JP5261057B2 - Suction board and vacuum suction device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suck a material to be sucked such as a wafer with a relative high planar uniformity on an entire surface of a sucking disk and suppress the bending of the sucking disk itself. <P>SOLUTION: The sucking disk has a plate-like sucking member comprising a first porous material and a support member comprising a compact material and having an abutting face abutting on one major face of the sucking member and a wall for surrounding the side of the sucking member. A groove connected with a vent hole formed at the support member is arranged on the abutting face of the support member. The sucking disk is so configured as to have an auxiliary member being arranged at the inside of the groove, supporting the sucking member, and comprising a second porous material having less air permeability resistance than that of the first porous material. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a suction plate that constitutes a suction surface of a vacuum suction device, and a vacuum suction device including the suction plate.

  Conventionally, in a manufacturing process of a semiconductor or a liquid crystal substrate, a vacuum suction apparatus for fixing and holding a semiconductor wafer, a glass substrate for liquid crystal, or the like as an object to be adsorbed has been used.

  As a vacuum suction device, a porous type has been proposed in which the suction member of the suction disk is made of a porous material. In recent years, with the increase in size of semiconductor wafers and liquid crystal substrates and the sophistication of required processing accuracy, the demand for porous type suction cups has increased. For example, Patent Document 1 discloses an example of such a porous type suction disk.

FIG. 3 is a cross-sectional view of an example of a conventional porous suction cup. FIG. 3 shows a state where the wafer W is sucked and held by the suction disk 100. The suction disk 100 shown in FIG. 3 has a holding base 103 provided with a recess 103a in the center, and a suction member 102 fitted into the recess 103a of the holding base 103. The adsorbing member 102 is made of, for example, a substantially disc-shaped porous ceramic material. On the other hand, the holding base 103 is made of dense ceramic, and a plurality of grooves 105 formed along the outer peripheral shape of the recess 103a are provided on the inner surface of the recess 103a. The plurality of grooves 105 are hollow and communicate with an exhaust hole 107 provided at the center of the holding body 103, and each groove 105 is configured to be sucked from the outside. In the suction plate 100, the cavities of the respective groove portions 105 are exhausted from the outside, and the pores (porous ceramic pores) of the adsorption member 102 function as suction holes. For example, the wafer W) is attracted to the attracting member 102. In the suction disk 100, each groove portion 105 is provided so that the suction force on the upper surface of the suction member 102 is made uniform over the entire upper surface of the suction disk 100. In other words, the suction force is not concentrated in the vicinity of the exhaust hole 107 and is made uniform over the entire upper surface of the suction plate 100. FIG. 3 shows a state in which the suction disk 100 is provided, for example, in a polishing apparatus. In the polishing apparatus, the polishing grindstone 110 is pressed against the upper surface of the wafer W adsorbed on the upper surface of the suction disk 100, and the polishing grindstone 110 is moved while being rotated to polish the surface of the wafer W.
JP-A-10-128634

  In the conventional polishing apparatus shown in FIG. 3, each groove 105 is hollow, and the wafer W is relatively easily bent at a portion corresponding to each groove 105. For this reason, as shown in FIG. 3, when the suction plate 100 is used in a polishing apparatus, for example, the wafer W may bend at a portion corresponding to the groove portion 105 due to the pressing force of the polishing grindstone 110. there were. When polishing is performed in a state in which bending occurs, a polishing amount distribution is generated on the surface of the wafer W, and a polishing mark 120 (surface roughness distribution or unevenness) as shown in FIG. There was also. This application is an invention made in order to solve such a problem.

  In order to solve the above problems, the present invention provides an adsorbing member made of a first porous body, a supporting member having an abutting surface that abuts against one main surface of the adsorbing member, and the abutting of the supporting member. An auxiliary member made of a second porous body that is disposed in a recess provided on the surface and supports the adsorption member, and the support member is provided with an exhaust hole having an opening on the inner surface of the recess. The suction disk is characterized in that the ventilation resistance of the second porous body is smaller than that of the first porous body.

  In addition, it is preferable that the said supporting member is provided with the contact part contact | abutted with the one main surface of the said adsorption member, and the wall part which surrounds the side surface of the said adsorption member.

  Moreover, it is preferable that the said 1st porous body is comprised as a main component the 1st ceramic particle and the glass component which couple | bonds said 1st ceramic particle.

  Further, the second porous body is composed mainly of a second ceramic particle having a larger particle size than the first ceramic particle and a glass component for bonding the second ceramic particles. It is preferable.

The first porous body is composed mainly of first ceramic particles and a glass component that bonds the first ceramic particles, and the second porous body includes the first ceramic particles. compared with the second ceramic particle diameter is large, said the glass component second coupling the ceramic particles to each other is configured as a main component, the second ceramic particles child and the first ceramic particles children Are preferably made of the same material.

Further, the and the adsorption member and the auxiliary member, the first glass component contained in the porous body, and that are joined by glass component contained in the second porous body preferably.

Further, the concave portion, the continuously along the outer peripheral shape of the contact surface, it is preferable that a plurality of the concave portions are disposed concentrically.

  The present invention also provides a vacuum suction apparatus including the suction plate described above and an exhaust pump connected to the exhaust hole of the support member.

  According to the present invention, an object to be adsorbed such as a wafer can be adsorbed from the entire surface of the adsorbing plate with relatively high in-plane uniformity, and the bending of the adsorbing plate itself can be suppressed. By using the vacuum suction device provided with the suction disk of the present invention, for example, a polishing process or the like, even after passing a process in which a relatively high stress is applied to the object to be adsorbed, It can be made relatively small.

  Hereinafter, an embodiment of the present invention will be described in detail. FIG. 1A is a perspective view schematically showing an embodiment of the suction disk of the present invention, and shows a state where a part of the support member 14 and the suction member 12 is cut and deleted. FIG.1 (b) is XX sectional drawing of the suction disk 10 shown to (a). FIG. 1C is a cross-sectional view showing a state in which a wafer W as an object to be adsorbed is placed on the upper surface of the suction disk 10 shown in FIG.

  As shown in FIG. 1A, the suction disk 10 according to this embodiment includes a plate-like suction member 12 made of a first porous body, and a support member made of a dense body that supports the suction member 12. 14. The support member 14 includes a contact surface 14 a that contacts one main surface of the suction member 12, and a wall portion 16 that surrounds the side surface of the suction member 12. A groove portion 18 is provided on the contact surface 14a of the support member 14, and the groove portion 18 is filled with an auxiliary member 24 made of a second porous body having a lower airflow resistance than the first porous body. Has been. Further, the support member 14 is provided with an exhaust hole 22 extending from the contact surface 14a side to the outside (the lower side in FIG. 1), and the exhaust hole 22 extends to the inner surface of the groove portion 18. The inner surface has an open end. The suction disk 10 shown in FIG. 1 is provided in a vacuum suction device that sucks and holds a wafer W, which is a supported member, on its surface, and the exhaust hole 22 is connected to an exhaust pump (not shown).

  The adsorbing member 12 is a substantially disc-shaped member, and is composed mainly of, for example, first ceramic particles made of alundum coarse particles and a glass component for bonding the first ceramic particles. The adsorbing member 12 is made of, for example, a porous ceramic having a porosity of 15 to 40% and an average pore diameter of 0.1 to 0.3 mm. In addition, the value of the porosity in this specification is calculated | required from the observation image by the electron microscope or the optical microscope of the arbitrary cross sections of a measurement object member, for example. Specifically, the porosity value in the present specification can be obtained by cutting out a member to be measured for measuring the porosity into an appropriate size and using a mercury intrusion method.

The porosity can also be measured by the following method. An arbitrary cross section of the measurement target member is observed at a magnification of 20 to 100 times, and an area of the cavity region that can be confirmed from the observation image is obtained for a measurement area range of 5 to 30 mm ² of the observation image, and the area of the cavity region is determined. It is a percentage (%) value divided by the area of the measurement target range. Similarly, the average pore diameter is determined by observing an arbitrary cross section of the measurement target member at a magnification of 20 to 100 times, and the value of the longest diameter of each particle existing in the measurement area range of 5 to 30 mm ² of this observation image. It means the average value. Each value may be obtained by confirming the observation image with the naked eye, or may be obtained by image processing of the taken observation image.

  The support member 14 is made of, for example, a dense ceramic whose main component is aluminum oxide. The support member 14 includes a substantially circular contact surface 14a and a wall portion 16 protruding from the periphery of the contact surface 14a. In other words, the support member 14 has a shape in which a concave portion corresponding to the adsorption member 12 is provided in the central portion of the substantially disk-shaped structure. The adsorbing member 12 is arranged in a state of being fitted in the recess. One main surface of the adsorption member 12 is joined to the contact surface 14 a, and the side surface of the adsorption member 12 is joined to the wall portion 16. The upper surface of the wall portion 16 is substantially flush with the upper surface of the adsorption member 12. At the center position of the support member 14 (center position of the contact surface 14a), an exhaust hole 22 extending from the contact surface 14a side toward the lower side in FIG. 1 is provided. In addition, the shape of the contact surface 14a of the support member 14 is not limited to being substantially circular. The shape of the abutting surface 14a may be an arbitrary shape according to the shape of the object to be adsorbed, and for example, in the suction disk used in the liquid crystal manufacturing apparatus, it may be a substantially square shape.

  The groove portion 18 is provided in a continuous shape along the outer peripheral shape of the contact surface 14. In the suction disk 10 of this embodiment, circular grooves 18a and 18b having the same center as the outer peripheral shape (outer peripheral circle) of the contact surface 14 are formed. Further, the groove portion 18 is provided with a partial groove 19 extending along the diameter direction of the contact surface 14a and extending to the center by connecting the circular grooves 18a and 18b. The exhaust hole 22 extends to the inner surface of the groove 18, and an open end is formed on the inner surface of the groove 18 at the center of the contact surface 14 a.

  The auxiliary member 24 filled in the groove portion 18 is composed mainly of second ceramic particles made of alundum coarse particles and a glass component that bonds the second ceramic particles together. The auxiliary member 24 is made of, for example, a porous ceramic having a porosity of 36 to 60% and an average pore diameter of 0.3 to 1 mm. The auxiliary member 24 is filled in the groove 18 and is joined to the inner wall of the groove 18. For example, the glass component contained in the auxiliary member 24 is melt-bonded to the inner wall surface of the groove 18, and the auxiliary member 24 made of a porous body is bonded to the inner surface of the groove 18. In the suction disk 10 of the present embodiment, the glass component for bonding the first ceramic particles and the glass component for bonding the second ceramic particles are melted and cured, respectively, and the suction member 12 and the auxiliary member 24. Are joined.

In the present embodiment, the second ceramic particles children constituting the first ceramic particles children constituting the adsorbing member 12, an auxiliary member 24 are both made of the same material (Alundum particles). For this reason, in the junction part of the adsorption member 12 and the auxiliary member 24, it is in the state where the grains which consist of the same material and differ in a size were mixed. For this reason, in this embodiment, generation | occurrence | production of a big stress in the boundary of the adsorption | suction member 12 and the auxiliary member 24, advancing of the chemical reaction accompanying the contact of a different substance, etc. are suppressed. In the suction disk 10 of the present embodiment, the suction member 12 and the auxiliary member 24 are well connected, the occurrence of distortion and cracking due to external force is suppressed, and the generation of particles from the suction disk 10 is also suppressed. ing.

The alundum particles are particles mainly composed of alumina and containing, for example, titanium oxide and iron oxide. The alundum particles grow by heating, and the particle size after heating can be controlled by adjusting the heating conditions. First as ceramic particles child and second ceramic particles child, the use of Alundum particles heated at different temperature conditions, respectively, particle made of the same material having different diameters ceramic grains element each (first ceramic particle The adsorbing member 12 and the auxiliary member 24 can be produced, each of which has a child and second ceramic particles as main components. In addition, the Alundum particles, also characteristics such grinding dust of the wafer is less likely to adhere, even in this respect is suitable as the material constituting the suction cup. Further, unlike the spherical shape, the alundum particles have many corners, and the particles have various shapes.

  The suction disk 10 of the present embodiment is used by being mounted on a vacuum suction device for holding a workpiece material such as a wafer, which is provided in various semiconductor manufacturing apparatuses, liquid crystal manufacturing apparatuses, and the like. In such a vacuum suction device, an exhaust pump (not shown) is connected to the exhaust hole 22 of the suction disk 10. When the exhaust pump operates and the air inside the exhaust hole 22 is exhausted, the inside of the groove portion 18 connected to the exhaust hole 22 is also exhausted. That is, in the vacuum suction device, the suction plate 10 sucks the gas contained in the auxiliary member 24 and the suction member 12 which are porous bodies by the operation of an exhaust pump (not shown).

  In the vacuum suction device, the exhaust pump is operated in a state where an object to be adsorbed (for example, a wafer) is placed on the upper surface of the suction plate 10 (upper surface of the suction member 12), and the pores of the suction member 102 (porous ceramic pores). As a suction hole, the wafer W (object to be adsorbed) placed on the upper surface of the adsorption member 12 is adsorbed by the adsorption member 12.

  In the suction disk 10 of the present embodiment, the auxiliary member 24 having a lower ventilation resistance than the suction member 12 is filled in the groove portion 18. That is, in the suction disk 10 of the present embodiment, one main surface (the lower side surface in FIG. 1) of the suction member 12 is supported by the auxiliary member 24 even in the portion of the suction member 12 corresponding to the groove portion 18. For this reason, in the suction disk 10 of this embodiment, the deformation of the suction member 12 in this portion (corresponding portion of the groove portion 18) is suppressed, and consequently, the deflection of the wafer W in the portion corresponding to the groove portion 18 is also suppressed. . The auxiliary member 24 filled in the groove portion 18 has a lower airflow resistance than the suction member 12, and the suction plate 10 has a suction force of the object to be adsorbed by the suction member 12 as in the case where the groove portion 18 is hollow. The in-plane distribution on the upper surface of the film is made relatively small. When a vacuum suction apparatus including the suction disk 10 according to the present embodiment is used and, for example, an object to be adsorbed such as a wafer is adsorbed and supported, bending generated in the wafer or the like is suppressed to be relatively small.

  In the suction disk 10 shown in FIG. 1, the upper surface of the auxiliary member 24 filled in the groove 18 is substantially flush with the contact surface 14a. The suction disk 10 of the present invention is not limited to the upper surface of the auxiliary member 24 being substantially flush with the contact surface 14a. For example, as shown in FIG. While being filled, it may be provided so as to cover the contact surface 14a. Further, the auxiliary member 24 does not need to be filled in the entire groove portion 18, and may be configured to be partially disposed in the groove portion. In the suction disk 10 of the present invention, the arrangement state of the auxiliary members is not particularly limited.

  Next, an example of the manufacturing method of the suction disk 10 will be described.

  First, the support member 14 made of a dense ceramic is prepared. The support member 14 can be manufactured as follows, for example. First, raw material powder composed of 96 to 99.9% by mass of aluminum oxide powder and 0.1 to 4% by mass of sintering aid powder containing each powder of silicon oxide, calcium carbonate, and magnesium oxide was mixed, and polyethylene glycol was mixed. 3 to 8 parts by mass of an organic binder such as is added to 100 parts by mass of the raw material powder and mixed, and water is added to form a slurry. This slurry is spray-dried with a spray dryer, and the resulting granule is filled into a rubber mold and pressed with hydrostatic pressure to produce a molded body. The obtained molded body is processed and cut into a shape close to the shape of the support member to produce a so-called near net molded body. This near-net molded body is fired at 1500 to 1700 ° C. in a firing furnace to produce a sintered body. The sintered body is processed to produce the support member 14.

  Next, a glass paste is applied to the entire inner surface of the support member 14 to a thickness of about 0.2 mm using screen printing, a brush, or the like. At this time, the glass paste is not applied to the inner surface of the exhaust port 22. For example, a glass paste prepared by mixing and kneading a powder made of borosilicate glass having a melting point of 650 to 1000 ° C., a small amount of an organic binder, and a small amount of an organic solvent may be used. The exhaust hole 22 is filled with a thermosetting resin such as an epoxy resin after the step of applying the glass paste, and is thermally cured.

  Next, the raw material of the auxiliary member 24 is filled in the entire groove portion 18 of the support member 14. As a raw material of the auxiliary member 24, what was produced as follows may be used. First, after the alundum is heated to, for example, about 1300 ° C. to grow the grains, only the alundum having a particle diameter of about 0.1 to 0.5 mm is selectively collected using a vibrating sieve. The above-mentioned glass paste is added to and mixed by 7 to 25% by mass (excluding the organic binder and the organic solvent) with respect to 100 parts by mass of the collected alundum, and the raw material of the auxiliary member 24 is produced. Instead of alundum, a mixture of raw materials obtained by selecting substantially spherical glass or ceramic having a diameter in the range of 0.5 to 1 mm may be used as the raw material of the adsorbing member 12.

  Next, the entire inside of the support member 14 is filled with the raw material of the adsorption member 12. At this time, the raw material of the support member 12 is filled until it is substantially flush with the upper surface of the wall portion 16 of the support member 14. As a raw material of the support member 12, what was produced as follows may be used, for example. First, after the alundum is heated to, for example, about 1400 ° C. to grow the grains, only the alundum having a particle diameter of about 0.4 to 1.5 mm is selectively collected using a vibrating sieve. 3 to 8 parts by mass of the above-mentioned glass paste is added to and mixed with 100 parts by mass of the collected alundum to produce a raw material for the adsorbing member 12. In addition, instead of the glass paste, a mixture of raw materials selected from spherical glass and having a diameter in the range of 0.5 to 1 mm is used for the adsorbing member 12 with respect to 100 parts by mass of alundum. It is good also as a raw material.

  Thus, the whole structure filled with the raw material of the adsorbing member 12 is put in a rubber mold and sealed, and pressurized by an isostatic press to obtain an unheated object of the adsorbing board 10. The unheated material is heated at a temperature equal to or higher than the melting point of the glass paste (650 to 1000 ° C.) and then cooled, and the support member 14, the adsorbing member 12, and the auxiliary member 24 are integrally joined with molten glass. During this heating, the thermosetting resin filled in the exhaust hole 22 is melted and evaporated. In this manner, the upper surface of the structure in which the support member 14, the adsorbing member 12, the auxiliary member 24, and the support member 14 are integrally joined by molten glass is smoothly polished by, for example, a surface grinder. The adsorbing member 10 may be produced in this way, for example.

In the production method of the present embodiment, the first ceramic particles child and second ceramic particles child, the use of Alundum particles heated at different temperature conditions, respectively, ceramic of particle size made of the same material are different each composed mainly grains resonator (first ceramic particles child and second ceramic particles), and to produce a suction member 12 and the auxiliary member 24. For this reason, in the junction part of the adsorption member 12 and the auxiliary member 24, it is in the state where the grains which consist of the same material and differ in a size were mixed. In the suction disk 10 manufactured by the manufacturing method of the present embodiment, the generation of large stress, the progress of chemical reaction accompanying the contact of different substances, and the like are suppressed at the boundary between the suction member 12 and the auxiliary member 24. In the suction disk 10 of the present embodiment, the suction member 12 and the auxiliary member 24 are well connected, the occurrence of distortion and cracking due to external force is suppressed, and the generation of particles from the suction disk 10 is also suppressed. ing.

  As mentioned above, although one Embodiment of the suction disk of this invention was described in detail, this invention is not limited to the said embodiment. For example, it is not limited to the groove | channel part which followed the surface on the support member surface, and the recessed part which has a partial opening may be provided. The present invention is not limited to the above-described embodiment, and various improvements and modifications may be made without departing from the scope of the present invention.

(A) is a perspective view which shows an outline about one Embodiment of the suction disk of this invention, and has shown the state which cut | disconnected and deleted some support members and the suction members. (B) is XX sectional drawing of the suction disk shown to (a). (C) is sectional drawing which shows the state which mounted the wafer W which is a to-be-adsorbed object on the upper surface of the suction disk shown to (a). It is a schematic sectional drawing shown about one Embodiment of the suction disk of this invention. It is sectional drawing of an example of the conventional porous type suction disk. It is a perspective view of an example of the wafer ground using the conventional porous type suction disk.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Adsorption board 12 Adsorption member 14 Support member 14a Contact surface 16 Wall part 18 Groove part 18a, 18b Circular groove 19 Partial groove 22 Exhaust hole 24 Auxiliary member 100 Adsorption board 103 Holding base | substrate 103a Concave part 105 Groove part 107 Exhaust hole 110 Grinding stone 120 Polishing mark

Claims (8)

An adsorbing member made of a first porous body;
A support member comprising a contact surface that contacts one main surface of the adsorption member;
An auxiliary member made of a second porous body that is disposed in a recess provided on the contact surface of the support member and supports the adsorption member,
The support member is provided with an exhaust hole having an opening on the inner surface of the recess,
The suction plate according to claim 2, wherein the second porous body has a lower airflow resistance than the first porous body.   The suction plate according to claim 1, wherein the support member includes a contact surface that contacts one main surface of the suction member, and a wall portion that surrounds a side surface of the suction member.   The said 1st porous body is comprised as a main component from the 1st ceramic particle | grain and the glass component which couple | bonds the said 1st ceramic particle | grains. Adsorption board of description. The second porous body is composed mainly of second ceramic particles having a larger particle diameter than the first ceramic particles and a glass component that bonds the second ceramic particles to each other. The suction disk according to claim 3, wherein The first porous body is composed mainly of a first ceramic particle and a glass component that binds the first ceramic particles, and the second porous body is compared with the first ceramic particle. Second ceramic particles having a large particle size, and a glass component that bonds the second ceramic particles to each other.
Wherein the first ceramic particles child and the second ceramic particles children, according to claim 1 or 2 suction cup according to characterized in that it consists of the same material. Wherein the said auxiliary member and the suction member, the first glass component contained in the porous body, and according to claim 5, characterized in that it is joined by a glass component contained in the second porous body Suction board. The concave portion is continuous along the outer peripheral shape of the abutment surface,
Sucker as claimed in claim 1 in which a plurality of the concave portion is characterized by being arranged concentrically. The suction disk according to any one of claims 1 to 7,
An exhaust pump connected to the exhaust hole of the support member;
A vacuum suction apparatus comprising:

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