Expansion device

Abstract

To provide an extension device that appropriately and easily heats an expandable sheet.SOLUTION: An extension device 2 for expanding a sheet 19 of a workpiece unit 11 including a workpiece 13, an expandable sheet 19 fixed to the workpiece 13, and an annular frame 21 to which an outer periphery of the sheet 19 is fixed, includes: an extension unit 28 that holds the frame 21 and expands the sheet 19; a heating unit 30 that has a heat generating portion 84 and a first thermometer 86 for measuring a temperature of the heat generating portion 84, and heats and shrinks an area of the sheet 19 expanded by the extension unit 28 not fixed to the workpiece 13 or the frame 21 with the heat generating portion 84; a second thermometer 90 that measures the temperature of the heat generating portion 84; a moving mechanism 66 that positions the second thermometer so that it faces the heat generating portion 84; and a controller 42 that corrects a predicted value of the actual temperature of the heat generating portion 84.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an expansion device for expanding a sheet fixed to a workpiece.

Background Art

[0002] In the manufacturing process of device chips, a wafer in which devices are formed in a plurality of regions partitioned by a plurality of streets (division planned lines) intersecting each other is used. By dividing this wafer along the streets, chips (device chips) equipped with devices can be obtained. The device chips are incorporated into various electronic devices such as mobile phones and personal computers.

[0003] For dividing a wafer, a cutting device that cuts a workpiece with an annular cutting blade is used. In recent years, the development of a process for dividing a wafer by laser processing has also been promoted. For example, while condensing a laser beam having a wavelength that is transmissive to the wafer inside the wafer, by scanning the laser beam along the street, a modified layer is formed along the street inside the wafer. The region where the modified layer of the wafer is formed becomes more brittle than other regions. Therefore, when an external force is applied to the wafer in which the modified layer is formed, the modified layer functions as a starting point for division, and the wafer is divided along the street.

[0004] For applying an external force to the wafer, for example, an expandable sheet (expand sheet) is used. After fixing the sheet to the wafer, by pulling and expanding the sheet, an external force is applied to the wafer. The expansion of the sheet can be carried out manually, but it may also be carried out by a dedicated expansion device (expand device). When using an expansion device, the expansion operation of the sheet is automated, and the processing efficiency of the wafer is improved.

[0005] Furthermore, when the sheet expansion is released after the wafer has been divided into multiple device chips, slack occurs in the sheet. This slack can cause problems such as misalignment of device chips and damage to device chips due to collisions with each other. Therefore, after releasing the sheet expansion, a process called heat shrinking is sometimes performed, in which the areas where slack has occurred in the sheet are heated to cause thermal shrinkage (see Patent Document 1). Applying heat shrinking eliminates the slack in the sheet and prevents misalignment and damage to device chips. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-177951 [Overview of the project] [Problems that the invention aims to solve]

[0007] As described above, when dividing a workpiece such as a wafer using an expandable sheet, the area where the sheet has slackened after the sheet has been released is heated by a heater. At that time, by measuring and monitoring the heater temperature with a thermometer, the heater temperature can be adjusted so that the sheet is heated to the desired temperature.

[0008] Furthermore, if a thermometer that constantly monitors the heater temperature is in contact with or located near the heating element of the heater, the thermometer will deteriorate more quickly, leading to a decrease in measurement accuracy and increased likelihood of malfunction. Therefore, the thermometer is positioned away from the heating element to indirectly measure its temperature. However, if the heating element and the thermometer are far apart, an error will occur between the temperature measured by the thermometer and the actual temperature of the heating element, making it difficult to set the heater temperature to the desired target value with high accuracy.

[0009] Therefore, when the expansion unit is shipped, a function may be incorporated into the unit that allows the operator to directly measure the actual temperature of the heating element and correct the temperature measured by the thermometer based on the actual temperature of the heating element. This allows for heater temperature control that takes into account the error between the temperature measured by the thermometer and the actual temperature of the heating element.

[0010] However, with prolonged use of the expansion device, the thermometer gradually deteriorates, causing the temperature measured by the thermometer to fluctuate. In this case, the error between the temperature measured by the thermometer and the actual temperature of the heating element also fluctuates, and the correction function set at the time of shipment of the expansion device cannot compensate for this error, making it difficult to properly control the heater temperature.

[0011] Furthermore, it is conceivable to periodically update the correction function incorporated into the expansion device after it has started operation. However, in this case, the operator would have to perform the cumbersome task of directly measuring the temperature of the heating element each time the correction function is updated. In addition, measuring the temperature of the heating element is dangerous because it becomes hot, so it must be done carefully by a skilled operator. Therefore, correcting the heater temperature control is time-consuming and costly.

[0012] The present invention has been made in view of the above problems, and aims to provide an expansion device that can appropriately and easily heat an expandable sheet. [Means for solving the problem]

[0013] According to one aspect of the present invention, an expansion device is provided for expanding a sheet of a workpiece unit, which includes a workpiece, an expandable sheet fixed to the workpiece, and an annular frame to which the outer periphery of the sheet is fixed, the device comprising: an expansion unit that holds the frame and expands the sheet; a heating unit having a heating element and a first thermometer for measuring the temperature of the heating element, which heats and shrinks a portion of the sheet expanded by the expansion unit that is not fixed to the workpiece or the frame; a second thermometer for measuring the temperature of the heating element; a moving mechanism for positioning the second thermometer facing the heating element; and a controller that calculates a predicted value of the actual temperature of the heating element based on the temperature of the heating element measured by the first thermometer, and corrects the predicted value to approach the temperature of the heating element measured by the second thermometer positioned facing the heating element.

[0014] Preferably, the expansion device further comprises a transport unit for transporting the workpiece unit, and the transport unit has the second thermometer and the moving mechanism. Preferably, the second thermometer is a non-contact thermometer. [Effects of the Invention]

[0015] In an expansion device according to one aspect of the present invention, the predicted temperature of the heating element, calculated based on the temperature of the heating element measured by a first thermometer, is corrected to approximate the temperature of the heating element measured by a second thermometer positioned facing the heating element. This reduces the error between the predicted temperature of the heating element and the actual temperature of the heating element, making it possible to control the temperature of the heating element with high precision.

[0016] Furthermore, in an expansion device according to one aspect of the present invention, when measuring the temperature of the heating element with a second thermometer, the second thermometer can be positioned facing the heating element by a moving mechanism. This eliminates the need for the operator to manually measure the temperature of the heating element, thereby reducing the effort and cost required for correcting the temperature control of the heating element. [Brief explanation of the drawing]

[0017] [Figure 1] It is a perspective view showing an expansion device. [Figure 2] It is a perspective view showing a workpiece unit. [Figure 3] FIG. 3(A) is a partial cross-sectional side view showing an expansion unit that holds a workpiece unit, FIG. 3(B) is a partial cross-sectional side view showing an expansion unit that expands a sheet, and FIG. 3(C) is a partial cross-sectional side view showing an expansion unit that releases the expansion of the sheet. [Figure 4] It is a partial cross-sectional side view showing a heating unit that heats a sheet. [Figure 5] It is a partial cross-sectional side view showing an expansion device that controls the temperature of a heat generating part.

Mode for Carrying Out the Invention

[0018] Hereinafter, embodiments according to an aspect of the present invention will be described with reference to the accompanying drawings. First, a configuration example of the expansion device according to the present embodiment will be described. FIG. 1 is a perspective view showing an expansion device 2. In FIG. 1, the X-axis direction (first horizontal direction, left-right direction) and the Y-axis direction (second horizontal direction, front-back direction) are perpendicular to each other. Also, the Z-axis direction (height direction, vertical direction, up-down direction) is perpendicular to the X-axis direction and the Y-axis direction.

[0019] The expansion device 2 includes a base 4 that supports or houses each component that constitutes the expansion device 2. A cassette mounting table 6 is provided at a corner on the front end side of the base 4, and a cassette 8 that can accommodate a plurality of workpiece units 11 is placed on the cassette mounting table 6. Further, a lifting mechanism (not shown) that raises and lowers the cassette mounting table 6 along the Z-axis direction is connected to the cassette mounting table 6. By this lifting mechanism, the height position (position in the Z-axis direction) of the cassette 8 is adjusted so that the workpiece unit 11 can be appropriately carried out from the cassette 8 and the workpiece unit 11 can be carried into the cassette 8.

[0020] FIG. 2 is a perspective view showing a workpiece unit (frame unit) 11. The workpiece unit 11 includes a workpiece 13 that is an object to be processed by the expansion device 2. For example, the workpiece 13 is a disk-shaped wafer made of a semiconductor material such as single-crystalline silicon, and has surfaces (first surface) 13a and a back surface (second surface) 13b that are generally parallel to each other.

[0021] The workpiece 13 is partitioned into a plurality of rectangular regions by a plurality of streets (division planned lines) 15 arranged in a lattice pattern so as to intersect each other. In addition, on the surface 13a side of the plurality of regions partitioned by the streets 15, devices 17 such as IC (Integrated Circuit), LSI (Large Scale Integration), and MEMS (Micro Electro Mechanical Systems) devices are formed respectively. By dividing the workpiece ......

[0022] Note that there are no restrictions on the material, shape, structure, size, etc. of the workpiece 13. For example, the workpiece 13 may be a wafer (substrate) made of a semiconductor other than silicon (GaAs, SiC, InP, GaN, etc.), sapphire, glass, ceramics, resin, metal, etc. Also, there are no restrictions on the type, number, shape, structure, size, arrangement, etc. of the devices 17, and the devices 17 may not be formed on the workpiece 13.

[0023] An expandable sheet (expand sheet) 19 is fixed to the workpiece 13 by applying an external force. For example, as the sheet 19, a tape including a film-shaped base material formed in a circular shape and an adhesive (paste) provided on the base material is used. As the base material, a resin such as polyolefin or polyvinyl chloride having high extensibility can be used. Also, as the adhesive, an epoxy-based, acrylic-based, or rubber-based adhesive, etc. can be used. Note that the adhesive may be an ultraviolet curable resin that cures by irradiation with ultraviolet rays.

[0024] Furthermore, the workpiece 13 is supported by an annular frame 21. The frame 21 is made of a metal such as SUS (stainless steel), and a circular opening 21a is provided in the center of the frame 21, penetrating the frame 21 in the thickness direction. The diameter of the opening 21a is larger than the diameter of the workpiece 13.

[0025] With the workpiece 13 placed inside the opening 21a of the frame 21, the central part of the sheet 19 is fixed to the back surface 13b of the workpiece 13, and the outer periphery of the sheet 19 is fixed to the frame 21. In this way, the workpiece 13 is supported by the frame 21 via the sheet 19. This constitutes a workpiece unit 11 including the workpiece 13, the sheet 19, and the frame 21.

[0026] The sheet 19 may also be a sheet that can be heat-pressed onto the workpiece 13 (a heat-press sheet). The heat-press sheet is made of a thermoplastic resin with a lower melting point than the workpiece 13 and does not contain an adhesive (glue). For example, olefin sheets, styrene sheets, polyester sheets, etc., can be used as heat-press sheets. Examples of olefin sheets include polyethylene sheets and polypropylene sheets. Examples of styrene sheets include polystyrene sheets. Examples of polyester sheets include polyethylene terephthalate sheets and polyethylene naphthalate sheets.

[0027] The heat-seal sheet is placed on the back surface 13b of the workpiece 13. Then, a roller equipped with a heat source (heat roller), for example, is heated to a predetermined temperature and pressed against the heat-seal sheet. As a result, the heat-seal sheet is heated and pressed against the back surface 13b of the workpiece 13 and the frame 21. Consequently, the heat-seal sheet softens and adheres closely to the back surface 13b of the workpiece 13 and the frame 21. In this way, the heat-seal sheet is heat-pressed and fixed to the workpiece 13 and the frame 21.

[0028] The heat-sealable sheet is heated so that its temperature is above its softening point and below its melting point. However, the heat-sealable sheet may not have a clear softening point. In this case, the heat-sealable sheet is heated so that its temperature is above a predetermined temperature (e.g., 20°C) below its melting point and below its melting point.

[0029] For example, if the heat-sealable sheet is a polyethylene sheet, the heating temperature can be set to 120°C to 140°C, and if the heat-sealable sheet is a polypropylene sheet, the heating temperature can be set to 160°C to 180°C. Furthermore, if the heat-sealable sheet is a polystyrene sheet, the heating temperature can be set to 220°C to 240°C. In addition, if the heat-sealable sheet is a polyethylene terephthalate sheet, the heating temperature can be set to 250°C to 270°C, and if the heat-sealable sheet is a polyethylene naphthalate sheet, the heating temperature can be set to 160°C to 180°C.

[0030] On the workpiece 13, a splitting point (trigger for splitting) is formed along the street 15. For example, under conditions in which the workpiece 13 is modified (altered) by multiphoton absorption, a laser beam is irradiated onto the workpiece 13. Specifically, a laser beam that is penetrating to the workpiece 13 is focused inside the workpiece 13 and scanned along the street 15. As a result, a modified layer (altered layer) is formed inside the workpiece 13 along the street 15.

[0031] The region of the workpiece 13 where the modified layer is formed becomes more brittle than other regions. When the sheet 19 is fixed to the workpiece 13 where the modified layer is formed, and the sheet 19 is stretched radially, an external force is applied to the workpiece 13. As a result, the workpiece 13 fractures with the modified layer as the starting point for splitting, and the workpiece 13 is split along the street 15.

[0032] However, the starting point for splitting formed on the workpiece 13 is not limited to the modified layer. For example, by cutting the workpiece 13 with an annular cutting blade, a cutting groove may be formed along the street 15 on the surface 13a side or the back surface 13b side of the workpiece 13. In this case, the cutting groove functions as the starting point for splitting the workpiece 13.

[0033] The workpiece unit 11 is housed in a cassette 8, as shown in Figure 1. When the sheet 19 is expanded by the expansion device 2, the cassette 8 containing multiple workpiece units 11 is set on the cassette mounting base 6.

[0034] A transport unit (transport mechanism) 10 for transporting the workpiece unit 11 is provided near the cassette mounting base 6. The workpiece unit 11 housed in the cassette 8 is transported out of the cassette 8 by the transport unit 10. For example, the transport unit 10 is equipped with a clamp that grips the end of the workpiece unit 11 (frame 21 in Figure 2). The transport unit 10 then moves along the Y-axis away from the cassette 8 while gripping the workpiece unit 11 housed in the cassette 8, and transports the workpiece unit 11 out of the cassette 8.

[0035] Behind the cassette mounting table 6, there is a temporary storage area 12 where the workpiece unit 11 is temporarily placed. The temporary storage area 12 is equipped with an alignment mechanism 14 for aligning the workpiece unit 11 that is temporarily placed in the temporary storage area 12.

[0036] The alignment mechanism 14 includes a pair of guide rails 14a and 14b. The guide rails 14a and 14b are arranged generally parallel to each other along the Y-axis and move toward and away from each other along the X-axis. Each of the guide rails 14a and 14b also includes a support surface that supports the workpiece unit 11 from below and a clamping surface that is generally perpendicular to the support surface.

[0037] The workpiece unit 11, pulled out from the cassette 8 by the transport unit 10, is transported to the temporary placement area 12 and supported by the support surfaces of the guide rails 14a and 14b. Then, the guide rails 14a and 14b move closer to each other along the X-axis, and the workpiece unit 11 is clamped between the gripping surfaces of the guide rails 14a and 14b. This aligns the workpiece unit 11.

[0038] Near the temporary storage area 12, a transport unit (transport mechanism) 16 for transporting the workpiece unit 11 is provided. The transport unit 16 comprises a moving mechanism 18 and a holding part 20 attached to the tip of the moving mechanism 18 to hold the workpiece unit 11. For example, the moving mechanism 18 comprises a transport arm, a rotational drive source (not shown) for rotating the transport arm along the horizontal direction (XY plane direction), and a lifting mechanism (not shown) for raising and lowering the transport arm along the Z axis direction. The holding part 20 comprises a plurality of suction pads 20a (see Figure 5) for suction holding the upper surface of the frame 21 (see Figure 2) of the workpiece unit 11.

[0039] To the side of the temporary placement area 12, a temporary placement area 22 is provided where the workpiece unit 11 is temporarily placed. The temporary placement area 22 is equipped with an alignment mechanism 24 for aligning the workpiece unit 11 that is temporarily placed in the temporary placement area 22. The alignment mechanism 24 comprises a pair of guide rails 24a and 24b. The configuration and function of the guide rails 24a and 24b are the same as those of the guide rails 14a and 14b.

[0040] A transport unit (transport mechanism) 26 for transporting the workpiece unit 11 is provided near the temporary storage area 22. For example, the transport unit 26 is equipped with a clamp that grips the end of the workpiece unit 11 (frame 21 in Figure 2). The transport unit 26 then moves along the Y-axis while gripping the workpiece unit 11, which is supported by the guide rails 24a and 24b, and transports the workpiece unit 11.

[0041] In front of the temporary placement area 22, an expansion unit 28 is positioned to expand the sheet 19 (see Figure 2) fixed to the workpiece 13. The expansion unit 28 expands the sheet 19 by pushing up the workpiece 13 while holding the frame 21. Details of the expansion of the sheet 19 by the expansion unit 28 will be described later (see Figures 3(A) to 3(C)).

[0042] Above the expansion unit 28 is a heating unit 30, which heats and shrinks the sheet 19 expanded by the expansion unit 28. The heating unit 30 eliminates the sagging of the sheet 19 by heating the sheet 19 (see Figure 2) expanded by the expansion unit 28. Details of the heating of the sheet 19 by the heating unit 30 will be described later (see Figure 4).

[0043] A chamber 32 is provided behind the temporary storage area 22. The expansion device 2 also has an expansion unit and a heating unit inside the chamber 32. Therefore, the expansion device 2 can perform expansion and heating of the sheet 19 at two locations: the expansion unit 28 and heating unit 30 in front of the temporary storage area 22, and the expansion unit and heating unit inside the chamber 32.

[0044] Specifically, the transport unit 16 uses the holding unit 20 to suction and hold the workpiece unit 11 placed in the temporary storage area 12, rotates it, and transports it to the temporary storage area 22 or the expansion unit 28. After the workpiece unit 11 is transported to the temporary storage area 22, it is aligned using the guide rails 24a and 24b, and then transported into the chamber 32 by the transport unit 26. After the sheet 19 is expanded and heated in the chamber 32, the workpiece unit 11 is placed in the temporary storage area 22 by the transport unit 26, and then transported from the temporary storage area 22 back to the temporary storage area 12 by the transport unit 16.

[0045] Meanwhile, the workpiece unit 11, which has been transported from the temporary storage area 12 to the expansion unit 28, is held by the expansion unit 28. After the sheet 19 is expanded by the expansion unit 28 and heated by the heating unit 30, the workpiece unit 11 is transported back to the temporary storage area 12 by the transport unit 16.

[0046] Below the alignment mechanism 14 located in the temporary placement area 12, a cleaning unit 34 for cleaning the workpiece 13 is provided. Once the sheet 19 has been expanded and heated, the workpiece unit 11 is transported to the cleaning unit 34 by the transport unit 16.

[0047] The cleaning unit 34 includes a spinner table 36 that holds and rotates the workpiece unit 11. The upper surface of the spinner table 36 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes the holding surface for holding the workpiece unit 11. The holding surface of the spinner table 36 is connected to a suction source (not shown), such as an ejector, via a flow path (not shown), a valve (not shown), etc., formed inside the spinner table 36.

[0048] A rotational drive source (not shown), such as a motor, is connected to the spinner table 36 to rotate the spinner table 36 around a rotation axis that is approximately parallel to the Z-axis direction. In addition, multiple clamps 38 are provided around the spinner table 36 to grip the end of the workpiece unit 11 (frame 21 in Figure 2). When the workpiece unit 11 is being cleaned, the workpiece 13 is held by suction to the spinner table 36 via the sheet 19, and the frame 21 is gripped by the multiple clamps 38.

[0049] The cleaning unit 34 also includes a nozzle (not shown) for supplying cleaning fluid. The nozzle is located above the holding surface of the spinner table 36 and supplies cleaning fluid toward the workpiece 13 held by the spinner table 36. As the cleaning fluid, a liquid such as pure water or a mixed fluid of a liquid (such as pure water) and a gas (such as air) can be used.

[0050] The workpiece unit 11 is held by the spinner table 36, and the workpiece 13 is cleaned by supplying cleaning fluid from a nozzle to the workpiece 13 while rotating the spinner table 36. Once the cleaning of the workpiece 13 is complete, the workpiece unit 11 is placed on the guide rails 14a and 14b by the transport unit 16.

[0051] A chamber 40 is provided behind the temporary placement area 12. A UV irradiation unit is located in the chamber 40 to irradiate the workpiece unit 11 with ultraviolet light. The UV irradiation unit comprises a support table (not shown) that supports the workpiece unit 11 and a UV lamp (not shown) that irradiates the sheet 19 of the workpiece unit 11, which is supported by the support table, with ultraviolet light.

[0052] If the sheet 19 of the workpiece unit 11 contains an adhesive made of ultraviolet-curing resin, the workpiece unit 11, which has been transported on the guide rails 14a and 14b, is transported to the UV irradiation unit by the transport unit 10. Then, ultraviolet light is irradiated onto the sheet 19 from the UV lamp, and the adhesive on the sheet 19 hardens. As a result, the adhesive strength of the sheet 19 decreases, making it possible to easily peel the workpiece 13, after it has been divided, from the sheet 19 in a later process.

[0053] Once the UV irradiation by the UV irradiation unit is complete, the workpiece unit 11 is placed on the guide rails 14a and 14b by the transport unit 10. Subsequently, the workpiece unit 11 is stored in the cassette 8 by the transport unit 10.

[0054] Furthermore, the expansion device 2 includes a controller (control unit, control unit, control device) 42 that controls the expansion device 2. The controller 42 is connected to each component of the expansion device 2 (transport unit 10, alignment mechanism 14, transport unit 16, alignment mechanism 24, transport unit 26, expansion unit 28, heating unit 30, washing unit 34, etc.). The controller 42 controls the operation of the expansion device 2 by outputting control signals to each component of the expansion device 2.

[0055] For example, the controller 42 is comprised of a computer. Specifically, the controller 42 includes a processing unit that performs calculations and other operations to operate the expansion device 2, and a storage unit that stores various information (data, programs, etc.) used to operate the expansion device 2. The processing unit includes a processor such as a CPU (Central Processing Unit). The storage unit includes memory such as ROM (Read Only Memory) and RAM (Random Access Memory).

[0056] Next, the details of the expansion unit 28 will be described. Figure 3(A) is a partial cross-sectional side view showing the expansion unit 28 that holds the workpiece unit 11.

[0057] The extension unit 28 includes a holding table (chuck table) 50 for holding the workpiece 13 of the workpiece unit 11. The upper surface of the holding table 50 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes a holding surface 50a for holding the workpiece 13. The holding surface 50a is made of a porous material such as porous ceramics and is connected to a suction source (not shown) such as an ejector via a flow path 50b, a valve (not shown), etc., provided inside the holding table 50.

[0058] Multiple rollers 52 are provided on the outer periphery of the holding table 50. For example, three or more rollers 52 are arranged at roughly equal intervals along the circumferential direction of the holding surface 50a. The upper ends of each of the multiple rollers 52 are positioned at roughly the same height as the holding surface 50a.

[0059] The holding table 50 is connected to a moving mechanism (lifting mechanism) 54 that moves (lifts and lowers) the holding table 50 along the Z-axis. For example, the moving mechanism 54 is made up of an air cylinder and comprises a cylinder case 56 and a cylindrical piston rod 58 whose lower end is inserted into the cylinder case 56. The holding table 50 is fixed to the upper end of the piston rod 58. When the moving mechanism 54 is activated, the amount the piston rod 58 protrudes from the cylinder case 56 changes, and the holding table 50 moves up and down along the Z-axis. This adjusts the height position of the holding table 50.

[0060] A frame holding unit 60 is provided around the holding table 50 to hold the frame 21 of the workpiece unit 11. The frame holding unit 60 includes a frame support portion 62 that supports the frame 21 from below and a frame pressing portion 72 that presses down on the frame 21 from above.

[0061] The frame support section 62 includes an annular frame support base 64. The frame support base 64 is a cylindrical member made of metal, glass, ceramics, resin, etc. The upper surface of the frame support base 64 is a flat surface that is generally parallel to the horizontal plane (XY plane) and constitutes the support surface 64a that supports the frame 21. In addition, a circular opening 64b is provided in the center of the frame support base 64, which penetrates the frame support base 64 in the thickness direction (height direction). The diameter of the opening 64b of the frame support base 64 is larger than the diameter of the holding surface 50a of the holding table 50.

[0062] Multiple moving mechanisms (lifting mechanisms) 66 are connected to the frame support base 64, which move (lift) the frame support base 64 along the Z-axis direction. For example, four sets of moving mechanisms 66 are arranged at roughly equal intervals along the circumferential direction of the frame support base 64.

[0063] For example, the moving mechanism 66 is composed of an air cylinder and comprises a cylinder case 68 and a cylindrical piston rod 70 whose lower end is inserted into the cylinder case 68. The upper ends of multiple piston rods 70 are each fixed to the lower surface of the frame support base 64. When multiple moving mechanisms 66 are operated simultaneously, the amount of protrusion of the piston rods 70 from the cylinder case 68 changes, causing the frame support base 64 to move up and down along the Z-axis. This adjusts the height position of the frame support base 64.

[0064] The frame retaining portion 72 is a disc-shaped member made of metal, glass, ceramics, resin, etc., and is formed in an annular shape with approximately the same diameter as the frame support base 64. The lower surface of the frame retaining portion 72 is a flat surface that is approximately parallel to the horizontal plane (XY plane) and constitutes the retaining surface 72a that holds the frame 21. In addition, a circular opening 72b is provided in the center of the frame retaining portion 72, which penetrates the frame retaining portion 72 in the thickness direction. The diameter of the opening 72b of the frame retaining portion 72 is larger than the diameter of the retaining surface 50a of the retaining table 50. For example, the opening 72b of the frame retaining portion 72 is formed with approximately the same diameter as the opening 64b of the frame support base 64.

[0065] The holding table 50 is positioned so that its holding surface 50a overlaps with the opening 64b of the frame support base 64. Furthermore, a moving mechanism (not shown) is connected to the frame retaining portion 72, which moves the frame retaining portion 72 along the horizontal direction (XY plane direction). By moving the frame retaining portion 72 with the moving mechanism, the frame retaining portion 72 can be positioned to overlap with the frame support base 64.

[0066] When the sheet 19 is expanded by the expansion unit 28 to divide the workpiece 13, first, the holding surface 50a of the holding table 50 and the support surface 64a of the frame support base 64 are positioned at approximately the same height. Then, the workpiece unit 11 is transported to the expansion unit 28 by the transport unit 16 (see Figure 1) and held by the holding table 50 and the frame holding unit 60. Specifically, with the frame holding portion 72 retracted to a position where it does not overlap with the frame support base 64, the workpiece 13 is placed on the holding surface 50a of the holding table 50 and the frame 21 is placed on the support surface 64a of the frame support base 64.

[0067] Next, the frame retaining portion 72 is positioned directly above the frame support base 64, and the holding table 50 and the frame support base 64 are raised by the moving mechanisms 54 and 66. As a result, with the workpiece 13 supported by the holding surface 50a of the holding table 50, the frame 21 is clamped and fixed between the support surface 64a of the frame support base 64 and the retaining surface 72a of the frame retaining portion 72.

[0068] Figure 3(B) is a partial cross-sectional side view showing an expansion unit 28 that expands the sheet 19. When the workpiece unit 11 is held by the holding table 50 and the frame holding unit 60, the moving mechanism 54 is activated and the holding table 50 rises, and the holding surface 50a of the holding table 50 fits into the opening 72b of the frame retaining portion 72. As a result, the sheet 19 is pulled radially while being supported by the multiple rollers 52 and expands radially outward.

[0069] When the sheet 19 is expanded, an external force is applied to the workpiece 13 fixed to the sheet 19. As a result, the workpiece 13 breaks starting from the splitting points formed along the street 15, and is divided into multiple chips (device chips) 23, each having a device 17 (see Figure 2).

[0070] Figure 3(C) is a partial cross-sectional side view showing the expansion unit 28 that releases the expansion of the sheet 19. When the sheet 19 expands and the workpiece 13 is divided, the moving mechanism 54 is activated and the holding table 50 is lowered. This releases the expansion of the sheet 19. When lowering the holding table 50, the suction force (negative pressure) of the suction source is applied to the holding surface 50a of the holding table 50 to hold the sheet 19 by suction, thereby preventing displacement of the multiple chips 23.

[0071] As shown in Figure 3(C), when the expansion of the sheet 19 is released, slack occurs, particularly in the areas of the sheet 19 that are not fixed to the workpiece 13 or the frame 21 (unfixed areas). This slack in the sheet 19 can cause misalignment of the chips 23 or damage to the chips 23 due to collisions with each other. Therefore, after releasing the expansion of the sheet 19, the slack in the areas of the sheet 19 is heated to cause thermal contraction, thereby eliminating the slack in the sheet 19.

[0072] Figure 4 is a partial cross-sectional side view showing a heating unit 30 for heating the sheet 19. The heating unit 30 is composed of a heater capable of heating the sheet 19. For example, the heating unit 30 comprises a heat-resistant disc-shaped base 80, a cylindrical rod 82 connected to the upper side of the base 80, and an annular heating element 84 fixed to the lower side of the base 80.

[0073] A moving mechanism (not shown) is connected to the rod 82 for moving the heating unit 30 along the horizontal direction (XY plane direction) and the Z axis direction. The base 80 and the heating element 84 are formed to be approximately the same diameter as the opening 64b of the frame support base 64 and the opening 72b of the frame retaining part 72, and are positioned to overlap with the non-fixed area of ​​the sheet 19.

[0074] When power is supplied to the heating element 84, the heating element 84 generates heat, and the object facing the heating element 84 is heated. For example, the heating element 84 is an annular heating element made of ceramics that emits infrared rays downwards. In this case, the heating unit 30 functions as an infrared heater.

[0075] When the expansion of the sheet 19 by the expansion unit 28 is released, the heating unit 30 is positioned directly above the workpiece unit 11. Subsequently, the heating unit 30 descends and approaches the workpiece unit 11, and the heating element 84 is positioned to face the area of ​​the sheet 19 that is not fixed to the workpiece 13 or the frame 21 (the unfixed area). When the heating element 84 is heated to a predetermined temperature (e.g., 600°C) in this state, the unfixed area of ​​the sheet 19 is heated and thermally contracted, eliminating the sagging that has occurred in the unfixed area.

[0076] Furthermore, the heating unit 30 is equipped with a thermometer (first thermometer) 86 for measuring the temperature of the heat-generating section 84. The thermometer 86 continuously measures the temperature of the heat-generating section 84 while the heating unit 30 is operating and the heat-generating section 84 is generating heat, and outputs the result to the controller 42. This allows the temperature of the heat-generating section 84 to be monitored while the heating unit 30 is operating.

[0077] Furthermore, if the thermometer 86, which constantly monitors the temperature of the heat-generating section 84, is in contact with the heat-generating section 84 or is located near the heat-generating section 84 and facing it, the thermometer 86 will deteriorate more quickly, leading to a decrease in measurement accuracy and increased likelihood of malfunction. Therefore, the thermometer 86 is installed so as not to be in contact with the heat-generating section 84 and not to be facing it. For example, the thermometer 86 is installed inside the base 80 at a distance from the heat-generating section 84, and indirectly measures the temperature of the heat-generating section 84 by detecting the heat conducted from the heat-generating section 84 through other heat-conducting materials (such as the base 80).

[0078] A thermocouple or the like can be used as the thermometer 86. However, there are no restrictions on the type of thermometer 86 as long as it can measure and monitor the temperature of the heat-generating part 84 over a long period of time. There are also no restrictions on the number of thermometers 86. For example, multiple thermometers 86 can be arranged at roughly equal intervals along the circumferential direction of the base 80.

[0079] The controller 42 adjusts the temperature of the heating element 84 based on the temperature of the heating element 84 input from the thermometer 86. For example, if the temperature measured by the thermometer 86 has not reached the target temperature of the heating element 84, the controller 42 increases the power supplied to the heating element 84 to bring the temperature of the heating element 84 closer to the target value. This allows the temperature of the heating element 84 to be maintained at a temperature suitable for the thermal shrinkage of the sheet 19.

[0080] However, as mentioned above, since the thermometer 86 indirectly measures the temperature of the heat-generating element 84, there will be an error between the temperature measured by the thermometer 86 and the actual temperature of the heat-generating element 84. Therefore, even if the temperature of the heat-generating element 84 is adjusted based on the temperature measured by the thermometer 86, it may be difficult to control the temperature of the heat-generating element 84 with high precision.

[0081] Therefore, in this embodiment, the temperature of the heating element 84 is directly measured with another thermometer, and the temperature measured by the thermometer 86 is corrected based on the directly measured temperature of the heating element 84. This improves the accuracy of temperature control of the heating element 84.

[0082] Figure 5 is a partial cross-sectional side view showing the extension device 2 that controls the temperature of the heat-generating section 84. The temperature of the heat-generating section 84 is controlled by the controller 42. Figure 5 also illustrates a block diagram showing the functional configuration of the controller 42.

[0083] The expansion device 2 includes a thermometer (second thermometer) 90 for measuring the temperature of the heating element 84. For example, the thermometer 90 is mounted on the transport unit 16 described above. Specifically, the transport unit 16 includes a moving mechanism 18 and a holding unit 20, as well as a thermometer 90 mounted on the upper side of the holding unit 20. The lower side of the holding unit 20 is provided with a plurality of suction pads 20a for suction holding the frame 21 (see Figure 2) of the workpiece unit 11.

[0084] The thermometer 90 measures the temperature of the heating element 84 at predetermined timings. Specifically, first, the moving mechanism 18 moves the holding part 20 and the thermometer 90 along the horizontal direction (XY plane direction) to position the thermometer 90 facing the heating element 84. Specifically, as shown in Figure 5, the thermometer 90 is positioned directly below the heating element 84 (overlapping in the Z-axis direction). Then, when the heating element 84 is heated to a predetermined temperature and infrared rays are irradiated toward the thermometer 90, the temperature of the heating element 84 is measured by the thermometer 90.

[0085] The thermometer 90 may be a contact-type thermometer that measures the temperature of the heating element 84 by contacting it, or a non-contact-type thermometer that measures the temperature of the heating element 84 without contacting it. In particular, a non-contact-type thermometer 90 is preferable because it does not need to be in contact with the high-temperature heating element 84, thus reducing the likelihood of deterioration of the thermometer 90.

[0086] An infrared radiation thermometer or the like can be used as the thermometer 90. However, there are no restrictions on the type of thermometer 90 as long as it can measure the temperature of the heat-generating part 84 with higher accuracy than the thermometer 86. There are also no restrictions on the number of thermometers 90. For example, multiple thermometers 90 can be fixed to the upper surface of the holding part 20.

[0087] The thermometer 90 directly measures the temperature of the heating element 84 when it is in contact with the heating element 84, or when it is facing the heating element 84 and there are no other components between the heating element 84 and the thermometer 90. Therefore, the thermometer 90 can measure the actual temperature of the heating element 84 more accurately than the thermometer 86 built into the heating unit 30. In other words, the difference between the actual temperature of the heating element 84 and the temperature measured by the thermometer 90 is smaller than the difference between the actual temperature of the heating element 84 and the temperature measured by the thermometer 86. The temperature measured by the thermometer 90 is then input to the controller 42.

[0088] The controller 42 includes a processing unit 100 and a memory unit 110. The processing unit 100 processes information (signals, data, etc.) input from the outside and generates and outputs various types of information (signals, data, etc.) to the outside. The memory unit 110 stores various types of information (data, programs, etc.) used in the processing of the processing unit 100.

[0089] The processing unit 100 includes a temperature calculation unit 102 that calculates the temperature of the heat-generating unit 84 and a power control unit 104 that controls the power supplied to the heat-generating unit 84. The storage unit 110 also includes a temperature information storage unit 112 that stores temperature information showing the correspondence between the temperature of the heat-generating unit 84 measured by the thermometer 86 (measured temperature) and the predicted value of the actual temperature of the heat-generating unit 84 (predicted temperature). For example, a table or graph (function) showing the relationship between the measured temperature and the predicted temperature is stored in the temperature information storage unit 112 as temperature information.

[0090] There are no restrictions on how temperature information is obtained. For example, temperature information can be obtained by conducting a test using the heating unit 30 in advance. Specifically, the heating element 84 is heated to a predetermined temperature, and the temperature measured by the thermometer 86 at that time is recorded. Then, the same process is repeated while changing the temperature of the heating element 84. This provides temperature information showing the relationship between the temperature measured by the thermometer 86 and the predicted temperature based on the measured temperature of the heating element 84.

[0091] The temperature of the heat-generating section 84 measured by the thermometer 86 (measured temperature) is input to the temperature calculation unit 102. The temperature calculation unit 102 then accesses the temperature information storage unit 112 to read the temperature information and calculates a predicted value of the actual temperature of the heat-generating section 84 (predicted temperature) by applying the measured temperature to the correspondence indicated by the temperature information. If measured temperatures are input to the temperature calculation unit 102 from multiple thermometers 86, the temperature calculation unit 102 may calculate the predicted temperature based on the average value of the measured temperatures.

[0092] The predicted temperature calculated by the temperature calculation unit 102 is output to the power control unit 104. The power control unit 104 then controls the power supplied to the heat-generating unit 84 so that its temperature reaches a predetermined target value, assuming that the predicted temperature matches the actual temperature of the heat-generating unit 84. In this way, the power supplied to the heat-generating unit 84 is adjusted based on the temperature measured by the thermometer 86, and the temperature of the heat-generating unit 84 can be maintained within the desired range.

[0093] However, if the heating unit 30 is used for a long period of time, the thermometer 86 will gradually deteriorate, and the temperature measured by the thermometer 86 will fluctuate. In this case, an error will occur between the predicted temperature calculated by the temperature calculation unit 102 and the actual temperature of the heating element 84. As a result, the power control unit 104 may control the power supplied to the heating element 84 based on the incorrect predicted temperature, which could lead to overheating or underheating of the heating element 84.

[0094] Therefore, the controller 42 corrects the predicted temperature to be closer to the temperature of the heating element 84 measured by the thermometer 90 positioned facing the heating element 84. This reduces the error between the predicted temperature of the heating element 84 and the actual temperature of the heating element 84, making it possible to heat the sheet 19 at a more accurate temperature.

[0095] Specifically, first, the temperature of the heat-generating section 84 is measured by thermometer 86 and thermometer 90, respectively. As mentioned above, thermometer 90 is positioned facing the heat-generating section 84, and there are no other components between the heat-generating section 84 and thermometer 90. Therefore, the temperature of the heat-generating section 84 measured by thermometer 90 is closer to the actual temperature of the heat-generating section 84 than the temperature of the heat-generating section 84 measured by thermometer 86.

[0096] Furthermore, the processing unit 100 includes a correction unit 106 that corrects the temperature information stored in the temperature information storage unit 112. The correction unit 106 receives the temperature of the heat-generating unit 84 measured by the thermometer 86 and the temperature of the heat-generating unit 84 measured by the thermometer 90 as input.

[0097] When temperatures are input to the correction unit 106 from thermometers 86 and 90, the correction unit 106 accesses the temperature information storage unit 112 and rewrites the measured temperature included in the temperature information with the temperature measured by thermometer 86, and rewrites the predicted temperature included in the temperature information with the temperature measured by thermometer 90. As a result, the predicted temperature calculated by the temperature calculation unit 102 is corrected to the actual measured temperature of the heat-generating unit 84 measured by thermometer 90. Consequently, the predicted temperature approaches the actual temperature of the heat-generating unit 84.

[0098] Furthermore, if multiple thermometers 86 and 90 are provided, the correction unit 106 may correct the temperature information using the average value of the temperatures measured by thermometer 86 and the average value of the temperatures measured by thermometer 90. In addition, the temperature of the heat-generating section 84 may be measured multiple times using thermometers 86 and 90 while changing the temperature of the heat-generating section 84. In this case, the predicted temperature can be corrected by two-point correction.

[0099] The thermometer 90 is positioned near the heat-generating unit 84 and operates only for a short period of time when correcting the temperature information. Therefore, even if the thermometer 90 is exposed to the high heat emitted by the heat-generating unit 84, deterioration of the thermometer 90 is unlikely to occur.

[0100] The above temperature information correction is performed at a predetermined frequency depending on the degree of deterioration of the thermometer 86. There are no restrictions on the timing of the temperature information correction. For example, the temperature information is corrected when the expansion device 2 is started up or when the expansion device 2 is being maintained. Furthermore, even when the expansion device 2 is in operation, the temperature information can be corrected as long as the heating unit 30 is not heating the sheet 19.

[0101] Furthermore, the correction of the temperature information described above is achieved by executing a program stored in the memory unit 110. Specifically, the memory unit 110 stores a program that describes each process performed by the processing unit 100 (temperature calculation unit 102, power control unit 104, and correction unit 106). The controller 42 then reads the program from the memory unit 110 and executes it to automatically perform the correction of the temperature information.

[0102] As described above, in the expansion device according to this embodiment, the predicted value of the temperature of the heat-generating section 84, calculated based on the temperature of the heat-generating section 84 measured by the thermometer 86, is corrected so that it approaches the temperature of the heat-generating section 84 measured by the thermometer 90 positioned facing the heat-generating section 84. This reduces the error between the predicted value of the temperature of the heat-generating section 84 and the actual temperature of the heat-generating section 84, making it possible to control the temperature of the heat-generating section 84 with high precision.

[0103] Furthermore, in the expansion device according to this embodiment, when measuring the temperature of the heat-generating section 84 with the thermometer 90, the moving mechanism 18 can be used to position the thermometer 90 so that it faces the heat-generating section 84. This eliminates the need for the operator to manually measure the temperature of the heat-generating section 84, thereby reducing the effort and cost required to correct the temperature control of the heat-generating section 84.

[0104] In Figure 5, an example is shown in which a transport unit 16 that transports the workpiece unit 11 is equipped with a thermometer 90 and a moving mechanism 18 for moving the thermometer 90. However, the thermometer 90 and the moving mechanism may be provided in components other than the transport unit 16, or they may be provided separately and independently from other components. For example, the expansion device 2 may be equipped with a thermometer 90 and a dedicated moving mechanism for moving the thermometer 90.

[0105] Furthermore, while Figure 5 illustrates an example where thermometers 86 and 90 are controlled by the controller 42 of the expansion device 2, thermometers 86 and 90 may each be connected to their own dedicated controllers. In this case, the functions of the controller 42 shown in Figure 5 may be implemented in the controllers connected to thermometers 86 and 90.

[0106] Furthermore, the structures, methods, etc., according to the above embodiments can be modified as appropriate without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0107] 11. Workpiece Unit (Frame Unit) 13 Workpiece 13a Surface (first side) 13b Back side (2nd side) 15th Street (planned division line) 17 devices 19 sheets (expandable sheets) 21 frames 21a opening 23 Chips (Device Chips) 2. Expansion device 4 bases 6 Cassette mounting trays 8 cassettes 10. Transport Unit (Transport Mechanism) 12 Temporary placement area 14 Alignment mechanism 14a, 14b Guide rails 16. Transport Unit (Transport Mechanism) 18 Moving mechanism 20 Holding part 20a Suction Pad 22 Temporary area 24 Alignment mechanism 24a, 24b Guide rails 26. Transport Unit (Transport Mechanism) 28 Expansion Units 30 Heating Units 32 chambers 34 Washing Unit 36 Spinner Table 38 clamps 40 chambers 42 Controllers (control units, control units, control devices) 50 Holding Table (Chuck Table) 50a holding surface 50b channel 52 Koro 54. Moving mechanism (lifting mechanism) 56 Cylinder Case 58 Piston Rod 60 Frame holding unit 62 Frame support section 64 Frame support base 64a Support surface 64b aperture 66. Moving mechanism (lifting mechanism) 68 Cylinder Case 70 Piston Rod 72 Frame retaining part 72a Pressing surface 72b aperture 80 base 82 rods 84 Heat-generating part 86 Thermometer (First thermometer) 90 Thermometer (Second thermometer) 100 Processing Unit 102 Temperature calculation section 104 Power Control Unit 106 Correction Unit 110 Memory 112 Temperature information storage section

Claims

1. An expansion device for expanding a sheet of a workpiece unit, which includes a workpiece, an expandable sheet fixed to the workpiece, and an annular frame to which the outer periphery of the sheet is fixed, An extension unit that holds the frame and extends the seat, A heating unit having a heating element and a first thermometer for measuring the temperature of the heating element, which heats and shrinks the portion of the sheet that is not fixed to the workpiece or the frame, which has been expanded by the expansion unit, A second thermometer for measuring the temperature of the heat-generating part, A moving mechanism for positioning the second thermometer so as to face the heating element, An expansion device characterized by having a controller that calculates a predicted value of the actual temperature of the heat-generating part based on the temperature of the heat-generating part measured by the first thermometer, and corrects the predicted value to approach the temperature of the heat-generating part measured by the second thermometer positioned facing the heat-generating part.

2. The system further comprises a transport unit for transporting the workpiece unit, The expansion device according to claim 1, characterized in that the transport unit has the second thermometer and the moving mechanism.

3. The expansion device according to claim 1 or 2, characterized in that the second thermometer is a non-contact type thermometer.

Images