JP4371595B2 - Slider processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slider processing method when manufacturing a slider on which a head element is mounted, and more particularly to a slider processing method when a wafer on which a large number of head elements are formed is cut into individual elements to form a slider.
[0002]
[Prior art]
In recent years, in magnetic disk devices and the like, efforts to increase the recording density for recording media are being strengthened, and the adoption of GMR heads with excellent high-density recording / reproducing characteristics and the narrowing of recording tracks on the disk surface are progressing more and more. is made of.
[0003]
On the other hand, the flying height of the slider on which the head element is mounted from the disk surface has been minimized to about 20 nm, and further reduction is required. That is, the slider is required to have a very low flying height and stable flying characteristics in which the flying height does not change depending on the peripheral speed of the disk. In order to satisfy this requirement, a technique for processing a fine, complicated and geometric air-lubricated surface with high accuracy is indispensable, and at the same time, the positional relationship with the head element must be maintained with high accuracy.
[0004]
As a technique for forming an air-lubricated surface, US Pat. No. 4,624,048, Japanese Patent Application Laid-Open No. 2-010515, and the like use a photolithography technique, that is, create a photomask corresponding to the air-lubricated surface, A method of performing etching is disclosed.
[0005]
A conventional slider having an air lubrication surface will be described in detail.
As shown in FIG. 7, the slider 1 having a substantially rectangular parallelepiped shape has a surface on which the thin film magnetic head element 2 is formed as a surface layer and an edge as a trailing surface 3 (air outflow end side), and is parallel to the trailing surface 3. The leading surface 4 is the leading surface 4 (air inflow end side), the surface where the thin film magnetic head element 2 is located in the vicinity is the air lubrication surface 6 which is uneven by the rail pattern 5, and the trailing surface 3 A conductive pattern 7 for a connection terminal for connecting the magnetic head element 2 to a head amplifier (not shown) is formed. As shown in FIG. 8, the thin-film magnetic head element 2 is formed on the substrate 8, and the upper magnetic pole 9 is on the trailing surface 3 side and is located at the longitudinal center of the trailing surface 3. .
[0006]
When manufacturing the slider 1, first, as shown in FIG. 9A, a plurality of thin film magnetic head elements 2 are formed on the surface of a ceramic substrate 8 made of AlTiC (Al ₂ O ₃ —TiC) by a wafer process. 2,... Are formed in a plurality of rows in the vertical axis direction and the horizontal axis direction with the same direction. Further, a conductive pattern 7 (see FIG. 7) is formed in the vicinity of each thin film magnetic head element 2 by a wafer process similar to that of the thin film magnetic head element 2.
[0007]
Next, as shown in FIG. 9B, the unnecessary portion of the substrate 8 at the periphery is cut away to form a rectangular magnetic head wafer 10, and further, the magnetic head wafers 10 are arranged side by side as shown in FIG. 9C. Are cut into strip-shaped rows 11, 11,. Thereafter, the stress remaining in each row 11 by the throat height process is removed by polishing.
[0008]
In each row 11, the surface on which the thin film magnetic head element 2 faces is a trailing surface forming surface (hereinafter referred to as a trailing surface) 11a, and the opposite surface is a leading surface forming surface (same leading surface) 11b. 11a and the one surface in the longitudinal direction intersecting with the leading surface 11b become an air lubrication surface forming surface (same air lubrication surface) 11c.
[0009]
Next, as shown in FIG. 10, a plurality of rows 11 are placed on a suction fixture 13 having a number of suction holes 12 so that the trailing surface 11a and the leading surface 11b are in pressure contact with each other, and air lubrication is performed. The surfaces 11c are arranged in parallel so as to block the suction holes 12, and the arranged rows 11 are vacuum-sucked on the suction fixing jig 13 by a vacuum pump (not shown). Then, the row fixing jig 15 coated with the sheet-like adhesive 14 is brought into contact with the surface opposite to the air-lubricated surface 11c of the row 11 sucked by vacuum.
[0010]
In this state, that is, in the state shown in the cross section of FIG. 11A, the row fixing jig 15 is heated to 110 ° C. and then cooled to 20 ° C. to cure the adhesive 14. After the adhesive 14 is cured, the vacuum suction is released, and the suction fixing jig 13 is removed, so that the plurality of rows 11 are warped on the row fixing jig 15 as shown in FIG. It is obtained in a state where the bend and the level difference of the air lubrication surface 11c between each row 11 are corrected.
[0011]
Next, as shown in FIG. 12A, a photosensitive resin film 16 such as a resist or dry film is applied to the air lubrication surfaces 11c, 11c,... Of the rows 11, 11,. Adhere. Thereafter, a photomask 18 on which a rail pattern 17 having a predetermined shape is formed is disposed above the rows 11, 11,..., And the upper portion of the thin film magnetic head element 2 positioned at the center is sequentially arranged for each row 11. The photomask 18 is aligned using the magnetic pole 9 (see FIG. 8) as a marker, and the photosensitive resin film 16 is exposed by irradiating light such as ultraviolet rays.
[0012]
After the exposure to all the rows 11 is completed, the rows 11, 11,... Are dipped in a developing solution together with the row fixing jig 15, and the photosensitive resin film 16 in a portion not exposed to light is dissolved in the developing solution. As shown in FIG. 12B, rows 11, 11,... Having predetermined mask patterns 19, 19,... Formed on the air lubrication surface 11c are obtained.
[0013]
Next, the rows 11, 11,... Are etched using an ion beam etching apparatus or the like to remove the air lubricated surface 11 c where the mask patterns 19, 19,. After that, the rows 11, 11,... Are washed with a cleaning solution to remove the mask patterns 19, 19,..., Thereby corresponding to the mask patterns 19, 19,. A row 11 in which a rail pattern 20 having a predetermined shape is formed on the air lubrication surface 11c is obtained independently.
[0014]
Finally, each row 11 is cut for each thin film magnetic head element 2 to obtain the slider 1 having the stepped air-lubricated surface 6 formed by the rail pattern 5 as previously described with reference to FIG. . In order to form the air lubrication surface 6 having a plurality of steps, the steps of FIGS. 12A and 12B are repeated.
[0015]
[Problems to be solved by the invention]
However, when the air lubrication surface 6 is formed as in the conventional slider processing method described above, the upper magnetic pole 9 of the thin film magnetic head element 2 is used as a position reference so that the distance from this position reference becomes a set value. When shape processing is performed, a groove portion 21 may be formed at the air inflow end due to variations in slider length (wafer thickness). However, the air-lubricating surface 6 is desirably shaped so that there is no step at the air inflow end so that the slider 1 maintains a constant pitch angle in the range from the inner periphery to the outer periphery of the disk. If the groove width varies, the amount of air flowing into the air lubrication surface 6 is changed, and the flying height variation of the slider 1 is caused.
[0016]
In order to suppress the flying height variation due to the variation in the length of the groove portion, in order to design and process the groove portion 21 not to be provided at the air inflow end, the photomask 18 is adjusted to the maximum slider length tolerance. In this case, if the slider length is short, there is a problem that the vicinity of the air outflow end of the adjacent row 11 is exposed, developed and etched.
[0017]
In order to prevent this, a spacer or a dummy bar is currently arranged between adjacent rows 11, but in addition to taking time and effort, there is no dummy bar when sandwiching the dummy bar. Compared to the case, only half of the rows 11 can be put, and the processing capability is halved. Even when a spacer is sandwiched, in order to process a rigid spacer with high accuracy, the spacer itself needs to have a thickness of several hundreds of μm, and the processing capability is reduced. Further, since the spacer itself is also etched, it cannot be used many times, and the cost for the spacer becomes high.
[0018]
The present invention solves the above-described problem. When a wafer having a plurality of head elements formed thereon is cut and an air-lubricated surface is formed on the cut surface by a photolithographic method, the air flows into the air-lubricated surface. It is an object of the present invention to provide a slider processing method capable of processing a shape with high accuracy without causing a step at an end and exposing the cut surfaces of adjacent cut wafers.
[0019]
[Means for Solving the Problems]
The present invention for solving the above-f head element and a certain direction of the wafer formed in a plurality of rows along the vertical axis direction and horizontal direction on one surface of the gold pad of the electric connection as a pair The row after cutting is arranged so that the surface having the head element and the back surface opposite to the row are adjacent to each other, and one of the exposed cut surfaces is masked for each row. In the slider processing method for manufacturing the slider having the head element and the gold pad on the trailing surface by forming the uneven air-lubricated surface for each element by photolithography technology to be exposed, and cutting each element . advance on the one surface of the wafer before the cutting, and characterized by providing a protrusion other than the gold pad to form a gap between the two sides in contact with the adjacent surfaces during the sequence of said row That.
[0020]
According to this configuration, even if the wafer thickness (and thus the cut surface width) varies, one side of the photomask pattern is aligned with respect to each row of cut wafers using a predetermined portion of the head element as a position reference. Sometimes it is possible to position the other side of the pattern in the gap due to the protrusion. Therefore, it is possible to prevent unnecessary grooves from being formed at the air inflow end away from the head element, or to expose the cut wafers arranged next to each other, and shape processing can be performed with high accuracy. Therefore, the flying height variation of the slider due to the processing error can be suppressed.
[0021]
According to the present invention, in the above-described slider processing method, the head elements formed on the surface are cut into wafers formed in a plurality of rows along the vertical axis direction and the horizontal axis direction, and the cut wafers are arranged and cut. After the air lubrication surface is formed on the surface, each element is cut.
[0022]
According to this configuration, since it is only necessary to arrange long cut wafers corresponding to the side-by-side element rows, in addition to arranging the wafer cut for each element, in addition to being able to suppress the positional deviation at the time of arrangement, Arrangement work is easy.
[0023]
Furthermore, the present invention is characterized in that, in any of the above-described slider processing methods, the protrusion is formed at a position where it is not cut, so that the cross-section of the protrusion is flush with the air lubrication surface. It is possible to prevent the air flow from being affected when the slider is used.
[0024]
Protrusions for example, arranged in wafer table layers than the head element. Thereby, it becomes possible to form by a wafer process, and formation is easy compared with formation to a lower surface.
[0025]
In addition, as the protrusion, a head element and a connection terminal pad for connecting the head and the head amplifier are used. Thereby, the connection terminal pad can also have a role of forming a gap.
[0026]
Desirably, the protrusion is formed with a protrusion height larger than the thickness tolerance of the wafer. Desirably, the protrusion is formed at a protrusion height that absorbs the alignment error of the photomask.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
1 is a perspective view of a slider manufactured in Embodiment 1 of the present invention, FIG. 2 is a partially enlarged cross-sectional view of a thin film magnetic head of a magnetic head wafer used for manufacturing the slider, and FIG. 3 is a slider from the magnetic head wafer. It is explanatory drawing which shows the photolithographic process of forming.
[0028]
In FIG. 1, a substantially rectangular parallelepiped slider 1 is configured in substantially the same manner as the conventional one described above with reference to FIG. 7, and the surface on which the thin film magnetic head element 2 is formed on the surface and on the edge is a tray. The ring surface 3 (air outflow end side), the surface parallel to the trailing surface 3 is the leading surface 4 (air inflow end side), and the surface on which the thin film magnetic head element 2 is located is uneven by the rail pattern 5 A plurality of gold pads 7a are formed on the trailing surface 3 as conductive patterns to be connected to the head amplifier. Further, a projection 22 described later is formed at the center of the trailing surface 3 and between the plurality of gold pads 7a.
[0029]
The rail pattern 5 has a rectangular area that surrounds the thin film magnetic head element 2 and a reading that surrounds the rectangular area at intervals so that the slider 1 maintains a constant pitch angle in the range from the inner periphery to the outer periphery of the disk. It is designed so that a substantially U-shaped region disposed at the end on the surface 4 side protrudes.
[0030]
As shown in part in FIG. 2, the magnetic head wafer 10 is configured in the same manner as a conventional one, and a plurality of thin film magnetic heads are formed on the surface of a ceramic substrate 8 made of AlTiC (Al ₂ O ₃ —TiC). The elements 2, 2,... Are formed in a plurality of rows along the vertical axis and the horizontal axis in the same direction by the wafer process, and the gold pad 7a is formed in the vicinity of each thin film magnetic head element 2. The magnetic head element 2 is formed by the same wafer process. Then, a projection 22 mainly composed of Al ₂ O ₃ is formed by film formation above the upper magnetic pole 9 of each thin film magnetic head element 2.
[0031]
Specifically, an insulating layer 23 made of Al ₂ O ₃ or the like is formed on the upper surface of the substrate 1, and a lower shield layer 24 made of a soft magnetic material such as permalloy is formed on the upper surface of the insulating layer 23. It is filmed.
[0032]
The reproducing head element unit 25 is disposed above the lower shield layer 24 with a space therebetween, the vertical bias layer 26 is formed on both sides of the reproducing head element unit 25, and the electrode lead layer 27 is formed on the upper surface of the vertical bias layer 26. A common shield layer 28 made of the same soft magnetic material as that of the lower shield layer 3 is formed at a distance above the read head element portion 25 and the electrode lead layer 27, thus forming the read head portion. Yes.
[0033]
An upper magnetic pole 9 made of a soft magnetic material is provided above the common shield layer 28 at an interval, and a winding coil (not shown) is provided around the upper magnetic pole 9, and recording is performed. A head portion is configured.
[0034]
The layers above the insulating layer 23, the element portion, and the magnetic pole are filled with a nonmagnetic insulating material such as Al ₂ O ₃ , and between the lower shield layer 24, the read head element portion 25, and the longitudinal bias layer 26. The lower gap insulating portion 29, the reproducing head element portion 25, the electrode lead layer 27 and the common shield layer 28 are the upper gap insulating portion 30, and the common shield layer 28 and the upper magnetic pole 9 are the recording gap layer 31. ing.
[0035]
The plurality of gold pads 7a and the protrusions 22 are formed on the upper surface of the insulating layer 32 made of this nonmagnetic insulating material. The electrode pad layer 26 and a winding coil (not shown) are connected to the gold pad 7a.
[0036]
Here, the substrate 8 has a thickness L1 = 1200 μm +/− 5 μm, and the protrusion 22 has a height L2 = 20 μm. The height L2 of the protrusion 22 is set to 10 μm or more from the viewpoint that it is desirable to be higher than the tolerance of the thickness L1 of the substrate 8, and is determined in consideration of misalignment of the photomask. The distance L3 from the upper magnetic pole 9 to the leading surface is 1210 +/− 5 μm.
[0037]
In order to process the slider 1 from such a magnetic head wafer 10, the rectangular magnetic head wafer 10 is formed into strip-shaped rows 11, 11,... In the same manner as the conventional processing method (see FIGS. 9 to 12). Each row 11 is arranged in a pressure contact state so that the trailing surface 11a and the leading surface 11b are adjacent to each other. Then, a row fixing jig 15 provided with a sheet-like adhesive 14 is disposed on the surface opposite to the air lubrication surface 11c of the arranged rows 11, 11,..., And the row fixing treatment is performed after the adhesive 14 is cured. By turning the tool 15 upside down, a plurality of rows 11, 11,... Are obtained on the row fixing jig 15 with the level difference of the air lubrication surface 11 c between the rows 11 corrected.
[0038]
As shown in FIGS. 3A and 3B from above and from the side, a plurality of rows 11 sliced and arranged from the magnetic head wafer 10 and subjected to the photolithography process as described above are adjacent to each other. The plurality of protrusions 22 of the trailing surface 11a of the row 11 are pressed against the leading surface 11b of the other row 11, and the warpage and bending of each row 11 are corrected by the projection 22 and each row 11 is corrected. A gap G having a width L4 corresponding to the height L2 of the protrusion 22 is formed therebetween.
[0039]
Therefore, a photomask (not shown) having a distance from the upper magnetic pole 9 to the leading surface 11b of 1215 μm is used, and the pattern of the photomask is used for each row 11 with the upper magnetic pole 9 as a position reference. When the position of one end of the pattern is aligned, the distance L3 from the upper magnetic pole 9 of each row 11 to the leading surface 11b is 1210 +/− 5 μm (1205 μm to 1215 μm) as described above. It coincides with the end (leading surface 11b) or is located in the gap G.
[0040]
Therefore, the groove portion is not formed at the air inflow end portion, and the air lubrication surface 11c of the adjacent row 11 is not etched by the exposure, development and etching.
[0041]
Accordingly, by cutting each row 11 that has been etched for each thin film magnetic head element 2, the slider 1 having the air lubrication surface 6 having no step at the air inflow end as shown in FIG. 1 is obtained.
[0042]
As described above, by forming the protrusion 22 on the magnetic head wafer 10 that is higher than the tolerance of the substrate thickness (substantially equal to the wafer thickness), in the photolithography process of the air lubrication surface 6, the air inflow end is conventionally provided. Thus, it is possible to process the shape without forming the groove portion and without exposing, developing, and etching the air lubricated surface 11c of the adjacent row 11, and the slider caused by variations in the slider length (wafer thickness). 1 variation in flying height can be suppressed.
[0043]
Note that the protrusion height L2 of the protrusion 22 can be reduced by using the substrate 8 having a small thickness variation, but the protrusion height of 5 μm or more is secured in consideration of the alignment accuracy of the photomask. It is desirable to do. More desirably, the protrusion height is 10 μm or more, and further desirably, the protrusion height is 15 μm or more.
[0044]
The protrusion 22 is preferably formed at a position that is not cut by the slicing process of the row 11. By forming the protrusion 22 in this manner, the cross section of the protrusion 22 in the slider 1 is flush with the air lubrication surface 6. By avoiding this, it is possible to prevent the air flow from being affected when the slider 1 is used.
[0045]
The main component of the protrusion 22 is Al ₂ O _{3 in the} first embodiment. However, the protrusion 22 is not limited to Al ₂ O ₃ as long as a desired protrusion height can be secured.
Furthermore, in the first embodiment, the protrusions 22 are formed using the film forming method, but it is only necessary that the protrusions 22 can be formed, and it is needless to say that the protrusions 22 may be formed using other methods such as bonding.
[0047]
4, 5 and 6 show reference examples. The slider 1 and the magnetic head wafer 10 are configured in the same manner as in the first embodiment. However, unlike the first embodiment, the protrusion 22 is not formed, and the height L5 of the gold pad 17a is 20 μm. Is formed.
[0048]
The height L5 of the gold pad 17a is determined to be 10 μm or more from the viewpoint that it is preferably higher than the tolerance of the thickness L1 of the substrate 8, and is determined from the viewpoint that 15 μm or more is preferable in consideration of photomask alignment.
[0049]
A plurality of rows 11 sliced and arranged from the magnetic head wafer 10 and subjected to a photolithography process are shown in FIGS. 6 (a) and 6 (b). A plurality of gold pads 17 a on the trailing surface 11 a are in pressure contact with the leading surface 11 b of the other row 11, and the warpage and bending of each row 11 are corrected by the gold pad 17 a, and the gold pads are interposed between the rows 11. A gap G having a width L6 corresponding to the height L5 of 17a is formed.
[0050]
For this reason, when the same photomask as in the first embodiment is used and one end of the pattern of the photomask is aligned with respect to each row 11 using the upper magnetic pole 9 as a position reference, the other end of the pattern flows into the air. It coincides with the end (leading surface 11b) or is located in the gap G.
[0051]
Therefore, the conventional groove portion is not formed at the air inflow end portion, and the air lubrication surface 11c of the adjacent row 11 is not etched by the exposure, development and etching.
[0052]
Therefore, by cutting each etched row 11 for each thin film magnetic head element 2, a slider 1 having an air lubrication surface 6 without a step at the air inflow end as shown in FIG. 4 is obtained.
[0053]
As described above, the gold pad 17a is formed on the magnetic head wafer 10 so as to be higher than the tolerance of the substrate thickness (substantially equal to the wafer thickness). It is possible to process the shape without forming a portion and without exposing, developing and etching the air lubricated surface 11c of the adjacent row 11, and the flying height of the slider 1 due to variations in the slider length (wafer thickness) Variations can be suppressed.
[0054]
Although it is possible to reduce the height L5 of the gold pad 17 by using the substrate 8 having a small thickness variation, it is desirable to secure a height of 5 μm or more in consideration of the alignment accuracy of the photomask. . More desirably, the protrusion height is 10 μm or more, and further desirably, the protrusion height is 15 μm or more.
[0055]
In the first embodiment described above, the air bearing surface 6 of the slider 1 which includes a thin-film magnetic head element 2 described in mind that formed by dry etching, the present invention is, or a thin film magnetic head element, dry The present invention is not limited to the photolithography technique using etching, but is useful for all slider processing in which the air-lubricated surface facing the recording medium is processed by the photolithography technique. For example, the head may be an optical head, the etching may be wet etching, and the resist may be a liquid resist.
[0056]
【The invention's effect】
According to the present invention as described above, the spacer by forming a collision raised portion on the wafer surface in the wafer process, in the photolithography process of the air bearing surface for performing slicing the wafer and array, the protrusions It is allowed to act as, without causing unnecessary step in the air inlet end portion, or adjacent exposure interleaf cormorants element row (row), development, without etching, can be accurately shape processing. Thus, the plurality of sliders obtained by cutting each element row for each head element, it is possible to suppress flying height variations caused by variations slider length (wafer thickness).
[Brief description of the drawings]
FIG. 1 is a perspective view of a slider formed by the method of Embodiment 1 of the present invention. FIG. 2 is a partially enlarged sectional view of a thin film magnetic head element portion of a magnetic head wafer used for forming the slider of FIG. FIG. 4 is a perspective view of a slider formed by the method of the reference example . FIG. 5 is used for forming the slider of FIG. FIG. 6 is a partially enlarged sectional view of a thin film magnetic head element portion of a magnetic head wafer. FIG. 6 is an explanatory view showing a photolithography process for forming the slider of FIG. 4 from the magnetic head wafer of FIG. 8 is a partially enlarged sectional view showing a thin film magnetic head element portion of the slider shown in FIG. 7. FIG. 9 is an explanatory view showing a slicing process for forming the slider shown in FIG. 7 from the magnetic head wafer. FIG. 11 is an explanatory diagram showing a row alignment process for forming the slider of FIG. 7 from a magnetic wafer. FIG. 11 is an explanatory diagram showing a row bonding process for forming the slider of FIG. 7 from a magnetic head wafer. Showing the photolithography process for forming the film
DESCRIPTION OF SYMBOLS 1 Slider 2 Thin film magnetic head element 4 Air lubrication surface 7a Gold pad (pad for connection terminal)
8 Board
10 Magnetic head wafer
11 Raw (cut wafer)
11c Air lubrication surface forming surface (cut surface)
18 Photomask
22 Protrusion G Gap L1 Slider length (substrate thickness)
L2 Projection height L4 Gap width L5 Gold pad height L6 Gap width

Claims (3)

F head element and along one surface and the vertical axis direction and horizontal direction of gold pads of the electric connection as a pair cutting the wafer formed in a plurality of rows every predetermined direction of the element row, after cutting Rows are arranged so that the surface having the head element and the back surface opposite to the row are adjacent to each other, and the concavo-convex shape of each element is formed by photolithography technology in which one of the exposed cut surfaces is masked and exposed for each row. In the slider processing method for manufacturing the slider having the head element and the gold pad on the trailing surface by cutting each element after forming the air lubrication surface,
A method of processing a slider, wherein a protrusion other than the gold pad is formed on the one surface of the wafer before cutting so as to contact a surface adjacent to the row when the rows are arranged to form a gap between both surfaces. The slider processing method according to claim 1, wherein the protrusion is formed at a position where the protrusion is not cut. Slider processing method according to claim 1 or claim 2, characterized in that placing the projecting portion, the wafer table layers than the head element.

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