JPH10233011A - Sensor type thin film magnetic head and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent electrostatic destruction of a magneto-resistance sensor element (MR element) by arranging a slider fixedly with the MR element connected between one lead or pad and the other lead or pad and a resistor arranged in parallel. SOLUTION: The leads 38 and 40 are connected to both end parts of the MR element 36, and the pads 60 and 62 are connected to end parts of the leads 38 and 40 respectively. The resistor 74 is connected between the pads 60 and 62. The resistor 74 is formed of the same material as the MR element 36. At the time of forming the MR element 36, this is formed to be connected with the end parts of the leads 38 and 40 at the same time. The resistor 74 is formed in a kudzu-like folding pattern. Consequently, when one pad is charged with static electricity, an electric charge is distributed through the resistor 74 to the other pad to prevent generation of a large potential difference between both ends of the pads 60 and 62, so as to prevent electrostatic destruction of the MR element 36. A resistance value of the resistor 74 is set to a desired value by the number of folding times of the kudzu-like folding pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a magnetoresistive sensor element (hereinafter simply referred to as "sensor element") whose resistance value changes by magnetism such as an MR (magnetoresistive) effect and a GMR (giant magnetoresistance) effect. In the magnetic head, the electrostatic breakdown of the sensor element is prevented.

[0002]

2. Description of the Related Art An MR element and a GMR element are elements whose resistance changes due to magnetism, and are incorporated in a slider of a magnetic head in a magnetic disk device such as a hard disk device and used as a read-only element. A conventional sensor type thin film magnetic head using an MR element or a GMR element has a slider in which a sensor element, a lead for supplying a sense current to the sensor section, and a pad for connecting a lead end to an external wiring are fixedly arranged. It is configured to be installed.

[0003]

In general, a thin-film magnetic head has a plurality of sensor elements, leads, and pads constituting a plurality of magnetic heads formed on a single substrate in a vertical direction and a horizontal direction. A row in which a plurality of magnetic heads were arranged in a line was formed by cutting into a strip shape, and the sensor element on the row was ground and polished to a predetermined size to form a rail surface, and a protective film and the like were covered thereon. Later, it is made by cutting the row into individual sliders.

In this manufacturing process, there are many occasions where static electricity is applied to the pads. For example, in a processing step of finishing the tip portion of the sensor element into a predetermined shape, when the surface is cleaned or a protective film is formed, a step such as ion cleaning is passed. At this time, the pad may be charged by collision of charged plasma. In addition, the pad may be charged with static electricity by coming into contact with a person or a surrounding triboelectrically charged substance after being divided into individual sliders or approaching a CRT display operating at a high pressure. When one of the pads is charged with static electricity, a large potential difference is generated between the two pads, and a large charge moves through the sensor element (current flows).

The size of the sensor element of the sensor type thin film magnetic head is as small as 1 to 5 μm in the vertical and horizontal directions, and the thickness is 10 nm or less. On the other hand, the lead extending from the sensor element and the pad constituting the lead end have a thickness of several μm.
And the area is [100 μm to 300 μm] × [30 μm to 2
00 μm]. For this reason, when a large current flows due to the charge transfer, the current density of the sensor element is increased, and the sensor element may be damaged or the sensor element may be degraded due to migration (increase in resistance).

SUMMARY OF THE INVENTION An object of the present invention is to provide a sensor type thin film magnetic head which solves the above-mentioned problems in the prior art and prevents electrostatic breakdown of a sensor element, and a method of manufacturing the same.

[0007]

According to the present invention, there is provided a sensor type thin film magnetic head comprising a slider connected between one lead or pad and the other lead or pad and arranged in parallel with a sensor element on a slider. It is fixedly arranged. According to this, when one pad is charged,
Electric charges are distributed to the other pad through the resistor, so that a large potential difference is prevented from being generated between both ends of the pad, and electrostatic damage of the sensor element is prevented.

In the method of manufacturing a sensor-type thin-film magnetic head according to the present invention, the resistor is formed of the same material as the sensor element, and is formed simultaneously when the sensor element is formed. According to this, the number of steps can be reduced as compared with the case where a resistor is externally connected later, and manufacturing is easy. Further, since the resistor is added at a stage before the substrate is cut, it is possible to prevent electrostatic breakdown in a subsequent processing step.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sensor type thin film magnetic head according to the present invention will be described below. Here, a case where the present invention is applied to an MR / inductive composite thin film magnetic head for a hard disk will be described. FIG. 2A shows the entire structure. The MR / inductive type thin-film magnetic head 10 is adhesively fixed to the tip of a suspension 12. The magnetic head 10 has a main body formed of a slider 14. A center rail 16 and a side rail 1 are provided on the magnetic recording medium facing surface 14a of the slider 14 as a rail pattern.
8, 20 and a cross rail 22 are formed. The side rails 18, 20 and the cross roll 22 are connected on the air inflow end side. Air outflow end surface 14 of slider 14
The magnetic head unit 24 is provided in b.

As shown in FIG. 2 (b), the magnetic head section 24 has an MR type thin film magnetic head section 26 dedicated to reproduction and an inductive type thin film magnetic head section 28 dedicated to recording on an insulating film 72. They are arranged in layers. The MR thin-film magnetic head 26 includes an MR film 3 as shown in an enlarged view in FIG.
0, a spacer film 32, and an MR element (magnetoresistive sensor element) 36 in which a SAL bias film 34 is laminated, and leads 38 and 40 connected to both ends thereof. The lead 40 is formed by laminating a longitudinal bias magnet film 42 and a conductive film 44. Opposing surfaces 38a, 4 of the left and right leads 38, 40
0a is formed on an inclined surface, and both ends of the MR element 36 are connected to the leads 38, 40 at the inclined surfaces 38a, 40a. Before and after the MR element 36 and the leads 38 and 40, a lower shield film 46 and an upper shield film 48 are disposed with an alumina film 80 and 82 constituting a reproducing gap interposed therebetween, thereby forming a shield type MR head. .

A coil and an insulating layer 52 are formed on the MR thin-film magnetic head section 26 with an alumina film 50 constituting a write gap therebetween, and an upper core 54 is provided thereon to form an inductive thin-film magnetic head. The head unit 28 is constituted. The upper shield film 4 of the MR type thin film magnetic head section 26
Reference numeral 8 also serves as a lower core of the inductive type thin film magnetic head unit 28.

On the alumina film 50, metal pads 58, 60, 62, 64 for connecting to the external wiring 56 are formed.
Are arranged. The pads 60 and 62 penetrate the alumina films 50 and 82 and pass through the MR thin-film magnetic head 26.
Are connected to the ends of the leads 38 and 40. The pads 58 and 64 are connected to the coil of the inductive thin-film magnetic head unit 28 and the coil terminals of the insulating layer 52 via leads 66 and 68 wired on the alumina film 50.
The alumina protective film 70 is covered on the alumina film 50 to cover the entire magnetic head 24. Pads 58 and 6
The upper surfaces of 0, 62 and 64 are exposed on the surface of the protective film 70,
Bonding pad portions 58a, 60 for external wiring 56
a, 62a and 64a. Lower shield film 46, alumina films 80, 82, 50 for read gap, MR element 3
6, leads 38, 40, upper shield film 48, upper core 54
Is exposed on the rail surface near the rear end of the center rail 16.

FIG. 1 shows the structure of the main part of the MR type thin film magnetic head section 26. Leads 3 are provided at both ends of the MR element 36.
8 and 40 are connected, and pads 60 and 62 are connected to the ends of the leads 38 and 40, respectively. Also, pads 60 and 6
A resistor 74 is connected between the two. The resistor 74 is M
It is made of the same material as the R element 36 and is formed so as to connect the ends of the leads 38 and 40 at the same time when the MR element 36 is formed. The resistor 74 is formed in a zigzag shape.

If the line width (cross-sectional area) of the resistor 74 is smaller than the line width of the MR element 36, when electric charges accumulate in one of the pads 60 and 62, the resistance is reduced in order to reduce the potential difference between the pads 60 and 62. When a current flows through the body 74, the resistor 74 may be damaged, and the protection function may be performed in an electrostatic application environment due to subsequent ion cleaning for surface cleaning or formation of a protective film, friction or approach of a high voltage device, or the like. May not work. Further, the broken resistor 74 may be completely broken in a slight electrostatic application environment in a subsequent process, and the protection function may not work in the subsequent electrostatic application environment. Therefore, the line width (cross-sectional area) of the resistor 74 is equal to or larger than that of the MR element 36. For example, if the line width of the MR element 36 is 2 μm,
Is preferably at least 3 μm if at least 2 μm can be achieved. Resistor 74 depending on the number of times of folding back
Can be set to a desired value.

If the resistance value of the resistor 74 is too large, it is difficult for the electric charge to move from one pad 60 (62) to the other pad 62 (60), and an imbalance of electric charge occurs between the pads 60, 62. This makes it difficult to prevent the MR element 36 from being damaged by applying a large voltage to the MR element 36. When an experiment was conducted by setting the resistance value of the resistor 74 variously, destruction due to static electricity without the resistor 74 occurred at a probability of 10% or more, whereas static electricity was observed up to a resistance value of 5 kΩ. Destruction by 1 to 1.5%
It only increased a little at a time. When the resistance value was further increased, the probability of destruction increased slowly up to 10 kΩ, and the probability of destruction increased sharply above 10 kΩ. Did not.

On the other hand, if the resistance value of the resistor 74 is too small, the sense current to be supplied to the MR element 36 is shunted. Sensitivity is reduced. Normally, for a 10 to 50 Ω MR element,
If the resistance is set to 100 to 500Ω which is 0 times or more, the influence of the shunt is reduced to 1/10 or less, and the decrease in sensitivity due to the connection of the resistor 74 can be greatly reduced. Considering the above points,
It is desirable that the resistance value of the resistor 74 be 500Ω or more and 10kΩ or less. (Example of Design of Resistor 74) MR is applied between both terminals of MR element 36.
A resistor 74 having a width of 4 μm, a length of 1300 μm, and a thickness of 50 nm was formed of the same material as the element 36 to form a resistor 74.
At this time, in order to reduce the area occupied by the resistor 74, a skewed pattern was used as shown in FIG. The specific resistance of the resistor 74 was 45 Ωcm, and a total resistance value of about 3 kΩ was obtained after 30 turns. From the front of the magnetic head element, -10
When Ar ⁺ ions accelerated at 00 V were collided, the magnetic head without the resistor 74 was 10 to 15 minutes per minute.
%, While the magnetic head provided with the resistor 74 hardly caused any electrostatic breakdown.

Next, an example of the manufacturing process of the magnetic head of the present invention shown in FIGS. 1 and 2 will be described with reference to FIGS.

(1) An insulating film formed on a substrate (a wafer made of a ceramic material such as Al ₂ O ₃ —TiC or the like, which is cut later to constitute the slider 14 of the magnetic head) 76 A lower shield film 46 is formed in a predetermined shape on alumina (Al ₂ O _3, etc.) 72. The lower shield film 46 is made of permalloy (NiFe), sendust (F
eAlSi) is formed by depositing a soft magnetic film by sputtering, vapor deposition, plating or the like.

(2) An insulating film 78 of alumina or the like is deposited on the entire surface by sputtering or the like. (3) The entire surface is polished to form the lower shield film 46 to a predetermined thickness. (4) An insulating film 80 such as alumina is deposited on the entire surface by sputtering or the like to form a lower gap. (5) A magnet film 42 such as CoCrPt and a conductive film 44 such as W, Ta, Nb are sputtered on the lower gap 80.
They are laminated by vapor deposition or plating, and they are collectively etched, cut into an inverted trapezoidal shape, and leads 38, 4
0 is formed.

After the leads 38 and 40 are formed, an MR film 30 (NiFe or the like), a spacer film 32 (Ti or the like), a SAL bias film 34 (CoZ
A soft magnetic film such as rM (Nb, Mo, etc.) is laminated. The MR element 36 to be formed and the resistor 7 are formed thereon.
A resist is formed in the pattern No. 4 and unnecessary portions of the magnetic sensor film are removed by milling to form the MR element 36 and the resistor 74. Both ends 36a, 3 of the MR element 36
6b and both ends 74a, 74b of the resistor 74 are connected to the leads 40, 38 on the inclined surfaces 40a, 38a.

(6) Insulation between the upper shield film 48, the MR element 36 and the resistor 74 and the upper shield film 4
An insulating film 82 such as alumina is formed for a shield gap between the lead 8 and the leads 38 and 40 to form an upper gap.

(7) Soft magnetic film (NiFe, FeAlS)
i) is deposited by plating, vapor deposition, sputtering, or the like, and cut into a predetermined shape to form an upper shield film 48.
Then, an insulating film such as alumina is formed on the entire surface of the substrate and polished to form the upper shield and lower core 48 to a predetermined thickness. Insulation material 8 left around the upper shield and lower core 48
It is surrounded by 0.

(8) An alumina insulating film 50 is formed on the upper shield / lower core 48 to form a write gap. (9) The coil and the insulating layer 52 are formed. Leads 66 and 68 are drawn out from the terminals of the coil to form an insulating film 50.
Wired on top. Then, the upper core 54 is formed so as to straddle the coil and the insulating layer 52.

On the insulating film 50, pads 58, 60, 6
2, 64 are formed. Pads 58 and 64 are lead 6
6,68. Pads 60 and 62 are insulating film 5
0 and 82 are connected to the leads 38 and 40. Finally, a protective film 70 is formed and polished to form pad surfaces 58a,
The wafer process is completed by exposing 60a, 62a and 64a. Thereafter, the individual magnetic heads 10 are completed through the steps of cutting the substrate 76 to form rows, forming rails, cutting the rows, and forming individual sliders.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of a magnetic head according to the present invention, and is a perspective view showing a main part of an MR head of the magnetic head of FIG. 2;

FIG. 2 is a perspective view showing a magnetic head according to an embodiment of the present invention and a partially enlarged view thereof.

FIG. 3 is a front view showing a design example of a resistor according to the present invention.

FIG. 4 is a view showing one example of a method of manufacturing the magnetic head of FIGS. 1 and 2, and is a process drawing showing an embodiment of a manufacturing step of the magnetic head of the present invention.

FIG. 5 is a process drawing showing a continuation of FIG. 4;

FIG. 6 is a process drawing showing a continuation of FIG. 5;

[Explanation of symbols]

 Reference Signs List 10 thin-film magnetic head 14 slider 36 MR element (magnetic resistance sensor element) 38, 40 lead 60, 62 pad

Claims (4)

[Claims] A magnetoresistive sensor element having a resistance value changed by a magnetic field generated from a magnetic recording medium, and one end connected to both ends of the magnetoresistive sensor element to supply a sense current to the magnetoresistive sensor element. Each lead to
In a sensor-type thin-film magnetic head, in which each pad connected to the other end of each of these leads and constituting a connection portion of an external wiring is fixedly disposed on a slider, the one lead or pad and the other lead or pad are provided. And a resistor arranged in parallel with the magnetoresistive sensor element and fixedly disposed on the slider. 2. A method according to claim 1, wherein said resistor is made of the same material as said magnetoresistive sensor element, and a cross-sectional area of said resistor is equal to or larger than a cross-sectional area of said magnetoresistive sensor element. Item 2. A sensor-type thin film magnetic head according to Item 1. 3. The resistance value of the resistor is 500Ω or more and 10k or more.
3. The sensor-type thin-film magnetic head according to claim 1, wherein the resistance is equal to or less than Ω. 4. A magnetoresistive sensor element having a resistance value changed by a magnetic field generated from a magnetic recording medium, and one end connected to both ends of the magnetoresistive sensor element to supply a sense current to the magnetoresistive sensor element. Each lead to
Pads connected to the other ends of these leads to form connection portions for external wiring, and connected between the one lead or pad and the other lead or pad in parallel with the magnetoresistive sensor element. A method of manufacturing a sensor-type thin-film magnetic head in which an arrayed resistor is fixedly arranged on a slider, wherein the resistor is made of the same material as the magnetoresistive sensor element, and the resistor is made of the magnetic material. A method for manufacturing a sensor-type thin-film magnetic head, comprising forming a resistance sensor element at the same time as forming the resistance sensor element.