JP2000288884A - Electrolytic in-process dressing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly control electrolytic action on a grinding wheel surface in electrolytic in-process dressing as compared to before, and to evenly generate the electrolytic action. SOLUTION: In this device, a gauge attachment part 12 is nearly horizontally fixed in a lower part of a post 11, while the gauge attachment part 12 extends under an electrode mounting member 7. A rotary gauge 13 for adjusting a gap is attached to the gauge attachment part 12. The front end of a measuring shaft 13c abuts on the lower face of the electrode mounting member 7 from beneath to support the electrode mounting member 7. Accordingly, by rotationally operating a rotational operation part 13a of the rotary gauge 13, the electrode mounting member 7 and an electrode 8 supported by it move up and down along a guide part 11a of the post 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic in-process dressing apparatus, and more particularly to a technique suitable for processing a thin quartz wafer for forming a quartz oscillator.

[0002]

2. Description of the Related Art Heretofore, a grinding method called electrolytic in-process dressing has been proposed. For details of the principle of this processing method, see RIKEN Symposium “Latest Trend of Mirror Grinding”
(Held on March 5, 2003).
No. 8266 discloses this.

[0003] As described in the above publication, in electrolytic in-process dressing, a conductive grindstone having abrasive grains embedded in a conductive base material is used, and the grindstone is brought into contact with a workpiece. In parallel with the grinding process, an electrolytic solution is brought into contact with the grindstone, and by applying an electric field, the conductive base material is eluted from the grindstone to expose the abrasive grains, so-called dressing (dressing). ) Is performed.

In general, a metal material called a metal bond is used as a conductive base material, and a passivation film may be formed on the surface of the conductive base material while the conductive base material is eluted by an electrolytic action. is there. Since this passivation film is insulative, the formation of the passivation film gradually suppresses the electrolytic action and further reduces the elution of the conductive substrate. Then, as the grinding process proceeds, the abrasive grains are worn, and the passivation film formed on the surface of the conductive substrate is eventually destroyed by the grinding. When the passivation film is destroyed, the electrolytic action is promoted again, the elution amount of the conductive base material increases, and the abrasive grains protrude from the surface of the grindstone. In the electrolytic in-process dressing process, in many cases, the above-mentioned phenomenon occurs repeatedly.Therefore, the grinding process can be performed while the grindstone is being dressed at all times. The processing speed can be improved even when using a suitable abrasive, and the processed surface can be kept good.

[0005]

However, in the above-mentioned electrolytic in-process dressing, if the strength of the electrolytic action of the grindstone is not appropriately set, the electrolytic action is excessively advanced and abrasive grains are likely to fall off. However, there is a problem that the wear of the grindstone becomes severe, and conversely, a sufficient electrolytic action is not obtained and the processing speed is reduced.

Also, an electric field (voltage) applied to the surface of the grinding wheel
If the surface becomes uneven, the electrolytic action that occurs on the surface of the grindstone also becomes nonuniform.Therefore, a portion where the electrolytic action locally progresses excessively on the grindstone surface or a portion where clogging occurs without the electrolytic action occurring May occur. For this reason, there is a problem that grinding quality is deteriorated due to irregularities being formed on the surface of the grindstone or variation in the projected state of the abrasive grains. In particular, when a passivation film is formed on the surface of the conductive substrate during electrolysis as described above, the above-described process of repeating the electrolysis is disrupted, and the electrolysis is concentrated only locally. In some cases, there is a problem that the sharpening effect of the grindstone cannot be sufficiently obtained.

[0007] An apparatus having a structure in which electrodes are opposed to the surface of a grindstone in order to make it possible to set an electrolytic action on the grindstone in electrolytic in-process dressing processing is described in, for example, JP-A-6-775. I have. In such a device, the electrodes are usually mounted on the device frame or the like by screwing. Here, in order to set the inter-electrode gap between the surface of the electrode and the surface of the grindstone, the electrode that has become movable by loosening the screwing structure corresponds to the desired inter-electrode gap between the grindstone. Insert a gauge plate with thickness, pull out the gauge plate while maintaining this state,
The height of the electrode is set by screwing. However, in this method, the gauge plate touches the electrode when the gauge plate is pulled out, so that the set thickness is shifted, or the electrode is removed from the gauge plate and fixed by screwing. There is a problem that the height of the electrode changes, and there is a problem that the gap between the electrodes cannot be accurately adjusted. Such poor adjustment of the inter-electrode gap causes the above-described poor dressing action, deteriorating the processing quality and lowering the processing speed.

Accordingly, the present invention is to solve the above-mentioned problems, and an object of the present invention is to make it possible to more reliably control the electrolytic action on the grindstone surface and to improve the electrolytic action in the electrolytic in-process dressing processing than before. It is an object of the present invention to provide a structure of a processing apparatus that can generate the data uniformly.

[0009]

In order to solve the above problems, an electrolytic in-process dressing apparatus according to the present invention comprises:
Work, a grindstone configured to be in contact with the work, and buried abrasive grains in a conductive substrate, an electrode facing the surface portion of the grindstone that is not in contact with the work at a predetermined interval, A power source for applying a voltage between the grinding wheel and the electrode, an electrolytic solution supply means for supplying an electrolyte between the grinding wheel and the electrode, and relatively moving the grinding wheel and the work, A drive unit configured to be able to process the work with the grindstone, and an electrolytic in-process dressing processing apparatus that processes the work while performing dressing by eluting the conductive base material from the grindstone by electrolytic action, A guide structure configured to move at least one of the whetstone and the electrode so as to be able to change a facing distance between the whetstone and the electrode, and at least one of the whetstone and the electrode. And settable positioning means the opposing distance to position one, is characterized by comprising a said opposing distance or measurable gap detecting means and the amount of change.

According to the present invention, at least one of the grindstone and the electrode is configured to be movable so that the facing distance can be changed by the guide structure, at least one of the grindstone and the electrode is positioned by the positioning means, and opposed by the spacing detecting means. Since the interval or the amount of change thereof can be measured, the opposing interval between the grindstone and the electrode can be set easily and with high precision by positioning while measuring by the interval detecting means. The processing quality can be improved, and the processing speed can be increased.

In the present invention, it is preferable that a plurality of the positioning means and the interval detecting means are provided at different opposing positions of the grinding wheel and the electrode.

According to the present invention, by providing a plurality of positioning means and interval detecting means at different opposing positions,
The facing interval can be set with higher accuracy, and in particular, the parallelism between the mutually facing grindstone surface and the electrode surface can be improved. Therefore, the electrolytic action on the surface of the grindstone can be generated more uniformly, so that the processing quality can be further improved. In this case, three or more sets of positioning means and spacing detecting means are arranged in a plane with respect to the opposing region between the grindstone and the electrode (arranged so that the positioning positions are not arranged in a straight line). Since the positioning can be carried out, the parallelism between the grinding wheel surface and the electrode surface can be further increased.

In each of the above inventions, the positioning means and the interval detecting means include a positioning part for directly or indirectly abutting on at least one of the grinding wheel and the electrode, and moving the positioning part by a rotating operation. It is preferable that the positioning section is constituted by a rotary gauge capable of measuring at least a position change amount of the positioning section.

According to the present invention, since both the positioning means and the interval detecting means are constituted by the rotary gauge, the structure of the apparatus is simplified, and the positioning accuracy is easily obtained since the positioning and measurement are performed by the rotating operation. be able to.

In each of the above inventions, a first positioning means having a first positioning portion for directly or indirectly abutting on at least one of the whetstone and the electrode for positioning,
A second positioning unit having a second positioning unit configured to be able to set a position independently with respect to the first positioning unit and directly or indirectly abutting on at least one of the whetstone and the electrode for positioning. The interval detecting means,
It is preferable that at least a position change amount of the second positioning section can be measured.

According to the present invention, the facing distance is provisionally set by directly or indirectly contacting the first positioning portion of the first positioning means with at least one of the grindstone and the electrode, and the distance detecting means detects the distance therebetween in the meantime. (2) Since the position of the positioning portion can be set, after the position of the second positioning portion has been set, the first positioning portion is moved from the contact position to release the positioning action, thereby setting the facing distance by the second positioning portion. can do. Therefore,
Since the measurement of the interval detecting means and the position setting of the second positioning portion can be performed irrespective of the positioning state of at least one of the grindstone and the electrode, the position setting can be easily performed.

In the present invention, a plurality of the second positioning means are provided at different opposing positions of the grinding wheel and the electrode,
It is preferable to include a plurality of the interval detecting means configured to be able to measure at least a position change amount of the second positioning portion provided in each of the plurality of second positioning means independently of each other.

According to the present invention, positioning can be performed at different opposing positions by the plurality of second positioning means, so that the opposing interval can be set more accurately. The parallelism with the surface can be improved. Therefore, the electrolytic action on the surface of the grindstone can be generated more uniformly, so that the processing quality can be further improved. In this case, 3
Sets or more of positioning means and spacing detecting means,
By arranging in a plane with respect to the facing region between the grinding wheel and the electrode (arranging the positioning position so as not to be arranged on a straight line), positioning can be performed in a plane, so that the grinding wheel surface and the electrode surface are parallel. The degree can be further increased.

In each of the above inventions, the second positioning means and the interval detecting means may rotate the second positioning means and the distance detecting means.
It is preferable that the positioning portion is configured to be movable, and is configured by a rotary gauge capable of measuring at least a position change amount of the second positioning portion.

In each of the above inventions, it is preferable that the electrolytic solution is supplied from an opening provided on the surface of the electrode facing the grindstone to a region facing the grindstone and the electrode.

According to the present invention, in addition to the accurate positioning of the facing distance between the grindstone and the electrode, the electrolytic solution is supplied from the opening formed on the surface of the electrode facing the grindstone, so that the electrolytic solution can be further improved. Since the fluid flows smoothly and is supplied to the grindstone surface, the electrolytic action of the grindstone can be more uniformly and smoothly generated.

In the present invention, it is preferable that a plurality of the openings are formed in a dispersed state on the surface of the electrode.

According to the present invention, since a plurality of openings are formed in a dispersed state on the surface of the electrode, a more uniform electrolytic action can be produced over the region where the grinding wheel and the electrode face each other. .

[0024]

Next, an embodiment of an electrolytic in-process dressing apparatus according to the present invention will be described in detail.

[Basic Configuration] First, the basic configuration of an apparatus common to both the first and second embodiments described below will be described. FIG. 1 is a schematic schematic perspective view showing an apparatus structure common to each embodiment of the present invention, and FIG. 2 is a schematic schematic sectional view of the same apparatus. In this device,
The disc-shaped wheel head 2 is configured to be rotatable about a rotation shaft 2a. A ring-shaped grinding wheel 4 is provided on one side of the grinding wheel base 2
Is attached. The grindstone 4 is a conductive grindstone in which abrasive grains are embedded in a conductive material as described later. A part of the grindstone 4 is arranged so as to overlap the turntable 6 in a plane, and the turntable 6
Is configured to be rotatable about a rotation shaft 6a. A holding jig 10 is mounted and fixed on the surface of the turntable 6.
A work 20 such as a quartz wafer is placed on the surface of the holding jig 10.
Is held by suction. The surface of the work 20 comes into contact with the surface of the grinding wheel 4 and undergoes a grinding process as described later. The rotation axes of the wheel head 2 and the turntable 6 are configured to be parallel to each other. The grinding device may be relatively moved while the grinding wheel 4 and the holding jig 10 are in contact with each other. The configuration described below allows the device configuration to be described below.

An electrode 8 formed in an arc shape is formed on a portion of the ring-shaped grindstone 4 not overlapping the turntable 6 in a plane.
Is a predetermined interval, that is, the gap d between the electrodes shown in FIG.
Are opposed to each other. The gap d between the electrodes is the whetstone 4
And the distance between the surface of the electrode 8 and the surface of the electrode 8 facing the surface. The electrode 8 is made of a conductive material, for example, a metal.
The electrode 8 is fixed to the electrode mounting member 7 shown in FIG.

A coolant supply nozzle 9 supplies an electrolytic coolant EC, which is a conductive electrolytic solution and also serves as a coolant, to the opposing region between the grindstone 4 and the electrode 8 from the side. I have. It is preferable that a plurality of coolant supply nozzles 9 are arranged in the direction in which the electrode 8 extends as shown in FIG. The electrolytic coolant is basically an electrolytic solution supplied between the grindstone 4 and the electrode 8, but the same coolant is supplied to the grindstone 4 and the holding jig 1.
It is desirable to supply also to the grinding part between the workpiece 20 fixed on the zero. However, another coolant (such as one having only a cooling function) may be supplied to the grinding unit.

As shown in FIG. 2, the rotating shaft 2a of the grinding wheel head 2
Is formed with a cylindrical conductive connecting portion 2b having a surface having good electric contact properties. The power supply 14
A positive potential is applied through the power supply brush 15 pressed against the conductive connection portion 2b, and a negative potential is applied to the electrode 8. The power supply 14 is a DC pulse power supply.

As the grinding wheel 4, diamond, CBN
Abrasive grains such as (tetragonal boron nitride) and various metal oxides are mixed with a conductive binder such as a metal bond (metal binder) and solidified, for example, sintered at a high temperature (1000 ° C. or higher). Can be used. As the metal bond, cast iron, bronze, nickel, cobalt, or the like can be used. Abrasive concentration (degree of concentration:
(JIS standard) is preferably about 50 to 200, and particularly preferably 50 to 100. The grain size of the abrasive grains is appropriately set according to the application. However, when hard abrasive grains such as diamond and CBN are used, when a mirror surface processing is required such as a quartz wafer, # 4000-
It is preferably about # 10000, and when using relatively soft abrasive grains other than the above, # 2000 to # 400
It is preferably about 0. The average particle size of # 4000 corresponds to about 4 μm.

In this device, the rotating shaft 2a and the rotating shaft 6a
The workpiece 20 fixed on the holding jig 10 is ground by the grindstone 4 by rotationally driving. At the same time, the grindstone 4 is electrolyzed by the electrolytic coolant EC based on the electric power supplied from the power supply 14, so that the metal bond in the grindstone 4 is dissolved, and the abrasive grains embedded in the metal bond are exposed. When a current flows between the grindstone 4 and the electrode 8 and the metal bond dissolves, the abrasive grains are exposed and a so-called grindstone dressing is performed. A dynamic film is formed, and the amount of current decreases rapidly and the elution of metal bonds also decreases. Grinding proceeds in this state, and when the abrasive grains are worn by the grinding of the work 20, the passive film is eventually broken through by the grinding action. When the passivation film is broken, a current flows again, the metal bond elutes into the electrolytic solution, and the abrasive grains again protrude onto the surface of the grindstone 4. By repeating such an operation, in the electrolytic in-process dressing process, the grinding proceeds while the dressing of the grindstone is always performed, so that clogging hardly occurs even when using abrasive grains having a fine particle size, The grinding can be performed efficiently, and the grinding can be performed quickly and in a stable state.

[First Embodiment] Next, referring to FIGS. 3 and 5, a detailed structure of a first embodiment of an electrolytic in-process dressing apparatus according to the present invention will be described. First
The schematic configuration of the embodiment is as shown in FIGS. 1 and 2 above, and the same portions are denoted by the same reference numerals and description thereof will be omitted.

FIG. 3 is a plan view (a) and a front view (b) showing the electrode mounting structure of the present embodiment. Here, the front view (b) shows the electrode 8 and the mounting structure thereof as viewed from the inside of the arc shape of the grinding wheel 4 (the rotation center side of the grinding wheel base 2). A support 11 fixed to a base (not shown) such as an apparatus frame is provided with a groove-shaped guide portion 11a extending in a vertical direction (vertical direction). The portion 7b is engaged so that it can move up and down. The electrode mounting member 7 is provided with the electrode support 7a for supporting the electrode 8 as described above.
A gauge mounting part 12 is fixed to the lower part of the support 11 substantially horizontally, and the gauge mounting part 12 extends below the electrode mounting member 7. A rotary gauge (micrometer) 13 for gap adjustment is mounted on the gauge mounting section 12. The rotary gauge 13 rotates the rotary operation unit 13a to rotate the rotary operation unit 1 with respect to the scale unit 13b.
As 3a moves, the measuring axis 13c moves in and out in the axial direction, and the moving distance of the measuring axis 13c in the axial direction or the position of the tip of the measuring axis 13c can be read based on the positional relationship between the rotary operation section 13a and the scale section 13b. Is a known rotary gauge. The tip of the measurement shaft 13c contacts the lower surface of the electrode mounting member 7 from below, and supports the electrode mounting member 7. Therefore, the electrode 7 and the electrode 8 supported by the electrode 7 are configured to move up and down along the guide portion 11a of the column 11 by rotating the rotary operation portion 13a of the rotary gauge 13.

The through holes 7c and 8 penetrate vertically through the electrode mounting member 7 and the electrode 8 at positions corresponding to each other, and communicate with each other.
b is formed, and a leading end of a coolant tube 16 made of a flexible tube or the like is introduced into the through hole 7c from below. When the above-mentioned electrolytic coolant EC is supplied from the coolant tube 16, the electrolytic coolant EC is supplied from a through hole 8 b opened in the surface 8 a of the electrode 8 to a region opposed to the grinding wheel 4 and the electrode 8.

In the present embodiment, as shown in FIG. 5 (a), the rotation operating portion 13a of the rotary gauge 13 is rotated so that the measurement shaft 13c protrudes upward, and the electrode mounting member is moved by the tip of the measurement shaft 13c. 7 is pushed upward so that the surface 8a of the electrode 8 comes into contact with the surface 4a of the grinding wheel 4 facing the electrode 8. Next, the scale of the scale portion 13b of the rotary gauge 13 in this state is read, and the tip of the measurement shaft 13c is set based on the read value by a preset gap d between the electrodes as shown in FIG. The rotation operation unit 13a is rotated in the reverse direction so that moves downward. By doing so, the surface 8 a of the electrode 8 and the surface 4
The gap d between the electrodes can be set accurately.

In the present embodiment, the rotary gauge 13
Thus, the positioning means for positioning the electrode 8 in the vertical direction and the interval detecting means for measuring the gap d between the electrodes are integrally formed, but they may be formed by separate members or separate portions. For example, a rotary screw structure for positioning the electrode 8 may be provided, and separately from this, a measurement scale for measuring the position of the electrode 8 may be formed on the surface of the support 11, for example.

[Second Embodiment] Next, the structure of a second embodiment according to the present invention will be described with reference to FIGS. Also in the second embodiment, the basic configuration is provided with the structure shown in FIGS. 1 and 2 as in the case of the above-described first embodiment. I do.

In this embodiment, as shown in FIG.
Since the same support 11, gauge mounting part 12, and rotary gauge 13 as those of the embodiment are provided, their description is omitted. This embodiment is different from the first embodiment in that a large number of openings 8c are formed on the surface 8a of the electrode 8 as shown in FIG. The openings 8c are formed so as to be distributed almost uniformly on the surface 8a. The opening 8c communicates with a coolant accommodating portion 8d formed inside the electrode 8. The coolant accommodating portion 8d is an internal space having a shape extending in a plane arc substantially similar to the outer shape of the electrode 8. The above-mentioned electrolytic coolant EC is supplied to the coolant accommodating portion 8d from a coolant tube 17 formed of a flexible tube or the like connected to the electrode 8. The electrolytic coolant EC supplied to the coolant accommodating portion 8c is supplied to the opening 8
The air is blown out from c toward the area where the grindstone 4 and the electrode 8 face each other.

In this embodiment, a plurality of openings 8c are formed on the surface 8a of the electrode 8 facing the grindstone 4 as described above, and these openings 8c are dispersed on the surface 8a. Since the electrolytic coolant is supplied from 8c, the electrolytic coolant can be uniformly and sufficiently supplied to the inter-electrode gap region as compared with the case where the electrolytic coolant is supplied from the outside only by the supply nozzle 9 described above. Become. Further, the electrolytic coolant can be supplied to the opposed region more uniformly than in the first embodiment in which the electrolytic coolant is supplied from the opening 8b on the surface of the electrode 8.

In this embodiment, as shown in FIG. 4 (b), two rotary gauges 18, 18 are provided on both sides of a rotary gauge 13 mounted on the gauge mounting portion 12 in the same manner as described above.
19 is different from the first embodiment in that the mounting member 19 is attached. These rotary gauges 18 and 19 basically have exactly the same structure as the rotary gauge 13, and the rotary operation unit 1 having the same function as each component of the rotary gauge 13.
8a, 19a, scale parts 18b, 19b and measuring axis 18
c, 19c. In this case, as shown in FIG. 4 (b), the configuration is such that the distal ends of the measurement shafts 13 c, 18 c, 19 c of the three rotary gauges 13, 18, 19 can respectively contact the lower surface of the electrode mounting member 7. Have been.

Next, a method of adjusting and setting the gap between the electrodes in the present embodiment having the above three rotary gauges will be described. First, as shown in FIG.
Rotary operation parts 13a, 1 of rotary gauges 13, 18, 19
8a, 19a are rotated to measure the axes 13c, 18c, 19
c, and projecting the tip of the electrode upward, the electrode mounting member 7 and the electrode 8
And the surface 8 a of the electrode 8 is brought into contact with the surface 4 a of the grindstone 4. At this time, the three measurement axes 13c, 18c, 1
9c is made to abut on the lower surface of the electrode mounting member 7. Then, the scales of the scale portions 18b and 19b of the right and left rotary gauges 18 and 19 are read. Next, the rotary operation parts 18a, 19a of the left and right rotary gauges 18, 19
Is rotated in the reverse direction to lower the distal ends of the measurement shafts 18c and 19c, and the distal ends are respectively moved downward by a preset inter-electrode gap d from the previously read value. After the operation of the left and right rotary gauges 18 and 19 is completed, the rotation operation unit 13a of the central rotary gauge 13 is rotated in the reverse direction to lower the tip of the measurement shaft 13c. Eventually, as shown in FIG. 6 (b), the tip of the measurement shaft 13c becomes the measurement shaft 18c, 19c of the left and right rotary gauges 18, 19.
The electrode mounting member 7 and the electrode 8 are moved below the tip of the measuring shaft 18 of the left and right rotary gauges 18 and 19.
c, 19c.

In this embodiment, since the gap between the electrodes between the grindstone 4 and the electrode 8 is positioned by the tips of the two measuring axes 18c and 19c, the gap between the surface 4a of the grindstone 4 and the surface 8a of the electrode 8 is determined. The parallelism can be set with higher accuracy than in the first embodiment. Therefore, the electric field applied to the surface 4a of the grindstone 4 becomes more uniform, and the uniformity of the electrolytic action of the grindstone 4 can be improved.

In the present embodiment, three rotary gauges are used. One of them is a set screw which is merely a positioning means, and the remaining two rotary gauges are used to obtain the parallelism of the gap between the electrodes. May be adopted. Alternatively, only two rotary gauges may be provided, and the parallelism of the gap between the electrodes may be obtained by these rotary gauges. Further, although the positioning is performed at only one point as in the first embodiment, the gap between the electrodes can be set even if, for example, one set screw and one rotary gauge are used.

In the case where three sets of rotary gauges are used as in the above embodiment, the three sets of rotary gauges are not arranged on the same straight line, and the three sets of rotary gauges are positioned at the apex of the triangle. By configuring to be placed in
The electrode 8 can be positioned in a plane. Therefore, the parallelism between the surface 4a of the grindstone 4 and the surface 8a of the electrode 8 can be further increased. For example, in the example shown in FIG. 6, the rotary gauge 13 is connected to the left and right rotary gauges 18 and 19.
Is shifted in the direction perpendicular to the plane of the drawing from the straight line connecting the three lines, three-dimensional support by three rotary gauges becomes possible. In this case, finally, as shown in FIG. 6 (b), with the electrode mounting member 7 and the electrode 8 being supported by the measurement shafts 18c, 19c of the left and right rotary gauges 18, 19, the central rotary gauge is used. 13 measuring axes 13
As for c, as shown in FIG. 6 (a), the scale is read in a state where the scale is in contact with the lower surface of the electrode mounting member 7, and the measuring axis 13c is temporarily moved from this as shown in FIG. 6 (b). The electrode mounting member 7 is supported by the measurement shafts 18c and 19c by lowering, and then, as shown by a dotted line in FIG. 6B, the measurement shaft 13c is lowered by the inter-electrode gap d from the above read value. The measurement axis 13c may be returned to the upper state. By doing so, the electrode mounting member 7
The electrode 8 is supported at three points of the measurement axes 13c, 18c, and 19c.

The work 20 was subjected to a grinding test using the above-mentioned electrolytic in-process dressing apparatus. In addition,
Before processing the work 20, the setting work of the electrode gap d shown in FIGS. 2 to 6 was performed. The work 20 is obtained by slicing a crystal lump to a thickness of about 260 μm,
Create a square wafer and roughly grind the front and back surfaces to about 200
After forming to a thickness of μm, the wafer was suction-held on the holding jig 10 and ground by the above-mentioned apparatus. In the holding jig 10, the suction surface for the work 20 is constituted by an exposed surface of a holding member made of a porous material such as ceramics, and the holding member is attached to a concave portion of the holding jig 10. By exhausting through the holding member, the work 20 is configured to be suction-held on the exposed surface thereof. The grindstone used in this test was formed by using diamond grains of # 4000 as abrasive grains, and setting the concentration of the abrasive grains to about 100 by a metal bond obtained by mixing cast iron and bronze.

As a result, the above-mentioned quartz wafer is finally
The thickness could be reduced to a thickness of μm. The surface of the crystal wafer after the grinding had a sufficient mirror surface. In addition, when the crystal wafer after grinding was removed from the holding jig by the method shown in FIG. 5, it could be easily removed without any problem. The processing of such a thin quartz wafer is completely impossible with the lapping processing used in the conventional manufacturing process of the quartz oscillator.
In addition, the processing according to the present embodiment is essentially a grinding processing, and a dressing action of the grindstone always occurs, so that a sufficient processing speed can be obtained. Further, there is an advantage that the processing can be performed without concern for a wafer crack or the like which may be caused by the lapping processing. In addition, in the processing by the conventional lapping method, if the polishing processing is not performed stepwise by a plurality of steps, for example, rough processing, intermediate processing, and finishing processing, a sufficiently flat and reduced surface roughness of the processed surface can be achieved in a short time. However, according to the apparatus of the present embodiment, it was possible to obtain a wafer surface sufficiently quickly and sufficiently flat and close to a mirror surface in a single step.

Further, the effect of accurately setting the gap between the electrodes by the configuration of each of the above embodiments is extremely large, and both the improvement of the quality of the ground surface and the improvement of the grinding speed can be achieved. In particular, by using the apparatus of the second embodiment, the uniformity of the gap between the electrodes can be obtained,
Compared to the apparatus of the first embodiment, it is possible to realize both improvement of the quality of the ground surface and improvement of the grinding speed.
In particular, in the case of a work that is brittle and easily broken, such as a very thin quartz wafer as described above, by ensuring accurate setting of the gap between the electrodes and high uniformity as in the present embodiment, It has been found that since the flatness and homogeneity of the surface can be ensured, breakage of the work can be prevented, and the processing can be performed safely and reliably.

Incidentally, the electrolytic in-process dressing apparatus of the present invention is not limited to the above-described illustrated example, and it goes without saying that various changes can be made without departing from the spirit of the present invention. For example, in each of the above embodiments, the gap between the electrodes is adjusted by moving the electrodes, but the gap between the electrodes may be adjusted by moving the grindstone. It may be moved.

[0048]

As described above, according to the present invention,
At least one of the grindstone and the electrode is configured to be movable so that the facing distance can be changed by the guide structure, at least one of the grindstone and the electrode is positioned by the positioning means, and the facing distance or a change amount thereof can be measured by the spacing detecting means. With this configuration, the opposing distance between the grindstone and the electrode can be easily and accurately set by positioning while measuring by the distance detecting means. Therefore, the electrolytic action can be suitably generated, and the processing quality can be improved. In addition, the processing speed can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a basic configuration common to each embodiment of an electrolytic in-process dressing apparatus according to the present invention.

FIG. 2 is a schematic configuration sectional view showing a basic configuration common to each embodiment.

FIGS. 3A and 3B are an enlarged plan view (a) and an enlarged front view (b) showing a structure for setting a gap between electrodes in the electrolytic in-process dressing apparatus according to the first embodiment of the present invention.

FIG. 4 is an enlarged plan view (a) and an enlarged front view (b) showing a structural portion (electrode support structure) for setting a gap between electrodes of the electrolytic in-process dressing apparatus according to the first embodiment of the present invention. It is.

FIGS. 5A and 5B are explanatory diagrams illustrating an operation of setting a gap between electrodes according to the first embodiment. FIGS.

FIGS. 6A and 6B are explanatory diagrams illustrating an operation of setting a gap between electrodes according to the second embodiment.

[Explanation of symbols]

 2 Wheel head 4 Wheel 6 Rotary table 7 Electrode mounting member 8 Electrode 9 Coolant supply nozzle 10 Holding jig 11 Support 12 Gauge mounting part 13, 18, 19 Rotary gauge 13a, 18a, 19a Rotary operating part 13b, 18b, 19b Scale Part 13c, 18c, 19c Measurement axis 20 Work

Claims (8)

[Claims] A work, a grindstone configured to be in contact with the work, and having abrasive grains embedded in a conductive base material, and a surface portion of the grindstone that is not in contact with the work at a predetermined interval. Opposing electrodes, a power supply for applying a voltage between the grinding wheel and the electrode, an electrolyte supply unit for supplying an electrolyte between the grinding wheel and the electrode, and the grinding wheel and the workpiece are relatively positioned. And a driving unit configured to move the workpiece to the grindstone so that the workpiece can be processed by the grindstone. Electrolytic in-process dressing for processing the work while eluting and setting the conductive base material from the grindstone by electrolytic action. In the processing apparatus, a guide structure configured to be movable at least one of the grindstone and the electrode so as to be configured to be able to change a facing distance between the grindstone and the electrode, Pole of at least one of the by positioning the settable positioning means the opposing distance, electrolytic in-process dressing processing apparatus characterized by comprising a detectable gap detecting means said counter interval or the amount of change. 2. The in-process in-process dressing apparatus according to claim 1, wherein a plurality of the positioning means and the interval detecting means are provided at different positions where the grindstone and the electrode face each other. 3. The rotating operation according to claim 1, wherein the positioning means and the interval detecting means include a positioning part for directly or indirectly abutting on at least one of the whetstone and the electrode for positioning. An electrolytic in-process dressing apparatus, characterized in that the positioning section is configured to be movable by means of a rotary gauge capable of measuring at least the amount of change in the position of the positioning section. 4. The first positioning means according to claim 1 or 2, further comprising a first positioning portion for directly or indirectly abutting at least one of the whetstone and the electrode for positioning. A second positioning means having a second positioning portion configured to be able to set a position independently with respect to the portion and directly or indirectly abutting on at least one of the whetstone and the electrode for positioning. An electrolytic in-process dressing apparatus, wherein the detecting means is configured to measure at least a position change amount of the second positioning section. 5. The plurality of second positioning means according to claim 4, wherein a plurality of said second positioning means are provided at different opposing positions of said grinding wheel and said electrode, and at least a position of said second positioning part provided in each of said plurality of second positioning means. An electrolytic in-process dressing apparatus, comprising: a plurality of the interval detecting means configured to measure a change amount independently of each other. 6. The second positioning unit and the interval detection unit according to claim 4, wherein the second positioning unit and the interval detection unit are configured to be able to move the second positioning unit by a rotation operation, and to change at least a position of the second positioning unit. An electrolytic in-process dressing apparatus characterized by comprising a rotary gauge capable of measuring an amount. 7. One of claims 1 to 6
In the paragraph, the electrolytic in-process dressing is configured to supply the electrolytic solution into a region facing the grinding wheel and the electrode from an opening provided on the surface of the electrode facing the grinding wheel. Processing equipment. 8. The electrolytic in-process dressing apparatus according to claim 7, wherein the plurality of openings are formed in a dispersed state on the surface of the electrode.