JPH10109242A - Chuck table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To repair a damaged chuck part at low cost by removably placing the chuck part on a table body. SOLUTION: A table body 34 has a plurality of ring-shaped housing recesses 37 on a concentric path and chuck parts 35 are removably placed in the housing recesses 37. The chuck part 35 is made of porous ceramics of porous metal material. When one or a few chuck parts 35 are clogged or have some defects, only such chuck parts 35 are removed from the table body 34 and replaced by new chuck parts 35 to repair a chuck table 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chuck table for fixing a workpiece, in particular, a substrate body of a substrate for a magnetic recording medium in a grinding apparatus or a polishing apparatus.

[0002]

2. Description of the Related Art A recording medium substrate typified by a magnetic disk substrate has a lapping process for roughly polishing the surface of a substrate body, a chamfering process for grinding and chamfering the inner and outer peripheral end surfaces, and a polishing process for finish polishing the surface. It has been manufactured through.

In the above-described lapping and polishing steps, the substrate body is fixed to a chuck table provided in a grinding device or a polishing device, and lapping or polishing of the substrate body surface is performed.

Some of the above chuck tables are provided with various chuck systems such as a wax system, an electromagnetic system, and a vacuum system. Among them, the porous type vacuum chuck table 110 is, as shown in FIG.
A chuck 113 made of a porous metal material or inorganic material is fixed to the accommodation recess 112 formed in
Negative pressure is applied to the myriad of pores of the chuck portion 113 to suck (vacuum chuck) one or more substrate bodies 1A on the chuck portion 113.

[0005]

However, in the above-mentioned conventional vacuum chuck table 110, the chuck portion 11 is not provided.
When a part of the chuck table 110 is damaged, the chuck portion 113 is fixed to the table main body 111.
Must be replaced. For this reason, it is costly to deal with damage to the chuck portion and the like.

SUMMARY OF THE INVENTION The object of the present invention is to provide a chuck table which can cope with the occurrence of troubles such as damage to the chuck portion at a low cost. .

[0007]

According to a first aspect of the present invention, in a chuck table for fixing a workpiece, a plurality of chuck portions are arranged on a table body, and the chuck portions are made of a metal material or a porous structure. Made of an inorganic material, the work piece can be adsorbed by negative pressure,
The chuck portion is detachably mounted on the table body.

According to a second aspect of the present invention, in the first aspect of the present invention, the chuck portion is removably housed and installed in a recess formed in the table body.

The invention described in claim 3 is the first or second invention.
In the invention described in (1), the chuck portion is detachably mounted on the table main body in a state protruding from the surface of the table main body.

[0010] According to a fourth aspect of the present invention, in the first aspect of the present invention, the chuck portion includes:
It is detachably mounted on the table body by mechanical coupling, coupling by magnetic field, coupling by freezing, or coupling by an adhesive that can be melted at a predetermined temperature.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the table body and the chuck portion are made of ceramics.

According to a sixth aspect of the present invention, in the first aspect of the present invention, the surfaces of the table body and the chuck portion are coated with a resin layer or a carbon layer. .

The invention according to claim 1 or 4 has the following operation. Since the chuck section is detachably mounted on the table body, even if a trouble such as clogging or defect occurs in one or several of the plurality of chuck sections, for example, Only the part can be detached from the table body and replaced with a new chuck part to repair the chuck table. Therefore, as compared with a case where the entire chuck table is replaced, troubles such as damage to the chuck portion can be dealt with at low cost, and as a result, one chuck table can be used for a long time. .

The second aspect of the present invention has the following operation. Since the chuck portion is housed and installed in the concave portion of the table main body, the positioning accuracy of the chuck portion during assembly of the chuck table can be improved,
High rigidity can be ensured even for a reaction force acting on the chuck portion from the workpiece during grinding.

The third aspect of the invention has the following operation. Since the chuck portion is installed in a state protruding from the surface of the table main body, it is possible to easily perform the reference setting operation of the suction surface of the chuck portion.

The invention described in claim 5 has the following operation. Since the table body and the chuck portion are made of ceramics, the ceramics have higher rigidity than metal, so that the workability of the table body and the chuck portion can be improved.

The invention according to claim 6 has the following operation. Since the surfaces of the table body and the chuck portion are covered with a resin layer or a carbon layer, the resin layer or the carbon layer can prevent the table body and the chuck portion from being damaged from the outside, and can also prevent the table body and the chuck portion from being damaged. Adhesion of dust to the chuck can be prevented.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a process diagram showing a manufacturing process of a GC substrate from a lapping process after firing to completion of a substrate main body. FIG. 2 is a front view showing a chuck table provided in the grinding device of FIG. FIG. 3 is a sectional view of FIG.
It is sectional drawing which follows the I-III line. FIG. 4 is a back view of the chuck table of FIG. FIG. 5 is a cross-sectional view showing an attached state of the chuck unit of FIG. FIG. 6 is a schematic diagram showing a fan-shaped processing mark. FIG. 7 is a cross-sectional view illustrating a shoulder generating line shape of the grindstone. FIG. 8 is a configuration diagram showing an arrangement structure of electrodes and the like when performing electrolytic in-process dressing in a grinding device.

In this embodiment, the grinding wheel 31 of the grinding device 30 is used.
Is performed by the following (1) and (2). (1) The finish grinding using the grindstone 31 of the grinding device 30 may be brittle mode processing, but is preferably performed by ductile mode processing.

In the present specification, "ductile mode processing" refers to plastic fluid removal processing that does not involve the generation of cracks even in a brittle material, that is, grinding processing characterized by no damage to the material instead of brittle fracture (crushing). Means Such a processing technique is achieved by always keeping the depth of cut of the individual abrasive grains in the material below the ductile-brittle transition point. Means for achieving this is not particularly limited, and a generally known method can be used. For example, most of the materials used for magnetic disk substrates containing carbon, which is a brittle material, have a ductile-brittle transition point (dc) of 2 to 100 n.
m, the set depth of cut of the grinding wheel is 0.05-20 μm,
Preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm
It is good. Here, the set depth of cut of the grindstone is preferably 0.05 μm or more from the viewpoint of device positioning accuracy, and 20 μm from the viewpoint of suppressing the grinding load and the occurrence of microcracks.
It is preferable to set the following.

[0021] Furthermore, the shoulder of the outer periphery of the wheel (fixed abrasive) is provided with an R in accordance with the set cutting depth of the grindstone, so that even if the set cutting depth of the grindstone is large, the ductile work surface free of micro cracks. Is more preferable (FIG. 7). The shape of R and the like may be set so that the cutting depth of each abrasive grain is smaller than dc of the material to be ground. For example, in the formula shown below,

(Equation 1) (Here, d _N is a cutting depth per one rotation of the substrate to be processed, and is represented by the following equation.)

[0022]

(Equation 2) Also, f is the amount of lateral movement of the wheel per rotation of the substrate to be processed, Δ is the set depth of cut, R is the radius of curvature of the shoulder on the outer periphery of the wheel, d _g is the depth of cut of individual abrasive grains, and a is the grinding depth. Grain spacing, V
_W is the peripheral speed of the substrate, _Vg is the peripheral speed of the wheel, and D
Indicates the wheel diameter. ) D _g <may be set so that the dc.

By grinding in this manner, the substrate body 1A
Thus, a surface with reduced generation of microcracks can be obtained. Of course, since fan-shaped processing marks are provided on the surface of the substrate body 1A, smoothing by grinding is favorably achieved, which is economically advantageous.

In the present specification, "fan-shaped" of the fan-shaped machining mark
Is a substantially concentric shape as schematically shown in FIG. The center of the concentric circle may be on the substrate main body 1A or may be outside the substrate main body 1A. Preferably, the relationship between the radius r ₁ of the substrate body 1A and the radius r _{2 of the} processing trace satisfies r ₂ ≧ r ₁ , more preferably
From the viewpoint of the mounting workability of the substrate body 1A to be processed and the processing accuracy of the apparatus, the relationship 100r ₁ ≧ r ₂ ≧ 2r ₁ is satisfied.

As described above, the set depth of cut of the grindstone at the time of the above-mentioned ductile mode machining is set at 0.1 from the viewpoint of device positioning accuracy and the viewpoint of suppressing the grinding load and the occurrence of microcracks.
It is preferably from 05 to 20 μm. In order to achieve ductile mode processing at a set cutting depth of the grinding wheel of 0.05 to 20 μm, the grinding device 30, the grinding wheel 31, and the like must satisfy the following conditions.

1) Setting and manufacturing a grinding wheel spindle with extremely high dynamic rigidity. Radial and axial motion error is less than 100nm.

2) Design and manufacture of a workpiece support and motion system having extremely high dynamic rigidity. As a rule of thumb, the loop stiffness between the machine tool and the workpiece should be 150 N / μm (static stiffness) or more.

3) Dressing of an abrasive binder to ensure high precision truing of the grindstone 31 and an appropriate porosity.
Further, the distribution of the cutting edge height of the individual abrasive grains on the grinding stone 31 is dc.
It is desirable that:

Therefore, the grinding device 30 used in the present invention
Is not particularly limited as long as the above conditions are satisfied. Specifically, for example, an ultra-precision surface grinding device (HPG-2A) manufactured by Nissin Machinery Co., Ltd. is exemplified. Ultra-precision surface grinding machine (HPG-2A)
It has been developed for the purpose of ductile mode processing of brittle materials and has the following characteristics.

1) Radial and axial movement accuracy is 100 nm or less. 2) Loop rigidity between the machine tool and the workpiece is 170 N / μm.
(Static rigidity) 3) Truing accuracy is 100nm

Therefore, this ultra-precision surface grinding device (HPG
-2A) satisfies all of the above device conditions.

In order to form the above-mentioned fan-shaped machining marks, for example, the substrate body 1A to be machined is placed on a chuck table 33 (described later) mounted on a work spindle 32 of a grinding device 30 shown in FIG. The chuck table 33 is rotated eccentrically so as not to include the rotation center of the work spindle 32, that is, so as to satisfy the relationship of r ₂ ≧ r ₁ , and a minute cut is given to the grindstone 31 (straight wheel). What is necessary is just to move the grindstone 31 relatively sideways along the chuck table 33 in the arrow X direction. In addition, whetstone 31
A metal bond wheel (having abrasive grains such as diamond abrasive grains fixed on the outer circumference of a straight wheel with a metal binder) can be preferably used.

(2) As shown in FIG. 8, in the finish grinding using the grindstone 31 of the grinding device 30, the electric field of the anode of the power supply 20 is applied to the grindstone 31 and the cathode of the power supply 20 is integrated with the coolant supply device 21. Connected to the electrode 22 that has been used.
Here, the electrode 22 is installed so as to cover a part of the outer periphery of the grindstone 31. In addition, the coolant supply device 21 includes the electrode 2
A coolant containing an electrolyte is supplied between the grinding wheel 2 and the grinding wheel 31. Grinding while rotating both the substrate body 1A and the grindstone 31 realizes electrolytic in-process dressing (ELID) by dissolving the metal pond of the grindstone 31, and grinds the substrate body 1A in ductile mode.

As described above, Ra (surface roughness) is 2
~ 100 angstroms, Rp (surface height) /
A surface-processed substrate having Ra of 2 to 10 is obtained. Where Ra
Is more preferably 2 to 50 angstroms, and particularly preferably 2 to 30 angstroms. From the viewpoint of grinding productivity, 2 angstrom or more is preferable.For example, when used for a magnetic disk, from the viewpoint of head flying characteristics.
100 angstrom or less is preferred. Also, Rp / R
a is more preferably 2 to 8, particularly preferably 2 to 4. Here, the number is preferably 2 or more from the viewpoint of reducing the management burden of the truing (shape correcting) process of the wheel, and is preferably 10 or less from the viewpoint of the surface sliding durability. Further, the surface-processed substrate of the present invention preferably has a flatness of 10 μm or less from the viewpoint of the floating running stability of the magnetic head. A more preferred value is 6 μm or less.

Here, in this specification, Ra is a value obtained by measuring using a stylus type surface roughness meter (model P2, manufactured by Tencor Corporation) under the following conditions. Measurement conditions Stylus tip radius: 0.6 μm (needle curvature radius) Stylus pressing force: 7 mg Measuring length: 250 μm × 8 points Trace speed: 2, 5 μm / sec Cutoff: 1.25 μm (Low-bass filter) , Manufactured by ZYGO (Model: Mark-4)
Was measured by In this specification, Ra, Rp, and flatness were measured by scanning a stylus in a direction orthogonal to the shape of the processing mark (a direction in which roughness or the like becomes maximum).

The work spindle 32 of the grinding apparatus 30 shown in FIG. 1 is equipped with a chuck table 33.
A is sucked (vacuum chuck).

This chuck table 33 is shown in FIGS.
As shown in FIG. 7, a plurality of ring-shaped chuck portions 35 are arranged on a donut-shaped table body 34, and one substrate body 1A is attracted to each chuck portion 35.

A plurality of ring-shaped receiving recesses 37 are formed on the table body 34 on the locus of concentric circles 36, and the chuck portions 35 are detachably installed in these receiving recesses 37, respectively. In this installation state, the chuck 35
The suction surface 42 (described later) is flush with the surface 43 of the table body 34 as shown in FIGS. 3 and 5A, or the surface 43 of the table body 34 as shown in FIG. 5B. Is set to protrude from

The chuck 35 can be detachably mounted in the housing recess 37 by mechanical coupling, magnetic field coupling, freezing coupling, bonding with an adhesive that can be melted at a predetermined temperature, or the like.

Of these, the mechanical connection is performed by the chuck 35
Is connected to the table body 34 by bolts 44 (FIG. 5 (A)), or a taper 46 is formed on the convex portion 45 of the table body 34 and the inner peripheral surface of the chuck portion 35, and these are wedge-connected.

The coupling by the magnetic field is performed by the table body 3.
A magnetic material is fixed to one of the accommodation recess 37 and the chuck 35 of FIG. 4 and a magnet is fixed to the other, and the chuck 35 is coupled into the accommodation recess 37 by the action of these magnetic forces. As the magnet, an electromagnet is preferable because it is easily detachable.

Further, the connection by freezing is performed by the table body 3.
Water is interposed in the gap between the accommodation recess 37 of No. 4 and the chuck portion 35, and this moisture is frozen to couple the chuck portion 35 to the accommodation recess 37 of the table body 34.

Further, the bonding by the adhesive is performed by filling a gap between the accommodating concave portion 37 of the table body 34 and the chuck portion 35 with an adhesive that melts at a predetermined temperature of a resin or metal paste, and the temperature is lowered to the predetermined temperature or lower. It holds and couples the chuck portion 35.

The table body 34 is made of alumina (Al ₂ O).
It is composed of an inorganic material represented by ceramics such as ₃ ) or a metal material such as hardened steel.

The chuck portion 35 is made of a ceramic having a porous structure, for example, porous ceramics (Al ₂ O ₃ : 92.5% / SiO ₂ , TiO ₂ : 7) manufactured by Kyocera Corporation.
%) And Kyocera Corporation bead ceramics (Al ₂ O ₃ :
99.5%) or a metal material having a porous structure, such as “Pocerax II (registered trademark)” manufactured by Shinto Kogyo. The average pore diameter of the innumerable pores in the chuck portion 35 having such a porous structure is at least the adsorption surface 42.
(Described below), it is set to 300 μm or less.

The countless pores (not shown) of each chuck portion 35 are formed in a first ring groove 38, a communication groove 39, and a second ring groove 40 formed in the table body 34 and communicated with each other.
Is connected to the vacuum pipe 41 through the
Is connected to a vacuum source (not shown). Therefore, by the operation of the vacuum source, a negative pressure acts on the pores of each chuck 35 via the vacuum pipe 41, the second ring groove 40, the communication groove 39, and the first ring groove 38, and each chuck 35 has a suction surface. On 42
One substrate body 1A can be sucked (vacuum chucked).

Further, the outer diameter of each chuck portion 35 is configured to be smaller than the outer diameter of the substrate body 1A as a workpiece, and the entire suction surface 42 of each chuck portion 35 is covered by the substrate body 1A. . The surfaces of the table body 34 and the chuck 35 may be covered with a resin layer or a carbon layer.

According to the above embodiment, the following (1) to (11)
Has the effect of (1) Since the chuck portion 35 of the chuck table 33 is made of a porous material, when the substrate body 1A is sucked (vacuum chucked) by the negative pressure and ground or polished by the chuck portion 35, the chuck portion 35 Since the pore diameter of the 35 pores is minute, defects such as dimples (dents) and minute projections do not occur on the ground / polished surface of the substrate main body 1A, and the quality of the ground / polished surface of the substrate main body 1A is high. Can be.

(2) Since the outer diameter of the chuck portion 35 is smaller than the outer diameter of the substrate body 1A, the entire suction surface 42 of the chuck portion 35 is covered by the substrate body 1A. For this reason, at the time of suction (vacuum chuck) of the substrate body 1A by the chuck portion 35, contaminants such as grinding dust do not enter the chuck portion 35 via the suction surface 42,
Since the clogging of the chuck portion 35 can be prevented, the life of the chuck portion 35 can be extended.

(3) Further, the chuck portion 35 is mounted on the substrate body 1A.
Is sucked by a negative pressure (vacuum chuck). Therefore, if the negative pressure state is released, the substrate body 1A can be immediately removed from the chuck portion 35. For this reason, the substrate body 1A can be easily replaced without any trouble in attaching and detaching the substrate body 1A, and productivity can be improved.

(4) Further, a plurality of chuck portions 35 are arranged on the table body 34, and the substrate body 1A is mounted on each chuck portion 35.
Are adsorbed (vacuum chuck), the number of processed substrates 1A per batch increases, and the productivity is enhanced.

(5) Since the table body 34 and the chuck portion 35 are made of ceramics such as alumina (Al ₂ O ₃ ), since the ceramics have higher rigidity than metal, The workability of the chuck 35 can be improved.

(6) Further, since the average hole diameter of the suction surface 42 of the chuck portion 35 is set to 300 μm or less, even when the surface of the substrate body 1A having a small thickness is ground or polished, the substrate body can be used. The generation of defects such as dimples on the 1A ground / polished surface can be prevented, and the quality of the processed surface can be improved.

(7) Further, since the chuck portion 35 is disposed on the concentric trajectory of the table body 34, the radius r ₂ of the processing mark on the grinding / polishing surface of the substrate body 1A and the radius r _{1 of the} substrate body 1A And r ₂ ≧ r _1, and the processing marks can be fan-shaped marks.

(8) When the surfaces of the table body 34 and the chuck portion 35 are covered with a resin layer or a carbon layer, the outer surface of the table body 34 or the chuck portion 35 is covered with these resin layers or carbon layers. In addition to preventing damage to the table body 34 and the chuck portion 35, dust can be prevented.

(9) Since the chuck portion 35 of the chuck table 33 is detachably mounted on the table body 34, for example, one or several chuck portions 35 of the plurality of chuck portions 35 may be clogged. Even if a trouble such as a defect occurs, only the chuck portion 35 in which the trouble has occurred is detached from the table body 34 and a new chuck portion 3 is removed.
5, the chuck table 33 can be repaired. Therefore, as compared with the case where the entire chuck table 33 is replaced, troubles such as damage to the chuck portion 33 can be dealt with at low cost, and as a result, one chuck table 33 can be used for a long time. Can be used.

(10) Further, since the chuck 35 is housed and installed in the housing recess 37 of the table body 34, the positioning accuracy of the chuck 35 at the time of assembling the chuck table 33 can be improved. High rigidity can be ensured even for a reaction force acting on the chuck portion 35 from the substrate body 1A during grinding.

(11) When the chuck portion 35 is installed so as to protrude from the surface 43 of the table body 34 (FIG. 5B), the reference setting operation of the suction surface 42 of the chuck portion 35 is performed. Can be easily implemented.

[0059]

EXAMPLES Examples of the present invention will be described together with comparative examples. However,
The present invention is not limited to the following examples. (Processing of the substrate body) Ra350 angstrom, density 1.
A glassy carbon substrate (GC substrate) with 5g / cm ³ , diameter 1.89 inch, thickness about 1400μm, Vickers hardness 650,
Using a 9B 5L double-side polishing machine manufactured by EED FAM, and using GC (green silicon carbide abrasive) # 800 which is one of the crushed silicon carbide abrasive grains, a lapping process by a free abrasive method with a concentration of 4% by weight is performed. Done. The platen used was a cast iron platen. The polishing margin was 200 μm per side. Ra of the obtained carbon substrate was 0.6 μm. Thereafter, the inner and outer diameters were trimmed to predetermined dimensions and chamfering (45 °) (chamfering) was performed using a chamfering machine SG-T manufactured by Shiba Giken. Furthermore, using the double-side polishing machine,
Lapping was performed by a free abrasive method with a concentration of 20% by weight using GC # 4000 abrasives. This lap polishing was performed using a cast iron platen, and the grinding allowance was 70 μm per side. Ra of the obtained carbon substrate was 0.1 μm. Thereafter, chamfering was performed using the chamfering machine.

(Finishing Processing of Substrate Body) Both surfaces of the rough-processed carbon substrate are finish-ground by ductile mode processing.
A mirror-finished substrate was obtained. The main processing conditions are as follows.

Grinding device: Ultra-precision horizontal surface grinding device (HPG-2A manufactured by Nisshin Kikai Seisakusho Co., Ltd.) Work table diameter: 200 mm Work table rotation speed: 530 rpm Grinding wheel peripheral speed: 1260 m / min Grinding wheel feed speed: 30 mm / min Whetstone: # 8000 diamond whetstone (Shinto Blader Co., Ltd.)
SD8000 N100 FX3) Coolant: 2% aqueous solution of ELID No.35 manufactured by Yushiro Chemical ELID power supply: Shinto Breta Co., Ltd., pulse power supply ED
P-10A Initial truing: # 200 diamond (average particle size about 75
μm) (manufactured by Oriental Diamond Tool Laboratory: SD)
200Q75M) Initial dressing: 3A x 15 minutes Pulse (square wave) cycle: 4 microseconds

The shoulder of the grinding wheel of # 8000 diamond has a bus shape as shown in FIG. 8 (A) or (B) by precision truing, and the cutting depth of each abrasive grain is determined by the ductility-brittleness of the carbon substrate. It was set to be below the transition point (about 50 nm). The measurement of the arc shape (bus shape) is performed by an electric micrometer (manufactured by Tokyo Seimitsu Co., Ltd .: Minicom EM).
5P) and E-DT-LJ-M30 (measuring force of the detector is 7 gf).

The obtained surface-processed substrate was polished by a known method using free abrasive grains to obtain a mirror-finished substrate. The main polishing conditions are as follows. still,
The polishing liquid was supplied in a slurry form by adding predetermined amounts of abrasive grains and a polishing aid to water.

Polishing machine: 9B5P double-sided polishing machine manufactured by Speed Farm Abrasives: γ-Al ₂ O ₃ , particle size 0.05 μm, 0.15 wt% Polishing aid: aluminum lactate (1% by weight in polishing liquid), poly hydroxy Star sulfone sodium 1 wt% pressing pressure: 150 gf / cm ² polishing time: 30 minutes under plate rotation: 30 rpm polishing solution flow rate: 40 cc / min allowance: 6 [mu] m carrier: epoxy glass material pad: hard urethane pad (Rodel Nitta Ltd. C14
A)

Twelve substrates 1A are simultaneously fixed by a vacuum chuck using a chuck portion 35. The specifications of the chuck portion 35 are as follows in each of the first to fifth embodiments.
The difference is as shown in Table 1 (described later) and as follows.

(Example 1) Chuck portion: Porous ceramic (Al ₂ O ₃ : 92.5% / SiO ₂ , TiO ₂ : 7%) manufactured by Kyocera Corporation # 220 Average pore diameter: 20 μm Table body: Alumina chuck portion and table Connection with main body: wedge connection

(Example 2) Chuck part: Bead ceramic (Al ₂ O ₃ : 99.5%) manufactured by Kyocera Co., Ltd. Bead diameter of surface layer part: 0.4 μm Bead diameter of lower layer part: 1.0 μm Average pore diameter: 40 μm Table body: alumina Joint between chuck part and table body: Bolt connection

(Example 3) Chuck part: Porcelax II (registered trademark) manufactured by Shinto Kogyo Co., Ltd. Average pore diameter: 7 μm Table body: hardened steel Joining of chuck part and table body: joining by freezing

The chuck table in the comparative example of Table 1 is a wax type chuck table in Comparative Example 1.
Comparative Examples 2, 3 and 4 are multi-hole type vacuum chuck tables.

In the grinding by the above-mentioned grinding apparatus, one pass (forward direction) was performed with the set cutting depth of the grinding wheel being 4 μm.
This was performed by moving one pass (backward direction) at 2 μm on both surfaces of the substrate body 1A. Here, the reference directions of the forward direction and the backward direction are X in FIG.
Direction, which is achieved by moving the grindstone 31 in the X direction relative to the chuck table 33. still,
The evaluation of the table and the microprojections was performed by irradiating parallel light using a shadow graph manufactured by Mizojiri Optical Industrial Co., Ltd., and by counting reflected light having a diameter of 300 μm or more.

As shown in Table 1, when the chuck table 33 of each of Examples 1 to 5 was used, Comparative Example 2 was used.
As compared with Nos. To 4, there was no defect such as dimples or minute protrusions on the ground surface of the substrate body 1A, and a very high-quality surface-processed substrate was obtained.

In the chuck table 33 in each of the first to fifth embodiments, the substrate 1 is
Since A is attached and detached, the exchange work time for attaching and detaching the substrate main body 1A to and from the chuck table 33 can be shortened as compared with Comparative Example 1, and the productivity of the substrate main body 1A can be improved.

Further, even if one or several chuck portions 35 of the chuck table 33 have a trouble such as clogging or a defect, the chuck portion 35 in which the trouble has occurred.
Can be replaced with a new chuck portion 35, so that the chuck table 33 can be repaired at low cost, and as a result, the chuck table 33 can be used for a long time.

[0074]

[Table 1]

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration of the present invention is not limited to this embodiment, and the design can be changed without departing from the scope of the present invention. The present invention is also included in the present invention. For example, the material of the substrate body to which the present invention is applied is not limited to carbon,
Al alloy, Ti or the like may be used, but in the case of carbon, since the Young's modulus is small and dimples are easily generated, the greatest effect can be obtained.

[0076]

As described above, according to the chuck table of the present invention, it is possible to cope with troubles such as damage to the chuck portion at low cost.

[Brief description of the drawings]

FIG. 1 is a process diagram showing a manufacturing process of a GC substrate from a lapping process after firing to completion of a substrate main body.

FIG. 2 is a front view showing a chuck table provided in the grinding device of FIG. 1;

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a rear view of the chuck table of FIG. 2;

FIG. 5 is a cross-sectional view showing an attached state of the chuck unit of FIG. 2;

FIG. 6 is a schematic diagram showing fan-shaped processing marks.

FIG. 7 is a cross-sectional view illustrating a shoulder generating line shape of a grindstone.

FIG. 8 is a configuration diagram showing an arrangement structure of electrodes and the like when performing electrolytic in-process dressing in a grinding device.

FIGS. 9A and 9B show a conventional polar style vacuum chuck table, wherein FIG. 9A is a plan view and FIG.
It is sectional drawing which follows the IX-IX line of (A).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 glassy carbon substrate (GC substrate) 1A substrate main body 30 grinding device 33 chuck table 34 table main body 35 chuck portion 36 concentric circle 37 receiving recess 42 suction surface 43 surface 44 bolt 45 convex portion 46 taper

Claims (6)

[Claims] In a chuck table for fixing a workpiece, a plurality of chuck portions are arranged on a table body, and the chuck portion is made of a porous metal material or an inorganic material. A chuck table characterized in that it can be attracted by a negative pressure and the chuck section is detachably mounted on the table body. 2. The chuck table according to claim 1, wherein the chuck section is removably housed and installed in a recess formed in the table body. 3. The chuck table according to claim 1, wherein the chuck portion is detachably mounted on the table main body in a state protruding from a surface of the table main body. 4. The table according to claim 1, wherein the chuck portion is detachably mounted on the table body by mechanical coupling, coupling by magnetic field, coupling by freezing, or coupling by an adhesive meltable at a predetermined temperature. A chuck table according to any one of the above. 5. The chuck table according to claim 1, wherein the table body and the chuck portion are made of ceramics. 6. The chuck table according to claim 1, wherein the surfaces of the table body and the chuck portion are covered with a resin layer or a carbon layer.