JP2009111293A - Vacuum suction apparatus and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin and light-weight vacuum suction apparatus for carrying, which is superior suction performance. <P>SOLUTION: The vacuum suction apparatus for carrying a substrate comprises a mounting part composed of a ceramics porous body, having a mounting surface for mounting the substrate, a roughly concave frame part composed of dense ceramics surrounding the mounting part and a support part for supporting the frame part. The vacuum suction apparatus is provided with a suction hole which directly communicates with substantially the center of the mounting part and is provided on the concave part bottom surface of the frame part; a first suction groove communicating with the mounting part via the suction hole and provided on the bonding surface of the frame part or the support part; and the mounting part and the frame part are directly bonded without a gap. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a vacuum suction apparatus that holds, for example, a semiconductor wafer or a glass substrate by suction.

Conventionally, when a semiconductor wafer is transported, processed, or inspected, for example, in the manufacturing process of a semiconductor device, a vacuum suction device using a vacuum pressure has been used. A vacuum adsorption apparatus in which a porous body is formed has been used. For example, the mounting portion made of a porous body is bonded to the support portion with an adhesive such as resin or glass, and vacuum suction is performed from the lower suction hole, so that the semiconductor wafer is placed on the mounting surface of the mounting portion. The thing which adsorb | sucks the whole surface is proposed (for example, patent document 1).
Japanese Patent Laying-Open No. 2005-50855

In particular, in recent years, semiconductor wafers have become thinner, and warping and cracking are likely to occur, making it difficult to handle. In addition, with the increase in process accuracy and wafer diameter, single-wafer processing is widely performed, and a vacuum adsorption device using a porous body that can adsorb the entire wafer surface is used. ing.

In transferring the wafer, the suction device is preferably lightweight because the wafer is sucked and moved by the suction device attached to the tip of the arm. Further, in order to take out the wafers one by one from the case in which the wafers are stored in multiple stages, it is desirable that the suction device itself be thin.

Here, in order to manufacture a thin and lightweight adsorption device, the porous body itself needs to be processed into a thin shape, but since the porous body is fragile, it is difficult to process the thin shape, and even if it can be processed, the subsequent handling In addition, there is a problem that cracks and chips are likely to occur during joining.

In addition, since the bonding material easily penetrates into the porous body, it is difficult to bond the porous body without unevenness, and there are many problems that the mounting portion is detached.

Furthermore, in the thin suction device, the arrangement of the suction holes and suction grooves is restricted due to the shape, so it is difficult to form these, and the wafers that are sucked are wrinkled or damaged without obtaining proper suction performance. There was a problem to do.

The present invention has been found in view of these problems, and provides a vacuum suction device for conveyance that is thin and light and has excellent suction performance.

In order to solve the above-mentioned problems, the present invention provides a mounting portion made of a porous ceramic body having a mounting surface on which a substrate is mounted, and a frame portion made of a substantially concave dense ceramic surrounding the mounting portion. A vacuum suction device for transporting a substrate, comprising: a support portion that supports the frame portion; and a suction hole provided in a bottom surface of the concave portion of the frame portion that communicates directly with the substantially center of the mounting portion. And the first suction groove provided on the joint surface of the frame part or the support part, and the gap between the placement part and the frame part. There is provided a vacuum suction device characterized by being directly joined without any problem.

By adopting such a configuration, it is possible to obtain an adsorption device that is thin, has no cracks or chips in the porous body, and does not come off the porous body. Furthermore, according to the present invention, even if it is a thin shape, it can be sucked from the center portion, so that the problem that the wafer is wrinkled or broken is also solved. In addition, by adopting a structure in which the mounting portion and the frame portion are directly joined without an adhesive layer, a gap or adhesion due to penetration of an adhesive material into a porous body such as a conventional vacuum suction device is achieved. Since the defect does not occur, the problem that the mounting portion is detached is solved.

In the vacuum suction device of the present invention, the placement portion has a thickness of 2 mm or less, and the total thickness of the vacuum suction device including the placement portion is 5 mm or less. Further, the first suction groove communicates with both the suction hole and the mounting portion, and the first suction groove has a second suction groove provided on the bottom surface of the concave portion of the frame portion that communicates with the suction hole. Features. Thus, even if it is very thin, a vacuum suction device that can suck the entire surface of the substrate and does not cause damage to the wafer is provided.

The reason why the thickness of the mounting portion is 2 mm or less and the total thickness of the vacuum suction device is 5 mm or less is that a vacuum suction device larger than this range is not suitable for transport where thinness is required, and as in the present invention. This is because a simple vacuum suction device configuration is not required. Here, the thickness of the placement portion is preferably 0.5 mm or more. This can be provided as the thickness of the mounting portion that can be produced and used without damage from the processing load at the time of processing the mounting portion and the vacuum pressure at the time of wafer adsorption. Accordingly, considering the workability of ceramics and the like, the total thickness of the vacuum suction device is preferably 2 mm or more. As thickness of a frame part and a support part, producing in the range of 1-2.5 mm is preferable.

The material of the support part is a metal matrix composite material (MMC) made of ceramics as a reinforcing material or dense ceramics. By joining the support portions, the first suction groove can be easily formed even with a thin vacuum suction device. Further, if a metal matrix composite material made of ceramics as a reinforcing material is used as the material of the support portion, the toughness can be greatly increased, and a vacuum suction device that is not easily damaged even if it is thin can be obtained.

The vacuum suction device of the present invention includes a step of feeding a mixture of ceramic powder and a raw material of a ceramic porous body containing a binder into a substantially concave frame portion, molding the molded body, and bonding the molded body together with the frame portion The ceramic porous body is obtained by heating to a temperature higher than the temperature at which the material melts, the step of directly joining the ceramic porous body and the frame portion without gaps by the binder, and the frame portion and the support portion are joined. It is obtained by a manufacturing method including a step and a step of polishing the frame portion and the ceramic porous body together to form a placement portion. According to such a manufacturing method, the ceramic porous body of the frame portion and the mounting portion can be directly joined without a gap, and the processing step of the ceramic porous body that easily causes problems such as cracking and chipping is avoided. In addition, since the joining of the frame portion and the ceramic porous body can be performed simultaneously with the firing of the ceramic porous body, the process can be simplified.

As described above, according to the present invention, it is possible to provide a vacuum suction device that solves problems such as cracking, chipping, and detachment of the mounting portion, is thin and light, and has excellent suction performance.

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

FIG. 1 is a schematic view of a disk-shaped vacuum suction device 10. Fig.1 (a) is the top view seen from the mounting surface side of a vacuum suction apparatus, FIG.1 (b) is an arrow line view of the AA cross section in Fig.1 (a), and FIG. c) is an arrow view seen from the side A in FIG. The vacuum suction device 10 includes a disc-shaped mounting portion 1, a substantially concave frame portion 2 provided so as to surround other than the mounting surface 1 a of the mounting portion 1, the mounting portion 1 and the frame portion 2. And a support portion 7 for supporting. The wafer is placed so as to cover the placement unit 1, and the pores of the placement unit 1 are vacuum-sucked through the suction hole 4, the first suction groove 5, and the second suction groove 6 to place the wafer. Adsorbed and held on the surface 1a. As can be seen from FIG. 1, the first suction groove 5 communicates with the placement portion 1 and the second suction groove 6 through the suction hole 4. Moreover, the frame part and the support part are provided with handle parts 3 and 13 (FIG. 3) for connecting to the arm.

The open porosity of the mounting portion 1 is preferably 20% or more and 50% or less, and the average pore diameter is preferably 1 μm or more and 100 μm or less. The reason why the open porosity of the mounting portion 1 is in such a range is that if it is within the above range, the pressure loss becomes large and it becomes difficult to obtain sufficient adsorption force, or sufficient mechanical strength is obtained. This is because it cannot be obtained or the flatness of the mounting surface 1a is not lowered. In addition, the average pore diameter within the above range is that if the average pore diameter is less than 1 μm, the pressure loss may increase and the adsorptive power may be weakened. Conversely, if the average pore diameter exceeds 100 μm, the surface accuracy of the mounting surface 1a may be deteriorated. Because there is.

The mounting portion 1 is made of a ceramic porous body. Specifically, it has a porous structure composed of predetermined ceramic powder and binder glass and having open pores communicating therewith. For the ceramic powder, for example, alumina, zirconia, silicon carbide, silicon nitride or the like can be used.

It does not specifically limit as glass of the binder used for the mounting part 1, The glassy binder etc. which are used for a vitrified grindstone can be used. Specifically, for example, an aluminosilicate glass having a softening point in the vicinity of 1000 ° C. or a borosilicate glass having a softening point of 900 ° C. or less can be used.

FIG. 2 shows the structure of the frame portion. Fig.2 (a) is a top view seen from the mounting surface side (B side in FIG.2 (b)), FIG.2 (b) is an arrow directional view of the BB cross section in Fig.2 (a). FIG. 2 (c) is a plan view seen from the side of the joint surface with the support portion (c side in FIG. 2 (b)). On the bottom surface of the concave part in which the mounting part of the frame part is accommodated, there is a suction hole 4 in the approximate center, and a second suction groove 6 is formed which communicates directly therewith. A first suction groove 5 that is in direct communication with the suction hole 4 is provided on the side of the joint surface with the support portion.

The reason why the suction hole 4 is provided at substantially the center of the bottom surface of the concave portion is to prevent the wafer from being wrinkled or damaged by sucking the wafer from the substantially center. This is because when the suction hole is formed at a position deviated from the center of the bottom surface of the concave portion, the expression of the adsorption force is delayed at the position farthest from the suction hole, and the adsorption force is biased. In FIG. 2, the second suction groove is provided radially, but the shape of the second suction groove is not limited to this, and various shapes such as a ring or a combination of a ring and a radial are adopted. it can. Further, when a uniform suction force is generated only by the suction holes, the second suction groove may not be provided. The diameter of the suction hole and the width of the second suction groove have sufficient suction power so that the mounting part can be manufactured and used without damage due to the processing load during processing of the mounting part and the vacuum pressure during wafer suction. It is desirable that it is as small as possible.

The material of the frame part 2 is not particularly limited, and a dense ceramic such as alumina, zirconia, silicon carbide, silicon nitride or the like is used. However, from the viewpoint of thermal expansion, it is preferable to use the same ceramic as the ceramic powder of the mounting portion.

In the example of FIG. 2, the first suction groove 5 is formed on the joint surface side of the frame portion. However, as shown in FIG. 4, the first suction groove 15 may be formed on the joint surface side of the support portion 7. . If the configuration of the first suction groove as shown in FIG. 2 or FIG. 4 is used, the suction hole formed in the approximate center of the frame portion and a vacuum source such as a vacuum pump without increasing the thickness of the vacuum suction device Can be connected.

The material of the support part 7 is a metal matrix composite material (MMC) using ceramics as a reinforcing material or a dense ceramic. By adopting a configuration in which the support portions are joined as described above, the first suction groove can be easily formed even with a thin vacuum suction device. In particular, if a metal matrix composite material made of ceramics as a reinforcing material is used as the material of the support portion, the toughness can be significantly increased, and a vacuum suction device that is not easily damaged even if it is thin can be obtained. As the dense ceramic, ceramics such as alumina, zirconia, silicon carbide, and silicon nitride can be used.

Next, the manufacturing method of the vacuum suction apparatus 10 of this invention is demonstrated. First, water or alcohol is added to and mixed with ceramic powder, which is a raw material of the porous ceramic body that forms the mounting portion 1, and glass powder, which is a binder, to prepare a slurry. For mixing the raw materials, a known method such as a ball mill or a mixer can be applied. Here, the amount of water or alcohol is not particularly limited, but the amount of water or alcohol added is adjusted so that desired fluidity can be obtained in consideration of the particle size of the ceramic powder and the amount of glass powder added. The amount of the ceramic powder and the glass powder is adjusted in consideration of the target open porosity, the particle size of the ceramic powder, the firing temperature, the glass viscosity, and the like. It is desirable to add in the range of 30 parts by mass.

Next, the mounting portion of the ceramic frame portion 2 produced by a known molding method such as CIP molding or cast molding, a known firing method such as electric furnace firing or hot press, and a known grinding method using a diamond grindstone or the like The slurry is filled in the concave mold portion where the is formed. At this time, it is preferable to apply vacuum defoaming for removing coarse bubbles in the slurry and vibration for enhancing the filling as necessary. Further, the second suction groove 6 and the suction hole 4 are closed with a burned-out member such as wax or resin before pouring the mixture serving as the placement portion. The suction hole is essential for vacuum suction, but the suction groove can be eliminated if necessary. That is, as long as a sufficient and uniform vacuum suction force can be obtained, only the suction holes may be used.

After the molded body filled and molded in the concave part of the frame part is sufficiently dried, the whole frame part is fired at a temperature at which the glass melts (at least a temperature equal to or higher than the softening point). At this time, if the firing temperature is lower than the softening point of the glass, the glass does not melt and the ceramic powder cannot be bonded. Conversely, if the firing temperature is too high, deformation or shrinkage occurs. Thus, it is desirable to fire at as low a temperature as possible. In this way, the mounting part raw material is directly filled into the concave part of the frame part, molded, and baked as it is, so that the structure is directly joined without an adhesive layer between the mounting part and the frame part. It can be. In the vacuum suction device of the present invention, the adhesive layer is not formed, and a gap or poor adhesion due to penetration of the adhesive layer into the pores as in the conventional vacuum suction device does not occur, so that the problem that the mounting portion is detached is solved.

Next, the frame part in which the ceramic porous body used as a mounting part was formed in the concave mold part, and a support part are joined. For the bonding, a known method such as glass bonding, bonding using an epoxy or silicon adhesive, or brazing can be employed. If joining is accompanied by heat treatment, joining may be performed simultaneously with firing of the mounting portion. When the support portion is a dense ceramic, glass bonding is preferable, and when the support is a metal-based composite material using ceramic as a reinforcing material, bonding using an adhesive is preferable.

The mounting surface is formed by polishing both the frame portion and the ceramic porous body formed on the concave portion. According to this method, the ceramic porous body, which is weak in strength and easily cracked or chipped, can be processed into a thin mounting portion, and the ceramic porous body is directly joined to the frame portion without any gaps. The accuracy is also excellent, and the surface accuracy of the mounting surface can be increased. Polishing can be performed by a commonly used method such as a diamond grindstone.

A vacuum suction apparatus was produced by the above-described manufacturing method. The shape of the vacuum suction device was a mounting portion diameter of 297 mm, a mounting portion thickness of 1 mm, a frame portion and a supporting portion diameter of 310 mm, a frame portion thickness of 2 mm, and a supporting portion thickness of 2 mm. A wafer having a suction hole (diameter 3 mm) formed at the center of the concave portion of the frame and a distance from the center of 50, 75, 100, and 125 mm was prepared, and a wafer (diameter 300 mm, thickness 20 μm) adsorption test. In the adsorption test, 10 wafers were adsorbed to check for wrinkles and breakage defects. Table 1 shows the test results.

Wrinkles and damage did not occur when the suction hole was in the center, but other defects occurred.

Next, the vacuum suction device was manufactured by changing the thickness of the mounting portion. The shape of the vacuum suction device is 297 mm in diameter of the mounting part, 310 mm in diameter of the frame part and the supporting part, 2.5 mm in thickness of the frame part, 2 mm in thickness of the supporting part, and manufactured with different thicknesses of the mounting part did. Alumina sintered body is used as the frame, alumina powder (average particle size 125 μm), glass powder (aluminosilicate glass, average particle size: 20 μm, softening point 950 ° C.) is used as the porous material, Formed. As the support portion, an aluminum-based composite material (MMC) using an alumina sintered body and silicon carbide as a reinforcing material was used. The aluminum-based composite material is a commercially available silicon carbide powder, which is formed into a preform with a ceramic filling rate of 60% by volume, and then heat-treated at 750 ° C. in nitrogen to form an aluminum alloy (JIS AC8A). What was infiltrated into the reforming was used. Ten pieces of each were produced, and the number of defects in which cracks occurred in the mounting portion was examined. In addition, the numerical value of the said average particle diameter (D50) is measured with the laser diffraction type particle size distribution measuring apparatus. The production results are shown in Table 2.

Most of the fabricated products were good in yield. However, when the thickness of the mounting portion was 0.2 mm, the mounting portion was broken when the mounting portion was processed or used.

As a comparative example, an attempt was made to produce a vacuum adsorption device having the same shape as the above production example by a method of joining a conventional ceramic porous body and a ceramic dense body using a glassy bonding material. When the ceramic porous body and the ceramic dense body are joined together, the porous body and the frame portion are polished together to form the mounting portion. Since a gap inevitably exists in the joint portion of the porous body, poor polishing occurred in that portion. Therefore, such a method is not practical because the yield is poor and the accuracy of the mounting surface is not sufficient.

FIG. 1 is a schematic view showing a typical example of the vacuum suction device of the present invention. Fig.1 (a) is the top view seen from the mounting surface side of a vacuum suction apparatus, FIG.1 (b) is an arrow line view of the AA cross section in Fig.1 (a), and FIG. c) is an arrow view seen from the side A in FIG. FIG. 2 is a schematic view of the frame portion. Fig.2 (a) is a top view seen from the mounting surface side (B side in FIG.2 (b)), FIG.2 (b) is an arrow directional view of the BB cross section in Fig.2 (a). FIG. 2 (c) is a plan view seen from the side of the joint surface with the support portion (c side in FIG. 2 (b)). FIG. 3 is a schematic view of the support portion. Fig.3 (a) is the top view seen from the joint surface side, FIG.3 (b) is an arrow line view of CC cross section in Fig.3 (a). FIG. 4 is a schematic view showing another example of the vacuum suction device of the present invention. 4A is a plan view seen from the mounting surface side of the vacuum suction device, and FIG. 4B is a cross-sectional view taken along the DD line in FIG. c) is an arrow view seen from the second side in FIG.

Explanation of symbols

1: mounting part 1a: mounting surface 10: vacuum suction device 2: frame part 3, 13: handle part 4: suction hole 5, 15: first suction groove 6: second suction groove 7: support part

Claims (5)

A mounting portion made of a ceramic porous body having a mounting surface for mounting a substrate;
A frame portion made of a substantially concave dense ceramic surrounding the mounting portion;
A support part for supporting the frame part;
A vacuum suction device for transporting a substrate comprising:
A suction hole provided in the bottom surface of the concave portion of the frame portion, directly communicating with the substantially central pore of the placement portion;
A first suction groove that communicates with the placement portion through the suction hole, and that is provided on a joint surface of the frame portion or the support portion;
The vacuum suction device is characterized in that the mounting portion and the frame portion are directly joined without a gap. The vacuum suction device according to claim 1, wherein a thickness of the placement portion is 2 mm or less, and a total thickness of the vacuum suction device including the placement portion is 5 mm or less. The second suction groove provided on the bottom surface of the concave portion of the frame portion that communicates directly with both the suction hole and the air hole of the placement portion, and communicates with the first suction groove via the suction hole. The vacuum suction apparatus according to 1 or 2. The vacuum suction device according to claim 1, wherein a material of the support portion is a metal matrix composite material (MMC) using ceramics as a reinforcing material or a dense ceramic. Introducing a mixture of ceramic powder and ceramic porous body raw material containing a ceramic powder and a binder into a substantially concave frame, and molding a molded body;
Heating the molded body together with the frame to a temperature at which the binder melts to obtain a ceramic porous body, and directly bonding the ceramic porous body and the frame with the binder without any gaps;
Joining the frame part and the support part;
Polishing the frame part and the ceramic porous body together to form a mounting part;
The manufacturing method of the vacuum suction apparatus characterized by including.

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