Transport Pallets

Abstract

The present invention provides a conveying tray that can stably hold an ingot when conveying it and prevent the ingot from falling off. The conveying tray includes a shell, an ingot storage recess for storing semiconductor ingots, and a wafer storage recess for storing wafers. The shell has an upper wall, a lower wall, a pair of side walls connecting the upper wall and the lower wall, and a tunnel formed by the upper wall, the lower wall, and the pair of side walls. In the shell, a plurality of levers are mounted so as to be rotatable around a fulcrum, and the plurality of levers respectively have a force point protruding from the bottom surface of the ingot storage recess, an action point protruding from the side surface of the ingot storage recess, and the fulcrum formed between the force point and the action point.

Description

Technical Field

[0001] The present invention relates to a transfer tray used in a wafer production apparatus for producing wafers from a semiconductor ingot. Background Art

[0002] Devices such as ICs, LSIs, and LEDs are formed by stacking functional layers on the front of a wafer made of materials such as Si (silicon) or Al2O3 (sapphire), and then dividing the functional layers along a plurality of intersecting dividing lines. Furthermore, power devices and LEDs are formed by stacking functional layers on the front of a wafer made of single-crystal SiC (silicon carbide), and then dividing the functional layers along a plurality of intersecting dividing lines. The wafers with the devices formed on them are then processed along the dividing lines by cutting equipment or laser processing equipment to separate them into individual device chips. The resulting device chips are then used in electronic devices such as mobile phones and personal computers.

[0003] The wafers that form the devices are generally produced by cutting a cylindrical ingot into a thinner shape using a wire saw. The front and back of the cut wafers are polished to a mirror finish (for example, see Patent Document 1). However, when the ingot is cut using a wire saw and the front and back of the cut wafers are polished, most of the ingot (70-80%) is discarded, which is uneconomical. In particular, single-crystal SiC ingots are difficult to cut using a wire saw due to their high hardness, which requires a considerable amount of time, resulting in poor productivity. In addition, due to the high unit price of the ingot, there is a problem of efficiently producing wafers.

[0004] Therefore, the following technology has been proposed: the focal point of a laser beam having a wavelength that is transmissive to single-crystalline SiC is positioned inside a single-crystalline SiC ingot, and the single-crystalline SiC ingot is irradiated with the laser beam to form a peeling layer on the predetermined cutting surface, and the chip is peeled from the single-crystalline SiC ingot along the predetermined cutting surface on which the peeling layer is formed (for example, refer to Patent Document 2).

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2000-94221

[0006] Patent Document 2: Japanese Patent Application Publication No. 2019-106458

[0007] In the wafer production apparatus disclosed in Patent Document 2, an ingot and peeled wafers are placed on a transport tray and transported between units such as an ingot grinding unit and a laser irradiation unit. However, when the ingot is supported by an ingot support portion of the transport tray and transported, the ingot is unstable relative to the transport tray, and there is a risk that the ingot may fall off the transport tray. Summary of the Invention

[0008] Therefore, an object of the present invention is to provide a transport tray that can stably hold an ingot and prevent the ingot from falling off when the ingot is transported.

[0009] According to the present invention, a conveying tray is provided, which is used in a chip generating device for generating chips from semiconductor ingots, wherein the conveying tray comprises: a shell including an upper wall, a lower wall, a pair of side walls connecting the upper wall and the lower wall, and a tunnel formed by the upper wall, the lower wall and the pair of side walls; an ingot storage recess formed in the upper wall of the shell for storing the semiconductor ingot; a chip storage recess formed in the lower wall of the shell for storing the chip; and a plurality of levers, each of the plurality of levers having a force point protruding from the bottom surface of the ingot storage recess, an action point protruding from the side surface of the ingot storage recess, and a fulcrum formed between the force point and the action point, and the plurality of levers are mounted on the shell in a manner capable of rotating around the fulcrum, and when the semiconductor ingot is stored in the ingot storage recess, the force point of each lever is moved due to the weight of the semiconductor ingot, and the side surface of the semiconductor ingot is supported by the action point of each lever.

[0010] The ingot housing recess preferably includes a plurality of concentric housing recesses corresponding to semiconductor ingots of different sizes.

[0011] According to the present invention, the weight of the ingot causes the force point to move, thereby supporting the side surface of the ingot by the action point. Therefore, when the ingot is transported, the ingot can be stably held and the ingot can be prevented from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view of a transport pallet according to an embodiment of the present invention.

[0013] Figure 2 yes Figure 1 Front view of the lever shown.

[0014] Figure 3 (a) is a state where the large diameter ingot is positioned above the ingot storage recess. Figure 1 The cross-sectional view of the transport pallet shown, Figure 3 (b) shows a state where a large diameter ingot is supported in an ingot receiving recess. Figure 1 A cross-sectional view of the transport pallet shown.

[0015] Figure 4 (a) is a state where a small diameter ingot is positioned above the ingot storage recess. Figure 1 The cross-sectional view of the transport pallet shown, Figure 4 (b) is a state where a small diameter ingot is supported in an ingot receiving recess. Figure 1 A cross-sectional view of the transport pallet shown.

[0016] Figure 5 It is a front view showing a modified example of the lever.

[0017] Figure 6 is used Figure 1 A perspective view of a wafer production device with a transfer tray shown.

[0018] Figure 7 yes Figure 6 A partial perspective view of a wafer production apparatus is shown.

[0019] Description of labels

[0020] 2: Conveyor tray; 4: Shell; 6: Ingot storage recess; 6a: First ingot storage recess; 6b: Second ingot storage recess; 8: Wafer storage section; 8a: First wafer storage section; 8b: Second wafer storage section; 10: Upper wall; 12: Lower wall; 14: Side wall; 16: Tunnel; 22: Lever; 22a: First part of the lever; 22b: Second part of the lever; 22c: Third part of the lever; 22d: Fourth part of the lever; 22e: Fifth part of the lever; 22f: Sixth part of the lever; 24: Force point; 24a: First force point; 24b: Second force point; 26: Action point; 26a: First action point; 26b: Second action point; 28: Fulcrum. DETAILED DESCRIPTION

[0021] Hereinafter, a conveyance pallet according to a preferred embodiment of the present invention will be described with reference to the drawings.

[0022] exist Figure 1 The transfer tray, which is generally indicated by reference numeral 2, includes a housing 4, an ingot storage recess 6 for storing semiconductor ingots (hereinafter referred to simply as ingots), and a wafer storage portion 8 for storing wafers.

[0023] The housing 4 includes a rectangular upper wall 10 , a rectangular lower wall 12 disposed below the upper wall 10 , a pair of rectangular side walls 14 connecting the upper wall 10 and the lower wall 12 , and a tunnel 16 formed by the upper wall 10 , the lower wall 12 , and the pair of side walls 14 .

[0024] like Figure 1 As shown, the ingot storage recess 6 is formed on the upper surface of the upper wall 10 of the housing 4. The ingot storage recess 6 of this embodiment includes an annular first ingot storage recess 6a, which is recessed downward from the upper surface of the upper wall 10; and a circular second ingot storage recess 6b, which has a smaller diameter than the first ingot storage recess 6a and is recessed further downward than the first ingot storage recess 6a. The first ingot storage recess 6a and the second ingot storage recess 6b are formed concentrically.

[0025] The diameter of the first ingot storage recess 6a is slightly larger (by several mm) than a cylindrical ingot 18 with a relatively large diameter (e.g., a 6-inch diameter), and the first ingot storage recess 6a stores the relatively large diameter ingot 18. The diameter of the second ingot storage recess 6b is slightly larger than a cylindrical ingot 20 with a relatively small diameter (e.g., a 4-inch diameter), and the second ingot storage recess 6b stores the relatively small diameter ingot 20.

[0026] Thus, the ingot storage recess 6 of this embodiment includes concentric first and second ingot storage recesses 6a and 6b corresponding to the two sizes of ingots 18 and 20. Furthermore, the ingot storage recess 6 may include a single circular storage recess corresponding to one size of ingot, or may include a plurality of concentric storage recesses corresponding to three or more sizes of ingots.

[0027] When referring to Figures 1 to 3 For purposes of illustration, a plurality (four in this embodiment) of levers 22 are provided on the transport tray 2 at intervals along the circumference of the ingot storage recess 6. Each lever 22 has a force point 24 protruding from the bottom surface of the ingot storage recess 6, an action point 26 protruding from the side surface of the ingot storage recess 6, and a fulcrum 28 formed between the force point 24 and the action point 26.

[0028] By reference Figure 3 As can be seen, each lever 22 is disposed in a receiving hole 30 formed in the housing 4 corresponding to the shape of the lever 22 , and is swingably supported by the housing 4 via a pin (reference numeral omitted) penetrating a fulcrum 28 .

[0029] like Figure 2 and Figure 3 As shown, the lever 22 of this embodiment has: a first part 22a, which extends upward from the fulcrum 28; a second part 22b, which extends from the upper end of the first part 22a to the radial inner side of the ingot receiving recess 6; a third part 22c, which extends from the fulcrum 28 to the radial inner side of the ingot receiving recess 6; a fourth part 22d, which extends upward from the third part 22c between the radial outer end and the radial inner end of the third part 22c; a fifth part 22e, which extends radially inward from the fourth part 22d between the upper end and the lower end of the fourth part 22d; and a sixth part 22f, which extends upward from the radial inner end of the third part 22c.

[0030] The lever 22 of this embodiment has a force point 24 comprising a first force point 24a, which is formed by the upper end of the fourth portion 22d protruding from the bottom surface of the first ingot storage recess 6a; and a second force point 24b, which is formed by the upper end of the sixth portion 22f protruding from the bottom surface of the second ingot storage recess 6b. The lever 22 of this embodiment has a first force point 26a, which is formed by the radially inner end of the second portion 22b protruding (capable of protruding) from the side surface of the first ingot storage recess 6a; and a second force point 26b, which is formed by the radially inner end of the fifth portion 22e protruding (capable of protruding) from the side surface of the second ingot storage recess 6b.

[0031] The lever 22 is able to swing freely about the fulcrum 28 between a supporting position where the side of the ingot is supported by the action point 26 and a release position where the support of the ingot is released. Figure 3 As shown in (a), in the release position, the first force point 24a protrudes from the bottom surface of the first ingot storage recess 6a, and the second force point 24b protrudes from the bottom surface of the second ingot storage recess 6b. On the other hand, the first action point 26a does not protrude from the side surface of the first ingot storage recess 6a, and the second action point 26b does not protrude from the side surface of the second ingot storage recess 6b.

[0032] like Figure 3 As shown in FIG. 2 (a), in the conveying tray 2 of this embodiment, a positioning unit 32 is attached to the housing 4 for positioning the lever 22 in the released position when the ingots 18 and 20 are not accommodated in the first and second ingot accommodation recesses 6a and 6b. The positioning unit 32 of this embodiment is composed of a coil spring disposed in a radially extending hole 34 formed in the housing 4. One end of the coil spring is connected to the first portion 22a of the lever 22, and the other end of the coil spring is connected to the side surface of the hole 34.

[0033] When referring to Figure 3 Continuing the description, when the large diameter ingot 18 is accommodated in the first ingot accommodation recess 6a, as shown in FIG. Figure 3 As shown in (b), the first force point 24a of the lever 22 is pushed by the ingot 18 and moves downward. That is, the first force point 24a is actuated by the deadweight of the ingot 18. Then, the lever 22 overcomes the force of the positioning unit 32 and swings toward the supporting position with the fulcrum 28 as the center, and the first action point 26a of the lever 22 protrudes from the side of the first ingot storage recess 6a to support the side of the ingot 18. Therefore, in the conveying tray 2, when the ingot 18 is conveyed, the ingot 18 can be stably held and can be prevented from falling off. In addition, the number of levers 22 is arbitrary, but from the viewpoint of stably holding the ingot 18, 3 or more are preferably used.

[0034] Reference Figure 4 (a) and Figure 4(b) is used to illustrate that when the small diameter ingot 20 is accommodated in the second ingot accommodation recess 6b, as shown in FIG. Figure 4 As shown in (b), the weight of the ingot 20 causes the second force point 24b to actuate (move downward). Consequently, the lever 22 overcomes the force of the positioning unit 32 and swings toward the supporting position about the fulcrum 28. The second action point 26b of the lever 22 protrudes from the side of the second ingot storage recess 6b, supporting the side of the ingot 20. Thus, the transport tray 2 is equipped with levers 22 corresponding to the size of the ingots 18 and 20, enabling the ingots 18 and 20 to be stably held.

[0035] On the other hand, when the ingots 18 and 20 are removed from the first and second ingot storage recesses 6a and 6b, the weight of the ingots 18 and 20 no longer acts on the first and second force points 24a and 24b. Therefore, the lever 22 is swung toward the release position with the fulcrum 28 as the center through the positioning unit 32.

[0036] In addition, the positioning means 32 for biasing the lever 22 toward the released position is formed of a coil spring in this embodiment. However, any method is not limited to a coil spring as long as the lever 22 is allowed to swing when the ingots 18 and 20 are housed in the first and second ingot housing recesses 6a and 6b and the lever 22 is biased toward the released position to such an extent that the first and second points of application 26a and 26b can support the side surfaces of the ingots 18 and 20. The positioning means 32 may be made of metal, synthetic rubber, synthetic resin, or the like.

[0037] Furthermore, the positioning unit 32 may not be attached to the housing 4 by appropriately adjusting the center of gravity position of the lever 22 and the position of the fulcrum 28 so that the lever 22 is located at the release position when the ingots 18 and 20 are not accommodated in the first and second ingot accommodation recesses 6a and 6b.

[0038] The lever 22 corresponds to the size of the ingots 18 and 20, but may also be Figure 5 As shown, a plurality of first levers 36 a corresponding to the ingot 18 and a plurality of second levers 36 b corresponding to the size of the ingot 20 are arranged in the housing 4 at intervals in the circumferential direction.

[0039] Moreover, although not shown in the figure, it is also possible that when the ingot 18 is accommodated in the first ingot accommodation recess 6a, the first force point 38a is moved by the own weight of the ingot 18 (the first lever 36a swings around the first fulcrum 40a) so that the first action point 42a supports the side of the ingot 18, and when the ingot 20 is accommodated in the second ingot accommodation recess 6b, the second force point 38b is moved by the own weight of the ingot 20 (the second lever 36b swings around the second fulcrum 40b) so that the second action point 42b supports the side of the ingot 20.

[0040] Furthermore, in a case where the ingot storage recess 6 is a single circular storage recess corresponding to one size of ingot, a lever corresponding to one size of ingot is provided; and in a case where the ingot storage recess 6 has concentric storage recesses corresponding to three or more sizes of ingots, levers corresponding to three or more sizes of ingots are provided.

[0041] like Figure 1 As shown, the wafer storage portion 8 is formed on the upper surface of the lower wall 12 of the housing 4. The wafer storage portion 8 of this embodiment includes an annular first wafer storage portion 8a that is recessed downward from the upper surface of the lower wall 12, and a circular second wafer storage portion 8b that is smaller in diameter than the first wafer storage portion 8a and recessed further downward than the first wafer storage portion 8a. The first wafer storage portion 8a and the second wafer storage portion 8b are formed concentrically.

[0042] The diameter of the first wafer storage section 8a is slightly larger than that of a disk-shaped wafer with a relatively large diameter (e.g., a 6-inch diameter), and the first wafer storage section 8a stores the relatively large wafers. The diameter of the second wafer storage section 8b is slightly larger than that of a disk-shaped wafer with a relatively small diameter (e.g., a 4-inch diameter), and the second wafer storage section 8b stores the relatively small wafers.

[0043] Thus, the wafer storage section 8 of this embodiment has concentric first and second wafer storage sections 8a and 8b corresponding to two sizes of wafers. Alternatively, the wafer storage section 8 may have a single circular storage section corresponding to one size of wafers, or may have a plurality of concentric storage sections corresponding to three or more sizes of wafers.

[0044] exist Figure 6 and Figure 7 2 shows a wafer production apparatus 50 using the above-described transfer tray 2 .

[0045] The chip generating device 50 for generating chips from an ingot comprises: an ingot grinding unit 52; a laser irradiation unit 54; a chip peeling unit 56; a belt conveyor unit 58, which transports the ingot supported by the above-mentioned conveying tray 2 between the ingot grinding unit 52, the laser irradiation unit 54 and the chip peeling unit 56; a conveying tray storage bin 60; a box storage bin 64, which stores a plurality of boxes 62, each of which stores chips peeled from the ingot; and a storage unit 66, which transports the conveying tray 2 in the conveying tray storage bin 60 to the belt conveyor unit 58, and stores the chips supported by the chip storage portion 8 of the conveying tray 2 in the box 62 in the box storage bin 64.

[0046] like Figure 7As shown, the ingot grinding unit 52 includes a rotatable holding table 68 that holds the ingot by suction, and a grinding unit 70 that grinds the upper surface of the ingot held by suction on the holding table 68 to flatten the ingot's upper surface. The grinding unit 70 includes a rotatable grinding wheel 72 having a grinding tool (not shown). The ingot grinding unit 52 grinds the upper surface of the ingot by rotating the holding table 68 that holds the ingot by suction and the grinding wheel 72, thereby bringing the grinding tool into contact with the upper surface of the ingot and flattening the ingot's upper surface.

[0047] The laser irradiation unit 54 includes a holding table 74 that holds the ingot by suction and is movable and rotatable in the X-axis direction, and a laser irradiation unit 76 that irradiates the ingot held by suction on the holding table 74 with laser light. The laser irradiation unit 76 includes a condenser 78 that condenses pulsed laser light emitted from a laser oscillator (not shown) to irradiate the ingot, and is movable in the Y-axis direction.

[0048] The laser irradiation unit 54 moves the holding workbench 74 that attracts and holds the ingot in the X-axis direction or moves the condenser 78 in the Y-axis direction, while positioning the focal point of the laser light of a wavelength that is transparent to the ingot at a depth equivalent to the thickness of the wafer to be generated from the upper surface of the ingot and irradiating the ingot with the laser light, thereby forming a peeling layer with reduced strength inside the ingot.

[0049] The chip peeling unit 56 includes: a holding workbench 80, which attracts and holds the ingot and is movable in the X-axis direction; a liquid tank body 82, which cooperates with the holding workbench 80 to form a liquid storage space; and an ultrasonic vibration generating component 84, which imparts ultrasonic vibration to the ingot attracted and held on the holding workbench 80 and attracts and holds the chip peeled from the ingot.

[0050] After the wafer peeling unit 56 stores liquid in the liquid storage space formed by the holding table 80 holding the ingot by suction and the liquid tank 82 , it operates the ultrasonic vibration generating member 84 to apply ultrasonic vibration to the ingot, thereby peeling the wafer from the ingot starting from the peeling layer.

[0051] The belt conveyor unit 58 includes: an outgoing belt conveyor 86, which conveys the conveying pallet 2 along the Y1 direction; a return belt conveyor 88, which conveys the conveying pallet 2 along the Y2 direction (the opposite direction of Y1); a first conveying unit 90, which conveys the conveying pallet 2 from the end point of the outgoing belt conveyor 86 to the starting point of the return belt conveyor 88, and stops the conveying pallet 2 conveyed by the outgoing belt conveyor 86 at a position opposite to the chip peeling unit 56; and a second conveying unit 92, which conveys the conveying pallet 2 from the end point of the return belt conveyor 88 to the starting point of the outgoing belt conveyor 86.

[0052] In addition, the belt conveyor unit 58 includes: a first conveying pallet stopper 94 that can be raised and lowered, which stops the conveying pallet 2 conveyed by the outgoing belt conveyor 86 at a position opposite to the ingot grinding unit 52; and a second conveying pallet stopper 96 that can be raised and lowered, which stops the conveying pallet 2 conveyed by the outgoing belt conveyor 86 at a position opposite to the laser irradiation unit 54.

[0053] In addition, the conveyor unit 58 also includes: a first transfer unit 98, which transfers the ingot between the conveying pallet 2 stopped by the first conveying pallet stopper 94 and the ingot grinding unit 52; a second transfer unit 100, which transfers the ingot between the conveying pallet 2 stopped by the second conveying pallet stopper 96 and the laser irradiation unit 54; and a third transfer unit 102, which transfers the ingot between the conveying pallet 2 stopped by the first conveying unit 90 and the chip peeling unit 56, and transfers the chip peeled from the ingot from the chip peeling unit 56 to the conveying pallet 2.

[0054] The first, second, and third transfer units 98, 100, and 102, which may each have a common structure, each include a multi-jointed arm 104 that can move in the X-axis, Y-axis, and Z-axis directions, and a suction sheet 106 that is mounted on the front end of the multi-jointed arm 104 so that it can be freely rotated up and down. A plurality of suction holes (not shown) connected to a suction unit (not shown) are formed on one surface of the suction sheet 106.

[0055] When referring to Figure 6 In the description, the transport tray storage bin 60 of this embodiment has four storage sections 108 that penetrate along the X-axis direction. In the transport tray storage bin 60, the transport tray 2 can be stored in the storage bin. Figure 6 The transport tray 2 in the storage section 108 is stored in the storage section 108 from the front side in the X-axis direction, and the transport tray 2 in the storage section 108 is stored in the storage section 108. Figure 6 Move it out from the inner side in the X-axis direction.

[0056] like Figure 6As shown, the cassette storage bin 64 of this embodiment has 16 storage sections 110 extending through the Y-axis direction, and each storage section 110 stores a cassette 62 for storing wafers peeled from an ingot. Figure 6 The wafer is stored in the storage portion 110 from the front side in the Y-axis direction, and the wafer can be stored in the storage portion 110. Figure 6 The cartridge 62 is housed in the housing portion 110 from the inner side in the Y-axis direction.

[0057] like Figure 7 As shown, the storage unit 66 includes a multi-jointed arm 112 that can move in the X-axis, Y-axis, and Z-axis directions, and a suction sheet 114 that is mounted on the front end of the multi-jointed arm 112 so as to be freely reversible up and down. A plurality of suction holes (not shown) connected to a suction unit (not shown) are formed on one surface of the suction sheet 114.

[0058] When wafers are produced from an ingot by the wafer production apparatus 50, as shown in FIG. Figure 6 As shown, first, one or more ingots (in this embodiment, four large-diameter ingots 18) are prepared. Next, to prevent the ingots 18 from falling off the conveying tray 2 during transport within the wafer production apparatus 50, each ingot 18 is stored in the first ingot storage recess 6a of the conveying tray 2, with the side surfaces of the ingots 18 supported by the first action points 26a. The conveying tray 2 supporting the ingots 18 is then stored in the storage section 108 of the conveying tray storage bin 60.

[0059] Next, the following first transport step is performed: the ingot 18 is transported from the transport tray storage bin 60 to the laser irradiation unit 54. Typically, the end surface of the ingot is flattened to a degree that does not hinder the incidence of laser light in the peeling layer forming step described later. Therefore, in this embodiment, an example in which the ingot 18 is transported from the transport tray storage bin 60 to the laser irradiation unit 54 in the first transport step is described. However, even if the end surface of the ingot 18 is not flattened to a degree that does not hinder the incidence of laser light in the peeling layer forming step, the ingot 18 may be transported from the transport tray storage bin 60 to the ingot grinding unit 52 in the first transport step.

[0060] In the first transport process, the multi-jointed arm 112 of the storage unit 66 is first driven to insert the suction sheet 114, with its suction holes facing upward, into the tunnel 16 of the transport pallet 2. Next, the suction sheet 114 is slightly raised within the tunnel 16, so that the suction sheet 114 attracts and holds the lower surface of the upper wall 10 of the transport pallet 2. The transport pallet 2, attracted and held by the suction sheet 114, is then transported from the transport pallet storage bin 60 to the outbound belt conveyor 86.

[0061] After the transport tray 2 is placed on the outgoing belt conveyor 86, the transport tray 2 is transported along the Y1 direction to a position opposite the laser irradiation unit 54 by the outgoing belt conveyor 86. At this time, the first transport tray stopper 94 is lowered and the second transport tray stopper 96 is raised, thereby stopping the transport tray 2 at a position opposite the laser irradiation unit 54.

[0062] Next, the multi-jointed arm 104 of the second transfer unit 100 is driven to attract and hold the ingot 18 on the conveying tray 2 using the suction sheet 106. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the conveying tray 2 to the holding table 74 of the laser irradiation unit 54. Furthermore, when the ingot 18 is lifted from the first ingot storage recess 6a, the weight of the ingot 18 no longer acts on the first force point 24a. Therefore, the lever 22 swings toward the release position about the fulcrum 28 via the positioning unit 32.

[0063] After the first conveying process is implemented, the following peeling layer forming process is implemented in the laser irradiation unit 54: the ingot 18 is attracted and held by the holding workbench 74, and the focal point of the laser light with a wavelength that is transparent to the ingot 18 is positioned at a depth equivalent to the thickness of the chip to be generated from the upper surface of the ingot 18 attracted and held by the holding workbench 74, and the laser light is irradiated on the ingot 18 to form a peeling layer.

[0064] After the separation layer forming step is performed, a second transporting step is performed in which the ingot 18 on which the separation layer is formed is transported from the laser irradiation unit 54 to the wafer separation unit 56 .

[0065] In the second transfer process, the multi-jointed arm 104 of the second transfer unit 100 is first driven to attract and hold the ingot 18 on the holding table 74 using the suction sheet 106. The suction of the holding table 74 is then released. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the holding table 74 to the first ingot storage recess 6a of the transfer tray 2.

[0066] Next, the transport tray 2 is transported along the Y1 direction by the outward belt conveyor 86 to a position opposite the wafer peeling unit 56. At this point, the transport tray 2 is stopped by the first transport unit 90 at a position opposite the wafer peeling unit 56. Next, the multi-jointed arm 104 of the third transfer unit 102 is driven to attract and hold the ingot 18 on the transport tray 2 using the suction sheet 106. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the transport tray 2 to the holding table 80 of the wafer peeling unit 56.

[0067] After the second conveying process is implemented, the following chip peeling process is implemented in the chip peeling unit 56: the ingot 18 with the peeling layer formed is sucked and held by the holding workbench 80, and the upper surface of the ingot 18 sucked and held by the holding workbench 80 is held to peel the chip from the ingot 18 starting from the peeling layer.

[0068] After the chip peeling process is implemented, the following third conveying process is implemented: the chip peeled from the ingot 18 (not shown) is conveyed from the chip peeling unit 56 to the box 62 of the box storage bin 64, and the ingot 18 after the chip is peeled is conveyed from the chip peeling unit 56 to the ingot grinding unit 52.

[0069] In the third transfer step, the multi-jointed arm 104 of the third transfer unit 102 is first driven to attract and hold the wafer separated from the ingot 18 using the suction sheet 106. The wafer attracted and held by the suction sheet 106 is then transferred from the wafer separation unit 56 to the first wafer storage section 8a of the transfer tray 2.

[0070] Next, the multi-jointed arm 104 of the third transfer unit 102 is driven to attract and hold the ingot 18 on the holding table 80 using the suction sheet 106, and then the suction of the holding table 80 is released. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the holding table 80 to the first ingot storage recess 6a of the transfer tray 2.

[0071] Next, the first transfer unit 90 transfers the transfer tray 2 supporting the ingot 18 and wafers from the outbound belt conveyor 86 to the return belt conveyor 88. The return belt conveyor 88 then transfers the transfer tray 2 in the Y2 direction and hands it over to the second transfer unit 92. The second transfer unit 92 then transfers the transfer tray 2 toward the outbound belt conveyor 86.

[0072] Before the transfer tray 2 is transferred from the second transfer unit 92 to the belt conveyor 86, the second transfer unit 92 is temporarily stopped. Next, the multi-jointed arm 112 of the storage unit 66 is driven to attract and hold the wafers supported by the transfer tray 2 on the second transfer unit 92 using the suction sheet 114. The wafers attracted and held by the suction sheet 114 are then removed from the transfer tray 2 and stored in the cassette 62 of the cassette storage bin 64.

[0073] Next, the second transport unit 92 is activated, and after the transport tray 2 is transferred from the second transport unit 92 to the outbound belt conveyor 86, the outbound belt conveyor 86 transports the transport tray 2 along the Y1 direction to a position opposite the ingot grinding unit 52. At this time, the first transport tray stopper 94 is raised, causing the transport tray 2 to stop at a position opposite the ingot grinding unit 52. Next, the multi-jointed arm 104 of the first transfer unit 98 is driven, and the ingot 18 on the transport tray 2 is attracted and held by the suction sheet 106. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the transport tray 2 to the holding table 68 of the ingot grinding unit 52.

[0074] After the third conveying process is implemented, the following ingot grinding process is implemented in the ingot grinding unit 52: the ingot 18 after the chip is peeled off is sucked and held by the holding workbench 68, and the upper surface (peeling surface) of the ingot 18 sucked and held by the holding workbench 68 is ground to flatten the upper surface of the ingot 18.

[0075] After the ingot grinding step is performed, a fourth transport step is performed in which the ingot 18 , the upper surface of which has been flattened, is transported from the ingot grinding unit 52 to the laser irradiation unit 54 .

[0076] In the fourth transfer step, the multi-jointed arm 104 of the first transfer unit 98 is first driven to attract and hold the ingot 18 on the holding table 68 using the suction sheet 106. The suction of the holding table 68 is then released. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the holding table 68 to the first ingot storage recess 6a of the transfer tray 2.

[0077] Next, the conveyor tray 2 is transported along the Y1 direction to a position opposite the laser irradiation unit 54 by the outward belt conveyor 86. Next, the multi-jointed arm 104 of the second transfer unit 100 is driven to attract and hold the ingot 18 on the conveyor tray 2 using the suction sheet 106. The ingot 18, attracted and held by the suction sheet 106, is then transferred from the conveyor tray 2 to the holding table 74 of the laser irradiation unit 54.

[0078] After the fourth transport step is performed, the above-described peeling layer forming step is performed in the laser irradiation unit 54. Furthermore, by repeating the peeling layer forming step, the wafer peeling step, the ingot grinding step, and the second to fourth transport steps, a sufficient number of wafers to be produced from the ingot 18 are generated and stored in the cassette 62 of the cassette storage bin 64.

[0079] In this embodiment, each process performed by the chip generating device 50 is described with a focus on one ingot 18, but after performing the first conveying process of conveying the ingot 18 from the conveying tray storage bin 60 to the laser irradiation unit 54, the first conveying process can be repeatedly performed at appropriate intervals, and the peeling layer forming process, the chip peeling process, the ingot grinding process and the second to fourth conveying processes can be repeatedly performed on multiple (for example, 4) ingots 18 in parallel, thereby generating a number of chips that can be generated from multiple ingots 18.

[0080] As described above, the conveying tray 2 of this embodiment used in the above-mentioned chip generating device 50 causes the force point 24 to move (move downward) by the weight of the ingot so that the action point 26 supports the side of the ingot. Therefore, when the ingot is conveyed, the ingot can be stably held and the ingot can be prevented from falling off.

Claims

1. A transport tray used in a wafer production device for producing wafers from semiconductor ingots, wherein: The transport pallet has: A housing comprising an upper wall, a lower wall, a pair of side walls connecting the upper wall and the lower wall, and a tunnel formed by the upper wall, the lower wall, and the pair of side walls; an ingot receiving recess formed on the upper wall of the housing for receiving the semiconductor ingot; as well as a wafer receiving recess formed on the lower wall of the housing for receiving wafers; The ingot storage recess has concentric storage recesses corresponding to two or more sizes of semiconductor ingots, and levers corresponding to the sizes of the two or more semiconductor ingots are arranged in the storage recesses. The lever has two or more force points protruding from the bottom surface of the ingot storage recess and corresponding to two or more sizes of semiconductor ingots, two or more application points protruding from the side surface of the ingot storage recess and corresponding to the two or more sizes of semiconductor ingots, and a common fulcrum connecting the two or more force points and the two or more application points. When the semiconductor ingot is accommodated in the ingot accommodation recess, the force point moves due to the weight of the semiconductor ingot accommodated in the ingot accommodation recess, thereby supporting the side of the semiconductor ingot through the action point corresponding to the size of the semiconductor ingot accommodated in the ingot accommodation recess.

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