Structure of inner wall surface of partition wall, and processing device including the same

Abstract

To propose a novel technique for making it difficult for a scattered matter such as a grinding chip to adhere.SOLUTION: There is provided a structure of an inner wall surface of a partition wall that forms a processing chamber in which a workpiece is arranged inside, a water-repellent surface formed by arranging fine particles being provided on the inner wall surface. A processing device includes a processing chamber cover, a chuck table for holding a workpiece, and a processing unit having a spindle and processing the workpiece held by the chuck table with a processing tool mounted on the spindle. The partition wall covers at least portions of the chuck table and the processing unit.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a partition structure for forming a closed space such as a processing chamber for a workpiece. [Background technology]

[0002] Wafers with multiple IC, LSI, and other devices formed on their surface are ground to a specified thickness on the backside, and then cut into individual devices using a cutting machine for use in electrical equipment such as mobile phones and personal computers.

[0003] For example, as disclosed in Patent Document 1, the grinding process for grinding the back surface of a wafer uses a known grinding device, and a grinding wheel is attached to the spindle of the grinding device to process the wafer to a predetermined thickness through rough grinding and finish grinding.

[0004] Specifically, a grinding wheel is attached to the tip of the spindle of the grinding device, multiple grinding stones arranged on the free end surface of the grinding wheel are brought into contact with the back surface of the wafer, the chuck table holding the grinding wheel and the wafer is rotated, and grinding is performed while the grinding wheel is fed.

[0005] The grinding machine described above is provided with a machining chamber cover that covers the tip of the spindle and the chuck table to define the machining chamber, so that scattered objects such as grinding water containing grinding chips generated during machining are not scattered outside the grinding machine.

[0006] However, if the scattered particles adhere to and accumulate on the top plate or side walls of the processing chamber cover, there is a concern that the particles may fall onto the entire surface of the wafer, adversely affecting processes subsequent to the grinding process.

[0007] Therefore, as shown in Patent Document 2, the applicant has developed and filed a patent application for a technology for jetting a fluid to clean deposits that have adhered to and accumulated on the top plate and side walls of a processing chamber cover. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-288881 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-247272 Summary of the Invention [Problem to be solved by the invention]

[0009] However, the technique disclosed in Patent Document 2 has the problem that it is difficult to spread the fluid over the entire top plate and side walls of the processing chamber cover, making it difficult to completely remove deposits by cleaning.

[0010] Therefore, we discovered that by making it difficult for flying debris such as grinding water containing grinding chips to adhere in the first place, and preventing them from accumulating as adhesions, we can eliminate the problem of adhesions falling onto the surface of the workpiece and causing contamination.

[0011] In view of the above problems, the present invention proposes a new technique for making it difficult for flying matter such as grinding chips to adhere. [Means for solving the problem]

[0012] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0013] According to one aspect of the present invention, the inner wall surface of a partition that defines a processing chamber in which a workpiece is placed is structured such that a water-repellent surface formed by arranging fine particles on the inner wall surface is formed on the inner wall surface.

[0014] According to one embodiment of the present invention, the average particle size of the fine particles is 5 μm or more and 20 μm or less, and the sphericity of the particles is 0.7 or more.

[0015] According to one aspect of the present invention, the fine particles are made of a hydrophobic resin or an inorganic material.

[0016] According to one aspect of the present invention, there is provided a processing device having a processing chamber cover having a wall structure, a chuck table for holding a workpiece, and a processing unit having a spindle and processing the workpiece held on the chuck table with a processing tool attached to the spindle, wherein a partition covers at least a portion of the chuck table and the processing unit. [Effects of the Invention]

[0017] The present invention provides the following effects. That is, according to one aspect of the present invention, the formation of a water-repellent surface on the inner wall surface prevents scattered matter, such as grinding water containing grinding chips or grinding water in a mist state, from adhering to the inner wall surface, thereby preventing the scattered matter from accumulating on the inner wall surface and preventing the accumulated scattered matter from falling onto the surface of the workpiece and causing contamination. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a partially exploded perspective view showing an external appearance of a grinding device according to an embodiment. [Figure 2] 1 is an external perspective view showing a grinding device according to an embodiment; [Figure 3] FIG. 2 is a diagram showing an example of the configuration of a grinding unit. [Figure 4] FIG. 4 is a diagram showing an example of the configuration of a processing chamber cover. [Figure 5] 1A is a diagram showing an example of the configuration of a water-repellent layer, and FIG. 1B is a diagram showing another example of the configuration of a water-repellent layer. [Figure 6] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by a person skilled in the art and those that are substantially the same. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made within the scope of the gist of the present invention.

[0020] FIG. 1 shows a grinding apparatus 1, which is an example of an apparatus for implementing the present invention. The grinding apparatus 1 is an apparatus for grinding a workpiece W to a predetermined thickness. Here, the workpiece W to be processed is, for example, a disk-shaped semiconductor wafer or an optical device wafer made of a base material such as silicon, sapphire, or gallium. The workpiece W is partitioned into multiple regions by planned division lines called streets formed in a grid pattern on the surface, and devices are formed in these partitioned regions. A protective tape is attached to the surface of the workpiece W, and the protective tape is held on a chuck table 10. The back surface Wb of the workpiece W is then ground to thin it to a predetermined thickness.

[0021] 1 and 2, the grinding apparatus 1 includes a chuck table 10 that holds a workpiece W, first and second grinding means 20a, 20b (corresponding to grinding means) that grind the workpiece W held on the chuck table 10, and a processing chamber cover 30 that serves as a partition wall that separates first and second processing chambers K1, K2 (corresponding to processing chambers). The grinding apparatus 1 also includes a transport means 40, a turntable 50, a cleaning means 60, a control means 70, etc.

[0022] The transport means 40 is used to supply the workpieces W before grinding onto the chuck table 10 and to collect the workpieces W after grinding. The transport means 40 is configured to include an input cassette 46 that accommodates a plurality of workpieces W before grinding, a transport mechanism 42, a temporary placement unit 43, an input arm 44, an output arm 45, and an output cassette 41 that accommodates a plurality of workpieces W after grinding.

[0023] The carry-in cassette 46 and the carry-out cassette 41 have the same configuration and are placed at predetermined positions on the main body 2 of the grinding apparatus 1. The transport mechanism 42 removes the workpieces W from the carry-in cassette 46 one by one and places them on the temporary storage section 43, and stores the workpieces W that have been ground by the first and second grinding means 20a, 20b and cleaned by the cleaning means 60 in the carry-out cassette 41. The carry-in arm 44 and the carry-out arm 45 are transport arms that can, for example, rotate and move up and down. The carry-in arm 44 places the workpieces W on the temporary storage section 43 on the chuck table 10 at the carry-in / out position, and the carry-out arm 45 transports the ground workpieces W on the chuck table 10 at the carry-in / out position to the cleaning means 60. The workpiece W placed on the chuck table 10 is subjected to grinding processing in sequence by the first and second grinding means 20a, 20b, then transported to the cleaning means 60 by the discharge arm 45, cleaned by the cleaning means 60, and then stored in the discharge cassette 41 by the transport mechanism 42.

[0024] The turntable 50 is a disk-shaped table provided on the upper surface of the apparatus main body 2, is provided rotatable around the Z axis, and is rotated at appropriate timing. A plurality of chuck tables 10 are provided on the turntable 50. In this embodiment, three chuck tables 10 are provided on the turntable 50, and are arranged at equal intervals of, for example, 120 degrees.

[0025] The chuck table 10 has a surface 10a on which a workpiece W is placed via a protective tape, and the chuck table 10 holds the workpiece W placed on the surface 10a by suction. The chuck table 10 has a disk shape with the surface 10a made of porous ceramic or the like. The chuck table 10 is connected to a vacuum suction source (not shown) via a vacuum suction path (not shown) and holds the workpiece W placed on the surface 10a by suction. The chuck table 10 is movable by the rotation of the turntable 50, and rotates the suction-held workpiece W around the Z axis. The chuck table 10 loads and unloads the workpiece W at a load / unload position closest to the conveying means 40. As the turntable 50 rotates, the chuck table 10 is moved in order to the load / unload position, rough grinding position, finish grinding position, and load / unload position.

[0026] The first grinding means 20a performs rough grinding on the back surface Wb of the workpiece W before grinding, which is held on the chuck table 10 positioned at the rough grinding position, to thin the workpiece W. The second grinding means 20b performs finish grinding on the back surface Wb of the workpiece W that has been roughly ground and is held on the chuck table 10 positioned at the finish grinding position, to thin the workpiece W. The first and second grinding means 20a, 20b are fed for processing by a processing feed means 21. The processing feed means 21 moves the first and second grinding means 20a, 20b closer to the workpiece W held on the chuck table 10 along the Z-axis direction, thereby feeding the first and second grinding means 20a, 20b for processing. In addition, the processing feed means 21 moves the first and second grinding means 20a, 20b away from the workpiece W held on the chuck table 10 along the Z-axis direction, thereby separating the first and second grinding means 20a, 20b from the workpiece W.

[0027] The thickness of the workpiece W ground by the first grinding means 20a is thicker than the thickness of the workpiece W ground by the second grinding means 20b. Since the first grinding means 20a and the second grinding means 20b have substantially the same configuration, the configuration of the first grinding means 20a will be described below as a representative.

[0028] As shown in Fig. 3, the first grinding means 20a includes a grinding water supply means 22 that supplies grinding water L to the workpiece held on the chuck table 10, and a grinding wheel 23 that rotates at high speed. The grinding wheel 23 includes a flange 25 attached to the tip of a spindle 24, an annular base 27 that is fixed to the flange 25 with bolts 26 or the like and rotated by the spindle 24 around the Z axis at a rotational speed of, for example, 3000 rpm, and a plurality of grinding stones 28 attached to the underside of the annular base 27 in an annular shape at predetermined intervals. As shown in Fig. 4, the grinding stones 28 are pressed against the back surface Wb of the workpiece W held on the chuck table 10, and the annular base 27, i.e., the grinding wheel 23, is rotated around the Z axis to grind the back surface Wb of the workpiece W.

[0029] As shown in FIG. 3, the grinding water supply means 22 includes a grinding water supply source 22a and a grinding water supply passage 22c that connects the grinding water supply source 22a to grinding water jet holes 22b that open on the inner circumferential lower surface of the annular base 27 of the grinding wheel 23. The grinding water supply source 22a supplies grinding water L to the grinding water supply passage 22c at a flow rate of, for example, about 3 L / min. The grinding water jet holes 22b open on the outer edge of the lower surface of the annular base 27, closer to the center of the annular base 27 than the grinding wheel 28. The grinding water jet holes 22b are provided at equal intervals around the circumferential direction on the lower surface of the annular base 27. The grinding water supply passage 22c passes through the center of the spindle 24, extends from the center of the flange 25 to the outer periphery of the annular base 27, and is connected to the grinding water jet holes 22b. Further, on the lower surface of the annular base 27, an inclined surface 22d is formed which is inclined from the grinding water ejection holes 22b toward the outer periphery of the annular base 27.

[0030] As shown in Figure 4, the first and second grinding means 20a, 20b rotate the grinding wheel 23 around the Z axis while the grinding water supply means 22 sprays grinding water L from the grinding water outlet 22b, and are fed by the processing feed means 21, and grind the workpiece W by pressing the grinding stone 28 against the back surface Wb of the workpiece W held on the chuck table 10.

[0031] 1, 2, and 4, the machining chamber cover 30 has through holes 31 through which the spindles 24 (FIG. 4) of the first and second grinding means 20a, 20b pass, and covers the chuck table 10 positioned at the rough grinding position and the finish grinding position, and the grinding wheels 23 of the first and second grinding means 20a, 20b. The machining chamber cover 30 has a partition wall 32 (FIG. 1) that separates the first and second grinding means 20a, 20b, and defines the first and second machining chambers K1, K2.

[0032] The first and second processing chambers K1, K2 are spaces inside the processing chamber cover 30 and are separated by a partition wall 32 (FIG. 1). The first processing chamber K1 accommodates the chuck table 10 positioned at the rough grinding position and the grinding wheel 23 of the first grinding means 20a, and the second processing chamber K2 accommodates the chuck table 10 positioned at the finish grinding position and the grinding wheel 23 of the second grinding means 20b.

[0033] 4, the machining chamber cover 30 prevents scattering matter H, such as grinding water containing grinding chips generated by the first and second grinding means 20a, 20b and grinding water in a mist state, from scattering outside the grinding apparatus 1. The first and second machining chambers K1, K2 also allow the chuck table 10 to move between the carry-in / out position, the rough grinding position, and the finish grinding position. The scattering matter H scattered inside the first and second machining chambers K1, K2 is discharged outside the grinding apparatus 1 through a drainage port (not shown).

[0034] 1, the processing chamber cover 30 is provided with a door 33 that can open and close a maintenance opening 34 provided on the top surface of the first and second processing chambers K1 and K2. The door 33 opens the opening 34 in order to replace the grinding wheel 23.

[0035] 1, the control means 70 controls each of the above-mentioned components constituting the grinding apparatus 1, causing the grinding apparatus 1 to perform a processing operation on the workpiece W. The control means 70 is mainly composed of an arithmetic processing unit constituted by a CPU or the like, and a microprocessor (not shown) equipped with a ROM, RAM, etc., and is connected to a display means (not shown) that displays the status of the processing operation, an operation means (not shown) that an operator uses to register processing content information, etc.

[0036] Next, the structure of the inner wall surface of the processing chamber cover according to the present invention will be described. The inner wall surfaces 35a and 35b of the processing chamber cover 30 shown in FIG. 4 are formed with water-repellent surfaces on which fine particles are arranged.

[0037] 4, the processing chamber cover 30 has a water-repellent surface formed on the inner wall surface 35a of the top plate 30a and the inner wall surface 35a of the side wall 30b. It is preferable that the water-repellent surfaces are also formed on the inner wall surfaces of the partition wall 32, door 33, and through-hole 31 shown in FIG.

[0038] Figure 5(A) shows an example of the configuration of a water-repellent surface 36 formed on the inner wall surface 35a of the top plate 30a, and the water-repellent surface 36 is configured with a sheet 37 and fine particles 38 arranged on one surface of the sheet 37.

[0039] The sheet 37 is, for example, a resin film, and one surface thereof functions as an adhesive surface 37a that is attached to the inner wall surface 35a of the top panel 30a. The adhesive surface 37a has an adhesive layer so that it is directly attached to the inner wall surface 35a, or it may be attached to the inner wall surface 35a with a separate adhesive.

[0040] The other surface of the sheet 37 is configured as a particle surface 37b for arranging the particles 38. The particles 38 are arranged on this particle surface 37b.

[0041] The fine particles 38 can be arranged on the fine particle surface 37b by, for example, dispersing the fine particles in a solvent and spraying the solvent onto the fine particle surface 37b with a spray or the like. For example, a sheet 37 having the fine particles 38 arranged on the fine particle surface 37b can be prepared in advance, and the sheet 37 can be attached to the inner wall surface 35a of the top plate 30a. Alternatively, the sheet 37 can be attached to the inner wall surface 35a of the top plate 30a, and then the fine particles 38 can be arranged on the fine particle surface 37b.

[0042] As shown in Figure 5(A), the particles 38 may be arranged evenly in one layer, or may be arranged in multiple layers such as two layers, as long as the outermost surface has unevenness formed by the surface of the particles 38.

[0043] As shown in FIG. 5B, the water-repellent surface 36A may be formed by disposing the fine particles 38 on the surface 37b of the inner wall surface 35a of the top plate 30a by spraying the fine particles directly onto the surface 37b.

[0044] The average particle size of the fine particles 38 is selected from the range of, for example, 5 μm or more and 20 μm or less.

[0045] Particle diameters are defined by known methods such as geometric diameter, equivalent diameter, etc. Geometric diameters include Feret diameter, maximum diameter in a certain direction (i.e., Krummbein diameter), Martin diameter, sieve diameter, etc. Equivalent diameters include diameter equivalent to a circle with a projected area (i.e., Heywood diameter), diameter equivalent to a sphere with an equal surface area, diameter equivalent to a sphere with an equal volume, Stokes diameter, light scattering diameter, etc.

[0046] The sphericity of the fine particles 38 is selected from the range of, for example, 0.7 or more.

[0047] The sphericity is defined, for example, by observing particles at 1000x magnification using a scanning electron microscope, measuring the minor and major axes of 30 randomly selected particles, calculating the minor axis / major axis ratio for each particle, and averaging the values ​​for the 30 particles. For example, if the ratio of the minor axis to the major axis is 1:1, the sphericity is 1.0, and if the ratio of the minor axis to the major axis is 0.7:1, the sphericity is 0.7.

[0048] The fine particles 38 are, for example, a hydrophobic resin or an inorganic material. An example of a hydrophobic resin is commercially available silicone powder (silicone resin: a resin compound refined by chemically reacting silicon (Si)) (for example, product name: KMP-601 manufactured by Shin-Etsu Chemical Co., Ltd.). An example of an inorganic material is silicon (Si) or glass (glass beads). Hydrophobicity refers to a property of having a weak affinity for water, not absorbing water, and repelling water, in other words, exhibiting water repellency.

[0049] As shown in FIG. 6, water repellency refers to the property of a surface to repel water (also known as wettability). Ideally, it is preferable to configure the water repellent surface 36 so that, for example, when a water droplet M is formed on the water repellent surface 36, the contact angle θ is 120 degrees to 150 degrees.

[0050] Regarding the contact angle θ in the example of Figure 6, it was confirmed that when a water-repellent surface was formed using commercially available silicone powder (manufactured by Shin-Etsu Chemical Co., Ltd.: product name: KMP-601) as the fine particles 38 and pure water was used as the water droplets M, the contact angle θ was 140 degrees. Note that when a water-repellent surface was not formed under the same conditions, the contact angle θ was confirmed to be 75 degrees.

[0051] Furthermore, when the sliding angle (angle of inclination of the surface) at which the water droplet M slides down when the surface is tilted was confirmed using the same microparticles 38 and water droplet M used in the investigation of the contact angle θ, it was confirmed that the water droplet M slides down at 41 degrees. Furthermore, when a water-repellent surface is not formed under the same conditions, the sliding angle is found to be 90 degrees or more (the water droplet M does not slide down even when the surface is tilted to 90 degrees (vertical)).

[0052] The structure of the inner wall surface described above is applied to the processing chamber cover 30 shown in FIGS. That is, it is a processing device (grinding device 1) having a processing chamber cover 30 which serves as a partition, a chuck table 10 which holds the workpiece, and a processing unit (grinding wheel 23) which has a spindle 24 and processes the workpiece W held on the chuck table 10 with a processing tool (grinding wheel 28) attached to the spindle 24, and the processing chamber cover 30 is designed to cover at least a portion of the chuck table 10 and the processing unit (grinding wheel 23).

[0053] 4, the water-repellent surface 36 formed on the inner wall surfaces 35a, 35b prevents scattered matter H, such as grinding water containing grinding chips or grinding water in a mist state, from adhering to the inner wall surfaces 35a, 35b. This prevents the scattered matter H from accumulating on the inner wall surfaces 35a, 35b, and prevents the accumulated scattered matter H from falling onto the surface of the workpiece and causing contamination.

[0054] Furthermore, the formation of the water-repellent surface is not limited to the inner wall surfaces 35a, 35b of the processing chamber cover 30 as described above, but may also be formed on, for example, the inner wall surfaces or covers that serve as partitions that define the cleaning space of the cleaning means 60 shown in Figure 1.

[0055] Furthermore, the processing device may be a grinding device shown in Figures 1 and 2, a cutting device that cuts and dices the wafer along the planned dividing lines with a cutting blade, a laser processing device that dices by laser processing, or the like. [Explanation of symbols]

[0056] 1 Grinding equipment 2. Device body 10 Chuck table 20a Grinding means 20b Grinding means 21 Processing feed means 23 Grinding Wheel 24 spindles 27 Circular Base 28 Grinding Wheel 30 Processing chamber cover 30a baking sheet 30b side wall 31 Through hole 32 Partition Wall 33 Door 34 Aperture 35a Inner wall 35a Inner wall 36 Water-repellent surface 37 seats 37a Adhesive side 37b Fine particle surface 38 Fine particles 60 Cleaning Methods H Flying objects K1 processing room K2 processing room L Grinding water T protective tape W Workpiece Wb back side

Claims

1. A structure of an inner wall surface of a partition wall defining a processing chamber in which a workpiece is placed, A water-repellent surface is formed on the inner wall surface by disposing fine particles thereon. Structure of the inner wall surface of the bulkhead.

2. 2. The structure of the inner wall surface of the partition wall according to claim 1, wherein the fine particles have an average particle diameter of 5 μm or more and 20 μm or less, and a sphericity of the particles of 0.7 or more.

3. The microparticles are made of a hydrophobic resin or an inorganic material. The structure of the inner wall surface of the partition wall according to claim 2 .

4. a processing chamber cover having the inner wall surface structure of the partition wall according to any one of claims 1 to 3; a chuck table for holding the workpiece; a processing unit having a spindle and processing the workpiece held on the chuck table with a processing tool attached to the spindle, The partition wall covers at least the chuck table and a part of the processing unit.

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