JP2005096052A - Method for dividing micromachine wafer and dicing frame - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To divide a micromachine wafer into micromachine chips without damaging a micromachine, lowering cutting quality and adhering contaminant to the surface, when cutting the micromachine wafer. <P>SOLUTION: The micromachine wafer 1 is held in a chuck table 44. A layer 6 of machining water is formed on the surface of the micromachine wafer 1. A rotating cutting blade 46a is cut into a street. By relatively cutting and moving the chuck table 44 and a cutting means 46, the micromachine wafer 1 is divided into the micromachine chips. Force of the machining water rotating with high speed rotation of the cutting blade 46 is weakened by the layer 6 of the machining water. Since pressure of jetted machining water is also weakened by the layer 6 of the machining water, the micromachine is not damaged by the machining water. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of cutting a micromachine wafer to divide it into micromachine chips and a dicing frame that can be used to implement this method.

  In a semiconductor wafer, a plurality of circuits are partitioned by streets formed in a lattice shape and formed on the surface side, and the streets are cut into vertical and horizontal directions to be divided into semiconductor chips for each circuit. At the time of cutting, a cutting blade that rotates at high speed cuts into the street, so that cutting waste (contamination) generated by the cutting adheres to the surface of the semiconductor wafer. Therefore, in order to prevent the adhesion of contaminants and remove the adhered contaminants, relatively high-pressure machining water is ejected at the locations where the semiconductor wafer and the cutting blade are in contact (see, for example, Patent Document 1). In addition, a technique is disclosed that floats and removes foreign matter adhering to the surface by cutting a semiconductor wafer in water (see, for example, Patent Document 2).

JP 2001-267272 A JP-A-11-111647

  However, when the object to be cut is not a normal semiconductor wafer but a micromachine wafer, a micromachine is formed on the surface. Therefore, when high-pressure machining water is ejected as in the technique disclosed in Patent Document 1, the micromachine is ejected. There is a problem that the micromachine on the surface is damaged by the pressure of the processing water to be processed or by the momentum of the processing water that rotates with the high speed rotation of the cutting blade. On the other hand, if the pressure of the ejected working water is lowered, contamination adheres to the surface, and if the rotational speed of the cutting blade is lowered, the cutting quality is lowered.

  Further, in Patent Document 2, since the depth of the recess in which the cooling water is accumulated depends on the thickness of the frame, the depth of the recess cannot be adjusted according to the thickness of the wafer or the like.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to divide a micromachine wafer into micromachine chips without damaging the micromachine, without deteriorating the cutting quality, and without causing contamination on the surface.

  In order to solve the above-described problems, the present invention holds a workpiece on a chuck table and relatively moves the chuck table and a cutting means having a cutting blade while supplying the machining water to move the workpiece. In the case of division, the workpiece is a micromachine wafer formed on the surface by dividing a plurality of micromachine chips by the street, forming a layer of processing water on the surface of the micromachine wafer, and cutting a rotating cutting blade into the street. The gist is to divide the micromachine wafer into micromachine chips by moving the chuck table and the cutting means relative to each other.

  The micromachine wafer is integrated with the dicing frame having an opening of a size that can accommodate the micromachine wafer via a tape, and a ring-shaped water stop wall is formed on one surface of the dicing frame, The processed water layer is preferably formed inside the water blocking wall. The water blocking wall is preferably formed of a flexible member such as a sponge. The water blocking wall only needs to be formed on the outer peripheral side of the micromachine wafer. For example, the water blocking wall may be attached to a tape and formed on the tape.

  In addition, the thickness of the processing water layer is preferably 2 mm to 5 mm, the cutting movement speed is 5 mm / second to 15 mm / second, and the processing water supply amount is 0.5 liter / minute to 1.0 liter / second. Minutes are preferred.

  Further, the present invention is used to implement the above method, and is formed in a ring shape having an opening of a size capable of accommodating a micromachine wafer, and a water blocking wall for retaining processing water is formed in a ring shape on the surface. A formed dicing frame is provided. In this dicing frame, the water blocking wall is preferably detachable, and is preferably formed of a flexible member such as a sponge.

  In the present invention, the workpiece is a micromachine wafer having a micromachine formed on the surface, and a layer of processing water is formed on the surface for cutting, so the cutting blade rotates at high speed with the layer of processing water. The momentum of the processing water that is rotated around is reduced, and the micromachine is not damaged by the rotating processing water. Further, since the pressure of the processing water to be ejected is weakened by the layer of the processing water, the micromachine is not damaged by the processing water to be ejected. Furthermore, since the surface of the micromachine wafer is covered with the processing water, the contamination does not adhere to the micromachine, and the quality of the micromachine is not adversely affected.

  In addition, by forming a water stop layer on the dicing frame to form a layer of processed water, the existing dicing frame can be used, and the cutting device is not modified, which can be easily realized. Yes, the thickness of the working water can be freely adjusted by adjusting the height of the water blocking wall. Furthermore, if the water blocking wall is formed of a sponge, the cutting blade will not be damaged even if the cutting blade contacts the water blocking wall.

  As an embodiment of the present invention, a case where the micromachine wafer 1 shown in FIG. 1 is cut and divided into micromachine chips will be described. Streets 11 are formed in a lattice shape on the surface 10 of the micromachine wafer 1, and micromachines are formed in regions partitioned by the streets 11, and the streets 11 are cut vertically and horizontally to form individual micromachine chips 12. Divided.

  As shown in FIG. 1, a micromachine wafer 1 to be cut is attached to a tape 2. The tape 2 is attached to the back surface of the dicing frame 3 having an opening 30 large enough to accommodate the micromachine wafer 1 to close the opening 30, and the back surface of the micromachine wafer 1 is attached to the adhesive surface of the tape 2. As a result, the micromachine wafer 1 is integrated with the dicing frame 3 via the tape 2.

  The micromachine wafer 1 shown in FIG. 1 can be divided into micromachine chips using, for example, a cutting device 4 shown in FIG. In the cutting device 4 shown in FIG. 2, a plurality of micromachine wafers 1 (hereinafter simply referred to as micromachine wafers 1) integrated with the dicing frame 3 via the tape 2 are accommodated in a cassette 40.

  The micromachine wafer 1 accommodated in the cassette 40 is placed in the temporary placement area 42 by the dicing frame 3 being gripped and pulled out by the carry-in / out means 41. Then, the micromachine wafer 1 is adsorbed by the transport means 43 and the transport means 43 is rotated to be transported to the chuck table 44 and sucked and held.

  The chuck table 44 is movable in the X-axis direction, and an alignment unit 45 including an imaging unit 45a is disposed above the movement path of the chuck table 44. A cutting means 46 having a cutting blade 46 a is disposed on the + X direction extension line of the alignment means 45.

  The micromachine wafer 1 held on the chuck table 44 is positioned immediately below the alignment means 45 by the movement of the chuck table 44, the surface is imaged by the imaging means 45a, and the street to be cut is detected by processing such as pattern matching, The street and the cutting blade 46a are aligned in the Y-axis direction. Further, when the chuck table 44 moves in the + X direction, the micromachine wafer is positioned in the vicinity of the cutting means 46.

  As shown in FIG. 3, in the cutting means 46, a cutting blade 46a is mounted on the tip of a spindle 46b having an axis in the Y-axis direction, and the cutting blade 46a is covered with a blade cover 46c. Further, a machining water nozzle 46d is disposed so as to sandwich the cutting blade 46a from both sides (only one of them is shown in FIG. 3), and the lower part of the blade cover 46c is machined in a direction parallel to the axis of the spindle 46b. Water supply means 46e is provided. The cutting means 46 can move in the Y-axis direction as a whole.

  As shown in FIG. 4, a ring-shaped water blocking wall 5 is formed on one surface of the dicing frame 3. The water blocking wall 5 is preferably formed of a flexible member such as a sponge. The water blocking wall 5 may be formed from the beginning, or may be attached before cutting so as to be detachable.

  When the micromachine wafer 1 is cut, as shown in FIG. 5, the machining water is caused to flow out from the machining water nozzle 46d to the micromachine wafer 1 and the machining water is also ejected from the machining water supply means 46e. Processing water is retained on the surface of the wafer 1 and on the tape 2 to form a processing water layer 6. This processed water layer 6 is formed inside a water blocking wall 5 attached to the surface of the dicing frame 3. For example, the thickness is about 2 mm to 5 mm, but the height of the water blocking wall 5 is adjusted. The thickness of the processing water layer 6 can also be adjusted.

  When the chuck table 44 moves in the X-axis direction in the state where the processing water layer 6 is formed, and the cutting blade 46a that rotates at high speed (for example, about 30000 RPM) cuts into the street of the micromachine wafer 1, the chuck table 44 and the cutting means The street is cut by relative cutting movement with respect to 46. The speed of cutting movement is preferably 5 mm / second to 15 mm / second.

  At the time of cutting, the machining water is rotated by the high-speed rotation of the cutting blade 46a. However, since the machining water layer 6 is formed, the momentum of the rotation is weakened. Further, the pressure of the processing water ejected from the processing water nozzle 46 d and the processing water supply means 46 e is also weakened by the processing water layer 6. Therefore, the micromachine is not damaged by the processing water that is rotated and the processing water that is spouted.

  Further, contamination occurs when the street is cut, but since the surface of the micromachine wafer 1 is covered with the processing water because the processing water layer 6 is formed on the micromachine wafer 1, the processing water Contamination floats on the surface side of the layer 6, and no contamination adheres to the surface of the micromachine wafer 1. Therefore, a micromachine chip with good quality can be obtained.

  At the time of cutting, the chuck table 44 moves in the X-axis direction so that the water blocking wall 5 may come into contact with the cutting blade 46a. However, when the water blocking wall 5 is formed of a flexible member such as a sponge, Even if such contact occurs, the cutting blade 46a is not damaged. Further, even if the processing water leaks from the sponge, the processing water is always supplied, so that the thickness of the processing water layer 6 is maintained.

  The above-described cutting is performed by indexing and feeding the cutting means 46 in the Y-axis direction for each street interval, so that the chuck table 44 reciprocates in the X-axis direction and the cutting blades 46a cut into the respective streets. All streets are cut. Further, the chuck table 44 is rotated 90 degrees to perform the same cutting, whereby all streets are cut vertically and horizontally and divided into individual micromachine chips.

  In the present invention, by forming a layer of processing water, it is possible to reduce the momentum of the processing water accompanying the rotation of the cutting blade and the pressure of the processing water to be ejected. It can be used to divide into micromachine chips.

It is a perspective view which shows a micromachine wafer, a tape, and a dicing frame. It is a perspective view which shows an example of a cutting device. It is a perspective view which shows the cutting means which comprises the cutting device. It is a perspective view which shows the state with which the dicing frame to which the water stop wall was attached, and the micromachine wafer were united. It is sectional drawing which shows a mode that it cuts in the state in which the layer of process water was formed.

Explanation of symbols

1: Micromachine wafer 10: Surface 11: Street 12: Micromachine chip 2: Tape 3: Dicing frame 30: Opening part 4: Cutting device 40: Cassette 41: Loading / unloading means 42: Temporary storage area 43: Transfer means 44: Chuck table 45: Alignment means 45a: Imaging means 46: Cutting means 46a: Cutting blade 46b: Spindle 46c: Blade cover 46d: Work water nozzle 46e: Work water supply means 5: Water blocking wall 6: Work water layer

Claims (8)

A chuck table for holding the workpiece, a cutting means having a cutting blade for cutting the workpiece held on the chuck table, and a processing water supply means for supplying the processing water to the workpiece. A method of dividing the workpiece while supplying a machining water by relatively cutting and moving the chuck table and the cutting means using a cutting device provided;
The workpiece is a micromachine wafer in which a plurality of micromachine chips are defined by a street and formed on the surface, the micromachine wafer is held on the chuck table, and a layer of processing water is formed on the surface of the micromachine wafer, A method of dividing a micromachine wafer, wherein the rotating cutting blade is cut into the street and the chuck table and the cutting means are relatively moved by cutting to divide the micromachine wafer into micromachine chips.   The micromachine wafer is integrated with a dicing frame having an opening of a size that can accommodate the micromachine wafer via a tape, and a ring-shaped water stop wall is formed on one surface of the dicing frame. The micromachine wafer dividing method according to claim 1, wherein the processing water layer is formed inside the water blocking wall.   The micromachine wafer dividing method according to claim 2, wherein the water blocking wall is formed of a sponge.   The micromachine wafer dividing method according to claim 1, wherein the processing water layer has a thickness of 2 mm to 5 mm.   5. The micromachine wafer according to claim 1, wherein a cutting movement speed is 5 mm / second to 15 mm / second, and a supply amount of processing water is 0.5 liter / minute to 1.0 liter / minute. How to split.   A dicing frame formed in a ring shape having an opening having a size capable of accommodating a micromachine wafer, and having a water stop wall for retaining processing water formed in a ring shape on the surface.   The dicing frame according to claim 6, wherein the water blocking wall is detachable.   The dicing frame according to claim 6 or 7, wherein the water blocking wall is formed of a sponge.

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