JPH054302U - Magnetic head device - Google Patents

Abstract

(57) [Summary] [Structure] The front core 4 of the magnetic head element including the front core 4, the back core 5, and the coil bobbins 6 and 7 around which the drive coil is wound is inserted through the empty terminal 25c of the erasing side coil bobbin 6. Solder connection is made with the grounding conductor pattern 40e of the printed wiring board. [Effect] The printed wiring board can be used in common regardless of the magnetic head device for 1 to 2 Mbytes and 4 Mbytes, and highly reliable grounding is possible.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a magnetic head device suitable for writing or reading an information signal on, for example, a floppy disk or the like.

[0002]

[Prior Art]

 Conventionally, as a magnetic head device for a floppy disk, one having a structure as shown in FIG. 7, for example, has been proposed. In this magnetic head device, a gimbal 52 is equipped with a magnetic head portion 51 formed by sandwiching a magnetic head element having a recording / reproducing magnetic gap and an erasing magnetic gap by a pair of sliders.

The magnetic head portion 51 has a front core 53 having a recording / reproducing magnetic gap and an erasing magnetic gap, a back core 54 having a substantially E-shaped cross section, a coil bobbin 57 around which a drive coil is wound, A magnetic head element including a magnetic circuit portion 58 is sandwiched by a pair of sliders 55 and 56 each having a substantially L-shaped cross section in order to secure contact characteristics with a floppy disk. The front core 53 and the back core 54 are superposed in a so-called stepped state in the coil bobbins 57 and 58 around which the drive coil is wound, and are pressed and supported by the core pressing member 59 so that they are magnetically coupled. It has become.

The magnetic head portion 51 configured as described above has a plurality of slits 61, 62 in a state of being fitted to a magnetic shield member 60 formed as a frame body having a substantially rectangular cross section. It is designed to be mounted on one surface of the provided gimbal 52. Then, the external terminals 63 and 64 provided on the coil bobbins 57 and 58 projecting from the slit 62 of the gimbal 52 to the other surface are electrically connected to the respective conductor patterns 66 of the printed wiring board 65. ing.

By the way, in the above-mentioned magnetic head device for a floppy disk, since an information signal is recorded / reproduced in a state where the floppy disk and the magnetic head are in contact with each other, static electricity is easily generated at the time of contact. Static electricity causes an error by overlapping with a recording / reproducing signal or as an extra pulse. Therefore, in this type of magnetic head device, the front core 53 is normally grounded on the drive circuit.

Specifically, as shown in FIG. 8, the notches 67, 68, 69 provided on the gimbal 52 extend over each leg of the front core 53 and a part of the notch 67, 68, 69, and the gimbal 52. A conductive paint 70 for electrical connection is applied, and the front core 53 and the gimbal 52 are electrically connected. Further, as shown in FIG. 9, the external terminals 63, 64 protruding from the slit 62 of the gimbal 52 and the lands 66a, 66b, ... 66e of the respective conductor patterns 66 of the printed wiring board 65 are connected by the solder 71. In addition to being electrically connected, conductive paint 73 is applied over the ground land portion 72a of the grounding conductor pattern 72 for grounding provided on the printed wiring board 65 and the gimbal 52, and these are electrically connected. As a result, the front core 53 is connected to the ground conductor pattern 72 of the printed wiring board 65 via the gimbal 52 and grounded on the drive circuit.

[0007]

[Problems to be solved by the device]

 By the way, in recent years, in order to further improve the recording density, a 4 Mbyte capacity has been developed in a 3.5-inch type floppy disk drive. In this 4 Mbyte floppy disk drive, the line recording density is 35 KBPI in order to increase the capacity, which is 4 times that of the conventional 1 Mbyte, and twice the 2 Mbytes, so the recording / reproducing gap is narrow at 0.4 μm, and it is 1-2 M The overwriting recording method (overwrite characteristics) used in the byte floppy disk drive cannot be used, and the preceding erase method is used to erase the track in advance during recording.

Therefore, in the 4 Mbyte magnetic head device, the recording / reproducing magnetic gap and the erasing magnetic gap are opposite to those of the 1 to 2 Mbyte magnetic head device. That is, in a magnetic head device of 1 to 2 Mbytes, as shown in FIG. 8, one external terminal 63 side serves as a recording / reproducing magnetic head and the other external terminal 64 side serves as an erasing magnetic head. On the contrary, in the bite magnetic head device, the recording / reproducing magnetic head side is the erasing magnetic head, and the erasing magnetic head side is the recording / reproducing magnetic head.

In addition, regardless of the magnetic head device for 1 to 2 Mbytes or 4 Mbytes, the earth land portion 72 a for grounding the front core 53 is generally located on either the recording / reproducing magnetic head side or the erasing magnetic head side. Since the printed wiring board 65 for 1 to 2 Mbytes is used for the magnetic head device of 4 Mbytes because it is fixed, not only the pattern shape of the conductor pattern 66 is changed but also the earth land portion 72a is reversed. Let's do it. Therefore, it is necessary to fabricate a new printed wiring board for 4 Mbytes.

However, in order to fabricate a new printed wiring board, a considerable amount of cost is required for pattern printing (original plate) and die cost, and the cost must be borne every time a 4 Mbyte model is made. I won't. Further, since the connection between the gimbal 52 and the ground conductor pattern 72 is made by the conductive paint 73, the reliability is low in terms of the joint strength. Therefore, the present invention has been proposed in view of such a conventional situation, and can be used as a printed wiring board regardless of the model, and enables highly reliable grounding in terms of bonding strength. An object is to provide a magnetic head device.

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, a magnetic head device of the present invention comprises a magnetic head portion including a magnetic core forming a closed magnetic path via a magnetic gap and a coil bobbin fitted and arranged in the magnetic core. And a gimbal provided with a printed wiring board on which the magnetic head unit is mounted, wherein the magnetic core is grounded to a grounding conductor pattern of the printed wiring board through an empty terminal of a coil bobbin. It is a thing.

[0012]

[Action]

 Generally, in a magnetic head device for a floppy disk, two coils are wound around a coil bobbin on the recording / reproducing side, and the winding start and end and the common part (common) of these two windings are arranged. Three terminals for taking out are provided. On the other hand, one coil is wound around the coil bobbin on the erasing side, and two terminals for extracting the winding start and winding end are provided. Normally, the recording / reproducing side and the erasing side coil bobbins are commonly used, and therefore the erasing side coil bobbin is also provided with three terminals. In the present invention, the empty terminal of the coil bobbin on the erasing side is used as a ground terminal.

That is, in the present invention, since the magnetic core is grounded to the grounding conductor pattern of the printed wiring board through the empty terminal of the coil bobbin, it is necessary to provide the grounding ground portion for grounding on the printed wiring board. Lost. Therefore, the orientation of the printed wiring board disappears, and the printed wiring board of the same shape can be used for the magnetic head device of 1 to 2 MB and 4 MB. Further, in the present invention, since the terminal and the conductor pattern are connected, the connection can be made by solder, and the joint strength of this portion is improved.

[0014]

【Example】

 Hereinafter, specific embodiments to which the present invention is applied will be described with reference to the drawings. The present embodiment is an example applied to a magnetic head device for a floppy disk that records and reproduces information signals on a floppy disk. In the magnetic head device of the present embodiment, as shown in FIG. 1, a magnetic head portion 1 constituted by sandwiching a magnetic head element having a recording / reproducing magnetic gap and an erasing magnetic gap by a pair of sliders has a printed wiring. It is mounted on a gimbal 3 provided with a substrate 2.

As shown in FIG. 2, the magnetic head unit 1 is fitted to the front core 4 and the back core 5, which are magnetic cores forming a closed magnetic circuit via a magnetic gap, and the front core 4 and the back core 5. A magnetic head element including coil bobbins 6 and 7 around which drive coils are wound together, a core pressing member 8 for magnetically coupling the front core 4 and the back core 5, and a contact with a floppy disk are secured. It is composed of a pair of sliders 9 and 10.

The front core 4 has substantially L-shaped side core portions on both sides of a pair of rod-shaped center core portions 12 and 13 joined together via a non-magnetic material 11 so as not to magnetically interfere with each other. 14 and 15 are butted against each other and have a _first magnetic gap g ₁ and a second magnetic gap g ₂ on the butted surface. The first magnetic gap g ₁ operates as a recording / reproducing magnetic gap, and the second magnetic gap g ₂ operates as an erasing magnetic gap.

On the other hand, in the back core 5, a pair of core members 16 and 17 formed corresponding to the core shape of the front core 4 are joined on the side surface side via the non-magnetic material 18. It is configured. The core members 16 and 17 have center leg portions 19 and 20 and side leg portions 21 and 22 at positions facing the center core portions 12 and 13 and the side core portions 14 and 15 of the front core 4, respectively, and are connected to each other. They are connected by members 23 and 24 and have a substantially U-shaped planar shape. Therefore, by providing the center leg portions 19 and 20 and the side leg portions 21 and 22, it becomes possible to secure a joint area between the cores that increases the length of the front core 4 in the depth direction, and the electromagnetic field is increased. The conversion characteristics can be improved.

The coil bobbins 6 and 7 are formed by insert molding the external terminals 25a, 25b, 25c and 26a, 26b, 26c formed by stamping a hoop material. The coil bobbin 6 through which the side core portion 14 of the front core 4 on the side where the erasing magnetic gap (the first magnetic gap g ₁ ) is formed is inserted with a predetermined number of one driving coil 27, and the winding is wound. The beginning and the end of winding are respectively wound around the external terminals 25a and 25b. On the other hand, the coil bobbin 7 into which the side core portion 15 of the front core 4 on the side where the recording / reproducing magnetic gap (the second magnetic gap g ₂ ) is formed is inserted is provided with two drive coils 28 in a predetermined number. The winding is performed, and the winding start, winding end, and common portion (common) are respectively wound around the three external terminals 26a, 26b, and 26c.

The front core 4 and the back core 5 are connected to the side core portions 14 and 15 of the front core 4 and the side leg portions 21 and 22 of the back core 5 in the through holes 6a and 7a of the coil bobbins 6 and 7, respectively. Come into contact with each other and are stacked in a so-called stacked state. That is, the one side surface 14a of the side core portion 14 and the one side surface 21a of the side leg portion 21 are in contact with each other, and the one side surface 15a of the side core portion 15 and the one side surface 22a of the side leg portion 22 are in contact with each other. The magnetic coupling is achieved to form a closed magnetic circuit. Therefore, by the front core 4, the back core 5, and the coil bobbins 6 and 7, the magnetic head element having the _first magnetic gap g ₁ that operates as the recording / reproducing magnetic gap, that is, the recording / reproducing head and the erasing magnetic gap. A magnetic head element having a _second magnetic gap g ₂ that operates as the above, that is, an erasing head is configured.

Further, in the through holes 6a, 7a of the coil bobbins 6, 7, a pair of core pressing pieces 29, 30 of the core pressing member 8 for magnetically coupling the front core 4 and the back core 5 is formed. Has been inserted. The core pressing member 8 is provided with a receiving portion 31 for a head pressing member (pivot) of a magnetic head supporting mechanism (not shown) provided on the back side of the magnetic head element, the side core portions 14 and 15 and the side leg portions 21 and 22. It consists of core pressing pieces 29, 30 inserted into the coil bobbins 6, 7.

The receiving portion 31 is provided in a substantially central portion of the connecting plate 32 having the receiving surface 31a of the pressing member so as to hang down in the contact direction of the pressing member, and serves as a support for the impact of the pressing member. There is. On the other hand, in the core pressing pieces 29 and 30, thin plate-like plates are hung in both ends along one side edge of the connecting plate 32 in the same direction as the receiving portion 31, and are integrally provided on the connecting plate 32. It has been done. The tip end portions of the core pressing pieces 29, 30 are formed in a substantially arc shape so that they can be easily inserted into the coil bobbins 6, 7 and workability can be improved. Since the core pressing member 7 plays a role of cushioning the impact from the head pressing member, it is preferable to mold the core pressing member 7 with a plastic having relatively plasticity such as polyacetal resin or ABS resin.

Further, on the surface of the core pressing pieces 29, 30 opposite to the surface facing the magnetic head element, that is, on the surface opposite to the surface facing the side leg portions 21, 22 of the back core 5, Semi-conical projections 33, 34 are formed to bring the front core 4 and the back core 5 into close contact with each other. Therefore, in the coil bobbins 6 and 7, the protrusions 33 and 34 provided on the core pressing pieces 29 and 30 come into contact with the inner wall surfaces of the coil bobbins 6 and 7 to move the core pressing pieces 29 and 30 to the back core. The core pressing pieces 29, 30 are elastically deformed to the 5 side and the side pressing portions 21, 22 of the back core 5 are pressed and supported by this elastic force. As a result, the side leg portions 21 and 22 of the back core 5 and the side core portions 14 and 15 of the front core 4 are in close contact with each other and pressed and supported, and the magnetic and mechanical between the front core 4 and the back core 5 is increased. The bond is secure. Therefore, no gap is created between the front core 4 and the back core 5, and the gap does not act as a back gap when the magnetic head is driven.

The magnetic head element having the above structure constitutes the magnetic head portion 1 by being sandwiched by the pair of sliders 9 and 10 for ensuring the contact characteristics with the floppy disk. That is, a pair of sliders having a substantially L-shaped cross section on both sides of the front core 4 on which the first magnetic gap g ₁ and the second magnetic gap g ₂ of the magnetic head element slide with the floppy disk. The magnetic head unit 1 is configured by providing the 9 and 10.

The magnetic head unit 1 configured as described above is mounted on one surface 3a of the gimbal 3 while being fitted to the magnetic shield member 35 formed as a frame body having a substantially rectangular cross section. It is supposed to be done. The gimbal 3 has a head mounting portion 36 on which the magnetic head portion 1 is mounted, and is notched so that the magnetic head portion 1 mounted on the head mounting portion 36 can be moved in the front-rear direction and the left-right direction against an impact or the like. It has a plurality of slits 37 and 38 formed therein. Further, the head mounting portion 36 is provided with notches 36a, 36b, 36c for exposing a part of the tip portions of the center core portions 12, 13 and the side core portions 14, 15 of the magnetic head element. Has been.

With respect to the gimbal 3 formed as described above, as shown in FIG. 3, the magnetic head portion 1 includes the tip portions 9a and 10a of the sliders 9 and 10 and the center core portion 12 of the front core 4 as shown in FIG. 13 and the side core portions 14 and 15 are provided so that the respective tip portions 12a, 13a, 14b and 15b thereof come into contact with the head mounting portion 36, and the magnetic force fitted to the outer periphery of the magnetic head portion 1 is fitted. The side wall of the shield portion 35 and the gimbal 3 are fixed by an adhesive material (not shown) applied. The external terminals 25a, 25b, 25c and 26a, 26b, 26c provided on the coil bobbins 6, 7 of the magnetic head unit 1 mounted on the gimbal 3 are provided by the slits 38, 38 facing the external terminals 25a, 25b, 25c and 26a, 26b. It projects toward the surface 3b opposite to the mounting surface of the portion 1. Further, the respective tip portions 12a, 13a and 14b, 15b of the center core portions 12, 13 and the side core portions 14, 15 of the front core 4 which come into contact with the head mounting portion 36 are provided at positions facing each other. Part of the cutout portions 36a, 36b, 36c faces.

The front cores 12 and 13 and the side cores 14 and 15 of the front core 4, which are partially exposed by the cutouts 36a, 36b, and 36c, respectively, have their front ends 12a, 13a and 14b, 15b. A conductive paint 39a is applied over the gimbal 3 to electrically connect to the gimbal 3. Further, conductive paint 39b is applied over the gimbal 3 to the empty terminal 25c provided on the coil bobbin 6 through which the side core portion 14 of the front core 4 provided with the erasing magnetic gap and the side leg portion 21 of the back core 5 are inserted. Similarly, the connection with the gimbal 3 is made electrically. Therefore, the front core 4 is electrically connected to the vacant terminal 25c via the gimbal 3.

The external terminals 25a, 25b, 25c, 26a, 26b, 26c of the magnetic head unit 1 mounted on the gimbal 3 have conductor patterns corresponding to those of the printed wiring board 2 shown in FIG. The through holes 40a, 40b, 40c, 40d and 40e are inserted into the through holes, and solder 41 is attached as shown in FIG. 5 for electrical connection. Specifically, the external terminal 26a of the coil bobbin 7 on the recording / reproducing side is connected to the conductor pattern 40c, the external terminal 26b is connected to the conductor pattern 40b, and the external terminal 26c is connected to the conductor pattern 40a. On the other hand, the external terminal 25a of the erase-side coil bobbin 6 is connected to the conductor pattern 40c, the external terminal 25b is connected to the conductor pattern 40d, and the empty terminal 25c is connected to the conductor pattern 40e. The conductor pattern 40e connected to the empty terminal 25c is a conductor pattern for grounding that is grounded on the drive circuit. Therefore, the front core 4 is electrically connected to the grounding conductor pattern 40e of the printed wiring board 2 through the vacant terminal 25c, and is grounded on the drive circuit.

In this way, if the grounding of the front core 4 is electrically connected to the grounding conductor pattern 40e of the printed wiring board 2 via the vacant terminal 25c of the coil bobbin 6, the grounding land for the grounding is purposely provided. It is no longer necessary, and the land portion of the grounding conductor pattern 40e can have the same shape as the land portion connected to a normal external terminal. Therefore, the printed wiring board 2 has no directionality, and the printed wiring board 2 having the same shape can be applied to a magnetic head device of 1 to 2 MB and 4 MB. That is, in the magnetic head device of 1 to 2 Mbytes and the magnetic head device of 4 Mbytes, the recording / reproducing magnetic head and the erasing magnetic head are reversed, but in both cases, the erasing terminal is an empty terminal for grounding. Since this is an empty terminal of the coil bobbin on the side, the printed wiring board 2 can be shared by connecting the grounding conductor pattern 40e to this empty terminal. Further, since the vacant terminal 25c and the grounding conductor pattern 40e are connected by the solder 41, the bonding strength of this portion is increased and the reliability is improved.

To manufacture the magnetic head device having the above structure, first, the magnetic head unit 1 is manufactured. That is, the coil bobbins 6 and 7 are fitted into the side core portions 14 and 15 of the front core 4, respectively, and then the side leg portions 21 and 22 of the back core 5 are inserted into the coil bobbins 6 and 7. Then, after the core pressing pieces 29, 30 of the core pressing member 8 are inserted into the coil bobbins 6, 7 by pressing, the sliders 9, 10 are adhesively fixed to both sides of the front core 4. Then, the magnetic shield member 35 is fitted into the magnetic head portion 1 so as to surround the outer circumferences of the sliders 9 and 10, and is mounted on the gimbal 3 in this state and fixed with an adhesive.

Next, the conductive paints 39 a and 39 b are applied over the gimbal 3 and the tip of the front core 4 that contacts the gimbal 3, and over the empty terminal 25 c of the erasing coil bobbin 6 and the gimbal 3. The conductive paint 39b for connecting the vacant terminal 25c and the gimbal 3 can be applied in the same step for electrically connecting the front core 4 and the gimbal 3, so that it is a separate step as in the conventional case. The complexity of doing is eliminated.

Next, the external terminals 25a, 25b, 25c, 36a, 36b, 36c are soldered to the respective conductor patterns 40a, 40b, 40c, 40d, 40e of the printed wiring board 2 for electrical connection. Try. The connection between the vacant terminal 25c and the conductor pattern 40e may be applied with a conductive adhesive or a conductive paint, although the bonding strength is slightly inferior to the connection with the solder 41. As a result, the front core 4 is connected to the grounding conductor pattern 40e through the vacant terminal 25c and grounded on the drive circuit.

Although an example of the magnetic head device to which the present invention is applied has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made. In the above example, the front core 4 is grounded, but the same effect can be obtained even if the back core 5 is grounded. In addition to this, as shown in FIG. 6, the facing portion of the gimbal 3 corresponding to the land portion of the grounding conductor pattern 40e is projected, and the conductive paint 42 is applied to this portion to electrically connect with the grounding conductor pattern 40e. You may connect it to. In this case, it is necessary to remove the empty terminal 25c provided on the erasing side coil bobbin 6.

[0033]

[Effect of the device]

 As is apparent from the above description, according to the present invention, the magnetic core is electrically connected to the grounding conductor pattern of the printed wiring board through the empty terminal of the coil bobbin so as to be grounded. There is no need to provide a separate ground land for the printed wiring board, and the orientation of the printed wiring board is lost. Therefore, a printed wiring board having the same shape can be applied to any of the magnetic head devices for 1 to 2 Mbytes and 4 Mbytes, and the printed wiring board can be shared.

As a result, it is not necessary to newly prepare an original plate or a mold for pattern wiring for manufacturing a printed wiring board, and it is expected that a die cost or the like can be significantly reduced. Further, in the magnetic head device of the present invention, the connection between the vacant terminal and the printed wiring board is soldered, so that the reliability is further improved in terms of bonding strength.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an example of a magnetic head device to which the present invention is applied.

FIG. 2 is an exploded perspective view of a magnetic head unit.

FIG. 3 is a perspective view showing a state in which a magnetic head unit is mounted on a gimbal.

FIG. 4 is a perspective view showing a state in which a printed wiring board is attached to external terminals of a magnetic head unit.

FIG. 5 is a perspective view showing a state in which a conductor pattern of a printed wiring board is solder-connected to an external terminal of the magnetic head unit.

FIG. 6 is a diagram showing another example of grounding the front core.

FIG. 7 is an exploded perspective view showing an example of a conventional magnetic head device.

FIG. 8 is a perspective view showing a state in which a magnetic head portion of a conventional magnetic head device is mounted on a gimbal.

FIG. 9 is a perspective view showing a state in which a printed wiring board is attached to a magnetic head portion of a conventional magnetic head device.

[Explanation of symbols]

 1 ... Magnetic head part 2 ... Printed wiring board 3 ... Gimbal 6, 7 ... Coil bobbin 25c ... Empty terminal 40e ... Grounding conductor pattern

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Hideko Matsumoto 6-5-6 Kitashinagawa, Shinagawa-ku, Tokyo Sony Magne Products Co., Ltd.

Claims (1)

Claims for utility model registration: 1. A magnetic head part comprising: a magnetic core forming a closed magnetic path via a magnetic gap; and a coil bobbin fitted and arranged in the magnetic core; and the magnetic head part. A magnetic head device, comprising: a gimbal provided with a printed wiring board to be mounted; wherein the magnetic core is grounded to a grounding conductor pattern of the printed wiring board through an empty terminal of a coil bobbin.