Method for adjusting brightness of illuminator in processing apparatus

Abstract

The present invention provides a method for adjusting the brightness of illuminators in a processing apparatus, which reduces the brightness difference between illuminators. In a first processing apparatus, a storage device stores a sample image obtained by photographing a specified pattern of a workpiece with the brightness of an illuminator specified by a first control value together with the first control value, and copies and stores it together with processing conditions in a storage device of a second processing apparatus. In the second processing apparatus, the storage device stores a plurality of comparison images obtained by photographing the specified pattern of the workpiece with the brightness of the illuminator specified by a plurality of different control values, compares the sample image with the plurality of comparison images, determines the control value when photographing the comparison image with the smallest difference in brightness and darkness relative to the sample image as the second control value, and sets the difference between the second control value and the first control value as a correction value of the control value of the second processing apparatus relative to the first processing apparatus in the second processing apparatus.

Description

Technical Field

[0001] The present invention relates to an adjustment method for adjusting the brightness of an illuminator in a processing apparatus having a camera unit for photographing a workpiece and a processing unit for processing the workpiece, the camera unit having the illuminator. Background Art

[0002] There are known processing apparatuses for processing workpieces such as semiconductor wafers having various patterns such as circuits and devices formed on one surface side. As the processing apparatus, for example, there is a cutting apparatus that cuts a workpiece along a dicing line (street) set on one surface side of the workpiece, or a laser processing apparatus that processes a workpiece by scanning the focal point of a laser beam along the dicing line.

[0003] When processing a workpiece along a dicing line, first, a camera disposed above the workpiece is used to photograph one surface side of the workpiece. Then, by performing image processing such as edge detection on the obtained image, the position of a specified pattern (so-called key pattern) provided on one surface side is determined, and the position of the dicing line is calculated using the position of the key pattern.

[0004] In addition, after processing the workpiece along the dicing line, image processing is performed on the image obtained by photographing one surface side of the workpiece, thereby checking the position, range, state, etc. of the cutting groove formed by cutting or the laser processing mark formed by laser processing.

[0005] The camera mounted on the processing apparatus has an objective lens and an illuminator (for example, refer to Patent Document 1). As the illuminator, a coaxial epi-illumination unit that irradiates light along the optical axis of the objective lens to one surface side of the workpiece, or a side-illumination unit that irradiates light along a direction inclined with respect to the optical axis of the objective lens to one surface side of the workpiece is used.

[0006] When photographing one surface side of the workpiece, photographing is performed after appropriately adjusting the light amount of the coaxial epi-illumination unit and the light amount of the side-illumination unit using a dimmer. There are various control methods as the dimming method, for example, a phase control method is adopted.

[0007] In the case of performing dimming by a phase control method, the dimmer has, for example: a semiconductor element that can electrically connect an AC power supply to a light source such as a halogen lamp; and a control circuit that supplies a specified signal to the semiconductor element to conduct current in the semiconductor element, thereby controlling the energization time of the light source.

[0008] A dimming signal showing a control value of the energization amount of a specified light source is input to the control circuit. The light amount of each lighting unit is adjusted by adjusting the energization amount of the light source. In addition, when using an LED (Light Emitting Diode) as the light source, the light amount is sometimes adjusted by adjusting the voltage applied to the LED.

[0009] By appropriately adjusting the light amount of the light sources of each lighting unit, when performing image processing on an image obtained by shooting, it is easy to identify key patterns, cutting grooves, laser processing marks, etc. Even if the light amount of the light source of the coaxial epi-illumination unit and the light amount of the light source of the side-illumination unit differ by only a few percent, there are significant differences in the results of image processing. Therefore, the light amount of each light source is an important shooting condition.

[0010] However, in the case where there are multiple processing devices of the same type, multiple processing devices are often used to process multiple workpieces of the same type. In this case, shooting conditions such as control values and processing conditions when processing the workpiece are copied from the first processing device to the second processing device.

[0011] As a result, in the second processing device, the workpiece is shot, processed, etc. under the same conditions as the first processing device. However, in a processing device, sometimes the brightness of the light source decreases due to deterioration of the light source or dirt adhering to the light source (for example, refer to Patent Document 2).

[0012] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-11641

[0013] Patent Document 2: Japanese Patent Application Laid-Open No. 2003-319253

[0014] For example, in the case where the performance of the light source of the second processing device deteriorates, even if a dimming signal showing the same control value as the control value used in the first processing device is input to the dimmer of the second processing device, an image with different shades and brightness compared to the image obtained by the first processing device will be obtained in the second processing device.

[0015] In this case, in the second processing device, there may be problems in the indexing at the position of the dividing line or the inspection of the position, range, state, etc. of the cutting groove, laser processing mark, etc. Summary of the Invention

[0016] The present invention has been completed in view of the above problems, and its object is to reduce the difference in brightness between illuminators in multiple processing devices.

[0017] According to one aspect of the present invention, there is provided a method for adjusting the brightness of an illuminator in a processing apparatus. The method for adjusting the brightness of the illuminator in the processing apparatus includes the following steps: a first storage step, in a first processing apparatus among a plurality of processing apparatuses each having a camera unit, a processing unit, and a storage device, the storage device of the first processing apparatus stores a sample image obtained by photographing a predetermined pattern provided on a workpiece at the brightness of the illuminator specified by a first control value together with the first control value. The camera unit includes the illuminator whose brightness can be adjusted, an objective lens, and an imaging element, and photographs the workpiece by causing the reflected light of the light irradiated from the illuminator to the workpiece to enter the imaging element via the objective lens. The processing unit processes the workpiece based on the image obtained by the camera unit, and the storage device stores a control value specifying the brightness of the illuminator and the processing conditions of the processing unit when processing the workpiece; a copying step, copying the sample image and the first control value stored in the storage device of the first processing apparatus together with the processing conditions used in the first processing apparatus, and storing them in the storage device of the second processing apparatus; a second storage step, in the second processing apparatus, the storage device of the second processing apparatus stores a plurality of comparison images obtained by photographing the predetermined pattern of the workpiece at the brightness of the illuminator specified by a plurality of different control values; a control value determination step, comparing the sample image with the plurality of comparison images, and determining the control value when the comparison image with the smallest difference in brightness and darkness with respect to the sample image is photographed as the second control value; and a correction value setting step, setting the difference between the second control value and the first control value as a correction value of the control value of the second processing apparatus with respect to the first processing apparatus in the second processing apparatus.

[0018] Preferably, in the control value determination step, at each same position in the longitudinal and lateral directions of the sample image and each comparison image, a numerical difference indicating the degree of brightness of each pixel constituting the image is calculated, and the sum of the differences is compared.

[0019] In addition, preferably, the illuminator has: an axial epi-illumination unit that irradiates light along the optical axis of the objective lens; and a side-illumination unit that irradiates light inclined with respect to the optical axis of the objective lens. In the first storage step, the first control value includes a third control value and a fourth control value, the sample image includes a first sample image and a second sample image, the first sample image is obtained by photographing the specified pattern of the workpiece by only lighting the axial epi-illumination unit according to the third control value, the second sample image is obtained by photographing the specified pattern of the workpiece by only lighting the side-illumination unit according to the fourth control value, and the storage device of the first processing device stores the first sample image and the second sample image together with the third control value and the fourth control value. In the second storage step, the storage device of the second processing device stores a plurality of first comparison images and a plurality of second comparison images, the plurality of first comparison images are obtained by photographing the specified pattern of the workpiece by only lighting the axial epi-illumination unit according to a plurality of different control values respectively, the plurality of second comparison images are obtained by photographing the specified pattern of the workpiece by only lighting the side-illumination unit according to a plurality of different control values respectively. In the control value determination step, the second control value includes a fifth control value and a sixth control value, the first sample image is compared with each first comparison image, and the control value when the first comparison image with the smallest difference in brightness with respect to the first sample image is photographed is determined as the fifth control value, and the second sample image is compared with each second comparison image, and the control value when the second comparison image with the smallest difference in brightness with respect to the second sample image is photographed is determined as the sixth control value. In the correction value setting step, the difference between the fifth control value and the third control value is set as the first correction value of the control value of the second processing device with respect to the first processing device in the second processing device, and the difference between the sixth control value and the fourth control value is set as the second correction value of the control value of the second processing device with respect to the first processing device in the second processing device.

[0020] In the method for adjusting the brightness of the illuminator in a processing device according to an aspect of the present invention, first, the storage device of the first processing device stores the sample image obtained by photographing the specified pattern provided on the workpiece according to the brightness of the illuminator specified by the first control value together with the first control value (first storage step).

[0021] Next, the sample image and the first control value are copied together with the processing conditions and stored in the storage device of the second processing device (copying step). Then, in the second processing device, the storage device of the second processing device stores a plurality of comparison images obtained by photographing the specified pattern of the workpiece according to the brightness of the illuminator specified by a plurality of different control values (second storage step).

[0022] Then, the sample image and a plurality of comparison images are compared, and the control value when the comparison image with the smallest difference in brightness with respect to the sample image is taken is determined as the second control value (control value determination step). Then, the difference between the second control value and the first control value is set as the correction value of the control value of the second processing device with respect to the first processing device in the second processing device (correction value setting step).

[0023] Accordingly, if a dimming signal showing the same control value is input to the dimmers of the respective processing devices, the brightness of the illuminator of the second processing device can be corrected using the correction value. Therefore, even when deterioration of the light source or the like occurs in the second processing device, the difference in brightness between the illuminators can be reduced.

[0024] That is, the difference in brightness of the images obtained by the camera units of the respective processing devices can be reduced. In addition, the difference in the images obtained by the camera units of the respective processing devices can be reduced without replacing the light source or the like and without using a special test piece for measuring the difference in the amount of light of the camera units. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a perspective view showing an example of a cutting device.

[0026] Figure 2 (A) of is a diagram for explaining the camera unit, Figure 2 (B) of is a bottom view of the camera unit.

[0027] Figure 3 (A) of is a diagram showing a situation of photographing a workpiece, Figure 3 (B) of is a schematic diagram of the image obtained by this photographing.

[0028] Figure 4 (A) of is a diagram showing a situation of photographing with only the coaxial epi-illumination unit lit, Figure 4 (B) of is a schematic diagram of the image obtained by this photographing.

[0029] Figure 5 (A) of is a diagram showing a situation of photographing with only the side illumination unit lit, Figure 5 (B) of is a schematic diagram of the image obtained by this photographing.

[0030] Figure 6 is a diagram showing a plurality of cutting devices of the same type.

[0031] Figure 7 is a flowchart of the method for adjusting the brightness of the illuminator according to the first embodiment.

[0032] Figure 8 (A) is a schematic diagram of a sample image, Figure 8 (B) is a schematic diagram of a comparison image, Figure 8 (C) is a schematic diagram of a comparison image, Figure 8 (D) is a schematic diagram of a comparison image.

[0033] Figure 9 is a flowchart of a method for adjusting the brightness of the illuminator according to the second embodiment.

[0034] Reference Numeral Explanation

[0035] 2: Cutting device; 2a: First cutting device; 2b: Second cutting device; 2c: Third cutting device; 4: Base; 4a, 4b, 4e: Openings; 4c, 4d: Support bodies; 6a: Cassette elevator; 6b: Cassette; 10: Workbench cover; 11: Workpiece; 11a: Front surface; 11b: Rear surface; 11c: Key pattern; 12: Corrugated cover; 13: Dicing tape; 14: Chuck table; 14a: Holding surface; 15: Frame; 16: Fixture; 17: Workpiece unit; 18: Lower transfer unit; 20: Upper transfer unit; 22: Processing unit moving mechanism; 22a: Y-axis moving plate; 22b: Z-axis pulse motor; 24: Cutting unit; 26: Camera unit; 26a: Housing; 26b: Opening; 28: Imaging element; 30: Objective lens; 30a: Optical axis; 32: First light source; 36: Half mirror; 38: Coaxial epi-illumination unit; 40: Housing; 40a: Opening; 40b: Optical fiber; 42: Second light source; 44: Side illumination unit; 46: Dimmer; 48: Illuminator; 50: Control unit; 50a: Storage device; 52: Control value; 54: AC power supply; 56: Current waveform; 58: Correction value; 60: Cleaning unit; 62: Shooting conditions; 64: Processing conditions; 70: Sample image, First sample image; 72a, 72b, 72c: Comparison images; 80: Second sample image. Detailed Embodiment

[0036] An embodiment of one aspect of the present invention will be described with reference to the accompanying drawings. Figure 1 is a perspective view showing an example of a cutting device (processing device) 2 according to an embodiment of the present invention. In addition, in Figure 1 a part of the structural elements is shown by a functional block diagram.

[0037] In addition, Figure 1 the X-axis direction (processing feed direction), Y-axis direction (indexing feed direction), and Z-axis direction (vertical direction, height direction) in

[0038] An opening 4a is provided at the front corner of the base 4. A cassette elevator 6a that is lifted and lowered by a lifting mechanism (not shown) is provided within the opening 4a. A cassette 6b for accommodating a plurality of workpieces 11 is placed on the upper surface of the cassette elevator 6a.

[0039] The workpiece 11 is, for example, a disk-shaped wafer formed of a semiconductor material such as silicon. In addition, the material, shape, structure, size, etc. of the workpiece 11 are not limited. A plurality of dicing predetermined lines (scribe lanes) that intersect each other are set on the front 11a side of the workpiece 11.

[0040] Devices such as ICs (Integrated Circuits) are formed on the front 11a side of each region divided by the plurality of dicing predetermined lines. In addition, a key pattern 11c (see (B) etc. of Figure 3 ) is formed in the region where the devices are formed.

[0041] The key pattern 11c is, for example, a region where the metal layer is exposed on the front 11a side as a result of partially removing the insulating layer in a stacked structure having a metal layer and an insulating layer formed on the metal layer. However, the structure of the key pattern 11c is not limited to this example.

[0042] A dicing tape (adhesive tape) 13 having a diameter larger than that of the workpiece 11 is pasted on the back 11b of the workpiece 11 on the side opposite to the front 11a. One surface of a metal ring-shaped frame 15 is pasted on the outer peripheral portion of the dicing tape 13.

[0043] The workpiece 11 is accommodated in the cassette 6b in the state of the workpiece unit 17 supported by the frame 15 via the dicing tape 13. In addition, a plurality of workpiece units 17 are accommodated in the cassette 6b.

[0044] A rectangular opening 4b having a long side along the X-axis direction is formed on the side of the cassette elevator 6a. A worktable cover 10 and a corrugated cover 12 that expands and contracts in the X-axis direction are provided within the opening 4b.

[0045] A chuck worktable 14 is provided on the worktable cover 10. In addition, a rotation drive source such as a motor (not shown) is disposed below the worktable cover 10, and the rotation drive source is used to rotate the chuck worktable 14 about a rotation axis substantially parallel to the Z-axis direction (vertical direction).

[0046] A ball screw type X-axis moving mechanism (processing feed unit) (not shown) is provided below the rotation drive source. By operating the X-axis moving mechanism, the chuck worktable 14 and the worktable cover 10 move along the X-axis direction.

[0047] The chuck table 14 has a disk-shaped frame made of metal. A disk-shaped recess is formed in the frame. A suction path (not shown) is formed at the bottom of the recess. One end of the suction path is exposed on the bottom surface of the recess, and the other end of the suction path is connected to a suction source (not shown) such as an ejector.

[0048] A disk-shaped porous plate is fixed in the recess. The upper surface of the porous plate is substantially flat, and when the suction source is operated, a negative pressure is generated on the upper surface (holding surface 14a) of the porous plate. In addition, a jig 16 for fixing the frame 15 is provided around the frame.

[0049] A pair of guide rails (not shown) substantially parallel to the Y-axis direction are provided in a region of the opening 4b adjacent to the opening 4a. In the X-axis direction, a gantry-shaped support 4c is provided across the opening 4b at a position inside the cutting device 2 relative to the pair of guide rails.

[0050] A lower transfer unit 18 and an upper transfer unit 20 for transferring the workpiece unit 17 are provided on one surface side of the support 4c. The lower transfer unit 18 and the upper transfer unit 20 each have a plurality of suction pads for sucking and holding the workpiece unit 17 by negative pressure.

[0051] A gantry-shaped support 4d is provided across the opening 4b on the opposite side of the lower transfer unit 18 and the upper transfer unit 20 with respect to the support 4c. A pair of processing unit moving mechanisms (indexing feed unit, plunge feed unit) 22 are provided on the front side of the support 4d.

[0052] The pair of processing unit moving mechanisms 22 have a pair of Y-axis guide rails (not shown) disposed on the front of the support 4d and substantially parallel to the Y-axis direction. Two Y-axis moving plates 22a are mounted on the pair of Y-axis guide rails so as to be slidable in the Y-axis direction.

[0053] A nut portion (not shown) is provided on the back surface (i.e., the support 4d) side of each Y-axis moving plate 22a, and a Y-axis ball screw (not shown) substantially parallel to the Y-axis guide rail is rotatably connected to the nut portion.

[0054] A Y-axis pulse motor (not shown) is connected to one end of each Y-axis ball screw. If the Y-axis ball screw is rotated by the Y-axis pulse motor, each Y-axis moving plate 22a moves along the Y-axis guide rail.

[0055] A Z-axis guide rail (not shown) substantially parallel to the Z-axis direction is provided on the front surface (i.e., the support 4c) side of each Y-axis moving plate 22a. A Z-axis moving plate (not shown) is slidably mounted on the Z-axis guide rail.

[0056] On the back side of the Z-axis moving plate (i.e., the support body 4d), a nut portion (not shown) is provided, and a Z-axis ball screw (not shown) parallel to the Z-axis guide rail is rotatably connected to the nut portion.

[0057] One end of the Z-axis ball screw (not shown) is connected to a Z-axis pulse motor 22b. If the Z-axis ball screw is rotated by the Z-axis pulse motor 22b, the Z-axis moving plate moves in the Z-axis direction along the Z-axis guide rail.

[0058] On each Z-axis moving plate, a cutting unit (processing unit) 24 for cutting (processing) the workpiece 11 is provided. In the present embodiment, a pair of cutting units 24 are arranged along the Y-axis direction.

[0059] The cutting unit 24 has a cylindrical spindle housing. A spindle (not shown) arranged substantially parallel to the Y-axis direction is partially accommodated in the spindle housing. The spindle is rotatably supported within the spindle housing.

[0060] One end of the spindle is connected to a rotation drive source such as a servo motor (not shown). In addition, a cutting tool having an annular cutting edge is mounted at the other end of the spindle. A camera unit 26 for photographing the workpiece 11 is provided at a position adjacent to the cutting unit 24.

[0061] Here, with reference to Figure 2 (A) of Figure 2 and Figure 2 (B) of Figure 2 the camera unit 26 will be described. Figure 2 (A) of

[0062] is a diagram for explaining the camera unit 26. In addition, in

[0063] (A) of

[0064] The camera unit 26 has a cylindrical housing 26a arranged substantially parallel to the Z-axis direction. A photographing element 28 such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor is fixed to the upper end portion of the housing 26a.

[0063] An objective lens 30 is fixed to the lower end portion of the housing 26a such that the optical axis 30a is substantially parallel to the Z-axis direction. The housing 26a, the photographing element 28, and the objective lens 30 constitute a camera. The workpiece 11 whose back surface 11b side is held by the holding surface 14a is arranged below the objective lens 30.

[0064] An opening 26b is provided on the side of the housing 26a, and a substantially cylindrical housing is arranged to cover the opening 26b. A first light source 32 such as a halogen lamp is provided inside the housing. The light emitted by the first light source 32 enters the inside of the housing 26a through the opening 26b.

[0065] A half mirror 36 is arranged between the imaging element 28 and the objective lens 30 in a state where its surface is inclined at approximately 45 degrees with respect to the optical axis 30a of the objective lens 30. A part of the light entering the inside of the housing 26a from the opening 26b is reflected by the half mirror 36 and travels downward along the optical axis 30a of the objective lens 30.

[0066] The light reflected by the half mirror 36 passes through the objective lens 30 and irradiates the front surface 11a of the workpiece 11. The light (reflected light) reflected on the front surface 11a side enters the imaging element 28 through the objective lens 30, the half mirror 36, and an imaging lens (not shown).

[0067] In this way, when using the coaxial epi-illumination unit 38 composed of the objective lens 30, the first light source 32, the half mirror 36, etc., it is possible to photograph the front surface 11a side using the light irradiated along the optical axis 30a to the front surface 11a side.

[0068] A circular ring-shaped housing 40 is arranged on the side of the lower end of the housing 26a. A plurality of openings 40a are formed on the bottom surface of the housing 40. The plurality of openings 40a are arranged at substantially equal intervals along the outer peripheral direction of the bottom surface of the housing 40.

[0069] One end of an optical fiber 40b is fixed in each opening. The other end of the optical fiber 40b is connected to a second light source 42 such as a halogen lamp arranged outside the housing 40. The light emitted by the second light source 42 irradiates downward radially from one end of the optical fiber 40b.

[0070] The light incident on the front surface 11a side from one end of the optical fiber 40b at a specified incident angle is reflected from the front surface 11a side at a specified reflection angle and enters the imaging element 28 through the objective lens 30 and the half mirror 36.

[0071] In this way, when using the side illumination unit 44 composed of the housing 40, the optical fiber 40b, the second light source 42, etc., it is possible to photograph the front surface 11a side of the workpiece 11 in a state where the light irradiated obliquely with respect to the optical axis 30a is irradiated obliquely with respect to the front surface 11a.

[0072] The first light source 32 and the second light source 42 are respectively connected to a dimmer 46, and the dimmer 46 adjusts the light amount (brightness) by adjusting the power supply amount to each light source. In addition, in the present embodiment, the coaxial epi-illumination unit 38, the side illumination unit 44, and the dimmer 46 are collectively referred to as an illuminator 48.

[0073] The dimmer 46 is connected to a control unit 50 that controls the operation of the dimmer 46. In addition, the control unit 50 also controls the operations of the cassette elevator 6a, the suction source, the X-axis moving mechanism, a pair of processing unit moving mechanisms 22, the cutting unit 24, the lower conveying unit 18, the upper conveying unit 20, the imaging element 28, the cleaning unit 60 (described later), and the like.

[0074] The control unit 50 is constituted by, for example, a computer that includes processing devices such as a processor typified by a CPU (Central Processing Unit), main storage devices such as a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), and a ROM (ReadOnly Memory), and auxiliary storage devices such as a flash memory, a hard disk drive, and a solid state drive.

[0075] Software including a prescribed program is stored in the auxiliary storage device. By operating the processing devices and the like in accordance with this software, the functions of the control unit 50 are realized. In addition, the processing device may be constituted by an ASIC (ApplicationSpecific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or the like.

[0076] At least a part of the auxiliary storage device functions as a storage device 50a (see Figure 1 ), and the storage device 50a stores the processing conditions (such as the rotation speed of the main shaft, the flow rate of the cutting water, and the moving speed of the chuck table 14) when the workpiece 11 is cut by the cutting unit 24.

[0077] The storage device 50a also stores imaging conditions including a control value (described later) specifying the energization amount of the dimmer 46, images taken by the camera unit 26, and the like. Here, a method of controlling the dimmer 46 in a phase control manner using the control unit 50 to adjust the brightness of the illuminator 48 will be described.

[0078] The dimmer 46 has, for example: a first semiconductor element (such as a triac) (not shown) that switches the conduction and non-conduction between the AC power supply 54 and the first light source 32; and a first control circuit (not shown) that controls the operation of the first semiconductor element.

[0079] In addition, the dimmer 46 includes: a second semiconductor element (e.g., a triac) (not shown) that switches conduction and non-conduction between the AC power supply 54 and the second light source 42; and a second control circuit (not shown) that controls the operation of the second semiconductor element.

[0080] A dimming signal is sent from the control unit 50 to the first and second control circuits. The dimming signal indicates a control value 52 that respectively specifies the amount of power conducted from the AC power supply 54 to the first light source 32 and the second light source 42. By specifying the amount of power conducted, the light amount of each light source is specified.

[0081] The control value 52 in the present embodiment is a value corresponding to the time from the start time of a half-cycle of the AC current to the time when the first light source 32 and / or the second light source 42 is energized by inputting a gate signal to the semiconductor element.

[0082] When a gate signal is input to the semiconductor element, the first light source 32 and / or the second light source 42 is energized, and the first light source 32 and / or the second light source 42 is energized from the energized time to the end time of a half-cycle of the AC current. The first light source 32 and the second light source 42 become brighter in proportion to the energization time.

[0083] A dimming signal indicating a control value 52 that specifies the amount of power conducted to the first light source 32 and the second light source 42 as 50% is input to the control circuit. In this case, when the half-cycle of the AC current output from the AC power supply 54 is set to T / 2, as shown by the current waveform 56, the first light source 32 and the second light source 42 are energized during the period from T / 4 to T / 2. Such energization control is repeated every half-cycle.

[0084] In addition, for example, when a dimming signal indicating a control value 52 that specifies the amount of power conducted to the first light source 32 and the second light source 42 as 0% is input to the control circuit, a gate signal is input to the first and second semiconductor elements at the timing of the start time of T / 2. In this case, the first light source 32 and the second light source 42 are hardly energized. Such energization control is repeated every half-cycle.

[0085] Figure 3 (A) shows a situation where the front surface 11a side of the workpiece 11 held on the holding surface 14a on the back surface 11b side is photographed using both the coaxial epi-illumination unit 38 and the side-illumination unit 44. Figure 3 (B) is a schematic diagram of the image obtained by this photographing.

[0086] The control value 52 can individually specify the light amounts of the first light source 32 and the second light source 42. In Figure 3In (A) thereof, the power supply amount of the first light source 32 constituting the coaxial epi-illumination unit 38 is set to 20%, and the power supply amount of the second light source 42 constituting the side illumination unit 44 is set to 20%. In Figure 3 In the image shown in (B) thereof, the key pattern 11c is photographed relatively well.

[0087] The key pattern 11c of the present embodiment is a cross-shaped region, and an image including the key pattern 11c is used, for example, when aligning the division line of the workpiece 11 with the position of the cutting tool of the cutting unit 24.

[0088] Figure 4 (A) thereof is a view showing a case where only the coaxial epi-illumination unit 38 is lit to photograph the front surface 11a side. Figure 4 (B) thereof is a schematic view of an image obtained by photographing by only lighting the coaxial epi-illumination unit 38.

[0089] In Figure 4 (A) thereof, the power supply amount of the first light source 32 is set to 20%, and the power supply amount of the second light source 42 is set to 0%. In Figure 4 In the image shown in (B) thereof, compared with the image of Figure 3 (B) thereof, the unevenness on the front surface 11a side is photographed more clearly.

[0090] Figure 5 (A) thereof is a view showing a case where only the side illumination unit 44 is lit to photograph the front surface 11a side. Figure 5 (B) thereof is a schematic view of an image obtained by photographing by only lighting the side illumination unit 44.

[0091] In Figure 5 (A) thereof, the power supply amount of the first light source 32 is set to 0%, and the power supply amount of the second light source 42 is set to 20%. In Figure 5 In the image shown in (B) thereof, compared with the image of Figure 3 (B) thereof, the contrast of the whole image is reduced.

[0092] Here, returning again to Figure 1 , other structural elements of the cutting device 2 will be described. An opening 4e is provided at a position on the side opposite to the opening 4a with respect to the opening 4b. A cleaning unit 60 for cleaning the processed workpiece 11 is provided in the opening 4e.

[0093] The cleaning unit 60 has a rotary table that rotates while holding the workpiece unit 17. A nozzle is disposed above the rotary table, and the nozzle sprays a gas-liquid mixture of pure water and air toward the rotary table.

[0094] However, in a factory where multiple cutting devices 2 of the same type are provided, multiple cutting devices 2 are often used to process multiple workpieces 11 of the same type. Figure 6 FIG. is a view showing multiple cutting devices (processing devices) 2 of the same type.

[0095] In order to simultaneously process the workpiece 11 using multiple cutting devices 2, shooting conditions 62 including control values 52, processing conditions 64, etc. are copied from the first cutting device 2a to the second cutting device 2b, the third cutting device 2c, etc.

[0096] As a result, in the second cutting device 2b, etc., the workpiece 11 is shot, processed, etc. under the same shooting conditions 62 and processing conditions 64 as those of the first cutting device 2a. However, for example, sometimes the brightness of the illuminator 48 of the second cutting device 2b decreases due to deterioration of the first light source 32, etc. in the second cutting device 2b.

[0097] In this case, even if a dimming signal showing the same control value 52 is input to the first cutting device 2a and the second cutting device 2b, in the second cutting device 2b, an image with different shades and brightness compared to the first cutting device 2a is obtained.

[0098] As a result, in the second cutting device 2b, there may be a problem in the inspection of the position, range, state, etc. of the indexing or cutting groove, etc. at the position of the division line. Therefore, in the present embodiment, by comparing the images with the brightness of the illuminator 48 adjusted, the brightness of the illuminator 48 is adjusted to absorb the difference between the illuminators 48.

[0099] Figure 7 FIG. is a flowchart of a method for adjusting the brightness of the illuminator 48 according to the first embodiment. In addition, in the present embodiment, a method for adjusting the brightness of the illuminator 48 in the first cutting device 2a and the second cutting device 2b is described, but the brightness of the illuminator 48 can also be adjusted in three or more cutting devices 2.

[0100] In the present embodiment, first, a first storage step S10 is performed. In the first storage step S10, a dimming signal showing the first control value 52a is input to the dimmer 46 of the first cutting device 2a, the illuminator 48 is made to have a specified brightness, and the key pattern 11c on the front surface 11a side of the workpiece 11 is shot to obtain a sample image 70 (refer to Figure 8 of (A)).

[0101] Figure 8 of (A) is a schematic view of the sample image 70. In Figure 8In (A) of, according to the first control value 52a, only the coaxial epi-illumination unit 38 is lit in such a way that the energization amount of the first light source 32 becomes 20% and the energization amount of the second light source 42 becomes 0% to obtain the sample image 70.

[0102] Then, the storage device 50a of the first cutting device 2a stores the sample image 70 together with the first control value 52a. After the first storage step S10, the copying step S20 is performed.

[0103] In the copying step S20, the sample image 70 stored in the storage device 50a of the first cutting device 2a, the shooting conditions 62 including the first control value 52a, and the processing conditions 64 used in the first cutting device 2a are copied and stored in the storage device 50a of the second cutting device 2b.

[0104] The first cutting device 2a and the second cutting device 2b are connected to each other, for example, by wire or wirelessly. In this case, in the copying step S20, information such as the sample image 70, the shooting conditions 62 including the first control value 52a, and the processing conditions 64 is sent from the first cutting device 2a to the second cutting device 2b via wire or wirelessly.

[0105] In addition, the first cutting device 2a and the second cutting device 2b may not be connected to each other by wire or wirelessly. In this case, the first cutting device 2a and the second cutting device 2b have a writing / reading device (not shown), which writes information to a recording medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), a USB (Universal Serial Bus) memory, a magnetoresistive memory, etc., and further reads information from the recording medium.

[0106] After the operator records information such as the sample image 70, the shooting conditions 62 including the first control value 52a, and the processing conditions 64 in the recording medium, the writing / reading device of the second cutting device 2b reads the recording medium. Thus, this information is copied from the first cutting device 2a to the second cutting device 2b.

[0107] After the copying step S20, in the second cutting device 2b, a plurality of comparison images are obtained by photographing the key pattern 11c on the front 11a side with the brightness of the illuminator 48 specified by different multiple control values 52 (refer to Figure 8 of (B), Figure 8 of (C), Figure 8 of (D)).

[0108] Specifically, a plurality of control values 52 that respectively specify an energization amount smaller than the energization amount corresponding to the first control value 52a, the same energization amount, and a larger energization amount are used to photograph the key pattern 11c, and a plurality of comparison images are obtained.

[0109] In addition, in the present embodiment, by adjusting the energization amount of the second light source 42 to 0% and adjusting the energization amount of the first light source 32 to various ratios greater than 0%, a comparison image is obtained by illuminating only the coaxial epi-illumination unit 38.

[0110] For example, in the second cutting device 2b, the key pattern 11c is photographed with a control value 52-1 in which the energization amount of the first light source 32 is set to 16% and the energization amount of the second light source 42 is set to 0%. In addition, the key pattern 11c is photographed with a control value 52-2 in which the energization amount of the first light source 32 is set to 18% and the energization amount of the second light source 42 is set to 0%.

[0111] Furthermore, in the second cutting device 2b, the key pattern 11c is photographed with a control value 52-3 in which the energization amount of the first light source 32 is set to 20% and the energization amount of the second light source 42 is set to 0%. In addition, the key pattern 11c is photographed with a control value 52-4 in which the energization amount of the first light source 32 is set to 22% and the energization amount of the second light source 42 is set to 0%.

[0112] In addition, in the second cutting device 2b, the key pattern 11c is photographed with a control value 52-5 in which the energization amount of the first light source 32 is set to 24% and the energization amount of the second light source 42 is set to 0%. The storage device 50a of the second cutting device 2b stores the plurality of comparison images obtained in this way (second storage step S30).

[0113] Figure 8 (B) is a schematic diagram of the comparison image 72a obtained by photographing the key pattern 11c with the control value 52-3.

[0114] Figure 8 (C) is a schematic diagram of the comparison image 72b obtained by photographing the key pattern 11c with the control value 52-4.

[0115] Figure 8 (D) is a schematic diagram of the comparison image 72c obtained by photographing the key pattern 11c with the control value 52-5. In addition, the comparison image obtained by photographing with the control value 52-1 and the comparison image obtained by photographing with the control value 52-2 are omitted.

[0116] After the second storage step S30, the sample image 70 is compared with the comparison images 72a, 72b, and 72c. In the present embodiment, between the sample image 70 and each of the comparison images 72a, 72b, and 72c being compared, the sum N of the numerical differences indicating the degrees of brightness of the respective pixels constituting the image P is compared.

[0117] The numerical value indicating the degree of brightness refers to, for example, the pixel value represented by 8 bits (i.e., 256 gradations) in the case where the image is a grayscale image. When the color of the pixel is black, the pixel value is set to zero, and when the color of the pixel is white, the pixel value is set to 255. Of course, the image is not limited to a grayscale image and may also be a color image.

[0118] The sample image 70 and each of the comparison images 72a, 72b, and 72c are images having the same number of pixels in the vertical and horizontal directions. For example, when calculating the sum N of the differences in pixel values between the sample image 70 and the comparison image 72a P in the sample image 70 and the comparison image 72a, after calculating the differences in pixel values of the respective pixels at the same positions in the vertical and horizontal directions (i.e., the same coordinate positions), the sum of these differences is calculated.

[0119] In the present embodiment, the sum N of the differences in pixel values of the respective pixels at the same coordinate positions between the sample image 70 and the comparison image 72b P2 is smaller than the sum N of the differences in pixel values of the respective pixels at the same coordinate positions between the sample image 70 and the comparison image 72a P1 is small.

[0120] In addition, the sum N P2 is smaller than the sum N of the differences in pixel values of the respective pixels at the same coordinate positions between the sample image 70 and the comparison image 72c P3 is small. Thus, the sum N P2 is the smallest. That is, the difference in light and dark between the sample image 70 and the comparison image 72b is the smallest.

[0121] The control unit 50 of the second cutting device 2b determines the control value 52-4 when the comparison image 72b having the smallest difference in light and dark with respect to the sample image 70 is captured as the second control value 52b according to a predetermined program stored in its auxiliary storage device (control value determination step S40).

[0122] After the control value determination step S40, the control unit 50 of the second cutting device 2b sets the difference between the second control value 52b and the first control value 52a as the correction value 58 of the control value 52 of the second cutting device 2b with respect to the first cutting device 2a (correction value setting step S50).

[0123] The first control value 52a determines the energization start timing of the first light source 32 of the first cutting device 2a. The first control value 52a is, for example, a value corresponding to the time from the start time of the half cycle T / 2 of the alternating current to the time t1.

[0124] When a dimming signal indicating the first control value 52a is input to the dimmer 46 of the first cutting device 2a, the first light source 32 of the first cutting device 2a is energized from the time t1 to the end time of the half cycle T / 2. In this case, the energization amount of the coaxial epi-illumination unit 38 of the first cutting device 2a is, for example, 20%.

[0125] The second control value 52b determines the energization start timing of the first light source 32 of the second cutting device 2b. The second control value 52b is, for example, a value corresponding to the time from the start time of the half cycle T / 2 of the alternating current to the time t2 earlier than the time t1.

[0126] When a dimming signal indicating the second control value 52b is input to the dimmer 46 of the second cutting device 2b, it is energized from the time t2 to the end time of the half cycle T / 2. In this case, the energization amount of the coaxial epi-illumination unit 38 of the second cutting device 2b is, for example, 22%.

[0127] The difference between the time t2 and the time t1 corresponds to the difference in energization amount, and as a value corresponding to this difference in energization amount, a correction value 58 is determined. In the correction value setting step S50, for example, the control unit 50 of the second cutting device 2b automatically stores the correction value 58 in its own storage device 50a. Alternatively, the correction value 58 may be stored in the storage device 50a of the second cutting device 2b according to an operator's instruction, input, etc.

[0128] When machining the workpiece 11 using the second cutting device 2b, a dimming signal indicating the second control value 52b obtained by adding the correction value 58 to the first control value 52a is input to the dimmer 46 of the second cutting device 2b.

[0129] In this way, the energization amount of the illuminator 48 of the second cutting device 2b, that is, the light amount (brightness) of the illuminator 48 of the second cutting device 2b is corrected. Therefore, even when light source deterioration or the like occurs, the difference in brightness between the illuminators 48 can be reduced.

[0130] That is, the difference in brightness of the images obtained by the camera units 26 of the first cutting device 2a and the second cutting device 2b can be reduced. In addition, there is also the following advantage: the difference in the images obtained by the respective camera units 26 can be reduced without replacing the light source or the like and without using a special test piece for measuring the difference in the light amount of the camera units 26.

[0131] Next, a general procedure for cutting (processing) the workpiece 11 using the cutting device 2 will be described. When cutting the workpiece 11, first, the workpiece unit 17 is pulled out from the pair of guide rails by the push-pull arm of the lower conveying unit 18.

[0132] By moving the pair of guide rails closer to each other in the X-axis direction, the position of the workpiece unit 17 in the X-axis direction is adjusted. Next, the workpiece unit 17 is conveyed from the pair of guide rails to the chuck table 14 by the lower conveying unit 18.

[0133] After attracting and holding the back surface 11b side using the holding surface 14a, a dimming signal showing the control value 52 is input into the dimmer 46. Thereby, the illuminator 48 is made to have a prescribed brightness, and the front surface 11a side is photographed using the camera unit 26. In addition, when it is necessary to adjust the brightness of the illuminator 48, the brightness of the illuminator 48 is adjusted using the above-described correction value 58.

[0134] The control unit 50 performs prescribed image processing (i.e., based on the image) on the image obtained by photographing, thereby determining the position of the key pattern 11c. Then, based on the position of the key pattern 11c, the position, orientation, etc. of the division predetermined line arranged at a predetermined position are determined.

[0135] After adjusting the orientation of the chuck table 14 using the rotation drive source so that the orientation of the division predetermined line is parallel to the X-axis direction, while relatively moving the cutting tool and the chuck table 14 in the X-axis direction, the workpiece 11 is cut according to the prescribed processing conditions 64.

[0136] After cutting the workpiece 11 along all the division predetermined lines, the workpiece unit 17 is conveyed from the chuck table 14 to the cleaning unit 60 by the upper conveying unit 20, and the workpiece 11 is cleaned and dried using the cleaning unit 60.

[0137] Then, after conveying the workpiece unit 17 from the cleaning unit 60 to the pair of guide rails using the lower conveying unit 18, the workpiece unit 17 is pushed into the cassette 6b from the pair of guide rails using the push-pull arm of the lower conveying unit 18.

[0138] Next, a description will be given of the second embodiment. Figure 9 It is a flowchart of the method for adjusting the brightness of the illuminator 48 in the second embodiment. In the second embodiment as well, first, the first storage step S10 is performed. However, in the first storage step S10, the operation of the dimmer 46 is adjusted so as to individually light the first light source 32 and the second light source 42 at individual locations in the first cutting device 2a.

[0139] For example, when a dimming signal showing the third control value 52c is input to the dimmer 46, the illuminator 48 is lit in such a way that the power consumption of the first light source 32 is 20% and the power consumption of the second light source 42 is 0%. Thus, only the coaxial epi-illumination unit 38 is lit to obtain the first sample image 70.

[0140] Then, when a dimming signal representing the fourth control value 52d is input to the dimmer 46, the illuminator 48 is lit in such a way that the power consumption of the first light source 32 is 0% and the power consumption of the second light source 42 is 20%. Thus, only the side-illumination unit 44 is lit to photograph the key pattern 11c, thereby obtaining the second sample image 80 (refer to Figure 5 (B) of

[0141] Then, the storage device 50a of the first cutting device 2a stores the first sample image 70 and the second sample image 80 together with the third control value 52c and the fourth control value 52d (the first storage step S10). Next, the first sample image 70, the second sample image 80, the photographing conditions 62 including the third control value 52c and the fourth control value 52d, and the processing conditions 64 are copied and stored in the storage device 50a of the second cutting device 2b (the copying step S20).

[0142] After the copying step S20, the second storage step S30 is performed. However, in the second storage step S30 of the second embodiment, a plurality of first comparison images are obtained by photographing the key pattern 11c by only lighting the coaxial epi-illumination unit 38, and a plurality of second comparison images are obtained by photographing the key pattern 11c by only lighting the side-illumination unit 44.

[0143] When obtaining a plurality of first comparison images and a plurality of second comparison images, similar to the first embodiment, the key pattern 11c is photographed by respectively specifying a plurality of control values 52 of the power consumption smaller than the power consumption corresponding to the third control value 52c and the fourth control value 52d, the same power consumption, and the larger power consumption.

[0144] Then, the storage device 50a of the second cutting device 2b stores the plurality of first comparison images and the plurality of second comparison images (the second storage step S30). After the second storage step S30, the control value determination step S40 is performed.

[0145] In the control value determination step S40 of the second embodiment, the control unit 50 of the second cutting device 2b calculates the sum N of the differences in pixel values of each pixel at the same coordinate position between the first sample image 70 and each first comparison image PA comparison is made. Thus, the control value 52 when the first comparison image with the smallest difference in brightness with respect to the first sample image 70 is captured is determined as the fifth control value 52e.

[0146] Furthermore, the control unit 50 of the second cutting device 2b calculates the sum N of the differences in pixel values of the pixels at the same coordinate positions of the second sample image 80 and each second comparison image. P A comparison is made. Thus, the control value 52 when the second comparison image with the smallest difference in brightness with respect to the second sample image 80 is captured is determined as the sixth control value 52f.

[0147] After the control value determination step S40, the control unit 50 of the second cutting device 2b sets the difference between the fifth control value 52e and the third control value 52c as the first correction value 58a of the control value 52 of the second cutting device 2b with respect to the coaxial epi-illumination unit 38 of the first cutting device 2a.

[0148] Furthermore, the control unit 50 of the second cutting device 2b sets the difference between the sixth control value 52f and the fourth control value 52d as the second correction value 58b of the control value 52 of the second cutting device 2b with respect to the side illumination unit 44 of the first cutting device 2a (correction value setting step S50).

[0149] The first correction value 58a and the second correction value 58b are stored in the storage device 50a of the second cutting device 2b. Thus, even when there are differences in the light amounts between the first light sources 32 and further differences in the light amounts between the second light sources 42, the difference in brightness of the illuminator 48 between the first cutting device 2a and the second cutting device 2b can be reduced.

[0150] In addition to the above, the structures, methods, etc. of the above embodiments can be appropriately modified and implemented without departing from the object of the present invention. For example, the PWM (Pulse Width Modulation) method or other known methods can be used instead of the phase control method.

[0151] In addition, in the above embodiment, halogen lamps are used as the first light source 32 and the second light source 42, but LEDs can be used instead of halogen lamps. In this case, the optical fiber 40b of the side illumination unit 44 is omitted, and a plurality of LEDs are arranged on the housing 40 such that the light emitting surfaces of the LEDs are located at the plurality of openings 40a. In addition, the brightness of the illuminator 48 can also be adjusted by adjusting the voltage applied to the LEDs.

[0152] In addition, in the above-described embodiment, the cutting device 2 has been described as an example of the processing device, but the processing device may also be a laser processing device. The laser processing device irradiates a laser beam (not shown) of an unillustrated laser irradiation unit (processing unit) on the front surface 11a side of the workpiece 11 held by the holding surface 14a on the back surface 11b side instead of the cutting unit 24.

[0153] The laser irradiation unit has a laser oscillator (not shown) for generating a pulsed laser beam having a prescribed wavelength absorbed by the workpiece 11. The laser beam emitted from the laser oscillator is irradiated onto the front surface 11a side through a prescribed optical system including a condenser lens and the like.

[0154] The camera unit 26 for photographing the workpiece 11 is provided at a position adjacent to the laser irradiation unit. An image of the front surface 11a side of the workpiece 11 held by the holding surface 14a is acquired using the camera unit 26.

Claims

1. A method for adjusting the brightness of an illuminator in a processing apparatus, characterized in that: The method for adjusting the brightness of the illuminator in the processing apparatus has the following steps: A first storage step, in a first processing apparatus among a plurality of processing apparatuses each having a camera unit, a processing unit, and a storage device, the storage device of the first processing apparatus stores a sample image obtained by photographing a specified pattern provided on a workpiece at the brightness of the illuminator specified by a first control value together with the first control value. Here, the camera unit has the illuminator whose brightness can be adjusted, an objective lens, and an imaging element, and the workpiece is photographed by causing the reflected light of the light irradiated from the illuminator to the workpiece to enter the imaging element via the objective lens. The processing unit processes the workpiece based on the image obtained by the camera unit, and the storage device stores the control value specifying the brightness of the illuminator and the processing conditions of the processing unit when processing the workpiece; A copying step, copying the sample image and the first control value stored in the storage device of the first processing apparatus together with the processing conditions used in the first processing apparatus, and storing them in the storage device of the second processing apparatus; A second storage step, in the second processing apparatus, the storage device of the second processing apparatus stores a plurality of comparison images obtained by photographing the specified pattern of the workpiece at the brightness of the illuminator specified by a plurality of different control values; A control value determination step, comparing the sample image and the plurality of comparison images, and determining the control value when the comparison image with the smallest difference in brightness and darkness with respect to the sample image is photographed as the second control value; and A correction value setting step, setting the difference between the second control value and the first control value as the correction value of the control value of the second processing apparatus with respect to the first processing apparatus in the second processing apparatus.

2. The method for adjusting the brightness of the illuminator in a processing apparatus according to claim 1, characterized in that: In the control value determination step, at each same position in the vertical and horizontal directions of the sample image and each comparison image, the difference in the value indicating the degree of brightness of each pixel constituting the image is calculated, and the sum of the differences is compared.

3. The method for adjusting the brightness of the illuminator in a processing apparatus according to claim 1 or 2, characterized in that: The illuminator has: a coaxial epi-illumination unit that irradiates light along the optical axis of the objective lens; And a side-illumination unit that irradiates light inclined with respect to the optical axis of the objective lens. In the first storage step, the first control value includes a third control value and a fourth control value, the sample image includes a first sample image and a second sample image, the first sample image is obtained by photographing the specified pattern of the workpiece by only lighting the coaxial epi-illumination unit according to the third control value, the second sample image is obtained by photographing the specified pattern of the workpiece by only lighting the side-illumination unit according to the fourth control value, and the storage device of the first processing device stores the first sample image and the second sample image together with the third control value and the fourth control value. In the second storage step, the storage device of the second processing device stores a plurality of first comparison images and a plurality of second comparison images. The plurality of first comparison images are obtained by photographing the specified pattern of the workpiece by only lighting the coaxial epi-illumination unit according to respectively different control values, and the plurality of second comparison images are obtained by photographing the specified pattern of the workpiece by only lighting the side-illumination unit according to respectively different control values. In the control value determination step, the second control value includes a fifth control value and a sixth control value. The first sample image is compared with each first comparison image, and the control value when the first comparison image with the smallest difference in brightness and darkness with respect to the first sample image is photographed is determined as the fifth control value. Also, the second sample image is compared with each second comparison image, and the control value when the second comparison image with the smallest difference in brightness and darkness with respect to the second sample image is photographed is determined as the sixth control value. In the correction value setting step, the difference between the fifth control value and the third control value is set as the first correction value of the control value of the second processing device with respect to the first processing device in the second processing device, and the difference between the sixth control value and the fourth control value is set as the second correction value of the control value of the second processing device with respect to the first processing device in the second processing device.

Images