JP3298774B2 - Magnetic head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head for recording or reproducing a magnetic signal and erasing a magnetic signal facing a magnetic recording medium such as a floppy disk, and more particularly to a magnetic head for forming a magnetic gap. The present invention relates to a magnetic head provided with ground means.

[0002]

2. Description of the Related Art A magnetic head used in a conventional floppy disk drive or the like will be described with reference to FIGS. The magnetic head shown in these figures has a front core F including a recording / reproducing core unit 1 and an erasing core unit 2. These front cores F are formed of a magnetic material such as ferrite. The recording / reproducing core unit 1 is formed by joining a T-type core 1a and an I-type core 1b.
G is formed. The erasing core 2 has a symmetrical shape with the recording / reproducing core 1, and the T-type core 2a and the I-type core 2b are joined to each other, and a magnetic gap 2G for erasing is formed at the junction. The I-shaped cores 1b and 2b are magnetically separated and bonded to each other by a non-magnetic material such as a bonding glass 3.

A resin coil bobbin 4 around which a recording / reproducing coil C1 is wound is mounted on a leg of the T-shaped core 1a. Similarly, an erasing coil C2 is mounted on a leg of the T-shaped core 2a. Is wound on the coil bobbin 5. The back core 6 is made of phosphor bronze or beryllium copper and has a spring-loaded clip 10 on one side surface of the leg tip of each of the T-shaped cores 1a and 2a and the I-shaped cores 1b and 2b projecting upward from the coil bobbins 4, 5. And press-welded. The back core 6 installed on one side surface of each of the cores 1a, 1b, 2a, and 2b at one end thereof has a back plate 10a of the clip 10 and a plurality of clip portions 10a.
The back core 6 is firmly pressed into contact with one side surface of the tip of the leg of each of the cores 1a, 1b, 2a, 2b due to the spring property of the clip 10.

The back core 6 is formed by bonding two core plates 6 a and 6 b with an adhesive glass 7. One core plate 6a is joined to one side surface of the tip of the leg of the T-shaped core 1a and the I-shaped core 1b to form a closed magnetic circuit in the recording / reproducing core 1. Similarly, the core plate 6b is joined to one side surface of the tip of the leg of the T-shaped core 2a and the I-shaped core 2b, so that a closed magnetic circuit is formed in the erasing core 2. Further, the coil bobbins 4, 5 are provided with terminal blocks 4a and 5a, respectively, made of the same resin material, and metal terminals 4b, 4c, 4c are provided above the terminal block 4a.
d has another metal terminal 5 on the top of the terminal block 5a.
b, 5c and 5d are attached. To each of these metal terminals, the start and end of the conductor forming the coils C1 and C2 are drawn out from the coils and soldered. The recording / reproducing core section 1 and the erasing core section 2 are sandwiched between two slider halves 8a and 8b constituting a non-magnetic slider 8, thereby forming a magnetic head.

[0005] The magnetic head constructed as described above is shown in FIG.
As shown in FIG. 1, a shield member 13 made of a magnetic material surrounding the slider 8 is fixed to the gimbal 11 by an adhesive (not shown). A flexible wiring board (FPC) 12 is fixed on the gimbal 11 by an adhesive (not shown). Also, metal terminals 4b, 4c, 4d and 5b, 5c, 5c provided on the bobbins 4, 5
d protrudes upward from a through hole formed in the gimbal 11 and is inserted into a small hole of the flexible wiring board 12. Then, a circuit pattern formed of conductive foil on the flexible wiring board 12 and the metal terminals 4b, 4c, 4d
And 5b, 5c and 5d are soldered.

In a floppy disk drive, a pair of magnetic heads are provided to face each other with a disk interposed therebetween.
The one (side 1 side) magnetic head located on the upper surface side of the disk is supported by a gimbal 11 as shown in FIG. The slider 8 of the other (side 0 side) magnetic head located on the lower surface side of the disk is bonded and fixed to a plate (not shown) that does not elastically deform. A flexible wiring board is similarly arranged on the back surface of this plate, and its circuit pattern is soldered to each metal terminal 4b, 4c, 4d, 5b, 5c, 5d provided on a bobbin. In these magnetic heads, the circuit pattern formed on the flexible wiring board 12 is energized to the coils C1 and C2 via the respective metal terminals.

In the magnetic head, the sliding surface side (the lower side in FIG. 6) slides on a floppy disk (magnetic recording medium) to write and read data. Static electricity is generated by the sliding friction at this time, and the front core F
The electrostatic charges are accumulated and charged. When the charge amount of the charged static electricity becomes equal to or more than a predetermined amount, an air discharge phenomenon occurs between the charged static electricity and the nearest electric conductor. When this air discharge occurs, there is a problem that not only the magnetic head but also other electronic components built around the magnetic head are adversely affected. In order to prevent such a problem from occurring, the conventional magnetic head has a structure in which the charged static electricity is released from the back core 6 to the ground circuit, as shown in FIG.
a and a lead wire A such as a tin-plated wire,
Are soldered to a ground pattern (not shown) on the flexible wiring board 12. Alternatively, as shown in FIG. 8, each core 1a, 1b, 2a, 2b of the front core F
Of the leg portion or back core 6 and the ground pattern of the gimbal 11 or the flexible wiring board 12 are electrically connected by the conductive adhesive B.

[0008]

However, in the earth connection structure shown in FIG. 7, the conductor A is soldered to the clip 10 located inside the slider 8, but within the two slider halves 8a and 8b. The work of soldering the lead wire A to the clip 10 deteriorates the workability of the soldering because the inside of the slider 8 is narrow, and when the soldering is performed in such a poor workability environment, a shock such as a drop is applied to the magnetic head. In such a case, there is a problem that a soldered portion between the clip 10 and the conductive wire A may be removed. This is because it is difficult to route the conductor in a narrow place and solder it by positioning the conductor A in a certain place and to use a soldering jig or an automatic soldering device. Therefore, it is necessary to rely on manual soldering. For this reason, the amount of solder varies, and accordingly, the soldering strength varies, which adversely affects the quality of the magnetic head. Before bonding the slider 8 to the gimbal 11, the conductor A is soldered to the clip 10, the conductor A is inserted through a hole of the gimbal 11, and the slider 8 is bonded to the gimbal 11 or the like. Since the work of soldering to the ground circuit portion on the wiring board 11 is extremely complicated and requires a large number of steps, the production quantity within a unit time is limited. Further, in the ground connection structure shown in FIG. 8, the workability deteriorates because the hardening time (lead time) of the conductive adhesive B is long. This is because the magnetic head cannot be moved until the conductive adhesive B is completely cured and stabilized, so that a large number of magnetic heads in the middle of the manufacturing process become in stock, which imposes restrictions on subsequent work processes. The present invention has been made to solve the above-mentioned conventional problems, and can reliably discharge static electricity charged in a magnetic head by reliably conducting between a core and a ground circuit portion. Another object of the present invention is to provide a magnetic head in which the work for ground connection can be simplified in a short time.

[0009]

As a first means for solving the above problems, a magnetic head according to the present invention comprises a front core forming a magnetic gap, a back core contacting the front core, and a bobbin. Metal terminal and a conductive clip that presses and clamps the front core and the back core.
And a slider that covers the back core and-flops, even without a small, ground
A circuit board on which a circuit is formed, and a part of the clip
Earth conducting terminal for conducting connection to the earth circuit
Is provided integrally, and the tip side of the ground conduction terminal is bent.
Contacting the metal terminal,
The contact portion of the through terminal and the metal terminal from the slider
Protruding outward and connecting integrally to the ground circuit.
The configuration was continued . Further, as a second means for solving the above-mentioned problem, a ground conduction terminal is provided with
And bent the tip of the ground conducting terminal to the
The clip was pressed against the metal terminal by the elastic force of the clip . Further, as a third means for solving the above-mentioned problem, the ground conduction terminal and the ground circuit of the circuit board are soldered.
And connected .

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the magnetic head of the present invention will be described below with reference to the drawings. The same members as those of the related art are denoted by the same reference numerals. First, an embodiment of the present invention will be described with reference to FIGS. In the magnetic head shown in these figures, the recording / reproducing core 1 of the front core F has a T-type core 1a and an I-type core 1b, and the erasing core 2 has a T-type core 2a and an I-type core 2b. have. All these cores are formed of a magnetic material such as ferrite. A portion facing the magnetic recording medium, or
On the lower surface of FIG. 1 serving as a sliding contact portion, the T-shaped core 1a and the I-shaped core 1b are joined via a mold glass 14a in which glass is mixed with a resin-based adhesive to improve temperature characteristics,
A magnetic gap 1G for recording / reproducing is formed. Similarly, the T-type core 2a and the I-type core 2b are joined via the mold glass 14b to form the magnetic gap 2 for erasing.
G is formed. Further, the I-type core 1b forming the recording / reproducing core 1 and the I-type core 2b forming the erasing core 2 are bonded to each other by a non-magnetic material such as an adhesive glass 3.

Coil bobbins 4 and 5 are mounted on the T-shaped core 1a forming the recording / reproducing core 1 and the T-shaped core 2a forming the erasing core 2. That is,
On the front core F, four legs 1a, 1b, 2a, 2b extending on the opposite side to the portion facing the magnetic recording medium are bonded to the I-shaped cores 1b, 2b by an adhesive glass 3 to perform recording. The reproducing core 1 and the erasing core 2 are integrally formed. The coil bobbins 4 and 5 are mounted on T-shaped cores 1a and 2a located on both outer sides of the legs. A coil C1 for recording / reproduction is wound around the coil bobbin 4, and a coil C2 is wound around the coil bobbin 5. Terminal blocks 4a, 5a are provided above the coil bobbins 4, 5, respectively, and are integrally formed of the same material as the coil bobbins 4, 5. And, three metal terminals 4b, 4c, 4d are attached to the upper surface of the terminal block 4a. Metal terminals 5b, 5c, and 5d are also mounted on the upper surface of the terminal block 5a, similarly to the terminal block 4a.
In the recording / reproducing coil C1, the metal terminals 4c and 4
d are wound around the outer periphery of the bobbin 4, and two conductors connecting the metal terminals 4b and 4c are wound around the same bobbin 4. That is, the central metal terminal 4c is used as a common terminal. This is necessary for generating a magnetic field of opposite phase during signal recording. On the other hand, since the coil C2 on the erasing side merely generates a bias magnetic field,
The ends of the conductor wound around the bobbin 15 are connected to the metal terminals 5 on both sides.
b, 5d, and the winding of the coil C2 is not connected to the central metal terminal 5c.

The back core 6 is made of phosphor bronze or beryllium copper on the side surface on the tip end side of the T-shaped cores 1a, 2a and I-shaped cores 1b, 2b projecting upward from the coil bobbins 4, 5, and is made of a spring material. It is pressed and joined by being pressed by a pressing member formed by a certain clip 16. The clip 16 is formed by connecting the back end 6 of each of the cores 1a, 1b, 2a, and 2b and the back core 6 installed on the side to the back plate 16a of the clip 16 and a plurality of clip portions 16b.
The back core 6 is firmly pressed and joined to each of the cores 1a, 1b, 2a, 2b by the elastic force of the clip 16. At this time, each of the cores 1a, 1b, 2a, 2
b, the back core 6 and the clip 16 are reliably electrically connected to each other, so that the pressure contact bonding does not come off even when a shock such as a drop is applied in a state where the magnetic head of the present invention is attached to a floppy disk device or the like. Also, the electrical continuity does not deteriorate. The clip 16 has a back plate 16a that is elongated in the longitudinal direction and is connected to the bottom surface of the clip 16 by a connecting portion 16f. In addition, the clip portion 16b has a plurality of clip portions 16b whose upper ends are bent outward diagonally upward to facilitate insertion of the back core 6, in order to facilitate insertion of the back core 6. The back plate 1
6a and a plurality of clip portions 16b are bent opposite to each other in the longitudinal direction of the clip 16;
A ground conductive terminal 16c is formed on one side surface of one of the shorter sides of the clip 16 in the same manner as the two surfaces in the longitudinal direction, and is provided integrally with the clip 16. This clip 16 has a short side 1
It is formed in a box-like shape with its surface open and bent integrally. An escape groove 16d for escaping the T-shaped core 2a and an I-shaped core 1
An escape groove 16e for escaping b, 2b is provided. The assembling of the clip 16 configured as described above will be described. The back plate 16a is positioned on the side of the slider half 8a, and the inner surface of the back plate 16a is connected to the cores 1a, 1b,
2a and 2b, the coil bobbin 4,
5 and placed between the terminal blocks 4a, 5a.
Then, the inner surface of the clip portion 16b is connected to each core 1a, 1
b, 2a and 2b, the back core 6 is pushed in against the elastic force of the clip portion 16b. Thus, each core 1a, 1b, 2a, 2b and the back core 6
Due to the elastic force of No. 6, it is firmly pressed and joined. At this time, the tip of the ground conduction terminal 16c is connected to the metal terminal 5c.
In order to make it press-contact, it is bent outward in the shape of a "ku" from the middle of the ground conduction terminal. The ground conducting terminal 16c is provided with a small hole 11 formed in a land portion of a ground pattern 17a of a flexible wiring board 12 described later.
In order to reduce the size of "e", it is preferable to press-contact the metal terminal 5c. However, when there is a space restriction in the flexible wiring board 12, the metal terminal 5c and the ground terminal 16c are not pressed into contact with each other and the flexible wiring board 1 is not pressed.
2, the holes for the metal terminals 5c may be separately provided, or the small holes 11e may be formed large and connected to the air pattern 17a.

Next, each of the cores 1a, 1b, 2a, 2b
However, the flexible wiring board 12 is used as a circuit board in this embodiment as a conductive path for connecting the metal terminal 5c in a conductive state with the clip 16 and the ground conductive terminal 16c of the clip 16 to a ground circuit. Have been. As shown in FIGS. 2 to 4, the flexible wiring board 12 is bonded and fixed to the gimbal 11 on the surface of the gimbal 11 opposite to the magnetic head bonding side. A plurality of conductive patterns 17 made of copper foil are formed on the flexible wiring board 12, which constitutes a circuit board. Six small holes 12a to 12f are formed in the lands of the plurality of conductive patterns. Further, the gimbal 11 has a through hole formed at the same position as the small holes 12a to 12f so as to have an opening area slightly larger than these small holes and not contact the metal terminal. In addition, an earth pattern 17a is formed of copper foil in the plurality of circuit patterns 17 like other circuit patterns. The small holes 11e formed in the lands of the ground pattern 17a are connected to the metal terminals 5c and the ground conductive terminals 16c.
In order for c to be inserted, the opening area is slightly larger than the other small holes.

In a state where the slider 8 of the magnetic head is adhered to the lower surface of the gimbal 11 and the flexible wiring board 12 is adhered to the upper surface of the gimbal 11, a metal terminal 4b provided on the coil bobbin 4 on the recording / reproducing side is provided. , 4c, 4
d is inserted through the through hole of the gimbal 11 and the small holes 12a, 12b, 12c of the flexible wiring board 12, and protrudes from the flexible wiring board with such a length that it can be soldered to the flexible wiring board 12. Similarly, the metal terminals 5b and 5 of the coil bobbin 5 on the erase side
c and 5d are inserted into the small holes 12d, 12e and 12f. At this time, as shown in FIG. 4, the center metal terminal 5c attached to the terminal block 5a of the coil bobbin 5 has a ground conductive terminal 16c having a length equal to or slightly shorter than the length of the metal terminal 5c. 5c. In this state, both the metal terminal 5c and the ground conduction terminal 16c are inserted into the small holes 12e. Then, the land portions of each circuit pattern 17 of the flexible wiring board 12 and the metal terminals 4b, 4c, 4d, 5b, 5c, 5d
Are connected by solder 18 and are electrically conducted. Thereby, each core 1a, 1b, 2a, 2b, 6a, 6b
Is grounded.

As another embodiment of the present invention, since the ground conducting terminal 16c of the clip 16 is pressed against the metal terminal 5c, if only the metal terminal 5c is projected from the slider 8 and soldered, each core Can be grounded as in the present invention. Also, even if there is no metal terminal 5c,
If only the ground conduction terminal 16c of the clip 16 is protruded from the slider and soldered, each core can be grounded in the same manner as in the present invention. In this case, the metal terminal 5c
The step of contacting the ground pattern with the ground conducting terminal 16c can be omitted.
The size of the small hole 11e formed in the round portion a can be reduced. Further, as another embodiment of the present invention, when the flexible wiring board 12 is not used, a lead wire is soldered to the metal terminal 5c or the ground conduction terminal 16c protruding from the slider 8, and this lead wire is soldered to a ground circuit. May be conducted. In this case, since the metal terminal 5c or the ground conductive terminal 16c protrudes from the slider 8, the space is larger than that of the conventional example shown in FIGS. As described above, there is no problem that the soldering is difficult, and the soldering can be surely performed. Further, it is preferable that the ground conductive terminal 16c be pressed against the metal terminal 5c in order to reduce the size of the small hole 11e formed in the land portion of the ground pattern 17a of the flexible wiring board 12. However, when there is no space restriction on the flexible wiring board 12, the metal terminals 5c and the ground terminals 16c are not pressed into contact with each other and the holes of the metal terminals 5c are separately provided on the flexible wiring board 12 or the small holes 11e are formed large. And may be connected to the ground pattern 17a. In this case, the step of connecting the metal terminal 5c and the ground conduction terminal 16c can be omitted. Further, the position and shape of the ground conduction terminal 16c provided on the clip 16 are not limited to the embodiment of the present invention.
Alternatively, a ground terminal may be provided extending from the clip portion 16b. Further, the ground conduction terminal 16c may be provided on the side opposite to the position of the embodiment of the present invention.

[0016]

As described above, according to the magnetic head of the present invention, the front cover for forming the magnetic gap is formed.
A, the back core in contact with the front core, and the bobbin
The provided metal terminal, the front core and the back core
Make sure that the conductive clip
A slider that covers the
A part of the clip is electrically connected to the ground circuit.
Ground connection terminal for connecting
The metal terminal is bent by bending the distal end of the conductive terminal.
To the ground conducting terminal and the metal terminal.
The contact portion is projected outward from the slider.
In addition, by connecting to the ground circuit integrally,
Space work can be performed without connecting work in a narrow space inside the lidar.
Workability is good because the connection is made at a location where the pace is large. Yo
And connect the grounding terminal to the grounding circuit without variation.
The quality of the magnetic head can be
Can be maintained. In addition, it soldered directly grounded circuit A over scan conduction terminal, static electricity charged to the magnetic head can be reliably transmitted to the outside. Also, ground conduction
The terminal is bent outward in the shape of a letter, and
The tip of the conductive terminal is connected to the gold by the elastic force of the clip.
The metal terminal before connecting.
The grounding terminal is securely positioned at
Business can be performed reliably. Also, the ground conduction terminal
And the earth circuit of the circuit board are connected by soldering.
With this, soldering can be performed in a wide space, and the workability is improved.
And the contact between the metal terminal and
Soldering to the circuit at once.
The layer work efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a magnetic head for a floppy disk drive as one embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a gimbal and a flexible wiring board are connected to the magnetic head of the present invention.

FIG. 3 is a side view of a waist section in FIG. 2;

FIG. 4 is a sectional view of a main part of FIG. 2, showing a soldering state of a ground terminal and a metal terminal of the clip.

FIG. 5 is a perspective view of a clip according to the present invention.

FIG. 6 is a perspective view showing a conventional magnetic head for a floppy disk device.

FIG. 7 shows a conventional ground connection structure,
-V sectional drawing.

FIG. 8 shows another conventional ground connection structure.
VV sectional view of FIG.

FIG. 9 is a side view showing a state where a conventional magnetic head is soldered to a flexible wiring board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording / reproducing core part 2 Erase core part 3 Adhesive glass 4 Coil bobbin (Coil C1 is wound) 5 Coil bobbin (Coil C2 is wound) 6 Back core 7 Adhesive glass 8 Slider 10 Conventional clip 11 Gimbal 12 Flexible wiring board 13 Shield member 14 Mold glass 16 Clip of the present invention 17 Circuit pattern

Claims (3)

(57) [Claims] And 1. A front core forming a magnetic gap, and a back core in contact with the front core, and the metal terminals provided on a bobbin, and clips conductivity and said front core and a back core to press nip, no less And the slider that covers the back core and the circuit board on which the ground circuit is formed.
And a part of the clip is electrically connected to the ground circuit.
Ground conductive terminal is provided integrally, and the front end of the ground conductive terminal is bent to
The metal terminal is brought into contact with the ground conduction terminal and the metal terminal.
The contact portion of the metal terminal is projected outward from the slider.
And a magnetic head integrally connected to the ground circuit . 2. The ground conduction terminal has a middle letter.
And bent the tip of the ground conducting terminal to the
Pressed against the metal terminal by the elastic force of the clip
The magnetic head according to claim 1, wherein: 3. An earth connection between the ground conduction terminal and the circuit board.
The circuit is characterized by being connected by soldering
The magnetic head according to claim 1.