JP3878830B2 - Manufacturing method of suspension for magnetic head - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a suspension for a magnetic head, and more particularly to a method for manufacturing a suspension for a magnetic head that can reduce characteristic impedance and prevent delay of an electric signal.
[0002]
[Prior art]
As shown in FIG. 37, the magnetic head suspension 10 has a magnetic head element 12 mounted on the distal end side of a suspension body 11 made of a spring material such as stainless steel, and is electrically connected to the magnetic head element 12. A wiring pattern 13 to be formed is formed on the suspension body 11. Reference numeral 14 denotes a terminal portion for external connection.
As shown in FIG. 35, the wiring pattern 13 is formed on an insulating resin layer 15 made of polyimide resin, epoxy resin, acrylic resin, or the like, which is formed on the suspension body 11 with a required width, and is further photosensitive resin. The protective layer 16 is made of polyimide resin, epoxy resin, acrylic resin, resist or the like. The terminal portion 14 for external connection of the wiring pattern 13 is exposed.
Further, the portion of the wiring pattern 13 that is connected to the magnetic head element 12 is also exposed by forming an opening (not shown) in the protective layer 16.
[0003]
As a method of manufacturing such a suspension 10 for a magnetic head, there are methods disclosed in Japanese Patent Laid-Open Nos. 8-30946, 8-36721, and 8-45213.
22 to 35 show a general manufacturing method of the conventional suspension 10 for a magnetic head.
A brief description is given below.
First, as shown in FIG. 22, a photosensitive resist 21 is applied on a base material 20 made of a spring material such as stainless steel. It should be noted that a long metal plate is used as the base material 20 and is continuously fed by a reel-to-reel method, or a large area is used to simultaneously create a large number of magnetic head suspensions. Try to separate into pieces.
Next, the photosensitive resin 21 is exposed, developed and cured to form the insulating resin layer 15 in a required pattern (FIG. 23).
On the insulating resin layer 15, in order to improve the adhesion of the wiring pattern 13, a bonding metal layer 22 is formed by sputtering chromium and copper (FIG. 24).
[0004]
Next, the wiring pattern 13 is formed.
First, a photosensitive resist 23 was applied on the bonding metal layer 22 and the base material 20 (FIG. 25), and the photosensitive resist 23 was exposed and developed to form a resist pattern 23a (FIG. 26) and exposed. On the bonding metal layer 22, electrolytic copper plating, electrolytic nickel plating, and electrolytic gold plating are applied in this order to form the wiring pattern 13 (FIG. 27), the resist pattern 23a is removed (FIG. 28), and further the bonding metal The layer 22 is removed by etching (FIG. 29).
[0005]
Next, the protective layer 16 is formed.
That is, a photosensitive resin 24 is applied so as to cover the wiring pattern 13, the insulating resin layer 15, and the base material 20 (FIG. 30), and this photosensitive resin 24 is exposed, developed, and cured to form the protective layer 16 having a required pattern. (FIG. 31).
[0006]
Finally, separate into pieces.
That is, a photosensitive resist 25 is applied to cover the protective layer 16, the insulating resin layer 15, and the base material 20 (FIG. 32), and the photosensitive resist 25 is exposed and developed to form a resist pattern 25a (FIG. 33). The base material 20 is etched and separated into the suspension body 11 (FIG. 34), and the resist pattern 25a is removed to form the suspension 10 for the magnetic head (FIG. 35).
[0007]
By the way, recently, since the suspension device is downsized, the characteristic impedance is increased and the delay of the electric signal is generated.
In order to reduce the characteristic impedance and prevent the delay of the electric signal while keeping the suspension device downsized (while keeping the dimensions of the suspension body 11), the thickness of the insulating resin layer 15 and the wiring pattern 13 is increased. There is a need to.
At present, the sum of the thicknesses of the insulating resin layer 15 and the wiring pattern 13 is about 20 μm.
In order to satisfy the above characteristics, it is necessary to make the insulating resin layer 15 about 30 μm thick and the wiring pattern 13 about 20 μm thick.
[0008]
[Problems to be solved by the invention]
Therefore, the inventor tried to increase the thickness of the insulating resin layer 15 and the wiring pattern 13 to the required thickness, but the following problems occurred.
That is, when the photosensitive resin 24 is applied on the wiring pattern 13, the insulating resin layer 15, and the base material 20 to form the protective layer 16, the insulating resin layer 15 and the wiring pattern 13 are conventionally formed as shown in FIG. Therefore, the photosensitive resin 24 is pulled to the base material 20 side by surface tension, and cannot be applied with a sufficient thickness on the wiring pattern 13, and the corner portion of the wiring pattern 13 is exposed. A challenge has arisen.
Further, the photosensitive resin 24 itself becomes thick, and exposure light (ultraviolet rays) does not sufficiently reach the deep part of the photosensitive resin 24 at the time of exposure, resulting in poor exposure, and forming the protective layer 16 in a required shape. There was also a problem that it was difficult.
[0009]
Therefore, the present invention has been made to solve the above-mentioned problems, and the object is to form the insulating resin layer and the wiring pattern in a desired thickness without exposing the wiring pattern from the protective layer. An object of the present invention is to provide a method of manufacturing a suspension for a magnetic head that can reduce characteristic impedance and prevent delay of an electric signal.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, in the method for manufacturing a suspension for a magnetic head according to the present invention, an insulating resin layer is formed on a suspension body made of a spring metal plate, and a wiring pattern is formed on the insulating resin layer. In a method for manufacturing a suspension for a magnetic head in which a protective layer is formed so as to cover a wiring pattern, a step of forming an insulating resin layer on the entire surface of a base material made of a spring metal plate, and the unit on the insulating resin layer A step of forming a plurality of wiring patterns in a required arrangement, and applying a photosensitive resin for a protective layer covering the whole of the plurality of unit wiring patterns, exposing, developing and curing the photosensitive resin, forming a protective layer covering independently a wiring pattern, the insulating resin layer and covering the protective layer and photosensitive resist is coated, exposing the photosensitive resist, developing the insulating resin layer Forming a resist pattern to expose the pointing should site, the resist pattern as a mask, by etching the insulating resin layer with an etchant which does not attack the resist pattern, independent the each unit wiring patterns rests pattern And etching the resist pattern with an etchant that does not invade the insulating resin layer, and etching the base material to separate the suspension body for each unit wiring pattern. And an etching process.
[0011]
Forming the unit wiring pattern; forming a bonding metal layer on the entire surface of the insulating resin layer; applying a photosensitive resist on the bonding metal layer; exposing and developing the photosensitive resist; Forming a resist pattern in which the bonding metal layer is exposed on the unit wiring pattern, and forming a copper layer on the exposed bonding metal layer by plating to form the unit wiring pattern. A plating step to be formed, a step of removing the resist pattern, and an etching step of removing the exposed metal layer for bonding using the copper layer as a mask can be performed.
It is preferable that the insulating resin layer has a thickness of 30 μm and the unit wiring layer has a thickness of 20 μm .
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Since the structure of the finally formed suspension for the magnetic head is basically the same as the conventional one shown in FIG. 37, the drawing is omitted, and the manufacturing process will be described below.
[0013]
First, as shown in FIG. 1, a polyimide resin 30 is applied to the entire surface of a base material 20 made of a spring material such as stainless steel, and cured and cured. The thickness of the polyimide resin 30 is approximately 30 μm.
Conventionally, this polyimide resin is patterned to form the insulating resin layer 15 in the first stage. In the present embodiment, however, patterning is not performed in this stage.
It should be noted that a long metal plate is used as the base material 20 and is continuously fed by a reel-to-reel method, or a large area is used to simultaneously create a large number of magnetic head suspensions. The point which makes it isolate | separate into a piece is the same as the past.
Further, instead of the polyimide resin 30, an insulating resin such as an epoxy resin or an acrylic resin may be used.
On this polyimide resin layer 30, in order to improve the adhesion of the wiring pattern 13, a bonding metal layer 22 is formed by sputtering chromium and copper (FIG. 2).
[0014]
Next, the wiring pattern 13 is formed. That is, a plurality of unit wiring patterns 13 are formed in a required pattern on the bonding metal layer.
The wiring pattern 13 can be formed by a process similar to the conventional process.
First, a photosensitive resist 23 is applied on the bonding metal layer 22 and the base material 20 (FIG. 3), and the photosensitive resist 23 is exposed and developed to form a resist pattern 23a (FIG. 4), which is exposed. On the bonding metal layer 22, electrolytic copper plating, electrolytic nickel plating, and electrolytic gold plating are applied in this order to form the wiring pattern 13 (FIG. 5), the resist pattern 23a is removed (FIG. 6), and further exposed. The joining metal layer 22 is removed by etching (FIG. 7).
The thickness of the wiring pattern 13 is approximately 20 μm.
[0015]
It is not always necessary to form the wiring pattern 13 as described above.
For example, a copper foil is thermocompression-bonded on the polyimide resin layer 30, the copper foil is etched and patterned, and a necessary plating film is formed to form the wiring pattern 13. In this case, it is not necessary to provide the bonding metal layer 22.
[0016]
Next, the protective layer 16 is formed.
That is, a plurality of (unit) wiring patterns 13 and a polyimide resin layer 30 are covered and a photosensitive resin 24 is applied (FIG. 8), and the photosensitive resin 24 is exposed, developed, and cured, and each unit wiring pattern 13 is formed. It forms in the protective layer 16 which covers independently (FIG. 9). The photosensitive resin includes polyimide resin, epoxy resin, acrylic resin, and resist.
In this case, the polyimide resin layer 30 is formed on the entire surface of the base material 20, and no step difference is formed between the polyimide resin layer 30 and the base material 20. That is, the photosensitive resin 24 covers the wiring pattern 13, and this wiring pattern 13 is formed to a thickness of about 20 μm, which is about the same as the sum of the thicknesses of the conventional insulating resin layer 15 and the wiring pattern 13. Therefore, when the photosensitive resin 24 is applied, the corner portion of the wiring pattern 13 is not exposed and is sufficiently exposed by exposure light (ultraviolet rays), so that exposure and development are good. The wiring pattern 13 can be completely covered with the protective layer 16.
[0017]
Next, the polyimide resin layer 30 is formed in a required pattern.
First, as shown in FIG. 10, a photosensitive resist 32 is applied so as to cover the polyimide resin layer 30 and the protective layer 16. The photosensitive resist 32 is exposed and developed to form a resist pattern 32a in which a portion to be removed of the polyimide resin layer 30 is exposed (FIG. 11), and the polyimide resin layer exposed using the resist pattern 32a as a mask. 30 portions are removed by etching to form an insulating resin layer 15 on which each wiring pattern 13 is placed independently (FIG. 12). Next, the resist pattern 32a is removed by etching (FIG. 13).
Incidentally, as the etching of the polyimide resin layer 30 is not resist pattern 32a is attacked by the etchant, and as resist pattern 32a polyimide resin layer 30 by the etchant during the removal of not attacked, mutual It is necessary to select the type of resin and the type of etching solution.
[0018]
Instead of forming the resist pattern 32a, a mask plating film may be formed on the protective layer 16 and a necessary area around it (not shown). This plating is preferably performed by electroless copper plating and then electrolytic copper plating to form a copper film. It is also possible to form a copper film by sputtering chromium and copper and performing electrolytic copper plating thereon.
The polyimide resin layer 30 is etched using this copper film as a mask. Then, the copper film may be removed by etching. By doing so, it is not necessary to pay much attention to the type of etching solution.
[0019]
Finally, the base material 20 is etched and separated into a single magnetic head suspension.
That is, as shown in FIG. 14, a photosensitive resist 25 is applied so as to cover the base material 20, the insulating resin layer 15, and the protective layer 16. Next, the photosensitive resist 25 is exposed and developed to form a resist pattern 25a (FIG. 15), and the base material 20 is etched using the resist pattern 25a as a mask to be separated into the suspension body 11 (FIG. 16). Finally, the resist pattern 25a can be removed to form the magnetic head suspension 10 (FIG. 17).
[0020]
18 to 21 show another embodiment.
1 to 7 are the same as those in the above embodiment.
In the present embodiment, the method for forming the protective layer 16 is different from the above embodiment.
That is, as shown in FIG. 18, the wiring pattern 13 and the polyimide resin layer 30 are covered, and a non-photosensitive resin, for example, a non-photosensitive polyimide resin 34 is applied and cured and cured.
Next, as shown in FIG. 19, electroless plating and electrolytic plating are performed in a required area on the polyimide resin cured layer 34 to form a plating film 35 for a mask, and both polyimide layers 30, Insulating resin layer 15 and protective layer 16 are formed simultaneously by etching 34 (FIG. 20). Next, the plating film 35 is removed by etching (FIG. 21).
Finally, in the same manner as the steps shown in FIGS. 14 to 17, the base material 20 is etched and separated into a single magnetic head suspension 10.
[0021]
【The invention's effect】
As described above, according to the present invention, the insulating resin layer is formed on the entire surface of the base material, the wiring pattern is formed on the insulating resin layer, and the resist for the protective layer is applied to cover the wiring pattern. Therefore, even if the wiring pattern is thick, the protective layer can be formed without exposing the corners of the wiring pattern.
Therefore, it is possible to provide an excellent method for manufacturing a suspension for a magnetic head that can increase the thickness of the insulating resin layer and the wiring pattern, reduce the characteristic impedance, and prevent the delay of the electric signal.
[Brief description of the drawings]
1 to 17 show a first embodiment of a manufacturing process,
FIG. 1 is a sectional view showing a state in which a polyimide resin layer is formed on a base material;
FIG. 2 is a sectional view showing a state in which a bonding metal layer is formed on a polyimide resin layer;
FIG. 3 is a cross-sectional view of a state where a photosensitive resist is applied,
FIG. 4 is a sectional view showing a state in which a resist pattern is formed;
FIG. 5 is a sectional view showing a state in which a wiring pattern is formed;
FIG. 6 is a cross-sectional view of the state where the resist pattern is removed;
FIG. 7 is a cross-sectional view showing a state where an exposed bonding metal layer is removed;
FIG. 8 is a cross-sectional view of a state where a photosensitive resin is applied,
FIG. 9 is a sectional view showing a state in which a protective layer is formed;
FIG. 10 is a cross-sectional view of a state where a photosensitive resist is applied,
FIG. 11 is a sectional view showing a state in which a resist pattern is formed;
FIG. 12 is a cross-sectional view of the polyimide resin layer etched;
FIG. 13 is a cross-sectional view showing a state where a resist pattern is removed;
FIG. 14 is a sectional view of a state where a photosensitive resist is applied,
FIG. 15 is a sectional view showing a state in which a resist pattern is formed;
FIG. 16 is a cross-sectional view showing a state where the base material is etched;
FIG. 17 is a cross-sectional view showing a state where a resist pattern is removed and separated into a suspension for a magnetic head.
18 to 21 show a second embodiment of the manufacturing process,
FIG. 18 is a cross-sectional view of a state in which a protective layer resin is applied,
FIG. 19 is a cross-sectional view of a state where a mask plating film is formed;
FIG. 20 is a cross-sectional view of a state in which a protective layer and an insulating resin layer are formed by etching;
FIG. 21 is a cross-sectional view showing a state where a plating film is removed.
22 to 35 show conventional manufacturing process diagrams,
FIG. 22 is a cross-sectional view showing a state where photosensitive polyimide is applied on a base material;
FIG. 23 is a cross-sectional view of an insulating resin layer formed by exposure and development;
FIG. 24 is a cross-sectional view of a state where a bonding metal layer is formed;
FIG. 25 is a sectional view of a state where a photosensitive resist is applied,
FIG. 26 is a sectional view showing a state in which a resist pattern is formed;
FIG. 27 is a sectional view showing a state in which a wiring pattern is formed;
FIG. 28 is a cross-sectional view of the state where the resist pattern is removed;
FIG. 29 is a cross-sectional view showing a state where the exposed bonding metal layer is removed;
FIG. 30 is a sectional view of a state where a photosensitive resin is applied,
FIG. 31 is a sectional view showing a state in which a protective layer is formed;
FIG. 32 is a cross-sectional view of a state where a photosensitive resist is applied,
FIG. 33 is a sectional view showing a state in which a resist pattern is formed;
FIG. 34 is a cross-sectional view showing a state where the base material is etched,
FIG. 35 is a cross-sectional view showing a state where the resist pattern is removed and separated into a suspension for a magnetic head.
FIG. 36 is a cross-sectional view for explaining a situation where a protective resist for a protective layer is applied when the insulating resin layer and the wiring pattern are thickened;
FIG. 37 is a perspective view showing a suspension for a magnetic head in a state where a protective layer is omitted.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Magnetic head suspension 11 Suspension main body 12 Magnetic head element 13 Wiring pattern 15 Insulating resin layer 16 Protective layer 20 Base material 22 Joining metal layer 23 Photosensitive resist 23a Resist pattern 24 Photosensitive resin 25 Photosensitive resist 25a Resist pattern 30 Polyimide Resin layer 32 Photosensitive resist 32a Resist pattern 34 Polyimide resin 35 Plating film

Claims (3)

In a method for manufacturing a suspension for a magnetic head, an insulating resin layer is formed on a suspension body made of a spring metal plate, a wiring pattern is formed on the insulating resin layer, and a protective layer is formed to cover the wiring pattern.
Forming an insulating resin layer on the entire surface of the base metal made of a spring metal plate;
Forming a plurality of unit wiring patterns in a required arrangement on the insulating resin layer;
A step of covering the whole of the plurality of unit wiring patterns, applying a photosensitive resin for a protective layer, exposing, developing, and curing the photosensitive resin to form a protective layer that independently covers each unit wiring pattern When,
Covering the insulating resin layer and the protective layer, applying a photosensitive resist, exposing and developing the photosensitive resist to form a resist pattern exposing a portion to be removed of the insulating resin layer; and
Using the resist pattern as a mask, the insulating resin layer is etched with an etchant that does not attack the resist pattern, and an etching process for separating the unit wiring patterns into independent patterns,
Etching and removing the resist pattern with an etchant that does not attack the insulating resin layer;
And a step of etching the base material to separate the suspension wiring body for each unit wiring pattern into a suspension body. Forming the unit wiring pattern comprises:
Forming a bonding metal layer on the entire surface of the insulating resin layer;
A photolithographic step of applying a photosensitive resist on the bonding metal layer, exposing and developing the photosensitive resist, and forming a resist pattern in which the bonding metal layer is exposed in the pattern of the unit wiring pattern; ,
A plating step of forming a unit wiring pattern by forming a copper layer on the exposed bonding metal layer by plating;
Removing the resist pattern;
2. The method of manufacturing a suspension for a magnetic head according to claim 1, further comprising an etching step of removing the exposed bonding metal layer using the copper layer as a mask. 3. The method of manufacturing a suspension for a magnetic head according to claim 1, wherein the insulating resin layer is formed to a thickness of 30 [mu] m , and the unit wiring layer is formed to a thickness of 20 [ mu] m .

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