Dressing tool, holding table, processing device, and dressing method

Abstract

To provide a new technique for suppressing occurrence of warpage of a dressing tool when a processing groove is formed in the dressing tool.SOLUTION: A dressing tool for dressing a blade of a cutting blade includes: a dressing layer which is composed of at least abrasive grains and a binding material fixing the abrasive grains; and a magnetic layer which is provided on one surface side of the dressing layer, and has magnetism.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a technique for dressing (sharpening) the cutting edge of a cutting blade. [Background technology]

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

[0003] Furthermore, packaged devices such as CSP (Chip Size Package) and QFN (Quad Flat Non-Leaded Package) and ceramic capacitors (hereinafter simply referred to as workpieces) are also separated into individual devices by cutting equipment and used in electrical equipment, etc.

[0004] In the step of dividing the substrate into individual devices, a cutting blade is attached to a cutting device (hereinafter referred to as a processing device) and the substrate is divided into individual devices by cutting.

[0005] The cutting blades are selected from various cutting blades such as electroformed blades made of nickel-plated diamond abrasive grains, resin blades made of resin-bonded or metal-bonded diamond abrasive grains, and metal blades, depending on the characteristics of the workpiece.

[0006] Here, for example, Patent Document 1 discloses a method of performing a dressing process in which, after a cutting blade is attached to a processing device, a plate-shaped dressing tool is used to cut the cutting blade into the dressing tool in order to make the cutting blade perfectly round and to protrude (sharpen) the abrasive grains before actual processing.

[0007] The dressing tool is suction-held on a holding table (also called a sub-chuck table) provided near a chuck table that suction-holds a workpiece of a processing device. The dressing tool is used in first and second directions that are orthogonal in plan view, starting from one end side in the first direction, and a machined groove is formed in the surface of the dressing tool in the second direction by each dressing process. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2000-049120 A Summary of the Invention [Problem to be solved by the invention]

[0009] When a plurality of grooves extending in the second direction are formed in the dressing tool so as to be parallel to the first direction, there is a concern that warping may occur in the direction in which the surface side of the dressing tool is recessed.

[0010] If significant warping occurs, ideal cutting depth will not be achieved, raising concerns that the cutting blade edge may be damaged. Furthermore, warping can cause the back surface of the dressing tool to float above the suction holding surface of the sub-chuck table, leading to concerns that negative pressure may leak and insufficient holding force may be secured. If the holding force weakens, there is a concern that the dressing tool may shift, damaging the cutting blade edge.

[0011] In view of the above problems, the present invention proposes a novel technique for suppressing the occurrence of warpage of a dressing tool when a machined groove is formed in the dressing tool. [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, a dressing tool for dressing the edge of a cutting blade is provided, which has a dressing layer composed at least of abrasive grains and a binder for fixing the abrasive grains, and a magnetic layer having magnetic properties and provided on one side of the dressing layer.

[0014] According to one aspect of the present invention, a holding table is provided having a holding surface for holding a dressing tool, the holding table being equipped with a magnet that generates a magnetic force that attracts the magnetic layer, and the holding table holds the magnetic layer side of the dressing tool so as to attract the magnetic layer side toward the holding surface when the magnetic layer side of the dressing tool is placed on the holding surface.

[0015] According to one aspect of the present invention, the magnet is an electromagnet, and generates the magnetic force when energized when the dressing tool is held by the holding table.

[0016] According to one aspect of the present invention, the magnet is arranged to be movable between a holding position, which is a position where a magnetic force for holding is generated between the magnet and the dressing tool, and a retracted position, which is a position farther away from the dressing tool than the holding position.

[0017] According to one aspect of the present invention, the holding surface further includes a suction portion for holding the dressing tool by suction.

[0018] According to another aspect of the present invention, a processing apparatus includes a holding table.

[0019] Furthermore, according to one aspect of the present invention, there is provided a method for dressing a cutting blade of a processing device, which involves cutting into the dressing layer of the dressing tool held on the holding table and the magnetic layer, and fully cutting and dressing the dressing layer. [Effects of the Invention]

[0020] The present invention provides the following effects. In other words, according to one aspect of the present invention, the dressing tool is attracted downward by a magnet, thereby suppressing the occurrence of warping, achieving ideal cutting, and enabling ideal trimming (sharpening).

[0021] Furthermore, according to one aspect of the present invention, the dressing tool can be easily removed. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view schematically showing an example of the configuration of a cutting device equipped with a holding table according to the present invention; [Figure 2] 1A is a perspective view of a dressing tool according to the present invention, and FIG. 1B is a side view of the same. [Figure 3] FIG. 4 is a diagram showing the arrangement of a holding table. [Figure 4] 1A is a plan view showing the holding surface of the holding table, and FIG. 1B is a plan view of the holding table with a magnet attached. [Figure 5] 1A is a side cross-sectional view showing the internal structure of the holding table, and FIG. 1B is a diagram illustrating the state in which the magnet is positioned at the retracted position. [Figure 6] 10A and 10B are diagrams illustrating warpage of a dressing tool. [Figure 7] FIG. 10 is a diagram illustrating the implementation of trimming. [Figure 8] 1A is a diagram illustrating an example of forming a machined groove, and FIG. 1B is a diagram illustrating an example of cutting a dressing layer. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing a typical configuration example of a cutting device equipped with a holding table (sub-chuck table) of this embodiment. As shown in Fig. 1, the cutting device 2 is equipped with a base 4 that supports each component.

[0024] A rectangular opening 4a is formed in the front corner of the base 4, and a cassette mounting table 6 is installed in this opening 4a so that it can move up and down. A rectangular parallelepiped cassette 8 that stores multiple wafers is placed on the upper surface of the cassette mounting table 6. For ease of explanation, only the outline of the cassette 8 is shown in FIG. 1.

[0025] A rectangular opening 4b that is long in the X-axis direction (front-rear direction, processing feed direction) is formed on the side of the cassette mounting table 6. Inside this opening 4b, there are provided an X-axis moving table 10, an X-axis moving mechanism (processing feed means) (not shown) that moves the X-axis moving table 10 in the X-axis direction, and a dustproof and drip-proof cover 12 that covers the X-axis moving mechanism.

[0026] The X-axis movement mechanism is equipped with a pair of X-axis guide rails (not shown) parallel to the X-axis direction, and an X-axis movement table 10 is slidably mounted on the X-axis guide rails. A nut portion (not shown) is provided on the underside of the X-axis movement table 10, and an X-axis ball screw (not shown) parallel to the X-axis guide rails is screwed into this nut portion.

[0027] An X-axis pulse motor (not shown) is connected to one end of the X-axis ball screw. By rotating the X-axis ball screw with the X-axis pulse motor, the X-axis moving table 10 moves in the X-axis direction along the X-axis guide rail.

[0028] A chuck table 14 that suction-holds a workpiece such as a wafer (not shown) is provided in an opening provided in the X-axis moving table 10. This chuck table 14 is connected to a rotation drive source (not shown) such as a motor, and rotates around a rotation axis parallel to the Z-axis direction (up-down direction, vertical direction).

[0029] The surface (upper surface) of the chuck table 14 is a holding surface 14a that holds the workpiece by suction. This holding surface 14a is connected to a suction source (not shown) through a flow path (not shown) formed inside the chuck table 14.

[0030] Two holding tables 16 that hold plate-shaped dressing tools 60 (see FIG. 3, etc.) by suction are arranged near the chuck table 14. The holding tables 16 are also called sub-chuck tables, and will be described in detail later.

[0031] A gate-shaped support structure 20 that supports cutting units (cutting means) 18a, 18b is disposed across the opening 4b on the upper surface of the base 4. Two sets of cutting unit moving mechanisms (indexing feed means) 22 that move the cutting units 18a, 18b in the Y-axis direction (left-right direction, indexing feed direction) and the Z-axis direction are provided on the upper front surface of the support structure 20.

[0032] Each cutting unit movement mechanism 22 has a pair of Y-axis guide rails 24 in common that are arranged in front of the support structure 20 and parallel to the Y-axis direction. A Y-axis movement plate 26 that constitutes each cutting unit movement mechanism 22 is slidably installed on the Y-axis guide rails 24.

[0033] A nut portion (not shown) is provided on the back surface (rear surface) of each Y-axis moving plate 26, and a Y-axis ball screw 28 parallel to the Y-axis guide rail 24 is screwed into this nut portion.

[0034] A Y-axis pulse motor 30 is connected to one end of each Y-axis ball screw 28. When the Y-axis pulse motor 30 rotates the Y-axis ball screw 28, the Y-axis moving plate 26 moves in the Y-axis direction along the Y-axis guide rail 24.

[0035] A pair of Z-axis guide rails 32 parallel to the Z-axis direction are provided on the surface (front surface) of each Y-axis moving plate 26. A Z-axis moving plate 34 is slidably installed on the Z-axis guide rails 32.

[0036] A nut portion (not shown) is provided on the back surface (rear surface) of each Z-axis moving plate 34, and a Z-axis ball screw 36 parallel to the Z-axis guide rail 32 is screwed into this nut portion.

[0037] A Z-axis pulse motor 38 is connected to one end of each Z-axis ball screw 36. When the Z-axis pulse motor 38 rotates the Z-axis ball screw 36, the Z-axis moving plate 34 moves in the Z-axis direction along the Z-axis guide rail 32.

[0038] Cutting units 18a and 18b that cut the workpiece are provided below each Z-axis moving plate 34. Also, a camera (imaging means) 40 that captures an image of the top surface of the workpiece is installed adjacent to cutting unit 18a.

[0039] Each of the cutting units 18a and 18b includes an annular cutting blade 44 attached to one end of a spindle that forms a rotation axis parallel to the Y-axis direction. A rotation drive source (not shown), such as a motor, is connected to the other end of the spindle, and rotates the cutting blade 44 attached to the spindle.

[0040] A circular opening 4c is formed at a position opposite to the opening 4a with respect to the opening 4b. A cleaning mechanism 46 for cleaning the workpiece after cutting is provided inside the opening 4c.

[0041] Next, the dressing tool of this embodiment will be described. 2(A) and 2(B) show one embodiment of the dressing tool 60. As shown in FIG. The dressing tool 60 is a dressing tool for dressing the cutting blade edge, and includes a dressing layer 62 composed at least of abrasive grains and a binder for fixing the abrasive grains, and a magnetic layer 64 provided on one side of the dressing layer 62. The dressing tool 60 is also called a dress board.

[0042] The dressing layer 62 is formed in a plate shape with a thickness of, for example, 0.8 mm to 4.0 mm, and well-known abrasive grains and bonding materials can be used. The dressing layer 62 is used for sharpening the cutting edge of a cutting blade (not shown) by cutting into it. The dressing layer 62 may also be formed as a so-called dummy wafer made of the same material as the semiconductor wafer.

[0043] The magnetic layer 64 is configured in the shape of a plate, for example, with a thickness of 0.4 mm to 1.0 mm, and is made of a metal such as stainless steel, which is primarily composed of iron, and is not particularly limited as long as it is a magnetic material that is attracted to the magnet described below.

[0044] The dressing tool 60 can be integrally constructed, for example, by using the magnetic layer 64 as a substrate and forming the dressing layer 62 on the magnetic layer 64. Alternatively, the dressing tool 60 can be integrally constructed, for example, by bonding the dressing layer 62 and the magnetic layer 64, each made of an independent plate material, with an adhesive.

[0045] The dressing tool 60 may be configured as a rectangular plate as a whole, a square plate, or a long rod.

[0046] FIG. 3 is a diagram showing the arrangement of the holding table 16 having a holding surface 16a for holding the dressing tool 60. As shown in FIG. In this embodiment, two holding tables 16 are arranged on the X-axis moving table 10 and are configured to dress the cutting blades attached to the cutting units 18a and 18b (FIG. 1), respectively. Note that two or more holding tables may be provided.

[0047] The holding table 16 is formed in a substantially rectangular parallelepiped shape. A holding surface 16a for holding the dressing tool 60 is formed on the rectangular surface (upper surface) of the holding table 16.

[0048] As shown in FIG. 4(A), a grid-like suction groove 48 is formed on the holding surface 16a of each holding table 16 to suck the back surface 60b (lower surface) of the dressing tool 60 (FIG. 3). The suction groove 48 includes, for example, a plurality of first suction grooves (vertical grooves) 48a extending in the X-axis direction and a plurality of second suction grooves (horizontal grooves) 48b extending in the Y-axis direction, and is connected to a suction source 53 through a suction path 50 opening in the bottom surface. The pressure in the suction path 50 may be monitored by a pressure measuring device (not shown), so that a malfunction can be detected when the position of the dressing tool 60 is shifted and negative pressure leaks occur.

[0049] Adjacent side surfaces 16b, 16c of the holding table 16 are provided with abutment walls 52a, 52b against which a side surface 60c (FIG. 4(B)) of the dressing tool 60 abuts.

[0050] The height from the holding surface 16a to the upper ends of the abutment walls 52a and 52b is smaller than the thickness of the dressing tool 60. In other words, the height of the upper ends of the abutment walls 52a and 52b is lower than the height of the surface (upper surface) 60a of the dressing tool 60 placed on the holding surface 16a. This prevents interference between the abutment walls 52a and 52b and the cutting edge 44a of the cutting blade 44 when the cutting blade 44 cuts into the surface 60a of the dressing tool 60, as shown in FIG.

[0051] 4(A) and 4(B), the holding surface 16a is formed with magnet accommodating portions 16s for accommodating magnets 17 that generate a magnetic force that attracts the magnetic layer 64 of the dressing tool 60. In this embodiment, two long groove-shaped magnet accommodating portions 16s are formed in the Y-axis direction, and are configured so that long magnets 17 can be accommodated in the magnet accommodating portions 16s.

[0052] As shown in Fig. 4(B), when the long magnet 17 is housed in the magnet housing portion 16s, the upper surface 17a of the magnet 17 is disposed at substantially the same height as the holding surface 16a, as shown in Fig. 5(A). As a result, the upper surface 17a of the magnet 17 comes into contact with the back surface 60b of the dressing tool 60, that is, the magnetic layer 64, and the magnetic layer 64 side is attracted to and held by the holding surface 16a.

[0053] 4(B), the magnets 17 are configured to be arranged over a wide range in the indexing feed direction of the cutting units 18a and 18b (FIG. 1), that is, in the Y-axis direction. This allows the dressing tool 60 to be attracted downward by the magnets 17 over a wide range in the Y-axis direction, thereby preventing the dressing tool 60 from warping.

[0054] In the example of Figure 4(B), the length of the magnet 17 in the Y-axis direction is configured to be shorter than that of the dressing tool 60, but it is also possible to configure them to be approximately the same length and to attract both ends of the dressing tool 60 to the magnet 17.

[0055] 4(B) can be configured with, for example, a permanent magnet, which allows the holding table 16 to be realized with a simple configuration that is highly reliable and has a low probability of failure.

[0056] 4(B) may be configured to be, for example, an electromagnet, which generates a magnetic force when energized when the dressing tool 60 is held by the holding table 16. In this case, wiring (not shown) for energizing the magnet and a control device (not shown) for controlling the on / off of energization are provided.

[0057] If the magnet 17 is an electromagnet, the magnetic force can be released when removing the dressing tool 60 for maintenance, allowing the dressing tool 60 to be easily removed. Furthermore, since the installation work can be performed without being affected by the magnetic force, the positioning work relative to the abutment walls 52a and 52b (FIG. 4(B)) can also be easily performed. Because the dressing tool 60 is plate-shaped and has no protrusions, it is important to make removal and positioning easy and improve workability.

[0058] As shown in Figure 5(A), the magnet 17 may be configured to be movable between a holding position H1, which is a position where a magnetic force for holding is generated between the magnet 17 and the dressing tool 60, and a retracted position H2, which is a position farther away from the dressing tool 60 than the holding position H1, as shown in Figure 5(B).

[0059] Specifically, for example, the magnet 17 is placed at the tip of a rod 72 of an actuator 70 such as an air cylinder, and the position of the magnet 17 is changed by moving the rod 72 back and forth. A vertical hole 16u for passing the rod 72 can be formed in the bottom of the magnet storage section 16s (FIGS. 4(A) and 5(A)).

[0060] As a result, when removing the dressing tool 60 for maintenance, the magnetic force acting on the dressing tool 60 can be released by moving the magnet 17 to the retracted position H2 as shown in Fig. 5(B), and the dressing tool 60 can be easily removed. This configuration is particularly effective when the magnet 17 is a permanent magnet.

[0061] An example of a dressing method in the above configuration will be described. As shown in FIG. 6, when the dressing tool 60 is placed on the holding surface 16a of the holding table 16, the magnetic layer 64 of the dressing tool 60 (the back surface 60b of the dressing tool 60) is attracted to the magnet 17 and held on the holding surface 16a.

[0062] 6, even if a dressing tool 60 having a machined groove 66 formed therein, that is, a dressing tool 60 that has been used partway and warped, is used, the dressing tool 60 is attracted by the magnet 17, and the warping is eliminated. That is, for example, a dressing tool 60 that has warped during use can be installed in a horizontal state with the warping eliminated, just like a new one, and good conditions for dressing can be created.

[0063] Furthermore, suction and holding are simultaneously performed by generating a negative pressure on the holding surface 16a of each holding table 16. Note that, if the dressing tool 60 can be held only by the magnetic force of the magnet 17, suction and holding may be omitted.

[0064] 7, the lower end of the cutting edge 44a of the cutting blade 44 is positioned at the cutting height and rotated in the rotation direction R. Then, the X-axis moving table 10 is moved in the processing feed direction, causing the cutting edge 44a of the cutting blade 44 to cut into the dressing tool 60, thereby performing dressing.

[0065] 8(A), a processing groove 66 is formed in the second direction (X-axis direction), which is the processing feed direction, in the dressing tool 60. Every time dressing is performed, the cutting blade 44 (FIG. 7) is index-fed in the first direction (Y-axis direction), and multiple processing grooves 66 are formed along the first direction (Y-axis direction).

[0066] There is a concern that the dressing tool 60 may warp as multiple machining grooves 66 are formed in this manner, but according to the present invention, the dressing tool 60 is attracted downward by a magnet, thereby suppressing the occurrence of warping, achieving ideal cutting depths, and enabling ideal trimming (sharpening).

[0067] Furthermore, as shown in FIG. 8(B), the dressing tool 60 may cut into the dressing layer 62 and the magnetic layer 64, and the dressing layer 62 may be fully cut to perform dressing.

[0068] This allows the cutting blade to cut deeper to form a deep groove 68, making it possible to dress a wider area of ​​the cutting blade edge. Also, in this case, the magnetic layer 64 remains, so the dressing tool 60 can be held without separation and while suppressing warping. [Explanation of symbols]

[0069] 2 Cutting equipment 14 Chuck table 16 Holding table 16a Holding surface 16u vertical hole 16s Magnet storage section 17 Magnet 17a Top side 18a Cutting unit 44 Cutting Blade 44a blade 60 Dressing Tools 60a surface 60b back side 60c side 62 Dressing layer 64 Magnetic layer 66 Machining groove 70 Actuator 72 Rod H1 holding position H2 Evacuation position

Claims

1. A dressing tool for dressing a cutting blade, a dressing layer comprising at least abrasive grains and a binder for fixing the abrasive grains; a magnetic layer provided on one side of the dressing layer and having magnetic properties; Having a dressing tool.

2. A holding table having a holding surface for holding the dressing tool according to claim 1, a magnet that generates a magnetic force that attracts the magnetic layer; a holding table that holds the magnetic layer side of the dressing tool so as to attract the magnetic layer side to the holding surface, with the magnetic layer side of the dressing tool placed on the holding surface;

3. the magnet is an electromagnet, When the dressing tool is held by the holding table, the magnetic force is generated by energizing the holding table.

3. The holding table according to claim 2.

4. The magnet is a holding position where a magnetic force for holding is generated between the holding position and the dressing tool; a retracted position which is a position farther from the dressing tool than the holding position, 3. The holding table according to claim 2.

5. The holding surface further includes a suction portion for suction-holding the dressing tool.

5. The holding table according to claim 2, wherein the holding table is a holding table having a first end and a second end.

6. A processing device comprising the holding table according to any one of claims 2 to 5.

7. 7. A method for dressing a cutting blade of a processing device according to claim 6, comprising: cutting into the dressing layer and the magnetic layer of the dressing tool held on the holding table; The dressing layer is fully cut and dressed. A dressing method characterized by:

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