JP2022074386A - Porous chuck table manufacturing method and porous chuck table - Google Patents

Abstract

To fix a porous plate to a frame body without use of an adhesive.SOLUTION: A porous chuck table manufacturing method comprises: a table body preparation step at which a porous plate made of a glass is fitted in a recess of a non-porous frame body made of a glass, thereby forming a table body; and a heating step at which after the table body preparation step, the table body is heated at a temperature of a softening point or more and less than a melting point of the frame body, a facing area of the recess of the frame body, that faces an outside surface of the porous plate, is softened, thereby deforming the facing area of the recess so as to follow an irregularity of the outside surface of the porous plate, and tightly adhering and fixing the same.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for manufacturing a porous chuck table having a porous porous plate made of glass, and the porous chuck table.

In order to process a workpiece such as a semiconductor wafer, a chuck table having a holding surface for sucking and holding the workpiece is known. A typical chuck table has a disk-shaped frame made of metal or non-porous ceramics.

A disk-shaped recess is formed in the upper part of the frame, and a disk-shaped plate (that is, a porous plate) made of porous ceramics is fixed to the recess. The porous plate is usually fixed to the frame with an adhesive (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 5-23941

However, the fixing force of the adhesive may decrease due to the liquid sucked into the porous plate, the negative pressure and the positive pressure repeatedly applied to the porous plate, and the porous plate may come off from the frame. The present invention has been made in view of the above problems, and an object of the present invention is to fix a porous plate to a frame without using an adhesive.

According to one aspect of the present invention, which is a method for manufacturing a porous chuck table, a porous porous plate made of glass is fitted into a recess of a non-porous frame made of glass to fit the table. After the table body preparation step for forming the body and the table body preparation step, the table body is heated at a temperature equal to or higher than the softening point of the frame body and lower than the melting point, and the porous plate in the concave portion of the frame body is heated. A porous chuck table comprising a heating step that softens the facing region facing the outer surface to deform the facing region of the recess so as to imitate the unevenness of the outer surface of the porous plate so as to adhere and fix the porous plate. A manufacturing method is provided.

Preferably, in the heating step, the facing region of the frame is softened before the outer surface of the porous plate facing the facing region.

Preferably, in the method for manufacturing a porous chuck table, after the table body preparation step, the upper surface of the porous plate and the upper surface of the frame are ground to be flush with each other, and a holding surface for sucking and holding the workpiece is held. A holding surface forming step for forming the above is further provided.

According to another aspect of the present invention, the frame is provided with a glass and porous porous plate and a glass and non-porous frame having a recess into which the porous plate is fitted. The facing region of the concave portion facing the outer surface of the porous plate follows the unevenness of the outer surface of the porous plate and has a close contact region in close contact with the unevenness of the outer surface of the porous plate. A table is provided.

In the method for manufacturing a porous chuck table according to one aspect of the present invention, a table body in which a porous porous plate made of glass is fitted into a disk-shaped recess of a non-porous frame made of glass is formed. By heating at a temperature above the softening point of the frame and below the melting point to soften the facing region of the frame facing the outer surface of the porous plate, the facing region of the recesses follows the unevenness of the outer surface of the porous plate. It is provided with a heating step that is deformed so as to be brought into close contact and fixed. Therefore, the porous plate can be fixed to the frame without using an adhesive.

It is a flow chart of the manufacturing method of the porous chuck table which concerns on 1st Embodiment. FIG. 2A is a cross-sectional view of a frame body and a porous plate, and FIG. 2B is a cross-sectional view of a table body. It is a figure which shows the holding surface formation step. It is a figure which shows the heating step. FIG. 5A is a cross-sectional view of the vicinity of the facing region before the heating step, and FIG. 5B is a cross-sectional view of the vicinity of the facing region after the heating step. It is sectional drawing of the porous chuck table after a heating step. It is a flow chart of the manufacturing method of the porous chuck table which concerns on 2nd Embodiment. It is a partial cross-sectional side view of a laser processing apparatus. It is a partial cross-sectional side view of a grinding apparatus.

An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a flow chart of a manufacturing method of the porous chuck table 8 (see FIG. 6) according to the first embodiment. In the manufacturing method of the present embodiment, first, the frame body 2 and the porous plate 4 (see FIG. 2A) form the table body 6 (see FIG. 2B) (table body preparation step S10).

FIG. 2A is a cross-sectional view of the frame body 2 and the porous plate 4. The frame body 2 is a non-porous body formed of soda glass (soda-lime glass) having a disk shape and being transparent to visible light. However, the frame 2 may be made of various glasses such as borosilicate glass and quartz glass.

A disk-shaped recess 2b having a diameter smaller than the outer diameter of the frame 2 is formed on the upper surface 2a side of the frame 2. The recess 2b includes a circular bottom surface 2b ₁ and a curved side surface 2b ₂ . At the center of the bottom surface 2b ₁ of the recess 2b, a substantially cylindrical flow path 2d ₁ penetrating to the lower surface 2c of the frame body 2 is formed.

Further, concentric flow paths 2d ₂ , 2d ₃ , and 2d ₄ surrounding the flow paths 2d ₁ are formed on the bottom surface 2b ₁ of the recess 2b. The flow paths 2d ₂ , 2d ₃ , and 2d ₄ are shallower than the flow path 2d ₁ , and communicate with the flow path 2d ₁ via a substantially cross-shaped communication path (not shown) when the bottom surface 2b ₁ is viewed from above. are doing.

A table body 6 (see FIG. 2B) is formed by fitting a disk-shaped porous plate 4 having substantially the same diameter as the recess 2b into the recess 2b. FIG. 2B is a cross-sectional view of the table body 6. The porous plate 4 has a substantially circular upper surface 4a and a lower surface 4c, and a curved side surface 4b, respectively.

The porous plate 4 is made of substantially the same glass material (soda glass in this embodiment) as the frame body 2, but the porous plate 4 has a plurality of glass grains 5 (FIGS. 5 (A) and 5 (B)). (See) is a porous body constructed by connecting them to each other.

Each glass grain 5 is spherical and has substantially the same particle size. The glass particles 5 are preferably dense particles having no bubbles. Such glass grains 5 can be produced, for example, by spray drying (spray drying).

The spray dryer (spray dryer) has a nozzle or a disc for atomizing the undiluted solution of glass. By exposing the undiluted solution of glass that has been atomized into spheres due to surface tension or the like to hot air supplied to the drying chamber, the atomized undiluted solution is solidified to become spherical and uniform glass particles 5.

In this embodiment, glass particles 5 having a particle size of 3 μm or more and 4 mm or less are used. The particle size of the glass particles 5 is more preferably 5 μm or more and 300 μm or less, and further preferably 30 μm or more and 200 μm or less.

The particle size of the glass particles 5 has a predetermined variation according to the Gaussian distribution. For example, when the particle size of the glass particles 5 is a predetermined value of 100 μm or less, a particle group having a standard deviation of 5 μm or less is used. Further, for example, when the particle size of the glass particles 5 is a predetermined value of 101 μm or more and 300 μm or less, a particle group having a standard deviation of 10 μm or less is used.

In order to manufacture the porous plate 4, first, a plurality of glass particles 5 are placed in a mold (not shown) having a disk-shaped recess and sealed with a lid plate (not shown). Then, the mold, the lid plate and the glass particles 5 are placed in a firing furnace and fired at a predetermined temperature of 600 ° C. or higher and 1300 ° C. or lower.

In the present embodiment, the glass particles 5 are fired at a predetermined temperature of 700 ° C. or higher and 800 ° C. or lower for a predetermined time of about 30 minutes or more and about 3 hours or less. By firing, as shown in FIGS. 5 (A) and 5 (B), a porous plate in which spherical glass grains 5 adjacent to each other are partially connected while leaving pores 7 in the gaps between the glass grains 5. 4 can be formed.

The longer the time for firing the glass particles 5, the longer the time for the glass material to become fluid, so that the contact area between the glass particles 5 increases and the porosity decreases. For example, the porosity of the porous plate 4 having a firing time of 3 hours is lower than the porosity of the porous plate 4 having a firing time of 30 minutes.

The porosity of the porous plate 4 is, for example, 5% or more and 40% or less. In the present embodiment, the porosity of the porous plate 4 is 30% or more and 40% or less. However, the porosity may be 5% or more and 20% or less, 20% or more and 30% or less, and the like.

The porosity can be appropriately adjusted by not only the firing time but also the temperature and pressure at the time of firing, the amount of frit added to the glass particles 5, and the like. The frit is a powder formed of the same glass material as the glass grain 5 and having a diameter smaller than that of the glass grain 5.

The porosity of the porous plate 4 is appropriately adjusted according to the suction force acting on the porous chuck table 8. For example, when the porous plate 4 is connected to a suction source 34 (see FIG. 8) such as an ejector via a flow path 2d ₁ or the like of the frame body 2, the higher the porosity, the higher the suction force on the upper surface 4a. Therefore, the lower the porosity, the lower the adsorption force on the upper surface 4a.

However, the lower the porosity, the larger the area of the upper surface 4a that supports the workpiece 11 (see FIGS. 8 and 9). Therefore, for example, when the workpiece 11 is cut, the workpiece 11 is covered. There is an advantage that chipping is less likely to occur on the suction surface.

The size of the pores 7 when the porous plate 4 is formed of the glass particles 5 is uniform compared to the size of the pores when the porous plate is formed of the ceramic particles having irregular sizes. , The suction force becomes substantially uniform on the upper surface 4a of the porous plate 4. Therefore, it is possible to provide a stable holding force with relatively little in-plane variation.

As a result, for example, when the workpiece 11 such as a semiconductor wafer is cut and divided into a plurality of chips, the movement of the chips is reduced. Therefore, it is possible to suppress the occurrence of corner cracks (chips at the corners) on the back surface of the chip, which is generated by the movement of the chip. In addition, it is possible to suppress the occurrence of chipping on the back surface of the chip.

In addition, since the porous plate 4 is formed of spherical glass grains 5 instead of elongated abrasive grains (that is, so-called angular shape), processing including processing chips generated by processing the workpiece 11 is included. Even if the liquid enters the inside of the porous plate 4, it is difficult for the work chips to get caught in the inside of the porous plate 4.

Therefore, compared to the case where the porous plate is formed of the angular abrasive grains, the porous plate 4 discharges the work chips relatively smoothly. Therefore, it is possible to reduce the risk that the inside of the porous plate 4 is clogged with work chips and the suction force of the porous plate 4 is reduced.

By the way, after forming the porous plate 4 by connecting the glass grains 5 to each other, in order to correct the size, shape, etc. of the porous plate 4, the upper surface 4a, the side surface 4b, and the lower surface 4c of the porous plate 4 are subjected to. Grinding, polishing, etc. may be performed as appropriate.

In the present embodiment, after the table body preparation step S10, the upper surface 2a of the frame body 2 and the upper surface 4a of the porous plate 4 are ground to be flush with each other by using the grinding device 10 (see FIG. 3). Then, the holding surface 8a (see FIG. 6) is formed (holding surface forming step S20). FIG. 3 is a diagram showing a holding surface forming step S20.

The grinding device 10 has a general chuck table 12. The chuck table 12 includes a disk-shaped frame made of non-porous ceramics. A disk-shaped recess (not shown) is formed in the upper part of the frame, and a disk-shaped porous plate (not shown) made of porous ceramics is fixed to the recess with an adhesive. ..

The adhesive is mainly made of resin and binds the frame to the porous plate by at least one of chemical and physical forces. As the adhesive, an epoxy-based adhesive, an acrylic-based adhesive, a urethane-based adhesive, or the like is typically used.

A flow path (not shown) is formed in the frame of the chuck table 12. One end of the flow path is connected to a suction source 14 such as an ejector, and the other end of the flow path is connected to the lower surface of the porous plate. When the suction source 14 is operated, a negative pressure is transmitted to the upper surface of the porous plate.

The upper surface of the frame and the upper surface of the porous plate are flush with each other, and form a holding surface 12a for sucking and holding the workpiece 11. The table body 6 is arranged on the holding surface 12a so that the upper surface 2a of the frame body 2 and the upper surface 4a of the porous plate 4 face upward.

A resin-made protective sheet 16 is attached to the lower surface 2c of the frame body 2, and the table body 6 is sucked and held by the holding surface 12a via the protective sheet 16. A rotation drive mechanism (not shown) is connected to the lower part of the chuck table 12. The chuck table 12 is rotated around a predetermined rotation shaft 12b substantially parallel to the Z-axis direction by a rotation drive mechanism.

A grinding unit 18 is arranged above the chuck table 12. The grinding unit 18 has a cylindrical spindle housing (not shown) arranged along the Z-axis direction (height direction, vertical direction, grinding feed direction).

A grinding feed mechanism (not shown) is connected to the spindle housing, and the grinding unit 18 is moved along the Z-axis direction by the grinding feed mechanism. A part of the columnar spindle 20 is rotatably housed in the spindle housing.

A rotary drive source (not shown) such as a motor is connected to the upper end of the spindle 20, and a disk-shaped wheel mount 22 is fixed to the lower end of the spindle 20. A grinding wheel 24 having substantially the same diameter as the wheel mount 22 is mounted on the lower surface of the wheel mount 22.

The grinding wheel 24 includes an annular wheel base 24a made of a metal material such as aluminum. The upper surface side of the wheel base 24a is mounted on the wheel mount 22, and a plurality of grinding wheels 24b are fixed to the lower surface side of the wheel base 24a.

The plurality of block-shaped grinding wheels 24b are arranged in an annular shape in the circumferential direction of the lower surface of the wheel base 24a so that a gap is provided between the adjacent grinding wheels 24b.

The grinding wheel 24b is formed by mixing, for example, abrasive grains such as diamond and cBN (cubic boron nitride) with a binder such as metal, ceramics, and resin. However, there are no restrictions on the binder and abrasive grains, and they are appropriately selected according to the grinding target.

In the holding surface forming step S20, first, the lower surface 2c side of the table body 6 is sucked and held by the holding surface 12a. After that, with the grinding wheel 24 rotated around the spindle 20, the grinding unit 18 is grounded and fed, and the upper surfaces 2a and 4a are ground with the grinding wheel 24b. After grinding the upper surfaces 2a and 4a, the table body 6 is washed with water, ultrasonic waves, or the like to remove grinding debris generated by grinding.

By the holding surface forming step S20, the upper surfaces 2a and 4a become substantially flat. The fact that the upper surfaces 2a and 4a are substantially flat means that, for example, the center line average roughness Ra is 5.0 μm or less. Ra of the upper surfaces 2a and 4a of the present embodiment has a reference length (length of a constant portion extracted from the contour curve) of about 2.4 mm and 4.3 μm.

The flatness may be defined by using the maximum height Ry instead of the center line average roughness Ra. In this case, the fact that the upper surfaces 2a and 4a are substantially flat means that, for example, the maximum height Ry is 25 μm or less. The Ry of the upper surfaces 2a and 4a of the present embodiment has a reference length of about 2.4 mm and a reference length of 22.1 μm.

The flatness of the upper surface 4a of the porous plate 4 affects the processing of the workpiece 11. If the ratio of the pores 7 to the upper surface 4a composed of the glass particles 5 is large, the ratio of the area supporting the back surface 11b of the workpiece 11 becomes small, and chipping occurs on the back surface 11b side of the workpiece 11. It will be easier.

Since the porous plate 4 according to the present invention is formed of glass particles 5 having a hardness lower than that of the ceramic particles, the upper surface 4a is formed with a weaker force than when the porous plate formed of the ceramic particles is ground. Can be ground. Therefore, it is easy to flatten the upper surface 4a of the porous plate 4.

By using the substantially flat upper surface 4a, it is possible to suppress the occurrence of chipping on the back surface side of the chip manufactured by cutting the workpiece 11. For example, when the chip is a small rectangular chip having a side length of 1 mm or less, the porous plate 4 having a substantially flat upper surface 4a is particularly suitable.

After the holding surface forming step S20, the table body 6 is heated at a temperature equal to or higher than the softening point of the frame body 2 and lower than the melting point using the heating furnace 26 (see FIG. 4) (heating step S30). FIG. 4 is a diagram showing a heating step S30.

The heating furnace 26 is, for example, an electric furnace having an electric heating type heater. The temperature inside the heating furnace 26 is controlled to a predetermined temperature by a temperature control device (not shown) provided in the heating furnace 26.

The non-porous frame 2 softens at a predetermined temperature (eg, 600 ° C.). On the other hand, although the porous porous plate 4 is made of the same material as the frame body 2, it has pores 7, so that heat is less likely to be transferred than the frame body 2. Therefore, at a predetermined temperature, the non-porous frame 2 softens faster than the porous porous plate 4.

In the present embodiment, the table body 6 is arranged in the heating furnace 26, and the temperature inside the furnace is set to 500 ° C. or higher and 650 ° C. or lower under an atmospheric atmosphere. In this state, the table body 6 is heated for a predetermined time of about 30 minutes or more and about 3 hours or less.

In the heating step S30, a structure may be appropriately arranged so as to be in contact with the table body 6 for the purpose of optimizing the temperature distribution in the table body 6 and preventing deformation of the outer peripheral side surface of the frame body 2.

FIG. 5A is a cross-sectional view of the vicinity of the facing region 2e on the side surface 2b ₂ of the concave portion 2b of the frame body 2 before the heating step S30, and FIG. 5B is a concave portion of the frame body 2 after the heating step S30. It is sectional drawing in the vicinity of the facing area 2e on the side surface 2b ₂ of 2b.

In the heating step S30, of the bottom surface 2b ₁ and the side surface 2b ₂ of the recess 2b, the facing region 2e of the frame body 2 facing the side surface 4b and the lower surface 4c (outer surface) of the porous plate 4 is the side surface 4b and the side surface 4b of the porous plate 4. It softens faster than the lower surface 4c (outer surface). Therefore, the facing region 2e is greatly deformed as compared with the side surface 4b and the lower surface 4c (outer surface).

As shown in FIG. 5B, the facing region 2e of the side surface 2b ₂ facing the side surface 4b (outer surface) of the porous plate 4 is deformed to imitate the unevenness of the glass grain 5 and becomes the unevenness of the side surface 4b. It becomes a close contact area.

Further, the facing region of the bottom surface 2b ₁ facing the lower surface 4c (outer surface) of the porous plate 4 is also deformed to imitate the unevenness of the glass particles 5 and becomes a close contact region in close contact with the unevenness of the lower surface 4c. Specifically, the range of the bottom surface 2b ₁ excluding the flow paths 2d ₁ , 2d ₂ , 2d ₃ , and 2d ₄ is the close contact region.

As described above, in the heating step S30, the facing region of the frame body 2 is in close contact with the unevenness of the side surface 4b and the lower surface 4c (outer surface) of the porous plate 4, so that the porous plate 4 can be framed without using an adhesive. Can be fixed to 2.

FIG. 6 is a cross-sectional view of the porous chuck table 8 after the heating step S30. As described above, the upper surface 2a of the glass frame 2 and the upper surface 4a of the glass porous plate 4 serve as holding surfaces 8a for sucking and holding the workpiece 11 (see FIGS. 8 and 9). Function.

In the present embodiment, the unevenness of the minute glass particles 5 constituting the porous plate 4 is brought into close contact with the concave portion 2b of the frame body 2, so that the frame body 2 and the porous plate 4 can be attached to each other without using an adhesive such as resin. A physically fixed porous chuck table 8 can be manufactured.

Next, the second embodiment will be described. FIG. 7 is a flow chart of a manufacturing method of the porous chuck table 8 according to the second embodiment. In the second embodiment, after the table body preparation step S10, the heating step S30 is performed, and then the holding surface forming step S32 is performed.

This point is different from the first embodiment, but other points are the same as the first embodiment. Also in the second embodiment, since the facing region of the frame body 2 is in close contact with the unevenness of the side surface 4b and the lower surface 4c (outer surface) of the porous plate 4, the porous plate 4 is attached to the frame body 2 without using an adhesive. Can be fixed.

Next, an example of processing the workpiece 11 using the glass porous chuck table 8 will be described. First, the laser processing apparatus 30 provided with the porous chuck table 8 will be described. FIG. 8 is a partial cross-sectional side view of the laser processing apparatus 30.

A suction source 34 such as an ejector is connected to the flow path 2d ₁ of the frame body 2 via a solenoid valve 32. The negative pressure generated in the suction source 34 is transmitted to the holding surface 8a via the flow path 2d ₁ and the like. The workpiece 11 is sucked and held on the holding surface 8a via the protective tape 13 made of resin.

The workpiece 11 is, for example, a silicon wafer. On the surface 11a of the workpiece 11, a plurality of scheduled division lines (not shown) are set in a grid pattern. Devices (not shown) such as ICs (Integrated Circuits) are formed on the surface 11a side of each region partitioned by a plurality of scheduled division lines.

A θ table (not shown) for rotating the porous chuck table 8 is connected to the lower portion of the porous chuck table 8 around a rotation axis substantially parallel to the Z-axis direction. An X-axis moving mechanism (not shown) for moving the θ table and the porous chuck table 8 in the X-axis direction (machining feed direction) is connected to the lower part of the θ table.

Further, a laser beam irradiation unit 36 is arranged above the holding surface 8a. The laser beam irradiation unit 36 has a laser oscillator, a predetermined optical system, a condenser lens, and the like (all not shown), and is a pulsed laser having a wavelength (for example, 1064 nm) transmitted through the workpiece 11. The beam L is irradiated toward the holding surface 8a.

When the workpiece 11 is laser-machined, for example, first, the surface 11a side of the workpiece 11 is sucked and held by the holding surface 8a. Then, the orientation of the porous chuck table 8 is adjusted on the θ table so that one scheduled division line is substantially parallel to the X-axis direction.

Next, with the focusing point P of the laser beam L positioned at a predetermined depth position of the workpiece 11, the porous chuck table 8 is moved relative to the focusing point P in the X-axis direction. As a result, the modified region 15 is formed along the moving path of the condensing point P.

The modified region 15 is a region relatively fragile as compared with the region not irradiated with the laser beam L, and inside the workpiece 11, cracks extend from the modified region 15 to the front surface 11a and the back surface 11b. do.

As described above, in the porous chuck table 8, both the frame body 2 and the porous plate 4 are made of glass. Since the laser beam L having the wavelength in the infrared band described above passes through the porous chuck table 8, there is an advantage that the porous chuck table 8 is not damaged by the laser beam L.

Next, a grinding device 40 provided with a glass porous chuck table 38 will be described. FIG. 9 is a partial cross-sectional side view of the grinding device 40. The porous chuck table 38 has a holding surface 38a composed of an upper surface 2a of the above-mentioned frame body 2 and an upper surface 4a of the porous plate 4.

However, the outer peripheral portion of the bottom portion of the frame body 2 has an annular edge portion 2f. A plurality of through screw holes are formed discretely along the circumferential direction of the frame body 2 in the edge portion 2f. The porous chuck table 38 is fixed to the rotary drive mechanism 42 arranged below the porous chuck table 38 by the screws 2 g inserted into each screw hole.

The porous chuck table 8 is rotated around a predetermined rotation shaft 38b substantially parallel to the Z-axis direction by the rotation drive mechanism 42. Similar to the porous chuck table 8, a suction source 46 such as an ejector is connected to the flow path 2d ₁ or the like of the porous chuck table 38 via a solenoid valve 44.

The negative pressure generated in the suction source 46 is transmitted to the holding surface 38a via the flow path 2d ₁ and the like. The workpiece 11 is sucked and held on the holding surface 38a via the protective tape 13 made of resin. The above-mentioned grinding unit 18 is arranged above the holding surface 8a. Since the grinding unit 18 is the same as that in FIG. 3, detailed description thereof will be omitted.

When grinding the back surface 11b side of the workpiece 11, the holding surface 8a sucks and holds the front surface 11a side. Next, with the grinding wheel 24 rotated around the spindle 20, the grinding unit 18 is ground and fed downward at a predetermined speed, and the back surface 11b is ground by pressing the grinding wheel 24b against the back surface 11b.

By the way, in a general grinding apparatus, the holding surface may be ground in order to correct the holding surface of the chuck table (so-called self-grinding). In a general grinding apparatus, the porous plate is made of porous ceramics, and the frame is made of non-porous ceramics.

Since ceramics are usually harder than glass, it is necessary to replace the grinding wheel 24 with a grinding wheel for grinding a holding surface in order to grind a porous plate and a frame made of ceramics.

However, in the porous chuck table 38, both the frame body 2 and the porous plate 4 are made of glass. Therefore, there is an advantage that the holding surface 8a can be ground by the grinding wheel 24 for grinding the workpiece 11 without replacing with the grinding wheel for grinding the holding surface.

In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented as long as they do not deviate from the scope of the object of the present invention.

2: Frame body, 2a: Top surface, 2b: Concave part, 2b ₁ : Bottom surface, 2b ₂ : Side surface, 2c: Bottom surface 2d ₁ , 2d ₂ , 2d ₃ , 2d ₄ : Flow path, 2e: Face-to-face area, 2f: Edge , 2g: Screw 4: Porous plate, 4a: Top surface, 4b: Side surface, 4c: Bottom surface 5: Glass grain, 7: Pore 6: Table body,
8,38: Porous chuck table, 8a, 38a: Holding surface, 38b: Rotating shaft 10: Grinding device 11: Work piece, 11a: Front surface, 11b: Back surface, 13: Protective tape, 15: Modification area 12: Chuck Table, 12a: Holding surface, 12b: Rotating shaft, 14: Suction source 16: Protective sheet 18: Grinding unit, 20: Spindle, 22: Wheel mount 24: Grinding wheel, 24a: Wheel base, 24b: Grinding grindstone 26: Heating furnace, 30: Laser processing device, 32: Electromagnetic valve, 34: Suction source 36: Laser beam irradiation unit 40: Grinding device, 42: Rotary drive mechanism, 44: Electromagnetic valve, 46: Suction source L: Laser beam, P : Focus point

Claims (4)

It is a method of manufacturing a porous chuck table.
A table body preparation step of fitting a porous porous plate made of glass into a recess of a non-porous frame body made of glass to form a table body,
After the table body preparation step, the table body is heated at a temperature equal to or higher than the softening point of the frame body and lower than the melting point to soften the facing region of the concave portion of the frame body facing the outer surface of the porous plate. A method for manufacturing a porous chuck table, which comprises a heating step of deforming the facing region of the concave portion so as to imitate the unevenness of the outer surface of the porous plate to bring it into close contact with the porous plate. The method for manufacturing a porous chuck table according to claim 1, wherein in the heating step, the facing region of the frame body softens before the outer surface of the porous plate facing the facing region. .. After the table body preparation step, a holding surface forming step is further provided in which the upper surface of the porous plate and the upper surface of the frame body are ground to be flush with each other to form a holding surface for sucking and holding the workpiece. The method for manufacturing a porous chuck table according to claim 1 or 2. With a glass and porous porous plate,
A glass, non-porous frame with recesses into which the porous plate is fitted.
The facing region of the concave portion of the frame body facing the outer surface of the porous plate follows the unevenness of the outer surface of the porous plate and is in close contact with the unevenness of the outer surface of the porous plate. A porous chuck table characterized by having an area.

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