JPH11250418A - Case for thin film magnetic head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of and damage to a thin film element caused by the discharging current at the time the conductive part of a wiring material is brought into contact with the inside surface of a case in a state in which static electricity is charged on the insulator part of the wiring material by forming the case holding thin film magnetic head devices with material whose surface resistance is within a specific range. SOLUTION: A thin film magnetic head device H is constituted of a load beam 1, a slider 4 on which a thin film element is mounted and a wiring material C. The wiring material C is provided with conductive leads 7 connected with the thin film element and a coating insulator 8. After the electric characteristics and the magnetic characteristics of the thin film element are inspected and measured, the thin film magnetic devices H are housed in a case 20 in the unit of the stipulated number of devices and they are transported to the manufacturing place of the main body of a hard disk device or the like. There is a case sometime in which the insulator 8 is charged in the manufacturing process of thin film magnetic head device H. Then, the case is formed with the ion conductive body of, for example, zirconia ceramics or the like and the surface resistance of the material is set to be within the range of 1×10<6> to 1×10<12> Ω/(square).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case for holding a magnetic head device on which a thin film element is mounted, and in particular, to prevent deterioration or breakage of the thin film element due to electrostatic charging of an insulator portion of a wiring member. The present invention relates to a case for a thin film magnetic head device.

[0002]

2. Description of the Related Art FIG. 8 is a perspective view of a thin-film magnetic head device installed in a hard disk device or the like. In this magnetic head device, a flexure 3 which is also an elastic support member is attached to a front end of a load beam 1 which is an elastic support member.
A ceramic slider 4 is mounted on the flexure 3. The slider 4 is supported so as to be able to change its attitude with respect to the load beam 1 via a pivot. A mount plate 2 is joined to the base end of the load beam 1.

A thin film element 5 is mounted on an end of the slider 4 on the trailing side. The thin-film element 5 includes a reproducing unit having an MR element for detecting a leakage magnetic field from a recording medium such as a hard disk using a magnetoresistance effect, and an inductive thin-film head having a coil pattern and recording a magnetic signal on the recording medium. Recording section.

A conductive lead 7 is connected to the electrode pad of the thin-film element 5, and the conductive lead 7 is covered with an insulator 8 to form a wiring material. The wiring member has a portion covered with the insulator 8 fixed to the edge of the load beam 1 and extends from the base end of the load beam 1. A paddle 9 is connected to the conductive lead 7 at the base end of the wiring member. The paddle 9 is made of an insulating material such as glass epoxy, and has lands 9a, 9b, 9c, 9d made of a conductive material on the surface thereof, and each lead wire 7a, 7b, 7c, 7c of the conductive lead 7 is formed.
7d is soldered and connected to each of the lands 9a, 9b, 9c, 9d.

In this magnetic head device, a paddle 9 is used as a wiring material.
Are connected, the land portions 9a, 9b,
The DC resistance of the thin film element 5 is measured through 9c and 9d,
Alternatively, other electrical or magnetic properties are inspected or measured. Then, the conductive leads 7a, 7b,
The paddles 9c and 7d are cut to separate the paddle 9 from the wiring material, and a plurality of magnetic head devices after the paddle 9 is separated are housed in a case and moved to a manufacturing location of a device main body such as a hard disk device. Transported. Then, at this manufacturing location, the magnetic head device taken out of the case is assembled into a hard disk device or the like.

Alternatively, the magnetic head device is housed in a case with the paddle 9 connected thereto and transported to a manufacturing place such as a hard disk drive, where the land portion 9a, 9b, 9c, 9d is connected. The electrical characteristics and magnetic characteristics are inspected and measured, and immediately thereafter, the conductive leads 7a, 7b, 7c, 7d are cut to separate the paddle 9, and incorporated into a hard disk device or the like. Conventionally, the case is formed of a carbon-based polymer material such as polycarbonate. The reason why polycarbonate or the like is used as the material forming the case is that polycarbonate or the like is unlikely to be charged by static electricity.

[0007]

In the manufacturing process of the magnetic head device described above, the relationship between the temperature and humidity in the working environment and the frictional force applied to the wiring member during the work are determined.
Although static electricity is easily charged on the insulating insulator 8 of the wiring material, if the magnetic head device is held in a case made of polycarbonate or the like while the insulator 8 is charged, the thin-film element 5 may be charged due to the static electricity. It has been discovered that migration between layers occurs, thereby deteriorating the reproduction characteristics and the like of the magnetic head, and furthermore, the thin film element H, particularly the MR element, undergoes melt fracture.

[0008] This phenomenon can be explained with reference to FIG. When the insulator is charged with static electricity due to friction or the like, electrostatic polarization occurs in the internal conductive leads. For example, when a positive charge due to static electricity is charged on an insulator, a positive charge is concentrated at the center in the conductive lead, and a negative charge is concentrated at a boundary with the insulator, that is, electrons in the conductive lead are Concentrated on the boundary with the insulator, the inside of the conductive lead is polarized and brought into an equilibrium state. When the conductive lead contacts the low-resistance conductive material while the insulator is charged in this way, in the case of FIG. 6, electrons of the conductive material rapidly flow into the center of the conductive lead, and As a result, an excessive current flows through the thin film element. When an excessive current flows in the layer of the MR element of the thin film element 5, the MR element generates heat due to Joule heat, and the heat is not dissipated, so that migration between layers of the MR element or melting destruction occurs.

Here, since the surface resistance (Ω / square) of the carbon-based polymer material such as polycarbonate which constitutes the conventional case is of the order of 10 ² , it is not an insulating material for static electricity. Also has properties as a conductive material. Therefore, the conductive leads 7a, 7b, 7c, 7 after the paddle 9 is cut when the magnetic head device is held and housed in the case.
When d contacts the inner surface of the case, or when the magnetic head device is stored and held in the case while the paddle 9 is connected, the land portions 9a, 9
When b, 9c, and 9d come into contact with the inner surface of the case, FIG.
As shown in (1), electrons rapidly move between the center of the conductive lead that is electrostatically polarized and polycarbonate or the like. As a result, an excessive current flows through the thin film element 5, particularly the MR element, and there is a possibility that migration between the above-mentioned layers and melting destruction of the MR element may occur.

FIGS. 7A and 7B compare the passing current based on static electricity between an iron-based metal material and polycarbonate. In this experiment, with the charge plate charged to 100 V, one of the grounded iron-based metal materials was brought into contact with the charge plate, and the other with the grounded polycarbonate in contact with the charge plate. The current flowing to the side was measured by an oscilloscope. FIG. 7A shows a case where an iron-based metal material is used.
B is the case where polycarbonate was used.

As shown in FIG. 7A, when an iron-based metal material is brought into contact with the charge plate, a current of 300 mA or more instantaneously flows to the ground side through the iron-based metal material,
The current of A or more continues until about 5 nsec. Also,
As shown in FIG. 7B, even when the polycarbonate is brought into contact with the charge plate, a current of 200 mA or more instantaneously flows to the ground side through the polycarbonate, and furthermore, 2 n
The current continues to flow for about sec. Thus, it is understood that polycarbonate almost acts as a conductive material against static electricity. Therefore, when the magnetic head device is held in a polycarbonate case, when the conductive lead contacts the case in a state where the insulator is charged, and when the conductive material contacts the conductive lead. Almost the same large current flows, and there is a possibility that migration between layers due to Joule heat may occur in the MR element or melting and destruction may occur.

The present invention has been made to solve the above-mentioned conventional problems, and when a conductive portion of a wiring member comes into contact with an inner surface of a case, the thin-film element is prevented from being deteriorated or damaged due to static electricity. An object is to provide a case for a head device.

[0013]

According to the present invention, there is provided a case for a thin film magnetic head device, wherein a slider on which a thin film element is mounted is attached to an elastic support member, and the conductive lead is electrically connected to the thin film element. In a case for holding a thin-film magnetic head device provided with a wiring member made of an insulator covering the surface of the substrate, at least a region in contact with the conductive lead or a region in contact with a portion conductive with the conductive lead has a surface resistance. Is formed of a semiconductive material of 1 × 10 ⁶ Ω / square or more and less than 1 × 10 ¹² Ω / square.

The case according to the present invention can be separated vertically into two so as to hold the magnetic head device.
The whole of both the upper half and the lower half separated from each other is formed of the semiconductive material. Or, inside the case, only the area that contacts the conductive lead of the wiring material, or the paddle attached to the wiring material, or the area where the land part of the paddle part formed on the wiring material formed on the flexible printed circuit board contacts May be formed of a semiconductive material, and the other portions may be formed of polycarbonate or the like.

[0015] In the above, the wiring material may be a conductive lead formed of a wire material covered with an insulator, or a flexible printed board in which the conductive leads are formed on the insulating film as described above. is there. In the case of a flexible printed board, the resist film covering the insulating film and the conductive leads serves as an insulator charged with electrostatic charges. When the flexible printed board is a wiring material, the land is formed on a paddle portion at the base end of the flexible printed board.

In the case, if a region to which a conductive lead or the like may come in contact is formed of a semiconductive material, the conductive lead is placed in a state where the insulator of the wiring member is charged. When contacted with the conductive lead,
Electrons flow at a slow speed between the semiconductive material constituting the case and the equilibrium state of the electrostatic polarization in the conductive lead is eliminated, but at this time, the current flowing through the thin film element becomes small,
Deterioration of the thin film element and electrostatic breakdown can be prevented.

For example, the semiconductive material is an ionic conductive ceramic, an ionic conductive polymer, or a composite conductive material in which a conductive filler is mixed in a polymer.

[0018]

FIG. 1 is an overall perspective view of a case for a thin film magnetic head device according to the present invention, and FIG. 2 is a partial perspective view showing an example of the internal structure of the case. The basic configuration of the magnetic head device H shown in FIGS. 1 and 2 is the same as that shown in FIG. In the magnetic head device H, a flexure is provided at the tip of the load beam 1, and a slider 4 is joined to the flexure. The load beam 1 and the flexure are elastic support members formed of a leaf spring or the like. A mount plate 2 is joined to the base end of the load beam 1.

As shown in FIG. 4, the slider 4 has a leading side on the α side and a trailing side on the β side, and a recording medium such as a hard disk travels from the leading side to the trailing side. Rail-shaped ABS surfaces 4a, 4a are formed on a surface of the slider 4 facing the recording medium, which receives a levitation force due to an air flow on the recording medium, and a thin film element 5 is provided on an end surface 4b on the trailing side. I have.

FIG. 5 shows the reproducing section of the thin film element 5 as the ABS 4
It is sectional drawing seen from a side. The thin-film element 5 includes a reproducing unit using the magnetoresistance effect shown in FIG. 5 and a recording unit provided so as to overlap the reproducing unit. The reproducing section of the thin film element 5 shown in FIG.
From the side b, a lower shield layer 11 and a lower gap layer 12 as an insulating layer are sequentially formed, an MR element 13 is stacked thereon, and an upper gap layer 14 and an upper shield layer 15 as insulating layers are further stacked. Is formed. MR layer 1
Reference numeral 3 denotes a three-layer structure of SAL, SHANT, and MR, and a hard bias layer 16 and a conductive layer 17 are formed on both sides thereof. Alternatively, as for the MR element, a hard bias layer 16 and a conductive layer are formed on both sides of the element similarly in a spin valve element and a dual spin valve element.

In the thin film element 5, an inductive recording section having a coil layer, an upper core layer and the like is formed on the reproducing section shown in FIG. As shown in FIG. 4, on the trailing end surface 4b of the slider 4, the conductive layer 17 and the electrode pad 6 electrically connected to the coil layer of the recording section are formed.

The magnetic head device H is provided with a wiring member C. The wiring material C is made of a wire such as a conductive wire.
The conductive leads 7 are covered with an insulator 8 such as a resin material. One end of the conductive lead 7 is connected to each electrode pad 6 of the slider 4 shown in FIG. 4 by soldering or the like, and the other end of the conductive lead 7 is connected to a land 9 on the paddle 9.
a, 9b, 9c, 9d. The paddle 9 shown in FIG. 8 is for inspection / measurement, is formed of an insulating material, and the lands 9a, 9b, 9c, 9d are formed of copper foil or the like. When the magnetic head device H is stored in the case 20 shown in FIGS. 1 and 2, the lands 9a, 9b,
The inspection / measurement using 9c and 9d has been completed, and the conductive lead 7 has been cut and the paddle 9 has been removed.

However, as shown in FIG. 8, the magnetic head device H may be housed in the case 20 together with the paddle 9 in a state where the paddle 9 is connected to the wiring member C. As shown in FIG. 1, the case 20 includes an upper half 21 and a lower half 22, and the upper half 21 and the lower half 22 can be combined and separated from each other.

As shown in FIG. 2, the lower half 2 of the case 20
2, a holding rib 23 is integrally formed, and the holding rib 23 is integrally formed with a groove 23a and a support pin 23b. Similarly, a holding rib 24 is formed on the lower surface of the upper half 21 facing the holding rib 23, and a groove 24a is also formed in the holding rib 24. At the base end of the load beam 1 of the magnetic head device H, a support hole 1a communicating with the mount plate 2 is opened.
This support hole 1a is inserted through the portion. When the upper half portion 21 and the lower half portion 22 are combined, the portion of the mounting plate 2 becomes the groove 23a of the holding rib 23 and the groove 24a of the holding rib 24.
And sandwiched between.

Further, another holding rib 25 is formed in the lower half portion 22, and a groove 25a is formed in the holding rib 25. A holding rib 26 is formed on the lower surface of the upper half 21 opposed to the holding rib 25.
a is formed. When the upper half 21 and the lower half 22 are combined, the groove 25a and the groove 26a hold the base end of the load beam 1 at a position slightly closer to the base end than the part where the slider 7 is joined. . A plurality of holding structures shown in FIG. 2 are formed in the case 20, and a plurality of magnetic head devices H can be housed and held in the case 20, as shown in FIG. .

The entire upper half 21 and lower half 22 of the case 20 are formed of a semiconductive material. In this specification, the surface resistance is 1 × 10 ⁶ Ω / square.
A material that is equal to or more than re and less than 1 × 10 ¹² Ω / square is defined as a semiconductive material. The surface resistance is 1 × 10 ⁶ Ω /
A material less than square is a conductive material and the surface resistance is 1 ×
A material of 10 ¹² Ω / square or more is defined as an insulating material.

Here, the surface resistance is 1 × 10 ⁶ Ω / squ.
The semiconductive material having an area of not less than 1 × 10 ¹² Ω / square is an ionic conductor, for example, an ion conductive ceramic such as zirconia ceramic or β-alumina ceramic, or an ion such as polyacetylene or poly-p-phenylenevinylene. The conductive polymer is a composite conductive material in which a conductive filler such as carbon or metal powder is mixed in the polymer. The case 20 is formed of these materials. Even if the entire case 20 is not formed of a semiconductive material, for example, only the rib 27 of the lower half 22 and the rib 28 of the upper half 21 are formed of the semiconductive material,
The conductive leads 7 exposed from the insulator 8 may be held by the ribs 27 and 28, and a portion other than the ribs 27 and 28 may be formed of polycarbonate or the like.

As shown in FIG. 6, the humidity in the working environment,
When the insulator 8 is charged with static electricity due to the temperature and the friction given to the wiring member C, the electrons are biased inside the conductive lead 7 and dielectric polarization occurs to be in an equilibrium state. When the conductive lead 7 is electrically connected to the conductive material when excessive dielectric polarization occurs, electrons rapidly move between the conductive material and the conductive lead, and the thin film element 5, particularly the MR element, Excess current flows through the layer 13, causing migration between layers due to Joule heat, and furthermore, melting and destruction of the MR element 13. In the present invention, since a portion (region) to which the conductive lead 7 may come into contact in the case 20 is formed of a semiconductive material, when the conductive lead 7 comes into contact with the inner surface of the case 20. A current gradually flows between the conductive lead 7 and the semiconductive material forming the case 20. Thereby, the equilibrium state of the dielectric polarization in the conductive lead 7 as shown in FIG. 6 is relaxed or eliminated. At this time, the current flowing from the conductive lead 7 to the MR element 13 via the conductive layer 17 shown in FIG.
Can be suppressed, and the occurrence of the migration and the melt fracture can be prevented.

When the case 20 is made of an insulating material, when the conductive leads 7 come into contact with each other, electrons do not move between the conductive leads 7 and the insulating material.
Cannot be relaxed or eliminated. In addition, since the insulating material itself is easily charged, the charging of the insulator 8 is further promoted in the case, and the dielectric polarization in the conductive lead 7 is easily promoted.

FIG. 3 shows another configuration example of the thin-film magnetic head device. In this magnetic head device Ha, the wiring material Ca
Are constituted by the flexible printed circuit board F.
In the flexible printed board F, conductive leads are pattern-formed on the surface of an insulating film, and the surface is covered with a resist. A paddle portion Fa is integrally formed at the base end.
Land portions 9a, 9b, 9c, 9d made of conductive material
Are exposed, and the lands are electrically connected to the thin film element 5 through the respective conductive leads.

The paddle portion Fa is used for inspection and measurement like the paddle 9, and is provided between the magnetic head and the device main body in a state mounted on a hard disk device or the like before the paddle portion Fa. Are provided with connection lands 33a, 33b, 33c, 33d for transmitting the signals. After the magnetic head device Ha is manufactured and the inspection / measurement of the thin film element 5 is completed via the land portions 9a, 9b, 9c, 9d of the paddle portion Fa, the flexible printed circuit board F
Is cut at the line L to remove the paddle portion Fa.

When the magnetic head device Ha is housed and held in the case 20 of the present invention with the paddle portion Fa removed, the connection lands 33a, 33b, 33 are provided.
Even if c and 33d make contact with the inner surface of the case, electrostatic breakdown of the thin film element can be prevented. Further, even if the lands 9a, 9b, 9c, and 9d come in contact with the inner surface of the case 20 when the paddle portion Fa is held in the case 20 without being cut, the electrostatic breakdown can be similarly prevented. . The magnetic head device of the present invention is not limited to a hard disk, but may be used for detecting magnetism from another magnetic recording medium or as other various magnetic sensors.

[0033]

As described above, when the thin-film magnetic head device case of the present invention is used, the region where the conductive leads come into contact is formed of a semiconductive material. This can effectively prevent migration between layers of the thin film element and melting and destruction.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a thin film magnetic head case of the present invention;

FIG. 2 is a partial perspective view showing an example of an internal structure of a case;

FIG. 3 is a perspective view showing another configuration example of the thin-film magnetic head device;

FIG. 4 is a perspective view showing a slider with a surface facing a recording medium facing upward;

FIG. 5 is a cross-sectional view of the reproducing section of the thin-film element viewed from the ABS side.

FIG. 6 is an explanatory diagram of dielectric polarization of a conductive lead,

FIG. 7 is a diagram illustrating the flow of current due to static electricity, where A is the case where a metal material contacts a charge plate;
B shows the case where the polycarbonate came into contact with the charge plate.

FIG. 8 is a perspective view showing a magnetic head device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Load beam 2 Mount plate 3 Flexure 4 Slider 5 Thin film element 7 Conductive lead 8 Insulator 9 Paddle 9a, 9b, 9c, 9d Land part 13 MR element 20 Case 21 Upper half 22 Lower half C, Ca Wiring material F Flexible printed circuit board Fa paddle section H, Ha Thin film magnetic head device

Claims (5)

[Claims] 1. A thin film in which a slider on which a thin film element is mounted is attached to an elastic support member, and a wiring member comprising a conductive lead electrically connected to the thin film element and an insulator covering the conductive lead is provided. In the case of holding the magnetic head device, at least a region in contact with the conductive lead or a region in contact with the conductive lead has a surface resistance of 1 × 10 ⁶ Ω / square or more and 1 × 10 ¹² Ω. A case for a thin-film magnetic head device, wherein the case is formed of a semiconductive material less than / square. 2. The semiconductor device according to claim 1, wherein the magnetic head device is vertically separable into two parts so that the magnetic head device can be sandwiched between the upper and lower halves. The case for a thin film magnetic head device according to claim 1, wherein 3. The thin-film magnetic head device case according to claim 1, wherein the semiconductive material is an ionic conductive ceramic. 4. The thin-film magnetic head device case according to claim 1, wherein the semiconductive material is an ionic conductive polymer. 5. The thin-film magnetic head device case according to claim 1, wherein the semiconductive material is a composite conductive material in which a conductive filler is mixed in a polymer.