JP2020021799A - Vacuum chuck table - Google Patents

Abstract

To provide a vacuum chuck table capable of uniformly diffusing light without using a planar light emitting device.SOLUTION: A vacuum chuck table 10 includes an adsorption member 11 that adsorbs an object W, an LED 12 that irradiates the object W with light through the adsorption member 11, and a base 13 that supports the adsorption member 11. The adsorption member 11 is made of a porous silica material, and has a first porous body 11A and a second porous body 11B having different average particle diameters and average pore sizes. The first porous body 11A has a larger average particle diameter and a larger average pore diameter than the second porous body 11B, and the second porous body 11B is provided so as to correspond to the LED 12 such that light from the LED 12 is directly incident.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vacuum-attached chuck table that supports an object by adsorbing air onto an adsorption member by suction of air.

  Conventionally, an object is adsorbed on an adsorbing member by suction of air, and a shadow of the object is formed by irradiating light from the back surface.The outline of the object is confirmed from the shadow, and dimensions and defective products are inspected. There is known a vacuum chuck table for processing. For example, Patent Literature 1 discloses an adsorption member 4 made of a porous material, a planar light emitting device 2 for supplying planar light to the back surface of the adsorption member 4, and an adsorption member 4 and a planar light emitting device 2 A surface light-emitting chuck table 1 having an air passage member 3 disposed therebetween is described (see FIG. 3). In the surface light-emitting chuck table 1, the use of the surface light-emitting device 2 enables uniform irradiation of an object. The planar light-emitting device 2 includes a casing 7 in which a light reflecting member 14 is provided on the bottom surface and the peripheral surface of the concave portion 13 and a radiation-side reflecting member 8. While being repeatedly reflected by the light reflection member 14 and the radiation side reflection member 8 of the concave portion 13 of the casing 7, the radiation is radiated upward from the opening of the radiation side reflection member 8 so that uniform light can be irradiated in a planar manner. Has become.

JP-A-2006-9752

  However, in the surface-emitting chuck table described in Patent Literature 1, since planar light is supplied to the back surface of the suction member using the planar light-emitting device, the number of parts increases, the weight increases, and the cost increases. There was a problem that becomes high.

  The present invention has been made based on such a problem, and has as its object to provide a vacuum chuck table capable of uniformly diffusing light without using a planar light emitting device.

  The vacuum chuck table of the present invention includes a plate-shaped suction member made of porous silica and adsorbing an object on the surface, an LED (Light Emitting Diode) for irradiating the object with light through the adsorption member, and a back surface of the adsorption member. Provided on the side, and a suction unit for sucking air through the suction member, the suction member having a first porous body portion and a second porous body portion having different average particle diameters and average pore diameters, The first porous body has a larger average particle diameter and an average pore diameter than the second porous body, and the second porous body is provided at a position corresponding to the LED so that light from the LED is directly incident. The light incident on the second porous body is diffused in the second porous body, and at least a part of the light is transmitted through the first porous body.

  According to the vacuum chuck table of the present invention, the adsorption member is provided with the first porous body and the second porous body having different average particle diameters and average pore diameters, and the first porous body is provided with the second porous body. Since the average particle diameter and the average pore diameter are larger than those of the first porous body, the first porous body can have a higher light transmittance than the second porous body, and the second porous body has the first porous body. The light diffusivity can be increased as compared with. Further, the second porous body is provided at a position corresponding to the LED so that the light from the LED is directly incident, so that the light from the LED is incident on the second porous body having a high light diffusion property. Then, the light is diffused in the second porous body, and at least a part thereof can be transmitted through the first porous body having high light transmittance. Therefore, the light of the LED can be diffused uniformly in the adsorption member, and the object can be irradiated with uniform light. It is also possible to irradiate the target object with uniform light even on the porous body portion on the column supporting the porous body portion. Therefore, a planar light emitting device becomes unnecessary, and the weight of the device can be reduced, and the cost can be significantly reduced.

  Further, by arranging the first porous body portion and the second porous body portion in direct contact, light can be more easily diffused.

  In addition, the average particle diameter of the silica particles forming the first porous body part is 50 μm or more and 100 μm or less, the average pore diameter is 10 μm or more and 20 μm or less, and the average particle diameter of the silica particles forming the second porous body part is 15 μm or more. If the average pore diameter is less than 50 μm, the average pore diameter is 5 μm or more and less than 10 μm, and the average particle diameter of the first porous body is 10 μm or more larger than that of the second porous body, higher effects can be obtained.

  Furthermore, if an inclined surface is formed on the side surface of the second porous body portion and an inclined surface is formed on the first porous body portion corresponding to the inclined surface of the second porous body portion, the second porous body portion and the second porous body portion are formed. The boundary with one porous body can be an inclined surface. Therefore, it is possible to suppress sudden darkening at the boundary surface or excessive light emission at the boundary portion. In addition, uniform light can be applied to the target object also on the porous body portion on the column supporting the porous body portion.

FIG. 1A is a cross-sectional view illustrating a configuration of a vacuum chuck table according to a first embodiment of the present invention. (2) is a drawing showing the shape and arrangement of the second porous body of the vacuum chuck table shown in (1) as viewed from below. It is a sectional view showing the composition of the vacuum chuck table concerning a 2nd embodiment of the present invention. It is an exploded sectional view showing the composition of the conventional surface emitting chuck table.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment)
FIG. 1A shows a configuration of a vacuum chuck table 10 according to the first embodiment. The vacuum chuck table 10 suctions and supports an object W by suction of air. For example, an adsorption member 11 that adsorbs the object W on a surface thereof, and light is applied to the object M through the adsorption member 11. An LED 12 for irradiation and a base 13 for supporting the suction member 11 are provided. The target object W is, for example, a semiconductor wafer. FIG. 1B shows the second porous body corresponding to the first embodiment viewed from below. Although A corresponds to FIG. 1A, shapes and arrangements such as B and C may be used. In FIG. 1B, the second porous body is shown with a satin finish for easy understanding.

  The suction member 11 has, for example, a plate shape such as a disk shape, and has a flat suction surface for sucking the target object W. The size of the suction member 11 is, for example, about 250 mm in diameter and about 10 mm in thickness. The adsorbing member 11 is made of a porous silica material having air permeability and translucency, and has a first porous body portion 11A and a second porous body portion 11B having different average particle diameters and average pore diameters. . 11 A of 1st porous body parts are comprised so that an average particle diameter and an average pore diameter may become larger than 2nd porous body part 11B. As a result, the first porous body 11A has a characteristic that the light transmittance is higher than that of the second porous body 11B, and the second porous body 11B has a property of being higher than that of the first porous body 11A. It has the property of high light diffusion.

  The second porous body portion 11B is provided at a position corresponding to the LED 12 so that light from the LED 12 is directly incident. This is because the highly directional light radiated from the LED 12 is made incident on the second porous body 11B having a high light diffusion property and diffused by the second porous body 11B to improve the uniformity of light in the plane direction. In addition, by configuring a portion apart from the LED 12 other than the second porous body 11B from the LED 12 by the first porous body 11A having a high light transmittance, a part of the light diffused by the second porous body 11B is reduced. Since the light can easily pass through the first porous body portion 11A, the uniformity of light in the plane direction can be further improved.

  The average particle size of the silica particles forming the first porous body portion 11A is 50 μm or more and 100 μm or less, the average pore size is 10 μm or more and 20 μm or less, and the average particle size of the silica particles forming the second porous body portion 11B is 15 μm or more. Preferably, the average pore diameter is less than 50 μm, the average pore diameter is 5 μm or more and less than 10 μm, and the average particle diameter of the first porous body portion 11A is 10 μm or more larger than that of the second porous body portion 11B. This is because higher effects can be obtained within this range. The average particle diameter is a value derived by a laser diffraction / scattering method.

  The first porous body portion 11A and the second porous body portion 11B are preferably in direct contact, and more preferably joined. This is because the light can easily enter the first porous body portion 11A from the second porous body portion 11B, and the light can be more easily diffused. The side surface of the second porous body portion 11B may be a surface perpendicular to the front surface and the back surface, but the side surface of the second porous body portion 11B is formed with a surface inclined with respect to the front surface and the back surface. Is preferred. In addition, it is preferable that a surface that is inclined corresponding to the inclined surface of the second porous body 11B is formed in the first porous body 11A. By making the boundary between the second porous body portion 11B and the first porous body portion 11A an inclined surface, it is possible to prevent the boundary portion from being suddenly darkened or the boundary portion from being too bright. This is because light can be made uniform over a wide range.

  A part of the second porous body part 11B may be, for example, exposed to the surface and constitute a part of the suction surface. The second porous body portion 11B may have, for example, a columnar shape or a dome shape, but preferably has a truncated conical shape having a large area on the back surface side.

  The suction member 11 is fixedly supported on the inner peripheral surface of the annular support frame 14. The support frame 14 is made of a material that does not bend, for example, stainless steel or aluminum. It is preferable that a holding member 15 for suppressing bending of the suction member 11 is provided on the back surface side of the suction member 11. The holding member 15 is preferably arranged in contact with the back surface of the suction member 11, and is preferably made of transparent glass or plastic. The holding member 15 is provided with, for example, a groove-shaped or hole-shaped ventilation hole 15A for passing air.

  The base 13 is provided, for example, on the back side of the suction member 11, and has a hollow suction part 13 </ b> A for sucking air through the suction member 11 inside. The base 13 is made of, for example, stainless steel or aluminum. The base 13 has, for example, a disk-shaped substrate 13B and an annular base frame 13C, and by joining these with screws 13D, a concave suction portion 13A is formed. The suction unit 13A is connected to a suction device (not shown) via, for example, a suction port 13E. A plurality of LEDs 12 are provided at the bottom of the suction portion 13A, and a plurality of second porous body portions 11B are individually arranged at positions facing the respective LEDs 12. For example, the number of LEDs is appropriately about 4 to 12.

  It is preferable that a support 16 supporting the holding member 15 and the suction member 11 is provided at a position corresponding to the center of the suction member 11 at the center of the suction part 13A. This is for suppressing the bending of the suction member 11. The support 16 is made of, for example, quartz glass or aluminum. It is preferable that a slope corresponding to the first porous body or the second porous body exists in a portion corresponding to the support 16 of the suction member 11 as much as possible. This is because by increasing the light transmittance, the provision of the columns 16 prevents the portions corresponding to the columns 16 from being darkened. The support 16 is provided on the substrate 13B by, for example, a screw 16A.

  The vacuum chuck table 10 can be manufactured, for example, as follows. First, for example, spherical silica forming the first porous body portion 11A is classified so as to have a desired average particle size, mixed with a binder, and cast into a mold having a desired shape. At a predetermined temperature for about 3 hours to 12 hours to cause gelation. Next, for example, the gel is released and calcined by maintaining the gel at a predetermined temperature of about 1300 ° C. to 1350 ° C. for about 10 hours to 15 hours to form the first porous body portion 11A.

  Subsequently, in the space portion of the obtained first porous body portion 11A, spherical silica forming the second porous body portion 11B is classified so as to have an intended average particle size, and a slurry mixed with a binder is cast, It is fired again by holding it at a predetermined temperature of about 1250 ° C. to 1300 ° C. for about 10 hours to 15 hours. Thereby, the adsorption member 11 in which the second porous body portion 11B is formed at a predetermined position is obtained. Next, for example, the support frame 14 and the holding member 15 are prepared, the holding member 15 is provided on the back surface of the suction member 11, and fixed to the inner peripheral surface of the support frame 14.

  After that, for example, the LED 12 is disposed on the substrate 13B, and the support 16 is fixed to the center of the substrate 13B with the screw 16. Further, a base frame 13C and a support frame 14 provided with the suction member 11 and the holding member 15 are sequentially laminated on the substrate 13B, and fixed with screws 13D. Thereby, the vacuum chuck table 10 is obtained.

  In addition, the manufacturing experiment of the adsorption member 11 which joined the 1st porous body part 11A and the 2nd porous body part 11B was performed as follows. First, spherical silica is wet-classified, adjusted to have an average particle diameter of 75 μm, and dried, and then the raw material powder and the binder are mixed at a mass ratio of 12: 5 to obtain a slurry mixture. Was dispersed using an ultrasonic cleaner. As the binder, tetramethyl orthosilicate (TEOS), ultrapure water, 0.1 mol / L hydrochloric acid, and propylene glycol were used. TEOS: ultrapure water: 0.1 mol / L hydrochloric acid: propylene glycol After stirring for 2.5 hours with a stirrer at a mass ratio of 12: 9: 1: 3, a silica sol adjusted to pH 4.5 to 5.0 with 0.1 mol / L ammonia was used.

  Next, the prepared slurry is cast into a ring-shaped mold having an outer diameter of 75 mm and an inner diameter of 28 mm, and is left at 50 ° C. for 3 hours to be gelled. Then, the gel is released, and the gel is held at 1350 ° C. for 12 hours and fired. Thus, a first porous body portion 11A was obtained. Subsequently, a slurry in which spherical silica having an average particle diameter of 20 μm and a binder were mixed in the same manner as in the first porous body portion 11A was cast into the inside of the obtained first porous body portion 11A, and the slurry was stirred at 1300 ° C. for 12 hours. By holding, it was fired again. The same binder as that of the first porous body portion 11A was used. Thus, the adsorption member 11 in which the second porous body portion 11B was disposed inside the first porous body portion 11A was obtained. In the obtained adsorption member 11, the first porous body portion 11A and the second porous body portion 11B were joined and integrated, and good characteristics were obtained.

  The vacuum chuck table 10 operates, for example, as follows. First, a suction device (not shown) is connected to the suction unit 13 </ b> A, and suctions air through the suction member 11 to suck and support the target object W on the surface of the suction member 11. Light is emitted from the back side of the object W by the LED 12. The light emitted from the LED 12 passes through the holding member 15, enters the second porous body 11B of the adsorbing member 11, and is diffused by the second porous body 11B. Part of the light diffused by the second porous body part 11B is transmitted through the first porous body part 11A and is irradiated on the object W, and the other part is transmitted through the second porous body part 11B and becomes an object. The object W is irradiated.

  As described above, according to the present embodiment, the adsorption member 11 is provided with the first porous body portion 11A and the second porous body portion 11B having different uniform particle diameters and average pore diameters. Since the average particle diameter and the average pore diameter are larger than the second porous body portion 11B, the first porous body portion 11A can have a higher light transmittance than the second porous body portion 11B, The body portion 11B can have higher light diffusivity than the first porous body portion 11A. Further, the second porous body portion 11B is provided at a position corresponding to the LED 12 so that the light from the LED 12 is directly incident on the second porous body portion 11B. And is diffused in the second porous body portion 11B, and a part of the light can be transmitted through the first porous body portion 11A having a high light transmittance. Therefore, the light of the LED 12 can be diffused uniformly in the adsorption member, and the object W can be irradiated with uniform light. Therefore, a planar light emitting device becomes unnecessary, and the weight of the device can be reduced, and the cost can be significantly reduced.

  Furthermore, if the first porous body portion 11A and the second porous body portion 11B are arranged in direct contact, light can be more easily diffused.

  In addition, the average particle size of the silica particles forming the first porous body portion 11A is 50 μm or more and 100 μm or less, the average pore diameter is 10 μm or more and 20 μm or less, and the average particle size of the silica particles forming the second porous body portion 11B is Higher effects can be obtained if the average pore diameter is 15 μm or more and less than 50 μm, the average pore diameter is 5 μm or more and less than 10 μm, and the average particle size of the first porous body portion 11A is 10 μm or more than that of the second porous body portion 11B. .

  Furthermore, if an inclined surface is formed on the side surface of the second porous body portion 11B and an inclined surface is formed on the first porous body portion 11A corresponding to the inclined surface of the second porous body portion 11B, the second porous body The boundary between the portion 11B and the first porous body 11A can be an inclined surface. Therefore, it is possible to suppress sudden darkening at the boundary surface or excessive light emission at the boundary portion.

  The first porous body 11A and the second porous body 11B may be separately formed and combined, and then integrated at the time of firing, or may be separately fired, bonded or fired, and integrated. .

(Second embodiment)
FIG. 2 shows a configuration of a vacuum chuck table 20 according to the second embodiment. The vacuum chuck table 20 according to the first embodiment is the same as the vacuum chuck table 10 according to the first embodiment except that the structures of the first porous body portion 21A and the second porous body portion 21B and the location of the LED 22 are different. It has the same configuration as. Therefore, the same components are denoted by the same reference numerals, and the corresponding components are denoted by reference numerals with the tens place changed to “2”, and detailed description thereof will be omitted.

  In the first embodiment, the case where the LEDs 12 are disposed on the bottom of the suction unit 13A, that is, on the substrate 13B has been described. However, in the present embodiment, the plurality of LEDs 22 are embedded in the suction member 21. It is arranged. For example, each LED 22 is embedded on the back side of the adsorption member 21. A plurality of second porous body portions 21B are provided, for example, so as to individually surround each LED 22. Specifically, the second porous body portion 21B individually covers the surface side and the side surface of each LED 22. The first porous body portion 21A is provided so as to cover, for example, the front surface and side surfaces of the second porous body portion 21B. It is preferable that an inclined surface inclined with respect to the front surface and the back surface is formed on the side surface of each second porous body portion 21B as in the first embodiment. It is preferable that an inclined surface that is inclined corresponding to the inclined surface of the second porous body portion 11B is formed. Others are the same as the first embodiment, and can be manufactured in the same manner.

  In this vacuum chuck table, light emitted from the LED 22 enters the second porous body portion 21B of the suction member 21 without passing through the holding member 15, is diffused by the second porous body portion 21B, and is diffused by the first porous body 21B. The target object W is irradiated through the portion 21A. Others operate in the same manner as the first embodiment. Further, it has the same effect as the first embodiment, and furthermore, since the LED 22 is embedded in the adsorbing member 21, the height of the device can be reduced and the device can be downsized. Further, in this embodiment, since the light of the LED 22 does not pass through the holding member 15, there is an advantage that the light is hardly attenuated, and since the light is above the support 16, the support 16 cannot be shadowed.

  As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the above embodiment, and can be variously modified. For example, in the above-described embodiment, each component has been specifically described. However, not all components may be provided, and other components may be provided.

  For example, the support frame 14, the base frame 13C, the support 16 and the substrate 13B do not need to be individual components, and are integrated with other components, for example, by integrating the support frame 14 and the base frame 13C. May be.

  For example, in the first embodiment, a part of the second porous body portion 11B may be exposed to the surface to constitute a part of the suction surface, or as in the second embodiment. Alternatively, the surface side may be covered by the first porous body portion 11A without exposing the second porous body portion 11B to the surface. Further, also in the second embodiment, a part of the second porous body portion 21B may be exposed on the surface to constitute a part of the suction surface.

  The present invention can be used as a device for supporting an object such as a semiconductor wafer by suction by suction of air.

  10, 20: vacuum chuck table, 11, 21, suction member, 11A, 21A: first porous body portion, 11B, 21B: second porous body portion, 12, 22, ... LED, 13: base, 13A: suction portion , 13B: substrate, 13C: base frame, 13D: screw, 13E: suction port, 14: support frame, 15: holding member, 15A: vent, 16: support, 16A: screw, W: target object

Claims (6)

A plate-shaped adsorption member made of porous silica and adsorbing an object on its surface,
An LED that irradiates the object with light through the suction member,
A suction unit provided on the back surface side of the suction member, for suctioning air through the suction member,
The adsorption member has a first porous body portion and a second porous body portion having different average particle diameters and average pore diameters,
The first porous body has a larger average particle diameter and a larger average pore diameter than the second porous body,
The second porous body portion is provided at a position corresponding to the LED such that light from the LED is directly incident thereon,
The vacuum chuck table, wherein the light incident on the second porous body is diffused in the second porous body, and at least a part of the light is transmitted through the first porous body.   The vacuum chuck table according to claim 1, wherein the first porous body portion and the second porous body portion are in direct contact with each other.   The average particle diameter of the silica particles forming the first porous body part is 50 μm or more and 100 μm or less, the average pore diameter is 10 μm or more and 20 μm or less, and the average particle diameter of the silica particles forming the second porous body part is 15 μm or more. The average pore diameter is less than 50 μm, the average pore diameter is 5 μm or more and less than 10 μm, and the average particle diameter of the first porous body part is 10 μm or more than the second porous body part. 2. The vacuum chuck table according to 2.   An inclined surface is formed on a side surface of the second porous body portion, and an inclined surface is formed on the first porous body portion corresponding to the inclined surface of the second porous body portion. The vacuum chuck table according to any one of claims 1 to 3, wherein:   The vacuum chuck table according to any one of claims 1 to 4, wherein a part of the second porous body portion is exposed on a surface.   The vacuum chuck table according to any one of claims 1 to 5, wherein the second porous body has a truncated cone shape.

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