JP6418798B2 - Polishing pad deburring device - Google Patents

Description

  The present invention relates to a polishing pad deburring device for removing burrs generated when a polishing liquid holding groove is formed on the surface of a polishing pad.

  Concentric or lattice-like grooves for holding a polishing liquid are formed on the surface of a polishing pad for polishing a semiconductor substrate or the like. Patent Document 1 discloses a polishing apparatus that removes shavings generated when cutting this type of polishing liquid holding groove with high-pressure pure water.

JP2004-342985

  By the way, when the polishing liquid retaining groove is cut and formed on the surface of the polishing pad, burrs are generated particularly at the opening edge of the groove in addition to the shavings. This becomes serious when the polishing liquid retaining groove is formed by cutting again in the process of regenerating the used polishing pad. Such burrs cannot be completely removed by spraying the high-pressure pure water disclosed in Patent Document 1 above, and burrs are exclusively removed manually. In this operation, a burr of about 50 μm generated in a groove width of about 0.2 mm is searched using a loupe and removed with a knife or tweezers, and there is a problem that much labor is required.

  Therefore, the present invention solves such problems, and an object of the present invention is to provide a polishing pad deburring device capable of quickly removing burrs generated when forming a polishing liquid holding groove without requiring manual operation. And

In order to achieve the above object, according to the first aspect of the present invention, the polishing liquid holding groove (P1) formed by cutting relative to the surface of the polishing pad (P) by cutting relative to the surface of the polishing pad (P) is provided. A groove detecting means (61) for detecting and a blade edge extending over the groove width of the polishing liquid holding groove (P1) are provided, and the polishing liquid holding groove ( End mill (621) that is moved along P1) and cuts the burrs (B) generated at the opening edge of the polishing liquid retaining groove (P1), and the polishing based on the detection signal of the groove detecting means (61). Groove shape acquisition means (7) for acquiring the shape of the polishing liquid holding groove (P1) formed on the pad (P), and the end mill (based on the acquired shape of the polishing liquid holding groove (P1)) 621) is driven to move along the polishing liquid holding groove (P1). A motion means (32, 42, 52), and wherein the end mill (621) of the cutting edge is formed in a triangular cross section facing the vertex the in the polishing liquid holding groove (P1). In this case, the end mill is moved toward the polishing liquid holding groove (P1) to a position where the cutting edge formed in a triangular cross section is substantially equal to the groove width of the polishing liquid holding groove (P1). The contact angle (θ) is preferably 30 to 60 degrees with respect to the surface of the polishing pad (P).

In the first aspect of the invention, the polishing liquid holding groove of the polishing pad is detected and its shape is acquired, and the blade object is moved along the polishing liquid holding groove based on the acquired shape of the polishing liquid holding groove. Thus, burrs generated at the opening edge of the polishing liquid retaining groove can be quickly removed without any manual operation by automatic operation. Moreover, the burr can be efficiently cut off by the rotating end mill.

  In the second invention, a laser displacement meter (61) is used as the groove detecting means.

  According to the second aspect of the invention, not only the polishing liquid holding groove but also the burrs generated in the polishing liquid holding groove can be detected by the laser displacement meter. Therefore, only the polishing liquid holding groove in which the burrs are generated is selected to efficiently remove the burrs. be able to.

In the third invention, the surface roughness Ra of the edge of the end mill (621) is 1 μm or less.

  The reference numerals in the parentheses indicate the correspondence with specific means described in the embodiments described later.

  As described above, according to the deburring device for a polishing pad of the present invention, burrs generated when forming the polishing liquid retaining groove can be quickly removed without requiring manual operation.

1 is an overall perspective view of a deburring device showing an embodiment of the present invention. It is a block diagram which shows the control system of a deburring apparatus. It is an expansion perspective view of the turntable part of a deburring apparatus. It is an expansion perspective view of the end mill mounting part of a deburring apparatus. It is sectional drawing of the end mill blade edge which moves along a polishing liquid holding groove. It is a wave form diagram which shows an example of the output signal of a laser displacement meter.

  The embodiment described below is merely an example, and various design improvements made by those skilled in the art without departing from the gist of the present invention are also included in the scope of the present invention.

  FIG. 1 is an overall perspective view of the deburring device. FIG. 2 shows a control system of the deburring device. 1 will be described below with reference to the control system of FIG. The deburring device includes a box-shaped base 1, and a disk-shaped rotary table 2 is supported on the base 1 so as to be rotatable in a horizontal posture. The turntable 2 is rotated to a desired rotation position by a drive motor 21 installed in the base 1. The rotational position of the turntable 2 is detected by a rotary encoder 22. If a stepping motor is used as the drive motor 21, the rotary encoder 22 is not necessary.

  An X-axis guide rail 3 extends horizontally so as to cross the plate surface above the turntable 2, and the base end of the guide rail 3 is provided on the base 1 so as to be orthogonal thereto. The shaft guide rail 4 is supported so as to be movable along the shaft guide rail 4. That is, the base end 3 of the X-axis guide rail is fixed to a slider 41 that is movably provided along the Y-axis guide rail 4. The slider 41 is connected to the Y-axis drive motor 42 via a drive mechanism (not shown), and the X-axis guide rail 3 is maintained along the Y-axis guide rail 4 by the Y-axis drive motor 42 while maintaining its horizontal posture. Moved. The amount of movement at this time is detected by the Y-axis rotary encoder 43.

  A slider 31 (FIG. 3) is provided so as to be movable along the X-axis guide rail 3. The slider 31 is connected to an X-axis drive motor 32 via a drive mechanism (not shown). Moved. The amount of movement at this time is detected by the X-axis rotary encoder 33. The slider 31 is provided with a Z-axis guide rail 5 extending in a vertical direction perpendicular to the plate surface of the turntable 2. A slider 51 is provided on the Z-axis guide rail 5 so as to be movable along the Z-axis guide rail 5. The slider 51 is connected to a Z-axis drive motor 52 through a drive mechanism (not shown). Moved. The amount of movement at this time is detected by the Z-axis rotary encoder 53.

  A scanning laser displacement meter 61 is mounted on one side of the standing wall of the slider 51 downward (FIG. 4). Further, a spindle 62 with a built-in motor is provided on the other surface of the standing wall downward, and an end mill 621 is attached to the tip of the spindle 62. With such a structure, the slider 51 and the laser displacement meter 61 and the spindle 62 provided integrally therewith can be moved to an arbitrary position within a fixed three-dimensional space above the turntable 2. The drive motors 21, 32, 42, 52, the rotary encoders 22, 33, 43, 53, the laser displacement meter 61, and the spindle 62 are connected to a control device 7 with a built-in CPU provided in the base 1 ( 2), the following operation is realized by the control device 7.

  In the deburring apparatus having the above-described structure, a polishing pad P having substantially the same diameter and having a polishing liquid holding groove formed concentrically on the upper surface is bonded onto the turntable 2 (FIG. 2). The formation of the polishing liquid retaining groove can be easily performed by replacing the spindle 62 provided on the slider 51 with a cutting bit and using the deburring device as the groove forming device.

  The rotating position of the polishing pad P and the movement of the laser displacement meter 61 are moved while rotating the rotating table 2 and moving the laser displacement meter 61 in the radial direction of the polishing pad P with respect to the polishing pad P bonded on the rotating table 2. From the position information, the position of the polishing liquid holding groove on the polishing pad P is detected at regular intervals. Interpolation is appropriately performed on the discrete position information of the polishing liquid holding grooves detected at regular intervals to obtain an overall continuous shape of the polishing liquid holding grooves.

Then, according to the obtained shape information of the polishing liquid holding groove, the spindle 62 is moved while being rotated to perform deburring. That is, as shown in FIG. 5, the spindle 62 is moved in the Z-axis direction in advance to a position where the cutting edge of the end mill 621 provided at the lower end of the spindle 62 becomes substantially equal to the groove width of the polishing liquid holding groove P1. While rotating the spindle 62 in this state, the slider 51 is moved in the two-dimensional plane of the XY axis along the polishing liquid holding groove P1. As a result, the burrs B (dashed lines in FIG. 5) generated at the groove opening edge of the polishing liquid holding groove P <b> 1 are cut off by the cutting edge of the end mill 621. At this time, the turntable 2 is stopped. Note that the end mill 621 may be one having a contact angle θ (FIG. 5) of the blade edge with respect to the polishing pad surface of 30 degrees to 60 degrees and a surface roughness of the blade edge of Ra1 μm or less.

  The cross-sectional shape of the polishing liquid holding groove P1 and the burr B generated in the groove P1 can be known from the output signal from the laser displacement meter 61 as shown in FIG. The spindle 62 may be selectively moved only in the groove P1. Further, the shape of the polishing liquid holding groove P1 on the polishing pad P is not necessarily limited to the concentric shape, and may be, for example, a lattice shape. Further, instead of the end mill, a cutting tool or knife having substantially the same width as the groove width of the polishing liquid holding groove P1 may be used. Further, it is not always necessary to stop the turntable during deburring, and it may be rotated in synchronization with the spindle.

DESCRIPTION OF SYMBOLS 1 ... Base, 2 ... Rotary table, 3 ... X-axis guide rail, 32 ... X-axis drive motor (drive means), 4 ... Y-axis guide rail, 42 ... Y-axis drive motor (drive means), 5 ... Z-axis Guide rail, 52 ... Z-axis drive motor (drive means), 61 ... Laser displacement meter (groove detection means), 62 ... Spindle, 621 ... End mill (blade object), 7 ... Control device (groove shape acquisition means), B ... Burr, P: Polishing pad, P1: Polishing liquid holding groove.

Claims (4)

A groove detecting means for detecting a polishing liquid holding groove that is moved relative to the surface of the polishing pad and cut and formed on the surface of the polishing pad; and a cutting edge that extends over the groove width of the polishing liquid holding groove, An end mill that moves around the polishing liquid holding groove while rotating around an axis in a direction of entering the liquid holding groove and cuts off burrs generated at the opening edge of the polishing liquid holding groove; and the groove detection Groove shape acquisition means for acquiring the shape of the polishing liquid holding groove formed on the polishing pad based on the detection signal of the means; and the end mill based on the acquired shape of the polishing liquid holding groove. A deburring device for a polishing pad, comprising: a driving unit that moves and drives along a holding groove; and the end mill has a cutting edge formed in a triangular cross section whose apex faces the polishing liquid holding groove. The end mill has a triangular cross section and the cutting edge is moved toward the polishing liquid holding groove to a position substantially equal to the groove width of the polishing liquid holding groove. Is a deburring device for a polishing pad having an angle of 30 to 60 degrees. 2. The polishing pad deburring device according to claim 1, wherein a laser displacement meter is used as the groove detecting means. The deburring device for a polishing pad according to any one of claims 1 to 3, wherein a surface roughness Ra of a cutting edge of the end mill is 1 µm or less.

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