JP2015020240A - Cutting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutting device in which a replacing frequency of a chuck table can be reduced more than before.SOLUTION: The cutting device has: light emitting means 60; light receiving means 62 that faces the light emitting means and receives light emitted from the light emitting means; and a height detection portion including a height detection surface 64 positioned at the same height as that of a light passage outside the light passage between the light emitting means and the light receiving means, and also comprises: blade detecting means 36 that detects a height position of the lowermost end of a cutting blade by positioning the cutting blade between the light emitting means and the light receiving means; height position detecting means that detects a height position of a holding surface of holding means and a height position of the height detection surface of the blade detecting means; and calculating means that calculates a position obtained by adding a difference between the height position of the holding surface and the height position of the height detection surface detected by the height position detecting means to the lowermost end position of the cutting blade detected by the blade detecting means, as a reference position for the cutting blade relative to the holding surface 18a.

Description

  The present invention generally relates to a cutting apparatus, and more particularly, to a setup mechanism that detects an origin position (reference position) of a cutting blade.

  A semiconductor wafer or the like is cut by a cutting device generally called a dicing device. The cutting apparatus cuts a workpiece such as a semiconductor wafer with a rotating cutting blade. This cutting blade is worn away by use and its diameter decreases.

  For this reason, it is necessary for the cutting device to adjust the reference position in the cutting direction of the cutting blade in response to a decrease in the diameter of the cutting blade, and a blade detection mechanism (non-contact setup sensor) that detects this reference position in a non-contact manner. Generally equipped. (For example, see JP-A-8-174416).

  However, even in a cutting machine equipped with a non-contact setup sensor, in order to detect the positional relationship between the chuck table holding surface and the non-contact setup sensor, the frame body is flush with the chuck table holding surface during use. A contact setup was performed in which the cutting blade was brought into contact with the upper surface of the steel plate and the origin position of the cutting blade was detected (see, for example, JP-A-61-71967).

JP-A-8-174416 JP-A-61-71967

  When the cutting blade comes into contact with the chuck table frame, the cutting blade slightly cuts into the chuck table frame. Since a cut mark is formed in the part once cut, setup cannot be performed again in the same part.

  Therefore, contact setup is carried out while changing the position each time, but the chuck table that does not have the space for carrying out the setup is replaced, and there is a problem that the cost is very high.

  This invention is made | formed in view of such a point, The place made into the objective is providing the cutting device which can reduce the replacement frequency of a chuck table conventionally.

  According to the present invention, there is provided a cutting device comprising: a holding unit having a holding surface for holding a workpiece; and a cutting unit having a cutting blade for cutting the workpiece held by the holding unit. A light receiving means that faces the light emitting means and receives the light emitted from the light emitting means, and a height detection at the same height position as the optical path outside the optical path between the light emitting means and the light receiving means A height detecting unit including a surface, and a blade detecting means for detecting a height position of a lowermost end of the cutting blade by positioning the cutting blade between the light emitting means and the light receiving means, Height position detecting means for detecting the height position of the holding surface of the holding means and detecting the height position of the height detecting surface of the blade detecting means, and the cutting blade detected by the blade detecting means At the lowest position of the Calculating means for calculating a position obtained by adding a difference between the height position of the held holding surface and the height position of the height detection surface as a reference position of the cutting blade with respect to the holding surface; A cutting device is provided.

  Preferably, the height position detecting means includes an image pickup means for picking up an image of the surface of the workpiece held by the holding means, a moving means for moving the image pickup means in the vertical direction, and a height position of the image pickup means. Imaging means height position detecting means for detecting.

  The cutting apparatus according to the present invention includes a blade detection unit that detects a lowermost position of a cutting blade, a height position detection that detects a height position of a holding surface of the holding unit and a height detection surface of the blade detection unit. Since the means and the calculating means for calculating the reference position of the cutting blade with respect to the holding surface are provided, the cutting blade can be positioned at a predetermined height position with high accuracy without performing contact setup. Since it is not necessary to perform the contact setup to cut the cutting blade into the holding means, the replacement frequency of the holding means can be reduced as compared with the prior art.

It is a perspective view of the cutting device concerning an embodiment. It is a partial cross section side view of the cutting device shown in FIG. It is a perspective view of a blade detection means (non-contact setup sensor). It is a schematic diagram which shows a mode that the holding surface height of a chuck table and the height detection surface height of a blade detection means are detected using the autofocus of the microscope incorporated in the imaging unit. It is a side view which shows a mode that the position of the lowest end of a cutting blade is detected by a blade detection means.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Referring to FIG. 1, a perspective view of a cutting device 2 according to an embodiment of the present invention is shown. On the front side of the cutting device 2, an operation panel 4 is provided for an operator to input instructions to the device such as machining conditions. In the upper part of the apparatus, there is provided a display monitor 6 such as a CRT on which a guidance screen for an operator and an image captured by an imaging unit described later are displayed.

  A plurality of wafers 11 to be cut by the cutting apparatus 2 are attached to a dicing tape T attached to an annular frame F, and then stored in a wafer cassette 8. The wafer cassette 8 is placed on a cassette elevator 9 that can move up and down.

  Behind the wafer cassette 8 is disposed a carry-out unit 10 for carrying the wafer 11 before cutting from the wafer cassette 8 and carrying the wafer after cutting into the wafer cassette 8.

  Between the wafer cassette 8 and the carry-in / out unit 10, a temporary placement area 12, which is an area on which the wafer 11 to be carried in / out, is temporarily placed, is provided. An alignment mechanism 14 for centering is provided.

  A transport unit 16 having a swivel arm that sucks and transports the wafer 11 is disposed in the vicinity of the temporary placement area 12. The wafer 11 that is unloaded and centered in the temporary placement area 12 is placed by the transport unit 16. The chuck table 18 is sucked and conveyed onto the chuck table 18, and is sucked and held by the chuck table 18.

  The chuck table 18 is configured to be rotatable and reciprocally movable in the X-axis direction by a machining feed mechanism (not shown). An area to be cut of the wafer 11 is formed above the movement path of the chuck table 18 in the X-axis direction. An alignment unit 22 for detection is provided. Reference numeral 20 denotes a clamp for clamping the annular frame F. A blade detection means (non-contact setup sensor) 36 is disposed adjacent to the chuck table 18.

  The alignment unit 22 includes an imaging unit (imaging means) 24 that images the surface of the wafer 11, and can detect a region to be cut by image processing such as pattern matching based on an image acquired by imaging. The image acquired by the imaging unit 24 is displayed on the display monitor 6. The imaging unit 24 has a microscope equipped with an autofocus mechanism and a CCD camera.

  On the left side of the alignment unit 22, a cutting unit 26 for cutting the wafer 11 held on the chuck table 18 is disposed. The cutting unit 26 is configured integrally with the alignment unit 22, and both move together in the Y-axis direction and the Z-axis direction.

  The cutting unit 26 is configured by mounting a cutting blade 30 having a cutting edge on the outer periphery of the end of a rotatable spindle 28 and is movable in the Y-axis direction and the Z-axis direction. The movement of the cutting unit 26 in the Y-axis direction is achieved by an index feed mechanism (not shown).

  Reference numeral 34 denotes a spinner cleaning unit that cleans the wafer 11 that has been subjected to the cutting process. The wafer 11 that has been subjected to the cutting process is transported to the spinner cleaning unit 34 by the transport unit 32 and is spin cleaned and spin dried by the spinner cleaning unit 34. .

  Referring to FIG. 2, a partial cross-sectional side view of the cutting device 2 is shown. The chuck table 18 is moved in the X-axis direction in FIG. 1 by a machining feed mechanism (X-axis feed mechanism) 38 composed of a ball screw and a pulse motor.

  The cutting unit 26 includes a spindle 28 that is rotatably accommodated in a spindle housing 27, a motor 25 that rotates the spindle 28, and a cutting blade 30 that is attached to the tip of the spindle 28. In FIG. 2, the mounting position of the imaging unit 24 is schematically shown, and the imaging unit 24 is mounted so as to be movable in the Y-axis direction and the Z-axis direction together with the cutting unit 26.

That is, the cutting unit 26 is moved in the Y-axis direction by an index feed mechanism (Y-axis moving mechanism) 44 composed of the ball screw 40 and the pulse motor 42. The position of the imaging unit 26 in the Y-axis direction is detected by reading the scale of the linear scale 46 with the reading head 48, and the detected value is stored in the memory of the controller of the cutting apparatus 2.

  The cutting unit 26 is moved in the Z-axis direction by a cutting feed mechanism (Z-axis moving mechanism) 54 including a ball screw 50 and a pulse motor 52. The position in the Z-axis direction is detected by reading the scale of the linear scale 56 with the reading head 58, and the detected value is stored in the memory of the controller.

  Referring to FIG. 3, a perspective view of the blade detection means (non-contact setup sensor) 36 is shown. The blade detection means 36 includes an attachment member 37 having a horizontal portion 37 a and a vertical portion 37 b, and the attachment member 37 is disposed adjacent to the chuck table 18.

  The tip of the vertical portion 37b of the attachment member 37 is formed in a U shape that defines a blade intrusion portion 39, and light emitted from the light emitting portion 60 and the light emitting portion 60 of the light emitting means is sandwiched between the blade intrusion portion 39. A light receiving portion 62 of light receiving means for receiving light is disposed.

  Reference numeral 63 denotes an optical path of light emitted from the light emitting unit 60. For example, the light emitting unit 60 is connected to a light source via an optical fiber, and the light receiving unit 62 is connected to a photoelectric conversion unit such as a photodetector via an optical fiber.

  The blade detection unit 36 of this embodiment has a height detection unit including a height detection surface 64 having the same height as the optical path 63 outside the optical path 63. In the horizontal portion 37 a of the mounting member 37, air is supplied to cleaning water supply nozzles 66 a and 66 b for supplying cleaning water whose temperature is adjusted to the end surfaces of the light emitting unit 60 and the light receiving unit 62 and to the end surfaces of the light emitting unit 60 and the light receiving unit 62. Air supply nozzles 68a and 68b to be supplied are disposed.

  In the present embodiment, as schematically shown in FIG. 4, imaging is performed to detect the height of the holding surface 18 a of the chuck table 18 and the height position of the height detection surface 64 of the blade detection unit 36. The autofocus mechanism of the microscope of the unit 24 is used.

The height position detecting means for detecting the height position of the holding surface 18a of the chuck table 18 and detecting the height position of the height detecting surface 64 of the blade detecting means 36 moves the imaging unit 24 and the imaging unit 24 in the vertical direction. A Z-axis moving mechanism 54 for moving the image pickup unit 24, and an image pickup unit position detecting unit including a linear scale 56 for detecting the height position of the image pickup unit 24 and a reading head 58.
In order to detect the height position of the holding surface 18 a of the chuck table 18, the pulse motor 52 of the Z-axis moving mechanism 54 is driven so that the imaging unit 24 gradually approaches the holding surface 18 a of the chuck table 18. By using the autofocus mechanism of the microscope built in, the driving of the pulse motor 52 is stopped when the focus of the microscope matches the holding surface 18a, and the Z-direction position (height position) at that time is set to the linear scale 56. And store the read height position in the memory of the controller.

  Next, the X-axis moving mechanism 38 and the Y-axis moving mechanism 44 are driven to position the imaging unit 24 above the height detection surface 64 of the blade detection unit 36. Then, the pulse motor 52 of the Z-axis moving mechanism 54 is driven, and the imaging unit 24 is gradually brought closer to the height detection surface 64 of the blade detection means 36, and the drive of the pulse motor 52 is stopped when the microscope is in focus. Then, the Z-direction position at this time is read by the linear scale 56, and the read height position is stored in the memory of the controller.

  Since the memory of the controller stores the height position of the holding surface 18a of the chuck table 18 and the height position of the height detection surface 64 of the blade detection means 36, the controller stores the holding surface 18a and the height detection surface 64. The height difference can be easily calculated, and the calculated height position difference is stored in the memory. Once the height difference is detected, it is constant unless the chuck table 18 is replaced with a new chuck table.

  Next, a blade bottom end position detecting step of detecting the bottom end position of the cutting blade 28 (position of the cutting edge in the cutting direction) by the blade detecting means 36 is performed. In this blade lowest end position detection step, as shown in FIG. 5, the pulse motor 52 of the Z-axis feed mechanism 54 is driven to allow the cutting blade 28 to enter the blade entry portion 39 of the blade detection means 36 from above. .

  At this time, when the cutting blade 28 does not block between the light emitting unit 60 and the light receiving unit 62, the amount of light received by the light receiving unit 62 is maximum. As the cutting blade 28 enters the blade intrusion portion 39, the amount by which the cutting blade 28 blocks the light beam emitted from the light emitting portion 60 gradually increases, so the amount of light received by the light receiving portion 62 gradually increases. Decrease.

  When the cutting blade 28 reaches the position connecting the center of the light emitting unit 60 and the light receiving unit 62, the output voltage from the photoelectric conversion unit such as a photodetector connected to the light receiving unit 62 is set to be a reference voltage. ing.

  Accordingly, when the output voltage of the photoelectric conversion unit becomes the reference voltage, the driving of the pulse motor 52 of the Z-axis moving mechanism 54 is stopped, and the Z-direction position at this time is read by the linear scale 56 and stored in the memory of the controller. .

  Then, the difference between the height position of the holding surface 18a detected by the height position detecting means and the height position of the height detecting surface 64 is added to the lowermost position of the cutting blade 28 detected by the blade detecting means 36. This position is set as a reference position of the cutting blade 28 with respect to the holding surface 18 a of the chuck table 18.

  The calculation of the reference position is performed by the calculation means of the controller, that is, the calculation unit. The reference position of the cutting blade 28 is a position where the cutting blade 28 contacts the holding surface 18 a of the chuck table 18, and the position of the cutting blade 30 in the cutting direction is controlled based on this reference position.

  In the above-described embodiment, the height position of the holding surface 18a of the chuck table 18 and the height detection surface 64 of the blade detection means (non-contact setup sensor) 36 are utilized using the autofocus mechanism of the microscope of the imaging unit 24. Since the position is detected, the cutting blade 30 can be positioned at a predetermined height position with high accuracy without performing contact setup. Since it is not necessary to cut the cutting blade 30 into the chuck table 18 by performing contact setup, the replacement frequency of the chuck table 18 can be reduced as compared with the conventional case.

2 Cutting device 18 Chuck table 18a Holding surface 26 Cutting unit 30 Cutting blade 38 Processing feed mechanism (X-axis moving mechanism)
44 Index feed mechanism (Y-axis feed mechanism)
46, 56 Linear scale 48, 58 Reading head 54 Cutting feed mechanism (Z-axis moving mechanism)
36 Blade detection means (non-contact setup sensor)
60 Light Emitting Unit 62 Light Receiving Unit 64 Height Detection Surface

Claims (2)

A cutting device comprising: holding means having a holding surface for holding a workpiece; and cutting means having a cutting blade for cutting the workpiece held by the holding means,
A light-emitting means, a light-receiving means that faces the light-emitting means and receives light emitted from the light-emitting means, and a height at the same height as the optical path outside the optical path between the light-emitting means and the light-receiving means A height detection unit including a detection surface; and a blade detection unit that detects a height position of a lowermost end of the cutting blade by positioning the cutting blade between the light emitting unit and the light receiving unit. ,
A height position detecting means for detecting a height position of the holding surface of the holding means and detecting a height position of the height detecting surface of the blade detecting means;
The difference between the height position of the holding surface detected by the height position detecting means and the height position of the height detecting surface is added to the lowest end position of the cutting blade detected by the blade detecting means. Calculating means for calculating a position as a reference position of the cutting blade with respect to the holding surface;
A cutting apparatus comprising:   The height position detection means detects an image pickup means for picking up an image of the surface of the workpiece held by the holding means, a moving means for moving the image pickup means in the vertical direction, and a height position of the image pickup means. The cutting apparatus according to claim 1, further comprising: an imaging unit height position detection unit.

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