JP2019220634A - Conveying method for work piece - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate cracks or the like in a workpiece when a workpiece held on a table is delivered to a transport member and transported, even if foreign matter exists between the suction surface of the transport member and the workpiece. Do not let it. SOLUTION: A step of sucking the other surface (back surface) Wb of a workpiece W whose one surface (front surface) Wa is sucked and held by a table 30 to a transport member 4, and a transport for sucking the workpiece W. A step of measuring the suction pressure of the member 4 and comparing it with the threshold value is provided, and when the measured suction pressure is higher than the threshold value, it is determined that no foreign matter adheres to the suction surface 400a of the transport member 4. When the suction of the holding table 30 is stopped, the work piece W is delivered to the transfer member 4, and the measured suction pressure is lower than the threshold value, foreign matter is attached to the suction surface 400a of the transfer member 4. A method for transporting a work piece, in which the step of stopping the suction of the work piece 4 and stopping the delivery of the work piece W to the transport member 4 is performed. [Selection diagram] FIG. 5

Description

  The present invention relates to a method for transferring a workpiece, which transfers a workpiece held on a holding table to a transport member and transports the workpiece.

  In the process of manufacturing a semiconductor device, streets (planned division lines) are formed in a grid pattern on the surface of a workpiece, and devices such as ICs and LSIs are formed in regions defined by the streets. After each of these workpieces has its back surface ground and thinned to a predetermined thickness, it is divided along a street by a cutting device or the like to manufacture individual semiconductor device chips (for example, see Patent Document 1). 1).

JP 2007-134390 A

  In the manufacture of semiconductor devices, cutting, grinding, cleaning, inspection, or the like is performed in each process while a workpiece is held on a holding table. Then, after each step is performed, the workpiece is transferred from the holding table to the transfer member, and is transferred to the holding table of the device used in the next process by the transfer member while being suction-held on the suction surface of the transfer member. It is transported or stored in a wafer cassette.

  When a foreign object such as processing debris is present between the suction surface of the transfer member and the suction surface of the work piece when the work piece is transferred from the holding table to the transfer member, the transfer member is not processed. When the workpiece is sucked and held, stress concentrates on a portion of the workpiece surface where the foreign matter is present, and cracks and cracks are generated in the workpiece, which leads to defective products.

  Therefore, when the workpiece held on the holding table is transferred to the transport member and transported, foreign substances such as processing chips exist between the suction surface of the transport member and the suction surface of the workpiece. Even so, there is a problem that a crack or a crack due to a foreign substance is not generated in a workpiece.

  The present invention for solving the above-mentioned problems is a method of transferring a workpiece, one side of which is transferred to a transport member by transferring the workpiece held by a holding table, wherein the workpiece is suction-held by the holding table. A conveying member suction step of adsorbing the other surface of the workpiece to the conveying member, and a suction pressure of the conveying member for suctioning the other surface of the workpiece held by the holding table; Measuring the suction pressure and comparing the suction pressure with a pre-registered threshold value. If the suction pressure measured in the suction pressure measurement step is higher than the threshold value, It is determined that no foreign matter has adhered to the suction surface of the member, the suction of the holding table is stopped, and a workpiece transfer step of transferring the workpiece to the transport member is performed. Measured adsorption If the force is lower than the threshold value, it is determined that foreign matter is attached to the suction surface of the transfer member, the suction of the transfer member is stopped, and the transfer of the workpiece to the transfer member is stopped. A method of transporting a workpiece, characterized by performing a delivery stopping step.

  A method of transporting a workpiece according to the present invention includes a transport member suction step of suctioning the other surface of a workpiece, one surface of which is suction-held by a holding table, to a transport member, and a suction member being suction-held by the holding table. Measuring the suction pressure of the transfer member that suctions the other surface of the workpiece in the held state, and comparing the suction pressure with a pre-registered threshold value. If the measured suction pressure is higher than the threshold value, it is determined that no foreign matter is attached to the suction surface of the transport member, the suction of the holding table is stopped, and the workpiece is transferred to the transport member. When the transfer step is performed and the suction pressure measured in the suction pressure measurement step is lower than the threshold value, it is determined that foreign matter is attached to the suction surface of the transport member, the suction of the transport member is stopped, and the transfer member is stopped. Workpiece transport section By performing the delivery stop step of stopping delivery to the workpiece, there is a case where foreign matter such as processing waste exists between the suction surface of the transport member and the other surface which is the suction surface of the workpiece. Even if there is, it is possible to prevent cracks and cracks from occurring in the workpiece due to foreign matter.

Sectional view for explaining a state in which the back surface of the workpiece sucked and held by the holding table is sucked to the transport member when no foreign matter exists between the suction surface of the transport member and the back surface of the workpiece. It is. In the case where foreign matter is present between the suction surface of the transfer member and the work piece or in the case where no foreign matter is present, the pressure gauge was measured while the work piece transfer method was being performed. 6 is a graph showing a change in suction pressure of a conveying member over time. FIG. 9 is a cross-sectional view illustrating a state in which suction of the holding table is stopped and a workpiece is delivered to the transport member when no foreign matter exists between the suction surface of the transport member and the back surface of the workpiece. . FIG. 4 is a cross-sectional view illustrating a state in which a back surface of a workpiece sucked and held by a holding table is sucked to a transport member when a foreign object exists between a suction surface of the transport member and a back surface of the workpiece. It is. A description will be given of a state in which the suction of the transport member is stopped and the delivery of the workpiece to the transport member is stopped when a foreign object exists between the suction surface of the transport member and the back surface of the workpiece. It is sectional drawing. FIG. 9 is a cross-sectional view illustrating a state in which the back surface of the workpiece is sucked by the suction surface of the transport member in the conventional method of transporting the workpiece. In the conventional method of transporting a workpiece, immediately after the transport member sucks and holds the workpiece on the suction surface, the suction holding of the workpiece by the holding table is stopped. FIG. 4 is a cross-sectional view for explaining a state in which only the encircling conveying member sucks and holds the workpiece.

  The holding table 30 shown in FIG. 1 is provided in, for example, a grinding device that grinds and thins a workpiece W with a rotating grinding wheel. The holding table 30 is a cutting device that cuts the workpiece W by cutting the rotating cutting grindstone with respect to the workpiece W. A laser processing device for performing processing, a polishing device for polishing the workpiece W with a polishing pad, a tape mounter for attaching a protective tape to the workpiece W, or a protective tape attached to the workpiece W is expanded. The apparatus may be provided in an expanding device or the like that separates the workpiece W by applying an external force to the workpiece W.

  The workpiece W is, for example, a circular plate-shaped semiconductor wafer using silicon as a base material, and one surface Wa of the workpiece W facing downward in FIG. 1 (the surface Wa in the present embodiment). Above, devices (not shown) are formed in a grid-like area defined by the dividing lines. The surface Wa of the workpiece W is protected by, for example, attaching a protection tape (not shown). The other surface Wb (the back surface Wb in the present embodiment) of the workpiece W facing upward in FIG. 1 is, for example, a ground surface that has already been ground. The workpiece W is not limited to the example shown in the present embodiment.

The holding table 30 has, for example, a circular outer shape, and includes a holding section 300 made of a porous member or the like and holding the workpiece W by suction, and a frame body 301 surrounding and supporting the holding section 300. The holding unit 300 communicates with a first suction source 39, which is a vacuum generator such as a compressor or an ejector, via an air flow path 390. In FIG. 1, when the first suction source 39 operates, the suction force generated by the first suction source 39 is transmitted to the holding surface 300 a that is the exposed surface of the holding unit 300, and the holding table 30 is held. The surface Wa of the workpiece W is suction-held on the surface 300a.
The holding table 30 is not limited to the example shown in the present embodiment, and may be a holding table in which a suction groove is formed in a holding surface or a pin chuck table in which a holding surface is formed by a plurality of support pins. Is also good.

  For example, an air source 38 capable of supplying compressed air is connected to the air flow path 390. The air source 38 is used when the workpiece W sucked and held by the holding table 30 is separated from the holding surface 300a. That is, the air supplied from the air source 38 to the air flow path 390 reaches the holding section 300 through the air flow path 390, and is ejected upward from the holding surface 300a. The workpiece W is pushed up from the holding surface 300a by this air ejection pressure, and the vacuum suction force remaining between the holding surface 300a and the workpiece W (the vacuum suction remaining after stopping the suction by the first suction source 39). Force) is eliminated, and the workpiece W can be reliably detached from the holding table 30. The air flow path 390 is provided with, for example, a switching valve (not shown). The switching operation of the switching valve causes the air flow path 390 to be connected to the first suction source 39 and the air flow path 390 to be connected. It is possible to switch between the state connected to the air source 38

The transport member 4 shown in FIG. 1 includes, for example, an arm portion 41 that supports the transport pad 40, and a transport pad 40 that is disposed on the lower surface side of the arm portion 41 and that suction-holds the workpiece W.
The transport pad 40 has, for example, a circular outer shape, and includes a suction unit 400 made of a porous member or the like and sucking the workpiece W, and a frame 401 surrounding and supporting the suction unit 400. The suction unit 400 communicates with a second suction source 49, which is a vacuum generator such as a compressor or an ejector, via a suction path 490. When the second suction source 49 operates, the suction force generated by the second suction source 49 is transmitted to the flat suction surface 400a which is the exposed surface of the suction unit 400, and the transport member 4 is moved to the suction surface 400a. The back surface Wb of the workpiece W sucked and held on the holding table 30 can be sucked. The diameter of the suction surface 400a is set smaller than the diameter of the workpiece W, for example.

For example, on the suction path 490, a pressure gauge 48 that measures the pressure of the air flowing in the suction path 490, that is, the suction pressure of the transport member 4 that suctions the back surface Wb of the workpiece W is provided. The pressure gauge 48 is electrically connected to a pressure determination unit 47 composed of a CPU, a storage element, and the like, and measures measurement information on the pressure in the suction path 490 while the transport member 4 is operating. It can be sent to the judgment unit 47 sequentially.
The threshold value (for example, -50 MPa) of the suction pressure of the transport member 4 that suctions the back surface Wb of the workpiece W sucked and held on the holding table 30 is set in the pressure determination unit 47 in advance. Have been. Note that the role of the pressure determination unit 47 may be fulfilled by an operator who stores the threshold value by monitoring the scale of the pressure gauge 48.

  The arm portion 41 is movable in a horizontal direction and a vertical direction (Z-axis direction) by a moving unit (not shown). The arm 41 and the frame 401 of the transport pad 40 are connected by a fixing bolt 43. In the example shown in the present embodiment, a spring 44 is provided between the arm 41 and the frame 401 of the transport pad 40. It is arranged. The spring 44 contracts when the transport pad 40 comes into contact with the workpiece W in order to hold the workpiece W by suction, and accordingly, the arm portion 41 slightly lowers relatively to the fixing bolt 43. This prevents the transport pad 40 from being heavily weighted on the workpiece W, and prevents the workpiece W from being damaged by the pressing force received from the transport pad 40. Note that the transport member 4 may be configured without the spring 44.

  Hereinafter, as shown in FIG. 1, when there is no foreign matter between the suction surface 400 a of the transport member 4 and the back surface Wb of the workpiece W, the workpiece Wa whose front surface Wa is held by the holding table 30 Each step of the method of transporting the workpiece W according to the present invention in which the workpiece W is delivered to the transport member 4 and transported will be described. The method of transporting the workpiece W according to the present invention includes transporting the workpiece from one apparatus to another, or holding table 30 in one apparatus (for example, when the holding table 30 is a processing table). From the holding table 30 (for example, when the holding table 30 is a cleaning table) to the wafer cassette.

(1) Transfer Member Suction Step First, the back surface Wb of the workpiece W whose front surface Wa is suction-held on the holding table 30 is suctioned to the transfer member 4. That is, the transport member 4 is moved in the horizontal direction by a moving unit (not shown), and the transport pad 40 is positioned above the workpiece W such that the center of the transport pad 40 substantially matches the center of the workpiece W. . When the second suction source 49 operates, the suction force generated by the second suction source 49 is transmitted to the suction surface 400a of the transport pad 40. Further, the measurement of the suction pressure of the conveying member 4 by the pressure gauge 48 is started, and the measurement information is sequentially transmitted to the pressure determination unit 47.
A graph G1 shown by a two-dot chain line shown in FIG. 2 indicates the transfer of the workpiece according to the present invention when no foreign matter exists between the suction surface 400a of the transport member 4 and the back surface Wb of the workpiece W. 6 is a graph showing a change over time of the suction pressure of the conveying member 4 measured by the pressure gauge 48 during the execution of the method. At the start of the transfer member suction step (at 0 seconds), the suction pressure of the transfer member 4 measured by the pressure gauge 48 is a low (weak) value of about -2 MPa. The suction pressure is represented by a value of-(negative), and the higher the value of-(negative), the stronger the force.

  Further, after the transport pad 40 descends in the -Z direction to a height position where the suction surface 400a of the transport pad 40 shown in FIG. 1 contacts the back surface Wb of the workpiece W, the descent stops at the height position. . Then, by the suction force generated by the second suction source 49 and transmitted to the suction surface 400a, the transport member 4 suctions the back surface Wb of the workpiece W on the suction surface 400a.

(2) Suction Pressure Measuring Step In a state in which the conveying member 4 sucks the back surface Wb of the workpiece W on the suction surface 400a and the workpiece W is continuously suction-held by the holding table 30, the conveying member 4 The value measured by the pressure gauge 48 (for example, the value measured about 5 seconds after the start of the conveyance member suction step) that is higher than the threshold value (-50 MPa) as shown in the graph G1 of FIG. (For example, about −60 MPa). This is because although the workpiece W is drawn downward by the holding table 30, no foreign matter exists between the suction surface 400a of the transport member 4 and the back surface Wb of the workpiece W, and the suction surface This is because no vacuum leak occurs between 400a and the back surface Wb of the workpiece W. Then, the pressure determination unit 47, which is successively comparing the measured value sent from the pressure gauge 48 with the threshold value, adsorbs the transport member 4 while the workpiece W is being suction-held on the holding table 30. It is determined that the pressure has become higher than the threshold.

(3) Workpiece Delivery Step When the pressure determination unit 47 that compares the suction pressure with the pre-registered threshold value determines that the suction pressure has become higher than the threshold value as described above, the suction surface 400a of the transport member 4 It is further determined that no foreign matter has adhered to the. When the pressure determination unit 47 makes the determination, control is performed to stop the holding and holding of the workpiece W by the holding table 30. That is, the first suction source 39 stops, or the switching valve (not shown) provided in the air flow path 390 switches the air flow path 390 to a state in which the air flow path 390 is not communicated with the first suction source 39. Further, as shown in FIG. 3, the air source 38 supplies compressed air to the air flow path 390, and the air suction force remaining between the holding surface 300a and the workpiece W by the air ejected from the holding surface 300a. Is removed, the workpiece W is sucked and held only on the suction surface 400a of the transport member 4, and the workpiece W is transferred to the transport member 4.

As shown in FIG. 3, when the suction holding of the workpiece W by the holding table 30 is released, the pressure of the transport member 4 that is suctioning the back surface Wb of the workpiece W that is measured by the pressure gauge 48 is measured. The suction pressure value (for example, a measured value after a lapse of about 30 seconds from the start of the conveyance member suction step) sharply increases to, for example, about -95 MPa as shown in a graph G1 in FIG. This is because there is no foreign matter between the suction surface 400a of the conveying member 4 and the back surface Wb of the workpiece W, and a vacuum leak occurs between the suction surface 400a and the back surface Wb of the workpiece W. This is due to the fact that the suction holding of the workpiece W by the holding table 30 has been released (the force for pulling the workpiece W downward has been released).
Then, as the measured value sent from the pressure gauge 48 to the pressure determination unit 47 further increases as described above, the pressure determination unit 47 completes the transfer of the workpiece W to the transport member 4, and Only the member 4 holds the workpiece W by suction, and it is determined that the transport member 4 can be moved. The reason why the determination is performed by the pressure determination unit 47 is that the transport member 4 that suctions and holds the workpiece W is performed in a state where the workpiece W is not completely detached from the holding table 30. This is because the workpiece W may be damaged.
Then, control for raising the transport pad 40 and further moving the transport pad 40 in the horizontal direction is performed.

  Hereinafter, as shown in FIG. 4, when the foreign matter M exists between the suction surface 400 a of the transport member 4 and the back surface Wb of the workpiece W, the surface Wa held on the holding table 30 Each step of the method of transporting the workpiece W according to the present invention in which the workpiece W is delivered to the transport member 4 and transported will be described. In addition, the foreign matter M is processing scraps that cannot be completely cleaned during the previously applied processing and adheres to the back surface Wb of the workpiece W, or tape scraps that adhere to the suction surface 400a of the transport member 4 or the like. In the present embodiment, the size is, for example, about 150 μm.

(1) Transfer Member Suction Step First, the back surface Wb of the workpiece W whose front surface Wa is suction-held on the holding table 30 is suctioned to the transfer member 4. That is, the transport member 4 moves in the horizontal direction, and the transport pad 40 is positioned above the workpiece W such that the center of the transport pad 40 substantially matches the center of the workpiece W. When the second suction source 49 operates, the suction force is transmitted to the suction surface 400 a of the transport pad 40. Further, the measurement of the suction pressure of the transport member 4 by the pressure gauge 48 is started, and the measurement information is sequentially transmitted to the pressure determination unit 47.
A graph G2 indicated by a dashed line in FIG. 2 indicates that the foreign matter M is present between the suction surface 400a of the transport member 4 and the back surface Wb of the workpiece W according to the present invention. 6 is a graph showing a change over time of the suction pressure of the conveying member 4 measured by the pressure gauge 48 during the execution of the method. At the start of the transfer member suction step (at 0 seconds), the suction pressure of the transfer member 4 measured by the pressure gauge 48 is a low (weak) value of about -2 MPa.

  Further, after the transport pad 40 descends in the -Z direction to a height position where the suction surface 400a of the transport pad 40 contacts the back surface Wb of the workpiece W, the descending stops at the height position. In this state, the foreign matter M is sandwiched between the suction surface 400a of the transport pad 40 and the back surface Wb of the workpiece W. Then, by the suction force generated by the second suction source 49 and transmitted to the suction surface 400a, the transport member 4 suctions the back surface Wb of the workpiece W with the foreign matter M sandwiched between the suction surfaces 400a.

(2) Suction Pressure Measuring Step In a state in which the conveying member 4 sucks the back surface Wb of the workpiece W on the suction surface 400a and the workpiece W is continuously suction-held by the holding table 30, the conveying member 4 The measured value of the pressure gauge 48 for measuring the suction pressure (for example, the measured value when about 5 seconds have passed since the start of the conveyance member suction step) sharply rises as shown in a graph G2 in FIG. However, the measured value is, for example, only about −40 MPa, which is lower than the threshold −50 MPa. This is because the workpiece W is suction-held by the holding table 30, so that the workpiece W does not sufficiently fit into the suction surface 400a of the transport member 4 and the suction surface 400a of the transport member 4 This is because the presence of the foreign matter M between the workpiece W and the rear surface Wb causes a vacuum leak between the suction surface 400a and the rear surface Wb of the workpiece W. Then, the pressure determination unit 47, which is successively comparing the measured value sent from the pressure gauge 48 with the threshold value, adsorbs the transport member 4 while the workpiece W is being suction-held on the holding table 30. It is determined that the pressure has become lower than the threshold.

(3) Delivery Stop Step When the pressure determination unit 47 that compares the suction pressure with the previously registered threshold value determines that the suction pressure has become lower than the threshold value as described above, the foreign matter is placed on the suction surface 400a of the conveying member 4. It is further determined that M is attached. As a result, control for stopping the suction holding of the workpiece W by the transport member 4 is performed. That is, as shown in FIG. 5, when the second suction source 49 is stopped, the suction pressure of the conveying member 4 is eliminated, and the workpiece W is sucked and held only on the holding surface 300a of the holding table 30, and the workpiece W is sucked and held. Delivery of W to the transport member 4 is stopped.
Therefore, the suction pressure value of the transport member 4 that does not suction the back surface Wb of the workpiece W measured by the pressure gauge 48 (for example, a measured value after about 30 seconds have elapsed from the start of the transport member suction step) is shown in FIG. As shown in a graph G2, for example, the temperature rapidly drops to about -2 MPa.
For example, after the delivery of the workpiece W to the transport member 4 is stopped, the suction surface 400a of the transport member 4 is cleaned by an operator or the like to remove the foreign matter M, or the workpiece W is placed on the holding table 30. Is transferred to a cleaning device or the like, where the back surface Wb is cleaned, and the foreign matter M is removed.

  Here, delivery of the workpiece W to the transport member 4 in the conventional method of transporting the workpiece will be described below with reference to FIGS. In the transfer of the workpiece W to the transport member 4 in the conventional method of transporting the workpiece, as shown in FIG. 6, a height position at which the suction surface 400a of the transport pad 40 contacts the back surface Wb of the workpiece W. After the transport pad 40 has descended in the -Z direction, the transport pad 40 stops at the height position. Then, by the suction force generated by the second suction source 49 and transmitted to the suction surface 400a, the transport member 4 suctions the back surface Wb of the workpiece W on the suction surface 400a. Immediately after the transfer member 4 suction-holds the workpiece W on the suction surface 400a, control is performed to stop the suction holding of the workpiece W by the holding table 30. That is, the first suction source 39 is stopped, and as shown in FIG. 7, the air source 38 supplies the compressed air to the air flow path 390, and the compressed air is blown from the holding surface 300a to cover the holding surface 300a. The vacuum suction force remaining between the workpiece W and the workpiece W is eliminated, the workpiece W is sucked and held only by the suction surface 400a of the transport member 4, and the workpiece W is transferred to the transport member 4. Become.

As a result, the transport member 4 moves the workpiece W in a state in which the workpiece W is sufficiently adapted to the suction surface 400a, that is, in a state in which the workpiece W covers and surrounds the foreign matter M on the suction surface 400a. The suction is held by the suction surface 400a. Then, in a state where the suction holding of the workpiece W by the holding table 30 is released, when the pressure gauge 48 measures the suction pressure of the transport member 4 that is sucking the back surface Wb of the workpiece W on the suction surface 400a, The measured value of the pressure gauge 48 sharply rises to, for example, about -95 MPa. This is because the workpiece W covers and surrounds the foreign matter M on the suction surface 400a even if the foreign matter M exists between the suction surface 400a of the conveying member 4 and the back surface Wb of the workpiece W. This is because no vacuum leak occurs between the suction surface 400a and the back surface Wb of the workpiece W. As a result, it is determined that only the transport member 4 is holding the workpiece W by suction, and control is performed to raise the transport pad 40 and move the transport pad 40 further in the horizontal direction.
As described above, the workpiece W can be transported by the transport member 4, but the workpiece W releases the foreign matter M on the suction surface 400 a by releasing the suction holding of the workpiece W by the holding table 30. As a result, the portion of the workpiece W where the foreign matter M is present is subjected to a load due to deformation and cracks, and a crack extends from the portion to the periphery.

  On the other hand, as described above, the method of transporting the workpiece according to the present invention employs the method of transporting the workpiece W whose one surface Wa (the surface Wa in the present embodiment) is suction-held on the holding table 30. A conveying member suction step of adsorbing one surface Wb (the back surface Wb in the present embodiment) to the conveying member 4 and a conveying member suctioning the back surface Wb of the workpiece W held by the holding table 30; And measuring the suction pressure of step No. 4 and comparing the suction pressure with a pre-registered threshold value. If the suction pressure measured in the suction pressure measurement step is higher than the threshold value, the transfer is performed. It is determined that no foreign matter has adhered to the suction surface 400a of the member 4, the suction of the holding table 30 is stopped, and a workpiece W transfer step of transferring the workpiece W to the transport member 4 is performed, and the suction pressure is measured. Step If the suction pressure measured in step (1) is lower than the threshold value, it is determined that the foreign matter M is attached to the suction surface 400a of the transport member 4, the suction of the transport member 4 is stopped, and the transport member of the workpiece W is stopped. By performing the delivery stop step of stopping delivery to the work 4, foreign matter M such as processing waste exists between the suction surface 400 a of the transport member 4 and the back surface Wb which is the suction surface of the workpiece W. Even in this case, the workpiece W is forcibly adapted to the suction surface 400a of the conveying member 4 so as not to be adsorbed, and cracks and cracks are generated in the workpiece W due to the foreign matter M. It is possible to prevent it from being performed.

Note that the method of transporting the workpiece according to the present invention is not limited to the above example, and the configurations of the holding table 30 and the transport member 4 illustrated in the accompanying drawings are not limited thereto. Instead, it can be appropriately changed within a range where the effects of the present invention can be exhibited.
For example, one surface of the workpiece W sucked and held by the holding table 30 is the back surface Wb, and the other surface of the workpiece W exposed upward on the holding table 30 (in this case, When the surface Wa) is adsorbed to the transport member 4, the method of transporting a workpiece according to the present invention may be performed.

W: Workpiece Wa: One face (front face) of the workpiece Wb: The other face (backside) of the workpiece
30: holding table 300: holding section 300a: holding surface 301: frame
39: first suction source 390: air flow path 38: air source 4: transport member 40: transport pad 400: suction section 400a: suction surface 401: frame body 41: arm section 43: fixing bolt 44: spring 49: spring 49 2 suction source 490: suction path 48: pressure gauge 47: pressure determination unit M: foreign matter

Claims (1)

A method of transporting a workpiece in which one surface is transferred to a transport member while the workpiece held by the holding table is delivered to the transport member,
A transfer member suction step of suctioning the other surface of the workpiece suction-held on the holding table to the transfer member,
A suction pressure measuring step of measuring a suction pressure of the transfer member for sucking the other surface of the workpiece in a state of being suction-held on the holding table, and comparing the suction pressure with a previously registered threshold value; ,
If the suction pressure measured in the suction pressure measuring step is higher than the threshold value, it is determined that no foreign matter is attached to the suction surface of the transport member, the suction of the holding table is stopped, and Performing a workpiece transfer step of transferring an object to the transport member,
If the suction pressure measured in the suction pressure measuring step is lower than the threshold value, it is determined that foreign matter is attached to the suction surface of the transfer member, the suction of the transfer member is stopped, and A method of transporting a workpiece, comprising performing a delivery stop step of stopping delivery of the workpiece to the transport member.

Images