Processing equipment

Abstract

To reprocess a workpiece without reducing processing efficiency even when an abnormality occurs during processing.SOLUTION: A processing device includes a chuck table that holds a workpiece having streets that intersect with each other on a holding surface, a processing unit that processes the workpiece held on the chuck table along the streets, and a control unit. When processing is interrupted with an unprocessed area left while causing the processing unit to process the workpiece from one end of the street to the other end, the control unit rotates the chuck table 180 degrees and causes the processing unit to process the unprocessed area of the workpiece from the other end of the street.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a processing apparatus for processing and dividing a workpiece such as a semiconductor wafer along a street.

Background Art

[0002] In the manufacturing process of device chips incorporated in electronic devices and the like, plate-shaped workpieces typified by semiconductor wafers and resin package substrates are processed by various processing apparatuses. A grid-like division planned line called a street is set on the plate-shaped workpiece, and devices such as ICs and LSIs are arranged in each region partitioned by the street. When the workpiece is divided along this street, individual device chips are manufactured.

[0003] There is known a processing apparatus having a function of detecting an abnormality in the processing being performed (see Patent Document 1). In this processing apparatus, when any abnormality is detected during the processing of the workpiece, the processing is temporarily stopped. The user of the processing apparatus or the like checks the state of the processing apparatus and the workpiece, and after making necessary adjustments to the processing apparatus, resumes the processing.

[0004] However, the processing may be easily resumed in a state where the adjustment to the temporarily stopped processing apparatus is insufficient, and an abnormality may continue to occur in the processing apparatus. Therefore, there is known a processing apparatus in which restart conditions for processing are determined depending on the content of the abnormality that occurred during processing, and a specific restart procedure is required when a specific abnormality occurs (see Patent Document 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] If an anomaly is detected and machining stops while a workpiece is being processed along a street, an unmachined area remains in that street. Then, after the machining equipment has been adjusted, when the partially machined street is re-machined, machining may start from the point where it stopped in the unmachined area. In this case, a special procedure that is time-consuming and complicated is required to resume machining from the middle of the street. Moreover, if the machining tool acts on the last abnormal machining mark formed before machining stopped, unexpected force may be applied to the tool or workpiece, potentially causing damage to the tool or other equipment.

[0007] Alternatively, if an anomaly is detected and processing stops, the reprocessing of the street in progress may be abandoned, and processing may resume from the next street. In this case, the street with unprocessed areas remains, resulting in areas that are not divided on the wafer, which reduces the number of device chips obtained. Therefore, it is conceivable that the user may operate the processing equipment to reprocess the street from a desirable position where no damage to the processing tools occurs. However, this is time-consuming and significantly reduces processing efficiency.

[0008] The present invention has been made in view of the above problems, and its objective is to provide a processing apparatus that can reprocess a workpiece when an abnormality occurs during processing, without putting a load on the processing tool and without significantly reducing the number of device chips manufactured or the processing efficiency. [Means for solving the problem]

[0009] According to one aspect of the present invention, the present invention comprises a chuck table for holding a workpiece having a plurality of intersecting streets on a holding surface, a machining unit for machining the workpiece held on the chuck table along the streets, a machining feed unit for moving the chuck table and the machining unit relative to each other along the machining feed direction in a direction parallel to the holding surface, a rotation unit for rotating the chuck table about a rotation axis in a direction perpendicular to the holding surface, and a control unit for controlling the chuck table, the machining unit, the machining feed unit, and the rotation unit, wherein the control unit moves the chuck table and the machining unit relative to each other along the machining feed direction with the machining feed unit while the machining unit is machining the workpiece from one end of the street to the other. On the street in the process of being processed If machining is interrupted while an unmachined area remains, the chuck table is rotated 180 degrees by the rotary unit, and the machining feed unit moves the chuck table and the machining unit relative to each other along the machining feed direction while the machining unit is being processed. The unprocessed area remains A processing apparatus is provided that is characterized by processing the unprocessed area of ​​the workpiece from the other end of the street.

[0010] Preferably, the processing unit is a cutting unit that cuts the workpiece with an annular cutting blade.

[0011] Alternatively, preferably, the processing unit is a laser processing unit that irradiates the workpiece with a laser beam to laser process the workpiece.

[0012] According to another aspect of the present invention, a chuck table holds a workpiece having a plurality of intersecting streets on a holding surface; a machining unit machines the workpiece held on the chuck table along the streets; a machining feed unit moves the chuck table and the machining unit relative to each other along the machining feed direction in a direction parallel to the holding surface; a rotary unit that can rotate the chuck table about a rotation axis in a direction perpendicular to the holding surface; and a control unit that controls the chuck table, the machining unit, the machining feed unit, and the rotary unit, wherein if machining is interrupted while the machining unit is machining the workpiece from one end of the street to the other while the machining feed unit is moving the chuck table and the machining unit relative to each other along the machining feed direction, leaving an unmachined area, the rotary unit rotates the chuck table 180 degrees, and the machining feed unit moves the chuck table and the machining unit relative to each other along the machining feed direction while the machining unit is machining the unmachined area of ​​the workpiece from the other end of the street. The control unit has an abnormality detection unit that detects abnormalities that occur while the workpiece is being processed by the processing unit, and interrupts the processing of the workpiece by the processing unit when the abnormality detection unit detects such abnormality. A processing apparatus characterized by the above is provided.

[0013] More preferably, the abnormality detection unit further comprises an imaging unit that images the workpiece held by the chuck table, the imaging unit causes the imaging unit to image the position of the workpiece processed by the processing unit, and detects the abnormality based on the image acquired by the imaging unit. [Effects of the Invention]

[0014] In a processing apparatus according to one aspect of the present invention, if processing is interrupted while the processing unit is working on a workpiece, the control unit rotates the chuck table 180 degrees, allowing the processing unit to process the unprocessed area from the opposite direction. As a result, the unprocessed area is never left unattended, and the device chip is manufactured with the minimum necessary loss.

[0015] Furthermore, in the street being reworked, processing is not resumed from the point where processing was interrupted, but rather from the other end of the street where there are no abnormalities. In this case, since the processing tool is not applied to the point where processing was interrupted and there are abnormalities when starting rework, damage to the processing tool, etc., can be prevented. In addition, since the user of the processing equipment does not need to input special instructions such as the starting position of rework into the processing equipment and operate the equipment, and since there is no need for a careful procedure to start reworking from the middle of the street, processing efficiency is improved.

[0016] Therefore, the present invention provides a processing apparatus that, when an abnormality occurs during processing of a workpiece, can reprocess the workpiece without putting a load on the processing tool and without significantly reducing the number of device chips manufactured or the processing efficiency. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic perspective view showing an example of a processing apparatus. [Figure 2] This is a schematic perspective view of the workpiece. [Figure 3] This is a schematic side view showing the chuck table, machining unit, and machining feed unit. [Figure 4]It is a perspective view schematically showing a processing unit for processing a workpiece. [Figure 5] FIG. 5(A) is a plan view schematically showing the surface side of the workpiece, and FIG. 5(B) is a plan view schematically showing the surface side of the workpiece with the processing interrupted halfway. [Figure 6] FIG. 6(A) is a plan view schematically showing the front side of the workpiece whose processing has been interrupted once and then resumed, and FIG. 6(B) is a plan view schematically showing the front side of the workpiece whose unprocessed area is processed from the reverse side. [Figure 7] FIG. 7(A) is a flowchart showing the flow of each step of the processing method of the workpiece along one street, and FIG. 7(B) is a flowchart showing the flow of each step of the processing method of the workpiece in which reprocessing is performed after the end of a predetermined processing when an abnormality is detected during the processing of the workpiece.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The processing apparatus according to this embodiment processes a plate-shaped workpiece such as a semiconductor wafer. FIG. 1 is a perspective view schematically showing a processing apparatus 2 and a frame unit 11 including a workpiece 1, and FIG. 2 is a perspective view schematically showing the frame unit 11.

[0019] First, the workpiece 1 processed by the processing apparatus 2 will be described. The workpiece 1 is, for example, a substantially disc-shaped wafer formed of Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor materials.

[0020] Alternatively, the workpiece 1 may be a plate-shaped substrate or the like made of materials such as sapphire, quartz, glass, ceramics, etc. The glass is, for example, alkali glass, non-alkali glass, soda lime glass, lead glass, borosilicate glass, fused silica, etc. Further, the workpiece 1 may be a package substrate in which a plurality of chips are sealed with resin. However, the workpiece 1 is not limited to this.

[0021] Figure 2 includes a schematic perspective view of a disc-shaped semiconductor wafer, which is an example of a workpiece 1. For example, multiple devices 5, such as ICs and LSIs, are formed on the surface 1a of the workpiece 1. Dividing lines called streets 3 are set between the devices 5 on the workpiece 1. Then, as shown in Figure 4, the workpiece 1 is cut along the streets 3 to form processing marks (dividing grooves) 13, thereby dividing the workpiece 1 and forming individual device chips.

[0022] The workpiece 1 can be cut using a cutting device equipped with an annular cutting blade. The processing device 2 according to this embodiment is, for example, a cutting device for cutting the workpiece 1. However, the workpiece 1 may be processed by a processing device 2 other than a cutting device. For example, the processing device 2 may be a laser processing device that can laser process the workpiece 1 by irradiating a laser beam along the street 3. The embodiment will be described below using the case where the processing device 2 is a cutting device as an example, but the processing device 2 is not limited to this.

[0023] Before the workpiece 1 is loaded into the processing apparatus 2, the workpiece 1 is integrated with the dicing tape 9 and the ring frame 7 to form a frame unit 11. Figure 2 is a schematic perspective view showing the workpiece 1 included in the frame unit 11. The dicing tape 9 is attached to the ring frame 7 so as to close the opening of the ring frame 7, which is made of a metal such as aluminum. Then, the back surface 1b of the workpiece 1 is attached to the dicing tape 9 that is exposed in the opening of the ring frame 7.

[0024] The dicing tape 9 is, for example, an adhesive tape comprising a base layer and an adhesive layer supported by the base layer. However, the dicing tape 9 is not limited to this and may not have an adhesive layer. For example, the dicing tape 9 may be a sheet made of a polyolefin material or a sheet made of a polyester material. In this case, the frame unit 11 can be formed by integrating the sheet with the workpiece 1 and the ring frame 7 by a method such as heat pressing.

[0025] Once the frame unit 11 is formed, the workpiece 1 can be handled via the ring frame 7 and the dicing tape 9, making the handling of the workpiece 1 easier. Furthermore, since the device chips formed by dividing the workpiece 1 are fixed directly to the dicing tape 9, the handling of the device chips is also easier. After dividing the workpiece 1, when the dicing tape 9 is expanded radially outward inside the opening of the ring frame 7, gaps are created between the individual device chips, making it easy to pick up the device chips.

[0026] Next, the processing apparatus 2 for processing the workpiece 1 will be described. Figure 1 is a schematic perspective view showing a cutting apparatus, which is an example of the processing apparatus 2 according to this embodiment. The processing apparatus 2 is equipped with a base 4 that supports each component. A rectangular opening 4a, which is long in the X-axis direction (processing feed direction), is formed on the upper surface of the base 4.

[0027] Figure 3 is a schematic side view showing the internal structure of the opening 4a. Inside the opening 4a are an X-axis moving table 6a and a machining feed unit 6 that moves the X-axis moving table 6a in the machining feed direction (X-axis direction). A chuck table 10 is mounted on the X-axis moving table 6a.

[0028] The machining feed unit 6 has a pair of X-axis guide rails 6c provided at the bottom of the opening 4a along the X-axis direction. An X-axis moving table 6a is slidably mounted on the X-axis guide rails 6c. A nut portion (not shown) is provided at the bottom of the X-axis moving table 6a, and an X-axis ball screw 6b parallel to the X-axis guide rails 6c is screwed into this nut portion. An X-axis pulse motor 6d is connected to one end of the X-axis ball screw 6b.

[0029] When the X-axis pulse motor 6d rotates the X-axis ball screw 6b, the X-axis moving table 6a slides relative to the X-axis guide rail 6c and moves in the machining feed direction (X-axis direction). When the machining feed unit 6 is activated and the X-axis moving table 6a is moved, the chuck table 10 placed on the X-axis moving table 6a is machine-feeded. The machining feed unit 6 consists of the X-axis moving table 6a, X-axis ball screw 6b, X-axis guide rail 6c, X-axis pulse motor 6d, etc., and has the function of machine-feeding the chuck table 10.

[0030] The machining feed unit 6 may move the machining unit 14 (described later) along the machining feed direction instead of the chuck table 10, or it may move both the chuck table 10 and the machining unit 14. In other words, the machining feed unit 6 has the function of moving the chuck table 10 and the machining unit 14 relatively along the machining feed direction.

[0031] As shown in Figure 1, a dustproof and waterproof cover 8 is provided at the upper end of the opening 4a to cover the machining feed unit 6. The dustproof and waterproof cover 8 continues to cover the machining feed unit 6 as the chuck table 10 moves, with the front and rear portions of the chuck table 10 expanding and contracting accordingly.

[0032] A chuck table 10 is mounted on the X-axis moving table 6a. A porous member 10c (see Figure 3) is embedded in the upper surface of the chuck table 10, and the upper surface of the porous member 10c serves as a holding surface 10a. Inside the chuck table 10, a suction passage is formed, with one end connected to the porous member 10c and the other end connected to a suction source, which is composed of a pump or the like (not shown). Clamps 10b for gripping the ring frame 7 of the frame unit 11 are provided around the chuck table 10.

[0033] A projection 12 is provided at the front corner of the base 4 of the processing device 2, extending laterally from the base 4. A space is formed inside the projection 12, and a cassette elevator 46 is installed in this space. A cassette 48 capable of accommodating multiple frame units 11 is placed on the upper surface of the cassette elevator 46. The frame units 11, including the workpiece 1, are placed in the cassette 48 and transported into the processing device 2. The cassette elevator 46 raises and lowers the cassette 48.

[0034] A transport unit (not shown) is provided near the opening 4a to transport the frame unit 11 from the cassette 48 to the chuck table 10. The frame unit 11, pulled out from the cassette 48 by the transport unit, is placed on the holding surface 10a of the chuck table 10.

[0035] Then, the ring frame 7 is gripped by the clamp 10b, and the negative pressure generated by the suction source is applied to the workpiece 1 via the suction passage and porous member 10c through the dicing tape 9, causing the workpiece 1 to be held by the chuck table 10. The chuck table 10 is connected to and supported by a rotary unit 10e having a rotational drive source such as a motor, and rotates around a rotation axis 10f aligned perpendicular to the holding surface 10a.

[0036] On the upper surface of the base 4, a support structure 16 for supporting the processing unit 14 that processes the workpiece 1 is positioned so as to protrude above the opening 4a. On the upper front of the support structure 16, there is an indexing feed unit 18a for moving the processing unit 14 along the indexing feed direction (Y-axis direction) and a lifting unit 18b for raising and lowering the processing unit 14.

[0037] The indexing feed unit 18a is positioned on the front of the support structure 16 and includes a pair of Y-axis guide rails 20 that are parallel to the Y-axis direction. A Y-axis moving plate 22 is slidably mounted on the Y-axis guide rails 20. A nut portion (not shown) is provided on the back side (rear side) of the Y-axis moving plate 22, and a Y-axis ball screw 24 parallel to the Y-axis guide rails 20 is screwed into this nut portion.

[0038] A Y-axis pulse motor (not shown) is connected to one end of the Y-axis ball screw 24. When the Y-axis ball screw 24 is rotated by the Y-axis pulse motor, the Y-axis moving plate 22 moves in the Y-axis direction along the Y-axis guide rail 20.

[0039] A lifting unit 18b is provided on the surface (front) of the Y-axis moving plate 22. The lifting unit 18b comprises a pair of Z-axis guide rails 26 that are fixed to the surface of the Y-axis moving plate 22 and are parallel to the Z-axis direction. The Z-axis moving plate 28 is slidably mounted on the Z-axis guide rails 26.

[0040] A nut (not shown) is provided on the back (rear) side of the Z-axis moving plate 28, and a Z-axis ball screw 30 parallel to the Z-axis guide rail 26 is screwed into this nut. A Z-axis pulse motor 32 is connected to one end of the Z-axis ball screw 30. When the Z-axis ball screw 30 is rotated by the Z-axis pulse motor 32, the Z-axis moving plate 28 moves in the Z-axis direction along the Z-axis guide rail 26.

[0041] A machining unit 14 for machining the workpiece 1 held by the chuck table 10 and an imaging unit (camera unit) 34 for imaging the upper surface of the workpiece 1 held by the chuck table 10 are fixed to the lower part of the Z-axis moving plate 28. When the Y-axis moving plate 22 is moved in the Y-axis direction by the indexing feed unit 18a, the machining unit 14 and the imaging unit 34 are indexed and fed. Also, when the Z-axis moving plate 28 is moved in the Z-axis direction by the lifting unit 18b, the machining unit 14 and the imaging unit 34 are raised and lowered.

[0042] Figure 3 includes a schematic side view showing a part of the machining unit 14. Figure 4 also includes a schematic perspective view showing the machining unit 14. The machining unit 14 is a cutting unit that, for example, is equipped with an annular cutting blade (machining tool) 40 and cuts the workpiece 1 with the cutting blade 40.

[0043] The machining unit (cutting unit) 14 includes a spindle housing 36 that rotatably houses the base end of a spindle (not shown) which forms a rotation axis parallel to the Y-axis direction. Inside the spindle housing 36 is a rotation drive source such as a motor that rotates the spindle, and when this rotation drive source is activated the spindle rotates. An annular cutting blade 40 is fixed to the tip of the spindle. When the spindle rotates, the cutting blade 40 can also be rotated.

[0044] The cutting blade 40 comprises a binder formed in an annular shape from a metal or resin material, and a grinding wheel portion containing abrasive grains made of diamond or the like, dispersed and fixed within the binder. When the Z-axis moving plate 28 is moved to lower the cutting blade 40 to a predetermined height, and the machining feed unit 6 is activated to feed the chuck table 10, the grinding wheel portion of the rotating cutting blade 40 comes into contact with the workpiece 1, and the workpiece 1 is cut.

[0045] As shown in Figure 4, the machining unit 14 further comprises a blade cover 38 that covers the cutting blade 40, and a cutting fluid supply nozzle 42 connected to the blade cover 38. When the workpiece 1 is cut by the cutting blade 40, cutting chips and machining heat are generated from the grinding wheel and the workpiece 1. Therefore, while the workpiece 1 is being cut by the cutting blade 40, cutting fluid, consisting of pure water or the like, is sprayed from the cutting fluid supply nozzle 42 onto the cutting blade 40 and the workpiece 1. The cutting fluid removes cutting chips and machining heat.

[0046] However, the processing unit 14 is not limited to this. The processing unit 14 may be a laser processing unit that laser processes the workpiece 1 with a laser beam. In that case, the processing unit 14 has a laser oscillator and a processing head, and the laser beam emitted by the laser oscillator is irradiated from the processing head onto the workpiece 1 held by the chuck table 10. Laser processing is performed by positioning the focal point of the laser beam at a predetermined height and operating the processing feed unit 6 to feed the workpiece 1 while irradiating the focal point with the laser beam.

[0047] The imaging unit (camera unit) 34 captures images of the surface 1a of the workpiece 1 held by the chuck table 10. The imaging unit 34 is equipped with an image sensor such as a CCD camera or a CMOS sensor and has the function of transmitting the captured images to the control unit 50, which will be described later. The captured images obtained by the imaging unit 34 are used when positioning the processing unit 14 to process a predetermined area. In addition, by acquiring images showing the processed area of ​​the workpiece 1, the quality of the processing result can be evaluated.

[0048] A cleaning unit 44 for cleaning the workpiece 1 after processing is provided behind the opening 4a of the base 4. The workpiece 1 after processing is transported from the chuck table 10 to the cleaning unit 44 by a transport mechanism (not shown).

[0049] The cleaning unit 44 is equipped with a spinner table that holds the workpiece 1 by suction within a cylindrical cleaning space. Above the spinner table, a spray nozzle is positioned to spray a cleaning fluid (typically a two-fluid mixture of water and air) towards the workpiece 1. By rotating the spinner table holding the workpiece 1 and spraying the cleaning fluid from the spray nozzle, the workpiece 1 can be cleaned. The workpiece 1 cleaned by the cleaning unit 44 is then stored in a cassette 48, for example, by a transport mechanism (not shown).

[0050] The processing apparatus 2 further includes a control unit 50 that controls each component, including a chuck table 10, a processing unit 14, a processing feed unit 6, a rotation unit 10e, an imaging unit 34, an indexing feed unit 18a, and a lifting unit 18b.

[0051] The control unit 50 is composed of a computer that includes, for example, a processing unit such as a CPU (Central Processing Unit), a main memory such as DRAM (Dynamic Random Access Memory), and an auxiliary storage device such as flash memory. The functions of the control unit 50 are realized by operating the processing unit and other devices according to the software stored in the auxiliary storage device.

[0052] The control unit 50 has pre-programmed and registered processing conditions for processing the workpiece 1. The control unit 50 then controls each component according to the processing conditions. The processing conditions are set appropriately according to the type of workpiece 1 and the desired processing result. The control unit 50 then controls each component while referring to the information sent from each component to proceed with the processing of the workpiece 1 in a predetermined procedure.

[0053] In other words, the control unit 50 includes a storage unit 50a that can register various information, including various processing conditions, and a processing control unit 50b that controls each component according to the processing conditions registered in the storage unit 50a to perform processing on the workpiece 1.

[0054] Furthermore, the processing device 2 may be equipped with a touch panel display (not shown) used for inputting commands to the control unit 50 and displaying various information. The processing device 2 may also be equipped with an alarm unit (not shown) that emits an alarm to the user via a lamp or alarm sound. In addition, the processing device 2 may be equipped with a monitoring unit such as an ammeter for measuring the load current value of the rotation drive source of the spindle connected to the cutting blade 40, and a pressure meter for measuring the pressure of the negative pressure generated by a suction source such as a pump connected to the chuck table 10.

[0055] In the processing apparatus 2, the frame units 11 housed in the cassette 48 are sequentially transported to the chuck table 10 and held in place by suction on the chuck table 10. Then, the workpiece 1 is processed on the chuck table 10 by the processing unit 14 under predetermined processing conditions. After the processed workpiece 1 is washed by the washing unit 44, it is placed back into the cassette 48. After processing of all the workpieces 1 of the frame units 11 housed in the cassette 48 and brought into the processing apparatus 2 is completed, the cassette 48 is removed from the processing apparatus 2.

[0056] In the processing device 2, a malfunction may occasionally occur in one of its components during the processing of the workpiece 1, preventing the processing from proceeding as planned. In this case, continuing the processing would not only fail to yield the desired processing results, but could also lead to damage to the workpiece 1 or the cutting blade (processing tool) 40.

[0057] Therefore, the processing device 2 should be equipped with a function to detect abnormalities in the processing being performed. If any abnormality is detected while processing the workpiece 1, it should temporarily suspend processing and issue an alarm to the user of the processing device 2. If the processing device 2 stops due to an abnormality, the user should check the status of the processing device 2 and the workpiece 1, make any necessary adjustments to the processing device 2, and then have the processing device 2 resume processing.

[0058] Here, if an abnormality is detected and machining stops while the workpiece 1 is being machined along street 3, an unmachined area remains on street 3 during machining. This will be explained in more detail. Figure 5(A) is a schematic plan view showing the surface 1a of the unmachined workpiece 1, and Figure 5(B) is a schematic plan view showing the workpiece 1 when machining stops due to an abnormality detected while machining is being performed by the machining device 2.

[0059] When the workpiece 1 is machined (cut) by the machining unit (cutting unit) 14, machining marks (cutting grooves) 13 are successively formed on each street 3. Then, as shown in Figure 5(B), if an abnormality is detected and machining is stopped while machining is being performed from one end 3a to the other end 3b of a street 3, an unmachined area 3c remains from position 15 to the other end 3b of street 3.

[0060] Subsequently, when the processing device 2 is adjusted and processing of the workpiece 1 is resumed, if processing of the unprocessed area 3c is resumed from position 15, an unexpected force may act on the cutting blade (working tool) 40 or the workpiece 1, causing damage. One of the reasons for this is that an abnormality occurs in the processing mark 13 formed near position 15 just before processing is stopped by the processing device 2.

[0061] For example, if the negative pressure applied by the chuck table 10 to the workpiece 1 when machining position 15 is weak, the workpiece 1 may not be held in place by sufficient force, causing it to lift or vibrate. Also, if the amount of cutting fluid supplied to the cutting blade 40 etc. when machining position 15 is insufficient, the cutting blade 40 etc. may not be sufficiently cooled, causing the grinding wheel portion of the cutting blade 40 to expand due to heat. In such cases, abnormal machining marks 13 may be formed at position 15 of the workpiece 1.

[0062] Furthermore, if there is an abnormal fluctuation in the drive current of the rotational drive source that rotates the spindle to which the cutting blade 40 is connected, damage or deformation of the cutting blade 40, or meandering or misalignment of the machining marks 13 may occur. If machining is resumed at the position 15 where such an abnormality has occurred, unexpected forces will be applied to the cutting blade 40 and other components.

[0063] Furthermore, when machining is stopped, the lifting unit 18b is activated to raise and retract the cutting blade 40 from the workpiece 1. Therefore, when resuming machining, the cutting blade 40 is lowered near position 15 and carefully and precisely cuts into the workpiece 1 from above. However, when the cutting blade 40 cuts into the workpiece 1 from above, chipping, known as chipping, is likely to occur at the outer edge of the machining mark 13, which can reduce the quality of the formed machining mark 13 and may even cause the formed chip to break.

[0064] Therefore, when an abnormality is detected and machining stops, the unmachined area 3c of the street 3 being machined is not remachined, and machining may be resumed from the next street 3. In this case, since the street 3 that was being machined when machining stopped is left untouched, an area of ​​the workpiece 1 remains undivided, resulting in a problem where the number of chips obtained decreases. It is conceivable that the user could operate the machining device 2 to resume machining of the workpiece 1 normally from near the area where machining stopped, but this would be time-consuming and would significantly reduce machining efficiency.

[0065] Therefore, in the processing apparatus 2 according to this embodiment, if processing stops due to an abnormality, the workpiece 1 is reprocessed without putting a load on the cutting blade (processing tool) 40, etc., and without significantly reducing the number of device chips manufactured or the processing efficiency. The following description of the processing apparatus 2 according to this embodiment will focus on the configuration in which processing is stopped when an abnormality is detected during processing and the workpiece 1 is then reprocessed.

[0066] First, we will describe a configuration that monitors for abnormalities during machining and stops machining when an abnormality is detected. In the machining apparatus 2, the operating status of each component is monitored by an ammeter that measures the load current value of the rotational drive source of the spindle connected to the cutting blade 40, a pressure gauge that measures the pressure value of the negative pressure acting on the chuck table 10, and a flow meter that measures the flow rate of the cutting fluid. Alternatively, in the machining apparatus 2, the workpiece 1 after machining is photographed by the imaging unit 34, and the machining results are evaluated from the captured image.

[0067] For example, the control unit 50 of the processing apparatus 2 has an abnormality detection unit 50c that detects abnormalities that occur while the workpiece 1 is being processed by the processing unit 14. The abnormality detection unit 50c detects the occurrence of an abnormality when the load current value of the spindle rotation drive source, the pressure value of the negative pressure acting on the chuck table 10, or the flow rate of the cutting fluid fluctuates in a manner different from the normal. Alternatively, the abnormality detection unit 50c causes the imaging unit 34 to image the position of the workpiece 1 processed by the processing unit 14, and detects an abnormality based on the image acquired by the imaging unit 34.

[0068] The machining control unit 50b of the control unit 50 interrupts the machining of the workpiece 1 by the machining unit 14 when an abnormality is detected by the abnormality detection unit 50c. For example, it stops the machining feed unit 6 to interrupt the machining feed of the chuck table 10, etc., and activates the lifting unit 18b to raise the cutting blade 40.

[0069] Alternatively, for example, the control unit 50 may cause the imaging unit 34 to successively capture images of the processing marks 13 formed on the workpiece 1 by the processing, and display the obtained images successively on a touch panel display. The user of the processing device 2 may monitor for any abnormalities by visually inspecting the processing marks 13 shown in the successively displayed images. When the user detects an abnormality, they can input a command to stop processing to the processing device 2, thereby stopping the processing. In other words, detection of abnormalities does not necessarily have to be performed by the functions of the control unit 50.

[0070] In this way, the machining feed unit 6 moves the chuck table 10 and the machining unit 14 relative to each other along the machining feed direction, and while the machining unit 14 is machining the workpiece 1 from one end 3a to the other end 3b of the street 3, the machining is interrupted, leaving an unmachined area 3c. In this case, the control unit 50 acquires information about the street 3 where the unmachined area 3c of the workpiece 1 remains, and the position 15 where the machining stopped, and stores this information in the storage unit 50a.

[0071] The control unit 50 then rotates the chuck table 10 by 180 degrees using the rotary unit 10e before resuming the interrupted machining. Alternatively, machining is resumed from the next scheduled street 3 after the street 3 where machining was interrupted, and the chuck table 10 is rotated by 180 degrees using the rotary unit 10e after the machining has progressed to a predetermined stage.

[0072] Subsequently, the control unit 50 moves the chuck table 10 and the machining unit 14 relative to each other along the machining feed direction using the machining feed unit 6, while causing the machining unit 14 to machine the unmachined area 3c of the workpiece 1 from the other end 3b of the street 3. In other words, the remaining unmachined area 3c of the street 3 is machined from the opposite direction.

[0073] Figure 6(A) is a schematic plan view of the workpiece 1 after machining has been interrupted, leaving one street 3 with an unmachined area 3c, while machining has been performed along all other parallel streets 3. Figure 6(B) is a schematic plan view of the workpiece 1 after the chuck table 10 has been rotated 180 degrees by the rotary unit 10e, and the remaining street 3 with the unmachined area 3c has been remachined from the opposite direction, forming machining marks 17. In Figure 6(B), for ease of explanation, the machining marks 17 formed by the remachining are shown as dashed lines.

[0074] The control unit 50 reads information about the street 3, including the unprocessed area 3c, and information about the position 15, stored in the memory unit 50a, and determines the position where reprocessing will be performed. Then, the reprocessing is started from the other end 3b of the street 3. This reprocessing is carried out in the same way as normal processing performed from one end 3a of the street 3.

[0075] Therefore, unlike when rework is started from a position 15 where an abnormal machining mark 13 is formed nearby, no unexpected force is applied to the cutting blade (working tool) 40 or the workpiece 1. Also, unlike when rework is performed by cutting into the workpiece 1 from above with the cutting blade 40, no abnormal chipping is formed on the outer edge of the machining mark 17.

[0076] When reprocessing is performed in this manner, no unprocessed area 3c remains in the workpiece 1, allowing the maximum number of device chips to be manufactured from the workpiece 1. However, it is possible that normal processing is not performed near position 15, resulting in the absence of normal processing marks 13, and that high-quality device chips may not be obtained from this vicinity. Therefore, it is preferable that device chips formed from the workpiece 1 near position 15 be subjected to a special inspection process or distinguished from other device chips formed in that area.

[0077] Furthermore, rework from the other end 3b of street 3 may be terminated just before position 15, which is the end point of the unworked area 3c. In this case, the cutting blade (machining mark) 40 does not machine position 15 where abnormal machining marks 13 may be formed, thus preventing damage to the cutting blade 40, etc., caused by machining being performed near the abnormal machining marks 13. However, the machining apparatus 2 according to this embodiment is not limited to this, and rework may proceed up to position 15.

[0078] When the cutting blade 40 of the processing unit 14 has advanced to position 15 or its vicinity, the lifting unit 18b is activated to raise the cutting blade 40, thereby ending the rework. After all predetermined processing, including rework, has been performed on the workpiece 1, the frame unit 11 containing the workpiece 1 is removed from the chuck table 10.

[0079] Thus, in the processing apparatus 2 according to this embodiment, even if an abnormality is detected during processing of the workpiece 1 and processing is interrupted, the street 3 including the unprocessed area 3c can be reprocessed without damaging the cutting blade 40 or the like. Furthermore, when the control unit 50 stores information regarding the street 3 that needs to be reprocessed and the position 15 where processing stopped in the storage unit 50a, reprocessing can be carried out easily and quickly without the user of the processing apparatus 2 having to give detailed instructions about reprocessing.

[0080] Preferably, the frequency of abnormalities occurring while processing the workpiece 1 in the processing device 2 is low, and in reality, the frequency of abnormalities is low, so the number of workpieces 1 that undergo reprocessing in the processing device 2 according to this embodiment is limited. However, in the processing device 2 according to this embodiment, reprocessing of workpieces 1 that require reprocessing is carried out efficiently and stably, so that other workpieces 1 processed afterward can also be processed quickly.

[0081] Therefore, the processing apparatus 2 according to this embodiment is beneficial not only for processing workpieces 1 that require reprocessing, but also for processing workpieces 1 that ultimately do not require reprocessing. Furthermore, even if no abnormalities are detected while multiple workpieces 1 are being processed by the processing apparatus 2, and as a result all workpieces 1 are processed without interruption, the processing apparatus 2 is still beneficial simply because it has the function to efficiently perform reprocessing. For example, when operating the processing apparatus 2, there is no need to prepare for inefficient reprocessing.

[0082] Next, the processing method for the workpiece 1 performed by the processing apparatus 2 according to this embodiment will be described. The following description explains the structure and function of the processing apparatus 2 according to this embodiment from the perspective of the processing method. Figure 7(A) is a flowchart showing the flow of each step in the processing method for processing the workpiece 1 along one street 3, and Figure 7(B) is a flowchart showing the flow of each step in the processing method for reprocessing the workpiece 1.

[0083] In the processing apparatus 2, the processing method for the workpiece 1 described in Figure 7(A) is repeatedly performed, and processing is carried out along all streets 3. Then, after the workpiece 1 has been processed along some of the streets 3, or after the workpiece 1 has been processed along all of the streets 3, the processing method for reprocessing the workpiece 1 described in Figure 7(B) is performed as needed.

[0084] First, the frame unit 11 is transported to the chuck table 10 of the processing device 2, and the workpiece 1 is held in place by suction via the dicing tape 9 on the chuck table 10. Figure 3 schematically shows a cross-sectional view of the workpiece 1 held in place by suction on the chuck table 10. Next, the imaging unit 34 images the top surface of the workpiece 1 to detect the extension direction of the street 3, and the chuck table 10 is rotated by the rotation unit 10e to align the orientation of the street 3 with the processing feed direction (X-axis direction).

[0085] Then, the machining method shown in the flow diagram in Figure 7(A) is performed on the first street 3 to be machined. First, the cutting blade 40 is positioned above the extension of the first street 3 to be machined, and the rotation of the cutting blade 40 is started, causing the cutting blade 40 to descend to a predetermined height.

[0086] Then, the machining feed unit 6 is activated to move the chuck table 10 and the machining unit 14 relative to each other. As a result, the grinding wheel portion of the cutting blade 40 comes into contact with the workpiece 1 and machining of the workpiece 1 begins (S10). At this time, cutting fluid is supplied to the cutting blade 40 and the like from the cutting fluid supply nozzle 42.

[0087] While the workpiece 1 is being processed, the abnormality detection unit 50c or the user of the processing device 2 monitors the processing device 2. If the abnormality detection unit 50c detects an abnormality (S20), the control unit 50 interrupts the processing by the processing unit 14 (S50). Alternatively, if the user of the processing device 2 or someone else detects any abnormality (S20), the user or person else inputs a command to the control unit 50 to interrupt the processing by the processing unit 14, thereby interrupting the processing (S50).

[0088] Then, if an abnormality is detected and processing is interrupted by the processing device 2, the location where the abnormality occurred is recorded (S60). That is, the storage unit 50a of the control unit 50 stores information such as the location 15 where an abnormality in the workpiece 1 was detected and processing was stopped, and the street 3 where the unprocessed area 3c remains.

[0089] Furthermore, if no abnormality is detected while machining the workpiece 1 along the street 3 (S20), or if machining has not progressed to the end of the street 3 (S30), machining continues as is (S40). Unless an abnormality is detected, machining continues to the end of the street 3. After that, when the cutting blade 40 has machined the end of the street 3, machining of that street 3 is completed (S70).

[0090] After machining of the workpiece 1 along one street 3 is completed, the workpiece 1 is indexed and fed, and the workpiece 1 is cut in the same manner along the next street 3. That is, the machining method shown in Figure 7(A) is newly implemented. Then, after machining of all streets 3 along one direction is completed, the rotary unit 10e is activated to align the orientation of the streets 3 along the other direction with the machining feed direction. Then, machining of the workpiece 1 is continued in the same manner until machining of all streets 3 is completed.

[0091] Once the workpiece 1 is successfully machined along all streets 3, it is divided into individual device chips. If machining does not proceed normally in some streets 3, an anomaly is detected and the machining is interrupted, leaving unmachined areas 3c, then remachining is performed.

[0092] Figure 7(B) shows a flow chart of a workpiece processing method in which all streets 3 are processed and then reprocessed as needed. For example, after each step is performed for all streets 3 according to the flow chart shown in Figure 7(A) and processing is completed (S80), if there is a street 3 where an abnormality is detected during processing and processing is interrupted (S90), preparations are made for reprocessing of that street 3 where an unprocessed area 3c remains.

[0093] In this case, first the rotary unit 10e is activated to rotate the chuck table 10 so that the orientation of the street 3 to be reworked is aligned with the machining feed direction (X-axis direction). At this time, the chuck table 10 is rotated 180 degrees by the rotary unit 10e from the position in which the street 3 was first machined, so that the machining proceeds from the opposite direction to when the street 3 was first machined.

[0094] Furthermore, the chuck table 10 does not need to rotate 180 degrees at once. In other words, it is sufficient for the chuck table 10 to rotate 180 degrees from the state in which Street 3, the object to be reworked, was initially processed.

[0095] More specifically, if an abnormality is detected while machining is being performed on street 3 and machining is interrupted, then machining is performed on another street 3 parallel to street 3, and then re-machining is performed, the chuck table 10 is rotated 180 degrees. Alternatively, if an abnormality is detected while machining is being performed on street 3 and machining is interrupted, re-machining may be performed immediately. In this case as well, the chuck table 10 is rotated 180 degrees.

[0096] On the other hand, if an anomaly is detected while machining is being performed on the street 3 in question and machining is interrupted, and then machining is performed on another street 3 that is not parallel to the street 3 in question, the chuck table 10 will have already rotated at this point. If remachining is then performed, the chuck table 10 is rotated so that the street 3 to be remachined is machined from the opposite direction. As a result, the chuck table 10 will be rotated 180 degrees from the state in which the street 3 was first machined.

[0097] Thus, rotating the chuck table 10 by 180 degrees means orienting the street 3, which is to be reworked, in the opposite direction to how it is during normal machining. After rotating the chuck table 10 in this way (S100), the rework (S110) is then performed.

[0098] When rework is performed, the machining control unit 50b reads information from the memory unit 50a regarding the position 15 where machining was stopped and the remaining unmachined area 3c on the street 3. Then, during rework, the unmachined area 3c is machined from the other end 3b of the street 3 (see Figure 6(B), etc.). That is, the cutting blade 40 is positioned outside the other end 3b of the street 3, the cutting blade 40 is rotated, and the machining unit 14 is lowered to a predetermined height position.

[0099] Subsequently, the machining feed unit 6 is activated to relatively feed the chuck table 10 and the machining unit 14. This causes the cutting blade 40 to cut into the unmachined area 3c of the street 3 from the other end 3b. As a result, a machining mark 17 is formed. The remachining is carried out until a machining mark 17 is formed near or at position 15.

[0100] Furthermore, if no abnormalities are detected and the machining is not interrupted while the workpiece 1 is being machined along all streets 3 (S90), there is no need to perform remachining. After the remachining of the workpiece 1 (S110) is completed, or after it is confirmed that there is no need for remachining, the frame unit 11 is removed from the chuck table 10.

[0101] After the workpiece 1 is divided into individual device chips by processing, the individual device chips are picked up from the dicing tape 9 and mounted on a predetermined mounting target. In the processing apparatus 2 according to this embodiment, even if some abnormality occurs during the processing of the workpiece 1, as many device chips as possible can be efficiently produced.

[0102] It should be noted that the present invention is not limited to the embodiments described above and can be implemented with various modifications. For example, in the above embodiments, a case was described in which a plurality of streets 3 set on the surface 1a of the workpiece 1 are processed sequentially from the edge of the workpiece 1, as shown in Figure 5(B), etc., but the processing apparatus 2 according to one aspect of the present invention is not limited to this. That is, there is no particular limit to the order in which each street 3 is processed.

[0103] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of symbols]

[0104] 1 Workpiece 1a surface 1b back side 3rd Street 3a one end 3b Other end 3c raw area 5 devices 7 Ring Frame 9 Dicing Tape 11 Frame Unit 13,17 Machining marks 15 positions 2 Processing equipment 4 base 4a aperture 6. Machining feed unit 6a Mobile Table 6b,24,30 ball screw 6c, 20, 26 Guide Rails 6d,32 pulse motor 8. Dustproof and splashproof cover 10 Chuck Table 10a Holding surface 10b Clamp 10c Porous material 10e Rotating Unit 10f Rotation axis 12 Protrusion 14 Processing Units 16 Support structure 18a Indexing feed unit 18b Lifting Unit 22,28 Mobile Plate 34 Imaging Units 36 Spindle Housing 38 Blade Cover 40 cutting blades 42 Cutting fluid supply nozzle 44 Washing Unit 46 Cassette Elevator 48 cassettes 50 control units 50a storage section 50b Machining Control Unit 50c Anomaly detection unit

Claims

1. A chuck table that holds a workpiece on a holding surface, having multiple streets that intersect with each other, A processing unit that processes the workpiece held on the chuck table along the street, A machining feed unit that moves the chuck table and the machining unit relative to each other along the machining feed direction in a direction parallel to the holding surface, A rotating unit that can rotate the chuck table about a rotation axis aligned perpendicular to the holding surface, The system comprises a chuck table, a machining unit, a machining feed unit, a rotation unit, and a control unit for controlling these units. The control unit is a machining apparatus characterized in that, while the machining feed unit moves the chuck table and the machining unit relative to each other along the machining feed direction and the machining unit is machining the workpiece from one end of the street to the other, if machining is interrupted while an unmachined area remains in the street during machining, the rotation unit rotates the chuck table 180 degrees and moves the chuck table and the machining unit relative to each other along the machining feed direction and the machining unit is machining the unmachined area of ​​the workpiece from the other end of the street where the unmachined area remains.

2. The processing apparatus according to claim 1, characterized in that the processing unit is a cutting unit that cuts the workpiece with an annular cutting blade.

3. The processing apparatus according to claim 1, characterized in that the processing unit is a laser processing unit that irradiates the workpiece with a laser beam to perform laser processing on the workpiece.

4. A chuck table for holding a workpiece on a holding surface, having a plurality of streets that intersect each other, A processing unit that processes the workpiece held on the chuck table along the street, A machining feed unit that moves the chuck table and the machining unit relative to each other along the machining feed direction in a direction parallel to the holding surface, A rotating unit that can rotate the chuck table about a rotation axis aligned perpendicular to the holding surface, The system comprises a chuck table, a machining unit, a machining feed unit, a rotation unit, and a control unit for controlling these units. The control unit, while moving the chuck table and the machining unit relative to each other along the machining feed direction with the machining feed unit, causes the machining unit to machine the workpiece from one end of the street to the other, and if machining is interrupted while an unmachined area remains, the control unit rotates the chuck table 180 degrees with the rotation unit, and while moving the chuck table and the machining unit relative to each other along the machining feed direction with the machining feed unit, causes the machining unit to machine the unmachined area of ​​the workpiece from the other end of the street. The processing apparatus is characterized in that the control unit has an abnormality detection unit that detects abnormalities that occur while the workpiece is being processed by the processing unit, and interrupts the processing of the workpiece by the processing unit when the abnormality detection unit detects the abnormality.

5. The system further comprises an imaging unit for imaging the workpiece held by the chuck table, The processing apparatus according to claim 4, characterized in that the abnormality detection unit causes the imaging unit to image the position of the workpiece processed by the processing unit, and detects the abnormality based on the image acquired by the imaging unit.

Images