JP4625704B2 - Grinding equipment - Google Patents

Description

  The present invention relates to a grinding device and a size determination method for a workpiece holding portion, and more particularly, to a grinding device capable of selectively mounting a plurality of workpiece holding portions and a size determination method for the workpiece holding portion.

  In a semiconductor device manufacturing process, circuits such as ICs and LSIs are formed in a large number of regions arranged in a grid on the surface of a substantially disc-shaped semiconductor wafer, and each region where the circuit is formed is defined on a predetermined street. Individual semiconductor chips are manufactured by dicing along a cutting line. At this time, in order to improve the heat dissipation of the semiconductor chip, it is desirable to form the semiconductor chip as thin as possible. In addition, for example, in order to enable downsizing of a mobile phone, a smart card, a personal computer, etc. using a plurality of semiconductor chips, the semiconductor chip is required to be thin. Therefore, before the semiconductor wafer is divided into individual semiconductor chips, the back surface thereof is ground and processed to a predetermined thickness (for example, 100 to 50 μm). The semiconductor wafer thus processed thinly has a reduced rigidity and is bent, so that it becomes difficult to carry it in an apparatus such as a grinding apparatus.

  For example, in a grinding apparatus that grinds the back surface of a semiconductor wafer, the semiconductor wafer that has been thinly ground is transported to a cleaning unit, and the semiconductor wafer that has been cleaned by the cleaning unit is transported into a cassette. Generally, the conveying means for conveying the ground semiconductor wafer to the cleaning unit conveys the lower surface (circuit surface) of the semiconductor wafer by suction and holding it on the upper surface of a U-shaped conveying hand.

  Recently, however, semiconductor wafers are becoming thinner. For this reason, when an extremely thin semiconductor wafer is transported while being sucked and held on the upper surface of a U-shaped wafer holding portion, for example, the outer peripheral portion hangs down due to the bending of the semiconductor wafer and is transported to the cassette shelf. There is a problem that the semiconductor wafer is damaged due to interference with the shelf.

  Therefore, in order to solve the above problem, the applicant of the present application forms a disk-shaped scoop type having substantially the same diameter as the semiconductor wafer to hold the semiconductor wafer and sucks and holds the outer periphery of the semiconductor wafer. A conveying means has been proposed (for example, Patent Document 1 and Patent Document 2). By such a transport means, the entire surface of the semiconductor wafer can be securely held, and the ultra-thin semiconductor wafer can be reliably transported without bending and causing warpage, and without damaging the semiconductor wafer. Can be housed inside.

  Further, when the thickness of the semiconductor wafer is reduced to 100 to 50 μm, there is a problem that when the semiconductor wafer is accommodated in a normal cassette having support grooves formed on both sides, the semiconductor wafer is bent and cannot be accommodated in the cassette. Therefore, recently, a technique for housing a semiconductor wafer in a special case called a coin stack carrier has been developed and put into practical use.

  This coin stack carrier is a case in which semiconductor wafers and partition paper wafers are alternately stacked so as to receive coins. The coin stack carrier is stored in a cylindrical case through the semiconductor wafer through an upper opening. To do. With such a configuration, even if the semiconductor wafer is processed to be extremely thin, it can be safely stored and transported.

  As a wafer transfer mechanism corresponding to this coin stack carrier, a C-shaped workpiece holding part having the same diameter as that of the semiconductor wafer is used, and suction is generated by generating negative pressure with the blast air and contacting the friction member. A wafer transfer mechanism that holds the outer periphery of a semiconductor wafer is proposed. With this wafer transfer mechanism, it is possible to prevent the outer peripheral portion from sagging, which was a problem when using the U-shaped wafer holding unit. In addition, it can be shared with coin stack carriers and ordinary cassettes.

On the other hand, recently, there is a tendency that the size of a semiconductor wafer as a workpiece is shifted from an 8 inch (200 mm) size, which has been the mainstream until now, to a 12 inch (300 mm) size. For this reason, semiconductor wafers of different sizes such as 8 inches and 12 inches have to be frequently replaced.

  Thus, with the diversification of workpieces, it has become necessary to grind various types of workpieces with a single grinding machine. For this reason, it is necessary to replace the workpiece holding part with the most appropriate one depending on the state.

JP 2003-133390 A JP 2003-303874 A

  However, an operator may attach an incorrect workpiece holding part to the attachment part. If the operation continues with the wrong workpiece holder attached, not only the cassette and workpiece holder may be damaged, but also the semiconductor wafer may be damaged.

  In order to prevent this, when the operator mounts the wrong workpiece holding portion on the mounting portion, it is necessary to stop the grinding apparatus and instruct the operator to mount the correct workpiece holding portion. For this purpose, it is indispensable that the grinding apparatus has a discrimination function for discriminating the type of the workpiece holding portion actually mounted on the conveying means.

  As such a discriminating function, for example, it is conceivable to provide a notch having a different shape in accordance with the type of the workpiece holding portion at the portion where the workpiece holding portion is fitted to the mounting portion. Then, the type of the workpiece holding portion is discriminated based on the type of the notch. Specifically, information on the correct workpiece holding portion is input to the grinding device in advance so that only the workpiece holding portion provided with the notch of the correct workpiece holding portion can be mounted. Thus, erroneous mounting can be prevented by changing the shape of the mounting portion of the workpiece holding portion. Further, for example, the type of the workpiece holding portion actually mounted is read based on the shape of the cutout of the workpiece holding portion, and compared with the information of the correct workpiece holding portion inputted in advance. As a result of the comparison, when the types of the workpiece holding portions do not match, the workpiece holding portion or the like can be prevented from being damaged by, for example, processing such as stopping the grinding device.

  The method of discriminating by the notch of the workpiece holding part as described above has an effect of reliably preventing erroneous mounting. However, when the types of workpiece holding parts increased, all the mounting parts of the conveying means had to be replaced, and the expandability was lacking. In addition, there is a problem that the internal structure of the transport means, particularly the wiring, becomes complicated and causes a failure.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to determine the type of the workpiece holding portion, and if there is an erroneous mounting, It is an object of the present invention to provide a new and improved grinding apparatus capable of preventing damage.

  In order to solve the above problems, according to one aspect of the present invention, a plurality of types of workpiece holding units that hold a workpiece, and a mounting unit that selectively mounts a plurality of types of workpiece holding units. And a workpiece holding unit and a moving unit that moves the mounting unit, and a grinding device comprising a plurality of types of workpiece holding units and / or a type of workpiece. Recognition means for recognizing the correct type of workpiece holder corresponding to the workpiece transport method and the workpiece attached to the attachment when the workpiece holder attached to the attachment is placed in the discrimination area. The discriminating means for discriminating the type of the workpiece holding unit, the type of the workpiece holding unit recognized by the recognition unit, and the type of the workpiece holding unit mounted on the mounting unit discriminated by the discriminating unit are different. Control means for stopping at least the transport means , Grinding apparatus is provided, characterized in that it comprises a.

  There are a plurality of types of workpiece holding parts (for example, wafer holding parts for holding semiconductor wafers) of the transfer means, and for example, they are properly used according to the type of workpieces and the method of accommodating them in the cassette. In order to determine that the correct workpiece holding portion is mounted among the plurality of types of workpiece holding portions, the grinding apparatus includes the above-described recognition means, determination means, and control means. The configuration. First, when the cassette is placed on the grinding apparatus, the recognition means recognizes, for example, the type of the semiconductor wafer that is the workpiece and the method of accommodating the cassette, and the mounting unit The type of the correct workpiece holder to be mounted on is recognized. Next, when the workpiece holding portion is mounted on the mounting portion by the operator, the type of the mounted workpiece holding portion is determined by the determining means. Then, the type of the work piece holding part recognized by the recognition means is compared with the kind of the work piece holding part discriminated by the discriminating means, so that the work piece holding part mounted on the mounting part is correct. Judge whether or not. When it is determined that the wrong workpiece holding portion is mounted, at least the conveying means of the grinding apparatus is stopped by the control means. Thereby, damage to a workpiece holding part, a cassette, and the workpiece itself can be prevented.

  The discriminating means includes size discriminating means for discriminating the size of the workpiece holding part mounted on the mounting part. By such size discrimination means, it is possible to discriminate which size of workpiece (for example, an 8-inch semiconductor wafer or a 12-inch semiconductor wafer) the workpiece holding portion mounted on the mounting portion corresponds to. It becomes possible.

  Further, the determining means includes shape determining means for determining the shape of the workpiece holding portion mounted on the mounting portion. With this shape discriminating means, it is possible to discriminate whether the shape of the workpiece holding portion mounted on the mounting portion is, for example, a C shape or a scoop type.

  The discriminating means may include, for example, a reflective optical sensor, and at least one reflective optical sensor may be disposed in a discriminating region for discriminating a workpiece holding unit mounted on the mounting unit. it can. Then, it is detected whether or not a part of the workpiece holding part mounted on the mounting part exists at a corresponding position of the reflective optical sensor disposed in the determination area. Thus, by combining the information detected by the plurality of reflective optical sensors, it is possible to determine the type of the workpiece holding portion mounted on the mounting portion.

  Even if the workpieces are the same size, there are multiple types of cassettes depending on the workpiece placement method or user specifications, so the size of the workpiece holder should be slightly changed. May be necessary. When the shape of the workpiece holding portion is, for example, a scoop type, the discrimination means cannot discriminate a slight difference in the size of the scoop type workpiece holding portion. Therefore, first, a distance to be used as a reference when determining the size of the scoop type workpiece holder is measured in advance. The reference distance includes the position when the position of the predetermined reflective optical sensor is projected on the horizontal plane when the scoop-type work holding part is located at the measurement position of the discrimination area, and the scoop-type work holding It is set as the linear distance which ties the position when the position of the arbitrary edge of a part is projected on a horizontal surface. Next, the scoop type workpiece holding part attached to the attachment part is moved along the straight line to the predetermined reflective optical sensor side and moved from the measurement position until it is no longer detected by the predetermined reflective optical sensor. Measure the distance. Thereafter, the distance stored in advance and the moved distance are compared to determine the size of the scoop type workpiece holding part mounted on the mounting part. With such a size determination method, it is possible to determine the size of the workpiece holding portion that cannot be determined by the normal size determination means without installing a new determination means.

  As described above, according to the present invention, it is possible to determine the type of the workpiece holding portion that is mounted, and when a wrong type of workpiece holding portion is mounted on the mounting portion of the conveying means, the grinding device By stopping at least the operation of the conveying means, it is possible to prevent the workpiece or the like from being damaged.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(First embodiment)
First, a grinding apparatus according to a first embodiment of the present invention will be described. FIG. 1 is a schematic perspective view of a grinding apparatus according to this embodiment. The grinding apparatus 1 is configured as an apparatus for grinding a back surface of a workpiece, for example, a semiconductor wafer 50. The semiconductor wafer 50 is, for example, a substantially disc-shaped silicon wafer such as 8 inches or 12 inches. The grinding apparatus 1 grinds the back surface (surface opposite to the circuit surface) of the semiconductor wafer 50 to reduce the thickness to, for example, 100 to 50 μm.

  Each component of the grinding apparatus 1 will be specifically described. As shown in FIG. 1, the grinding apparatus 1 includes, for example, a housing 2, a rough grinding unit 3, a finish grinding unit 4, for example, three chuck tables 6 installed on a turntable 5, and cassettes 11 and 12. A position table 13, transfer arms 17 and 18, transfer means 20, and a spinner cleaning device 40.

  The rough grinding unit 3 performs rough grinding on the back surface of the semiconductor wafer 50 by pressing the back surface of the semiconductor wafer 50 held on the chuck table 6 while rotating the grinding wheel 3b mounted on the lower end of the spindle 3a. . At the same time, the finish grinding unit 4 presses the back surface of the semiconductor wafer 50 after the rough grinding while rotating the grinding wheel 4b mounted on the spindle 4a, thereby increasing the back surface of the semiconductor wafer 50. Finish grinding with precision. As described above, the grinding apparatus 1 according to the present embodiment includes the two grinding units 3 and 4. However, the present invention is not limited to this example, and the grinding apparatus 1 includes one or three or more grinding units. It can also be configured.

  The turntable 5 is a table on a circular plate provided on the upper surface of the housing 2 and can be rotated in the horizontal direction. In the turntable 5, for example, three chuck tables 6 are disposed at equal intervals with a phase angle of 120 degrees, for example. The chuck table 6 has a vacuum chuck on the upper surface thereof, and holds the semiconductor wafer 50 placed thereon by vacuum suction. The chuck table 6 can be rotated in the horizontal direction by a rotation drive mechanism (not shown) during grinding. In this configuration, the chuck table 6 is sequentially moved to the carry-in / carry-out region A, the rough grinding region B, the finish grinding region C, and the carry-in / carry-out region A as the turntable 5 rotates.

  The cassettes 11 and 12 are containers for semiconductor wafers having a plurality of slots. The cassette 11 accommodates the semiconductor wafer 50 before grinding, while the cassette 12 accommodates the semiconductor wafer 50 after grinding. When the ground semiconductor wafer 50 is accommodated in the cassette 12, the circuit surface is accommodated with the circuit surface facing upward (the ground processing surface is directed downward) or the circuit surface is directed downward (grinded). Or with the machined surface facing upward). For example, a type of wafer holding unit 22 suitable for this accommodation method is selected.

  The position table 13 is a table on which the semiconductor wafer 50 taken out from the cassette 11 is temporarily placed. The position table 13 includes, for example, a center alignment mechanism that aligns the center position of the semiconductor wafer 50 by simultaneously reducing the diameter of six pins toward the center of the table. Further, a discriminating means 30 for discriminating the type of the wafer holding unit 22 which is a feature of the present invention is provided. Details of the determination means 30 will be described later.

  The transfer arms 17 and 18 are provided with an adsorbing unit that adsorbs the semiconductor wafer 50 from above, an arm unit that supports the adsorbing unit, and a rotation drive unit that rotates the arm unit in the horizontal direction. The transfer arm 17 transfers the semiconductor wafer 50 before grinding, which is placed on the position table 13, and places it on the chuck table 6 located in the loading / unloading area A. Further, the transfer arm 18 transfers the ground semiconductor wafer 50 placed on the chuck table 6 located in the carry-in / out area A and places it on the spinner table 42 of the spinner cleaning device 40.

  The transfer means 20 is a transfer means (robot pick) 20 provided with a wafer holder 22 (for example, a C-shaped hand) provided with suction pads (not shown). The transfer means 20 picks up the semiconductor wafer 50 by suction holding it by the wafer holding unit 22. Then, the semiconductor wafer 50 before grinding is transferred from the cassette 11 to the position table 13. Further, the ground semiconductor wafer 50 is transferred from the spinner table 42 to the cassette 12.

  Here, the conveying means 20 will be described in detail with reference to FIG. FIG. 2 is an explanatory view showing the conveying means 20 according to the present embodiment. As shown in FIG. 2, the transfer means 20 includes a wafer holding unit 22 for holding a semiconductor wafer 50, a mounting unit 24 for selectively mounting a plurality of types of wafer holding units 22, a wafer holding unit 22 and a mounting unit. And a moving part 26 for moving 24.

  The wafer holding unit 22 is for holding the semiconductor wafer 50, and there are a plurality of types of wafer holding units 22 having different shapes and sizes. Depending on the manner in which the semiconductor wafer 50 is accommodated in the cassette 12, for example, a wafer holding unit 22 having a different shape such as a C-shaped wafer holding unit 22a or a rice paddle type wafer holding unit 22c is used. Used selectively. Further, the wafer holders 22 having different sizes are selectively used in accordance with the size (for example, 8 inches or 12 inches) of the semiconductor wafer 50 to be processed. Furthermore, even when the same size semiconductor wafer 50 is handled, the method of placing the workpieces is different, or the sizes of the cassettes 11 and 12 that accommodate the semiconductor wafer 50 are different depending on the specifications of the user. For this reason, a wafer holding unit 22 having a slightly different size may be used. Thus, there are various types of wafer holders 22.

  The mounting unit 24 is mounted so that the wafer holding unit 22 is fitted. As shown in FIG. 2, a plurality of types of wafer holders 22 to be exchanged according to the size of the semiconductor wafer 50 and its accommodation method are selectively mounted on the mounting unit 24.

  The moving unit 26 is, for example, an arm-type moving unit, and a mounting unit 24 is provided at the tip of the moving unit 26. A motor for driving is provided at each link between the links constituting the arm. By rotating each link in the horizontal direction by this motor, the conveying means 20 can operate in the XY plane. Therefore, the semiconductor wafer 50 can be moved to a predetermined position. For example, a servo motor mechanism is used to drive the moving unit 26, and the distance that the moving unit 26 is moved can be accurately measured.

  Heretofore, the grinding apparatus 1 according to the present embodiment has been described. The grinding apparatus 1 has a function of discriminating the type of the wafer holding unit 22 in order to prevent damage to the wafer holding unit 22 and the like due to erroneous mounting of the wafer holding unit 22. As described above, the type of the wafer holding unit 22 to be used differs depending on how the semiconductor wafer 50 is accommodated in the cassettes 11 and 12 and the size of the semiconductor wafer 50. Here, the reason why a plurality of types of wafer holding units 22 are required will be described in detail.

  The wafer holding unit 22 mounted on the mounting unit 24 of the grinding apparatus 1 is mounted according to the semiconductor wafer transfer method. The transfer method of the semiconductor wafer 50 differs depending on the processing method of the semiconductor wafer 50. For example, a semiconductor wafer 50 that has been subjected to a DBG (Dicing Before Grinding) process for reducing the thickness of the semiconductor wafer 50 after dicing has an extremely thin thickness compared to the semiconductor wafer 50 that has undergone normal dicing. In addition, it is divided into chips. For this reason, even if the semiconductor wafer 50 is held by a tape, the shape of the wafer holding portion 22 can be held only by a shape in which the holding portion exists in the center portion, that is, a scoop type. As described above, it is necessary to mount the wafer holding unit 22 compatible with the transfer method of the semiconductor wafer 50 on the mounting unit 24.

  If the operator attaches the wrong wafer holding unit 22 to the mounting unit 24, if the operation is continued as it is, not only the cassettes 11 and 12 and the wafer holding unit 22 are damaged, but also the semiconductor wafer 50 is damaged. . For example, if a wafer holding unit 22 having a size larger than the correct size of the wafer holding unit 22 is mistakenly mounted on the mounting unit 24, the cassettes 11 and 12 and the wafer holding unit 22 come into contact with each other and both are damaged. There is a fear.

  In particular, when a wafer holding unit 22 having a different shape such as a scoop type or a C-shape is erroneously mounted, the wafer holding unit 22 or the semiconductor wafer 50 comes into contact with the slots of the cassettes 11 and 12 and is damaged. . In particular, the operation of the transfer means 20 differs depending on whether the shape of the wafer holding unit 22 is a scoop type or a C shape.

  For example, when moving the semiconductor wafer 50 from the spinner cleaning unit 40 to the cassette 12, the scoop type wafer holding unit 22 moves the semiconductor wafer 50 placed on the spinner table 42 with the processing surface facing upward on the processing surface side. Adsorbed and transported. When inserting into the slot of the cassette 12, the semiconductor wafer 50 is usually accommodated with the circuit surface facing downward.

  On the other hand, the C-shaped wafer holding unit 22 sucks and transports the semiconductor wafer 50 placed on the spinner table 42 with the processing surface facing upward from the lower circuit surface side. When inserting into the slot of the cassette 12, the semiconductor wafer 50 is turned upside down and then accommodated with the circuit surface of the semiconductor wafer 50 facing upward.

  Therefore, for example, when the original C-shaped wafer holding unit 22 is mounted, if the scoop type wafer holding unit 22 is erroneously mounted, the wafer holding unit 22 contacts the spinner table 42 of the spinner cleaning unit 40 and is damaged. End up. On the other hand, if it is correct to attach the scoop type wafer holder 22 and the C-shaped wafer holder 22 is attached, the wafer holder 22 and the semiconductor wafer 50 are brought into contact with the slot of the cassette 12 and are damaged. End up.

  Further, when the semiconductor wafer 50 is accommodated with the circuit surface facing upward, the scoop type wafer holder 22 having a diameter smaller than the diameter of the semiconductor wafer 50 is used. At this time, when the semiconductor wafer 50 after grinding is inserted into the slot of the cassette 12, the semiconductor wafer 50 is turned upside down and then accommodated with the circuit surface of the semiconductor wafer 50 facing upward. Here, the scoop type wafer holding unit 22 is positioned below the semiconductor wafer 50 but has a small diameter so that it does not come into contact with the slot of the cassette 12 when placed.

  However, if the diameter of the scoop type is made smaller than that of the semiconductor wafer 50, the outer peripheral surface of the semiconductor wafer 50 is not held, and therefore, the diameter tends to be damaged. Since such a risk is involved, in consideration of safety, it is usually preferable to use a wafer having a diameter substantially the same as or slightly larger than that of the semiconductor wafer 50.

  In this way, depending on the mounting method of the semiconductor wafer 50, it is necessary to use different sizes of the scoop type wafer holder 22 even if the semiconductor wafer 50 has the same size. Since the transfer operation of the semiconductor wafer 50 differs depending on the size of the scoop type, if the wrong wafer holder 22 is mounted, even the semiconductor wafer 50 of the same size comes into contact with the slot of the cassette 12. .

  For the reasons described above, an appropriate type of wafer holding unit 22 must always be mounted on the mounting unit 24. For this reason, the grinding apparatus 1 according to the present embodiment has a function of determining whether or not the wafer holding unit 22 mounted on the mounting unit 24 is correct.

  The function for determining the type of the wafer holding unit 22 will be described in detail below based on FIGS. 3 and 4. FIG. 3 is a block diagram showing components for discriminating the type of the wafer holding unit 22 in the grinding apparatus 1 according to the present embodiment. FIG. 4 is an explanatory diagram showing the determination means 30 according to the present embodiment.

  As shown in FIG. 3, the grinding apparatus 1 according to the present embodiment includes a cassette discriminating means 10, a recognizing means 15, a conveying means 20, a discriminating means 30, a storage means 60, a comparing means 70, and a control means. 80 and a display unit 90. Below, the structure of each means for discriminating the kind of wafer holding part 22 is demonstrated.

  The cassette discriminating means 10 includes, for example, an identification mark for identifying the type of the cassettes 11 and 12 and a reading means (not shown) for identifying the recognition mark. For example, barcodes are attached to the cassettes 11 and 12 as identification marks for identifying the types of the cassettes 11 and 12. Then, the type of the cassettes 11 and 12 is discriminated by identifying the bar code by reading means (not shown). Further, for example, a plurality of contact pins (not shown) may be arranged at positions where the cassettes 11 and 12 are placed. At this time, the shapes of the cassettes 11 and 12 are made different for each type of the cassettes 11 and 12, or the cassettes 11 and 12 are processed so as to be different. And it discriminate | determines by the combination which the cassettes 11 and 12 press a contact pin.

  The recognition unit 15 includes a recognition unit (not shown). The recognition unit automatically recognizes the correct wafer holding unit 22 to be mounted on the mounting unit 24 based on the types of the cassettes 11 and 12 determined by the cassette determination unit 10. The type of the correct wafer holding unit 22 recognized at this time is stored in a storage unit (not shown) of the storage unit 60 for comparison with the actually mounted wafer holding unit 22.

  As described above, the transfer unit 20 includes the wafer holding unit 22 that holds the semiconductor wafer 50, the mounting unit 24 that selectively mounts a plurality of types of wafer holding units 22, the wafer holding unit 22, and the mounting unit 24. And a moving unit 26 to be moved.

  The discriminating means 30 is a means for discriminating the type of the wafer holding unit 22 mounted on the mounting unit 24, and includes, for example, a size determining unit 31 and a shape determining unit 33. The discriminating means 30 can be installed on the position table 13, for example. Details of the determination means 30 will be described later.

  The storage unit 60 includes a storage unit (not shown). In the storage unit, the correct type of the wafer holding unit 22 recognized by the recognition unit 15 is stored.

  The comparison means 70 has a comparison unit (not shown). In this comparison means 70, the wafer holding part 22 recognized by the recognition means 15 is compared with the wafer holding part 22 determined by the determination means 30.

  The control means 80 includes a control unit (not shown). When the wafer holding unit 22 recognized by the recognition unit 15 and the wafer holding unit 22 discriminated by the discriminating unit 30 are different, the control unit 80 transfers at least the grinding device 1 so as not to damage the semiconductor wafer 50 and the like. The means 20 is controlled to stop. At this time, in order to prompt the operator to replace the wafer holding unit 22, the display unit 90 is controlled to display the correct wafer holding unit 22.

  Here, the discrimination means 30 which is a feature of the present invention will be described in detail with reference to FIG.

  As shown in FIG. 4, on the position table 13, for example, a size discrimination sensor 32 constituting the size discrimination means 31, a shape discrimination sensor 34 constituting the shape discrimination means 33, and the semiconductor wafer 50 are placed in the discrimination area. A wafer presence / absence sensor 36 that detects whether the semiconductor wafer 50 has been positioned, a plurality of pins 37a and grooves 37 for aligning the semiconductor wafer 50 on the position table 13, and a vacuum that holds the semiconductor wafer 50 placed on the position table 13. A suction portion 38 is disposed.

  The size discrimination sensor 32 is a sensor for discriminating the size of the wafer holding unit 22 such as for an 8-inch semiconductor wafer or a 12-inch semiconductor wafer. The shape discrimination sensor 34 is a sensor for discriminating the shape of the wafer holding unit 22 such as a C shape or a scoop type. The sensors 32 and 34 are embedded on the position table 13 at positions corresponding to the size and shape of the wafer holder 22 to be determined.

  As the size discrimination sensor 32 and the shape discrimination sensor 34, for example, a reflection type optical sensor can be used. A reflective optical sensor, which is a non-contact sensor, has a projector and a light receiver, and outputs light from the projector. When the output light beam is reflected by the wafer holder 22, the reflected light beam reaches the light receiver and receives light. When the light beam is received, it is determined that the wafer holder 22 is present at the detection position of the reflective optical sensor. In the present embodiment, when the reflective optical sensor installed in the discrimination area receives the reflected light of the light emitted from itself, the fact that the wafer holder 22 exists at the corresponding position of the reflective optical sensor is utilized. To determine.

  For example, consider a case where the size discrimination sensor 32 discriminates the wafer holding unit 22 having two sizes of large and small. At this time, the size discriminating sensor 32 is installed on the optical path of the light beam emitted from the size discriminating sensor 32 at a position where it is present if it is a large wafer holder 22 and not present if it is a small wafer holder 22. As described above, by installing the size determination sensor 32 so that the presence or absence of detection of the wafer holding unit 22 differs according to the size of the wafer holding unit 22, the size of the wafer holding unit 22 can be determined. Become.

  Similarly, the shape determination sensor 34 is installed at a position where the shape can be determined depending on whether or not the shape determination sensor 34 detects the wafer holding unit 22. For example, the shape discriminating sensor 34 is installed at a position that does not detect the C-shaped wafer holding unit 22 but detects the C-shaped wafer holding unit 22.

  The type of the wafer holding unit 22 mounted on the mounting unit 24 can be determined by combining presence / absence of detection by a plurality of determination sensors (for example, the size determination sensor 32 and the shape determination sensor 34).

  Here, based on FIG. 5A-5D, the method to discriminate | determine the wafer holding part 22 using the discrimination means 30 is demonstrated concretely. Here, four wafer holding parts 22 of 12 inch C-shaped wafer holding part 22a, 8 inch C-shaped wafer holding part 22b, 12 inch scoop type wafer holding part 22c, and 8 inch scoop type wafer holding part 22d are discriminated. To do.

  In this example, the size determination sensor 32 determines whether the mounted wafer holder 22 is for 8 inches or 12 inches. At this time, if the wafer holder 22 for 12 inches is present on the optical path of the light beam output from the size discrimination sensor 32, the wafer holder 22 for 8 inches is located at a position that does not exist on this optical path. The size discrimination sensor 32 is arranged. For example, it can be arranged at a position outside the outline of the 8-inch wafer holder 22 and at a position inside the outline of the 12-inch wafer holder 22. With this arrangement, the size determination sensor 32 receives the reflected light reflected by the wafer holding unit 22 only in the case of the 12-inch wafer holding unit 22. Therefore, the size discrimination sensor 22 detects the 12-inch wafer holder 22 and does not detect the 8-inch wafer holder 22.

  In addition, the shape determination sensor 34 determines whether the shape of the wafer holding unit 22 mounted on the mounting unit 24 is a C-shape or a scoop type. Similar to the size discrimination sensor 32, the scoop type wafer holding unit 22 exists on the optical path of the light beam output from the shape discrimination sensor 34, and the C-shaped wafer holding unit 22 does not exist on this optical path. The shape discrimination sensor 34 is disposed at such a position. For example, the scoop type wafer holder 22 has a surface for holding the semiconductor wafer 50 at the center of the holding surface. On the other hand, the C-shaped wafer holder does not have a surface for holding the semiconductor wafer 50 at the center of the holding surface. By utilizing this difference in shape, the shape discrimination sensor 34 can be arranged in an area corresponding to the central portion of the holding surface on the position table 13. By arranging in this way, the reflected light reflected by the wafer holding unit 22 is received only when the shape of the wafer holding unit 22 is a scoop type. Therefore, the scoop type wafer holder 22 is detected, and the C-shaped wafer holder 22 is not detected.

  The four wafer holders 22a to 22d are discriminated based on the combination of the detection states of the size discrimination sensor 32 and the shape discrimination sensor 34 installed in this way. First, for the 12-inch C-shaped wafer holder 22a, as shown in FIG. 5A, the size discrimination sensor 32 detects a part of the wafer holder 22 on the optical path, and the shape discrimination sensor 34 holds the wafer. The part 22 is not detected. Therefore, it is determined that the mounted wafer holder 22 is a 12-inch C-shaped wafer holder 22a.

  Next, for the 8-inch C-shaped wafer holder 22b, as shown in FIG. 5B, the wafer holder 22 does not exist on the optical paths of the size discrimination sensor 32 and the shape discrimination sensor 34. Therefore, neither the discrimination sensors 32 and 34 detect the wafer holding unit 22. Therefore, it is determined that the mounted wafer holder 22 is an 8-inch C-shaped wafer holder 22b.

  Similarly, as for the 12 inch scoop type wafer holder 22c, as shown in FIG. 5C, a part of the wafer holder 22 exists on each optical path of the size discrimination sensor 32 and the shape discrimination sensor 34. Both 32 and 34 detect the wafer holding unit 22. Therefore, it is determined that the mounted wafer holder 22 is a 12 inch scoop type wafer holder 22c.

  As shown in FIG. 5D, for the 8-inch scoop type wafer holder 22d, the size discrimination sensor 32 does not detect the wafer holder 22, and the shape discrimination sensor 34 detects the wafer holder 22 on the optical path. To do. Therefore, it is determined that the mounted wafer holder 22 is an 8-inch scoop type wafer holder 22d.

  As described above, for example, a plurality of discrimination sensors such as the size discrimination sensor 32 and the shape discrimination sensor 34 are installed, and the type of the wafer holding unit 22 mounted can be discriminated by the combination thereof.

  Next, a procedure for determining the type of the wafer holding unit 22 in the above-described grinding apparatus 1 will be described with reference to FIG.

  First, the operator places the cassettes 11 and 12 containing the semiconductor wafers 50 to be processed on the grinding apparatus 1. Thereafter, the cassette discriminating means 10 discriminates the type of the loaded cassettes 11 and 12 (step S10). As described above, the method of discriminating the cassette by the cassette discriminating means 10 includes a method of identifying by reading an identification mark such as a barcode.

  Next, based on the types of the cassettes 11 and 12 determined by the cassette recognizing unit 10, the recognizing unit 15 recognizes the correct type of the wafer holding unit 22 (step S20). The correct wafer holding unit 22 to be mounted on the mounting unit 24 is recognized by the recognition unit 15. Then, the correct shape of the wafer holding unit 22 is stored in the storage unit 75.

  Further, the operator mounts the wafer holding unit 22 on the mounting unit 24 of the transport unit 20. After the mounting, the wafer holding unit 22 is moved to the determination area for determining the type of the mounted wafer holding unit 22 by the transfer means 20 (step S30).

  Thereafter, the type of the wafer holding unit 22 mounted on the mounting unit 24 is determined by the determination unit 30 (step S40). In step S40, as described above, the size determination sensor 32 and the shape determination sensor 34 detect the wafer holding unit 22 moved to the determination region. By combining the presence or absence of these detections, the type of the wafer holding unit 22 mounted on the mounting unit 24 is determined.

  Next, the comparison unit 70 compares the type of the wafer holding unit 22 determined by the determination unit 30 with the type of the wafer holding unit 22 recognized by the recognition unit 15 and determines whether or not both match. (Step S50). If they match, it is determined that the correct wafer holding unit 22 is mounted, and the operation of the grinding apparatus 1 is continued (step S90). If they do not match, it is determined that the wrong wafer holding unit 22 is mounted, and the operation of the grinding apparatus 1, at least the operation of the transfer means 20, is stopped (step S60).

  When the operation of at least the conveying means 20 of the grinding apparatus 1 is stopped, the correct type of the wafer holding unit 22 is displayed on the display unit 90 of the grinding apparatus 1 and the operator is urged to replace the wafer holding unit 22 (step S70). . Then, the operator mounts the correct wafer holding unit 22 displayed on the display unit 90 on the mounting unit 24 (step S80). Then, when it is detected that the operator has replaced the wafer holding unit 22 or when the operator inputs that the wafer holding unit 22 has been replaced, the wafer holding unit 22 is moved to the discrimination area for confirmation again. 22 types are discriminated (step S30 to step S50). Note that, after replacing the wafer holding unit 22 with the correct one, the type of the wafer holding unit 22 is determined again. However, the next processing may be performed as it is.

  By such a procedure, the wafer holding unit 22 recognized by the recognition unit 15 is compared with the wafer holding unit 22 discriminated by the discriminating unit 30, and whether the correct wafer holding unit 22 is mounted on the mounting unit 24. Can be confirmed. Thereby, it is possible to prevent erroneous mounting of the wafer holding unit 22 by the operator.

  A plurality of discrimination sensors such as the size discrimination sensor 32 and the shape discrimination sensor 34 can be installed by the discrimination means 30 as described above, and the type of the wafer holder 22 mounted can be discriminated by the combination thereof. An increase in the number of types of wafer holders 22 can be dealt with by increasing the number of discrimination sensors.

  Further, it is possible to determine the type of the wafer holding unit 22 mounted by moving the wafer holding unit 22 without adding a discrimination sensor.

  For example, even if the workpieces have the same size and have the same shape, the size of the wafer holding unit 22 needs to be changed for the reason described above. Specifically, consider a 12-inch scoop type wafer holder 22. Here, out of the 12-inch rice scoop type wafer holding unit 22, the larger one is referred to as a “scaffold large size 22e”, and the smaller one is referred to as a “scuffle small size 22f”. In this case, since both the size determination sensor 32 and the shape determination sensor 34 show the same detection state, it is not possible to determine both by the two determination sensors 32 and 34 alone.

  Therefore, a size discrimination method for discriminating between the large scoop 22e and the small scoop 22f will be described below with reference to FIGS. FIG. 7 is a flowchart illustrating a method for determining the type of the wafer holding unit 22 by moving the wafer holding unit 22. FIG. 8 is a diagram showing a state when the large scoop 22e and the small scoop 22f are at the measurement position in the discrimination region. FIG. 9 is a diagram showing a state where the presence / absence of detection of the shape determination sensor 34 is changed by moving the large scoop 22e and the small scoop 22f from the measurement position.

First, as shown in FIG. 7, for the scooping large size 22e and the scooping small size 22f, the linear distance from any edge of each wafer holding unit 22 to any reflective optical sensor in the discrimination region is stored (step S41). . Here, any reflection type optical sensor is referred to as a shape discrimination sensor 34. As shown in FIG. 8A and FIG. 8B, for example, an arbitrary edge of the large rice paddle 22e is an edge A, and an arbitrary edge of the small rice paddy 22f is an edge B. For the large rice paddy 22e, the linear distance D ₁ from the edge A to the shape determining sensor 34 and for the small rice pad 22f, the linear distance D ₂ from the edge B to the shape determining sensor 34 are stored in advance.

  Next, the wafer holding unit 22 is moved along a straight line connecting an arbitrary edge of each wafer holding unit 22 and the shape determination sensor 34 (step S43). As shown in FIGS. 9A and 9B, each wafer holding unit 22 is moved to the shape discrimination sensor 34 side along the straight line whose distance is measured in step S41.

Further, when the wafer holding unit 22 is moved to a position where it is no longer detected by the shape discrimination sensor 34, the wafer holding unit 22 is stopped and the moving distance d from the first measurement position is measured (step S45). At this time, each wafer holding part 22 exists in the position where the edge part A and the edge part B overlap with the shape discrimination | determination sensor 34, as shown to Fig.9 (a) and FIG.9 (b). Then, the distance moved to this position, that is, the movement distance d ₁ and the movement distance d ₂ are measured.

Thereafter, the distance (D ₁ , D ₂ ) stored in advance and the moving distance d measured in step S45 are compared to determine the type of the wafer holder 22 (step S47). For example, when the moving distance d of the wafer holder 22 is coincident with D _1, the wafer holding unit 22 it can determine the ladle large 22e. Similarly, when the moving distance d of the wafer holding portion 22 coincides with D _2, the wafer holding unit 22 can determine the paddle size 22f.

  As described above, the size of the wafer holding unit 22 that cannot be determined only by the discrimination sensor by moving the wafer holding unit 22 without adding a new discrimination sensor in addition to the size discrimination sensor 32 and the shape discrimination sensor 34. Can be determined.

  As described above, it is possible to confirm that the appropriate type of wafer holding unit 22 is always mounted by the grinding apparatus 1 according to the present embodiment. Thereby, it is possible to prevent the wafer holding unit 22 and the semiconductor wafer 50 from being damaged by detecting erroneous mounting of the wafer holding unit 22 by the operator and stopping the moving means 20 of the grinding apparatus 1. Moreover, since the determination means 30 is not provided in the conveyance means 20, the factor by which the conveyance means 20 fails can be reduced. Further, when the number of types of the wafer holding units 22 increases, it is possible to easily cope with this by increasing the number of discriminating means 30, but it is possible to specify each wafer holding unit without installing a new discriminating means. By storing the distance in advance, the type can be determined based on the stored distance.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the present embodiment, the shape of the wafer holding unit 20 has been described with respect to the C-shape and the scoop type. However, the present invention is not limited to this example, and may be a U-shape. In addition, in this embodiment, the size of the wafer holding unit 20 corresponds to the size of the semiconductor wafer 50 of 8 inches and 12 inches. However, the size is not limited to this example, and corresponds to the semiconductor wafer 50 of 6 inches, for example. It is also possible to provide a wafer holding unit 20 to be used.

  In the grinding apparatus 1 according to the present embodiment, the determination area is set as the alignment means. However, the present invention is not limited to this example, and a separate area may be provided for the grinding apparatus 1.

  Further, in the grinding apparatus 1 according to the present embodiment, the correct wafer holding unit 22 to be mounted on the mounting unit 24 is automatically recognized by the recognition unit 15 based on the determined information on the types of the cassettes 11 and 12. . However, the present invention is not limited to this example, and may be recognized by an operator input, for example.

  In the present embodiment, a reflective optical sensor is used as the discriminating means 30. However, the present invention is not limited to such an example, and the presence of the workpiece holder 22 may be detected using, for example, a contact sensor. . However, a non-contact type sensor such as a reflective optical sensor has an advantage that there is no damage due to contact because it does not contact the workpiece holder 22.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a grinding apparatus and a workpiece holding unit size determination method, and in particular, a grinding apparatus capable of selectively mounting a plurality of workpiece holding units and a workpiece holding unit size determination method. It is applicable to.

1 is an overall perspective view showing a grinding apparatus according to a first embodiment of the present invention. It is explanatory drawing which showed the conveying means concerning this embodiment. It is the block diagram which showed the component for discriminating the kind of wafer holding part in the grinding apparatus concerning this embodiment. It is explanatory drawing which showed the discrimination | determination means concerning this embodiment. It is the figure which showed the state where the 12-inch C-shaped pick was put in the discrimination area. It is the figure which showed the state where the 8-inch C-shaped pick was put in the discrimination area. It is the figure which showed the state where the 12 inch scoop type pick was placed in the discrimination area. It is the figure which showed the state where the 8-inch scoop type pick was placed in the discrimination area. It is the flowchart which showed the method of discriminating the kind of wafer holding part concerning this embodiment. It is the flowchart which showed the method of discriminating the kind of wafer holding part by moving a wafer holding part. It is explanatory drawing which shows the state in which the workpiece holding part was put in the measurement position of a discrimination | determination area | region, (a) shows the state in which the large size of scoop is put in the discrimination area, (b) is discriminate | determined that the small size of scoop It shows the state placed in the area. It is explanatory drawing which shows a state when the workpiece holding part is moved from a measurement position and the detection state of the shape discrimination sensor changes. The mounted workpiece holding part is (a) a large scoop. A certain time is shown, and (b) shows a time when the paddle is small.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Grinding device 10 Cassette discriminating means 11, 12 Cassette 13 Position table 15 Recognizing means 20 Conveying means 22 Wafer holding part (workpiece holding part)
24 mounting portion 26 moving portion 30 discrimination means 32 size discrimination sensor 34 shape discrimination sensor 50 semiconductor wafer 60 control means 70 display portion

Claims (1)

A plurality of types of workpiece holding units for holding a workpiece, a mounting unit for selectively mounting the plurality of types of workpiece holding units, and a movement for moving the workpiece holding unit and the mounting unit. A grinding device provided with a conveying means comprising a part,
Recognizing means for recognizing a correct type of workpiece holding unit corresponding to at least one of the type of workpiece or the conveyance method of the workpiece among the plurality of types of workpiece holding units;
Size discriminating means for discriminating the size of the workpiece holding part mounted on the mounting part, and shape discriminating means for discriminating the shape of the workpiece holding part mounted on the mounting part, The size discriminating means and the shape discriminating means are installed at a position corresponding to the size or shape of the workpiece holding portion, and when the workpiece holding portion mounted on the mounting portion is arranged in the discrimination area, A discriminating unit for discriminating the type of the workpiece holding unit mounted on the mounting unit based on the detection results of the size determining unit and the shape determining unit;
If the type of the workpiece holding unit recognized by the recognition unit is different from the type of the workpiece holding unit mounted on the mounting unit determined by the determination unit, stop at least the transport unit Control means,
A grinding apparatus comprising:

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