Processing device and method for detecting abnormalities in proximity sensors

Abstract

To provide a processing device which prevents a function stop of a proximity sensor during processing of a workpiece by monitoring a state of the proximity sensor used for detecting a frame unit, and to provide an abnormality detection method.SOLUTION: The present invention relates to a processing device comprising: a cassette stage on which a cassette storing a frame unit 11 including an annular frame 9 and a workpiece therein is placed; a temporary placement unit 10 including a pair of frame guide rails 8; a first conveyance unit 14 which holds the frame unit 11 and conveys it to the temporary placement unit 10; and a control unit which controls the components. The temporary placement unit 10 includes a non-contact proximity sensor 8d. The control unit includes: a distance identification section for identifying a detection distance 8f at a time point, in which the proximity sensor 8d detects the frame unit 11, when conveying the frame unit 11 to the frame guide rails 8; and a determination section for determining that the proximity sensor 8d is abnormal when the detection distance 8f is shorter than a determination threshold 8e.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a processing apparatus that can be used in a device chip manufacturing method for manufacturing device chips by processing a workpiece such as a wafer formed from a material such as a semiconductor, and to a method for detecting an abnormality in a proximity sensor used in the processing apparatus. [Background technology]

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers, first, multiple intersecting dividing lines (streets) are set on the surface of a wafer made of a material such as a semiconductor. Then, devices such as integrated circuits (ICs) and large-scale integrated circuits (LSIs) are formed in each area defined by the dividing lines. The wafer is then ground from the back side to thin it, and divided along the dividing lines to form individual device chips.

[0003] The wafer is divided, for example, by a cutting device equipped with an annular cutting blade. The cutting device includes a chuck table capable of holding the wafer to be processed and a cutting unit equipped with a cutting blade and capable of cutting the wafer held on the chuck table. Alternatively, the wafer is divided by a laser processing device capable of laser processing the wafer.

[0004] When a wafer is loaded into a processing device such as a cutting device or a laser processing device, a tape called dicing tape, which has a larger diameter than the wafer, is attached to the back side of the wafer in advance, and the outer periphery of the tape is attached to an annular frame having an opening with a larger diameter than the wafer. In other words, the wafer, tape, and frame are integrated to form a frame unit (see Patent Document 1). Then, the wafer in the frame unit state is loaded into the processing device and processed.

[0005] In order to process multiple wafers continuously in the processing device, a cassette containing multiple frame units is loaded into the processing device. Then, in the processing device, the frame units are drawn out one by one from the cassette and transported to the chuck table while their positions are adjusted. The processing device is equipped with a temporary storage unit having a pair of frame guide rails, a carry-in / out unit that grips the frame units stored in the cassette and draws them out to the temporary storage unit, and a transport unit that transports the frame units placed in the temporary storage unit.

[0006] The pair of frame guide rails of the temporary placement unit can move in a direction widening or narrowing the gap between them. The temporary placement unit adjusts the position of the frame unit by sandwiching the frame unit between the pair of frame guide rails (see Patent Document 2). The temporary placement unit also includes a proximity sensor formed by a reflective photoelectric sensor or the like to detect the presence or absence of the temporarily placed frame unit. The processing device operates each unit by referring to the detection result of the presence or absence of the frame unit by the proximity sensor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 11-330008 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-7058 Summary of the Invention [Problem to be solved by the invention]

[0008] Proximity sensors deteriorate over repeated use of the processing equipment, eventually failing to perform at the required level. Proximity sensors can also break down or become blocked by foreign matter. In these cases, the proximity sensor cannot properly detect the presence or absence of a frame unit, causing the processing equipment to stop operating normally while processing the workpiece.

[0009] When a processing device stops due to a malfunction of a proximity sensor, the malfunction can be resolved by replacing or cleaning the proximity sensor. However, since the processing device must be stopped until the work is completed, the processing efficiency of the processing device for the workpieces decreases, resulting in a problem of reduced productivity. For example, if the status of the proximity sensor can be monitored and the proximity sensor can be replaced during regular maintenance work on the processing device before a malfunction actually occurs, the processing device will not stop while processing the workpieces.

[0010] The present invention has been made in consideration of such problems, and its purpose is to provide a processing device and a method for detecting abnormalities in a proximity sensor that monitors the status of the proximity sensor used to detect the frame unit, thereby preventing malfunctions due to a malfunction of the proximity sensor from occurring during processing of the workpiece. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided a cassette stage on which a cassette is placed that stores frame units arranged in a shelf-like manner, each frame unit including an annular frame, a tape affixed to the frame so as to close an opening of the frame, and a workpiece to which the tape is affixed in the opening of the frame; a temporary storage unit having a pair of frame guide rails extending in a direction away from the cassette stage and on which the frame unit is placed; a carry-in / out unit that carries the frame unit out of the cassette placed on the cassette stage and temporarily places it in the temporary storage unit, or carries the frame unit temporarily placed in the temporary storage unit into the cassette placed on the cassette stage; a chuck table that can hold the frame unit; a transport unit that holds the frame unit temporarily placed in the temporary storage unit and transports it to the chuck table, or holds the frame unit and transports it to the temporary storage unit; a processing device comprising: a processing unit that processes the workpiece contained in the workpiece; and a control unit that controls each component, wherein the temporary placement unit has a non-contact proximity sensor for detecting whether the frame unit is temporarily placed on the frame guide rail; the transport unit is supported by a lifting unit so that it can be raised and lowered above the frame guide rail; and the control unit has: a distance specifying unit that specifies the detection distance of the proximity sensor and the frame unit at the time the proximity sensor detects the frame unit when the transport unit holding the frame unit is lowered by the lifting unit to transport the frame unit to the frame guide rail; a threshold memory unit that stores a judgment threshold set to a distance at which the proximity sensor can detect the frame unit held by the transport unit; and a judgment unit that determines that the proximity sensor is abnormal when the detection distance specified by the distance specifying unit is shorter than the judgment threshold stored in the threshold memory unit.

[0012] Preferably, the control unit further includes an alarm unit, and the control unit further includes a warning unit that causes the alarm unit to issue a warning when the determination unit determines that the proximity sensor is abnormal.

[0013] Preferably, the proximity sensor is a reflective photoelectric sensor that detects whether the frame unit is temporarily placed on the frame guide rail by irradiating light onto the frame and detecting the light reflected by the frame.

[0014] According to another aspect of the present invention, there is provided an abnormality detection method for determining whether or not there is an abnormality in a proximity sensor in a processing device, the processing device including: a cassette stage on which is placed a cassette for arranging and accommodating frame units in a shelf-like manner, the frame units including an annular frame, tape affixed to the frame so as to close an opening of the frame, and a workpiece to which the tape is affixed in the opening of the frame; a temporary placement unit having a pair of frame guide rails extending in a direction away from the cassette stage and on which the frame unit is placed; a carry-in / out unit for unloading the frame unit from the cassette placed on the cassette stage and temporarily placing it on the temporary placement unit, or for loading the frame unit temporarily placed on the temporary placement unit into the cassette placed on the cassette stage; a chuck table capable of holding the frame unit; and a processing unit that processes the workpiece included in the frame unit held by the chuck table, wherein the temporary placement unit has a non-contact proximity sensor for detecting whether the frame unit is temporarily placed on the frame guide rail, and the method includes a frame holding step of having the transport unit hold the frame, a lowering step of lowering the transport unit from above the frame guide rail after the frame holding step, a detection distance specifying step of having the proximity sensor perform a detection operation of the frame during the lowering step, and specifying the distance of the frame from the proximity sensor when the proximity sensor detects the frame, and a determination step of determining that there is an abnormality in the proximity sensor if the distance of the frame from the proximity sensor when the proximity sensor detects the frame specified in the detection distance specifying step is shorter than a determination threshold. [Effects of the Invention]

[0015] In a processing device and an anomaly detection method according to one aspect of the present invention, the presence or absence of an anomaly in a proximity sensor of a temporary placement unit is determined. When the sensitivity of the proximity sensor decreases due to deterioration or the like, the distance at which the proximity sensor can detect the presence or absence of a frame of a frame unit becomes shorter. Therefore, by monitoring the distance at which the proximity sensor can detect a frame, it is possible to determine the tendency of the proximity sensor to deteriorate. Then, when the distance at which the proximity sensor detects a frame falls below a determination threshold, it is determined that an anomaly exists in the proximity sensor.

[0016] In this case, it is possible to take action before the proximity sensor is no longer able to detect the frame of the frame unit placed on the temporary storage unit. For example, by cleaning or replacing the proximity sensor at the timing of periodic maintenance performed on the processing device, it is possible to prevent the processing device from stopping functioning during processing of the workpiece due to a malfunction of the proximity sensor.

[0017] Therefore, according to one aspect of the present invention, a processing device and a method for detecting abnormalities in a proximity sensor are provided that monitor the status of a proximity sensor used to detect a frame unit, thereby preventing malfunctions due to a malfunction of the proximity sensor from occurring during processing of a workpiece. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view schematically showing a frame unit. [Figure 2] FIG. 2 is a perspective view schematically showing a processing device. [Figure 3] FIG. 2 is a perspective view schematically showing a temporary placement unit, a cassette, and a carry-in / out unit. [Figure 4] FIG. 2 is a perspective view schematically showing a frame unit transported by a transport unit. [Figure 5] FIG. 5(A) is a cross-sectional view schematically showing a frame unit temporarily placed on a temporary placement unit, and FIG. 5(B) is a cross-sectional view schematically showing a descending step. [Figure 6] 10 is a flowchart showing the flow of each step of a method for detecting an abnormality in a proximity sensor. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to the accompanying drawings. A processing apparatus according to this embodiment processes a workpiece such as a semiconductor wafer. First, the workpiece processed by the processing apparatus will be described. FIG. 1 is a perspective view schematically showing a frame unit 11. The frame unit 11 includes a workpiece 1.

[0020] The workpiece 1 is, for example, a substantially disk-shaped wafer made of a material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor. Alternatively, the workpiece 1 may be a substrate made of a material such as sapphire, glass, or quartz. The workpiece 1 may also be a package substrate containing multiple device chips sealed with a mold resin or the like.

[0021] The surface 1a of the workpiece 1 is divided by, for example, a plurality of mutually intersecting division lines 3 called streets. Devices 5 such as ICs (Integrated Circuits) and LSIs (Large-Scale Integrated Circuits) are formed in each area of ​​the surface 1a of the workpiece 1 divided by the division lines 3. When the workpiece 1 is divided along the division lines 3, individual device chips can be formed.

[0022] However, the workpiece 1 processed by the processing apparatus according to this embodiment is not limited to this, and devices may not be formed on the surface 1a. Below, an example will be described in which the workpiece 1 is a wafer on which a plurality of devices 5 are formed and which is to be divided along the planned dividing lines 3.

[0023] Before the workpiece 1 is loaded into the processing device, as shown in Fig. 1, the workpiece 1 is integrated with an annular frame 9 and tape 7 attached so as to cover an opening 9a of the frame 9, forming a frame unit 11. The frame 9 is made of a metal material such as aluminum or stainless steel, and the diameter of the opening 9a is larger than the diameter of the workpiece 1. The tape 7 has a base layer and an adhesive layer provided on the base layer, and is also called a dicing tape.

[0024] The frame unit 11 is formed by adhering the back surface 1b of the workpiece 1 to the tape 7 exposed in the opening 9a of the frame 9. At this time, the front surface 1a of the workpiece 1 is exposed upward. The workpiece 1, which is adhered to the tape 7 and attached to the frame 9 via the tape 7, is carried into a processing device in this state and processed. When the workpiece 1 is divided by the processing device, the individual chips formed are supported by the tape 7. Forming the frame unit 11 makes it easier to handle the workpiece 1 and the chips.

[0025] When the frame unit 11 containing the workpiece 1 divided into individual chips is carried out of the processing device and the tape 7 is expanded radially outward inside the opening 9a of the frame 9, the spacing between the individual chips increases, making it easier to pick up the chips. Each component of the processing device is configured to be able to handle the frame unit 11, and processes the workpiece 1 that has become part of the frame unit 11.

[0026] Next, the configuration of the processing device according to this embodiment will be described. The processing device 2 according to this embodiment is a processing device such as a cutting device that cuts the workpiece 1 that has become a frame unit 11, or a laser processing device that laser processes the workpiece 1. Below, the processing device according to this embodiment will be described using the case where the processing device according to this embodiment is a cutting device as an example.

[0027] 2 is a perspective view schematically showing a processing device (cutting device) 2. A cassette stage 6 on which a cassette 6a containing a plurality of frame units 11 is placed is provided at a corner of a base 4 of the processing device 2. The cassette stage 6 can be raised and lowered in the vertical direction (Z-axis direction).

[0028] In FIG. 2, the outline of the cassette 6a placed on the cassette stage 6 is shown by a two-dot chain line. Also, FIG. 3 includes a perspective view showing the cassette 6a in a schematic manner. The cassette 6a is a box-shaped storage case with an internal storage space. The cassette 6a stores a plurality of frame units 11. The frame units 11 are carried into and out of the processing device 2 while stored in the cassette 6a.

[0029] A plurality of storage rails 6d extending horizontally from a loading / unloading opening 6c of the cassette 6a are disposed on the inner surfaces of both side walls 6b of the cassette 6a. The storage rails 6d are formed at the same height on both side walls 6b of the cassette 6a. When the ends of the frame 9 of the frame unit 11 are placed on a pair of storage rails 6d at the same height, the frame unit 11 can be stored in the cassette 6a. The frame unit 11 can then be loaded and unloaded through the loading / unloading opening 6c.

[0030] A temporary placement unit 10 on which a frame unit 11 drawn out from a cassette 6a is temporarily placed is provided at a position adjacent to the cassette stage 6 on the upper surface of the base 4. The temporary placement unit 10 has a pair of frame guide rails 8 extending in a direction away from the cassette stage 6 (Y-axis direction), and the frame unit 11 is placed on the pair of frame guide rails 8.

[0031] Each of the pair of frame guide rails 8 has a substantially L-shaped cross section. The upper surfaces of the frame guide rails 8 serve as mounting surfaces 8a on which the frames 9 of the frame unit 11 are placed. Each frame guide rail 8 also has an upright portion 8b on the outer side in the direction perpendicular to the extension direction (X-axis direction).

[0032] The frame guide rails 8 move toward and away from each other while maintaining a parallel state in the Y-axis direction. The position of the frame 9 can be adjusted by placing the frame unit 11 on the mounting surfaces 8a of the frame guide rails 8 and moving the pair of frame guide rails 8 toward each other to sandwich the frame 9 between the upright portions 8b of the frame guide rails 8.

[0033] A carry-in / out unit 12 that carries out the frame unit 11 stored in the cassette 6a placed on the cassette stage 6 from the cassette 6a is provided at a position adjacent to the temporary placement unit 10 on the upper surface of the base 4. The carry-in / out unit 12 includes a main body 12a that is movable along the Y-axis direction, and a gripper 12b provided on the surface of the main body 12a facing the cassette stage 6.

[0034] The carry-in / out unit 12 can move the frame unit 11 between the cassette 6a and the temporary placement unit 10 by moving the main body 12a while gripping the frame 9 of the frame unit 11 with the gripping portion 12b.

[0035] For example, the main body 12a is brought close to the cassette 6a, and the frame unit 11 housed in the cassette 6a placed on the cassette stage 6 is gripped by the gripping portion 12b. Then, by moving the main body 12a in a direction away from the cassette 6a, the carry-in / out unit 12 can carry out the frame unit 11 from the cassette 6a and temporarily place it in the temporary placement unit 10.

[0036] Also, for example, by gripping the frame 9 of the frame unit 11 temporarily placed on the temporary placement unit 10 with the gripping portion 12b and moving the main body portion 12a toward the cassette 6a, the frame unit 11 can be carried into the cassette 6a placed on the cassette stage 6. Note that the height of the cassette 6a is adjusted in advance by raising and lowering the cassette stage 6 so that the height of the storage rail 6d, which is the target for loading and unloading the frame unit 11, matches the height of the loading / unloading unit 12.

[0037] An opening 4a that is long in the X-axis direction (front-rear direction, processing feed direction) is formed at a position adjacent to the cassette stage 6 on the top surface of the base 4. A ball screw type X-axis movement mechanism (processing feed unit) (not shown) and a bellows-shaped dustproof and drip-proof cover 26 that covers the top of the X-axis movement mechanism are disposed within the opening 4a.

[0038] The X-axis movement mechanism is connected to the lower part of the X-axis movement table 16 and has the function of moving the X-axis movement table 16 in the X-axis direction. For example, the X-axis movement table 16 moves between a loading / unloading area adjacent to the cassette stage 6 and a processing area below the processing unit 32 described below.

[0039] A table base 18 and a chuck table 20 mounted on the table base 18 are provided on the X-axis moving table 16. The chuck table 20 has the function of holding the frame unit 11 while the workpiece 1 included in the frame unit 11 is being machined.

[0040] A porous plate (not shown) is provided on top of the chuck table 20, and one end of a suction path (not shown) formed in the chuck table 20 is connected to the porous plate. The other end of the suction path is connected to a suction source (not shown). When the suction source is operated, negative pressure is generated on the surface of the porous plate. As a result, the surface of the porous plate functions as a holding surface 22 that holds the workpiece 1 by suction via the tape 7.

[0041] A rotation drive mechanism (not shown) that rotates the chuck table 20 around a predetermined rotation axis is provided below the chuck table 20. Clamps 24 that grip the frame 9 are provided radially outward of the chuck table 20. The chuck table 20 moves in the X-axis direction by the X-axis movement mechanism described above.

[0042] The frame unit 11 is transported from the temporary placement unit 10 to the chuck table 20 by a first transport unit 14 provided at a position adjacent to the temporary placement unit 10 and the opening 4a on the upper surface of the base 4. That is, the first transport unit 14 has a function of holding the frame unit 11 temporarily placed on the temporary placement unit 10 and transporting it to the chuck table 20. Furthermore, the first transport unit 14 has a function of holding the frame unit 11 placed on the chuck table 20 and transporting it to the temporary placement unit 10.

[0043] 4, the first transport unit 14 has a shaft 14a that protrudes upward from the top surface of the base 4 and is capable of lifting and rotating, an arm 14b that extends horizontally from the upper end of the shaft 14a, and a holder 14c that is provided below the tip of the arm 14b. The base 4 houses a transport drive source 14d that functions as both an elevation unit that lifts and lowers the shaft 14a and a rotation unit that rotates the shaft 14a. The lower end of the holder 14c is connected to a suction mechanism (not shown), and the holder 14c has the function of suction-holding the frame 9 from above.

[0044] When the transport drive source 14d is operated to rotate the shaft 14a, the holder 14c can move between above the frame guide rails 8 of the temporary storage unit 10 and above the chuck table 20 positioned in the carry-in / out area. When the transport drive source 14d is operated to raise and lower the shaft 14a, the holder 14c can be raised and lowered. In other words, the first transport unit 14 is supported by the transport drive source 14d, which functions as a lifting unit, so that it can be raised and lowered above the frame guide rails 8 and above the chuck table 20.

[0045] When the frame unit 11 is transported from the temporary placement unit 10 to the chuck table 20 by the first transport unit 14, the X-axis moving table 16 is moved to position the chuck table 20 in the carry-in / out area. Then, the transport drive source 14d is operated to rotate the shaft portion 14a, and the holding portion 14c is moved above the frame unit 11 temporarily placed on the temporary placement unit 10. The shaft portion 14a is then lowered to bring the holding portion 14c into contact with the frame 9.

[0046] Next, the suction mechanism connected to the holder 14c is activated to suck and hold the frame unit 11 (frame 9) from above. After that, the transport drive source 14d is activated again to raise the shaft 14a, which lifts the frame unit 11 that is sucked and held by the holder 14c. Then, the shaft 14a is rotated to move the frame unit 11 above the chuck table 20, and the shaft 14a is lowered to place the frame unit 11 on the chuck table 20.

[0047] Then, the frame 9 is fixed with the clamps 24, and the workpiece 1 is suction-held by the chuck table 20 via the tape 7 of the frame unit 11. Then, the suction-holding of the frame 9 by the holding portion 14c is released, and the holding portion 14c is moved. In this way, the frame unit 11, which has been drawn out of the cassette 6a, temporarily placed on the temporary placement unit 10, and has had its position adjusted, is transported to the chuck table 20 that can hold the frame unit 11.

[0048] The processing device 2 includes a support structure 28 disposed above the movement path of the X-axis moving table 16 from the carry-in / out area to the processing area, so as to cross the opening 4a. An imaging unit 30 facing downward is provided on the support structure 28. The imaging unit 30 includes an imaging element such as a CMOS sensor or a CCD sensor, and captures an image of the workpiece 1 included in the frame unit 11 from above, and detects the position and orientation of the planned dividing line 3 set on the surface 1a of the workpiece 1.

[0049] In the processing area where the workpiece 1 is processed (cut), a processing unit (cutting unit) 32 is provided that processes (cuts) the workpiece 1 of the frame unit 11 held by the chuck table 20. In the following, an example will be described in which the processing unit 32 is a cutting unit that cuts the workpiece 1, but the processing unit 32 is not limited to this.

[0050] The processing unit 32 that cuts the workpiece 1 includes a cutting blade 34 with a circular cutting edge on its outer periphery, and a spindle 36 that has the cutting blade 34 attached to its tip and that runs along the Y-axis direction and serves as the rotation axis of the cutting blade 34.

[0051] A rotary drive source (not shown), such as a motor, is connected to the base end of the spindle 36, and the cutting blade 34, which is attached to one end of the spindle 36, rotates by the force generated by this rotary drive source. The cutting blade 34 includes an annular base made of aluminum or the like, and an annular cutting blade fixed to the outer periphery of the base. The cutting blade is formed, for example, by fixing abrasive grains, such as diamond, with a binder, such as resin or metal.

[0052] The processing device 2 also includes an indexing feed unit (not shown) inside the support structure 28 that moves the processing unit 32 along an indexing feed direction (Y-axis direction) perpendicular to the processing feed direction (X-axis direction). When the processing feed unit and the indexing feed unit are operated, the chuck table 20 that holds the workpiece 1 by suction and the processing unit 32 can be moved relative to each other.

[0053] The cutting blade 34 is rotated and cuts into the workpiece 1 along the planned dividing lines 3, cutting the workpiece 1 and forming dividing grooves. When the workpiece 1 has been cut along all of the planned dividing lines 3, the workpiece 1 is divided into individual device chips. Thereafter, the chuck table 20 is moved to the loading / unloading area by the X-axis movement mechanism.

[0054] An opening 4b is formed on the upper surface of the base 4 at a position adjacent to the temporary placement unit 10 and the opening 4a, and the opening 4b houses a cleaning unit 38 that cleans the frame unit 11 after processing. The cleaning unit 38 is equipped with a spinner table that holds the frame unit 11.

[0055] The processing device 2 includes a second transport unit 40 that transports the frame unit 11 from the chuck table 20 positioned in the loading / unloading area to the cleaning unit 38. The second transport unit 40 has an arm that is movable along the Y-axis direction and a holder provided below the tip of the arm.

[0056] When the second transport unit 40 transports the frame unit 11 from the chuck table 20 to the cleaning unit 38, the frame unit 11 is first held by the holding portion. Then, the arm portion is moved along the Y-axis direction to place the frame unit 11 on the spinner table of the cleaning unit 38. Thereafter, the frame unit 11 is held by the spinner table and the workpiece 1 is cleaned.

[0057] When cleaning the workpiece 1 in the cleaning unit 38, a cleaning fluid (typically a mixed fluid of water and air) is sprayed onto the surface of the workpiece 1 while the spinner table is rotating. Then, when the supply of the cleaning fluid is stopped while the spinner table continues to rotate, the frame unit 11 can be dried. The frame unit 11 cleaned in the cleaning unit 38 is transferred from the cleaning unit 38 to the temporary placement unit 10 by the first transport unit 14.

[0058] That is, the first transport unit 14 operates the transport drive source 14d to bring the holder 14c into contact with the frame 9 of the frame unit 11 placed on the spinner table of the cleaning unit 38, and the holder 14c suction-holds the frame unit 11. Then, the transport drive source 14d is operated to transport the frame unit 11 to the temporary placement unit 10. Thereafter, the holder 14c releases the suction-holding of the frame 9. The frame unit 11 is then temporarily placed on the temporary placement unit 10.

[0059] The frame unit 11, which has been returned to and temporarily placed in the temporary placement unit 10, is carried into the cassette 6a placed on the cassette stage 6 by the carry-in / out unit 12. As described above, in the processing device 2, the frame unit 11 housed in the cassette 6a and carried into the processing device 2 is pulled out from the cassette 6a and transferred to the chuck table 20. Then, the workpiece 1 is processed in the processing unit 32, and after being cleaned in the cleaning unit 38, the frame unit 11 is returned to the cassette 6a.

[0060] The processing device 2 includes a control unit 42. The control unit 42 is connected to each component of the processing device 2 and has the function of controlling each component. The control unit 42 is configured by a computer including, for example, a processing device such as a CPU (Central Processing Unit), a main storage device such as a DRAM (Dynamic Random Access Memory), and an auxiliary storage device such as a flash memory. The functions of the control unit 42 are realized by operating the processing device and the like in accordance with software stored in the auxiliary storage device.

[0061] The processing conditions for processing the workpiece 1 are input and registered in advance in the control unit 42. The control unit 42 then controls each component in accordance with the processing conditions. The processing conditions are set appropriately according to the type of workpiece and the desired processing results. The control unit 42 then controls each component while referring to the information sent from each component, and processes the workpiece 1 in a predetermined procedure.

[0062] Here, the temporary placement unit 10 has a non-contact proximity sensor 8d for detecting whether or not the frame unit 11 (frame 9) is temporarily placed on the frame guide rail 8, as shown in FIG.

[0063] Fig. 5(A) is a cross-sectional view that schematically shows the frame unit 11 temporarily placed on the temporary placement unit 10, and Fig. 5(A) also includes a side view that schematically shows the frame guide rail 8 on one side of the temporary placement unit 10. Furthermore, Fig. 5(A) shows, by dashed lines, a through-hole 8c formed in the frame guide rail 8 and a proximity sensor 8d that detects the frame unit 11 (frame 9) placed on the placement surface 8a of the frame guide rail 8 through the through-hole 8c.

[0064] The proximity sensor 8d is, for example, a reflective photoelectric sensor that detects whether the frame unit 11 is temporarily placed on the frame guide rail 8 by irradiating light onto the frame 9 of the frame unit 11 and detecting the light reflected by the frame 9. The proximity sensor 8d has a light-emitting unit (not shown) that irradiates light toward the frame 9 of the frame unit 11, and a light-receiving unit (not shown) that receives the light reflected by the frame 9 of the frame unit 11.

[0065] Preferably, the proximity sensor 8d is a limited reflection type photoelectric sensor. In a limited reflection type photoelectric sensor, the light-emitting unit emits light at a predetermined angle and the light-receiving unit receives the light at a predetermined angle, so that when the frame unit 11 (frame 9) to be detected is located a predetermined distance from the proximity sensor 8d, the frame 9 is likely to be detected by the proximity sensor 8d. The proximity sensor 8d is fixed in a position where it can easily detect the frame unit 11 (frame 9) placed on the mounting surface 8a of the frame guide rail 8.

[0066] The proximity sensor 8d detects the frame unit 11 (frame 9) when the frame unit 11 approaches within a predetermined distance, and stops detecting the frame unit 11 when the frame unit 11 moves further away than the predetermined distance. The proximity sensor 8d is connected to the control unit 42, and continues to send an electrical signal indicating the detection status of the frame unit 11 to the control unit 42. The control unit 42 controls each component while referring to information regarding whether the proximity sensor 8d is detecting the frame unit 11, and performs tasks such as transporting the frame unit 11.

[0067] Here, the proximity sensor 8d can detect the frame unit 11 (frame 9) at a relatively long distance in the early stages of use. That is, the detection limit distance of an unused proximity sensor 8d is relatively long. Then, the proximity sensor 8d deteriorates as the processing device 2 is repeatedly operated, and the detection limit distance of the frame 9 gradually shortens. Eventually, even if the frame unit 11 (frame 9) is placed on the mounting surface 8a of the frame guide rail 8, the proximity sensor 8d will no longer be able to detect the frame unit 11.

[0068] Furthermore, the proximity sensor 8d may malfunction during use. Furthermore, if water droplets or processing debris adhere to the light-emitting or light-receiving portion, the proximity sensor 8d may continue to erroneously detect the frame unit 11 even when the frame unit 11 (frame 9) is not placed on the frame guide rail 8. In these cases, the proximity sensor 8d cannot properly detect the presence or absence of the frame unit 11, and the processing device 2 may stop operating normally while processing the workpiece 1.

[0069] When the processing device 2 stops due to a malfunction of the proximity sensor 8d, the malfunction can be resolved by replacing the proximity sensor 8d with a new one or cleaning the proximity sensor 8d using an air gun, etc. However, since the processing device 2 must be stopped until the work is completed, a new problem arises in that the processing efficiency of the workpiece 1 in the processing device 2 decreases, resulting in a decrease in productivity.

[0070] Therefore, the processing device 2 according to this embodiment monitors the state of the proximity sensor 8d used to detect the frame unit 11, thereby preventing a malfunction of the proximity sensor 8d from occurring during processing of the workpiece 1. For example, an abnormality in the proximity sensor 8d is detected before the proximity sensor 8d malfunctions, and the proximity sensor 8d is replaced during regular maintenance work on the processing device 2. In this case, there is no need to stop operation of the processing device 2 due to a malfunction of the proximity sensor 8d during processing of the workpiece 1, and processing efficiency does not decrease.

[0071] Below, we will continue to explain the processing device 2, focusing on the configuration related to monitoring the state of the proximity sensor 8d. Monitoring the state of the proximity sensor 8d is mainly achieved by the function of the control unit 42. Figure 2 is a block diagram showing the configuration that contributes to the control unit 42 monitoring the state of the proximity sensor 8d.

[0072] The control unit 42 includes a distance determination unit 42b that determines the detection distance between the proximity sensor 8d and the frame unit 11 (frame 9) at the time when the proximity sensor 8d detects the frame unit 11. The distance determination unit 42b can determine the height of the frame unit 11 held by the holding unit 14c of the first transport unit 14 from the operating status of the transport drive source 14d that functions as a lifting unit.

[0073] 5(B) is a cross-sectional view that schematically shows the frame unit 11 being transported to the frame guide rail 8 by the first transport unit 14. For example, the proximity sensor 8d detects the frame unit 11 when the first transport unit 14, which holds the frame unit 11, is lowered by the transport drive source 14d that functions as an elevation unit to transport the frame unit 11 to the frame guide rail 8.

[0074] Then, the distance determination unit 42b determines the detection distance between the proximity sensor 8d and the frame unit 11 at the time when the proximity sensor 8d detects the frame unit 11. In Fig. 5(B), the detection distance 8f when the proximity sensor 8d detects the frame unit 11 is schematically shown by an arrow. The distance determination unit 42b determines this detection distance 8f.

[0075] The control unit 42 determines whether or not there is an abnormality in the proximity sensor 8d using this detection distance 8f. That is, a determination threshold for determining whether or not there is an abnormality in the proximity sensor 8d is set in the detection distance 8f. In Fig. 5(B), the determination threshold 8e is schematically indicated by a dashed arrow.

[0076] The control unit 42 has a threshold memory 42a that stores a determination threshold 8e set to a distance at which the proximity sensor 8d can detect the frame unit 11 (frame 9) held by the first transport unit 14. The control unit 42 also has a determination unit 42c that determines that the proximity sensor 8d is abnormal when the detection distance 8f specified by the distance specification unit 42b is shorter than the determination threshold 8e stored in the threshold memory 42a.

[0077] For example, the mounting surface 8a of the frame guide rail 8 is set at a position about 3 mm higher than the proximity sensor 8d. Therefore, if the detection distance 8f of the proximity sensor 8d becomes shorter than 3 mm, the proximity sensor 8d will not be able to detect the frame unit 11 even if the frame unit 11 is mounted on the frame guide rail 8.

[0078] For example, the detection distance 8f of an unused proximity sensor 8d is about 11 mm. That is, immediately after starting use, the proximity sensor 8d detects the frame unit 11 (frame 9) when the frame unit 11 held by the holding portion 14c of the first transport unit 14 approaches a height position about 8 mm above the mounting surface 8a of the frame guide rail 8.

[0079] In this case, for example, the determination threshold 8e set to the distance detectable by the proximity sensor 8d may be set to 7 mm. That is, the determination unit 42c may determine that the proximity sensor 8d is abnormal when the detection distance 8f specified by the distance specification unit 42b is shorter than the determination threshold 8e of 7 mm. In other words, if the proximity sensor 8d does not detect the frame unit 11 even when the frame unit 11 approaches to the placement surface 8a within a distance of 4 mm, the determination unit 42c determines that the proximity sensor 8d is abnormal.

[0080] If it is determined that the proximity sensor 8d is abnormal, cleaning or replacing the proximity sensor 8d can be performed during the first maintenance work performed on the processing device 2 thereafter, thereby preventing the processing device 2 from stopping due to a malfunction of the proximity sensor 8d while processing the workpiece 1. Therefore, the operating time of the processing device 2 is not reduced, and the processing efficiency of the processing device 2 for the workpiece 1 is maintained.

[0081] In addition, the processing device 2 may have an alarm unit (not shown) that notifies the user or administrator of various warnings, and the control unit 42 may further include an alarm unit 42d that causes the alarm unit to issue a warning when the judgment unit 42c determines that the proximity sensor 8d is abnormal.

[0082] For example, the notification unit is a display with a touch panel that is provided on the exterior of the processing device 2 and can display various information and is used to input various commands. Alternatively, the notification unit may be an alarm lamp or a speaker that can emit a warning sound that is provided on the exterior of the processing device 2. However, the notification unit is not limited to these.

[0083] When the determination unit 42c determines that the proximity sensor 8d is abnormal, the warning unit 42d, for example, displays warning information on a touch panel display functioning as a notification unit, or turns on an alarm lamp functioning as a notification unit to notify of the abnormality, or causes a speaker functioning as a notification unit to emit an alarm sound.

[0084] When a user or manager of the processing device 2 receives a warning from the alarm unit, the user or manager prepares to replace or clean the proximity sensor 8d the next time maintenance is performed on the processing device 2. By taking the prescribed measures during maintenance, it is possible to prevent the processing device 2 from being shut down due to a malfunction of the proximity sensor 8d.

[0085] Finally, the procedure for the abnormality detection method for determining whether or not there is an abnormality in the proximity sensor 8d in the processing device 2 will be summarized. Fig. 6 is a flowchart showing the flow of each step of the abnormality detection method for determining whether or not there is an abnormality in the proximity sensor 8d in the processing device 2.

[0086] First, a frame holding step S10 is performed in which the frame 9 is held by the carrying unit (first carrying unit 14). For example, the frame 9 of the frame unit 11 placed on the chuck table 20 is held by the holding portion 14c of the first carrying unit 14. Alternatively, the frame 9 of the frame unit 11 placed on the frame guide rail 8 is held by the holding portion 14c of the first carrying unit 14.

[0087] After the frame holding step S10, a lowering step S20 is performed in which the transport drive source 14d, which functions as a lifting unit, is operated to lower the transport unit (first transport unit 14) from above the frame guide rail 8. Furthermore, during the lowering step S20, the proximity sensor 8d is made to perform a detection operation for the frame 9, and a detection distance specifying step S30 is performed in which the distance of the frame 9 from the proximity sensor 8d when the proximity sensor 8d detects the frame 9 is specified.

[0088] 5(B) is a cross-sectional view schematically showing the lowering step S20 and the detection distance specifying step S30. For example, the detection operation of the proximity sensor 8d is performed while the frame unit 11 is lowered from above the frame guide rail 8 at a speed of about 0.5 mm per second. Then, the distance from the proximity sensor 8d to the frame 9 when the proximity sensor 8d detects the frame 9 of the frame unit 11 is specified.

[0089] Next, a determination step S40 is performed to determine whether or not there is an abnormality in the proximity sensor 8d based on the distance from the proximity sensor 8d to the frame 9 when the proximity sensor 8d detected the frame 9, which was specified in the detection distance determination step S30. If the distance from the proximity sensor 8d to the frame 9 is shorter than the determination threshold, it is determined that there is an abnormality in the proximity sensor 8d. On the other hand, if the distance from the proximity sensor 8d to the frame 9 is equal to or greater than the determination threshold, it is determined that there is no abnormality in the proximity sensor 8d.

[0090] If it is determined in the determination step S40 that there is an abnormality in the proximity sensor 8d, it is preferable to execute a warning step S50 in which the determination result is notified by a notification unit provided in the processing device 2. In this case, the user or manager of the processing device 2 can know that there is an abnormality in the proximity sensor 8d, and can therefore consider countermeasures and take action before the proximity sensor 8d malfunctions.

[0091] The present invention is not limited to the above-described embodiment and can be implemented with various modifications. For example, in the above-described embodiment, the frame unit 11 held by the holder 14c of the first transport unit 14 is gradually lowered to determine the detection distance of the proximity sensor 8d. However, one aspect of the present invention is not limited to this.

[0092] That is, in the processing device and proximity sensor anomaly detection method according to one aspect of the present invention, the detection distance of the proximity sensor 8d may be specified by having the frame unit 11 held by the second transport unit 40 instead of the first transport unit 14. That is, there is no limitation on the transport unit that holds the frame unit 11.

[0093] In the above embodiment, the frame unit 11 is lowered onto the frame guide rails 8 from above to identify the detection distance at which the proximity sensor 8d detects the frame 9, but this is not a limitation of one aspect of the present invention. For example, when the frame unit 11 placed on the frame guide rails 8 is gripped by the holder 14c of the first transport unit 14 and raised, the distance at which the proximity sensor 8d no longer detects the frame 9 may be identified as the detection distance.

[0094] Furthermore, in the above embodiment, a case has been described in which, if the determination unit 42c determines that there is an abnormality in the proximity sensor 8d, the proximity sensor 8d is cleaned or replaced the next time the operation of the processing device 2 is stopped for maintenance work in the processing device 2. However, one aspect of the present invention is not limited to this.

[0095] That is, measures such as replacing the proximity sensor 8d may not be implemented during maintenance performed immediately after an abnormality in the proximity sensor 8d is detected. For example, the control unit 42 may evaluate the progression of the abnormal state and continue to use the proximity sensor 8d for a period during which it is determined that the proximity sensor 8d is suitable for use.

[0096] In the above embodiment, the temporary placement unit 10 is described as having one proximity sensor 8d, but this aspect of the present invention is not limited to this. That is, the temporary placement unit 10 may be provided with two or more proximity sensors 8d. The presence or absence of an abnormality may be determined for each proximity sensor 8d individually.

[0097] Furthermore, in the above embodiment, when determining whether the proximity sensor 8d is abnormal, the frame unit 11 is held by the first transport unit 14 and the proximity sensor 8d detects the frame unit 11. The frame unit 11 is housed in the cassette 6a and transported, and the workpiece 1 included in the frame unit 11 is processed by the processing unit 32. However, one aspect of the present invention is not limited to this.

[0098] After the processing of the workpiece 1 is completed, the frame unit 11 is stored in the cassette 6a and carried out from the processing device 2. Then, the processed workpiece 1 is peeled off from the tape 7, and the frame unit 11 is disassembled. Here, the frame 9 included in the frame unit 11 can be reused to process a new workpiece 1, and is used to form a new frame unit 11 after a prescribed cleaning operation.

[0099] However, the frame 9 may develop small scratches on its surface or may be slightly twisted or distorted during repeated use. Furthermore, dirt may adhere to the frame 9 while the frame unit 11 is formed and the workpiece 1 is being processed. Furthermore, when the frame 9 is reused, it may not be possible to completely remove the dirt that has adhered to the frame 9. Therefore, when attempting to detect the frames 9 included in the frame unit 11 with the proximity sensor 8d, each frame 9 may not necessarily reflect the light received from the proximity sensor 8d in the same manner.

[0100] Therefore, the detection distance of the proximity sensor 8d varies depending on the state of the detection target frame 9. Therefore, in order to more stably and accurately determine whether or not the proximity sensor 8d is abnormal, in one aspect of the present invention, a determination frame that is used solely for the purpose of determining whether or not the proximity sensor 8d is abnormal may be prepared and used.

[0101] In this case, the determination frame may be housed in a cassette 6a and carried into the processing device 2. Alternatively, the determination frame may be stored near the processing device 2, and a user or manager of the processing device 2 may hold the determination frame in the holding portion 14c of the first transport unit 14 as needed. For example, if the determination frame is stored near the processing device 2, the presence or absence of an abnormality in the proximity sensor 8d can be determined using the determination frame during the short amount of time when the processing device 2 is not processing the workpiece 1.

[0102] Here, the judgment frame may be integrated with the workpiece 1 and the tape 7, or a judgment frame unit may be formed, or the judgment frame may be used in a state where it is not integrated with the workpiece 1 and the tape 7.

[0103] When the presence or absence of an abnormality in the proximity sensor 8d is determined using the determination frame, the detection distance of the proximity sensor 8d does not vary depending on the state of the frame 9, and the determination result of the determination unit 42c of the control unit 42 is not affected by the state of the frame 9. This increases the reliability of the determination result of the determination unit 42c, and proximity sensors 8d determined to be normal can be reliably used continuously. This also allows for a more precise plan for cleaning or replacing the proximity sensor 8d.

[0104] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0105] 1 Workpiece 1a surface 1b back side 3 Planned division line 5 Devices 7. Tape 9 frames 9a opening 11 Frame Unit 2 Processing equipment 4 Foundation 4a,4b opening 6. Cassette Stage 6a cassette 6b side wall 6c Loading / unloading entrance 6d Storage rail 8 Frame guide rail 8a Placement surface 8b Standing section 8c through hole 8d Proximity Sensor 8e Decision Threshold 8f detection distance 10 Temporary Unit 12 Loading / unloading unit 12a Main body 12b Grip part 14 First transport unit 14a Shaft 14b Arm 14c Holding part 14d Transport drive source 16 X-axis moving table 18 Table Base 20 Chuck table 22 Holding surface 24 Clamp 26 Dustproof and water-resistant cover 28 Support structure 30 Imaging unit 32 Processing Unit 34 Cutting blade 36 Spindle 38 Cleaning Unit 40 Second transport unit 42 Control Unit 42a Threshold memory unit 42b Distance identification part 42c Judgment part 42d Warning section

Claims

1. a cassette stage on which cassettes are placed, each of which stores frame units arranged in a shelf-like manner, each frame unit including an annular frame, a tape affixed to the frame so as to close an opening of the frame, and a workpiece to which the tape is affixed in the opening of the frame; a temporary placement unit having a pair of frame guide rails extending in a direction away from the cassette stage, on which the frame unit is placed; a carry-in / out unit that carries out the frame unit from the cassette placed on the cassette stage and temporarily places it on the temporary placement unit, or carries the frame unit temporarily placed on the temporary placement unit into the cassette placed on the cassette stage; a chuck table capable of holding the frame unit; a transport unit that holds the frame unit temporarily placed on the temporary placement unit and transports it to the chuck table, or that holds the frame unit and transports it to the temporary placement unit; a processing unit for processing the workpiece included in the frame unit held by the chuck table; A processing apparatus including a control unit that controls each component, the temporary placement unit has a non-contact proximity sensor for detecting whether the frame unit is temporarily placed on the frame guide rail; the transport unit is supported by a lifting unit so as to be able to move up and down above the frame guide rail; The control unit a distance specifying unit that specifies a detection distance of the proximity sensor and the frame unit at the time when the proximity sensor detects the frame unit when the transport unit holding the frame unit is lowered by the lifting unit to transport the frame unit onto the frame guide rail; a threshold storage unit that stores a determination threshold set at a distance at which the frame unit held by the transport unit can be detected by the proximity sensor; a determination unit that determines that the proximity sensor is abnormal when the detection distance specified by the distance specification unit is shorter than the determination threshold stored in the threshold storage unit.

2. Further comprising an alarm unit, 2. The processing device according to claim 1, wherein the control unit further comprises a warning unit that causes the notification unit to issue a warning when the determination unit determines that the proximity sensor is abnormal.

3. The processing device according to claim 1 or 2, characterized in that the proximity sensor is a reflective photoelectric sensor that detects whether the frame unit is temporarily placed on the frame guide rail by irradiating light onto the frame and detecting the light reflected by the frame.

4. An abnormality detection method for determining whether or not there is an abnormality in a proximity sensor in a processing device, comprising: The processing device is a cassette stage on which cassettes are placed, each of which stores frame units arranged in a shelf-like manner, each frame unit including an annular frame, a tape affixed to the frame so as to close an opening of the frame, and a workpiece to which the tape is affixed in the opening of the frame; a temporary placement unit having a pair of frame guide rails extending in a direction away from the cassette stage, on which the frame unit is placed; a carry-in / out unit that carries out the frame unit from the cassette placed on the cassette stage and temporarily places it on the temporary placement unit, or carries the frame unit temporarily placed on the temporary placement unit into the cassette placed on the cassette stage; a chuck table capable of holding the frame unit; a transport unit that holds the frame unit temporarily placed on the temporary placement unit and transports it to the chuck table, or that holds the frame unit and transports it to the temporary placement unit; a processing unit that processes the workpiece included in the frame unit held by the chuck table, the temporary placement unit has a non-contact proximity sensor for detecting whether the frame unit is temporarily placed on the frame guide rail, a frame holding step of causing the transport unit to hold the frame; a lowering step of lowering the transport unit from above the frame guide rail after the frame holding step; a detection distance determination step of causing the proximity sensor to perform a detection operation of the frame during the descending step, and determining a distance of the frame from the proximity sensor when the proximity sensor detects the frame; an abnormality detection method characterized by including a judgment step of judging that there is an abnormality in the proximity sensor if the distance from the proximity sensor of the frame when the proximity sensor identified in the detection distance identification step detects the frame is shorter than a judgment threshold.

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