JP2001297408A - Method for manufacturing thin film magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thin film magnetic head, whereby yield is improved by preventing the occurrence of cracking in the manufacturing process of a head chip. SOLUTION: Crack preventing areas 7 are formed in the plural position of the surface direction of a thin film device layer 2 formed by laminating a device part through an insulating interlayer film, a full cutting groove 4 for cutting out a head chip by crossing the thin film device layer 2 is formed such that the starting point 41 and the end point are positioned in the forming region of the crack preventing area 7. The crack preventing area 7 is constructed by burying a metallic material in a circle range around the starting point 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a thin film magnetic head, and more particularly, to a method of effectively preventing cracks in a head chip manufacturing process.

[0002]

2. Description of the Related Art A thin-film magnetic head has a thin-film head chip bonded and supported to the tip of a support arm. The head chip is formed on a circular ceramic substrate 1 of AlTiC or the like as shown in FIG. Is cut out from the thin film device layer 2 formed by lamination. That is, the thin film device layer 2 sequentially forms device portions 31 to 33 (FIG. 7) constituting a yoke of a NiFe material, a coil or lead wire of a Cu material, a wiring connection pad of an Au material, and the like by a photolithography process. These device portions 31 to 33 are laminated while being insulated from each other by insulating interlayer films 21 to 24 made of alumina. The thin film device layer 2 traverses the entire cutting grooves 4 (from the separation layer 11 to the substrate 1). 25m according to FIG.
The sheet is cut into a large number of device sheets 6 (FIG. 6) of a square shape in a grid pattern.

As shown in FIG. 9, a plurality of strips 61 are formed in each device sheet 6 by means of broken lines.
And a plurality of trapezoidal head chips are formed by the semi-cut grooves 5 (FIG. 8B) which are formed in parallel so as to intersect the entire cut grooves 4 and do not reach the separation layer 11. CH. Such a substrate 1 is immersed in an etching bath, and the etching solution is passed through the entire kerf 4 and the separation layer 11.
The device sheets 6 are separated from the substrate 1 by invading and dissolving them. The peeled device sheet 6 is stuck on an adhesive tape, is broken along the half cut groove 5 by a jig, and is separated into a single head chip CH.

[0004]

In such a conventional manufacturing method, the device sheet 6 peeled off from the substrate 1 is used.
There is a problem that the device sheet 6 is liable to crack when cleaning or the like.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a method of manufacturing a thin film magnetic head in which a crack is prevented from occurring in a manufacturing process of a head chip and the yield is improved. I do.

[0006]

According to the inventors' experiments,
Many of the cracks in the device sheet 6 occur from the start point 41 and the end point 42 (FIG. 9) of the entire kerf 4. As a cause thereof, when forming the full kerf 4 and the half kerf 5 with a laser beam, minute cracks 43 and 53 are often generated around the groove due to thermal shock or processing distortion (FIG. 8). At the starting point 41 and the ending point 42 of the kerf 4, the laser power is concentrated and cracks 43 are likely to occur. In addition, the starting point 41 and the ending point 42 become supporting points of the strips 61 (FIG. 9) after being peeled off from the substrate 1, so that stress is concentrated on these parts due to external force applied during cleaning or the like. Starting point 41
The crack 43 generated in the device sheet 6 extends in the thickness direction of the device sheet 6 and becomes a crack.

Therefore, the present invention has been made based on the above considerations, and a thin-film device layer (2) formed by laminating device portions (31-33) via insulating interlayer films (21-24). Crack prevention areas at multiple positions in the plane direction (7)
Are formed, and all the kerfs (4) for cutting out the head chip (CH) across the thin-film device layer (2) are formed at the start point (41) and the end point in the formation area of the crack prevention area (7), respectively. A part (42) is located and formed. Here, the crack prevention region (7) can be formed by burying a metal material within a predetermined range in at least one layer in the thickness direction of the thin film device layer (2). The cracks (43) extending in the thickness direction of the thin film device layer (2), that is, the device sheet (6), from the groove surface of the total kerf (4).
Is within a range that can be blocked.

In the present invention, a crack preventing region is formed in the thin film device layer, and the entire kerf is formed by locating the start point and the end point in the formation region of the split preventing region. Is prevented, or even if a crack occurs, it is prevented from extending in the thickness direction of the device sheet, and the device sheet is prevented from cracking.

In the device sheet (6) manufactured in the manufacturing process of the present invention, crack preventing regions (7) are formed at a plurality of positions in the plane direction, and formed to separate the head chip (CH). The starting point (41) and the ending point (42) of the entire kerf (4) are located in the formation area of the crack prevention area (7).

[0010] The reference numerals in parentheses indicate the correspondence with specific means described in the embodiment described later.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is an enlarged horizontal sectional view of a starting point 41 of an entire kerf 4 crossing each device sheet 6 (FIG. 9) in a thin film device layer. FIG.
Shows a vertical sectional view thereof. A crack preventing region 7 (FIG. 1), which is circular in plan view, is formed at the starting point 41 of the entire kerf 4. The crack preventing region 7 penetrates the thin film device layer 2 in the thickness direction and separates the separation layer from the surface. No. 11 (FIG. 2). The crack prevention region 7 is made of a metal material. For example, the above-described NiFe material, Cu material, Au material, or the like constituting the device portions 31 to 33 (FIG. 7) is provided in each of the interlayer films 21 to 24 in the device portions. 31 to 33 are formed at the same time as the etching formation to form a laminated columnar crack prevention region 7. Note that a different metal material may be used for each layer.

When the thin film device layer 2 is formed on the substrate 1, each of the device sheets 6
The start point 41 and the end point 42 of the entire kerf 4 in FIG. 9 are all formed in advance at the same time. Then, the irradiation of the laser beam is started in the formation region of the crack prevention region 7 serving as the start point portion 41, and the laser beam is traversed along the entire polygonal kerf 4 reaching the separation layer 11. This ends within the formation region of the crack prevention region 7 which becomes

In this manner, the starting point 41 of the entire kerf 4
Since the end point portion 42 and the end point portion 42 are both located in the formation region of the crack prevention region 7 made of a metal material, the crack 43 (FIG. 8) does not occur even if the laser power is concentrated here. . Therefore, even if stress is concentrated on the starting point 41 and the ending point 42 serving as support points of the strips 61 (FIG. 9) of the device sheet 6 peeled off from the substrate 1, even if stress is concentrated by an external force during cleaning or the like, the device sheet 6 is broken. Does not occur.

(Second Embodiment) The crack preventing region 7 is a starting point 41 and an ending point 42 of the entire kerf 4 and, as shown in FIG. 3, the lowermost interlayer film of the thin film device layer 2 which is in contact with the separation layer 11. 21 may be formed only. In this case, a crack 43 extending from the groove surface of the entire kerf 4 occurs in the other interlayer films 22 to 24 of the thin film device layer 2 as shown in the drawing. If the crack prevention region 7 is formed with a diameter D of about 100 μm with respect to the width d = 25 μm, a crack 43 grows in the thickness direction in the thin film device layer 2 or in the device sheet 6 peeled off from the substrate 1. However, the progress is stopped in the crack prevention area 7 on the way, and the device sheet 6 is not broken.

If the crack preventing region 7 is formed in the interlayer film 21 at the lowermost position, the starting point 41 and the ending point 42 of the entire kerf 4 can be used to form the kerf 4 with a laser beam. Can be prevented from being crosslinked between the substrate 1 and the thin film device layer 2, so that the device sheet 6 can be smoothly separated from the substrate 1.

(Third Embodiment) The crack prevention region 7 is formed at the start point 41 and the end point 42 of the entire kerf 4 and only in the uppermost interlayer film 24 of the thin film device layer 2 as shown in FIG. be able to. In this case, a crack 43 extending from the groove surface of the entire kerf 4 occurs as shown in the other interlayer films 21 to 23 of the thin film device layer 2, but the width d of the entire kerf 4 is 2
If the crack prevention region 7 is formed with a diameter D of about 100 μm for 5 μm, even if the crack 43 grows in the thickness direction in the thin film device layer 2 or the device sheet 6 separated from the substrate 1, Of the device sheet 6 is prevented in the crack prevention region 7 of the device sheet.

(Fourth Embodiment) The crack preventing region 7 is not limited to the lowermost interlayer film 21 or the uppermost interlayer film 24 of the thin film device layer 2, but as shown in FIG.
2 and may be thinner than the thickness of the interlayer film 22 as shown in the figure. Also in this case, the crack prevention area 7
Outside the formation region, a crack 43 extending from the groove surface of the entire kerf 4 occurs in each of the interlayer films 21 to 24, but the width d of the entire kerf 4 is 2
If the crack prevention region 7 is formed with a diameter D of about 100 μm for 5 μm, even if the crack 43 grows in the thickness direction in the thin film device layer 2 or the device sheet 6 separated from the substrate 1, Of the device sheet 6 is prevented in the crack prevention area 7 of the device sheet 6.

(Other Embodiments) The formation region of the crack prevention region does not necessarily have to be circular. However, considering that the laser power reaches equidistantly around the laser beam incident point, it is preferable to make it circular. . Further, the crack preventing region may be formed in arbitrary plural layers in the thickness direction of the thin film device layer at the start point and the end point of the entire kerf.

[0019]

As described above, according to the method of manufacturing a thin-film magnetic head of the present invention, it is possible to effectively prevent the occurrence of cracks in the process of manufacturing a head chip and to improve the yield.

[Brief description of the drawings]

FIG. 1 is a horizontal cross-sectional view showing a first embodiment of the present invention, in which a starting point portion of all kerfs is enlarged.

FIG. 2 is an enlarged vertical sectional view of a starting point portion of all kerfs.

FIG. 3 is a vertical cross-sectional view showing a second embodiment of the present invention, in which a starting point portion of all kerfs is enlarged.

FIG. 4 is a vertical cross-sectional view showing a third embodiment of the present invention, in which the starting point of all kerfs is enlarged.

FIG. 5 is a vertical cross-sectional view showing a fourth embodiment of the present invention, in which the starting point of all kerfs is enlarged.

FIG. 6 is an overall plan view of a substrate explaining a conventional technique.

FIG. 7 is a vertical sectional view of a thin film device layer formed on a substrate.

FIG. 8 is a vertical sectional view of a full kerf and a half kerf formed in a thin film device layer.

FIG. 9 is an enlarged plan view of a device sheet.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Substrate, 2 ... Thin film device layer, 21, 22, 23, 2
DESCRIPTION OF SYMBOLS 4 ... Interlayer film, 31, 32, 33 ... Device part, 4 ... All kerfs, 41 ... Start point part, 42 ... End point part, 43 ... Crack, 6
... device sheet, 7 ... crack prevention area, CH ... head chip.

Claims (2)

[Claims] 1. A crack prevention region is formed at a plurality of positions in a plane direction of a thin film device layer formed by stacking device portions with an insulating interlayer film interposed therebetween, and a head chip is cut out across the thin film device layer. A thin-film magnetic head, wherein all the kerfs are formed in the formation region of the crack prevention region, with the start point and the end point thereof positioned. 2. The method of manufacturing a thin-film magnetic head according to claim 1, wherein the crack preventing region is formed by burying a metal material within a predetermined range in at least one layer in a thickness direction of the thin-film device layer. .