JP2009255242A - Suction device, retaining table, conveying device, workpiece machining device, and method for machining workpiece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid a reduction in machining quality and a damage to a workpiece even if a suction force of a suction device sucking the workpiece in a machining device is decreased for any reason. <P>SOLUTION: A value of vacuum applied from a suction force generating means 101 to a suction surface 100a sucking the workpiece is measured by a pressure gauge 101c. The measured value is compared with a first threshold of the suction force, as a reference for determining whether the workpiece is actually sucked by the suction surface 100a, and a second threshold of the suction force, as a reference for determining whether the suction surface 100a and suction force generating means 101 are abnormal. Then, it is determined whether the workpiece is appropriately retained and in a state in which it is appropriately retained from a magnitude relation between the measured value and the first and second thresholds and the estimated content of a suction estimation section 50 estimating whether the workpiece is sucked by the suction surface 100a, based on status information of a suction section 100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a suction device that sucks a workpiece, a holding table having the suction device, a transport device, a workpiece machining device, and a workpiece machining method using the workpiece machining device.

  In a processing apparatus that processes various workpieces (workpieces), a suction device having a suction surface that communicates with a suction source is used as a means for holding the workpiece. This suction device is used for the purpose of sucking and holding a workpiece when processing the workpiece, or holding a workpiece to be transferred when the workpiece is transferred by a negative pressure acting on the suction surface. For example, in a cutting device that cuts a workpiece such as a semiconductor wafer, the workpiece to be cut is held by a chuck table. Usually, the chuck device employs the suction device, and suction that communicates with a suction source. The workpiece is held on the surface. In addition, the workpiece before and after the processing is transported to a predetermined position in the cutting device by the transport device, and the suction device is also adopted in this transport device (see, for example, Patent Document 1).

JP 2002-359111 A

  However, in the suction device configured to hold the workpiece by the negative pressure described above, some foreign matter may be mixed between the suction source and the suction surface, and in this case, the suction force on the suction surface is reduced. Become. If the suction force is reduced in this way, there may be a problem in processing such as a shift of the processing position in the chuck table that holds the workpiece to be processed. Moreover, in the conveyance apparatus which conveys a workpiece | work, the workpiece | work may fall and be damaged by the fall of the holding power of a workpiece | work. Furthermore, in other processing apparatuses equipped with the same suction device, the processing quality may be deteriorated or the workpiece may be damaged.

  The present invention has been made in view of these facts, and its main technical problem is that even if the suction force of the suction device that sucks the workpiece in the processing device is reduced for some reason, the processing quality is lowered. It is to avoid causing the work or the work to be damaged.

  The first invention includes a suction portion having a suction surface for sucking a workpiece, a suction force generation means for generating a suction force acting on the suction surface, and a control means for controlling the suction portion and the suction force generation means. With respect to the suction device, the suction force generating means includes a suction mechanism, a communication path for communicating the suction mechanism and the suction surface, and a pressure gauge disposed in the communication path, and the control means includes status information of the suction section. A suction estimation unit that estimates whether or not the workpiece is attracted to the suction surface, and a first threshold value of the suction force that serves as a reference for determining whether or not the workpiece is actually attracted to the suction surface. A first threshold storage unit and a second threshold storage unit that stores a second threshold value of suction force that serves as a reference for determining whether or not the suction surface and the suction force generation unit are abnormal. The suction estimation unit estimates that the workpiece is not attracted to the suction surface. In addition, when the measured value in the pressure gauge falls below the first threshold, an abnormality is detected that the workpiece is adsorbed on the adsorption surface, and the adsorption estimation unit estimates that the workpiece is not adsorbed on the adsorption surface. If the measured value in the pressure gauge is greater than or equal to the first threshold value and less than or equal to the second threshold value, it is determined that there is an abnormality in either the suction surface or the suction force generation means although the workpiece is not sucked on the suction surface If the suction estimation unit estimates that the workpiece is not attracted to the suction surface and the measured value on the pressure gauge exceeds the second threshold, it is determined that there is no abnormality. Is adsorbed and the measured value in the pressure gauge falls below the first threshold, it is determined that there is no abnormality.

  A second invention relates to a holding table that is disposed in a processing apparatus and holds a workpiece to be processed. The holding table includes the suction device described above, and holds the workpiece on the suction surface. In this holding table, it is desirable that the second threshold value be −35 kPa to −45 kPa.

  3rd invention is related with the conveying apparatus which conveys the workpiece | work of process object, is equipped with said adsorption | suction apparatus, hold | maintains and conveys a workpiece | work in the said adsorption surface.

  The fourth invention relates to a processing apparatus comprising at least a holding table that holds a workpiece to be processed, a processing means that processes the workpiece held on the holding table, and a transport device that transports the work. The apparatus includes the above-described suction device and holds the workpiece on the suction surface.

  According to a fifth aspect of the present invention, there is provided a workpiece processing method for processing a workpiece held on a holding table by the processing means using the processing apparatus, and the suction estimation unit estimates that the workpiece is not held on the suction surface of the holding table. In the case where the suction force is applied to the suction surface and the measured value of the pressure gauge falls below the first threshold value, the control means detects that the workpiece is held on the suction surface. If the pressure gauge measurement value is greater than or equal to the first threshold and less than or equal to the second threshold, the control means detects that the new workpiece is not placed on the adsorption surface. The workpiece is not held, but it is judged that there is an abnormality in either the suction surface or the suction force generation means, and this is notified, and if the measured value of the pressure gauge exceeds the second threshold value, control is performed. Means that the suction force is normal and new A determination step for allowing the workpiece to be attracted to the suction surface, a transport step for transporting the workpiece to the suction surface of the holding table by the transport device when the suction force is determined to be normal in the determination step, and a holding table And a processing step of processing the work held on the suction surface by the processing means.

  The suction device according to the present invention includes a suction estimation unit that estimates whether or not a workpiece is sucked on the suction surface, and serves as a reference for determining whether or not the workpiece is actually sucked on the suction surface. The value of the suction force is the first threshold, the value of the suction force that serves as a reference when determining whether there is an abnormality in the suction surface and the suction force generation means is the second threshold, Since the control means determines the magnitude relationship between the first threshold value and the second threshold value, according to the magnitude relationship, whether there is actually a work on the suction surface and whether the suction force on the suction surface has decreased Can be determined at a time.

  The holding table according to the present invention is provided with the above-described suction device, so that it is possible to grasp whether the workpiece to be processed is held with sufficient suction force, and to handle when the suction force is not normal. It can be performed with high accuracy, and it can be grasped whether or not the workpiece is already held. In addition, by setting the second threshold value to −35 kPa to −45 kPa, it is possible to appropriately determine whether or not there is insufficient suction force due to clogging of the communication path.

  The conveyance device according to the present invention includes the above-described suction device to prevent the workpiece from falling and being damaged by grasping whether the workpiece to be processed is held with sufficient suction force. It is possible to grasp whether or not the workpiece is already held.

  A workpiece processing apparatus according to the present invention includes a holding table that holds a workpiece, a processing unit that processes the workpiece held on the holding table, and a conveyance device that conveys the workpiece, and the suction device is attached to the holding table or the conveyance device. It is possible to prevent high-precision machining by preventing machining deviation of workpieces held on the holding table and collision between workpieces, and dropping of workpieces and collision between workpieces during conveyance of workpieces before and after machining. Can be prevented from being damaged.

  The workpiece machining method according to the present invention uses the workpiece machining apparatus described above, and when it is considered that the workpiece is originally not attracted to the suction surface of the holding table, By controlling so that the next workpiece is not attracted, it is possible to avoid a new workpiece from being placed while the workpiece is held on the holding table, thereby avoiding a collision between the workpieces. In addition, when it is considered that the workpiece is not attracted to the suction surface of the holding table, if the suction force is not sufficient, a notification is given to that effect, and if the suction force is normal, a new workpiece is When a new workpiece is allowed to be sucked, the new workpiece is transferred to the holding table by the transfer device, and the workpiece is processed. The workpiece can be machined, and machining deviation can be prevented and high-precision machining can be performed.

  A cutting device 1 shown in FIG. 1 is a kind of a device for processing a workpiece such as a semiconductor wafer, a holding table 2 that holds the workpiece, and a cutting unit that is a processing unit that cuts the workpiece held on the holding table 2. 3 is provided. While the holding table 2 is movable in the X-axis direction, the cutting means 3 is movable in the Y-axis direction and the Z-axis direction. The holding table 2 includes a suction unit 20 that sucks a workpiece, and a suction force generation unit 101 shown in FIG. 2 provided inside the apparatus. The cutting means 3 is configured such that a cutting blade 31 is attached to the tip of the rotating shaft 30 and the cutting blade 31 also rotates as the rotating shaft 30 rotates. Above the movement path of the holding table 2, an alignment unit 4 is provided that images and detects the position to be cut of the workpiece by the imaging unit 40 and performs alignment with the cutting blade 31. The holding table 2, the cutting means 3 and the alignment means 4 are controlled by a control means 5 inside the apparatus having a CPU, a memory and the like. Further, status information including the position on the coordinates of the part such as the suction unit 20 and the operation state is also recognized by the control means 5.

  In the cutting apparatus 1, the work W to be cut is attached to the tape T, and the work W is integrated with the frame F via the tape T by attaching the tape T to the ring-shaped frame F. Is supported. And the workpiece | work W is accommodated in the cassette C in the state. In the vicinity of the cassette C, there is provided a placement area 60 for placing and aligning the workpiece W. In the placement area 60, the workpiece before cutting is taken out from the cassette C, and the workpiece after cutting is placed in the cassette. A loading / unloading means 6 accommodated in C is disposed.

  Between the placement area 60 and the holding table 2, a first transfer device 7 that holds and transfers the workpiece W is disposed. The first transport device 7 includes a suction portion 70 that sucks a workpiece, an arm portion 71 that can swing and move up and down, and a suction force generation means 101 shown in FIG. The work can be transported between the placing area 60 and the holding table 2 by the arm part 71 turning and moving up and down while the work is held in the part 70.

  A cleaning means 8 for cleaning the workpiece after cutting is disposed in the vicinity of the holding table 2, and a second portion for conveying the work between the holding table 2 and the cleaning means 8 is disposed above the cleaning means 8. A transport device 9 is provided. The second transport device 9 includes a suction portion 90 that sucks a workpiece, an arm portion 91 that can move horizontally and move up and down, and a suction force generation unit (not shown) provided inside the device. The arm 91 moves horizontally and moves up and down while holding the workpiece, so that the workpiece can be transferred between the holding table 2 and the cleaning means 8. The first transport device 7 and the second transport device 9 are controlled by the control unit 5 and status information including the position and operation state of the suction units 70 and 90 on the coordinates is always recognized by the control unit 5. .

  The holding table 2, the first transport unit 7, and the second transport unit 9 have a suction device 10 shown in FIG. 2. That is, the suction device 10 is configured to be applicable to any of the holding table 2, the first transport unit 7, and the second transport unit 9, and has a suction unit 100 having a suction surface 100 a that sucks a workpiece. And a suction force generating means 101 for generating a suction force acting on the suction surface 100a, and a control means 5 for controlling the suction portion 100 and the suction force generating means 101.

  The suction force generating means 101 generates a negative pressure and measures a suction mechanism 101a that is a suction source, a communication path 101b that connects the suction mechanism 101a and the suction surface 100a, and a negative pressure connected to the communication path 101b. Pressure gauge 101c. The control means 5 is electrically connected to the pressure gauge 101c, and the control means 5 can read the measurement value of the pressure gauge 101c and perform processing according to the value. In FIG. 2, the suction surface 100 a faces upward, but in the first transport device 7 and the second transport device 9, the suction surface 100 a faces downward.

  The control means 5 recognizes the status information of the suction unit 100 provided in the holding table 2, the first transport device 7 and the second transport device 9, and sucks the work in each suction unit 100 based on the status. An adsorption estimation unit 50 that estimates whether or not the operation is performed is provided. The suction estimation unit 50 is based on, for example, the position in the X-axis direction of the holding table 2 in FIG. 1, the position of the suction unit 70 of the first transport device 7 or the suction unit 90 of the second transport device 9, and the like. It is determined whether or not it is estimated that the suction unit 100 is holding a workpiece. For example, when the holding table 2 is moving in the + X direction even slightly from the position (home position) farthest from the cutting means 3 as shown in FIG. On the other hand, when the holding table 2 is at the home position, it is estimated whether or not the workpiece is attracted by the combined information with the statuses of the first transfer device 7 and the second transfer device 9. For example, when the holding table 2 is at the home position and the suction unit 70 of the first transfer device 7 is in the process of returning to the placement area 60 without holding anything, and after returning, the workpiece is held on the holding table 2. Presumed to hold. On the other hand, when the holding table 2 is at the home position and the first transfer device 7 has never moved, it is estimated that the workpiece is not held on the holding table 2.

  The control means 5 includes a first threshold value storage unit 51 that stores a first threshold value of a suction force (negative pressure) that is a reference for determining whether or not a workpiece is actually sucked on the suction surface 100a; A second threshold value storage unit 52 that stores a second threshold value of the suction force that serves as a reference for determining whether or not the suction surface 100a and the suction force generation means 101 are abnormal. These are constituted by a storage element such as a memory, and the pressure values stored in the first threshold value storage unit 51 and the second threshold value storage unit 52 are input units provided on the front side of the cutting apparatus 1 in FIG. 53 can be input. In the control means 5, the holding table 2, the first transfer device 7, and the first transfer device are calculated based on the estimation in the adsorption estimation unit 50 and the comparison result between the measurement value read from the pressure gauge 101 c and the first threshold value and the second threshold value. It is possible to determine whether there is an abnormality in the suction surface 100a and the suction force generation means 101 constituting the second transport device 9, and whether or not a workpiece is held on the suction surface 100a. As shown in FIG. 3, the first threshold value is smaller than the second threshold value. For example, the first threshold value is −55 to −65 [kPa], and the second threshold value is Is −35 to −45 [kPa].

  As shown in FIG. 3, the measured value of the negative pressure in the pressure gauge 101c is in a state (1) that is below the first threshold, and in a state (2) that is not less than the first threshold and not more than the second threshold. ), And can be roughly classified into a state (3) which is a state exceeding the second threshold. If the workpiece is actually sucked on the suction surface 100a, the negative pressure value decreases (the absolute value increases), and the negative pressure value increases (the absolute value decreases) when the workpiece is not sucked. In the state (3), the control means 5 can determine that the workpiece is sucked on the suction surface 100a. In state (2), the workpiece is not held on the suction surface 100a, but the control means 5 can determine that the negative pressure value is lower than that in the normal state. In the state (1), the control means 5 can determine that the workpiece is not held on the suction surface 100a and the negative pressure value at that time is also normal.

  Further, the combination of these three states and the content estimated by the suction estimation unit 50 determines whether there is an abnormality in the suction surface 100a and the suction force generation means 101, and whether or not the workpiece is actually held on the suction surface 100a. can do.

表１からは、保持テーブル２が１２インチの場合も８インチの場合も、一部の例外を除き負圧の計測値は−３５［ｋＰａ］を上回り、平均値はそれぞれ−３１．０［ｋＰａ］、−３１．９［ｋＰａ］であることがわかった。第二の閾値の値を低くしすぎると、連通路１０１ｂが詰まる等して吸引力が低下しても異常なしと誤認してしまうおそれがあり、逆に、第二の閾値を高くしすぎると、吸引力が正常でも異常と誤認してしまうおそれがある。したがって、上記実験結果と、実験環境は切削時に近い環境ではあるが切削時よりも連通路１０１ｂ内に水分が多く残っているであろうこと（実際の切削時には吸着面１００ａに直接水がかかることはないため）とを踏まえ、第二の閾値は、−３５〜−４５［ｋＰａ］の範囲、例えば−４０［ｋＰａ］に設定することが望ましいと考えられる。 In the first threshold value storage unit 51 and the second threshold value storage unit 52, values can be individually set for the holding table 2, the first transfer device 7, and the second transfer device 9, respectively. You can also set a value. For example, it is known from experience that the value of the negative pressure when the workpiece W is normally held on the suction surface 100a of the holding table 2 is less than −60 [kPa]. However, if the value of the first threshold is too low, there is a risk that it will be mistaken as normal even if it is not normally adsorbed, and conversely, if the first threshold is too high, Actually, even if it is normally adsorbed, it may be mistaken for an abnormality. Therefore, it is desirable to set the first threshold value in a range of −55 to −65 [kPa], for example, −60 [kPa]. On the other hand, since the value of the second threshold value was unknown, an optimum value range was obtained by performing an experiment. In such an experiment, in order to make the environment close to the time of cutting without holding the workpiece in the suction portion 100a of the holding table 2, water corresponding to the cutting water is first discharged to the holding table 2, and then the pressure gauge The negative pressure at 101c was measured. Immediately after the water was discharged, the negative pressure suddenly decreased in the negative direction, so that the negative pressure gradually increased and stabilized to a certain degree, and then the negative pressure was continuously measured four times using the pressure gauge 101c. As the holding table 2, the suction surface is a porous type and two general types of 8 inch size and 12 inch size are used, and water is discharged to the holding table 2 to perform continuous measurement four times as one set. Three sets of measurements were performed for each type of holding table. The experimental results are shown in Table 1 below.
(Table 1)

From Table 1, it can be seen that, with some exceptions, the measured value of negative pressure exceeds -35 [kPa], and the average value is -31.0 [kPa], regardless of whether the holding table 2 is 12 inches or 8 inches. It was found to be -31.9 [kPa]. If the value of the second threshold value is too low, there is a risk that the communication path 101b may be clogged, and even if the suction force decreases, it may be mistaken for no abnormality. Conversely, if the second threshold value is too high, Even if the suction force is normal, it may be mistaken for an abnormality. Therefore, although the above experimental results and the experimental environment are close to the time of cutting, more water will remain in the communication path 101b than at the time of cutting. Therefore, it is considered desirable to set the second threshold value within a range of −35 to −45 [kPa], for example, −40 [kPa].

  As shown in FIG. 3, before the suction is turned on, that is, when the suction force from the suction mechanism 101a is not applied to the suction surface 100a, the measured value of the negative pressure in the pressure gauge 101c exceeds the second threshold value. ing. When the suction is turned on, the suction estimation unit 50 shown in FIG. 2 estimates that the workpiece is not attracted to the suction surface 100a and that the workpiece is not attracted to the suction surface 100a. In some cases, the control means 5 determines as follows.

  In the case where the suction estimation unit 50 estimates that the workpiece is not sucked on the suction surface 100a, if the measured value of the negative pressure exceeds the second threshold as in the state (1), the workpiece is actually moved. The control means 5 determines that the suction is not performed and the negative pressure value is normal.

  When the suction estimation unit 50 estimates that the workpiece is not sucked on the suction surface 100a, and the negative pressure measurement value is not less than the first threshold and not more than the second threshold as in the state (2), Although the workpiece is not actually attracted, the control means 5 determines that the negative pressure value is lower than the normal value.

  When the suction estimation unit 50 estimates that the workpiece is not sucked on the suction surface 100a, the workpiece is sucked when the measured value of the negative pressure falls below the first threshold as in the state (3). The control means 5 determines that the workpiece is actually sucked although it should not be. The quality of the negative pressure at this time is unknown.

  In the case where the suction estimation unit 50 estimates that the workpiece is sucked on the suction surface 100a, the workpiece is sucked if the measured value of the negative pressure exceeds the second threshold as in the state (1). Although it should be, the control means 5 determines that the workpiece is not actually attracted.

  When the suction estimation unit 50 estimates that the workpiece is sucked on the suction surface 100a, and the negative pressure measurement value is not less than the first threshold and not more than the second threshold as in the state (2), Although the workpiece should be sucked, the control means 5 determines that the workpiece is not actually sucked and the negative pressure value is lower than the normal value.

  If it is estimated that the workpiece is sucked on the suction surface 100a, and the suction estimation unit 50 is in the case where the measured value of the negative pressure falls below the first threshold as in the state (3), the workpiece is actually The control means 5 determines that the adsorbed is adsorbed. The quality of the negative pressure at this time is unknown.

  When the workpiece W is cut by the cutting apparatus 1 shown in FIG. 1, the workpiece W supported integrally with the frame F via the tape T is accommodated in the cassette C. In the following, the workpiece W supported integrally with the frame F via the tape T is simply referred to as a workpiece W. The workpiece W is not particularly limited. For example, a wafer such as a semiconductor wafer, an adhesive member such as DAF (Die Attach Film) provided on the back surface of the wafer for chip mounting, a semiconductor product package, a glass-based or silicon-based substrate, Examples include various processing materials that require micron-order processing accuracy.

  The work W is placed on the placement area 60 by the carry-in / out means 6 holding the frame F and pulling it out to the placement area 60. Then, the workpiece W is adsorbed by the adsorbing portion 70 constituting the first transport device 7, and the arm portion 71 turns to move the workpiece W to the position just above the holding table 2, where the arm portion 71 is lowered and adsorbed. By releasing the suction in the part 70, the part 70 is placed on the suction part 20 of the holding table 2. Before the workpiece W is placed on the holding table 2, it can be determined in advance whether or not the workpiece can be properly held in the holding table 2 as shown below.

  Specifically, before the workpiece W is transferred to the holding table 2, that is, in a state where the holding table 2 holds nothing, as shown in the flowchart of FIG. 4, the suction mechanism 101a shown in FIG. A negative pressure is applied to the suction surface 100a of the holding table 2 by applying a suction force (step S1). And the control means 5 reads the measured value of the negative pressure of the pressure gauge 101c, and judges whether the value belongs to any state (1), (2), or (3) shown in FIG. 3 (step S2). Judgment process).

  Before the workpiece W is held on the holding table 2, the suction estimation unit 50 estimates that the suction surface 100a is not sucking the workpiece, so the measurement value read in step S2 belongs to the range of (1). In this case, the control means 5 determines that the suction force by the suction mechanism 101a is not normal and the suction force by the suction mechanism 101a is normal, and the new work W is attracted to the suction surface 100a of the holding table 2. Is allowed. Then, the work W to be cut is transported and placed on the holding table 2 by the first transport device 7 so that the work W is sucked and held on the suction surface 100a of the holding table 2 (step S3, transport process). ). Next, after the holding table 2 holding the workpiece W is moved in the X-axis direction in FIG. 1 and the position to be cut is detected by the alignment means 4 and aligned with the cutting blade 31 in the Y-axis direction, As the holding table 2 moves in the same direction, the cutting means 3 descends while the cutting blade 31 rotates at a high speed, and the cutting blade 31 cuts into the workpiece W to perform cutting (step S4, processing step). During cutting, since the holding table 2 does not return to the home position and the suction estimation unit 50 estimates that the workpiece is held on the holding table 2, the control means 5 also measures the pressure gauge 101c during cutting. If the measured value falls within the range of (1) above, it can be determined that the adsorption is performed normally.

  If the measurement value read in step S2 belongs to the range (2), another work is not held on the holding table 2, but the suction force is not sufficient, so the work W is transported and held as it is. When cutting is performed, the cutting position may be shifted during cutting, and the processing quality may be deteriorated. Therefore, in order to avoid such a situation, the operator is notified that there is an abnormality in the suction force generation means 101 including the suction surface 100a and the communication path 101b by ringing a notification means such as a buzzer (step S5). . Then, the operator or engineer investigates the cause of the decrease in the attractive force and removes the cause (step S6). Next, the measured value of the negative pressure of the pressure gauge 101c is read again by the control means 5 (step S2). On the other hand, if the measured value remains in the range of (2), an abnormality is notified (step S5), and the cause is solved and removed again (step S6).

  If the measurement value read in step S2 belongs to the range of (3), it is considered that another work is already held in the holding table 2, so the control means 5 detects the abnormality and tries to process it. The work is transported to the holding table 2 by the first transport device 7 under the control of the control means 5, and the work that should not be held is removed from the holding table 2 (step S7). And if the control means 5 reads the measured value of the negative pressure of the pressure gauge 101c again and the value changes into the value of the range of (1), it will progress to step S3 and subsequent steps.

  When the cutting process performed in step S4 is completed, the holding table 2 returns to the home position, and the workpiece W is transported to the cleaning means 8 by the second transport device 9, and cleaning and drying are performed. On the other hand, before the workpiece to be cut next is conveyed to the holding table 2 by the first conveying device 7, the processing of steps S1 and S2 in FIG. 4 is performed each time. , 6 and 7 are performed. As described above, when another workpiece is held on the holding table 2 by determining whether another workpiece is held on the holding table 2 and whether the suction force is normal before cutting the workpiece. , It is possible to avoid workpieces colliding with each other by conveying new workpieces. If there is an abnormality in the adsorption force, the cause can be solved before cutting to prevent the cutting quality from deteriorating. can do.

  In the above example, it is determined whether or not there is an abnormality in the procedure shown in FIG. 4 before holding the workpiece in the holding table 2, but this processing is performed in the first transfer device 7 and the second transfer device. 9 can also be applied to avoid the occurrence of suction abnormality before suction for carrying the workpiece.

  For example, in step S3 shown in FIG. 4, the first transport device 7 sucks the workpiece before cutting and transports it to the holding table 2, but before the workpiece is sucked, the procedure shown in FIG. It is checked whether or not the suction surface 100a and the suction force generating means 101 constituting the one transport device 7 are normal. First, before the suction surface 100a of the first transport device 7 sucks the work placed on the placement region 60, negative pressure is applied to the suction surface 100a from the suction mechanism 101a (step S11), and the pressure gauge The control means 5 reads the negative pressure value from 101c, and determines whether the value belongs to (1), (2), or (3) shown in FIG. 3 (step S12).

  Before the workpiece W is held on the suction surface 100a of the first transfer device 7, the suction estimation unit 50 estimates that the workpiece is not sucked on the suction surface 100a from the status information of the first transfer device 7. Therefore, if the measured value read in step S12 belongs to the range (1), the control means that the suction force by the suction mechanism 101a is normal rather than the state in which another work is held in the first transport device 7. 5 allows the new workpiece W to be attracted to the suction surface 100a of the first transfer device 7. Then, the work to be conveyed is sucked (step S13) and conveyed (step S14). During the conveyance, the measured value of the pressure gauge 101c is read, and when the measured value belongs to the range (1), it can be determined that the adsorption is performed normally.

  If the measured value read in step S12 belongs to the range (2), another workpiece is not held by the first transport device 7, but the suction force is not sufficient, so the workpiece W is left as it is. If it is adsorbed and conveyed, the workpiece W may fall and be damaged during the conveyance. Therefore, the operator is notified that there is an abnormality in the suction surface 100a of the first transport device 7 and the suction force generation means 101 by sounding a notification means such as a buzzer (step S15). Then, the operator or engineer investigates the cause of the decrease in the suction force and removes the cause (step S16). Then, the measured value of the negative pressure of the pressure gauge 101c is read again by the control means 5, and if it is a normal value, that is, a value in the range of (1), the process proceeds to step S13 and thereafter. On the other hand, if the measured value remains in the range of (2), an abnormality is notified (step S15), and the cause is clarified and removed again (step S16).

  If the measured value read in step S12 belongs to the range (3), it is considered that another work is already held on the suction surface 100a of the first transfer device 7, and the control means 5 indicates that abnormality. Detecting and controlling the work to be processed under the control of the control means 5 to be held on the suction surface 100a of the first transport device 7 and removing the work from the first transport device 7 (Step S17). And if the control means 5 reads the measured value of the negative pressure of the pressure gauge 101c again and the value changes into the value of the range of (1), it will progress to step S13 and subsequent steps. The same processing is performed when the subsequent workpieces are transported.

  As described above, before the workpiece is transferred, it is determined whether another workpiece is held in the first transfer device 7 and whether the suction force is normal. When the workpiece is held, it is possible to avoid the workpieces from colliding with each other when the workpiece is newly conveyed. When there is an abnormality in the suction force, the workpiece can be prevented from being damaged by dropping. In the second transport device 9 as well, when the workpiece is transported between the holding table 2 and the cleaning means 8, it is possible to avoid the workpieces from colliding with each other while trying to newly transport the workpiece, and the suction force. If there is an abnormality, it is possible to prevent damage due to falling of the workpiece.

  In the above example, the case where the present invention is applied to the holding table 2, the first transfer device 7, and the second transfer device 9 in the cutting device 1 has been described. However, the applied device is another processing device. For example, a grinding device or a polishing device may be used. In a grinding apparatus or a polishing apparatus, a process corresponding to a measured value of the suction force can be performed in a holding table that holds a workpiece to be ground or a polishing object or a transfer apparatus that transfers a workpiece to be processed in the apparatus. In addition, the present invention can be applied to a transport device that is used separately from the processing device.

It is a perspective view which shows an example of a processing apparatus. It is a schematic diagram which shows the structure of an adsorption | suction apparatus. It is a graph which shows the judgment content in the relationship with a 1st threshold value and a 2nd threshold value. It is a flowchart which shows the example of a process with a holding | maintenance table. It is a flowchart which shows the example of the process in a conveying apparatus.

Explanation of symbols

1: Cutting device 2: Holding table 20: Suction unit 3: Cutting unit 30: Rotating shaft 31: Cutting blade 4: Alignment unit 40: Imaging unit 5: Control unit 50: Suction estimation unit 51: First threshold storage unit 52 : Second threshold storage unit 53: input unit 6: carry-in / out means 60: placement area 7: first transport device 70: suction unit 71: arm unit 8: cleaning unit 9: second transport device 90: suction Unit 91: Arm unit 10: Suction device 100: Suction unit 100a: Suction surface 101: Suction force generating means 101a: Suction mechanism 101b: Communication path 101c: Pressure gauge

Claims (6)

An adsorption device comprising an adsorption part having an adsorption surface for adsorbing a workpiece, an attractive force generation means for generating an attractive force acting on the adsorption surface, and a control means for controlling the adsorption part and the attractive force generation means There,
The suction force generating means includes a suction mechanism, a communication path that communicates the suction mechanism and the suction surface, and a pressure gauge disposed in the communication path,
The control means includes a suction estimation unit that estimates whether or not a workpiece is attracted to the suction surface based on the status information of the suction portion, and a determination of whether or not the workpiece is actually attracted to the suction surface. A first threshold value storage unit for storing a first threshold value of a suction force as a reference, and a second threshold value of a suction force as a reference for determining whether or not there is an abnormality in the suction surface and the suction force generation means And a second threshold storage unit for storing
The control means includes
When the adsorption estimation unit estimates that the workpiece is not adsorbed on the adsorption surface, and the measured value of the pressure gauge falls below the first threshold, the workpiece is adsorbed on the adsorption surface. And detect anomalies with
When the adsorption estimation unit estimates that the workpiece is not adsorbed on the adsorption surface, and the measured value in the pressure gauge is not less than the first threshold and not more than the second threshold, the workpiece is placed on the adsorption surface. Is not adsorbed, but it is determined that either the adsorbing surface or the suction force generating means is abnormal,
When the adsorption estimation unit estimates that the workpiece is not adsorbed on the adsorption surface, and the measurement value in the pressure gauge exceeds the second threshold, it is determined that there is no abnormality,
An adsorption device that determines that there is no abnormality when the adsorption estimation unit estimates that a workpiece is adsorbed on the adsorption surface, and the measurement value of the pressure gauge falls below the first threshold value. A holding table that is disposed in a processing apparatus and holds a workpiece to be processed,
A holding table comprising the suction device according to claim 1 and holding the workpiece on the suction surface.   The holding table according to claim 2, wherein the second threshold value is −35 kPa to −45 kPa. A conveying device for conveying a workpiece to be processed,
A transporting device comprising the suction device according to claim 1 and holding and transporting the workpiece on the suction surface. A processing device comprising at least a holding table for holding a workpiece to be processed, a processing means for processing the workpiece held on the holding table, and a transport device for transferring the workpiece,
The holding table or the transfer device includes the suction device according to claim 1, and is a processing device that holds the workpiece on the suction surface. A workpiece machining method for machining a workpiece held on the holding table by the machining means using the machining apparatus according to claim 5,
When the suction estimation unit estimates that the workpiece is not held on the suction surface of the holding table, the suction force by the suction mechanism is applied to the suction surface, and the measured value of the pressure gauge is the first value. The control means detects an abnormality that the workpiece is held on the suction surface and regulates the new workpiece not to be placed on the suction surface, and the pressure gauge When the measured value is not less than the first threshold value and not more than the second threshold value, the control means does not hold the work on the suction surface, but the suction surface or the suction force generating means. If any of the pressure gauges exceeds the second threshold, the control means determines that the suction force is normal. A determination step for allowing a new workpiece to be attracted to the attracting surface;
When it is determined that the suction force is normal in the determination step, a transfer step of transferring the workpiece to the suction surface of the holding table by the transfer device;
A processing step of processing the work held on the suction surface of the holding table by the processing means;
Workpiece processing method including

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