JP7768786B2 - Processing device and method for detecting abnormalities in proximity sensors - Google Patents

Description

The present invention relates to a processing apparatus that can be used in a device chip manufacturing method for manufacturing device chips by processing workpieces such as wafers made of semiconductor materials, and to a method for detecting abnormalities in proximity sensors used in the processing apparatus.

The manufacturing process for device chips used in electronic devices such as mobile phones and personal computers begins by setting multiple intersecting dividing lines (streets) on the surface of a wafer made of a semiconductor or other material. Devices such as integrated circuits (ICs) and large-scale integration (LSIs) are then 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.

Wafer division is performed, for example, using a cutting device equipped with an annular cutting blade. The cutting device includes a chuck table that can hold the wafer to be processed, and a cutting unit that has a cutting blade and can cut the wafer held on the chuck table. Alternatively, wafer division is performed using a laser processing device that can laser process the wafer.

When a wafer is loaded into a processing device such as a cutting device or laser processing device, a tape called dicing tape, which is larger in diameter than the wafer, is first attached to the backside of the wafer, and the outer periphery of the tape is attached to an annular frame with an opening larger in diameter than the wafer. In other words, the wafer, tape, and frame are integrated to form a frame unit (see Patent Document 1). The wafer in the frame unit state is then loaded into the processing device and processed.

In order to process multiple wafers continuously using a processing device, a cassette containing multiple frame units is loaded into the processing device. The frame units are then extracted 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 loading/unloading unit that grasps the frame units stored in the cassette and extracts them into the temporary storage unit, and a transport unit that transports the frame units placed in the temporary storage unit.

The pair of frame guide rails of the temporary placement unit can be moved in directions 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, such as a reflective photoelectric sensor, to detect the presence or absence of a temporarily placed frame unit. The processing device then operates each unit based on the results of the proximity sensor's detection of the presence or absence of the frame unit.

Japanese Patent Application Publication No. 11-330008 Japanese Patent Application Laid-Open No. 2001-7058

Proximity sensors deteriorate as the processing equipment is repeatedly operated, and eventually fail to perform at the required level. Proximity sensors can also break down or become unable to function properly due to adhesions. 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.

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, because the processing device must be stopped until the work is completed, this can cause problems such as a decrease in the processing efficiency of the workpiece on the processing device, resulting in a decline in 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 a workpiece.

The present invention was made in consideration of these problems, and its purpose is to provide a processing device and a method for detecting proximity sensor abnormalities that monitor the status of the proximity sensor used to detect the frame unit, thereby preventing malfunctions due to proximity sensor malfunctions from occurring during processing of a workpiece.

According to one aspect of the present invention, there is provided a cassette stage on which a cassette is placed that stores frame units, each including an annular frame, tape affixed to the frame so as to close the opening of the frame, and a workpiece to which the tape is affixed in the opening of the frame, arranged in a shelf-like manner; 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 removes the frame unit from the cassette placed on the cassette stage and temporarily places it on the temporary storage unit, or that carries the frame unit temporarily placed on 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 on the temporary storage unit and transports it to the chuck table, or that holds the frame unit and transports it to the temporary storage unit; and a frame unit included in the frame unit held by the chuck table. The processing device includes a processing unit that processes the workpiece contained therein, and a control unit that controls each component. The temporary placement unit has a non-contact proximity sensor that detects 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. The control unit has: a distance determination unit that determines 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 determination threshold set to a distance at which the proximity sensor can detect the frame unit held by the transport unit; and a determination unit that determines that the proximity sensor is abnormal when the detection distance determined by the distance determination unit is shorter than the determination threshold stored in the threshold memory unit.

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.

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.

According to another aspect of the present invention, there is provided an anomaly detection method for determining whether or not a proximity sensor in a processing device has 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. The processing device includes a cassette stage on which a cassette is placed that stores frame units arranged 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 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 removes the frame unit from the cassette placed on the cassette stage and temporarily places it on the temporary storage unit, or that carries the frame unit temporarily placed on the temporary storage unit into the cassette placed on the cassette stage; a chuck table that can hold the frame unit; and a frame unit that holds the frame unit temporarily placed on the temporary storage unit and transports it to the chuck table. The method includes a transport unit that holds a frame unit and transports it to the temporary placement unit, and 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 that detects whether the frame unit is temporarily placed on the frame guide rail. The method includes a frame holding step in which the transport unit holds the frame, a lowering step in which the transport unit is lowered from above the frame guide rail after the frame holding step, a detection distance determination step in which the proximity sensor detects the frame during the lowering step and determines the distance from the proximity sensor to the frame when the proximity sensor detects the frame, and a determination step in which the proximity sensor is determined to have an abnormality if the distance from the proximity sensor to the frame when the proximity sensor detects the frame determined in the detection distance determination step is shorter than a determination threshold.

In one aspect of the present invention, a processing device and anomaly detection method determine whether or not there is an abnormality in the proximity sensor of the temporary placement unit. If the sensitivity of the proximity sensor decreases due to deterioration or other reasons, the distance at which the proximity sensor can detect the presence or absence of a frame of the 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 the determination threshold, it is determined that there is an abnormality in the proximity sensor.

In this case, action can be taken 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 during regular maintenance of the processing device, it is possible to prevent the processing device from stopping functioning while processing a workpiece due to a malfunction of the proximity sensor.

Therefore, one aspect of the present invention provides a processing device and a method for detecting proximity sensor abnormalities that monitor 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 a workpiece.

FIG. 2 is a perspective view schematically showing a frame unit. FIG. 2 is a perspective view schematically showing a processing device. FIG. 2 is a perspective view schematically showing a temporary placement unit, a cassette, and a carry-in/out unit. FIG. 2 is a perspective view schematically showing a frame unit transported by a transport unit. FIG. 5A is a cross-sectional view schematically showing a frame unit temporarily placed on the temporary placement unit, and FIG. 5B is a cross-sectional view schematically showing a descending step. 10 is a flowchart showing the flow of each step of a method for detecting an abnormality in a proximity sensor.

An embodiment of the present invention will be described with reference to the accompanying drawings. The 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. Figure 1 is a perspective view schematically showing a frame unit 11. The frame unit 11 includes a workpiece 1.

The workpiece 1 is, for example, a substantially circular 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 molded resin or the like.

The surface 1a of the workpiece 1 is divided by, for example, a plurality of planned division lines 3, called streets, that intersect with one another. 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 planned division lines 3. By dividing the workpiece 1 along the planned division lines 3, individual device chips can be formed.

However, the workpiece 1 processed by the processing apparatus according to this embodiment is not limited to this, and devices do not have to be formed on the surface 1a. Below, we will explain an example in which the workpiece 1 is a wafer on which multiple devices 5 are formed and which is to be divided along the planned division lines 3.

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 to cover the 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 dicing tape.

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, adhered to the tape 7 and attached to the frame 9 via the tape 7, is then loaded into the 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.

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 within the opening 9a of the frame 9, widening the spacing between the individual chips and making it easier to pick up the chips. Each component of the processing device is configured to handle the frame unit 11 and processes the workpiece 1 that has become part of the frame unit 11.

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 in the form of 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 example where the processing device according to this embodiment is a cutting device.

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

In Figure 2, the outline of the cassette 6a placed on the cassette stage 6 is shown by a two-dot chain line. Also, Figure 3 includes a perspective view showing the cassette 6a in schematic form. The cassette 6a is a box-shaped storage case with an internal storage space. The cassette 6a stores multiple frame units 11. The frame units 11 are loaded into and unloaded from the processing device 2 while stored in the cassette 6a.

A number of storage rails 6d are arranged on the inner surfaces of both side walls 6b of the cassette 6a, extending horizontally from the loading/unloading entrance 6c of the cassette 6a. The storage rails 6d are formed at the same height on both side walls 6b of the cassette 6a. The frame unit 11 can be stored in the cassette 6a by placing the ends of the frame 9 of the frame unit 11 on a pair of storage rails 6d at the same height. The frame unit 11 can then be loaded and unloaded through the loading/unloading entrance 6c.

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

Each of the pair of frame guide rails 8 has a substantially L-shaped cross section. The upper surface of the frame guide rail 8 serves as the support surface 8a on which the frame 9 of the frame unit 11 rests. Each frame guide rail 8 also has an upright portion 8b on the outside in the direction perpendicular to the extension direction (X-axis direction).

The frame guide rails 8 move toward and away from each other while remaining parallel in the Y-axis direction. The frame unit 11 is placed on the mounting surface 8a of the frame guide rails 8, and the pair of frame guide rails 8 are moved toward each other to sandwich the frame 9 between the upright portions 8b of the frame guide rails 8, thereby adjusting the position of the frame 9.

A carry-in/out unit 12 is provided on the top surface of the base 4 adjacent to the temporary placement unit 10. The carry-in/out unit 12 carries the frame unit 11 stored in the cassette 6a placed on the cassette stage 6 out of the cassette 6a. 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.

The loading/unloading 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.

For example, the main body 12a is brought close to the cassette 6a, and the frame unit 11 contained in the cassette 6a placed on the cassette stage 6 is grasped 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 remove the frame unit 11 from the cassette 6a and temporarily place it in the temporary placement unit 10.

Furthermore, for example, the frame 9 of the frame unit 11 temporarily placed on the temporary placement unit 10 can be gripped with the gripping portion 12b and the main body portion 12a moved toward the cassette 6a, thereby loading the frame unit 11 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 through which the frame unit 11 is loaded and unloaded matches the height of the loading/unloading unit 12.

A long opening 4a is formed in the X-axis direction (front-to-back direction, processing feed direction) 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 dust-proof and drip-proof cover 26 that covers the top of the X-axis movement mechanism are located within the opening 4a.

The X-axis movement mechanism is connected to the bottom of the X-axis movement table 16 and functions to move 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, which will be described later.

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 functions to hold the frame unit 11 while the workpiece 1 contained in the frame unit 11 is being machined.

A porous plate (not shown) is provided above the chuck table 20, and one end of a suction path (not shown) formed within 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.

A rotation drive mechanism (not shown) is provided below the chuck table 20 to rotate the chuck table 20 around a predetermined rotation axis. Furthermore, a clamp 24 that grips the frame 9 is 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.

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 the 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 the function of holding the frame unit 11 placed on the chuck table 20 and transporting it to the temporary placement unit 10.

As shown in Figure 4, the first transport unit 14 has a shaft 14a that protrudes upward from the top surface of the base 4 and is both movable and rotatable, 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 raises 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.

When the transport drive source 14d is operated to rotate the shaft 14a, the holder 14c can move between above the frame guide rail 8 of the temporary storage unit 10 and above the chuck table 20 positioned in the loading/unloading area. Furthermore, 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 rail 8 and above the chuck table 20.

When the first transport unit 14 transports the frame unit 11 from the temporary storage unit 10 to the chuck table 20, the X-axis moving table 16 is moved to position the chuck table 20 in the loading/unloading area. Then, the transport drive source 14d is activated to rotate the shaft 14a, moving the holding part 14c above the frame unit 11 temporarily stored on the temporary storage unit 10, and the shaft 14a is lowered to bring the holding part 14c into contact with the frame 9.

Next, the suction mechanism connected to the holder 14c is activated, sucking and holding the frame unit 11 (frame 9) from above. After that, the transport drive source 14d is again activated to raise the shaft 14a, lifting the frame unit 11, which is sucked and held by the holder 14c. The shaft 14a is then 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.

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

The processing device 2 includes a support structure 28 arranged across the opening 4a above the movement path of the X-axis moving table 16 from the loading/unloading area to the processing area. The support structure 28 is provided with an imaging unit 30 facing downward. The imaging unit 30 includes an imaging element such as a CMOS sensor or CCD sensor, and captures an image of the workpiece 1 included in the frame unit 11 from above, detecting the position and orientation of the planned division line 3 set on the surface 1a of the workpiece 1.

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 on the frame unit 11 held by the chuck table 20. Below, we will explain an example 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.

The processing unit 32 that cuts the workpiece 1 includes a cutting blade 34 with an annular cutting edge on its outer periphery, and a spindle 36 that is attached to the tip of the cutting blade 34 and runs along the Y-axis direction, serving as the axis of rotation for the cutting blade 34.

A rotary drive source such as a motor (not shown) is connected to the base end of the spindle 36, and the cutting blade 34 attached to one end of the spindle 36 rotates due to the force generated by this rotary drive source. The cutting blade 34 comprises 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.

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). Operating the processing feed unit and the indexing feed unit allows the chuck table 20, which holds the workpiece 1 by suction, and the processing unit 32 to move relative to each other.

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

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

The processing device 2 is equipped with 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 holding part provided below the tip of the arm.

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 is moved along the Y-axis direction to place the frame unit 11 on the spinner table of the cleaning unit 38. After that, the frame unit 11 is held by the spinner table and the workpiece 1 is cleaned.

When cleaning the workpiece 1 in the cleaning unit 38, a cleaning fluid (typically a mixed fluid of water and air) is sprayed toward the surface of the workpiece 1 while the spinner table is rotating. Then, by stopping the supply of cleaning fluid while continuing to rotate the spinner table, the frame unit 11 can be dried. After cleaning in the cleaning unit 38, the frame unit 11 is transferred from the cleaning unit 38 to the temporary storage unit 10 by the first transport unit 14.

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. The holder 14c then releases the suction-holding of the frame 9. The frame unit 11 is then temporarily placed on the temporary placement unit 10.

The frame unit 11, which has been returned to and temporarily placed in the temporary placement unit 10, is then loaded into the cassette 6a placed on the cassette stage 6 by the load/unload unit 12. As explained above, in the processing device 2, the frame unit 11 housed in the cassette 6a and loaded into the processing device 2 is then removed from the cassette 6a and transferred to the chuck table 20. The workpiece 1 is then processed in the processing unit 32, cleaned in the cleaning unit 38, and the frame unit 11 is then returned to the cassette 6a.

The processing device 2 is equipped with 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 composed of 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.

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 these 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 referencing the information sent from each component, and processes the workpiece 1 in a predetermined procedure.

Here, as shown in Figure 3, etc., the temporary placement unit 10 has a non-contact proximity sensor 8d for detecting whether the frame unit 11 (frame 9) is temporarily placed on the frame guide rail 8.

Figure 5(A) is a cross-sectional view showing a frame unit 11 temporarily placed on a temporary placement unit 10, and also includes a side view showing a frame guide rail 8 on one side of the temporary placement unit 10. Furthermore, Figure 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.

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 emits 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.

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

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 continuously sends electrical signals to the control unit 42 indicating the detection status of the frame unit 11. 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.

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

Furthermore, the proximity sensor 8d may malfunction during use and cease to function. 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 (frame 9) even when the frame unit 11 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 is unable to continue normal operation while processing the workpiece 1, resulting in it stopping.

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 or the like. However, because 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 decline in productivity.

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 caused by a malfunction of the proximity sensor 8d from occurring while the workpiece 1 is being processed. 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 while the workpiece 1 is being processed, and processing efficiency does not decrease.

The following continues the explanation of the processing device 2, focusing on the configuration related to monitoring the status of the proximity sensor 8d. Monitoring the status of the proximity sensor 8d is primarily achieved by the functions of the control unit 42. Figure 2 is a block diagram showing the configuration that contributes to the control unit 42's monitoring of the status of the proximity sensor 8d.

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 at the time the proximity sensor 8d detects the frame unit 11 (frame 9). 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, which functions as an elevation unit.

Figure 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, which functions as an elevation unit, to transport the frame unit 11 to the frame guide rail 8.

The distance determination unit 42b then determines the detection distance between the proximity sensor 8d and the frame unit 11 at the time the proximity sensor 8d detects the frame unit 11. In Figure 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.

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

The control unit 42 has a threshold memory unit 42a that stores a judgment threshold 8e set to the 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 judgment unit 42c that determines that the proximity sensor 8d is abnormal when the detection distance 8f identified by the distance identification unit 42b is shorter than the judgment threshold 8e stored in the threshold memory unit 42a.

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

For example, the detection distance 8f of an unused proximity sensor 8d is approximately 11 mm. In other words, 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 approximately 8 mm above the mounting surface 8a of the frame guide rail 8.

In this case, the determination threshold 8e, which is set to the distance detectable by the proximity sensor 8d, may be set to 7 mm, for example. That is, the determination unit 42c may determine that the proximity sensor 8d is abnormal when the detection distance 8f identified by the distance identification unit 42b is below 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 within 4 mm of the mounting surface 8a, the determination unit 42c determines that the proximity sensor 8d is abnormal.

If the proximity sensor 8d is determined to be abnormal, cleaning or replacing the proximity sensor 8d during the first maintenance work performed on the processing device 2 thereafter can prevent the processing device 2 from stopping due to a malfunction of the proximity sensor 8d while processing the workpiece 1. As a result, the operating time of the processing device 2 is not reduced, and the processing efficiency of the workpiece 1 in the processing device 2 is maintained.

The processing device 2 may also have an alarm unit (not shown) that issues various warnings to the user or administrator, and the control unit 42 may further include an alarm unit 42d that causes the alarm unit to issue a warning when the determination unit 42c determines that the proximity sensor 8d is abnormal.

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

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 an alarm unit. Alternatively, the warning unit 42d turns on an alarm lamp functioning as an alarm unit to indicate the abnormality. Alternatively, the warning unit 42d causes a speaker functioning as an alarm unit to emit an alarm sound.

When a user or manager of the processing device 2 receives a warning from the alarm unit, they can prepare to replace or clean the proximity sensor 8d the next time maintenance is performed on the processing device 2. By taking the specified measures during maintenance, it is possible to prevent the processing device 2 from shutting down due to a malfunction of the proximity sensor 8d.

Finally, we will summarize the steps of the anomaly detection method for determining whether or not there is an abnormality in the proximity sensor 8d in the processing device 2. Figure 6 is a flowchart showing the flow of each step of the anomaly detection method for determining whether or not there is an abnormality in the proximity sensor 8d in the processing device 2.

First, a frame holding step S10 is performed in which the frame 9 is held by the transport unit (first transport 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 transport 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 transport unit 14.

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 activated 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 caused to perform a detection operation for the frame 9, and a detection distance determination 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 determined.

Figure 5 (B) is a cross-sectional view that schematically illustrates the lowering step S20 and the detection distance determination step S30. For example, the frame unit 11 is lowered from above the frame guide rail 8 at a speed of approximately 0.5 mm per second while the proximity sensor 8d performs a detection operation. 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 determined.

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 of frame 9 when the proximity sensor 8d detected frame 9, which was identified in the detection distance determination step S30. If the distance from the proximity sensor 8d of 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 of frame 9 is equal to or greater than the determination threshold, it is determined that there is no abnormality in the proximity sensor 8d.

If it is determined in determination step S40 that there is an abnormality in the proximity sensor 8d, a warning step S50 may be performed in which the determination result is reported by a notification unit provided in the processing device 2. In this case, the user or manager of the processing device 2 will be informed of the abnormality in the proximity sensor 8d, allowing them to consider countermeasures and take action before the proximity sensor 8d malfunctions.

The present invention is not limited to the above embodiment and can be implemented with various modifications. For example, in the above embodiment, the frame unit 11 held by the holding portion 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.

In other words, in a processing device and proximity sensor anomaly detection method according to one aspect of the present invention, the frame unit 11 may be held by the second transport unit 40 instead of the first transport unit 14 as the transport unit, and the detection distance of the proximity sensor 8d may be determined. In other words, there are no restrictions on the transport unit that holds the frame unit 11.

In addition, in the above embodiment, the frame unit 11 is lowered onto the frame guide rail 8 from above to determine the detection distance at which the proximity sensor 8d detects the frame 9. However, this is not a limitation of one aspect of the present invention. For example, when the frame unit 11 placed on the frame guide rail 8 is grasped and raised by the holding portion 14c of the first transport unit 14, the distance at which the proximity sensor 8d no longer detects the frame 9 may be determined as the detection distance.

Furthermore, in the above embodiment, 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 processing device 2 is stopped for maintenance work. However, one aspect of the present invention is not limited to this.

In other words, measures such as replacing the proximity sensor 8d do not need to be taken 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 abnormality and continue to use the proximity sensor 8d for as long as it determines that the proximity sensor 8d is suitable for use.

In addition, 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 individually for each proximity sensor 8d.

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 then housed in a cassette 6a and transported, and the workpiece 1 contained in the frame unit 11 is processed by the processing unit 32. However, one aspect of the present invention is not limited to this.

After processing of the workpiece 1 is complete, the frame unit 11 is stored in the cassette 6a and removed from the processing device 2. The processed workpiece 1 is then peeled off from the tape 7, and the frame unit 11 is disassembled. The frame 9 contained 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 required cleaning.

However, as the frame 9 is repeatedly used, small scratches may form on its surface, or slight twists or distortions may occur. 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 all of 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 way.

As a result, the detection distance of the proximity sensor 8d varies depending on the state of the frame 9 that is the detection target. Therefore, in order to more stably and accurately determine whether the proximity sensor 8d is abnormal, in one aspect of the present invention, a determination frame may be prepared and used solely for the purpose of determining whether the proximity sensor 8d is abnormal.

In this case, the determination frame may be housed in a cassette 6a and transported to the processing device 2. Alternatively, the determination frame may be stored near the processing device 2, and the 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.

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

When using the judgment frame to determine whether or not there is an abnormality in the proximity sensor 8d, the detection distance of the proximity sensor 8d does not fluctuate depending on the state of the frame 9, and the judgment result of the judgment unit 42c of the control unit 42 is not affected by the state of the frame 9. This increases the reliability of the judgment result of the judgment unit 42c, and proximity sensors 8d that are determined to be normal can be reliably used and continue to be used. This also allows for a more precise plan for cleaning and replacing the proximity sensor 8d.

In addition, the structures, methods, etc. related to the above embodiments can be modified as appropriate without departing from the scope of the present invention.

REFERENCE SIGNS LIST 1 workpiece 1a front surface 1b back surface 3 planned division line 5 device 7 tape 9 frame 9a opening 11 frame unit 2 processing device 4 base 4a, 4b opening 6 cassette stage 6a cassette 6b side wall 6c carry-in/out entrance 6d storage rail 8 frame guide rail 8a placement surface 8b standing portion 8c through hole 8d proximity sensor 8e judgment threshold 8f detection distance 10 temporary placement unit 12 carry-in/out unit 12a main body 12b gripping portion 14 first transport unit 14a shaft portion 14b arm portion 14c holding portion 14d transport drive source 16 X-axis moving table 18 table base 20 chuck table 22 holding surface 24 clamp 26 dustproof/waterproof 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 value storage unit 42b: Distance determination unit 42c: Determination unit 42d: Warning unit

Claims (4)

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. 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. The processing device described in 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. 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.