal and write signal) of the head 3 are transmitted via the FPC 7. In the head 3, an output line and an input line, which are called a read, are connected to the read head and the write head, respectively. In the HDD manufacturing process, each lead of the head 3 and the FPC 7 are connected by soldering, and the FPC 7 (first FPC) and the second FPC 8 on which the head amplifier circuit 9 is mounted are connected by soldering. . In such a manufacturing process, in particular, the first F
During the step of soldering the PC 7 and the second FPC 8, noise current due to static electricity in particular may flow to the head 3 via the first FPC 7. When this noise current flows through the MR element of the read head, the MR element may be destroyed.

Accordingly, an object of the present invention is to prevent a read head from being destroyed beforehand, particularly by preventing a noise current to a read head including an MR head during a manufacturing process.

[0007]

SUMMARY OF THE INVENTION The present invention relates to an FPC (cable member) for transmitting a read signal by connecting to a read head (MR head) used in a disk storage device. And a prevention means for preventing a noise current from flowing from the signal line. Specifically, the prevention means is a short-circuit means for providing an exposed portion on a part of the FPC and short-circuiting a plurality of read signal lines connected to the read head via the exposed portion to avoid a noise current. is there. The prevention means is specifically means for grounding the read signal line.

According to the present invention, for example, when the FPC connected to the read head is connected by soldering to the second FPC on which the head amplifier circuit is mounted, the signal line of the FPC is connected by the prevention means. Can be shorted or grounded. Therefore, when static electricity is generated during the soldering process, it is possible to prevent a noise current due to the static electricity from flowing to the read head side. This can prevent a situation in which the MR element forming the read head is destroyed by the noise current, particularly during the manufacturing process.

In another aspect of the present invention, a circuit corresponding to the second FPC includes switch means for short-circuiting or grounding each signal line of the FPC connected to the read head, This is an apparatus provided with control means for controlling the switch means. With this configuration, for example, it is possible to easily operate the control circuit to short-circuit or ground each signal line of the FPC at the time of manufacturing process and to short-circuit or ground each signal line at the time of product shipment.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a conceptual diagram showing a head related to the first embodiment and its periphery.

As shown in FIG. 1, a head 3 used for an HDD has a read head 30 composed of an MR head and a write head 31 composed of an inductive thin film head.
The head 3 is connected via an FPC (referred to as a first FPC) 7 to a second FPC 8 on which a head amplifier circuit 9 is mounted (see FIG. 10). That is, the read head 30
Are connected to the read signal lines (here, two) 70 provided in the first FPC 7 and the read signal lines 70
A read signal is transmitted to the head amplifier circuit 9 (read amplifier) via the. The write head 31 is
Write signal lines (here, two) 7 provided in C7
1 and receives a write signal transmitted from the head amplifier circuit 9 (write amplifier) via the write signal line 71.

Here, as shown in FIG. 2, the head 3 is held by a suspension 4 of a head actuator 5. The first FPC 7 has one end attached to a side surface of the head actuator 5, and is configured to freely move in accordance with the movement of the head actuator 5. The other end of the FPC 7 is connected to the second FPC 8.

As shown in FIG. 1, the first FPC 7 of this embodiment is provided with an exposed portion 72 for exposing a part of the read signal line 70. The exposed portion 72 is used for short-circuiting or grounding the read signal line 70 during the manufacturing process of the HDD. That is, in the HDD manufacturing process,
For example, in the step of connecting the first FPC 7 to which the head 3 is connected to the second FPC 8 by soldering, the read signal line 70 is short-circuited or grounded using the exposed portion 72. Accordingly, when static electricity is generated during the soldering process, it is possible to prevent a noise current from flowing to the read head 30 via the read signal line 70.

Here, as a method for short-circuiting or grounding the read signal line 70 using the exposed portion 72, FIG.
As shown in FIG. 3, a conductor member 50 is provided between the suspensions 4 holding the heads 3 facing one disk.
Intervene. The conductor member 50 is connected to the ground line 51 and comes into contact with each lead signal line 70 via the exposed portion 72 of each first FPC 7. Thereby, the read signal line 70 of the first FPC 7 can be short-circuited or grounded as described above. (Modification of First Embodiment) FIG. 3 is a conceptual diagram showing a modification of the first embodiment.

In this modified example, in the second FPC 8,
Read signal line 70 connected to head amplifier circuit 9
There is provided an exposed portion 80 for exposing a part of the. In the case of this modification, in the HDD manufacturing process, the first FP
After connecting the C7 and the second FPC 8, for example, in the step of connecting the head 3 and the first FPC 7 by soldering, the read signal line 70 is short-circuited or grounded using the exposed portion 80. Accordingly, when static electricity is generated during the soldering process, it is possible to prevent a noise current from flowing to the read head 30 via the read signal line 70. A method for short-circuiting or grounding the lead signal line 70 uses a dedicated device 60 as shown in FIG.

FIG. 4 shows an application example of the present modification, in which two heads 3 are provided on the first FPC 7 and the second FPC 8.
It is assumed that groups 40Ha and 40Hb of read signal lines and write signal lines corresponding to the above are mounted.

In this application example, an exposed portion 81 that exposes a part of all the signal lines 40Ha and 40Hb of each head 3 is provided. By using the exposed portion 81, all the signal lines 40Ha and 40Hb are short-circuited or grounded, for example, at the time of connecting the head 3 and the first FPC 7 by soldering in the same manner as described above.

Here, all the signal lines 4 are
As a method for short-circuiting or grounding 0Ha and 40Hb, a dedicated device 60 as shown in FIG. 6 is used. The dedicated device 60 has a clip-like shape, and is configured so that the conductor portion 61 is pressed against the exposed portion 81 by a spring 62 to short-circuit all the signal lines 40Ha and 40Hb. The conductor 61 is grounded via a wire 63.

According to such a method, all the signal lines 40Ha and 40Hb on the second FPC 8 can be short-circuited or grounded. Therefore, when static electricity is generated during the manufacturing process, the read head 30 and the write head 31 generate noise. It is possible to prevent a current from flowing. (Second Embodiment) FIGS. 7 and 8 are block diagrams related to the second embodiment.

The first embodiment is a system in which a read signal line or a read / write signal line is short-circuited or grounded, especially during a manufacturing process of an HDD. become. On the other hand, in the second embodiment, as shown in FIG. 7, a switch circuit 92 for switching between setting and canceling of the short-circuit state is provided in the head amplifier circuit 9. As shown in FIG. 8, the head amplifier circuit 9 includes switch circuits 93a and 93b for switching between setting and canceling of the ground state.

First, as a method of switching between setting and canceling of the short-circuit state, as shown in FIG.
The input terminal 10 between the input terminals 100 and 101 of the read signal from the read head and each input terminal of the read amplifier 90 included in the head amplifier circuit 9
A switch circuit 92 is provided for switching between 0 and 101 to switch between short circuit and release. This switch circuit 92
Operates to switch between setting and canceling of the short-circuit state according to a control signal from a control circuit 91 mounted in the head amplifier circuit 9. The control circuit 91 operates according to control by, for example, a CPU, which is a main control device of the HDD, or a manual.

More specifically, during the HDD manufacturing process, the switch circuit 92 short-circuits the input terminals 100 and 101 of the read signal in the head amplifier circuit 9 in response to a control signal from the control circuit 91. With this, HDD
In the manufacturing process, for example, the first
In the process of connecting the FPC 7 to the second FPC 8 by soldering, even when static electricity is generated, it is possible to avoid a noise current from flowing through the read head 30 (see FIG. 1). When the HDD is shipped, the switch circuit 92 releases the short-circuit state of the input terminals 100 and 101 in response to a control signal from the control circuit 91. Therefore, the read amplifier 90 can input the read signal transmitted from the read head via the first FPC via the input terminals 100 and 101. That is, the read amplifier 90 can normally amplify the read signal from the read head and output it to the read / write circuit.

On the other hand, as a method for switching between setting and canceling of the grounding state, as shown in FIG.
Switch circuits 93a, 93 for switching between grounding and release of the input terminals 100, 101, respectively.
3b is provided. These switch circuits 93a, 93
b switches the setting and release of the ground state by the control signal from the control circuit 91 in the head amplifier circuit 9 as described above.

In this method, the switch circuits 93a and 93b set the input terminals 100 and 101 of the read signal in the head amplifier circuit 9 to the ground state in response to the control signal from the control circuit 91 during the manufacturing process of the HDD. . Thus, in the HDD manufacturing process, for example, the first FPC 7 to which the head 3 is connected is replaced with the second FPC 8
Even when static electricity is generated during the step of connecting by soldering, noise current can be prevented from flowing through the read head 30. Then, when the HDD is shipped, the switch circuits 93a and 93b release the short-circuit state of the input terminals 100 and 101 according to the control signal from the control circuit 91.

As described above, according to the second embodiment, the input terminals 100 and 101 connecting the read head and the read amplifier 90 are arbitrarily set to the short-circuit state or the ground state, and The grounding state can be released. Therefore, in the system of the present embodiment, unlike the first embodiment described above, the input terminals 100 and 101 can be set to the short-circuit state or the ground state even after the HDD is shipped. For this reason, not only during the manufacturing process,
For example, it is possible to set the input terminals 100 and 101 to a short-circuit state or a ground state when the HDD is not operating, thereby preventing a noise current from flowing to the read head. (Modification of Second Embodiment) FIG. 9 is a diagram showing a modification of the second embodiment. The present modified example has input terminals 100 and 1
01, the diodes 94a and 94 in opposite directions to each other.
b is connected. These diodes 94a, 94
b is connected as it is in the manufacturing process, and is also connected as it is in the shipment of HDD products. This diode 9
The forward voltage characteristics of the read heads 4a and 94b depend on the MR of the read head.
It is set according to the breakdown current characteristics of the device. With the configuration of this modification, for example, when a noise current that destroys the MR element is generated by static electricity during the manufacturing process, both ends of the read head are connected to the same potential or to the diodes 94a and 94b. , The situation in which the noise current flows to the read head can be prevented.

[0026]

As described in detail above, according to the present invention, M
In a disk storage device having a read head composed of R elements, a read signal line connected to the read head or an input terminal to a head amplifier circuit can be short-circuited or grounded, particularly during a manufacturing process. For this reason, even if a noise current that destroys the MR element is generated due to the generation of static electricity during the manufacturing process, it can be prevented from flowing to the read head side. Therefore, it is possible to prevent the MR element from being destroyed beforehand and to protect the read head from noise current.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a head related to a first embodiment of the present invention and its periphery.

FIG. 2 is a diagram showing a positional relationship between the head of the embodiment and a first FPC.

FIG. 3 is a conceptual diagram showing a modification of the embodiment.

FIG. 4 is a conceptual diagram showing an application example of the modification.

FIG. 5 is an exemplary view showing a method of short-circuiting or grounding the read signal line according to the embodiment;

FIG. 6 is a view showing a method of short-circuiting or grounding a signal line related to the application example shown in FIG. 4;

FIG. 7 is a block diagram showing a circuit on a second FPC related to the second embodiment;

FIG. 8 is a block diagram showing a circuit on a second FPC related to the second embodiment.

FIG. 9 is a block diagram showing a circuit related to a modification of the second embodiment.

FIG. 10 is a diagram showing a main part of a conventional HDD.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Disk 2 ... Spindle motor 3 ... Head (separate read / write) 4 ... Suspension 5 ... Head actuator 6 ... Voice coil motor 7 ... First FPC 8 ... Second FPC 9 ... Head amplifier circuit 30 ... Read head (MR head) 31 Write head 50 Conductor member 60 Short-circuiting specific device 70 Read signal line 71 Write signal line 72, 80, 81 Exposed portion 90 Read amplifier 91 Control circuit 92, 93a, 93b ... Switch circuits 94a and 94b ... Diodes 100 and 101 ... Input terminals

Claims (10)

[Claims] 1. A disk storage device having a head using an MR head composed of a magnetoresistive effect element as a read head and reading / writing data on a disk by the head, wherein a read / write signal is processed. A cable member having a plurality of signal lines for transmitting a read signal and a write signal by connecting a circuit for performing a read signal and a write signal, among the signal lines on the cable member, connected to the read head. A preventing means for preventing a noise current other than a read signal from flowing to the read head via the read signal line. 2. The prevention means according to claim 1, further comprising an exposed portion provided in a part of the cable member, and a short circuit of a plurality of read signal lines connected to the read head via the exposed portion to avoid the noise current. 2. The disk storage device according to claim 1, further comprising a short circuit means for performing the operation. 3. The prevention means comprises an exposed portion provided in a part of the cable member, and a plurality of read signal lines connected to the read head and a plurality of read signal lines connected to the write head via the exposed portion. 2. The disk storage device according to claim 1, further comprising short-circuit means for short-circuiting the write signal line. 4. The cable member comprises a flexible printed cable (FPC), a plurality of leads connected to the read head via an exposed portion provided on a part of a base of the FPC. 2. The disk storage according to claim 1, wherein the signal line has a structure capable of short-circuiting or grounding, and wherein the prevention means short-circuits or grounds the signal line to prevent the noise current from flowing through the read head. apparatus. 5. The first cable member comprises a flexible printed circuit board (FPC), and is connected to the head and has a first portion corresponding to a movable portion having a plurality of signal lines for transmitting the read signal and the write signal. And a second FPC on which a head amplifier circuit included in the circuit is mounted, and wherein the preventing means includes the first FPC or the second FPC.
Short-circuiting or grounding a plurality of read signal lines connected to the read head via an exposed portion provided in a part of
2. The disk storage device according to claim 1, wherein the noise current is prevented from flowing through the read head. 6. A disk storage device having a head using an MR head made of a magnetoresistive element as a read head, and reading / writing data on a disk by the head, wherein the disk storage device is connected to the read head. A cable member mounted with a plurality of read signal lines and a head amplifier circuit connected to each of the read signal lines for amplifying a read signal from the read head; and connected to a part of each of the read signal lines. A switch means for short-circuiting each of the read signal lines in response to a control signal; and a switch operation of the switch means for short-circuiting each of the read signal lines, except during a read operation by the read head. A disk storage, comprising: a control circuit for outputting a control signal. apparatus. 7. A disk storage device having a head using an MR head composed of a magnetoresistive element as a read head, wherein the head reads / writes data from / to a disk, and is connected to the read head. A cable member mounted with a plurality of read signal lines and a head amplifier circuit connected to each of the read signal lines for amplifying a read signal from the read head; and a cable member connected to each of the read signal lines. Switch means for grounding each of the read signal lines in response to a control signal, and controlling the switch means to switch the switch means for grounding each of the read signal lines other than during a read operation by the read head. A disk comprising a control circuit for outputting a signal Storage device. 8. A disk storage device having a head using an MR head composed of a magnetoresistive element as a read head, and reading / writing data on a disk by the head, wherein the disk storage device is connected to the read head. A cable member mounted with a plurality of read signal lines and a head amplifier circuit connected to each of the read signal lines for amplifying a read signal from the read head, and connected between each of the read signal lines. A disk storage device comprising: a plurality of diodes in opposite directions; and means for preventing a noise current corresponding to a breakdown current value of the MR head from flowing to the read head. 9. A method of manufacturing a head device using an MR head comprising a magnetoresistive element as a read head, wherein the cable member has a plurality of read signal lines for transmitting a read signal. A step of short-circuiting each of the read signal lines via an exposed portion provided in a part; a step of connecting each of the read signal lines short-circuited by the step to the read head; and a step of connecting the read by the step Removing the short-circuit state of each of the read signal lines after each of the read signal lines is connected to the head. 10. A method of manufacturing a head device using an MR head made of a magnetoresistive element as a read head, comprising: a cable member having a plurality of read signal lines for transmitting a read signal; A step of grounding each of the read signal lines via an exposed portion provided in a part; a step of connecting each of the read signal lines grounded in the step and the read head; Removing the ground state of each of the read signal lines after each of the read signal lines is connected to the head.