JP5410917B2 - Laminated dressing board and dressing method and cutting method using the same - Google Patents

Description

  The present invention relates to a laminated dressing board for conspicuous blades containing abrasive grains, and a dressing method and a cutting method using the same.

  As a method of dividing a workpiece, for example, a semiconductor wafer having a plurality of devices on the surface into individual devices using a cutting apparatus, a step cutting method is employed in which cutting is performed with two types of cutting blades. In the step cut method, as described in Patent Document 1 below, a cutting groove forming blade for forming a cutting groove from the surface of the wafer and a semiconductor wafer for cutting along the cutting groove to divide the semiconductor wafer Cutting is performed with two types of blades, ie, a blade for division. The blade is formed in a disk shape by bonding diamond abrasive grains with electrodeposited nickel, for example. In general, two types of blades used in the step-cut method are cutting groove forming blades made of tough members made of an oxide film formed on the wafer surface or a metal such as an evaluation element (TEG). In the cutting and dividing blades, since the processing objects such as cutting the wafer main body are different, the diamond abrasive grains contained and the content rate are formed in accordance with the respective processing objects.

  As known to those skilled in the art, the blade is used for processing a workpiece after cutting the dressing board and making the abrasive grains protrude from the nickel bond. The dressing board is formed by hardening abrasive grains such as GC (green carbon) and WA (white alundum) with a binder such as resin. Such a dressing board is used by changing a suitable abrasive grain size, resin type, or the like according to the diamond abrasive grains contained in the blade and the content. In addition to the usual method of using a dressing board and making the dressing before processing the workpiece as described above, as described in Patent Document 2 below, dressing is performed adjacent to the outer periphery of the workpiece. A so-called in-line dress is put into practical use, in which a workpiece is cut following or prior to placing a board, cutting a dressing board with a blade, or prior to cutting, and thus alternately performing sharpening and workpiece cutting. ing.

Japanese Patent Laid-Open No. 2003-334751 JP 2004-288916 A

  In the case where the cutting groove forming blade and the dividing blade having different diamond abrasive grain sizes and content rates are conspicuous, two types of dressing boards suitable for each blade are required. Therefore, when cutting by the step cut method, two types of dressing boards must be prepared, and the dressing work must be performed with two dressing boards, and the dressing board is changed during the dressing work. There is a problem that work becomes complicated and efficiency is low. Further, when performing inline dressing, even if two types of dressing boards are separately placed adjacent to the workpiece, the operation of cutting only one dressing board with the blade is extremely complicated.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem is that even when dressing two different types of blades by the step-cut method, two types of dressing boards are prepared separately and are complicated. It is an object of the present invention to provide a new and improved dressing board and a dressing method using the dressing board which can be sharpened with an optimum dressing board for each blade without having to perform a special operation. Another technical problem of the present invention is that a new and improved laminated dressing board capable of dressing two kinds of blades with only an optimum dressing board, respectively, even when performing inline dressing, and cutting using the same Is to provide a method.

According to the present invention, as a dressing board for solving the main technical problem, a first dressing board for conspicuous a first blade containing abrasive grains,
A second layer laminated and secured to the lower surface of the first dressing board for conspicuous a second blade containing abrasive grains different from the first blade and having a thickness smaller than the first blade A dressing board is provided.

  The first blade is a blade for cutting from the exposed surface of the workpiece to form a cutting groove in the workpiece, and the second blade is cut along the cutting groove and A blade for dividing the workpiece is preferred.

  Further, as a dressing method for solving the main technical problem, the laminated dressing board according to any one of the above is used, and the first dressing board in the laminated dressing board is entirely formed with the first blade. A first dressing step that forms a cutting groove in the laminated dressing board, conspicuously the first blade, and exposes the second dressing board to a bottom surface of the cutting groove; After the first dressing step, the second dressing board is formed by cutting the second dressing board along the cutting groove with the second blade and sharpening the second blade. A dressing method using a board is provided.

  Further, as a laminated dressing board that solves the other technical problems in addition to the main technical problems, the thickness of the second dressing board is such that the work piece after the cutting grooves are formed is cut into the workpiece. The thickness of the workpiece cut by the second blade along the groove is the same as the thickness of the workpiece, and the total thickness of the first dressing board and the second dressing board stacked is the thickness of the workpiece. A laminated dressing board that is identical is provided.

  Further, as a cutting method for solving the other technical problems in addition to the main technical problems, the laminated dressing board described above is disposed adjacent to the outer periphery of the workpiece, and the first blade is used. The first dressing board in the laminated dressing board is cut over its entire thickness to form a cutting groove in the laminated dressing board, the first blade is sharpened, and the first dressing board is formed on the bottom surface of the cutting groove. A cutting groove forming step of exposing the second dressing board and subsequently or prior to cutting the workpiece with the first blade to form a cutting groove in the workpiece; and a cutting groove forming step Later, the second dressing board is cut along the cutting groove of the laminated dressing board, the second blade is sharpened and the laminated dressing board is divided. Then, prior to or prior to this, the cutting method comprising the dividing step of cutting the workpiece along the cutting groove of the workpiece with the second blade and dividing the workpiece. Provided.

  In the dressing board and dressing method according to the present invention, even when two types of blades are conspicuous by the step-cut method, two types of dressing boards suitable for each of the two types of blades are laminated. The complexity of the is eliminated, and each blade can be conspicuous effectively. In the cutting method according to the present invention, even when performing inline dressing, the workpiece can be cut while performing inline dressing only with a dressing board suitable for each blade.

The perspective view which shows a to-be-processed object. The perspective view which shows the principal part of a cutting device. The schematic sectional drawing explaining a step cut system. The perspective view which shows the usage condition of one Embodiment of a laminated dressing board. (A) The schematic sectional drawing which shows a 1st dressing process. (B) Schematic sectional view showing a second dressing process. The perspective view which shows the usage condition of other embodiment of a lamination dressing board. (A) The schematic sectional drawing which shows the cutting method using other embodiment of a lamination dressing board. (B) The schematic sectional drawing which shows the cutting method using other embodiment of a lamination dressing board.

  Hereinafter, preferred embodiments of a laminated dressing board of the present invention and a dressing method and a cutting method using the same will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a semiconductor wafer as an example of the workpiece 2. The workpiece 2 is formed of a silicon substrate, and devices 6 such as LSIs are arranged on the surface 2a in a plurality of regions partitioned by division lines 4 formed in a lattice shape. An evaluation element (TEG) for evaluating a plurality of devices 6 is formed on the division line 4 and is covered with a protective film. The semiconductor wafer of the embodiment has a diameter of 8 inches and a thickness of 400 μm. On the other hand, the support frame 8, which can be formed of metal or synthetic resin, has a relatively large circular opening 10 in the center, and the mounting tape 12 extends across the circular opening 10 and is attached to the back surface of the support frame 8. It is worn. The workpiece 2 is positioned in the circular opening 10, and the back surface thereof is attached to the mounting tape 12.

  A main part of a cutting apparatus for cutting the workpiece 2 is shown in FIG. The illustrated embodiment is an opposed two-spindle cutting device in which two cutting means 14a and 14b are arranged on a Y axis so as to face each other in a substantially straight line. See, for example, JP-A-2003-334751 for the overall configuration of the cutting apparatus. As shown in FIG. 2, the cutting device is provided with two opposing cutting means 14a and 14b and a chuck table 16.

  The chuck table 16 is disposed so as to be rotatable about a central axis, and has a chuck plate 18 formed of porous ceramics on the surface. A pipe (not shown) is formed below the chuck plate 18, and the pipe is connected to a vacuum suction source (not shown). The workpiece 2 mounted on the support frame 8 is placed on the chuck plate 18 of the chuck table 16, and the workpiece 2 is sucked and held on the chuck plate 18 when the chuck plate 18 communicates with a vacuum suction source. The A frame clamp (not shown) for placing the support frame 8 on the upper surface is disposed outside the outer periphery of the chuck table 16, and the support frame 8 is placed and gripped on the frame clamp. Further, the chuck table 16 is disposed so as to be movable in the X-axis direction in FIG.

  The two opposing cutting means 14a and 14b are respectively housings 20a and 20b, wheel covers 22a and 22b attached to the front ends of the housings 20a and 20b, and cutting blades 24a and 24b (FIGS. 3, 5, and 7). See also). The cutting blades 24a and 24b are attached to the tips of spindles (not shown) that are rotatably disposed in the housings 20a and 20b. The cutting means 14a and 14b are arranged so as to be individually movable in the Y-axis direction and the Z-axis direction in FIG. The wheel covers 22a and 22b are provided with cutting water supply nozzles 27a and 27b (see FIG. 3) for supplying cutting water for cooling the blades 24a and 24b and removing cutting waste generated during cutting. .

  In order to perform processing by the step cut method, the blade 24a as the first blade is attached to the cutting means 14a, and the blade 24b as the second blade is attached to the cutting means 14b. The blade 24a is a blade for cutting a predetermined depth from the exposed surface 2a of the workpiece 2 to form a cutting groove 36 (see FIG. 3) in the workpiece 2. The blade 24a cuts an evaluation element (TEG) formed of a tough material such as metal on the division line 4 formed on the surface 2a of the workpiece 2. As shown in FIG. 3, the blade 24 b is a blade for cutting up to the adhesive tape 12 and cutting along the cutting groove 36 to divide the workpiece 2. In order to perform the cutting of the workpiece 2 by lowering the blade 24b into the cutting groove 36 formed by the blade 24a, the blade 24b is formed thinner than the blade 24a. In this embodiment, since the workpiece 2 is a silicon substrate semiconductor wafer, it is formed by a disk-shaped electroformed blade in which diamond abrasive grains are bonded with electrodeposited nickel as a blade suitable for processing a semiconductor wafer. Has been. The blade 24a and the blade 24b are formed with abrasive grains having a suitable particle size, a degree of concentration, and the like according to the workpiece.

  Subsequently, an embodiment of the laminated dressing board according to the present invention will be described in detail with reference to FIG. In the embodiment, the laminated dressing board 26 is formed in a square plate shape having a length of 80 mm on one side, for example. A dressing board 28 that is a first dressing board suitable for sharpening the blade 24a and a dressing board 30 that is a second dressing board suitable for sharpening the blade 24b. The dressing board 30 is fixed to the surface. The dressing board 28 has a thickness of 200 μm, for example, and the dressing board 30 has a thickness of 500 μm, for example, and has a total thickness of 700 μm.

  As a manufacturing method of the laminated dressing board 26, first, the raw materials of the dressing board 28 and the dressing board 30 are separately mixed. Each of the dressing boards 28 and 30 mixes resin as a binder and abrasive grains having a predetermined particle size, such as WA (white alundum). For example, the dressing board 28 contains abrasive grains having a particle size of 1 to 1.5 μm, and the dressing board 30 contains abrasive grains having a particle size of 2 to 3 μm. In the embodiment, the raw material for the dressing board 30 having a thickness of 500 μm is pressed at room temperature, the raw material for the dressing board 28 is laminated thereon with a thickness of 200 μm, and the laminated body is heated at the sintering temperature while being pressed. To do. The thickness accuracy of each dressing board is improved by pressing twice, and the laminates are fixed to each other by heat pressing. Next, the bonded laminated body is cut into a predetermined shape (in the embodiment, a square having a side of 80 mm), and the laminated dressing board 26 is formed. Vitrified other than resin can be used as the binder, and GC other than WA can be used as the abrasive.

  Details of the dressing method using the laminated dressing board 26 will be described with reference to FIGS. As shown in FIG. 4, the laminated dressing board 26 is attached to the support frame 32 by sticking the exposed surface of the dressing board 30 to the adhesive surface of the adhesive tape 34 attached to the support frame 32. Installed. After the two types of blades are respectively attached to the cutting means 14a and 14b, the laminated dressing board 26 attached to the support frame 32 via the adhesive tape 34 is sucked and held on the chuck table 16 (see FIG. 2) of the cutting apparatus. Next, rotation of the blades 24a and 24b of the cutting means 14a and 14b is started, and supply of cutting water is started. First, the first dressing process is performed. As shown in FIG. 5 (a), the dressing board 28 in the laminated dressing board 26 is cut over the entire thickness by the blade 24a, and a cutting groove 29 (see FIG. 5 (b)) is formed in the laminated dressing board 26. Form. After the cutting grooves 29 are formed as necessary, the cutting means 14a is index-moved, the cutting grooves 29 are formed again, and a plurality of cutting grooves 29 are formed. As a result, the blade 24a is sharpened and the dressing board 30 is exposed on the bottom surface of the cutting groove 29 (first dressing process).

  Next, the second dressing process is performed after the first dressing process. The dressing board 30 is cut and cut halfway along the cutting groove 29 with the blade 24b. If necessary, a plurality of lines are cut along a plurality of cutting grooves 29 formed by the blade 24a. As a result, the blade 24b is conspicuous (second dressing step). Since the thickness of the blade 24b is thinner than the thickness of the blade 24a, the blade 24b does not contact the first dressing board 28 during the second dressing process. Further, it is not necessary to replace the dressing boat before the second dressing process, and the second dressing process can be performed immediately after the completion of the first dressing process, which is efficient. After finishing the sharpening of the blade 24a and the blade 24b, the laminated dressing board 26 shown in FIG. 4 is removed from the chuck table 16, and the workpiece 2 shown in FIG. Then, cutting is performed by a well-known step cut method.

  Then, the cutting method which solves the said other technical subject is demonstrated. FIG. 6 shows another embodiment of the laminated dressing board according to the present invention that can be suitably used in a so-called inline dress. The laminated dressing board 38 according to another embodiment is formed in an outer shape corresponding to the shape of the workpiece 2 so as to be disposed adjacent to the workpiece 2. Since the workpiece 2 is a disk-shaped semiconductor wafer, the laminated dressing board 38 of the embodiment is formed in an arc shape along the outer diameter of the semiconductor wafer.

  The laminated dressing board 38 includes a dressing board 40 that is a first dressing board suitable for sharpening the blade 24a and a dressing board 42 that is a second dressing board suitable for sharpening the blade 24b. The dressing board 42 is fixed to the lower surface of the dressing board 40. As shown in FIG. 7, the thickness of the workpiece 2 (the thickness of the workpiece 2) when the workpiece 2 is cut by the blade 24 b along the cutting groove 50 after the cutting groove 50 is formed. The thickness obtained by subtracting the depth of the cutting groove 50 from the thickness) and the thickness of the dressing board 42 are the same. Further, the total thickness of the dressing board 40 and the dressing board 42 is formed to be the same as the cutting thickness of the workpiece 2. In the illustrated embodiment, the total thickness of the laminated dressing board 38 is 400 μm, which is the same as the total thickness of the workpiece 2, the thickness of the dressing board 40 is 150 μm, and the thickness of the dressing board 38 is 250 μm. Yes.

  The laminated dressing board 38 is disposed adjacent to the outer periphery of the workpiece 2. In the illustrated embodiment, the work piece 2 is positioned in the circular opening 46 on the adhesive surface of the mounting tape 48 extending across the circular opening 46 in the center of the support frame 44, and the back surface is attached. Has been. The laminated dressing board 38 is adhered to the adhesive surface of the adhesive tape 48 adjacent to the workpiece 2. The laminated dressing board 38 is stuck at a position that spans all the cutting lines on one side of the plurality of division lines formed in a lattice shape.

  The workpiece 2 and the laminated dressing board 38 attached to the support frame 44 shown in FIG. 6 with the adhesive tape 48 are sucked and held on the chuck table 16 of the cutting apparatus. Next, rotation of the blade 24a and the blade 24b is started, and supply of cutting water is started. First, as shown in FIG. 7A, a cutting groove forming step is performed. In the cutting groove forming step, the dressing board 40 in the laminated dressing board 38 is cut over the entire thickness by the blade 24a to form a cutting groove in the laminated dressing board 38, and the blade 24a is conspicuous and the bottom of the cutting groove is formed. The dressing board 42 is exposed. Subsequently, the blade 24a cuts and cuts 150 μm from the surface 2a of the workpiece 2 to form a cutting groove 50 having a depth of 150 μm in the workpiece 2.

  Next, a dividing step of dividing the workpiece 2 along the cutting groove 50 that has performed the cutting groove forming step is performed. As shown in FIG. 7B, the dressing board 42 is cut along the cutting groove 50 of the laminated dressing board 38 to sharpen the blade 24 b and divide the laminated dressing board 38. Subsequently, the blade 24b is cut to the adhesive tape 48, the workpiece 2 is cut along the cutting groove 50 of the workpiece 2, and the workpiece 2 is divided. The cutting groove forming process and the dividing process are sequentially performed along all the planned dividing lines 4. The thickness of the dressing board 40 is made the same as the depth of the cutting groove 50 formed from the surface 2a of the workpiece 2 by the blade 24a, and the thickness of the dressing board 38 is the workpiece after the cutting groove 50 is formed. 2 is made the same as the cutting thickness of the workpiece 2 when cutting by the blade 24b along the cutting groove 50, and the two types of blades 24a and 24b are sharpened by the optimum dressing boards 40 and 42, respectively. Can do.

  In the illustrated embodiment, the laminated dressing board 38 is disposed upstream in the cutting of the workpiece 2 and the dressing board 38 is cut prior to cutting the workpiece 2 with the blades 24a and 24b. The method is shown (in FIG. 6, the laminated dressing board 38 is arranged on the left side with respect to the work piece 2). May be. In that case, the dressing board 38 is cut following the cutting of the one-line workpiece 2. Further, the laminated dressing board 38 is formed in an annular shape surrounding the periphery of the workpiece 2, and the dressing board 38 is cut prior to cutting the grid-like division planned lines 4 of the workpiece 2. The dressing board 38 can be cut and sharpened after cutting the dividing line 4 while making the sharpening.

2 Workpiece 4 Line to be divided 14 Cutting means 16 Chuck table 24a Blade (first blade)
24b Blade (second blade)
26, 38 Laminated dressing board 28, 40 Dressing board (first dressing board)
30, 42 Dressing board (second dressing board)

Claims (5)

A first dressing board for conspicuous a first blade containing abrasive grains;
A second layer laminated and secured to the lower surface of the first dressing board for conspicuous a second blade containing abrasive grains different from the first blade and having a thickness smaller than the first blade And a dressing board.   The first blade is a blade for cutting from the exposed surface of the workpiece to form a cutting groove in the workpiece, and the second blade is cut along the cutting groove and The laminated dressing board according to claim 1, which is a blade for dividing a workpiece.   The thickness of the second dressing board is the same as the thickness of the work piece cut by the second blade along the cut groove after the cut groove is formed, The laminated dressing board according to claim 2, wherein the total thickness of the first dressing board and the second dressing board laminated is the same as the thickness of the workpiece. Use the laminated dressing board according to any one of claims 1 to 3,
Cutting the first dressing board in the laminated dressing board over its thickness with the first blade to form a cutting groove in the laminated dressing board, sharpening the first blade and the cutting A first dressing step for exposing the second dressing board to the bottom of the groove;
After the first dressing step, the second dressing step of cutting the second dressing board along the cutting groove with the second blade and sharpening the second blade;
A dressing method using a laminated dressing board composed of The laminated dressing board according to claim 3 is disposed adjacent to the outer periphery of the workpiece,
Cutting the first dressing board in the laminated dressing board over its thickness with the first blade to form a cutting groove in the laminated dressing board, sharpening the first blade and the cutting A cutting groove forming step of exposing the second dressing board to the bottom surface of the groove and subsequently or prior to cutting the workpiece with the first blade to form a cutting groove on the workpiece;
After the cutting groove forming step, the second dressing board is cut along the cutting groove of the laminated dressing board, the second blade is sharpened and the laminated dressing board is divided, and subsequently or Dividing the workpiece by cutting the workpiece along the cutting groove of the workpiece with the second blade in advance, and dividing the workpiece;
A cutting method comprising:

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