JPH0997408A - Thin-film magnetic head and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the yield in the production stage by forming the surface of a pad layer flush with or lower than the surface of a protective layer. SOLUTION: A terminal layer 14 is formed via an insulating layer 2 on a substrate and the bump layer 12 is formed at several μm thickness via a seed layer 11 on this terminal layer 14. The surface thereof is enclosed by the protective layer 16 having 30 to 40μm thickness. The seed layer 19 consisting of Ni-Fe or Au, etc., is formed at nearly 1000Å thickness on the surface of the bump layer 12 and, further, the pad layer 13 consisting of Au is formed at several μm thickness on the surface of the seed layer 19 and is formed lower than the surface of the protective layer 16. The surface of the pad layer 13 is formed flush with the surface of the protective layer 16 or lower than the surface of the protective layer 16, thereby, the yield in the production stages is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film magnetic head, and more particularly to a thin film magnetic head in which a pad layer is formed at the tip of a terminal layer extending from the head element via a bump layer in order to connect the head element to an external circuit. The present invention relates to a head and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a thin-film magnetic head is generally provided with an inductive head element capable of writing and reading signals, but it is compatible with the recent increase in recording density in magnetic recording devices. Therefore, it has a thin film magnetic head for reproduction only having a magnetoresistive (MR) head element, a composite thin film magnetic head integrally including an inductive head element and an MR head element, and further has a bulk core. Hybrid type MIG in which the coil is formed of a thin film together with
(Metal in gap) head has been developed. In a thin film magnetic head compatible with such high recording density,
In order to connect the head element to an external circuit, a pad layer is formed at the tip of a terminal layer extending from the head element via a bump layer, and a lead wire is bonded to the pad layer.

For example, as shown in FIGS. 5 and 6, a floating type composite thin film magnetic head, which is generally equipped in a hard disk drive, etc., is used for signal recording on a side surface of a substrate (1) which serves as a head slider. Inductive head element H1
And an MR head element H2 for signal reproduction,
Four bump layers (15), (15), (15) and (15) for connecting both head elements to an external circuit are formed on the side surface.
In addition, on the surface of the substrate (1) facing the disk, an air bearing surface S and a lateral pressing cross-sectional shape (Transverse Pressuriza
A groove C is provided to provide a motion contour.
The pair of electrode layers 6 and 6 extending from each head element and the pair of bump layers 15 and 15 are connected to each other by terminal layers 14 and 14. Also, both head elements and terminal layers
(14) is covered by a protective layer (16).

Further, a pad layer (17) is formed on the surface of the bump layer (15) as shown in FIG. 7, and a lead wire (18) is bonded to the pad layer (17).

In the manufacturing process of the composite type thin film magnetic head as described above, a large number of head modules (90) are formed on the wafer serving as the substrate (1). Each head module (90)
In the forming step of (1), after the MR head element H2 and the inductive head element H1 are formed on the wafer by using the thin film deposition method and the photolithography technique, the terminal layer (14) is formed into a predetermined pattern, and then the terminal layer (14) is formed. A bump layer (15) is formed so as to overlap the tip of the terminal layer (14), and then a protective layer (16) is formed to cover both head elements and the bump layer (15).

Finally, the surface of the protective layer (16) is polished to expose the surface of the bump layer (15) and the surface of the bump layer (15) is plated with gold to form a pad layer (17). Of.

In this way, a large number of head modules (90)
The wafer on which is formed is first divided into bar-shaped head blocks by a slicing process, and then divided into heads, and further subjected to a cleaning process (ultrasonic cleaning, wiping cleaning with a cloth, etc.), and a composite thin film magnetic head. Is completed.

[0008]

However, in the conventional thin film magnetic head, as shown in FIG.
Since the surface of (17) is formed higher than the surface of the protective layer (16), the pad layer (17) may be subjected to a large external force in the subsequent cleaning step and may be separated from the bump layer (15). is there. Further, in the groove forming step of processing the groove C on the surface of the substrate (1) facing the disk by etching, as shown in FIGS.
Fixing the plurality of head blocks (93) on the base (91),
After applying a resist (92) on the surface, exposure and development processing is performed to open the processing area of the groove C, and the opening area is etched. However, the pad layer (1
Since the surface of (7) is formed higher than the surface of the protective layer (16), a gap G is generated between the head blocks (93) when the head blocks (93) are arranged, and the resist (92) is formed as shown in FIG. Uneven coating occurs. As a result, an error occurs in the opening shape for the groove processing, which reduces the accuracy of the groove processing, and there is a problem that the yield in the manufacturing process of the thin film magnetic head is reduced. An object of the present invention is to improve the processing accuracy in the process of manufacturing a thin film magnetic head, in which the pad layer is peeled off when cleaning is performed after the head module is formed, and when the groove is formed on the surface facing the disk. is there.

[0009]

A thin film magnetic head according to the present invention comprises at least one head element on a substrate, and a bump layer is laminated on the tip of a plurality of terminal layers drawn from the head element. Then, a protective layer is formed to cover the head element and surround the bump layer, and on the bump layer,
In a thin film magnetic head in which a pad layer for connecting to an external circuit is laminated, the surface of the pad layer is formed to be flush with the surface of the protective layer or lower than the surface of the protective layer. .

Specifically, a seed layer, which serves as a base for the plating process, is interposed between the bump layer and the pad layer, or the pad layer is directly laminated on the surface of the bump layer.

In the thin film magnetic head of the present invention,
Since the surface of the pad layer is formed so as to be flush with the surface of the protective layer or lower than the surface of the protective layer, the pad layer is not subjected to a large external force, and peeling of the pad layer in the cleaning process is prevented. To be prevented. Further, since a plurality of head blocks can be arranged without gaps in the groove forming step, uneven coating of the resist is prevented and the groove processing accuracy is improved.

In the method for manufacturing a thin film magnetic head according to the present invention, at least one head element is formed on a substrate, and a first step of forming a plurality of terminal layers extending from the head element; A second step of stacking a bump layer on the tip portion and surrounding the bump layer to form a protective layer, and forming a seed layer as a base of plating treatment on the surface of the bump layer and forming the seed layer The third step of forming a pad layer for connecting to an external circuit on the surface. Then, in the second step, a step of forming a bump layer on the upper surface of the terminal layer by plating, a step of forming a protective layer covering the head element and the bump layer, and a surface processing of the surface of the protective layer are performed. , Exposing the surface of the bump layer, and etching the surface of the protective layer and the bump layer with selectivity to process the surface of the bump layer to be lower than the surface of the protective layer. . In the third step, after forming a seed layer which covers the bump layer and the protective layer around the bump layer and serves as an underlayer for plating, a resist in which a region overlapping with the surface of the bump layer is opened on the surface of the seed layer. The step of forming the frame and the plating of the opening area of the resist frame to form a pad layer having a thickness such that the surface is flush with the surface of the protective layer or the surface is lower than the surface of the protective layer. And a step of removing the resist frame, etching the surface of the seed layer, and removing the seed layer portion that extends outside the outer peripheral edge of the pad layer.

According to the method of manufacturing a thin film magnetic head described above,
A thin film magnetic head according to claim 2 of the present invention can be obtained. In the manufacturing method, in the second step, by selectively etching the surfaces of the protective layer and the bump layer, the surface of the bump layer is etched faster than the surface of the protective layer, or Only the surface of the layer is etched so that finally the surface of the bump layer is well below the surface of the protective layer. This difference in surface height is set to an appropriate size so that the surface of the pad layer laminated on the surface of the bump layer in the next third step is the same as or lower than the surface of the protective layer. . As a result, a thin film magnetic head in which the surface of the pad layer is flush with the surface of the protective layer or which is lower than the surface of the protective layer is completed.

Another method of manufacturing a thin film magnetic head according to the present invention comprises a first step of forming at least one head element on a substrate and forming a plurality of terminal layers extending from the head element, The second step of forming a resist frame in which the front end of the terminal layer is opened on the upper surface of the terminal layer, and plating the opening area of the resist frame so that the surface is lower than the surface of the resist frame. A third step of forming a bump layer and a step of forming a pad layer used for connection to an external circuit,
A fourth step of forming a pad layer on the surface of the bump layer by plating an opening region of the resist frame, and a fifth step of removing the resist frame and then forming a protective layer covering the bump layer and the pad layer. And a sixth step of exposing the surface of the pad layer by subjecting the surface of the protective layer to planar processing.

According to the method of manufacturing a thin film magnetic head described above,
A thin film magnetic head according to claim 3 of the present invention can be obtained. In the manufacturing method, in the second step, after forming the bump layer using the resist frame, the resist frame is not removed and this is used for the formation of the next pad layer. At this time, by forming the resist frame to have a thickness larger than the total thickness of the bump layer and the pad layer, continuous plating can be performed. In this way, by successively forming the bump layer and the pad layer using the common resist frame, these layers have the same planar shape. Then, in the sixth step, the surface of the pad layer and the surface of the protective layer are subjected to planar processing until the surface of the pad layer is exposed, so that these surfaces are flush with each other. As a result, a thin film magnetic head in which the surface of the pad layer is flush with the surface of the protective layer is completed.

[0016]

According to the thin-film magnetic head and the method of manufacturing the same of the present invention, the surface of the pad layer is flush with the surface of the protective layer,
Alternatively, the yield of the manufacturing process is improved by lowering the protective layer from the surface.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Below, the present invention is embodied in a floating composite thin-film magnetic head equipped in a hard disk drive device and the like, and will be specifically described along two examples. First Embodiment The structure of the composite type thin film magnetic head of this embodiment is the same as that of the conventional one shown in FIG. 5 except for the bump layer and the pad layer. Instead of the bump layer (12), the overall structure will be described first. As shown in FIG. 5, a head slider having an air bearing surface S and a groove C is formed by a substrate (1) made of Al ₂ O ₃ —TiC, and a side surface of the substrate (1) for recording signals. Inductive head element H1 and MR head element H2 for signal reproduction.

FIG. 6 shows the structure of the two head elements H1 and H2 as viewed from the side facing the magnetic recording medium. On the substrate (1), an insulating layer (2) made of Al ₂ O ₃ , Ni,
A shield layer (3) made of —Fe alloy, a lower insulating layer (4) made of Al ₂ O ₃ , an MR element layer (5) made of Ni—Fe alloy,
The MR type head element H2 is formed by laminating the electrode layers (6) and (6) made of Cu and the upper insulating layer (7) made of Al ₂ O ₃ . Further, on the head element, a lower core layer (8) made of a Ni--Fe alloy, a gap spacer layer (9) made of Al ₂ O ₃ , an upper core layer (80) made of a Ni--Fe alloy, and Al. _The inductive head element H1 is constructed by laminating the protective layer (16) made of ₂ O ₃ .

As shown in FIG. 5, the inductive head element H1 comprises a coil layer (10) which extends around the upper core layer (80), and both ends of the coil layer (10) have a pair of terminal layers (14). ) (14), and is connected to the pair of bump layers (12) (12). On the other hand, in the MR head element H2, the pair of electrode layers (6) and (6) extending from the MR element layer (5) are the pair of terminal layers (14).
It is connected to the pair of bump layers (12) and (12) via (14).
Here, the terminal layer 14 and the bump layer 12 are formed of Cu. The electrode layer (6) and the terminal layer (14) are covered with a protective layer (16) together with both head elements, the bump layer (12) is surrounded by the protective layer (16), and the surface thereof is a protective layer (16). It is formed lower than the surface of 16). Bump layer (1
A pad layer (not shown) is formed on the surface of 2) lower than the surface of the protective layer (16).

FIG. 1 is an enlarged cross-sectional view taken along the line A--A of FIG. 5 in a state where the bump layer (12) and the pad layer (13) are formed. The insulating layer (2) is formed on the substrate (1). ), The terminal layer (14) is formed, and the bump layer (12) is formed on the terminal layer (14) through the seed layer (11).
The bump layer (12) has a thickness of several μm and a thickness of 30-4.
It is surrounded by a 0 μm protective layer (16).

A seed layer (19) made of Ni-Fe or Au is formed on the surface of the bump layer (12) to a thickness of about 1000Å. A pad layer (13) is formed. The pad layer (13) has a thickness of several μm and is formed lower than the surface of the protective layer (16).

In the manufacturing process of the composite type thin film magnetic head, a large number of head modules are simultaneously formed on the wafer to be the substrate (1). In the head module forming step, after the MR head element H2 and the inductive head element H1 are formed on the wafer by using the thin film deposition method and the photolithography technique, the terminal layer (14) is formed in a predetermined pattern, and subsequently, Seed layer at the tip of the terminal layer (14)
A bump layer (12) is formed via (11).

FIGS. 3A to 3F show specific steps from the formation of the bump layer 12 to the formation of the pad layer 13. As shown in FIG. 3 (a), a bump layer (12) having a thickness of 30 to 40 μm is formed on the tip of the terminal layer (14) by copper plating through the seed layer (11). A protective layer made of Al ₂ O ₃ covering the bump layer (12)
(16) is deposited by sputtering to a thickness of about 40 μm.

Next, as shown in FIG. 3B, the surface of the protective layer 16 is polished to expose the bump layer 12. After that, the same figure
As shown in (c), the surfaces of the bump layer 12 and the protective layer 16 are subjected to wet etching or ion beam etching. In wet etching, for example, a bump layer
The bump layer (1) is formed by immersing the protective layer (16) and the protective layer (16) in an aqueous solution of ferric chloride having selectivity for Cu and Al ₂ O _3.
Only the surface of 2) is etched. In the ion beam etching, for example, the bump layer (12) and the protective layer (1
By irradiating the surface of 6) with an ion beam having an Al ₂ O ₃ etching rate of 1/4 with respect to the Cu etching rate, the surface of the bump layer (12) is protected by a protective layer (16).
Etch at a faster rate than the surface. In this way, the bump layer 12 is processed to have a thickness of several μm.

Subsequently, as shown in FIG. 3D, a seed layer 19 made of Ni-Fe or Au is sputtered to cover the bump layer 12 and the protective layer 16 to a thickness of about 1000 Å. To form. Then, a resist is applied to the entire surface of the seed layer (19), and the resist is exposed and developed to form an opening (22a) in a pad layer forming region, and a resist frame (22) having a thickness of several μm. To form. Next, the same figure
As shown in (e), the opening (22a) of the resist frame (22) is plated with gold to form a pad layer (13) having a thickness of several μm.

Thereafter, as shown in FIG. 3 (f), the resist frame (22) is removed by an organic solvent such as acetone, and then the surface of the seed layer (19) is subjected to wet etching or ion beam etching to form a pad layer. The seed layer portion extending outside the outer peripheral edge of is removed.

A large number of head modules thus formed on the wafer are individually divided by a slicing process, and further subjected to a cleaning process (ultrasonic cleaning, wiping cleaning with a cloth or the like), and then FIG. The composite type thin film magnetic head shown in FIG. 6 is completed.

In the thin film magnetic head of the first embodiment described above, the thickness of the protective layer (16) is 30 to 40 μm, while the thickness of the bump layer (12) and the pad layer (13) is. Since the seed layer (19) has a thickness of a few μm and a thickness of 1000Å, the pad layer (1
The surface of 3) is lower than the surface of the protective layer (16). As a result, the peeling of the pad layer in the cleaning step is prevented, and in the step of forming the groove on the surface facing the disk, the head blocks can be arranged without a gap, so that uneven coating of the resist is prevented, This makes it possible to improve the machining accuracy of the groove. As a result, the yield in the manufacturing process is improved. In the manufacturing method of the first embodiment, when the surface of the protective layer (16) is polished to expose the bump layer (12), the surfaces of the bump layer (12) and the protective layer (16) are Contaminated by polishing liquid. However, when ion beam etching is performed in the step of processing the bump layer (12) to a thickness of several μm, the surfaces of the contaminated bump layer (12) and the protective layer (16) are cleaned by the ion beam. So the bump layer
The adhesion strength of the seed layer (19) to the (12) and the protective layer (16) can be increased.

Second Embodiment FIG. 2 shows the structure of the composite type thin film magnetic head of this embodiment.
While the pad layer in the first embodiment is formed lower than the surface of the protective layer (16), in the present embodiment, the pad layer (2
1) is formed so as to be flush with the surface of the protective layer (16).

A terminal layer (14) is formed on the substrate (1) via an insulating layer (2), and a bump layer (20) is formed on the terminal layer (14) via a seed layer (11). Has been done. The bump layer (20) has a thickness of several μm and a thickness of 30 to 40 μm.
It is surrounded by a protective layer (16).

A pad layer (21) made of Au is directly formed on the surface of the bump layer (20). The pad layer (21)
Has a thickness of several μm and is formed flush with the surface of the protective layer (16).

FIGS. 4A to 4D show specific steps from the formation of the seed layer 11 to the formation of the pad layer 21. First, a resist is applied to the entire surface of the seed layer (11) shown in FIG. 4 (a), and then the resist is exposed and developed to form an opening (23a) in the formation region of the bump layer (20).
To form a resist frame (23). The thickness of the resist frame (23) is larger than the total thickness of the bump layer (20) and the pad layer (21) which will be formed in a later step. Then, the openings (23a) of the resist frame (23) are plated with copper to form bump layers (20). The steps up to this point are the same as those of the prior art and the first embodiment, but the resist frame (23) is left without being removed.

Next, as shown in FIG. 4B, the resist frame (2
Gold plating is applied to the opening (23a) of 3), and the bump layer (20)
A pad layer (13) having a thickness of several μm is directly formed on the surface of the.

Then, as shown in FIG. 4C, a resist frame
After removing (23) with an organic solvent such as acetone, the bump layer (20) and the pad layer (21) are covered with a protective layer (16) made of Al ₂ O ₃ by sputtering to a thickness of about 40 μm. Form a film.

Then, as shown in FIG. 4D, the surface of the protective layer 16 is polished or wet-etched to expose the pad layer 21.

A large number of head modules thus formed on the wafer are individually divided by a slicing process, and further subjected to a cleaning process (ultrasonic cleaning, wiping cleaning with a cloth or the like), and then, as shown in FIGS. The composite type thin film magnetic head shown in FIG. 6 is completed.

In the thin film magnetic head of the second embodiment, in the manufacturing method thereof, the pad layer (21) is formed on the surface of the bump layer (20).
After forming the protective layer (16) and exposing the surface of the pad layer (21), the surface of the pad layer (21) is protected by the protective layer (16).
It is flush with the surface of. Therefore, peeling of the pad layer in the cleaning step is prevented, and in the step of forming the groove on the surface facing the disk, the head blocks can be arranged without a gap, so that uneven coating of the resist can be prevented. By doing so, it is possible to improve the machining accuracy of the groove. As a result, the yield in the manufacturing process is improved. Further, in the manufacturing method of the second embodiment, since the bump layer is formed and then the pad layer is continuously formed, the seed layer and the resist frame are commonly used for the formation of the bump layer and the pad layer. Therefore, it is possible to omit the seed layer forming step and the resist frame forming step, which have conventionally been required to be performed again for forming the pad layer.

According to the above two embodiments, the yield of the manufacturing process is improved by making the surface of the pad layer flush with the surface of the protective layer or lower than the surface of the protective layer.

The description of the above embodiments is for the purpose of describing the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims.

[Brief description of drawings]

FIG. 1 is a sectional view showing a laminated structure of a bump layer and a pad layer in a first embodiment.

FIG. 2 is a sectional view showing a laminated structure of a bump layer and a pad layer in a second embodiment.

FIG. 3 is a manufacturing process diagram in the first embodiment.

FIG. 4 is a manufacturing process diagram in the second embodiment.

FIG. 5 is a perspective view showing an appearance of a composite type thin film magnetic head.

FIG. 6 is an enlarged front view of two head elements as seen from a surface facing a recording medium.

FIG. 7 is a cross-sectional view showing a pad layer to be formed on a conventional bump layer.

FIG. 8 is a diagram showing an arrangement state of head blocks in a slicing process.

FIG. 9 is a partially cutaway perspective view showing a resist coating state in a groove forming step.

[Explanation of symbols]

 (1) Substrate (2) Insulating layer (11) Seed layer (12) Bump layer (13) Pad layer (14) Terminal layer (16) Protective layer (19) Seed layer (20) Bump layer (21) Pad layer

Claims (5)

[Claims] 1. A substrate is provided with at least one head element, and a bump layer is laminated on a tip portion of a plurality of terminal layers drawn out from the head element to cover the head element and surround the bump layer. In a thin film magnetic head in which a protective layer is formed and a pad layer for connecting to an external circuit is laminated on the bump layer, the surface of the pad layer is flush with the surface of the protective layer, Alternatively, the thin-film magnetic head is characterized in that it is formed lower than the surface of the protective layer. 2. The thin film magnetic head according to claim 1, wherein a seed layer serving as an underlayer for plating is interposed between the bump layer and the pad layer. 3. The thin film magnetic head according to claim 1, wherein a pad layer is directly laminated on the surface of the bump layer. 4. A first step of forming at least one head element on a substrate and forming a plurality of terminal layers extending from the head element, and laminating a bump layer on a tip portion of the terminal layer, A second step of forming a protective layer surrounding the bump layer, forming a seed layer as a base of plating treatment on the surface of the bump layer, and forming a seed layer on the surface of the seed layer for connection with an external circuit. In the method of manufacturing a thin-film magnetic head, which comprises a third step of forming a pad layer, the second step includes a step of forming a bump layer on the upper surface of the terminal layer by plating, a head element and a bump layer. To form a protective layer, to cover the surface of the protective layer to expose the surface of the bump layer by planarization, and to etch the surface of the protective layer and the bump layer with selectivity. And a step of processing the surface of the bump layer to be lower than the surface of the protective layer. In the third step, a seed layer serving as an underlayer for plating is formed to cover the bump layer and the peripheral protective layer. After that, on the surface of the seed layer,
The step of forming a resist frame in which the area overlapping the surface of the bump layer is opened, and plating is applied to the opening area of the resist frame so that the surface is flush with the surface of the protective layer, or the surface is more than the protective layer surface. And a step of removing the resist frame and then etching the surface of the seed layer to remove the seed layer portion that extends outside the outer peripheral edge of the pad layer. A method of manufacturing a thin film magnetic head comprising. 5. A first step of forming at least one head element on a substrate and forming a plurality of terminal layers extending from the head element; and opening a tip portion of the terminal layer on an upper surface of the terminal layer. A second step of forming a resist frame, a third step of plating an opening region of the resist frame to form a bump layer having a thickness lower than the surface of the resist frame, and an external circuit. A step of forming a pad layer used for connection, wherein the opening region of the resist frame is plated to form a pad layer on the surface of the bump layer;
A step of removing the resist frame and then forming a protective layer covering the bump layer and the pad layer, and a sixth step of exposing the surface of the pad layer by planarizing the surface of the protective layer. A method of manufacturing a thin film magnetic head comprising: