JPH11226833A - Adsorptive plate for vacuum chuck and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve flatness of an adsorptive surface at adsorptive time, so that deformation of an adsorbed object at adsorptive time can be suppressed to a minimum limit. SOLUTION: This constitution is formed such that in a peripheral part of adsorptive plate 4 formed with a surface flat and of porous body having many through holes communicating with obverse/reverse both surfaces, a non- ventilation layer 4a interrupting circulation of air is formed, by sucking air from a reverse surface of the adsorptive plate 4, a sucked object W is adsorbed to an adsorptive surface 4c. Of a surface of this adsorptive plate 4, in a peripheral region excepting the non-ventilation layer 4a, a non-ventilating seal part 4d is formed, which is continued to the non-ventilation layer 4a to be thinner than a thickness of the adsorptive plate 4 further flush with the adsorptive surface 4c. Accordingly, the adsorbed object W, when it is arranged so that its peripheral part is mounted on an internal peripheral side of the seal part 4d, is almost prevented from being deformed at adsorptive time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum chuck for adsorbing an object to be adsorbed, and more particularly to a vacuum chuck suction plate and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a suction plate of a vacuum chuck, there has been known a plate formed of a porous material having a large number of through holes communicating with both front and back surfaces. Then, while the outer peripheral surface of the suction plate is sealed, air is sucked from the back surface of the suction plate to adsorb an object to be suctioned such as a wafer on the surface of the suction plate.

As a typical example of the above-mentioned vacuum chuck,
There is one shown in FIG. 8 or FIG. In the vacuum chuck shown in FIG. 8, a lower surface of a suction plate 12 made of a porous material also formed in a disk shape is fixed to an upper surface side of a chuck plate 11 formed in a disk shape. A non-breathable layer 12a having no breathability is formed on the outer peripheral surface of the suction plate 12 of this type by injecting a synthetic resin. This non-breathable layer 12
a, the outer peripheral surface of the suction plate 12 is sealed,
The inner peripheral portion surrounded by the second non-venting layer 12a is a venting region 12b.
Becomes The surface of the suction plate 12 corresponding to the ventilation area 12b is a suction surface 12c for sucking the object W. The object W to be adsorbed is arranged such that the surface facing the adsorption surface 12c covers the entire adsorption surface 12c, and the outer peripheral portion of the object to be adsorbed W approaches the upper surface of the non-ventilated layer 12a.
Then, by sucking air from the chuck plate 11 side by driving the vacuum source, the suction target W is suction-held on the suction surface 12c of the suction plate 12. Further, as described above, the object W is disposed so as to cover the entire suction surface 12c,
The air suction force from the chuck plate 11 acts on the object W efficiently.

Further, the vacuum chuck shown in FIG.
Is formed, and a disc-shaped suction plate 14 made of a porous material is housed in the housing recess 13a. In this type of vacuum chuck, the suction plate 14 is fixed to the chuck plate 13 by applying an adhesive 15 between the inner peripheral surface of the accommodation recess 13 a and the outer peripheral surface of the suction plate 14. Further, the outer peripheral portion of the suction plate 14 is sealed by the adhesive 15 layer. Therefore, in this type of vacuum chuck, the entire suction plate 14 is a ventilation area 14a. The object W to be sucked has a surface facing the suction surface 14b covering the entire suction surface 14b, and an outer peripheral portion of the object W to be sucked is formed in the housing recess 1 of the chuck plate 13.
3a is arranged so as to reach the outer edge. Then, by sucking air from the chuck plate 13 side by driving the vacuum source, the suction target W is sucked on the suction surface 14b of the suction plate 14. Further, as described above, the object W to be adsorbed is
By being arranged so as to cover the entirety, the air suction force from the chuck plate 13 side efficiently acts on the adsorption target W.

[0005]

However, in the conventional vacuum chuck shown in FIG. 8, when the air is sucked from the chuck plate 11 by the driving of the vacuum source and the object W is sucked on the suction surface 12c, The air suction acts on the ventilation area 12b of the suction plate 12. On the other hand, since the non-breathable layer 12a does not have air permeability, no air suction force acts on the non-breathable layer 12a. Further, the ventilation region 12b and the non-venting layer 12a are formed continuously and integrally.

[0009] Therefore, as shown in FIG. 9, the ventilation area 12 b of the suction plate 12 and the non-venting layer 12 a
Then, the suction surface 12 is deformed toward the chuck plate 11 toward the center of the suction surface 12c from the boundary. The degree of this deformation depends on the suction plate 12.
The suction surface 1 corresponding to the ventilation area 12b varies depending on the material, porosity, air suction force from the chuck plate 11, and the like.
The surface of 2c is, for example, 0.1 mm in comparison with the surface of the non-breathable layer 12a.
It is deformed toward the chuck plate 11 side by about 5 μm.

[0007] In this case, the outer peripheral portion of the object W is placed on the non-venting layer 1 so that the air suction force acts on the object W efficiently.
2a, the suction plate 1
With the deformation from the surface of the second non-breathable layer 12a to the suction surface 12c, the suction target W is deformed along the deformed surface during suction.

The above problem cannot be solved even if the flatness between the surface of the non-ventilated layer 12a and the suction surface 12c is increased in the vacuum chuck shown in FIG. .

Similarly, in the conventional vacuum chuck shown in FIG. 10, at the time of suction, as shown in FIG. 11, the suction plate 14 is moved from the boundary of the chuck plate 13 to the recess 13a of the chuck plate 13 toward the center of the suction plate 14. Due to all the deformations, the object W is deformed along the deformed surface.

If the object W has high rigidity, the object W will not be deformed as described above even if the suction plates 12 and 14 are slightly deformed. If the object W is not required to have high accuracy, the above deformation of about 0.5 μm does not pose a problem.

However, a vacuum chuck using a suction plate made of a porous material has been frequently used in the semiconductor manufacturing process in recent years. Therefore, in the case where a precision of the order of submicrons is required, such as a wafer or the like, and when a thin plate-shaped object that is easily bent is used as the object to be sucked W, problems such as a decrease in accuracy of the object to be sucked W and a product defect occur. Therefore, the slight deformation described above also becomes a serious problem.

The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the flatness of a suction surface at the time of suction, thereby minimizing deformation of an object to be suctioned at the time of suction. It is an object of the present invention to provide a vacuum chuck suction plate and a method for manufacturing the same.

It is another object of the present invention to further improve the flatness of the suction surface during suction, and to further easily manufacture such a suction plate of a vacuum chuck. .

[0014]

According to the first aspect of the present invention, there is provided a porous body having a flat surface and a large number of through-holes communicating with both front and back surfaces. The suction plate thus formed is a suction plate of a vacuum chuck which sucks air from the back surface and sucks an object to be suctioned on the front surface by sucking air from the back surface in a state where air circulation between the outer peripheral surface and the outside is prohibited. In the outer peripheral area of the surface, a non-breathable seal portion which is thinner than the thickness of the suction plate and is flush with the surface of the suction plate was provided.

When the suction plate is formed of a porous material by the above means, when air is sucked from the back surface of the suction plate,
Due to the air suction force, the front surface of the suction plate is slightly crushed toward the back surface. Although most of the surface of the suction plate is crushed while maintaining the flatness, the outer peripheral side of the surface of the suction plate is deformed due to factors such as a non-ventilated layer being formed or being fixed with an adhesive. Since the deformation is suppressed, the suction plate is deformed so as to fall obliquely from the outer peripheral side of the suction plate to the suction surface side where the deformation is suppressed. But,
In the present invention, since the non-breathable seal portion is provided at the obliquely deformed portion, the outer peripheral portion of the object to be adsorbed is disposed inside the seal portion surface avoiding the obliquely deformed portion. In addition, it is possible to prevent deformation of the object to be adsorbed when the object is adsorbed. Of course, by arranging the outer peripheral portion of the adsorbed object so as to approach the seal portion, air leakage from between the surface of the adsorbing plate and the adsorbed object is prevented, and the air suction force is efficiently applied to the adsorbed object. Can work.

According to the second aspect of the present invention, the flow of air is blocked to the outer peripheral portion of the suction plate formed of a porous body having a flat surface and a large number of through-holes communicating with the front and back surfaces. Forming a non-venting layer, in the suction plate of a vacuum chuck that suctions an object to be suctioned to the surface by sucking air from the back surface of the suction plate, in the outer peripheral region of the surface of the suction plate except the non-venting layer, The non-breathable layer was provided with a non-breathable seal portion that was thinner than the thickness of the suction plate and was flush with the surface of the suction plate.

In the case where the suction plate is formed of a porous body by the above means, when air is sucked from the back surface of the suction plate,
Due to the air suction force, the front surface of the suction plate is slightly crushed toward the back surface. Although most of the surface of the suction plate is crushed while maintaining its flatness, the portion of the surface of the suction plate where the air-impermeable layer is formed is not crushed by the air suction force. The portion corresponding to the non-ventilated layer is not deformed. Therefore, on the outer peripheral side of the surface of the suction plate, the suction plate is deformed so as to be inclined obliquely inward from the inner peripheral end of the non-permeable layer. However, in the present invention, since the non-breathable seal portion is provided in the obliquely deformed portion, the outer peripheral portion of the object to be adsorbed is arranged inside the seal portion surface avoiding the obliquely deformed portion. This can prevent deformation of the object to be adsorbed when the object is adsorbed. Of course, by arranging the outer peripheral portion of the adsorbed object so as to approach the seal portion, air leakage from between the surface of the adsorbing plate and the adsorbed object is prevented, and the air suction force is efficiently applied to the adsorbed object. Can work.

According to a third aspect of the present invention, in the suction plate of the vacuum chuck according to any one of the first and second aspects, the seal portion is formed by injecting a sealing material into the suction plate.

According to the above-mentioned means, in addition to the function of claim 1 or claim 2, the ventilation region on the surface of the suction plate and the sealing portion are different from the case where the seal portion is provided separately from the porous body constituting the suction plate. It is difficult to form a step at the boundary between the two, and the flatness of the surface of the suction plate is easily obtained. As a result, the object to be absorbed is prevented from being deformed due to a step at the boundary.

According to a fourth aspect of the present invention, in the suction plate of the vacuum chuck according to the second aspect, the non-venting layer and the seal portion are formed by injecting the same sealing material into the suction plate.

By the above means, in addition to the function of claim 2,
Compared to the case where the seal portion is provided separately from the porous body constituting the suction plate, a step is less likely to be formed at the boundary between the ventilation region and the seal portion on the surface of the suction plate, and the flatness of the surface of the suction plate is reduced. It will be easier. As a result, the object to be absorbed is prevented from being deformed due to a step at the boundary. In addition, the non-breathable layer can be formed together with the seal portion using the same sealing material, and the manufacture of the suction plate is simplified.

According to a fifth aspect of the present invention, in the suction plate of the vacuum chuck according to any one of the third and fourth aspects, the Young's modulus of the sealing material and the Young's modulus of the sealing portion and the porous body are compared. The Young's modulus was set to be sufficiently smaller than the Young's modulus of the porous body so that the Young's modulus was almost equal to the Young's modulus.

According to the above-mentioned means, in addition to the function of the third or fourth aspect, the Young's modulus of the seal portion becomes substantially equal to the Young's modulus of the porous body constituting the suction plate. As a result, the deviation of the actually formed cutting surfaces of the seal portion and the other surface with respect to the surface through which the blade passes when cutting the surface of the suction plate is substantially equal, and the flatness of the surface of the suction surface is improved. I do. In addition, at the time of adsorption of an object to be adsorbed, at the boundary portion between the inner peripheral side of the seal portion and the surface of the adsorbing plate, the degree to which the adsorbing plate is crushed becomes equal, and a step between the inner peripheral side of the seal portion and the surface of the adsorbing plate also occurs. Is suppressed.

According to a sixth aspect of the present invention, in the suction plate of the vacuum chuck according to the fifth aspect, the porous body is formed of sintered fluororesin, and the sealing material is silicon resin. By the above means, in addition to the function of claim 5, the adsorbing plate is formed of sintered fluororesin having low hardness, so that the object to be adsorbed is held flexibly at the time of adsorption, and the damage of the object to be adsorbed at the time of adsorption is precise. Can be prevented.

According to a seventh aspect of the present invention, in the suction plate of the vacuum chuck according to any one of the first to sixth aspects, the thickness of the seal portion is controlled so as not to be smaller than the particle size of the porous body. And almost the same.

According to the above means, in addition to the function of any one of the first to sixth aspects, the seal portion is formed extremely thin, so that the seal portion can be connected to the porous portion forming the suction plate during suction. In the same way, the inner peripheral side of the seal portion can be more reliably prevented from being deformed.

According to the eighth aspect of the present invention, the sealing material is applied to the outer peripheral area of the surface of the suction plate formed of a porous body having a flat surface and a large number of through-holes communicating with the front and back surfaces. The method includes a step of applying, a step of wiping the sealing material from the surface of the suction plate after the application, and a step of finishing the surface of the suction plate after the wiping.

By the above means, a sealing material is injected into the outer peripheral region of the surface of the suction plate formed of a porous body having a flat surface and a large number of through-holes communicating with the front and back surfaces. The part becomes a seal part. When forming the seal portion, as described above, the sealing material is applied to the inside of the porous body by capillary action automatically by applying the sealing material, so that the formation of the seal portion is extremely simple. . In addition, the post-processing can be performed simply by wiping off the sealing material remaining on the surface of the suction plate and performing the finishing process.

According to the ninth aspect of the present invention, the outer peripheral area of the surface of the suction plate and the outer periphery of the suction plate formed of a porous body having a flat surface and a large number of through holes communicating with both the front and back surfaces. The method includes a step of applying the same sealing material to the surface, a step of wiping the sealing material from the surface and the outer peripheral surface of the suction plate after the application, and a step of finishing the surface of the suction plate after the wiping.

By the above means, the outer peripheral area of the surface of the adsorbing plate and the outer peripheral surface of the adsorbing plate formed of a porous body having a large number of through-holes communicating with both front and back surfaces are formed to be the same. A sealing material is injected, and the injected portion becomes a seal portion and a non-venting layer. When forming the sealing portion and the non-ventilating layer, the sealing material is automatically penetrated into the porous body by capillary action by applying the sealing material as described above. The formation becomes extremely simple. In addition, the post-processing is simple because the sealing material remaining on the surface of the suction plate and the outer peripheral surface may be wiped off and finished. Further, the sealing portion and the non-venting layer can be formed at the same time, which can facilitate the production of the suction plate.

According to the tenth aspect of the present invention, by heating the outer peripheral region of the surface of the suction plate formed of a porous body having a flat surface and a large number of through holes communicating with the front and back surfaces. The method includes a step of melting and forming an air-impermeable seal portion in an outer peripheral region of the surface, and a step of finishing the surface of the suction plate after the formation of the seal portion.

By the above means, the sealing portion is formed by heating and melting the outer peripheral area of the surface of the suction plate formed of a porous body having a large number of through-holes communicating with both front and back surfaces. Since it can be formed, it is not necessary to use another sealing material for forming the seal portion.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] A first embodiment will be described below with reference to FIGS.

As shown in FIG. 1, the vacuum chuck 1 of the present embodiment includes a chuck body 2 formed in a disk shape. The chuck body 2 has a recess 2a that is open on the upper surface, and an air suction port 2b that communicates the recess 2a with the lower surface of the chuck body 2 at the center of the recess 2a.
Are formed. The air suction port 2b is connected to a vacuum source via a pipe (not shown). That is, the air suction port 2
b functions as a connection part for connecting to a vacuum source.

On the upper surface of the chuck body 2, the recess 2a is provided.
The lower surface of the chuck plate 3 is fixed so as to close the upper opening side of the chuck plate 3. The chuck plate 3 is formed in the same disk shape as the chuck body 2, and the chuck body 2 and the chuck plate 3 constitute a chuck body of the vacuum chuck 1. In this embodiment, the chuck body 2 and the chuck plate 3 are made of a metal material such as aluminum.

On the upper surface of the chuck plate 3, there are formed a plurality of circular grooves 3a, each having a circular center having the center of the disk shape and having different diameters, and opening upward. In the present embodiment, three annular grooves 3a are provided. Each annular groove 3a
Communication holes 3b for communicating the lower surface of the annular groove 3a and the lower surface of the chuck plate 3 are formed at appropriate locations. Therefore, when an air suction force is generated from a vacuum source, air above the chuck plate 3 is sucked through the annular grooves 3a, the communication holes 3b, the recesses 2a, and the air suction ports 2b. That is, each annular groove 3a, each communication hole 3b, and the recess 2a form an air passage that reaches the air suction port 2b as a connecting portion.

On the upper surface of the chuck plate 3, the lower surface of a suction plate 4 formed to have the same disk shape as the chuck body 2 and the chuck plate 3 is fixed. In the present embodiment, the fixing of the suction plate 4 to the chuck plate 3 is performed by applying an adhesive to the outer peripheral region on the lower surface of the suction plate 4.
Both the upper and lower surfaces of the suction plate 4 are formed flat.

Therefore, a specific configuration of the suction plate 4 will be described below. The adsorbing plate 4 is made of a porous body made of a sintered fluororesin, more specifically, a sintered trifluoride resin. The average diameter of the pores formed inside the porous body is approximately 100 μm, The modulus is 42% and the Young's modulus is almost 40k
g / mm ² .

A non-breathable layer 4a having no breathability is formed on the outer peripheral surface of the suction plate 4. The outer peripheral surface of the suction plate 4 is sealed by the non-venting layer 4a, and the non-venting layer 4a of the suction plate 4 is sealed.
The inner peripheral portion surrounded by is a ventilation region 4b. The surface of the suction plate 4 corresponding to the ventilation area 4b is a suction surface 4c for sucking the object W to be sucked. Non-breathable layer 4a
Is formed by infiltrating, for example, a silicone resin as a sealing material into the outer peripheral portion of the suction plate 4. Since the Young's modulus of the silicone resin is sufficiently small, approximately 1/100 of the Young's modulus of the sintered trifluoride resin constituting the adsorbing plate 4, the increase in the Young's modulus due to the injection of the silicone resin into the non-venting layer 4a is caused by an increase in the ventilation region. This is negligible compared to the Young's modulus of 4b. That is, in practice, the ventilation region 4b and the non-breathable layer 4a may be considered to have substantially the same Young's modulus.

The adsorbing plate 4 is connected to the non-venting layer 4a.
Is provided with an annular seal portion 4d extending toward the suction surface 4c. The seal portion 4d and the suction surface 4c form the same plane. The seal portion 4d is configured by impregnating, for example, a silicone resin as a sealing material into the outer peripheral portion of the upper surface of the suction plate 4. That is, the seal portion 4d itself has the same properties as those of the non-ventilated layer 4a, and in fact, the seal portion 4d and the vent region 4b may be considered to have substantially the same Young's modulus.

As shown in FIG. 2, the thickness A of the seal portion 4d
Is set to be at least smaller than the thickness B of the suction plate 4 and within a range of not less than the particle diameter (100 μm) of the porous body constituting the suction plate 4. In the present embodiment, the thickness of the seal portion 4 d is set. A is set to a minimum of 100 μm. The width C in the planar direction of the seal portion 4d is such that, when the wafer W is placed on the suction surface 4c, the suction surface 4c except for the seal portion 4d is covered by the wafer W, and the wafer W is sealed. It is set so as to reach the upper surface of the portion 4d and to secure a predetermined clearance D.

As described above, the thickness A of the seal portion 4d is
At least the thickness B of the suction plate 4 is smaller than the thickness B of the suction plate 4.
Is set within the range of the particle diameter (100 μm) or more of the porous body constituting the above, but the thickness A is preferably smaller in the range. Specifically, it is preferably in the range of 100 μm to 1 mm, and more preferably in the range of 100 μm to 500 μm. This is because even if the seal portion 4d has substantially the same Young's modulus as the ventilation region 4b, the Young's modulus of the seal portion 4d also increases, although slightly, so that the thinner the adsorbing surface 4c and the surface of the seal portion 4d, the thinner it is. This is because the flatness of the continuous surface is improved.

Next, a method of manufacturing the suction plate 4 will be described. The adsorbing plate 4 of the present embodiment includes a first step of forming a base of the adsorbing plate 4 made of a porous body, and a second step of forming a non-venting layer 4a on an outer peripheral portion of the base of the adsorbing plate 4 after the first step. It is manufactured by a manufacturing method including a process, a third process of forming the seal portion 4d after the second process, and a fourth process of finishing the suction surface 4c and the upper surface of the seal portion 4d after the third process. .

That is, in the first step, the average particle size is about 10
A molding material is filled with a particle material of trifluoride resin having a diameter of 0 μm, compression-molded, and heated and sintered to form a prototype of the adsorption plate 4 made of sintered trifluoride resin as a porous body. You. The base of the suction plate 4 is formed by cutting this prototype into a predetermined shape, in this embodiment, into a disk shape.

In the second step, a silicone resin is applied to the entire outer peripheral portion of the suction plate 4. As a result, the inside of the suction plate 4 is automatically and automatically penetrated from the outer peripheral surface of the suction plate 4 by capillary action, and the permeated region becomes the non-venting layer 4a. The degree of penetration of the silicone resin into the porous body constituting the suction plate 4 can be adjusted by the viscosity of the silicone resin. Therefore, the thickness E of the non-breathable layer 4a is an appropriate thickness determined by the viscosity of the silicone resin. Thereafter, the silicon resin remaining on the outer peripheral portion of the suction plate 4 is wiped off.

In the third step, a silicone resin is applied to a region having a width C shown in FIG.
Then, the inside of the attraction plate 4 is automatically and automatically soaked from the upper surface of the attraction plate 4 by a capillary phenomenon, and the infiltrated region becomes the seal portion 4d. As described above, the degree of penetration of the silicone resin into the adsorption plate 4 can be adjusted by the viscosity of the silicone resin. Therefore, the seal portion 4
The thickness A of d is an appropriate thickness determined by the viscosity of the silicone resin. Thereafter, the silicon resin remaining on the upper surface of the suction plate 4 is wiped off. In the third step, since the seal portion 4d is cut and finished in the next fourth step, the thickness of the seal portion 4d to be finally obtained in consideration of the amount cut in the next step in the seal portion 4d It is formed thicker than A.

The second and third steps can be performed simultaneously. That is, for example, after applying the silicone resin to the entire outer peripheral portion of the suction plate 4 and the outer peripheral portion of the upper surface of the suction plate 4, respectively, it is also possible to wipe off the remaining silicon resin.

In the next fourth step, the suction surface 4c of the suction plate 4
An operation of flat-cutting the side with a milling cutter is performed.
Specifically, this cutting includes each step of rough cutting, medium cutting, and finish cutting. First, in rough cutting, the suction surface 4c side of the suction plate 4 is cut several times with a cutting amount of approximately 10 μm to remove relatively large irregularities on the suction surface 4c side. In medium cutting, cutting is performed several times while gradually reducing the cutting depth so that the size of burrs generated in the through-hole portion on the cutting surface is gradually reduced. Finally, as finish cutting,
Cutting is performed with a cutting amount of approximately 1 μm. By this finish cutting, the suction surface 4c is finally formed. Similarly, the thickness A of the seal portion 4d is finished to 100 μm.

As a result of measuring the flatness of the suction surface 4c formed as described above, the non-venting layer 4a and the sealing portion 4d were measured.
Could protrude from the suction surface 4c to 0 to 0.2 μm.

Next, the operation of the vacuum chuck 1 configured as described above will be described. The wafer W is arranged on the upper surface of the suction plate 4. The wafer W is arranged so as to cover the entire suction surface 4c of the suction plate 4 and to reach the upper surface of the seal portion 4d and to secure a predetermined clearance D on the outer peripheral side of the upper surface of the seal portion 4d.

In this state, when an air suction force is generated from the vacuum source, air in the ventilation area 4b of the suction plate 4 passes through each annular groove 3a, each communication hole 3b, the recess 2a, and the air suction port 2b. Is sucked.

Here, as described above, the wafer W covers the entire suction surface 4c, and the outer peripheral portion of the wafer W is in contact with the upper surface of the seal portion 4d. Therefore, the contact surface between the wafer W and the seal portion 4d acts as a seal, and almost no outside air is sucked into the ventilation area 4b. Thus, the air suction force efficiently acts on the wafer W, and the wafer W is securely held by suction on the suction surface 4c.

The ventilation area 4b of the suction plate 4 is made of a porous material and has a large number of holes. Therefore, as shown in FIG. 3, the ventilation area 4b of the suction plate 4 is moved in the suction direction by the air suction force, that is, 0.5 μm toward the chuck plate 3 side.
The shape is crushed by about m. On the other hand, the non-breathable layer 4a of the suction plate 4 is basically made of the same porous body as the breathable area 4b, but the silicone resin is injected into the porous body so that the silicone resin is in a large number of through-holes. Due to intervening, air permeability is lost. Therefore, no stress is generated in the suction direction, that is, the direction in which the non-venting layer 4a is crushed toward the chuck plate 3 by the air suction force, and the same thickness as that in the non-sucking state is maintained. Since the ventilation region 4b and the non-breathable layer 4a are integrally formed, a portion corresponding to the seal portion 4d of the surface of the suction plate 4 on the suction surface 4c side as shown in FIG. Then, the suction surface 4c is gradually crushed toward the center of the chuck plate 3 toward the center portion, and is deformed so as to become flat from the middle. This deformation occurs in a very narrow range within the area of the predetermined clearance D in FIG.

Here, the outer peripheral edge of the wafer W is disposed on the inner peripheral side of the seal portion 4d with a predetermined clearance D so as to avoid the deformed portion of the seal portion 4d. The wafer W is not deformed regardless of the deformation of the portion 4d. That is, the width C in the planar direction of the seal portion 4d is set so as to include a deformed portion at the time of suction and a flat portion that can form a flat surface together with the suction surface 4c at the time of suction. It is the installation portion of the outer periphery of W. Therefore, the wafer W is sucked and held by the vacuum chuck 1 while maintaining a flat state without being carelessly bent, and is transferred to a predetermined wafer W processing step.

Next, effects obtained in the first embodiment will be described. (1) A non-breathable seal portion 4d which is thinner than the thickness of the suction plate 4 and is flush with the upper surface of the suction surface 4c is provided in the outer peripheral region of the upper surface of the suction plate 4. Thereby, on the upper surface of the suction plate 4, the oblique deformation from the boundary between the seal portion 4d and the non-ventilated layer 4a toward the suction surface 4c is prevented from being caused on the outer peripheral side of the seal portion 4d.
That is, the operation is performed in a small range within the predetermined clearance D, and the suction surface 4c side of the upper surface of the seal portion 4d forms a flat surface together with the suction surface 4c. Therefore, by arranging the outer peripheral portion of the wafer W on the inner peripheral side of the seal portion 4d so as to avoid the deformed portion of the seal portion 4d, the wafer W can be suction-held without being deformed at the time of suction.

(2) By arranging the outer peripheral portion of the wafer W on the inner peripheral side of the seal portion 4d so as to avoid the deformed portion of the seal portion 4d, the entire suction surface 4c is covered with the wafer W, Air leakage from between the upper surface of the plate 4 and the wafer W is prevented, and the air suction force can be applied to the wafer W efficiently.

(3) The sealing portion 4d was formed by injecting a sealing material made of a silicone resin into the porous material constituting the suction plate 4. Thereby, compared with the case where the seal portion 4d is provided separately from the porous body constituting the suction plate 4,
At the boundary between the suction surface 4c and the seal portion 4d on the upper surface of the suction plate 4, it is difficult to form a step, and the surface of the suction plate 4 is more easily flat. As a result, the wafer W is prevented from being deformed due to a step at the boundary.

(4) The non-ventilating layer 4a and the sealing portion 4d are
The suction plate 4 was formed by injecting the same sealing material, here a silicone resin. This makes it possible to simultaneously form the non-breathable layer 4a and the seal portion 4d when manufacturing the suction plate 4, simplifying the manufacture of the suction plate 4, and eliminating the need to prepare a plurality of types of sealing materials. Thus, inventory management and the like become easy.

(5) The Young's modulus of the sealing material made of silicone resin at the time of forming the seal portion 4d is
The Young's modulus of the porous body constituting the adsorbing plate 4 is substantially smaller than the Young's modulus of the porous body constituting the adsorbing plate 4, so that the Young's modulus of the porous body constituting the adsorbing plate 4 is substantially equal to that of the porous body constituting the adsorbing plate 4.
It was set to 1/00. Thereby, the displacement of the actually formed cutting surfaces of the seal portion 4d and the suction surface 4c with respect to the surface through which the blade passes when cutting the surface of the suction plate 4 becomes substantially equal, and the suction surface 4c and the seal portion 4d are displaced. The surface flatness is improved. Further, at the time of suction of the wafer W, the extent to which the suction plate 4 is crushed is equal at the boundary between the inner peripheral side of the seal portion 4d and the suction surface 4c, and the step between the inner peripheral side of the seal portion 4d and the suction surface 4c is reduced. Generation can also be suppressed.
That is, the boundary portion between the seal portion 4d and the suction surface 4c can always be highly flat regardless of whether the suction is performed or not.

(6) Since the porous body constituting the suction plate 4 is formed of a low-hardness sintered fluororesin, in this case, a sintered trifluoride resin, the wafer W is held flexibly during suction. Therefore, it is possible to reliably prevent damage to the wafer W during suction.

(7) The thickness A of the seal portion 4d is substantially the same as the particle size of the porous body constituting the suction plate 4 (in the present embodiment, 1 mm).
00 μm). As described above, since the seal portion 4d is formed extremely thin, the seal portion 4d bends at the time of suction in the same manner as the porous body portion forming the suction plate 4, and the seal portion 4d has an inner peripheral side. The flatness of the suction surface 4c can be further improved.

(8) When forming the non-venting layer 4a and the sealing portion 4d on the suction plate 4, by applying a sealing material made of silicone resin, the inside of the porous body is naturally spontaneously exploited by the capillary phenomenon. I tried to penetrate. For this reason, the formation of the non-venting layer 4a and the sealing portion 4d becomes extremely simple. In addition, the post-processing is simple because the sealing material remaining on the surface and the outer peripheral surface of the suction plate 4 may be wiped off and finished.

[Second Embodiment] Next, a second embodiment will be described with reference to FIG. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on differences from the first embodiment.

In the first embodiment, the non-venting layer 4a is formed on the outer periphery of the suction plate 4. However, in the vacuum chuck 5 of the present embodiment, the non-venting layer 4a is not provided on the outer periphery of the suction plate 4.
On the upper surface of the chuck plate 3, an accommodation recess 3c that opens upward is formed. In the present embodiment, the depth of the accommodation recess 3c is formed to be substantially the same as the thickness of the suction plate 4, but it is not always necessary to make them completely match.

The suction plate 4 is housed in the housing recess 3c. The suction plate 4 is fixed in the housing recess 3c by interposing the adhesive 6 between the inner peripheral surface of the housing recess 3c of the chuck plate 3 and the outer peripheral surface of the suction plate 4. Adhesive 6
Is injected after the suction plate 4 is housed in the housing recess 3c. The suction plate 4 may be housed in the housing recess 3c after being applied to at least one of the outer peripheral surface of the suction plate 4 and the inner circumferential surface of the housing recess 3c.

The adhesive 6 layer extends over the entire outer peripheral surface of the suction plate 4 to prevent air leakage from the outer peripheral surface of the suction plate 4 and the boundary between the outer peripheral surface of the suction plate 4 and the seal portion 4d. . Therefore, also in the second embodiment, the non-venting layer 4a
Except for the parts related to the first embodiment, the effects (1) to (3) and (5) to (8) of the first embodiment are obtained, and the following effects are obtained.

(9) Recess 3c formed in chuck plate 3
Since the suction plate 4 is accommodated in the chuck body 2, the positioning of the suction plate 4 with respect to the chuck body 2 is performed, so that the positioning of the suction plate 4 is easy.

(10) The adhesive 6 is applied to the inner peripheral surface of the accommodation recess 3 c of the chuck plate 3 or the outer peripheral surface of the suction plate 4,
While the suction plate 4 is fixed in the accommodation recess 3c, the suction plate 4
Thus, air leakage from the outer peripheral surface of the suction plate 4 and the boundary between the outer peripheral surface of the suction plate 4 and the seal portion 4d can be prevented. Therefore, it is not necessary to separately perform the operation of forming the non-ventilated layer 4a and the operation of fixing the suction plate 4 on the chuck plate 3 as in the first embodiment, and the manufacturing operation can be simplified.

[Third Embodiment] Next, a third embodiment will be described with reference to FIG. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on differences from the first embodiment.

In the first embodiment, a non-breathable layer 4a having a uniform thickness E is formed on the outer periphery of the suction plate 4, and a sealing portion having a uniform thickness A communicating with the non-breathable layer 4a is formed on the outer peripheral edge of the upper surface of the suction plate 4. 4d
However, in the vacuum chuck 7 according to the present embodiment, the non-ventilated layer 4a and the seal portion 4d are taken as one continuous region without particularly uniform thickness, and the non-ventive layer 4a and the seal portion 4d are continuous. It was configured to be able to. However, the seal portion 4d is formed to be thinner toward the inside of the surface of the suction plate 4.

Therefore, also in the third embodiment, the first
The effects (1) to (8) of the embodiment are obtained, and
The following effects are obtained. (11) It is not necessary to make the non-ventilated layer 4a and the seal portion 4d uniform in thickness, and it is not necessary to precisely set the viscosity of the silicone resin when applying a sealing material made of silicone resin. The operation of forming the layer 4a and the seal portion 4d can be simplified.

[Fourth Embodiment] Next, a fourth embodiment will be described with reference to FIG. Note that the same components as those of the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on differences from the second embodiment.

In the second embodiment, the adhesive 6 is formed so as to extend over the entire outer peripheral surface of the suction plate 4, but in the vacuum chuck 8 of the present embodiment, the upper surface of the suction plate 4 and the accommodation recess 3c is formed. The adhesive 6 is applied only to the boundary part. The six layers of the adhesive prevent air leakage from the boundary between the outer peripheral surface of the suction plate 4 and the seal portion 4d.

Therefore, also in the fourth embodiment, (1) to (1) of the first embodiment except for the portion relating to the non-ventilated layer 4a.
The following effects are obtained in addition to the effects (3) and (5) to (8) and the effect (9) of the second embodiment.

(12) After the suction plate 4 is accommodated in the accommodation recess 3c, the adhesive 6 only needs to be applied to the boundary between the outer peripheral surface of the suction plate 4 and the seal portion 4d. In addition to simplification, the amount of the adhesive 6 used can be reduced.

[Fifth Embodiment] Next, a fifth embodiment will be described with reference to FIG. Note that the same components as those of the second embodiment are denoted by the same reference numerals, and the description thereof will be omitted. The description will focus on differences from the second embodiment.

In the second embodiment, six layers of the adhesive are formed so as to spread over the entire outer peripheral surface of the suction plate 4. However, in the vacuum chuck 9 of this embodiment, the suction plate 4 is only stored in the storage recess 3c. The upper surface of the suction plate 4 and the upper surface of the chuck plate 3 around the accommodation recess 3c are set to be flush with each other during the accommodation. An annular pressing plate 10 is provided so as to reach a part of the seal portion 4d on the upper surface of the chuck plate 3 from the upper surface of the chuck plate 3, and the pressing plate 10, the chuck plate 3 and the suction plate 4 are provided.
Is fixed by the adhesive 6, air leakage from between them is prevented.

Therefore, also in the fifth embodiment, (1) to (1) of the first embodiment except for the portion relating to the non-ventilated layer 4a.
The effects (3) and (5) to (8) and the effect (9) of the second embodiment are obtained.

[Other Embodiments] In addition to the above embodiments,
There are other embodiments as follows. The average particle diameter, the average diameter of the through-holes, and the porosity of the porous body forming the adsorption plate 4 may be appropriately changed.

The porous sintered body forming the adsorption plate 4 is not limited to the sintered trifluoride resin, but may be a porous sintered body of a synthetic resin such as a tetrafluoride resin, a nylon resin, a polyacetal resin or the like. It may be. In this case, substantially the same effect can be obtained by using an epoxy resin having a Young's modulus lower than that of the synthetic resin instead of the silicone resin as the sealing material injected at the time of forming the seal portion 4d of each embodiment. It is possible.

The porous sintered body forming the adsorbing plate 4 may be made of a metal material such as sintered copper, sintered aluminum, sintered stainless steel or the like instead of synthetic resin. In this case, as a sealing material to be injected at the time of forming the seal portion 4d of each embodiment, instead of the silicon resin, an epoxy resin or a phenol having a Young's modulus of about 1/100 of the porous sintered body of the metal material is used. It is preferable to use a synthetic resin such as a resin.

The non-breathable layer 4a and the sealing portion 4d
Is not limited to the method of applying a silicone resin, but may be performed by another method. For example, the suction plate 4 may be injected by immersing the suction plate 4 in a silicone resin and positively sucking.

Similarly, as a method of forming the non-venting layer 4a and the sealing portion 4d on the suction plate 4, the following method may be used in addition to using a sealing material such as a silicon resin. That is, the outer peripheral surface and the outer peripheral region of the surface of the suction plate 4 may be melted by heating, and the non-permeable layer 4a and the seal portion 4d may be formed on the outer peripheral surface and the outer peripheral region of the surface. In this case, there is an advantage that it is not necessary to use any sealing material in order to form the non-breathable layer 4a and the seal portion 4d.

Although the example in which the vacuum chucks 1, 5, 7, 8, and 9 are used with the suction surface 4c of the suction plate 4 as the upper surface has been described, an embodiment in which the suction surface 4c is the lower surface is also possible. An embodiment in which the suction surface 4c faces sideways or obliquely is also possible. The shape of the suction plate 4 is not limited to a disk shape, but may be changed as appropriate, such as an elliptical plate shape or a square plate shape.

The material of the non-breathable layer 4a is not related to the deformation of the object to be sucked such as the wafer W, regardless of the material. Therefore, the Young's modulus of the porous body constituting the suction plate 4 is taken into consideration. It can be formed freely without any problem.

The sealing portion 4d is colored and the suction surface 4c
And may be visually distinguished. In this case, by confirming the color of the seal portion 4d, an object to be attracted such as the wafer W can be arranged so as to accurately reach the seal portion 4d. Furthermore, a region of the seal portion 4d that is not deformed at the time of suction is colored so as to be identifiable, and by confirming the color, the bending of the wafer W can be reliably prevented. Needless to say, by performing such color confirmation by a sensor, it is possible to control the wafer W to be automatically arranged at a desired position. The seal portion 4d or the seal portion 4d
In addition to applying a color to identify the specific part inside,
It is also possible to use the color of the sealing material itself injected into d.

The object to be adsorbed is not limited to the wafer W.
A semiconductor chip or the like which requires high accuracy or easily bends may be used. [Technical idea grasped from each embodiment] The technical ideas grasped by each of the above embodiments are listed below. Note that the description of the members and the like in parentheses indicates the corresponding configuration in each embodiment.

A suction plate according to any one of claims 1 to 7, and an air passage (annular groove 3a, communication hole 3b, recess 2) attached to the back surface of the suction plate and communicating with the back surface of the suction plate.
a) and a chuck body (chuck body 2 and chuck plate 3) provided with a connection portion (air suction port 2b) connected to a vacuum source through the air passage. According to this configuration, it is possible to obtain a vacuum chuck having the effects of any one of the first to seventh aspects.

The air suction passage (annular groove 3a, communication hole 3b, recess 2a) communicating with the suction plate according to any one of claims 1 to 7, and the air passage. And a chuck body (chuck body 2 and chuck plate 3) provided with a connection portion (air suction port 2b) connected to a vacuum source through which the suction plate is housed in a housing recess formed in the chuck body. The outer peripheral surface or the outer peripheral edge of the plate was fixed with a non-breathable adhesive. According to this configuration, it is possible to obtain a vacuum chuck having the effects of any one of the first to seventh aspects. Further, since the suction plate is housed in the housing recess, the suction plate is positioned with respect to the chuck body, so that the positioning of the suction plate is easy. Further, there is no need to previously form a non-venting layer on the suction plate, and the manufacture of the suction plate itself is facilitated.

In the method for manufacturing a suction plate of a vacuum chuck according to any one of claims 8 and 9, the sealing material has a Young's modulus of a seal portion substantially equal to a Young's modulus of a porous body. Thus, a method for manufacturing a suction plate of a vacuum chuck using a material having a sufficiently small Young's modulus with respect to the Young's modulus of a porous body. According to this manufacturing method, the step between the suction surface and the surface of the seal portion is almost negligible irrespective of the time of suction or non-suction, and the object to be sucked can always be sucked while being kept flat.

[0091] In the method for manufacturing a suction plate of a vacuum chuck according to any one of claims 8, 9 and 10, the step of finishing the surface of the suction plate includes rough cutting the surface of the suction plate. A method for manufacturing a suction plate of a vacuum chuck, which is a cutting process that is performed with increasing cutting accuracy to finish cutting. According to this manufacturing method, the step between the suction surface and the seal portion surface during non-suction is almost negligible.

In the method for manufacturing a suction plate of a vacuum chuck according to the tenth aspect, the outer peripheral surface of the suction plate is melted by performing heating in the same manner as in the method of forming the seal portion, and a ventilation layer is formed on the outer peripheral surface of the suction plate. A method for manufacturing a suction plate of a vacuum chuck formed simultaneously with or before or after the seal portion. According to this manufacturing method, it is not necessary to use any special sealing material for the non-breathable layer and the seal portion formed on the suction plate.

[0093]

As described in detail above, according to the first and second aspects of the present invention, the flatness of the suction surface at the time of suction is improved, and thus the object to be suctioned at the time of suction is improved. Deformation can be minimized.

According to the invention described in claim 3, according to claim 1
Alternatively, in addition to the effect of the second aspect, a step is less likely to be formed at the boundary between the ventilation area and the seal portion on the surface of the suction plate, the flatness of the surface of the suction plate is further improved, and the object to be suctioned is formed at the boundary portion. Deformation due to a step can be prevented.

According to the invention set forth in claim 4, according to claim 2,
In addition to the above effects, it is difficult to form a step at the boundary between the ventilation area and the seal portion on the surface of the suction plate, the flatness of the surface of the suction plate is further improved, and the object to be absorbed is deformed by the step at the boundary. Can be prevented. In addition, the non-breathable layer can be formed together with the seal portion using the same sealing material, and the manufacture of the suction plate is simplified.

According to the invention set forth in claim 5, according to claim 3,
In addition to the effect of claim 4, since the Young's modulus of the seal portion is substantially equal to the Young's modulus of the porous body constituting the suction plate, the seal portion and the sealing portion with respect to the surface through which the blade passes when cutting the surface of the suction plate. The deviation of the actually formed cutting surface of each of the other surfaces becomes substantially equal, and the flatness of the surface of the suction surface is improved. In addition, at the time of adsorption of the object to be adsorbed, at the boundary portion between the inner peripheral side of the seal portion and the surface of the adsorbing plate, the degree to which the adsorbing plate is crushed becomes equal, and a step between the inner peripheral side of the seal portion and the surface of the adsorbing plate also occurs. Is suppressed.

According to the invention described in claim 6, according to claim 5,
In addition to the effect of the above, the adsorbing plate is made of sintered fluororesin with low hardness, so that the adsorbed object is held flexibly during adsorption,
Precise damage to the object to be adsorbed during adsorption can be prevented.

According to the invention of claim 7, according to claim 1,
In addition to the effect of any one of claims 6 to 9, the extremely thin seal portion causes the seal portion to bend at the time of suction in the same manner as the porous portion constituting the suction plate. Circumferential deformation can be more reliably prevented.

According to the eighth aspect of the present invention, the sealing portion of the suction plate in each of the above-mentioned inventions can be formed extremely easily, and the manufacture of the suction plate becomes easy. According to the ninth aspect of the present invention, the sealing portion of the suction plate in each of the above-mentioned inventions can be formed extremely easily, and the manufacture of the suction plate becomes easy. In addition, the seal portion and the non-venting layer can be formed at the same time, which can further facilitate the production of the suction plate.

According to the tenth aspect of the present invention, the sealing portion of the suction plate in each of the above inventions can be formed extremely easily, and the manufacture of the suction plate becomes easy. In addition, there is no need to use a sealing material when forming the seal portion.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a vacuum chuck according to a first embodiment.

FIG. 2 is an enlarged sectional view of a main part of the vacuum chuck shown in FIG. 1 at the time of non-suction.

FIG. 3 is an enlarged cross-sectional view of a main part at the time of suction in the vacuum chuck of FIG. 1;

FIG. 4 is a sectional view showing a vacuum chuck according to a second embodiment.

FIG. 5 is a sectional view showing a vacuum chuck according to a third embodiment.

FIG. 6 is a sectional view showing a vacuum chuck according to a fourth embodiment.

FIG. 7 is a sectional view showing a vacuum chuck according to a fifth embodiment.

FIG. 8 is a sectional view showing a conventional vacuum chuck.

FIG. 9 is an enlarged cross-sectional view of a main part of the vacuum chuck of FIG. 8 during suction.

FIG. 10 is a sectional view showing a conventional vacuum chuck.

FIG. 11 is an enlarged cross-sectional view of a main part at the time of suction in the vacuum chuck of FIG. 10;

[Explanation of symbols]

1, 5, 7, 8, 9 vacuum chuck, 2 chuck body, 3 chuck plate, 4 suction plate, 4a non-permeable layer, 4
b: ventilation area, 4c: suction surface (surface), 4d: seal portion, W: wafer as an object to be sucked.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 04 483: 00 B29L 7:00

Claims (10)

[Claims] 1. A suction plate formed of a porous body having a flat surface and a large number of through-holes communicating with both front and back surfaces in a state in which air circulation between the outer peripheral surface and the outside is prohibited. An adsorbing plate of a vacuum chuck that adsorbs an object to be adsorbed on the surface by sucking air from the back surface, wherein an outer peripheral area of the surface of the adsorbing plate is thinner than the thickness of the adsorbing plate and is flush with the surface of the adsorbing plate. A suction plate of a vacuum chuck provided with a non-breathable seal portion. 2. A non-venting layer for blocking air flow is formed on an outer peripheral portion of an adsorbing plate formed of a porous body having a surface formed flat and having a large number of through holes communicating with both front and back surfaces,
In the suction plate of a vacuum chuck that suctions an object to be suctioned to the surface by sucking air from the back surface of the suction plate, the outer peripheral region of the surface of the suction plate except for the non-ventilated layer,
A suction plate of a vacuum chuck provided with a non-breathable seal portion which is continuous with the non-breathable layer and is thinner than the thickness of the suction plate and is flush with the surface of the suction plate. 3. The suction plate of a vacuum chuck according to claim 1, wherein the sealing portion is formed by injecting a sealing material into the suction plate. 4. The suction plate of a vacuum chuck according to claim 2, wherein the non-ventilated layer and the sealing portion are formed by injecting the same sealing material into the suction plate. 5. The suction plate of a vacuum chuck according to claim 3, wherein the Young's modulus of the sealing material is substantially equal to the Young's modulus of the seal portion and the porous body. The suction plate of the vacuum chuck has a Young's modulus sufficiently smaller than the Young's modulus of the porous body. 6. The suction plate of a vacuum chuck according to claim 5, wherein the porous body is formed of a sintered fluororesin and the sealing material is a silicon resin. 7. The vacuum chuck according to claim 1, wherein the thickness of the seal portion is not smaller than the particle diameter of the porous body and is substantially equal to the suction plate of the vacuum chuck according to claim 1. Suction plate. 8. A step of applying a sealing material to an outer peripheral region of a surface of an adsorption plate formed of a porous body having a flat surface and a large number of through holes communicating with both front and back surfaces, and applying the sealing material. A step of wiping the sealing material from the surface of the suction plate later,
And a step of finishing the surface of the suction plate after the wiping. 9. The same sealing material for the outer peripheral region of the surface of the adsorbing plate and the outer peripheral surface of the adsorbing plate formed of a porous body having a flat surface and a large number of through holes communicating with the front and back surfaces. And a step of wiping a sealing material from the surface and the outer peripheral surface of the suction plate after the application, and a step of finishing the surface of the suction plate after the wiping. 10. An adsorbing plate formed of a porous body having a flat surface and a large number of through-holes communicating with the front and back surfaces is melted by heating the outer peripheral region of the adsorbing plate. And a step of finishing the surface of the suction plate after the formation of the seal portion.