CN102814871B - Processing unit (plant) - Google Patents

Abstract

The present invention provides a processing device capable of adjusting the light intensity of an imaging member to an appropriate light intensity. This processing device has: a chuck table that holds a workpiece; a processing member that performs processing on the workpiece held by the chuck table; and an imaging member that performs processing on the workpiece held by the chuck table. The object is photographed; and the processing feeding member is used to process and feed the chuck table and the processing member, which is characterized in that the imaging member includes: a light source, which illuminates the processed object; a camera, which monitors the processed object The illuminated workpiece is imaged; and a light quantity adjuster for adjusting the light quantity of light irradiated from the light source, the light quantity adjuster has: a rotating plate having a rotating shaft; an opening formed on the rotating plate; a plate through which light irradiated from the light source passes; and a light-shielding plate that changes the amount of light transmitted through the opening between a maximum value and a minimum value corresponding to the rotation angle of the rotation shaft.

Description

Processing device

technical field

The present invention relates to processing devices such as cutting devices and laser processing devices for processing workpieces such as semiconductor wafers.

Background technique

Multiple devices such as IC (Integrated Circuit: Integrated Circuit) and LSI (Large Scale Integrated Circuit: Large Scale Integrated Circuit) are formed on the surface of the wafer divided by the planned division line, and the cutting device (cutting device) or laser processing device The wafer is divided into individual devices along planned division lines, and the divided devices are widely used in electronic equipment such as mobile phones and personal computers.

A processing device such as a cutting device or a laser processing device includes at least: a chuck table that holds a workpiece such as a semiconductor wafer; a processing member that processes the workpiece held by the chuck table; The workpiece held by the chuck table is imaged; and the processing feed member performs processing feeding of the chuck table and the processing member relative to each other.

In general, the imaging means includes a camera for imaging the workpiece and a microscope for enlarging the image captured by the camera, and the imaging means can detect the planned dividing line as the area to be processed and accurately move the cutting tool or The laser processing head is positioned on the predetermined dividing line to be processed.

In the existing processing equipment, in order to perform calibration by detecting the planned dividing line to be processed with the imaging device, the chuck table must be stopped and the area to be cut should be photographed with the imaging device. bad question.

Therefore, the applicant of the present application has proposed following imaging member in Japanese Patent Application Laid-Open No. 2010-76053: it adopts stroboscopic light as light source, and the CCD (Charge Coupled Device: Charge Coupled Device) camera of imaging member and stroboscopic light The imaging area of the wafer is imaged synchronously with the irradiation. According to the cutting apparatus having this imaging means, it is possible to obtain a still image even when the wafer is moving.

Patent Document 1: Japanese Unexamined Patent Publication No. 2010-76053

However, in the cutting device having the imaging means disclosed in Patent Document 1, means for adjusting the light intensity of the strobe light emitted from the strobe light source is not provided. If imaging is performed without adjusting the light intensity of the strobe light, there is a problem that an appropriate captured image may not be obtained. Especially in the case of using a xenon flash lamp as a stroboscopic light source, there is a problem that it is almost impossible to perform stroboscopic photography.

Contents of the invention

The present invention has been made in view of the above point, and an object of the present invention is to provide a processing device having an imaging means having a mechanism capable of adjusting the light intensity of a stroboscopic light source.

According to the present invention, there is provided a processing device including: a chuck table for holding an object to be processed; a processing member for holding an object held by the chuck processing on the workpiece on the table; imaging means for imaging the workpiece held on the chuck table; The chuck table and the processing component are processed and fed relatively, and the processing device is characterized in that the imaging component includes: a light source for illuminating the workpiece; a camera for imaging the illuminated workpiece; and a light quantity adjuster for adjusting the light quantity of light irradiated from the light source, the light quantity adjuster including: a rotating plate having a rotating shaft; an opening formed in the rotating plate for transmitting light irradiated from the light source; and a light shielding plate that transmits light corresponding to the rotation angle of the rotating shaft The amount of light passing through the opening varies between a maximum value and a minimum value.

The imaging means included in the processing device of the present invention is provided with a light quantity adjuster including a shading plate that changes the transmitted light quantity from the light source, so that the light quantity from the light source can be adjusted to be suitable for imaging the workpiece. The amount of light is used to take an image of the area to be processed of the workpiece. In particular, it is very convenient when performing stroboscopic imaging using a light source such as a xenon strobe lamp whose light intensity cannot be adjusted.

Description of drawings

FIG. 1 is a schematic configuration diagram of a cutting device according to an embodiment of the present invention.

Fig. 2 is a perspective view of a semiconductor wafer supported by a ring frame with a diced tape.

3 is a schematic diagram illustrating the configuration and operation of the imaging unit according to the embodiment of the present invention at the time of detection of a planned dividing line.

Fig. 4 is a perspective view of a light quantity adjuster.

FIG. 5 is a schematic diagram illustrating the operation of the imaging unit according to the embodiment of the present invention at the time of checking the state of the cutting groove.

Label description

2: cutting device;

14: X-axis feed mechanism;

20: chuck table;

36: Y-axis feed mechanism;

44: Z-axis feed mechanism;

46: cutting unit;

50: cutting tool;

52: calibration unit;

54: camera unit;

60: water filling chamber;

68: objective lens;

70: Xenon flash lamp;

74: CCD camera;

76: Monitor;

82: light quantity adjuster;

84: pulse motor;

92: Visor.

Detailed ways

Next, the cutting device 2 according to the embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a cutting device 2 . The cutting device 2 includes a pair of guide rails 6 mounted on the stationary base 4 and elongated in the X-axis direction.

The X-axis moving block 8 is moved in the machining feed direction, that is, the X-axis direction, by an X-axis feed mechanism (X-axis feed member) 14 composed of a ball screw 10 and a pulse motor 12 . A chuck table 20 is mounted on the X-axis moving block 8 via a cylindrical support member 22 .

The chuck table 20 has a suction portion (suction chuck) 24 formed of porous ceramics or the like. A plurality of (four in this embodiment) clampers 26 for clamping the ring-shaped frame F shown in FIG. 2 are arranged on the chuck table 20 .

As shown in FIG. 2, on the surface of the semiconductor wafer W as the processing object of the cutting device 2, the first street S1 and the second street S2 are formed orthogonally. A large number of devices D are formed in the divided regions.

The wafer W is attached to a dicing tape T serving as an adhesive tape, and the outer peripheral portion of the dicing tape T is attached to an annular frame F. As shown in FIG. Thus, the wafer W is supported on the ring frame F via the dicing tape T, and the wafer W is supported and fixed on the chuck table by clamping the ring frame F with the clamper 26 shown in FIG. 1 . 20 on.

The X-axis feed mechanism 14 has: a scale 16, which is arranged on the stationary base 4 along the guide rail 6; X coordinate value. The read head 18 is connected to the controller of the cutting device 2 .

A pair of guide rails 28 extending along the Y-axis direction are also fixed on the stationary base 4 . The Y-axis moving block 30 is moved in the Y-axis direction by a Y-axis feed mechanism (index feed mechanism) 36 composed of a ball screw 32 and a pulse motor 34 .

A pair (only one is shown) of guide rails 38 extending in the Z-axis direction is formed on the Y-axis moving block 30 . The Z-axis moving block 40 is moved in the Z-axis direction by a Z-axis feed mechanism 44 composed of a ball screw (not shown) and a pulse motor 42 .

Reference numeral 46 is a cutting unit (cutting member), and a headstock 48 of the cutting unit 46 is inserted into and supported in the Z-axis moving block 40 . A main shaft is accommodated in the main shaft housing 48, and the main shaft is rotatably supported by an air bearing. The main shaft is driven to rotate by a motor (not shown) housed in the headstock 48 , and a cutting tool 50 is detachably attached to the tip of the main shaft.

A calibration unit (calibration member) 52 is mounted on the headstock 48 . The alignment unit 52 has an imaging unit (imaging means) 54 for imaging the wafer W held by the chuck table 20 . The cutting tool 50 and the imaging unit 54 are arranged side by side along the X-axis direction.

Next, the configuration of the imaging unit 54 according to the embodiment of the present invention will be described in detail with reference to FIG. 3 . The imaging unit 54 has a housing 56 housing an objective lens 68 facing the imaging area, and a partition wall 58 having a light-transmitting window 59 is attached near an end portion of the housing 56 .

A water-filled chamber 60 is enclosed in a space partitioned by the end portion of the frame body 56 , the partition wall 58 , and the wafer W held by the chuck table 20 . The distance between the end 56a of the frame 56 and the wafer W held by the chuck table 20 is preferably about 0.5 to 1 mm. During the notch inspection of the wafer W, water is supplied and filled into the water filling chamber 60 from the water source 64 through the on-off valve 66 and the water supply port 62 .

The imaging unit 54 of the present embodiment includes a xenon strobe lamp 70 as a type of strobe light source. Part of the strobe light emitted from the xenon flash lamp 70 is reflected by the beam splitter 72 and irradiates the wafer W held by the chuck table 20 through the objective lens 68 and the light transmission window 59 .

The CCD camera 74 is arranged on the optical axis of the objective lens 68, and the CCD camera 74 images the wafer W irradiated with the stroboscopic light. Images captured by the CCD camera 74 are displayed on a monitor 76 .

A light quantity adjuster 82 for adjusting the light quantity of the light emitted from the xenon flashlamp 70 is arranged between the xenon flashlamp 70 and the beam splitter 72 . As shown in FIG. 4 , the light quantity adjuster 82 includes: a pulse motor 84; a rotating shaft 86, which is connected to the pulse motor 84; a rotating plate 88, which is fixed at the end of the rotating shaft 86; an opening 90, which is formed in the rotation Plate 88 is used to transmit the light irradiated from xenon flash lamp 70; Varies between minimum values.

The light shielding plate 92 is configured to have segments 92a to 92j, and the amount of light transmitted through each segment 92a to 92j is gradually reduced between a maximum value and a minimum value. As another embodiment of the light-shielding plate 92, the light quantity transmitted through the light-shielding plate 92 may be continuously changed between a maximum value and a minimum value.

Referring again to FIG. 3 , the CCD camera 74 takes an image of the imaging area of the wafer W held by the chuck table 20 in synchronization with the emission of the xenon strobe lamp 70 , and the imaged image is displayed on the monitor 76 . The xenon flash lamp 70 , the CCD camera 74 and the pulse motor 84 are connected to and controlled by the control member 80 .

The action of the imaging unit 54 configured as above will be described below. First, the wafer W to be cut is sucked and held by the chuck table 20 , and then the X-axis feed mechanism 14 is driven to position the wafer W directly under the imaging unit 54 .

In the imaging unit 54 of this embodiment, the CCD camera 74 images the imaging area of the wafer W in synchronization with the irradiation of the stroboscopic light from the xenon strobe lamp 70. Therefore, even when the wafer W is still moving, it is possible to obtain a clear still image. image.

When imaging the imaging area of the wafer W by the imaging unit 54, first, the pulse motor 84 of the light quantity adjuster 82 is driven to rotate the light-shielding plate 92 mounted on the rotating plate 88, and the sections 92a to 92j of the light-shielding plate 92 are selected, The light quantity of the stroboscopic light from the xenon strobe lamp 70 is optimized, and the driving of the pulse motor 84 is stopped at a position where the selected section blocks the light path of the stroboscopic light emitted from the xenon strobe lamp 70 .

The selection of the sections 92a to 92j of the light shielding plate 92 is determined as follows: while the light shielding plate 92 is rotated by the pulse motor 84, the CCD camera 74 is used to take an image of the wafer W, and the captured image is observed on the monitor 76 to determine the light shielding plate. Selection of sections 92a-92j of 92.

After the optimal sections 92a to 92j of the light shielding plate 92 are selected, a calibration process is performed. In the alignment process of this embodiment, while moving the wafer W held by the chuck table 20 in the X-axis direction by the X-axis feed mechanism 14, a certain point on the wafer W (let this be point A) The xenon strobe lamp 70 is turned on to illuminate the imaging area of the wafer W when it reaches directly below the imaging unit 54 .

Synchronously with the light emission of the xenon flash lamp 70, the device D at the point A is photographed by the CCD camera 74, and the target pattern consistent with the image of the target pattern stored in the calibration unit 52 is detected, and then the target pattern at the point A is The coordinate values of are stored in the memory of the calibration unit 52 .

Next, move the chuck table 20, and at point B away from point A, take an image of the device D adjacent to the same interval track S1 as the interval track S1 photographed at point A, and detect the target through the same operation pattern, and then store the coordinate value of the target pattern at point B into the memory of the calibration unit 52.

Next, the chuck table 20 is rotated so that a straight line connecting the coordinate values of the target pattern at point A and the coordinate values of the target pattern at point B is parallel to the X-axis direction. Then, by moving the cutting unit 46 along the Y-axis direction, the amount of movement is the distance between the target pattern and the center line of the street S1, thereby completing the calibration of aligning the cutting tool 50 with the track S1 to be cut.

After the alignment of the first lane S1 is performed, the chuck table 20 is rotated by 90 degrees, and then the same operation is performed on the lane S2 to execute the alignment of the second lane S2.

When performing calibration, since no cutting fluid, swarf, or the like adheres to the wafer W held by the chuck table 20 , it is not necessary to supply water into the water-filled chamber 60 . In the imaging at the time of calibration by the imaging unit 54 of this embodiment, since the area to be cut of the wafer W is imaged by the CCD camera 74 in synchronization with the irradiation from the xenon flash lamp 70, even on the chucked table Even when the wafer W held at 20 is moving below the imaging unit 54, a still image can be captured. As a result, wafer W can be quickly imaged, and the time required for calibration can be shortened.

When the calibration is completed, the chuck table 20 is processed and fed in the X-axis direction by the X-axis feed mechanism 14, and the high-speed rotating cutting tool 50 is cut through the wafer W by a predetermined amount until the dicing tape T, thereby Cut the first spacer S1.

All the first streets S1 in the same direction are cut while the Y-axis feed mechanism 36 is driven to index-feed the cutting tool 50 . Next, the chuck table 20 is rotated by 90 degrees, and the second lane S2 perpendicular to the first lane S1 is cut.

When it is desired to confirm the state of the cutting groove during the cutting of the wafer W, that is, when it is desired to perform a notch inspection, the X-axis feed mechanism 14 is driven to position the wafer W held by the chuck table 20 on the Directly below the camera unit 54.

As shown in FIG. 5 , the on-off valve 66 is opened to supply water into the water filling chamber 60, and the chips and/or cutting fluid adhering to the wafer W are washed away with clean water, and the water is continuously supplied into the water filling chamber 60 while The xenon flash lamp 70 is turned on to illuminate the imaging region of the wafer W with strobe light.

Since an image is taken by the CCD camera 74 in synchronization with the light emission of the xenon flash lamp 70, a clear still image can be taken by the CCD camera 74 even when the chuck table 20 is moving.

The output of the CCD camera 74 is input to the monitor 76, and the cut groove 94 imaged is displayed on the monitor 76. The operator can observe the chips 96 and the like generated in the cut groove 94 while observing the image on the monitor 76 , and can confirm the state of the cut groove 94 .

When the generation ratio of chips 96 formed on both sides of the cutting flute 94 becomes large, it is judged that clogging of pores or the like has occurred in the cutting tool 50, and the operator performs replacement of the cutting tool 50 with a new cutting tool or the like. deal with.

In imaging during calibration by the imaging unit 54 of this embodiment, the CCD camera 74 images the area to be cut irradiated with an appropriate light amount in synchronization with the irradiation of the stroboscopic light from the xenon flash lamp 70. A still image can also be captured while the wafer W held by the chuck table 20 is moving below the imaging unit 54 . As a result, wafer W can be quickly imaged, and the time required for calibration can be shortened.

Moreover, when the notch inspection is performed, water is supplied into the water filling chamber 60, and the imaging area irradiated with an appropriate light quantity is captured by the CCD camera 74 in synchronization with the light emission of the xenon flash lamp 70. Therefore, even if the chuck operates Even when the table 20 is moving, still images can be captured by the CCD camera 74 . Therefore, the notch inspection can be performed quickly, and even if the notch inspection is performed, the decrease in productivity can be suppressed.

In the above-mentioned embodiment, the example of applying the imaging unit 54 of the present invention to the cutting device 2 has been described, but the present invention is not limited thereto, and the imaging unit 54 of the present invention can also be applied to other processing such as laser processing devices. device.

Claims (1)

1. A processing device comprising: a chuck table for holding an object to be processed; a processing member for holding a workpiece held on the chuck table; processing the workpiece; imaging means for imaging the workpiece held on the chuck table; and a processing feeding means for feeding the chuck The table and the processing member are processed and fed oppositely, and the processing device is characterized in that The camera components include: A strobe light source consisting of a xenon flash lamp for illuminating the workpiece; a camera configured to take an image of the illuminated workpiece in synchronization with the light emission of the stroboscopic light source; a beam splitter for reflecting a portion of the light from the stroboscopic light source and directing it to the workpiece; and a light quantity adjuster, the light quantity adjuster is disposed between the strobe light source and the beam splitter, and is used to adjust the light quantity of the light irradiated from the strobe light source, The light quantity adjuster includes: a rotating plate having an axis of rotation; an opening formed on the rotating plate for transmitting the light irradiated from the stroboscopic light source; The rotation angle correspondingly makes the amount of light passing through the opening continuously change between a maximum value and a minimum value; and a pulse motor connected to the rotating shaft, The workpiece is imaged by the video camera while the light shielding plate is rotated by the pulse motor, and the captured image is observed on a monitor so that the light intensity from the xenon strobe lamp is optimal. stop the driving of the pulse motor, Thereby, the light quantity from the xenon strobe lamp is adjusted to a light quantity suitable for imaging the workpiece by the light quantity adjuster, and an image of a region to be processed of the workpiece is imaged.