JP2004246987A - Wafer structure for forming element, manufacturing method of element, magnetic recording head, and magnetic disk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wafer structure in which length of a major side of a floating plane can be designed short in manufacturing a magnetic recording head, back abrasion of a wafer is not required, and quantity of mud caused by abrasion can be reduced largely. <P>SOLUTION: This structure comprises a wafer for forming element having thickness corresponding to either of thickness or width of a substrate of an element and a supporting wafer which is stuck to a back side of the wafer for forming element through a junction layer, and the junction layer consists of a hardened matter of a resin material formed all over the surface at either of the back of the wafer for forming element and the surface of the supporting wafer with the prescribed film thickness, and has a groove shape pattern. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wafer bonding technique, and more particularly to a device-forming wafer structure useful for manufacturing a magnetic recording head of a magnetic disk device as an information recording device. The present invention also relates to a method for manufacturing an element such as a magnetic recording head using such a wafer structure, and a magnetic recording head and a magnetic disk drive.
[0002]
[Prior art]
With the development of information processing technology, there is an increasing demand for higher recording densities for magnetic disk devices used for external recording devices of computers. To meet this demand, for example, in the reproducing head of a magnetic disk device, a magnetoresistive element using a magnetoresistive element whose electric resistance changes according to the strength of a magnetic field is used instead of the conventional wound inductive thin film magnetic head. A mold head, that is, an MR head has been used. The MR head has features such as a reproduction output width several times larger than that of the conventional inductive thin film magnetic head, a small inductance, and a large S / N ratio can be expected. In addition to the MR head, an AMR head using the anisotropic magnetoresistive effect, a GMR head using the giant magnetoresistive effect, and a practical spin valve GMR head are also used. Further, the magnetic disk drive has not only increased the recording density but also has been downsized, and the mounting density has been increased. For this reason, it is necessary to reduce the size of the magnetic recording head.
[0003]
Conventional magnetic recording heads are usually manufactured by a method in which functional elements necessary for forming a plurality of magnetic recording heads are formed on a single semiconductor wafer and then cut into individual heads by dicing or the like. Reference 1). As an example of a method for manufacturing a magnetic recording head, as shown in FIG. 1, for example, ferrite, AlTiC (Al₂O₃After a large number of head element portions 24 are simultaneously formed on a wafer (substrate) 60 such as -TiC) by a thin film technique in a matrix form, and finally cut one by one along cutting lines 28 and 29, A thin-film magnetic recording head described below with reference to FIG. 9 and the like is completed. The head element section 24 can be separated by various methods. In general, the substrate 60 is first cut and separated by a dicer or the like at the position of the cutting line 28 in the horizontal direction, so that the head element section 24 is separated by one. The core slider blocks 30 arranged in a row are manufactured. Next, each core slider block 30 is cut and separated individually at the position of the cutting line 29 to obtain individual head element portions 24. The cutting of the head element portion 24 from the core slider block 30 can be performed, for example, as shown in FIG.
[0004]
First, as shown in FIG. 2A, for example, an AlTiC substrate (single plate) 60 having a thickness of 2 mm is individually separated at the position of the cutting line 29 shown in FIG. In the illustrated example, a dicer having a dicing blade 62 is used. At this stage, dicing is performed so that the narrow groove 61 having a depth d is formed along the cutting line without completely separating the head element portion 24. The dicing depth d corresponds to the length of the floating surface b of the magnetic recording head, and is 1.25 mm in the case shown. The dicing interval corresponds to the width of the element surface a of the magnetic recording head in which the functional elements are formed, although the functional elements are omitted in the figure. As can be understood from the drawing, 0.75 mm of the thickness portion of the substrate 60 remains without dicing. However, if the head element portion 24 is cut off at this stage, the head element This is because the portion 24 is scattered, and a large amount of dicing powder or the like adheres to the portion 24.
[0005]
Next, as shown in FIG. 2B, the substrate 60 is fixed while the element surface a of the magnetic recording head is temporarily fixed with an adhesive tape (not shown) in order to prevent scattering of the head element part 24. Polish about 0.75 mm from the back. For this polishing operation, for example, a back polishing blade 63 as shown in the figure can be used. As shown in the figure, the head element portion 24 having the length of the floating surface b of t (1.25 mm) is obtained collectively.
[0006]
[Patent Document 1]
JP-A-8-111006 (paragraph number 0017, FIG. 5)
[0007]
[Problems to be solved by the invention]
However, the conventional method for manufacturing a magnetic recording head described above with reference to FIG. 2 has some problems to be solved.
[0008]
First, as magnetic recording heads continue to be miniaturized in the future, the length of the long side of the air bearing surface (dicing depth) will become shorter, the backside polishing amount of the wafer (substrate) will increase, and the processing time will also increase. I do. In addition, the amount of polishing sludge increases in proportion to this, so that the disposal cost increases. As a countermeasure against these problems, a method of reducing the thickness of the substrate to be used is conceivable. However, in this case, it is necessary to replace a unit of the manufacturing apparatus in accordance with the thickness of the wafer, and the increase in cost becomes another problem.
[0009]
It is therefore an object of the present invention to reduce the length of the long side of the air bearing surface in the manufacture of a magnetic recording head, thus eliminating the need for polishing the back surface of the wafer and greatly reducing the amount of sludge generated by polishing. It is another object of the present invention to provide a device-forming wafer structure capable of reusing components.
[0010]
Another object of the present invention is to provide a method for manufacturing a magnetic recording head and other elements using the wafer structure of the present invention.
[0011]
A further object of the present invention is to provide a magnetic recording head that can contribute to higher recording density, downsizing of the device, higher mounting density, and the like.
[0012]
Still another object of the present invention is to provide a magnetic disk drive which is small in size and has a high recording density and a high mounting density.
[0013]
The above and other objects of the present invention can be easily understood from the following detailed description.
[0014]
[Means for Solving the Problems]
The present invention provides an element forming wafer structure used for forming an element including a substrate and a functional element formed on the surface and / or inside the substrate on one surface thereof,
An element forming wafer having a thickness corresponding to one of the thickness and the width of the substrate, which can be formed into a plurality of the elements and can be cut into individual elements in a subsequent step,
A supporting wafer bonded to a back surface of the device forming wafer via a bonding layer, and
The bonding layer is formed of a cured product of a resin material entirely formed with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer, and has a groove pattern. A wafer structure for element formation.
[0015]
In the device formation wafer structure according to the present invention, since the device formation wafer is bonded to the support wafer after adjusting the thickness in advance, the support wafer is formed after the functional elements and the like are formed in the device formation wafer. By simply peeling off, the substrate length (or substrate thickness) required for elements such as a magnetic recording head can be easily obtained, and the backside polishing in the prior art is not required. In addition, the amount of sludge generated by polishing can be reduced. Further, since the support wafer remains intact, it can be reused for manufacturing a new device-forming wafer structure.
[0016]
In another aspect, the present invention provides a method for collectively manufacturing a plurality of elements including a substrate and a functional element formed on and / or inside the substrate, the method comprising: :
A plurality of the elements are formed, and an element forming wafer that can be cut into individual elements in a subsequent step and has a thickness corresponding to one of the thickness and the width of the substrate is manufactured. Process,
Producing a support wafer having substantially the same planar shape as the element forming wafer,
A step of forming a bonding layer made of a resin material having a groove pattern on a whole surface with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer;
Laminating the back surface of the element forming wafer and the surface of the support wafer via the bonding layer, and bonding the two by curing the resin material;
Forming a plurality of the elements by forming the functional elements according to a predetermined design on a surface of the element forming wafer; and
A step of separating the elements formed on the element forming wafer into individual elements while being supported by the support wafer
And a method for manufacturing an element.
[0017]
The element manufacturing method according to the present invention can be advantageously used for manufacturing various elements including a magnetic recording head. For example, when this method is applied to the manufacture of a magnetic recording head, after a recording element is formed on an element forming wafer, a back surface polishing step of a substrate (for example, an AlTiC substrate) which is one step of processing into a slider shape. Can be eliminated or the amount of polishing can be reduced, and a small-sized magnetic recording head can be manufactured very advantageously.
[0018]
Further, in another aspect, the present invention relates to a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
Including a substrate and a functional element formed on and / or inside the substrate; and
A magnetic recording head, which is cut out from a wafer structure for element formation according to the present invention.
[0019]
Still another aspect of the present invention is a magnetic disk drive provided with a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information. hand,
The magnetic recording head includes a substrate and a functional element formed on and / or inside the substrate, and
A magnetic disk drive cut out from a wafer structure for element formation according to the present invention.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
The wafer structure for element formation, the element manufacturing method, the magnetic recording head, and the magnetic disk drive according to the present invention can be advantageously implemented in various forms.
[0021]
The present invention firstly resides in an element forming wafer structure used for forming an element including a substrate and a functional element formed on and / or inside the substrate. Here, the "element" means a substrate (which may be a base, a support, a base, etc.) and various functional elements, for example, a semiconductor functional element (eg, an IC chip, an LSI chip, etc.), a wiring layer, an electrode, a capacitor. , A conductor, an external connection terminal, an optical functional element, an electronic functional element, and the like. Therefore, although the magnetic recording head is particularly described below as a typical example of the element, the wafer structure of the present invention is also used for manufacturing other elements such as a semiconductor device, a printed wiring board, an optical device, and an information display device. Can be applied. The functional element is usually formed on the surface or inside of the substrate, but may be formed on the back surface of the substrate if necessary.
[0022]
The device-forming wafer structure according to the present invention includes at least the following three types of elements.
(1) Device forming wafer
This wafer is for forming a plurality of devices or precursors thereof. When the element precursor is formed on the wafer, additional functional elements can be formed after the separation, and the target element can be completed. The formed element or element precursor can be cut into individual elements or element precursors by an arbitrary cutting method such as dicing in a subsequent step. Here, the thickness of the wafer is a size corresponding to either the thickness or the width of the substrate of the device to be obtained, and therefore, the back surface of the wafer is polished to adjust the thickness as in the conventional technique. There is no need for a step of forming the substrate to a desired thickness.
(2) Support wafer
As described above, since the device forming wafer has a desired thickness on the substrate, if the device or the device precursor is separated as it is, the device becomes complicated or the yield decreases. Such a problem occurs. Therefore, this support wafer is used by bonding it to the back surface of the element formation wafer via a bonding layer so that the element formation wafer can be stably and smoothly separated in the separation step.
(3) bonding layer
The bonding layer is generally disposed at a predetermined thickness on one of the back surface of the device forming wafer and the front surface of the support wafer. However, if necessary, a bonding layer may be arranged on both the back surface of the device forming wafer and the surface of the support wafer. The bonding layer imparts sufficient flatness to the surface of the wafer structure, so that inconvenience such as air entrapment should not occur when wafers are bonded to each other. It is necessary to be formed, but at the same time, it is necessary to have a groove-like pattern of the number and depth necessary to assist escape of air and the like. The bonding layer is formed from a cured resin material in consideration of the formation of the groove pattern and the like.
[0023]
FIG. 3 is a cross-sectional view showing a typical example of, but not limited to, a device-forming wafer structure according to the present invention. Hereinafter, the wafer structure of the present invention will be described in detail with reference to this.
[0024]
As shown in the figure, the device-forming wafer structure of the present invention typically comprises
A plurality of elements (not shown) that can be cut into individual elements in a later step are provided on the element surface, and have a thickness t corresponding to either the thickness or the width of the target element substrate. A device forming wafer 60,
A support wafer 70 is attached to the back surface of the element forming wafer 60 via a bonding layer 71.
[0025]
Further, the bonding layer 71 is entirely formed with a predetermined film thickness on one of the back surface of the element forming wafer 60 and the surface of the support wafer 70 (in the case of the drawing, the surface of the support wafer 70). Made of a cured resin material. The bonding layer 71 has a groove pattern 72 formed by selectively removing a part of the bonding layer 71.
[0026]
In the practice of the present invention, the element forming wafer and the support wafer can be formed of any materials according to the desired element configuration. These wafers can preferably consist of, for example, AlTiC, Si, SiC, etc. Of course, the wafer may be made of a resin material, a metal material, or the like, depending on the configuration of the target element.
[0027]
The element forming wafer and the support wafer may be made of the same material, or may be made of different materials. The support wafer that does not directly participate in the formation of the element may be made of any material as long as it has a function as a support and has sufficient strength and adhesion of the bonding layer. However, considering reuse, it is recommended to use a lightweight material to form the support wafer. As an example, both the device forming wafer and the support wafer may be formed from an AlTiC substrate, or both may be formed from a Si substrate. An excellent AlTiC may be used, and an Si substrate excellent in workability, cost, etc. may be used for the support wafer. In general, it is preferable to bond wafers of the same material, because peeling due to stress is small and a good bonding result can be obtained. When a Si substrate is used, the substrate can be attracted by an electrostatic chuck used in a semiconductor manufacturing apparatus.
[0028]
The element forming wafer and the support wafer can each have the same size as a wafer generally used for manufacturing a semiconductor device or the like. These wafers typically range in size from about 3 to 8 inches (about 7.5 to 20 cm). Further, the thickness of these wafers can be changed in a wide range according to each wafer. For example, the thickness of the device forming wafer is usually in the range of about 0.05 to 1.25 mm, and the thickness of the support wafer is usually in the range of about 0.5 to 1.7 mm. .
[0029]
Further, the element forming wafer and the support wafer are used after being subjected to a pretreatment such as surface polishing and cleaning as generally performed in the manufacture of semiconductor devices and the like. After the pretreatment, at least a part of the functional elements necessary for forming the elements is formed on the surface of the wafer (the element surface of the substrate) by using a common technique such as photolithography and etching.
[0030]
The bonding layer can bond the device forming wafer and the support wafer with sufficient strength despite the provision of the groove pattern, and as long as the properties of the obtained wafer structure are not adversely affected. It may be formed from any material. Suitable bonding layer materials include, for example, cured materials such as resin materials, paints, and adhesives. For example, a desired bonding layer having a groove pattern can be formed by printing such a bonding layer material in a predetermined pattern by screen printing or the like and curing the material.
[0031]
In the practice of the present invention, a resist material such as a photoresist, for example, can be particularly advantageously used as a bonding layer material in view of film formability, handleability, workability of a groove pattern, and the like. Here, the resist material is used as the bonding layer material because a very good film thickness uniformity can be obtained by a coating method such as spin coating, and the applied resist material is exposed and developed so that the bonding surface at the time of bonding is used. This is because a groove-like pattern can be easily formed on the entire surface of the application surface to prevent gas from being trapped.
[0032]
Although the formation of the bonding layer using the resist material can be performed by various methods, it is generally performed by performing pattern exposure and development on the film of the resist material according to the groove pattern. preferable. The exposure and development steps can be carried out by any conventional method depending on the resist material used.
[0033]
The resist material used for forming the bonding layer is not particularly limited. For example, a resist material sensitive to various kinds of light such as ultraviolet rays, infrared rays, electron beams, and laser beams can be advantageously used. Such resist materials are not limited to those listed below, but include, for example, novolak resins, silicon-containing resins, and epoxy resins. Since these resist materials are described in detail in patent documents and the like, refer to the corresponding documents for details.
[0034]
For example, when an element such as a magnetic recording head is manufactured, if there is no step of raising the temperature to 230 ° C. or more in the manufacturing process, a positive resin having a novolak resin having thermoplasticity and good adhesiveness as a base resin is used. It is effective at low cost to use a mold photoresist.
[0035]
In addition, when there is a step of a high temperature of 230 ° C. or more in the manufacturing process of the magnetic recording element, it is effective to use a silicon-containing resin having good heat resistance, although the material cost is increased. There is no problem in particular if the resist is made of a silicon-containing resin. In particular, when a resist made of a silicon-containing polymer is used as a base resin (see JP-A-11-130860), good heat resistance and lamination are obtained. Sex can be obtained at the same time.
[0036]
When a resist material is used as a bonding layer material, after forming a resist film having a groove pattern, the device forming wafer and the support wafer are bonded by heating and reflowing the resist film. It is preferable to adopt a method in which after performing a whole-surface exposure on the resist film having the above, the device forming wafer and the support wafer are bonded by heating and reflowing further. Exposure of the entire surface after the formation of the groove pattern is effective in suppressing decomposition and degassing of the photosensitive group in the resist during heating reflow.
[0037]
When a resist material is used as a bonding layer material, after forming a resist film having a groove pattern, the device forming wafer and the support wafer are bonded by heating and reflowing the resist film. It is preferable to adopt a method in which after performing a whole-surface exposure on the resist film having the above, the device forming wafer and the support wafer are bonded by heating and reflowing further.
[0038]
Further, the thickness of the bonding layer formed from a resist material or another material can be changed in a wide range. The thickness of the bonding layer is usually in the range of about 300 to 10,000 nm, and more preferably in the range of about 1,000 to 5,000 nm. If the thickness of the bonding layer is too small, inconveniences such as damage and breakage may occur when individual elements are cut out from the wafer.
[0039]
Furthermore, the groove-like pattern formed on the surface of the bonding layer is not particularly limited, and may be any pattern as long as it is a pattern that can secure a discharge path for gas generated during film formation. Suitable groove-like patterns include, for example, lattice-like, stripe-like, and dot-like patterns. For example, the groove-shaped pattern may be a lattice-shaped groove-shaped pattern 72 as shown in FIG. 5, or may be a stripe-shaped groove-shaped pattern 72 as shown in FIG. In these groove patterns, the width of the groove is usually in the range of about 10,000 to 500,000 nm, and the depth of the groove is usually the thickness of the bonding layer. The pitch of the groove pattern is usually about 500 to 5,000 μm.
[0040]
Although it was not expected at all, in the case of the wafer structure for element formation of the present invention, the surface is excellent and excellent even though the support wafer and the bonding layer are used together as described above. Have a degree. That is, the flatness of the wafer structure is 1 μm / cm or less when expressed by the amount of warpage measured on the surface of the device forming wafer after bonding, and is generally about 1 to 2 μm / cm. Range. When the amount of warpage of the wafer structure is at such a low level, when patterning is performed on the wafer structure or a substrate obtained from the wafer structure, fineness of 0.2 μm or less can be achieved without causing a problem in focus adjustment with a stepper. Line patterns can be accurately formed.
[0041]
Since the wafer structure for element formation of the present invention has the above-mentioned surface flatness and other excellent characteristics, a large number of such elements are used in the manufacture of magnetic recording heads, other elements, devices and the like specifically described below. It can be used advantageously as a source of substrate for the sample.
[0042]
Second, the present invention resides in a method for collectively manufacturing a substrate and a plurality of elements including a functional element formed on the surface and / or inside the substrate, for example, a magnetic recording head. The device manufacturing method according to the present invention includes the following steps:
A plurality of the elements are formed, and an element forming wafer that can be cut into individual elements in a subsequent step and has a thickness corresponding to one of the thickness and the width of the substrate is manufactured. Process,
Producing a support wafer having substantially the same planar shape as the element forming wafer,
A step of forming a bonding layer made of a resin material having a groove pattern on a whole surface with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer;
Laminating the back surface of the element forming wafer and the surface of the support wafer via the bonding layer, and bonding the two by curing the resin material;
Forming a plurality of the elements by forming the functional elements according to a predetermined design on a surface of the element forming wafer; and
A step of separating the elements formed on the element forming wafer into individual elements while being supported by the support wafer
Can be implemented in order or in a different order. Further, in addition to these steps, a step of forming a functional element may be incorporated at an arbitrary stage.
[0043]
In the practice of the method of the present invention, the element forming wafer and the support wafer can be made of semiconductor materials and the like, respectively, as described above. Also, the bonding film having the groove pattern is advantageously formed from a resist material, as described above, and pattern exposure and development are performed on the film of the resist material in accordance with the groove pattern of the bonding layer. It is advantageous to form a resist film having a groove pattern. The details of the method for forming the bonding layer are as described above.
[0044]
According to the method of the present invention, the separated support wafer can be reused after separating the individual elements from the element forming wafer in the last step. That is, the used support wafer can be cleaned and then reused to form a new wafer structure. The ability to reuse the support wafer is very important in terms of environmental protection and reduction of manufacturing costs.
[0045]
FIG. 4 is a view for explaining a preferred embodiment of the device manufacturing method according to the present invention. The manufacturing of the device forming wafer structure of FIG. 3 and the device manufacturing method using the same are described in order. .
[0046]
First, although not shown, an element having a thickness corresponding to one of a thickness and a width of an element substrate which can form a plurality of elements and can be cut into individual elements in a later step A forming wafer is prepared. Next, functional elements required for forming elements are formed on the substrate element surface of the wafer. The functional elements to be built here may be all functional elements necessary for each element, or may be some functional elements. In the latter case, the remaining functional elements can be built on the element surface at a later stage or at any stage after the elements are individually separated.
[0047]
Next, a support wafer having substantially the same planar shape as the element formation wafer is manufactured.
[0048]
After the fabrication of the element formation wafer and the support wafer is completed, a resin material for forming a bonding layer is uniformly applied to a predetermined thickness on one of the back surface of the element formation wafer and the surface of the support wafer. Then, a film is formed. For example, a method of spin-coating a resist material can be advantageously used. In FIG. 4A, a resist material (a precursor of a bonding layer) 71 is formed by spin-coating a resist material on the surface of a support wafer 70. Is formed.
[0049]
Next, the resist film 71 on the support wafer 70 is selectively irradiated with light having sensitivity in a predetermined pattern, and further developed. As shown in FIG. 4B, a bonding layer 71 made of a resist film having a groove pattern 72 is formed. The resist film 71 having the groove pattern 72 is preferably heated or reflowed immediately or after performing the entire surface exposure at a predetermined high temperature.
[0050]
After the groove pattern is formed in the bonding layer, as shown in FIG. 4C, the back surface of the device forming wafer 60 and the surface of the support wafer 70 are bonded via the bonding layer 71, and both are hardened by the resist material. To adhere. The device-forming wafer structure of the present invention shown in the drawing and described above with reference to FIG. 3 is obtained.
[0051]
Next, although not shown, functional elements are formed on the surface of the element forming wafer 60 according to a predetermined design design to form a plurality of elements. This step may be omitted if the functional element is formed at another stage.
[0052]
Subsequently, as shown in FIG. 4D, the devices formed on the device forming wafer 60 are cut into individual devices 24 while the device forming wafer 60 is supported by the support wafer 70. This separation step can be performed using, for example, the dicer 62 in the same manner as in the conventional method. Accordingly, as shown in FIG. 4E, a large number of elements 24 (in the case of a magnetic recording head, a head 24 having a head element surface a and a head floating surface b) can be manufactured accurately and collectively. The device yield is also good. Note that the support wafer 70 is recycled.
[0053]
In addition to the above-described element forming wafer structure and element manufacturing method, the present invention relates to a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information. So,
Including a substrate and a functional element formed on and / or inside the substrate; and
A magnetic recording head characterized by being cut out from the element forming wafer structure of the present invention, and
A magnetic disk drive comprising a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
The magnetic recording head includes a substrate and a functional element formed on and / or inside the substrate, and
A magnetic disk drive cut out from a device-forming wafer structure according to the present invention.
It is in.
[0054]
The magnetic recording head and the magnetic disk device of the present invention are the same as the conventional ones, except that the head is cut out from the element forming wafer structure of the present invention by a multi-piece method. Therefore, a detailed description of the individual components will be omitted here.
[0055]
7 to 11 are examples showing preferred embodiments of the magnetic recording head and the magnetic disk drive of the present invention.
[0056]
FIG. 7 is a plan view showing the entire internal structure of the magnetic disk drive. In a state where the magnetic disk D is rotating at a high speed, the magnetic head 1 moves in the radial direction to perform a seek operation to record / reproduce information. Reproduction is performed. In the figure, reference numeral 2 is a spindle, 3 is a suspension, 4 is a drive arm, and 5 is a voice coil motor. When the magnetic disk D is cut and enlarged at the position of the magnetic head 1, the result is as shown in FIG.
Referring to FIG. 8, in the thin-film magnetic disk D, reference numeral 11 denotes a substrate made of a non-magnetic material such as aluminum or glass, on which a NiP plating layer 12 is formed to increase mechanical strength. In this state, a Cr underlayer 13 for increasing the horizontal orientation of the Co alloy is formed by sputtering to a thickness of about 1000 °. Then, a magnetic material such as CoCrTa or CoNiCr is sputtered to a thickness of about 500 ° to form a thin-film magnetic film 14, and then carbon, DLC (diamond-like carbon) or the like is sputtered to a thickness of about 300 ° as a protective film 15. Finally, a fluorine-based lubricating layer 16 such as perfluoropolyether is applied to a thickness of about several tens of millimeters to complete the magnetic disk D.
[0057]
As shown in FIG.₁The head element 18 records / reproduces information on / from the magnetic disk D in a state where the magnetic head slider 1 is floated by a very small amount due to wind force. The slider 1 of the magnetic head is attached to a suspension (spring arm) 3 via a gimbal 20, and a seek operation is performed by a drive arm 4 of a carriage 22. As described above, due to the simplicity of the mechanism, the CSS (Contact Start and Stop) system in which the core slider slides without floating when the apparatus is started or stopped has been widely used.
[0058]
FIG. 9 shows an MR type magnetic head. In this magnetic head, the head element section 24 is formed by thin-film technology, and₂O₃Is covered with a protective film. The slider 1 has flying rails 25 and 26 on the left and right sides of the sliding surface, and inflow slopes 25 s and 26 s for taking in an air flow are formed on the opposite side of the head element portion 24.
[0059]
FIG. 10 is an enlarged view of a main part of the magnetic head shown in FIG. Here, FIG. 10A is a cut-away perspective view of the magnetic head, and FIG. 10B is a cross-sectional view along the line XX of FIG. The magnetic head 40 is a composite thin film magnetic head of an electromagnetic transducer head (recording head) and a magnetoresistive (MR) head (reproducing head). In the drawing, a magnetoresistive head (MR head) 41 is shown. , A rectangular magneto-resistive element (MR element) 43 formed on a non-magnetic substrate 42, a lead conductor layer 44 of the MR element 43, and upper and lower magnetic shield layers 45a and 45b.
[0060]
The lead conductor layer 44 is cut at a predetermined width in the longitudinal direction of the MR element 43 and connected to both ends of the MR layer of the MR element 43. The MR element 33 and the lead conductor layer 44 are electrically connected to the magnetic shield element layer 45b by the nonmagnetic insulating layer 36.
[0061]
On the other hand, an electromagnetic conversion type head (inductive head) for recording information on the magnetic disk D has an upper magnetic shield element 45a of the MR head 41 as a lower magnetic pole (first magnetic pole), and alumina (Al) on the upper surface in order.₂O₃), The interlayer insulating layer 49 made of a thermosetting resin, the thin-film coil conductor layer (Cu) 50, and the upper magnetic pole 51 are laminated through a recording gap, and the upper magnetic pole (second magnetic pole) 51 and the lower magnetic pole (upper magnetic shield) are stacked. Horizontal recording of information is performed by the recording gap 48 formed by the layer 45a. Further, a protective insulating layer 52 is formed on the upper magnetic pole 51. These are formed by sputtering or vacuum evaporation plating.
[0062]
In FIG. 10B, reference numeral 6 denotes a protective layer made of DLC, on which a fluorinated layer 17 is optionally formed as a lubricating protective layer by coating.
[0063]
Further, the magnetic head as shown can be manufactured by, for example, the method described above with reference to FIG. 1 and the method shown in FIG. Although FIG. 1 shows a method of forming a large number of head element portions in a matrix on a substrate, it is necessary to change the wafer processing step according to the present invention, for example, as shown in FIG. FIG. 11 shows a method of separating and finishing sliders one by one from one row of slider blocks.
[0064]
Referring again to FIG. 1, as shown, a large number of head element sections 24 are simultaneously formed in a matrix on a substrate 60 made of ferrite, AlTiC, or the like by a thin film technique, and finally formed at cutting lines 28 and 29. Separate them one by one from the positions shown to complete the thin-film magnetic head. In the manufacturing order, first, the core slider block 30 in which the head element portions 24 are arranged in one line is formed by cutting and separating at the position of the cutting line 28 in the horizontal direction.
[0065]
Next, after cutting out the core slider block, the surface is cleaned, and a DLC layer is formed by a CVD method in the same manner as in the case of the magnetic disk. Here, a SiC film may be formed by a CVD method as a base adhesion layer of the magnetic head before forming the protective film. Note that in the CVD apparatus, a chemical reaction is used without using a sputter target into which impurities are easily mixed, so that a substance which causes corrosion during film formation can be prevented from being mixed.
[0066]
After the core slider block 30 is formed as described above, by grinding one by one, the floating rails 25 and 26 are formed as shown in FIG. That is, grooves are formed between the left and right flying rails 25 and 26 and between adjacent sliders. The slider rail can be formed by ion milling. Next, in a state of being cut and separated one by one at the position of the cutting line 29 at the center of the groove, as shown in FIG. 11B, the wrapping tape is attached to a jig 33 at regular intervals and attached to a rubber platen 34. The edge of the periphery of the floating rails 25 and 26 is polished and chamfered. After the R chamfering, the slider 7 is peeled off from the jig 33 and fixed one by one to the gimbal 20 at the tip of the spring arm 3 as in the conventional case. The recording / reproducing of information is performed in a state of only floating (see FIG. 8).
[0067]
【Example】
Subsequently, the present invention will be described with reference to examples thereof. It goes without saying that the present invention is not limited by these examples.
Example 1
On a 0.75 mm thick AlTiC substrate (may be a Si substrate), a positive photosensitive resist having a novolak resin as a base resin, trade name “ZPP-1500” (manufactured by Nippon Zeon Co., Ltd.) is applied in a thickness of 4 μm. For 90 seconds. The obtained resist film was exposed to light in a predetermined lattice pattern using a mask, and further developed. The mask used here is for forming a lattice pattern having a side of 2 mm (arbitrarily adjustable within a range of 500 μm to 5 mm) on the entire surface of the resist film in a groove shape. The width of the groove formed in the resist film was 100 μm (arbitrarily adjustable in the range of 10 to 500 μm). Since the lattice-shaped grooves are present on the surface of the resist film, it is possible to prevent entrapment of gas, adhesion failure due to degassing from the resist, and lowering of flatness when the substrates are bonded at a later stage.
[0068]
Next, an AlTiC substrate (may be a Si substrate or a SiC substrate) having a thickness of 1.25 mm was accurately aligned and laminated on an AlTiC substrate having a thickness of 0.75 mm provided with a grooved resist film. The obtained laminate was placed on a hot plate, and 0.3 kg / cm²(0.1-5kg / cm²). The heating temperature was increased from room temperature to 250 ° C. at a rate of 10 ° C. per minute, and then cooled to room temperature. A wafer structure was obtained in which two AlTiC substrates were firmly adhered to each other via a grooved resist film.
[0069]
When the warpage of the wafer structure was measured on its surface, it was 0.65 μm / cm. In addition, in the case of this wafer structure, it was confirmed that there was no problem such as peeling of the wafer in the annealing process at 230 ° C. and the CMP process. Furthermore, the bonded wafers could be easily peeled off simply by inserting a wedge-shaped blade between the two wafers.
Example 2
The method described in Example 1 was repeated to manufacture a wafer structure. In this example, in order to manufacture a wafer structure having higher heat resistance, the resist material was replaced with a positive photosensitive resist, trade name “ZPP-1500”, and was replaced by the example disclosed in JP-A-11-130860. A chemically amplified resist containing a silicon-containing polymer having a weight-average molecular weight of 10,000 and a dispersity of 3.4 prepared as a base resin was used.
[0070]
In the case of this example, a wafer structure was obtained in which two AlTiC substrates were more firmly bonded via the grooved resist film. When the warpage of the wafer structure was measured on the surface, it was 0.65 μm / cm as in Example 1. Furthermore, in the case of this wafer structure, by setting the maximum temperature of the heating to 650 ° C., it was confirmed that there was no peeling or deformation even after annealing up to 600 ° C. Furthermore, the bonded wafers could be easily peeled off only by inserting a wedge-shaped blade between the two wafers.
[0071]
The present invention has been described with reference to the embodiments and examples. Finally, preferred embodiments of the present invention are summarized as follows, for further understanding of the present invention.
[0072]
(Supplementary Note 1) An element formation wafer structure used for forming a substrate and an element including a functional element formed on a surface and / or inside the substrate,
An element forming wafer having a thickness corresponding to one of the thickness and the width of the substrate, which can be formed into a plurality of the elements and can be cut into individual elements in a subsequent step,
A supporting wafer bonded to a back surface of the device forming wafer via a bonding layer, and
The bonding layer is formed of a cured product of a resin material entirely formed with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer, and has a groove pattern. A wafer structure for forming an element.
[0073]
(Supplementary Note 2) The device-forming wafer structure according to Supplementary Note 1, wherein the element forming wafer and the support wafer are made of the same or different semiconductor materials.
[0074]
(Supplementary Note 3) The device-forming wafer structure according to Supplementary Note 1 or 2, wherein a warpage amount measured on a surface of the device-forming wafer after bonding is 1 μm / cm or less.
[0075]
(Supplementary note 4) The wafer structure for element formation according to any one of Supplementary notes 1 to 3, wherein the element is a magnetic recording head.
[0076]
(Supplementary Note 5) A method for collectively manufacturing a substrate and a plurality of elements including a functional element formed on the surface and / or inside of the substrate, comprising the following steps:
A plurality of the elements are formed, and an element forming wafer that can be cut into individual elements in a subsequent step and has a thickness corresponding to one of the thickness and the width of the substrate is manufactured. Process,
Producing a support wafer having substantially the same planar shape as the element forming wafer,
A step of forming a bonding layer made of a resin material having a groove pattern on a whole surface with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer;
Laminating the back surface of the element forming wafer and the surface of the support wafer via the bonding layer, and bonding the two by curing the resin material;
Forming a plurality of the elements by forming the functional elements according to a predetermined design on a surface of the element forming wafer; and
A step of separating the elements formed on the element forming wafer into individual elements while being supported by the support wafer
A method for manufacturing an element, comprising:
[0077]
(Supplementary Note 6) The bonding layer is formed from a resist material, and a pattern of the resist material is subjected to pattern exposure and development in accordance with the groove pattern to form a resist film having a groove pattern. 3. The method for manufacturing an element according to 1.
[0078]
(Supplementary note 7) The element according to Supplementary note 6, wherein a resist material containing as a base resin one member selected from the group consisting of a novolak resin, a silicon-containing resin, and an epoxy resin is used as the resist material. Manufacturing method.
[0079]
(Supplementary Note 8) The resistive film having the groove-shaped pattern is entirely exposed, and then the device forming wafer and the support wafer are bonded by heating and reflowing further. A method for manufacturing an element.
[0080]
(Supplementary note 9) The method for manufacturing an element according to any one of Supplementary notes 5 to 8, further comprising a step of separating the support wafer from the element formation wafer and reusing the same.
[0081]
(Supplementary note 10) The method for manufacturing an element according to any one of Supplementary notes 5 to 9, wherein a magnetic recording head is manufactured as the element.
[0082]
(Supplementary Note 11) A magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
Including a substrate and a functional element formed on and / or inside the substrate; and
3. A magnetic recording head, which is cut out from the element forming wafer structure according to claim 1 or 2.
[0083]
(Supplementary Note 12) A magnetic disk drive including a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
The magnetic recording head includes a substrate and a functional element formed on and / or inside the substrate, and
3. A magnetic disk drive cut out from the element formation wafer structure according to claim 1 or 2.
[0084]
【The invention's effect】
As described above, according to the present invention, the length of the long side of the air bearing surface can be designed to be short in the manufacture of a magnetic recording head, and the back surface of the wafer is not required, and sludge generated by the polishing is eliminated. It is possible to provide a device-forming wafer structure in which the amount can be significantly reduced and the components can be reused.
[0085]
According to the present invention, a magnetic recording head and other elements can be advantageously manufactured using the wafer structure of the present invention. The obtained magnetic recording head and magnetic disk device are small in size, and have a high level of recording density and mounting density.
[0086]
In particular, according to the present invention, it is possible to supply a bonded-type wafer structure having good bonding strength, heat resistance and flatness, thereby eliminating the need for polishing the back surface of the wafer which is essential in the production of a conventional magnetic recording head. In addition, sludge generated by polishing can be eliminated or its amount can be reduced. Further, the support wafer used for the purpose of supporting the element forming wafer can be used repeatedly.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating cutting of a core slider block from a wafer in a conventional method.
FIG. 2 is a cross-sectional view for sequentially explaining the cutting of a head element portion from a core slider block in a conventional method.
FIG. 3 is a cross-sectional view showing one embodiment of a device-forming wafer structure according to the present invention.
FIG. 4 is a cross-sectional view for sequentially explaining the production of the device-forming wafer structure of FIG. 3 and a device production method using the same.
FIG. 5 is a plan view showing a preferred example of a groove-like pattern of a bonding layer incorporated in a wafer structure for element formation.
FIG. 6 is a plan view showing another preferred example of a groove-like pattern of a bonding layer incorporated in a wafer structure for element formation.
FIG. 7 is a plan view showing a preferred embodiment of a magnetic disk drive according to the present invention.
8 is a sectional view showing a positional relationship between a magnetic disk and a magnetic recording head in FIG. 7;
FIG. 9 is a perspective view showing a preferred embodiment of a magnetic recording head according to the present invention.
10 is a perspective view (A) of a main part of the magnetic recording head shown in FIG. 9 and a cross-sectional view (B) taken along line XX of FIG. 9;
FIG. 11 is a sectional view sequentially showing a method of mass-producing the magnetic recording head.
[Explanation of symbols]
24 head element section
a: Head element surface
b: Head floating surface
60: wafer for element formation
62 ... Dicing blade
70 ... Support wafer
71 ... bonding layer
72… Groove pattern

Claims (5)

An element formation wafer structure used for forming a substrate and an element including a functional element formed on a surface and / or inside of the substrate,
An element forming wafer having a thickness corresponding to one of the thickness and the width of the substrate, which can be formed into a plurality of the elements and can be cut into individual elements in a subsequent step,
A support wafer bonded to a back surface of the device formation wafer via a bonding layer, and the bonding layer is provided on one of the back surface of the device formation wafer and the surface of the support wafer. A wafer structure for element formation, comprising a cured pattern of a resin material formed entirely over a predetermined thickness and having a groove pattern. A method for collectively manufacturing a substrate and a plurality of devices including a functional device formed on a surface and / or inside the substrate, comprising the following steps:
A plurality of the elements are formed, and an element forming wafer that can be cut into individual elements in a subsequent step and has a thickness corresponding to one of the thickness and the width of the substrate is manufactured. Process,
Producing a support wafer having substantially the same planar shape as the element forming wafer,
A step of forming a bonding layer made of a resin material having a groove pattern on a whole surface with a predetermined thickness on one of the back surface of the element forming wafer and the surface of the support wafer;
Laminating the back surface of the element forming wafer and the surface of the support wafer via the bonding layer, and bonding the two by curing the resin material;
Forming the functional elements on the surface of the element forming wafer in accordance with a predetermined design design to form a plurality of the elements, and the element forming wafer while being supported by the support wafer A step of separating the element formed in the step (a) into individual elements. 3. The resist film according to claim 2, wherein the bonding layer is formed from a resist material, and a film of the resist material is subjected to pattern exposure and development in accordance with the groove pattern to form a resist film having a groove pattern. Device manufacturing method. A magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
A magnetic recording head comprising a substrate and a functional element formed on the surface and / or inside of the substrate, wherein the magnetic recording head is cut from the wafer structure for element formation according to claim 1. A magnetic disk device comprising a magnetic recording head including a recording head for recording information on a magnetic recording medium and a reproducing head for reproducing information,
The magnetic recording head includes a substrate and a functional element formed on the surface and / or inside of the substrate, and is cut out from the element forming wafer structure according to claim 1. Magnetic disk drive.

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