JP7165494B2 - cleaning equipment - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning apparatus, and more particularly, to a cleaning apparatus for cleaning the holding surface of a chuck table that suction-holds a semiconductor wafer (hereinafter simply referred to as "wafer").

In a semiconductor manufacturing process, the back surface of a wafer having a plurality of devices such as ICs and LSIs formed thereon is ground by a grinder to process the wafer to a predetermined thickness. After that, the wafer is diced along the dividing lines to manufacture individual device chips. The device chip thus obtained is packaged by resin sealing and widely used in various electronic devices.

As an apparatus for dicing a wafer, there is a blade-type cutting apparatus in which a thin disk-shaped cutting blade rotating at high speed is cut into the wafer held by suction on a chuck table. In this blade-type cutting device, a porous chuck is built into the chuck table, and the wafer is sucked and held on the chuck table by using the porous material on the table surface and negative pressure to perform processing. (See Patent Document 1, for example).

Further, since the blade-type cutting device cuts the wafer with a width of about 10 μm to 20 μm, a high degree of flatness is required for the wafer suction surface. As described above, since the porous chuck is required to have highly precise flatness, it is necessary to maintain the flatness of the suction holding surface, and the suction holding surface is periodically polished and cleaned.

In polishing and cleaning the porous chuck, the porous chuck is rotated together with the chuck table, and polishing is performed by bringing the rotating porous chuck into contact with the chuck cleaning grindstone. A mixed fluid of cleaning water and air is ejected from an accompanying cleaning nozzle, and the ejected mixed fluid cleans polishing dust and the like moved to the outer peripheral side of the porous chuck.

In so-called two-fluid cleaning, in which a mixed fluid of cleaning water and air is sprayed from a cleaning nozzle, when the mixed fluid is sprayed from a cleaning nozzle onto an object to be cleaned, splashes and mist containing dirt (hereinafter collectively referred to as " Spray") can occur and travel to unexpected locations, adversely affecting other processing equipment and non-water resistant parts such as steel. Therefore, a structure in which a chamber is installed to cover the cleaning nozzle is also known (see, for example, Patent Document 2).

In the cleaning apparatus disclosed in Patent Document 2, in which a chamber is installed to cover the cleaning nozzle, a method is adopted in which the inside of the chamber is exhausted in order to prevent the spray from scattering while avoiding contact with the surface to be cleaned. ing.

As a chamber covering the cleaning nozzle, there is also known a method in which cleaning water is sprayed around the cleaning nozzle to create a pseudo-chamber to prevent spray scattering.

JP-A-8-25209 JP 2015-109324 A

However, the method known in Patent Document 2, in which a chamber is installed to cover the cleaning nozzle and the inside of the chamber is evacuated by exhaust air, has the problem that the structure is complicated, the cost is high, and the structure is large. rice field.

On the other hand, the method of spouting cleaning water around the cleaning nozzle to create a simulated chamber covering the cleaning nozzle has the problem of using a large amount of water.

Therefore, there are technical problems to be solved in order to provide a cleaning device that can clean the surface to be cleaned by eliminating the spray caused by the rising of the spray during cleaning, and that can be reduced in cost and size with a simple structure. A problem arises and the present invention aims to solve this problem.

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above objects. A cleaning apparatus for cleaning, comprising a brush head having a brush protruding toward the surface to be cleaned and mounted on the cleaning nozzle, the brush being approximately on the outer circumference of the jet port when viewed from the bottom surface . To provide a cleaning device which is arranged at equal intervals and drops a spray of the cleaning fluid generated by rebounding on the surface to be cleaned .

According to this configuration, water splashes or sprays made of mist ejected from the ejection port of the cleaning nozzle and bounce off the surface to be cleaned hit the brushes arranged at substantially equal intervals on the outer periphery of the ejection port of the cleaning nozzle. Then, the spray that hits each brush is prevented from dripping along each brush in the brush head and scattering to an unexpected place. In addition, the brushes are arranged between the brushes of the inner brush row and between the brushes of the outer brush row, respectively, so that the brushes surround the entire outer periphery of the nozzle in the radial direction of the cleaning nozzle. can. Moreover, in the radial direction of the cleaning nozzle, even if each brush surrounds the entire outer circumference of the ejection port, a gap for releasing air can be formed between each brush. Therefore, for example, when a mixed fluid of air and cleaning water is jetted from the ejection port of the cleaning nozzle, the water droplets and mist that bounce off the surface to be cleaned are created by the inner brush row and the outer brush row. It hits the wall and drips in the brush head. On the other hand, air can smoothly flow to the outside of the brush head through the gaps between the brushes of the inner brush row and the brushes of the outer brush row. As a result, it is possible to prevent splashes of water splashed from the surface to be cleaned and spray made of mist from scattering to unexpected places.

According to a second aspect of the present invention, there is provided the cleaning device according to the first aspect, wherein the brush is formed by bundling a plurality of thread-like brush elements.

According to this configuration, the brush is easily bent, and each brush element is bent to easily remove dust on the surface to be cleaned. Also, when cleaning the surface of the porous chuck, the brush element penetrates into the pores and removes dirt inside the pores.

The invention according to claim 3 provides the cleaning device according to claim 1 or 2 , wherein the brush head is reciprocally slidable with respect to the cleaning nozzle in the central axis direction of the cleaning nozzle. .

According to this configuration, when cleaning is performed by pressing the brush head against the surface to be cleaned, the amount of sliding of the brush head can be easily adjusted according to the amount of pressing.

According to a fourth aspect of the present invention, in the configuration of the third aspect, a spring member is provided between the brush head and the cleaning nozzle to urge the brush head to protrude toward the surface to be cleaned. A cleaning apparatus is provided, further comprising:

According to this configuration, when cleaning the surface to be cleaned by pressing the brush head against the surface to be cleaned, the amount of sliding of the brush head can be easily adjusted according to the amount of pressing. It is possible to automatically return the brush head to its original position again by the spring force of .

A fifth aspect of the present invention provides the cleaning device according to the second, third, or fourth aspect, wherein the brush element is made of a plastic material.

According to this configuration, a plurality of brush elements made of plastic material are bundled to form a rod-shaped bundled brush element, so that the surface to be cleaned can be cleaned by bringing the bundled brush element into contact with the surface to be cleaned.

The invention according to claim 6 provides the cleaning apparatus according to claim 1, 2, 3, 4 or 5 , wherein the surface to be cleaned is a porous chuck table used in a semiconductor manufacturing process. .

According to this configuration, it can be applied as a cleaning apparatus for cleaning the holding surface of a porous chuck table that sucks and holds a semiconductor wafer, for example, in a semiconductor manufacturing process.

According to the invention, the spray containing water spray, mist, etc., which is ejected from the ejection port of the cleaning nozzle and bounces off the surface to be cleaned, is applied to the bundled brush element of the brush head arranged around the outer periphery of the ejection port of the cleaning nozzle. It can be dripped into the brush head and prevented from splashing in unexpected places. Moreover, since the brush head provided with the bound brush element is used, the structure is simplified, and the cost and size can be reduced.

1 is a configuration layout diagram of main parts of a porous chuck table cleaning unit that can be used in a semiconductor manufacturing process and that includes the cleaning apparatus of the present invention; FIG. FIG. 2 is a schematic cross-sectional view of the porous chuck table cleaning unit shown as a cross section at a portion corresponding to line AA of FIG. 1; FIG. 3 is an enlarged sectional view of the cleaning device shown in FIG. 2; FIG. 4 is a bottom view of the essential parts of the cleaning device as seen from the direction of arrows BB in FIG. 3;

In order to achieve the object of the present invention, it is possible to perform cleaning without spraying due to rising spray during cleaning, and to provide a cleaning apparatus that is simple in structure, low in cost, and small in size. 1. A cleaning apparatus for cleaning the surface to be cleaned by ejecting a cleaning fluid from an ejection port of a cleaning nozzle toward the surface to be cleaned, the cleaning device having a brush protruding toward the surface to be cleaned. This is achieved by providing a brush head mounted on the nozzle, and arranging a plurality of brushes on the outer circumference of the ejection port at substantially equal intervals.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments for carrying out the present invention will be described in detail based on the accompanying drawings. In addition, in the following description, the same reference numerals are given to the same elements throughout the description of the embodiment. In the following description, expressions indicating directions such as up, down, left, and right are not absolute, and are appropriate when each part of the cleaning apparatus of the present invention is drawn. If it changes, it should be interpreted by changing it according to the change of posture.

FIG. 1 shows the arrangement of essential parts of a porous chuck table cleaning unit 10 that can be used in a semiconductor manufacturing process and is equipped with a cleaning device 31 according to the present invention, and FIG. 2 is a schematic cross-sectional view of the porous chuck table cleaning unit 10 shown as .

1 and 2, the porous chuck table cleaning unit 10 includes a disk-shaped porous chuck table 11 that rotates horizontally when driven by a motor (not shown), and a circular porous chuck table 11 that rotates horizontally when driven by a motor (not shown). A plate-like chuck cleaning grindstone member 12 and a cleaning device 13 for cleaning the top of the porous chuck table 11 are provided.

The porous chuck table 11 is incorporated in, for example, a dicing saw used in a semiconductor manufacturing process. 11B. The porous chuck 11B is made of a porous material, and a negative pressure is applied from the back side to the front side (wafer chucking surface) through the rotary table 11A. W2) can be held by adsorption. The wafer chucking surface of the porous chuck 11B is required to have high flatness because the dicing saw cuts the wafer with a width of about 10 μm to 20 μm.

The chuck cleaning grindstone member 12 has a chuck cleaning grindstone 12a on the lower surface facing the wafer adsorption surface of the porous chuck 11B, and is rotatably attached to the unit main body 10A via a support shaft . The support shaft 14 is connected to the rotating shaft of the motor (not shown) arranged in the unit main body 10A. That is, the chuck cleaning grindstone member 12 is connected to the motor via a support shaft 14 and rotates by receiving the rotation of the motor. While rotating, the chuck cleaning grindstone 12a is brought into contact with the wafer adsorption surface of the porous chuck 11B, and the wafer adsorption surface is polished by the chuck cleaning grindstone 12a to obtain flatness.

The cleaning device 13 is attached to the unit main body 10A via a support arm 21, and moves integrally with the unit main body 10A while spraying a cleaning fluid to remove dust adhering to the wafer adsorption surface of the porous chuck 11B. When the wafer is adsorbed and held on the wafer adsorption surface, dust attached to the surface of the wafer adsorbed and held on the wafer adsorption surface can be removed with the cleaning fluid.

The cleaning device 13 in FIG. 1 indicates two cleaning devices 13, 13 (W1) and 13 (W2). Of these two cleaning apparatuses 13 (W1) and 13 (W2), for example, the cleaning apparatus 13 (W1) is a cleaning apparatus for a 12-inch wafer W1, and the cleaning apparatus 13 (W2) is a cleaning apparatus for an 8-inch wafer W2. Corresponding cleaning equipment. These two cleaning apparatuses 13 (W1) and 13 (W2) always perform cleaning operations during cleaning regardless of the wafers W1 and W2.

3 and 4 are diagrams for explaining the configuration of the cleaning device 13. FIG. 3 is an enlarged cross-sectional view of the cleaning device 13 shown in FIG. 2, and FIG. FIG. 3 is a bottom view of the essential parts of the cleaning device 13 as seen;

3 and 4, the cleaning apparatus 13 has a cleaning nozzle 15 for cleaning the surface of the wafer after cutting or the suction surface of the porous chuck 11B (hereinafter collectively referred to as the "surface to be cleaned"). A brush head 16 , a coil spring 17 as a spring member, and a head holder 18 are attached to the cleaning nozzle 15 .

The cleaning nozzle 15 is an ejection port for ejecting a mixed fluid of cleaning water such as pure water pressurized to about 0.2 MPa and air pressurized to about 0.15 MPa toward the surface to be cleaned. 15a. Further, the lower end side provided with the ejection port 15a is formed in a cylindrical shape. The cleaning nozzle 15 mixes the cleaning water injected from the cleaning water injection port 15b and the air injected from the air injection port 15c into a mixed fluid, and jets this mixed fluid from the jetting port 15a. there is

The brush head 16 has a head body 19 and a brush 20 attached to the head body 19 .

The head main body 19 is attached to the outer periphery of the lower end portion 15A of the cleaning nozzle 15 which is formed in a columnar tubular shape. A lower end portion 15A of the cleaning nozzle 15 is inserted into the head main body 19 from the upper end opening side so as to be vertically slidable. As a result, the head body 19 is attached to the lower end portion 15A of the cleaning nozzle 15 so as to surround the outer periphery of the ejection port 15a. A brush 20 is attached to the lower end surface 19 d of the head body 19 .

The head holder 18 is a cylindrical member that is open at both ends. The head holder 18 has an upper end portion 18a fixed to the upper outer peripheral portion of the cleaning nozzle 15 via a support arm 21 and a fixing bolt 22, and a lower end portion slidably engaged with an upper outer peripheral portion 19a of the head body 19. there is A locking stepped portion 19c is formed at the upper end of the upper outer peripheral portion 19a of the head body 19. As shown in FIG. The engaging stepped portion 19c and the lower end portion 18b of the head holder 18 restrict downward movement of the head body 19 relative to the cleaning nozzle 15 (in the direction of the surface to be cleaned).

A coil spring 17 as a spring member is arranged on the outer circumference of the lower end portion 15A of the cleaning nozzle 15 and is arranged in a compressed state between the cleaning nozzle 15 and the upper end of the head body 19, and in this compressed state. , the head body 19 is always spring-biased downward (in the direction of the surface to be cleaned). Therefore, the head holder 18 is normally held by the biasing force of the coil spring 17 to the position where the engagement stepped portion 19c of the head body 19 and the lower end portion 18b of the head holder 18 are engaged. ing.

The brush 20 is made of a plastic material such as polyvinyl chloride (PVC), and is formed by bundling a plurality of filamentous brush elements having a wire diameter of about 0.16 mm into a substantially cylindrical rod shape. The brush 20 is press-fitted into a mounting hole 19b formed in the lower surface of the head body 19, and then fixed by bonding or the like.

As shown in FIG. 4, a plurality of mounting holes 19b formed in the lower surface of the head body 19 are formed at approximately equal intervals on the inner circumference drawn around the ejection port 15a of the cleaning nozzle 15. It consists of a hole 19b1 and a plurality of mounting holes 19b2 formed at substantially equal intervals on the outer circumference drawn centering on the ejection port 15a of the cleaning nozzle 15 as well. In the embodiment, the mounting hole 19b1 on the inner circumference and the mounting hole 19b2 on the outer circumference are arranged so that each mounting hole 19b2 on the outer circumference in the radial direction of the washing nozzle 15 corresponds to each mounting hole 19b2 on the inner circumference. They are respectively arranged between the holes 19b1. In addition, brushes 20 formed in the shape of cylindrical rods are attached to the attachment hole 19b1 on the inner circumference and the attachment hole 19b2 on the outer circumference in a state of protruding downward (in the direction of the surface to be cleaned). .

Therefore, in the brush head 16 in which the brushes 20 are attached to the lower end surface 19d of the head body 19 in this manner, the brushes 20 of the outer brush row are positioned between the brushes 20 of the inner brush row. . When all of the brushes 20 are viewed from the inside of the brush head 16, the brushes 20 are continuously connected to each other on concentric circles and have a circular brush 20 wall. However, when viewed from below in a plan view, gaps S are provided between the brushes 20 as shown in FIG. 4, and air can be discharged outside through the gaps S. An arrow indicated by reference numeral 100 in FIG. 4 indicates an example of the flow of the discharged air.

When the surface to be cleaned of the porous chuck table 11 is cleaned using the cleaning device 13 having the brush head 16 formed in this way, the cleaning device 13 is lowered and the rotating porous chuck table 11 is cleaned. A brush 20 is brought into contact with the surface. At this time, the excessive pressing force is removed by compressing the coil spring 17 and releasing the brush head 16 upward. The coil spring 17 may not necessarily be provided, and the brush 20 may be pressed against the brush head 16 by its own weight. Simultaneously with the contact, a mixed fluid of cleansing water such as pure water pressurized to about 0.2 MPa and air pressurized to about 0.15 MPa is made porous from the ejection port 15a of the cleansing nozzle 15. Cleaning is started by jetting toward the surface to be cleaned of the chuck table 11 .

When the mixed fluid is jetted from the ejection port 15a of the cleaning nozzle 15, the mixed fluid hits the surface to be cleaned and rebounds to form a spray of water spray or mist. Then, this spray hits the brush 20 of the brush head 16 which is arranged in a wall shape surrounding the outer circumference of the ejection port 15a of the washing nozzle 15, drops down inside the brush head 16, and scatters to an unexpected place. is prevented. On the other hand, air is discharged to the outside through gaps S between the brushes 20 as shown in FIG.

Therefore, the dust on the surface to be cleaned is removed by high-pressure cleaning using this cleaning device 13 . Moreover, in the case of the porous chuck 11B, dirt inside the pores can be removed at the same time.

In addition, since the cleaning device 13 uses the brush head 16 provided with the brush 20, the structure is simplified, and the cost and size can be reduced.

It should be noted that the present invention can be modified in various ways without departing from the spirit of the present invention, and the present invention naturally extends to such modifications.

10 porous chuck table cleaning unit 10A unit main body 11 porous chuck table 11A rotary table 11B porous chuck 12 chuck cleaning grindstone member 12a chuck cleaning grindstone 13 cleaning device 14 support shaft 15 cleaning nozzle 15A lower end 15a ejection port 15b cleaning water 15c air inlet 16 brush head 17 coil spring (spring member)
18 Head holder 18a Upper end 18b Lower end 19 Head body 19a Upper outer peripheral portion 19b Mounting hole 19c Locking stepped portion 19d Lower end surface 19b1 Mounting hole 19b2 on the inner circumference Mounting hole 19c on the outer circumference Locking stepped portion 20 Brush 21 Support arm 100 Air flow

Claims (6)

A cleaning apparatus for cleaning a surface to be cleaned by injecting a cleaning fluid from an ejection port of a cleaning nozzle toward the surface to be cleaned,
a brush head having a brush protruding toward the surface to be cleaned and mounted on the cleaning nozzle;
a plurality of the brushes arranged at substantially equal intervals on the outer periphery of the ejection port when viewed from the bottom surface, and dropping droplets of the spray of the cleaning fluid generated by rebounding from the surface to be cleaned ;
The brush head has an inner brush row formed by arranging the brushes around the nozzle, and an outer brush row formed by arranging the brushes outside the inner brush row,
The brushes of the outer brush row are positioned between the brushes of the inner brush row in the radial direction of the cleaning nozzle, and the brushes of the outer brush row and the brushes of the inner brush row are positioned between the brushes of the inner brush row. are radially arranged from the center without any gaps . 2. A cleaning apparatus according to claim 1, wherein said brush is formed by bundling a plurality of thread-like brush elements. 3. The cleaning apparatus according to claim 1, wherein the brush head is reciprocally slidable with respect to the cleaning nozzle in a central axis direction of the cleaning nozzle. 4. The cleaning apparatus according to claim 3 , further comprising a spring member between said brush head and said cleaning nozzle, which biases and protrudes said brush head toward said surface to be cleaned. 5. A cleaning device according to claim 2, 3 or 4 , wherein said brush element is made of plastic material. 6. A cleaning apparatus according to claim 1, wherein said surface to be cleaned is a porous chuck table used in a semiconductor manufacturing process.

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