Material application device and material application method
The material coating apparatus and method provide accurate filler application to stacked wafers by measuring weight changes, addressing the inaccuracy of existing methods and preventing damage, thus ensuring consistent performance.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- EBARA CORP
- Filing Date
- 2025-12-10
- Publication Date
- 2026-07-02
Smart Images
Figure JP2025043040_02072026_PF_FP_ABST
Abstract
Description
Material Coating Apparatus and Material Coating Method
[0001] The present invention relates to a material coating apparatus and a material coating method for applying a filler to an edge portion of a stacked wafer composed of a plurality of wafers bonded to each other, and particularly relates to a technique for measuring the amount of the filler applied to the edge portion of the stacked wafer.
[0002] In recent years, in order to achieve further high density and high functionality of semiconductor devices, the development of three-dimensional mounting technology for stacking a plurality of wafers for three-dimensional integration has been progressing. In the three-dimensional mounting technology, for example, the device surface of the first wafer on which an integrated circuit and electrical wiring are formed is joined to the device surface of the second wafer on which an integrated circuit and electrical wiring are formed. Further, after the first wafer is joined to the second wafer, the second wafer is thinned by a polishing apparatus or a grinding apparatus. In this way, integrated circuits can be stacked in a direction perpendicular to the device surfaces of the first wafer and the second wafer.
[0003] In the three-dimensional mounting technology, three or more wafers may be joined. For example, after the second wafer joined to the first wafer is thinned, the third wafer is joined to the second wafer and the third wafer is thinned. In this specification, the form of a plurality of wafers joined to each other may be referred to as a "stacked wafer".
[0004] Usually, the edge portion of a wafer is pre-polished into a rounded shape or a chamfered shape in order to prevent cracking or chipping. When the second wafer having such a shape is ground, as a result, a sharp end portion is formed on the second wafer. This sharp end portion (hereinafter referred to as a knife edge portion) is formed by the back surface of the ground second wafer and the outer peripheral surface of the second wafer. Such a knife edge portion is liable to chip due to physical contact, and the stacked wafer itself may be damaged during the conveyance of the stacked wafer. Further, if the joining between the first wafer and the second wafer is not sufficient, the second wafer may crack during grinding.
[0005] Therefore, to prevent cracking and chipping at the knife edge, a filler material is applied to the edge of the stacked wafers before grinding the second wafer. The filler material is applied to the gap between the edge of the first wafer and the edge of the second wafer. The filler material supports the knife edge formed after grinding the second wafer, preventing cracking and chipping of the knife edge.
[0006] Japanese Patent Publication No. 2023-032581
[0007] The process of applying filler material to the edges of the laminated wafer ends when a predetermined application time has elapsed. Therefore, the amount of filler material applied is estimated from the application time. However, the application time may not accurately reflect the actual amount applied, and filling defects such as insufficient or excessive filler material application may occur. If the laminated wafer is processed in subsequent processes with filling defects, it may damage the laminated wafer or adversely affect the performance of the laminated wafer and the process.
[0008] Therefore, the present invention provides a material coating apparatus and a material coating method that can accurately determine the amount of filler applied to the gap between the edge of the first wafer and the edge of the second wafer.
[0009] In one embodiment, a material coating apparatus is provided for coating the edge portion of a stacked wafer, comprising: a wafer holding unit for holding the stacked wafer; a rotation mechanism for rotating the wafer holding unit to rotate the stacked wafer around a predetermined wafer rotation axis; a coating module for coating the edge portion of the stacked wafer on the wafer holding unit rotated by the rotation mechanism; a load measuring device for measuring the weight of the stacked wafer; and a coating amount calculator that acquires a first weight measurement value output from the load measuring device before the filler is coated on the stacked wafer, acquires a second weight measurement value output from the load measuring device when the filler is coated on the stacked wafer or after the filler is coated on the stacked wafer, and calculates the amount of the filler coated on the stacked wafer by subtracting the first weight measurement value from the second weight measurement value.
[0010] In one embodiment, the load measuring device supports the wafer holder. In one embodiment, the wafer holder comprises a plurality of roller chucks, and the load measuring device is a plurality of load measuring devices that each support the plurality of roller chucks. In one embodiment, the wafer holder comprises a plurality of upper roller chucks and a plurality of lower roller chucks that hold the stacked wafers in a vertical position, and the load measuring device is a plurality of load measuring devices attached to the plurality of lower roller chucks. In one embodiment, the wafer holder comprises a plurality of upper roller chucks and a plurality of lower roller chucks that hold the stacked wafers in a vertical position, and the load measuring device is arranged between the plurality of lower roller chucks. In one embodiment, the coating amount calculator is configured to obtain the second weight measurement value output from the load measuring device when the filler is being coated onto the laminated wafer, calculate the amount of the filler applied to the laminated wafer by subtracting the first weight measurement value from the second weight measurement value, and determine the coating endpoint when the amount of the filler reaches a predetermined filling threshold.
[0011] In one embodiment, a material coating method is provided for coating the edge portion of a stacked wafer, wherein the stacked wafer is held by a wafer holder, the wafer holder is rotated by a rotation mechanism to rotate the stacked wafer around a predetermined wafer rotation axis, a coating module is applied to the edge portion of the rotating stacked wafer, a first weight measurement value is obtained from a load measuring device that measures the weight of the stacked wafer before the filler is applied to the stacked wafer, a second weight measurement value is obtained from the load measuring device when the filler is applied to the stacked wafer or after the filler is applied to the stacked wafer, and the amount of the filler applied to the stacked wafer is calculated by subtracting the first weight measurement value from the second weight measurement value.
[0012] In one embodiment, the load measuring device supports the wafer holder. In one embodiment, the wafer holder comprises a plurality of roller chucks, and the load measuring device is a plurality of load measuring devices each supporting the plurality of roller chucks. In one embodiment, the wafer holder comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafer in a vertical position, and the load measuring device is a plurality of load measuring devices each attached to the plurality of lower roller chucks. In one embodiment, the wafer holder comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafer in a vertical position, and the load measuring device is positioned between the plurality of lower roller chucks. In one embodiment, the second weight measurement value is a measurement value output from the load measuring device when the filler is being applied to the stacked wafer, and the material application method further includes determining an application endpoint when the amount of the filler reaches a predetermined filling threshold.
[0013] The difference between the first weight measurement taken before the filler material is applied to the laminated wafer and the second weight measurement taken when the filler material is applied to the laminated wafer, or after the filler material has been applied to the laminated wafer, corresponds to the amount of filler material applied to the periphery of the laminated wafer. Therefore, the application amount calculator can accurately determine the amount of filler material applied to the laminated wafer by subtracting the first weight measurement from the second weight measurement.
[0014] This is a side view showing one embodiment of a material coating apparatus. This is a top view showing one embodiment of a material coating apparatus. This is a flowchart showing one embodiment of coating a laminated wafer with filler. This is a flowchart showing another embodiment of coating a laminated wafer with filler. This is a front view showing another embodiment of a material coating apparatus. This is an enlarged view from the direction indicated by arrow A in Figure 5. This is a front view showing yet another embodiment of a material coating apparatus. This is a diagram showing the measurement of the weight of a laminated wafer using a load measuring device. This is a flowchart showing one embodiment of coating a laminated wafer with filler.
[0015] Embodiments of the present invention will be described below with reference to the drawings. Figure 1 is a side view showing one embodiment of the material coating apparatus 1, and Figure 2 is a plan view showing one embodiment of the material coating apparatus 1. The material coating apparatus 1 is an apparatus for coating a filler material F onto a laminated wafer Ws in which a first wafer W1 and a second wafer W2 are joined. The material coating apparatus 1 includes a wafer holding unit 2 that holds and rotates the laminated wafer Ws horizontally, a coating module 3 that coats the filler material F onto the laminated wafer Ws, a curing apparatus 4 for curing the coated filler material F, and an operation control unit 10 that controls the operation of the wafer holding unit 2, the coating module 3, and the curing apparatus 4.
[0016] The operation control unit 10 is comprised of at least one computer. The operation control unit 10 includes a storage device 10a in which a program is stored, and an arithmetic unit 10b that performs calculations according to the instructions contained in the program. The storage device 10a includes a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of the arithmetic unit 10b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the operation control unit 10 is not limited to these examples.
[0017] The wafer holding unit 2 includes a wafer stage 12 that holds the back surface (bottom surface) of the stacked wafer Ws by vacuum suction, and a rotation shaft 15 connected to the center of the wafer stage 12. The stacked wafer Ws is placed on the wafer stage 12 so that the center of the stacked wafer Ws coincides with the axis of the rotation shaft 15. The material coating apparatus 1 includes a rotation mechanism 18 that rotates the wafer stage 12 and the rotation shaft 15 of the wafer holding unit 2. The rotation mechanism 18 includes a motor (not shown). As shown in Figure 1, the rotation mechanism 18 is configured to rotate the wafer stage 12 and the stacked wafer Ws integrally in the direction indicated by the arrow, about the wafer rotation axis Cr. In this embodiment, the wafer rotation axis Cr extends in the vertical direction.
[0018] The coating module 3 is located radially outward of the stacked wafer Ws on the wafer holding section 2, and is configured to apply a filler material F to the gap G between the edge portion E1 of the first wafer W1 and the edge portion E2 of the second wafer W2 of the stacked wafer Ws. This gap G is formed around the entire circumference of the stacked wafer Ws. The coating module 3 is positioned to face the gap G between the edge portion E1 of the first wafer W1 and the edge portion E2 of the second wafer W2.
[0019] The specific configuration of the coating module 3 is not particularly limited, as long as the coating module 3 can discharge the filler F toward the gap G between the stacked wafers Ws. In one embodiment, the coating module 3 may consist of a combination of a piston and a syringe configured to discharge the filler F by gas pressure, or it may consist of a screw feeder.
[0020] As shown in Figures 1 and 2, the curing apparatus 4 is located radially outward of the stacked wafer Ws on the wafer holding section 2. The curing apparatus 4 is positioned downstream of the coating module 3 in the rotational direction of the stacked wafer Ws and is configured to cure the filler F applied to the stacked wafer Ws by the coating module 3. The curing of the filler F by the curing apparatus 4 is performed while the stacked wafer Ws is rotating. In this embodiment, the filler F is a thermosetting filler F. An example of such a filler F is a thermosetting resin.
[0021] The curing apparatus 4 is an air heater configured to blow hot air onto the filler material F applied to the laminated wafer Ws. The curing apparatus 4 is configured to allow adjustment of the air pressure and temperature of the blown hot air. The filler material F heated by the hot air hardens through a crosslinking reaction. If the filler material F contains a solvent, the solvent is evaporated by heating. The curing apparatus 4 is not limited to an air heater; it may also be a lamp heater or other configuration as long as it can heat and harden the filler material F.
[0022] In this embodiment, the filler F is a thermosetting filler, but in one embodiment, the filler F may be an ultraviolet curing filler. In this case, the curing device 4 may be a UV irradiation device that cures the filler F by irradiating it with ultraviolet light. If the filler F contains a solvent, it may be heated using an air heater or the like to volatilize the solvent. In yet another embodiment, the coating module 3 may be configured to deposit the filler F in the gap G by causing a high-speed jet of the filler F to collide with the edge portion E1 of the first wafer W1 and the edge portion E2 of the second wafer W2. In this case, the curing device 4 may be omitted.
[0023] The material coating apparatus 1 further includes a load measuring device 21 for measuring the weight of a stacked wafer Ws, and a coating amount calculator 22 for calculating the amount of filler F coated on the stacked wafer Ws from the measured weight. The load measuring device 21 is incorporated into the wafer holding unit 2. More specifically, the load measuring device 21 is supported by a rotating shaft 15, and the load measuring device 21 supports the wafer stage 12. The load measuring device 21 is positioned between the wafer stage 12 and the rotating shaft 15. Therefore, the load measuring device 21 can measure the weight of the stacked wafer Ws on the wafer stage 12.
[0024] The coating amount calculator 22 is electrically connected to the operation control unit 10. The coating amount calculator 22 is configured to acquire a first weight measurement value output from the load measuring device 21 before the filler material F is applied to the laminated wafer Ws, acquire a second weight measurement value output from the load measuring device 21 when the filler material F is applied to the laminated wafer Ws, or after the filler material F is applied to the laminated wafer Ws, and calculate the amount of filler material F applied to the laminated wafer Ws by subtracting the first weight measurement value from the second weight measurement value. The difference between the first weight measurement value and the second weight measurement value corresponds to the amount of filler material F applied to the periphery of the laminated wafer Ws. Therefore, the coating amount calculator 22 can accurately determine the amount of filler material F applied to the laminated wafer Ws by subtracting the first weight measurement value from the second weight measurement value.
[0025] The coating amount calculator 22 consists of at least one computer. The coating amount calculator 22 includes a storage device 22a in which a program is stored, and an arithmetic unit 22b that performs calculations according to the instructions contained in the program. The storage device 22a includes a main memory such as random access memory (RAM) and an auxiliary storage device such as a hard disk drive (HDD) or solid state drive (SSD). Examples of the arithmetic unit 22b include a CPU (central processing unit) and a GPU (graphics processing unit). However, the specific configuration of the coating amount calculator 22 is not limited to these examples. In one embodiment, the coating amount calculator 22 and the operation control unit 10 may consist of a single computer.
[0026] Figure 3 is a flowchart illustrating one embodiment of applying a filler F to a stacked wafer Ws. In step 101, the stacked wafer Ws is transported to the wafer holding unit 2 by a transport robot (not shown) and placed on the wafer stage 12. The stacked wafer Ws is held by the wafer stage 12 of the wafer holding unit 2. In step 102, the load measuring device 21 outputs a first weight measurement value while the stacked wafer Ws is held in the wafer holding unit 2. The coating amount calculator 22 obtains the first weight measurement value from the load measuring device 21. In step 103, the operation control unit 10 commands the rotation mechanism 18 to rotate the wafer holding unit 2 and the stacked wafer Ws by the rotation mechanism 18, and commands the coating module 3 to apply the filler F to the edge portion of the stacked wafer Ws.
[0027] In step 104, the operation control unit 10, after a predetermined time has elapsed, issues a command to the coating module 3 to finish coating the edges of the stacked wafer Ws with the filler F. Furthermore, the operation control unit 10 issues a command to the rotation mechanism 18 to stop the rotation of the stacked wafer Ws. In step 105, the load measuring device 21 outputs a second weight measurement value while the stacked wafer Ws is held in the wafer holding unit 2. The coating amount calculator 22 obtains the second weight measurement value from the load measuring device 21. In step 106, the coating amount calculator 22 calculates (determines) the amount of filler F coated on the stacked wafer Ws by subtracting the first weight measurement value from the second weight measurement value.
[0028] Figure 4 is a flowchart showing another embodiment of applying a filler F to a stacked wafer Ws. In step 201, the stacked wafer Ws is transported to the wafer holding unit 2 by a transport robot (not shown) and placed on the wafer stage 12. The stacked wafer Ws is held by the wafer stage 12 of the wafer holding unit 2. In step 202, the load measuring device 21 outputs a first weight measurement value while the stacked wafer Ws is held in the wafer holding unit 2. The coating amount calculator 22 obtains the first weight measurement value from the load measuring device 21.
[0029] In step 203, the operation control unit 10 gives a command to the rotation mechanism 18 to rotate the wafer holding unit 2 and the stacked wafer Ws by the rotation mechanism 18, and at the same time gives a command to the coating module 3 to coat the filler material F onto the edge portion of the stacked wafer Ws.
[0030] In step 204, the load measuring device 21 outputs a second weight measurement when the filler F is applied to the edge of the stacked wafer Ws. The coating amount calculator 22 obtains the second weight measurement from the load measuring device 21.
[0031] In step 205, the coating amount calculator 22 calculates (determines) the amount of filler F coated on the laminated wafer Ws by subtracting the first weight measurement from the second weight measurement. In step 206, the coating amount calculator 22 determines whether the amount of filler F has reached a predetermined filling threshold. If the amount of filler F has not reached the predetermined filling threshold (NO in step 206), the process flow returns to step 204.
[0032] In step 207, if the amount of filler F reaches a predetermined filling threshold (YES in step 206), the coating amount calculator 22 determines the coating endpoint where the amount of filler F has reached the filling threshold. The coating amount calculator 22 transmits a detection signal indicating the coating endpoint to the operation control unit 10. In step 208, upon receiving the detection signal indicating the coating endpoint, the operation control unit 10 issues a command to the coating module 3 to terminate the coating of filler F to the edges of the stacked wafer Ws. Furthermore, the operation control unit 10 issues a command to the rotation mechanism 18 to stop the rotation of the wafer stage 12 of the wafer holding unit 2 and the stacked wafer Ws.
[0033] Figure 5 is a front view showing another embodiment of the material coating apparatus 1. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figures 1 to 4, so redundant descriptions are omitted.
[0034] The material coating apparatus 1 of this embodiment includes a wafer holding section 2 equipped with a plurality of wafer chucks 25A, 25B that hold the edge portion of a stacked wafer Ws in a vertical position, and a plurality of rotation mechanisms 18 that rotate the plurality of wafer chucks 25A, 25B. The wafer chucks 25A, 25B of this embodiment are cylindrical roller chucks. The stacked wafer Ws is held in a vertical position by the plurality of wafer chucks 25A, 25B.
[0035] The wafer chucks 25A and 25B include a plurality of upper wafer chucks 25A that hold the upper part of the edge portion of the stacked wafer Ws, and a plurality of lower wafer chucks 25B that hold the lower part of the edge portion of the stacked wafer Ws. The plurality of upper wafer chucks 25A are located above a predetermined wafer rotation axis Cr, and the plurality of lower wafer chucks 25B are located below the wafer rotation axis Cr. In this embodiment, the wafer rotation axis Cr extends horizontally. Each of the wafer chucks 25A and 25B has an annular groove (not shown). The stacked wafer Ws is held by the wafer chucks 25A and 25B when the edge portion of the stacked wafer Ws engages with the annular groove of the wafer chucks 25A and 25B.
[0036] Each of the multiple lower wafer chucks 25B incorporates multiple load measuring devices 21 that contact the edge portion of the stacked wafer Ws. Each load measuring device 21 constitutes a part of the annular groove of each lower wafer chuck 25B. Each load measuring device 21 rotates integrally with the lower wafer chuck 25B while supporting the edge portion of the stacked wafer Ws. The multiple load measuring devices 21 are electrically connected to the coating amount calculator 22. Each load measuring device 21 measures the weight of the stacked wafer Ws, and the measured weight is transmitted from each load measuring device 21 to the coating amount calculator 22.
[0037] The coating amount calculator 22 is configured to acquire a first weight measurement value output from the load measuring device 21 before the filler material is applied to the laminated wafer Ws, acquire a second weight measurement value output from the load measuring device 21 when the filler material is applied to the laminated wafer Ws, or after the filler material has been applied to the laminated wafer Ws, and calculate the amount of filler material applied to the laminated wafer Ws by subtracting the first weight measurement value from the second weight measurement value.
[0038] In this embodiment, multiple load measuring devices 21 are provided. Therefore, the first weight measurement may be the sum or average value of multiple weight measurements output from the multiple load measuring devices 21 before the filler material is applied to the laminated wafer Ws. The second weight measurement may be the sum or average value of multiple weight measurements output from the multiple load measuring devices 21 when the filler material is applied to the laminated wafer Ws, or after the filler material has been applied to the laminated wafer Ws. The coating amount calculator 22 calculates the first weight measurement and the second weight measurement by calculating the sum or average value of the multiple weight measurements.
[0039] The material coating apparatus 1 of this embodiment is equipped with four wafer chucks 25A, 25B. Therefore, the four wafer chucks 25A, 25B hold the edges of the stacked wafer Ws. The four wafer chucks 25A, 25B are arranged around a predetermined wafer rotation axis Cr. This wafer rotation axis Cr is an imaginary rotation centerline. In one embodiment, only three wafer chucks 25A, 25B may be provided, or five or more wafer chucks 25A, 25B may be provided.
[0040] Multiple wafer chucks 25A, 25B are each connected to multiple rotating mechanisms 18. Each rotating mechanism 18 is equipped with an electric motor, but the specific configuration of the rotating mechanisms 18 is not particularly limited. When the multiple rotating mechanisms 18 rotate the multiple wafer chucks 25A, 25B around their respective axes while the multiple wafer chucks 25A, 25B are holding the edge portion of the stacked wafer Ws, the vertically positioned stacked wafer Ws rotates around the wafer rotation axis Cr.
[0041] Two of the four or more wafer chucks 25A and 25B, namely, two wafer chucks 25A and 25B, are rotated by two rotation mechanisms 18 fixed to the first base 40A. The other two rotation mechanisms 18 for rotating the other two of the four or more wafer chucks 25A and 25B are fixed to the second base 40B.
[0042] The material application device 1 includes a first chuck moving mechanism 37A and a second chuck moving mechanism 37B for moving the plurality of wafer chucks 25A and 25B and the plurality of rotation mechanisms 18 in a direction approaching the wafer rotation axis Cr and in a direction away from the wafer rotation axis Cr. The first chuck moving mechanism 37A and the second chuck moving mechanism 37B are composed of actuators such as air cylinders.
[0043] The first chuck moving mechanism 37A is connected to the first base 40A and is configured to move the two rotation mechanisms 18 and the two wafer chucks 25A and 25B fixed to the first base 40A. The second chuck moving mechanism 37B is connected to the second base 40B and is configured to move the two rotation mechanisms 18 and the two wafer chucks 25A and 25B fixed to the second base 40B.
[0044] The chuck moving mechanisms 37A and 37B move the plurality of wafer chucks 25A and 25B in a direction approaching the wafer rotation axis Cr, thereby holding the edge portions of the stacked wafers Ws by the plurality of wafer chucks 25A and 25B. Further, the chuck moving mechanisms 37A and 37B move the plurality of wafer chucks 25A and 25B in a direction away from the wafer rotation axis Cr, thereby releasing the plurality of wafer chucks 25A and 25B from the edge portions of the stacked wafers Ws.
[0045] In this embodiment, the application of the filler to the edge portion of the stacked wafer Ws is performed while the stacked wafer Ws rotates in a vertical posture. More specifically, while the edge portions of the stacked wafer Ws are held by the wafer chucks 25A and 25B, the plurality of rotation mechanisms 18 rotate the plurality of wafer chucks 25A and 25B about their axes, whereby the stacked wafer Ws rotates about the wafer rotation axis Cr. The coating module 3 is located above the stacked wafer Ws. The filler is discharged from the coating module 3 toward the edge portion of the stacked wafer Ws.
[0046] FIG. 6 is an enlarged view seen from the direction indicated by arrow A in FIG. 5. As shown in FIG. 6, the stacked wafer Ws applied to this embodiment has a configuration in which the first wafer W1 and the second wafer W2 are bonded together. There is a gap G between the edge portion E1 of the first wafer W1 and the edge portion E2 of the second wafer W2. This gap G is formed over the entire circumference of the stacked wafer Ws. The coating module 3 is located above the gap G and fills the gap G with the filler by discharging the filler toward the gap G.
[0047] As shown in FIG. 5, the curing device 4 is arranged on the downstream side of the coating module 3 in the rotation direction of the stacked wafer Ws and is configured to cure the filler applied to the stacked wafer Ws by the coating module 3. The curing of the filler by the curing device 4 is performed while rotating the stacked wafer Ws. When the application of the filler is completed, the operation control unit 10 gives a command to the rotation mechanism 18 to stop the rotation of the wafer chucks 25A and 25B, thereby stopping the rotation of the stacked wafer Ws.
[0048] The application of the filler to the stacked wafer Ws using the material application device 1 described with reference to FIGS. 5 and 6 can be performed according to the embodiment shown in the flowchart of FIG. 3 or the flowchart of FIG. 4.
[0049] Figure 7 is a front view showing yet another embodiment of the material coating apparatus 1. The configuration and operation of this embodiment, which are not specifically described, are the same as those of the embodiment described with reference to Figures 5 and 6, so redundant descriptions are omitted. In this embodiment, the load measuring device 21 is not incorporated into the wafer chuck 25B, but is positioned between a plurality of lower wafer chucks 25B. The load measuring device 21 is fixed on a support member 45. When the stacked wafer Ws is held in the wafer chucks 25A and 25B, as shown in Figure 7, the edge portion of the stacked wafer Ws is away from the load measuring device 21.
[0050] As shown in Figure 8, after the coating of the filler material from the coating module 3 onto the stacked wafer Ws is completed, and before the weight of the stacked wafer Ws is measured, the operation control unit 10 commands the rotation mechanism 18 to stop the rotation of the multiple wafer chucks 25A and 25B, thereby stopping the rotation of the stacked wafer Ws. Furthermore, the operation control unit 10 commands the chuck movement mechanisms 37A and 37B to move the multiple wafer chucks 25A and 25B slightly away from the wafer rotation axis Cr. As a result, the edge portion of the stacked wafer Ws is placed on the load measuring device 21. The load measuring device 21 can measure the weight of the stacked wafer Ws. The load measuring device 21 is electrically connected to the coating amount calculator 22. The load measuring device 21 measures the weight of the stacked wafer Ws, and the measured weight is transmitted from the load measuring device 21 to the coating amount calculator 22.
[0051] The coating amount calculator 22 is configured to calculate the amount of filler applied to the laminated wafer Ws by acquiring a first weight measurement value output from the load measuring device 21 before the filler is applied to the laminated wafer Ws, acquiring a second weight measurement value output from the load measuring device 21 after the filler is applied to the laminated wafer Ws, and subtracting the first weight measurement value from the second weight measurement value.
[0052] Figure 9 is a flowchart showing one embodiment of applying a filler material F to a stacked wafer Ws of filler material using a material coating apparatus 1 described with reference to Figures 7 and 8. In step 301, the stacked wafer Ws is transported to the wafer holding section 2 by a transport robot (not shown). The chuck moving mechanisms 37A and 37B move the plurality of wafer chucks 25A and 25B toward the wafer rotation axis Cr, and the plurality of load measuring devices 21 incorporated in the plurality of lower wafer chucks 25B support the edge portion of the stacked wafer Ws. The plurality of upper wafer chucks 25A are in contact with the edge portion of the stacked wafer Ws, but do not hold the edge portion of the stacked wafer Ws.
[0053] In step 302, the load measuring device 21 outputs a first weight measurement. The coating amount calculator 22 obtains the first weight measurement from the load measuring device 21. In step 303, the operation control unit 10 gives a command to the rotation mechanism 18 to rotate the plurality of wafer chucks 25A, 25B and the stacked wafer Ws by the rotation mechanism 18, and gives a command to the coating module 3 to coat the filler F onto the edge portion of the stacked wafer Ws.
[0054] In step 304, the operation control unit 10 commands the coating module 3 to finish coating the edges of the stacked wafer Ws after a predetermined time has elapsed. Furthermore, the operation control unit 10 commands the rotation mechanism 18 to stop the rotation of the stacked wafer Ws. In step 305, the operation control unit 10 commands the chuck movement mechanisms 37A and 37B to move the multiple wafer chucks 25A and 25B slightly away from the wafer rotation axis Cr. As a result, the edges of the stacked wafer Ws are placed on the load measuring device 21. In step 306, the load measuring device 21 outputs a second weight measurement. The coating amount calculator 22 obtains the second weight measurement from the load measuring device 21. In step 307, the coating amount calculator 22 calculates (determines) the amount of filler F coated on the stacked wafer Ws by subtracting the first weight measurement from the second weight measurement.
[0055] The embodiments described above are intended to enable persons with ordinary skill in the art to implement the present invention. Various modifications of the above embodiments can be made naturally by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments as well. Therefore, the present invention is not limited to the embodiments described, but is to be interpreted in the broadest sense according to the technical idea defined by the claims.
[0056] The present invention can be used in a material coating apparatus and a material coating method for coating the edges of a stacked wafer, which is composed of multiple wafers bonded together, and is particularly useful in a technique for measuring the amount of filler coated on the edges of a stacked wafer.
[0057] Ws Stacked wafer F Filler 1 Material coating device 2 Wafer holder 3 Coating module 4 Curing device 10 Operation control unit 12 Wafer stage 15 Rotating shaft 18 Rotating mechanism 21 Load measuring device 22 Coating amount calculator 25A Upper wafer chuck 25B Lower wafer chuck 37A First chuck movement mechanism 37B Second chuck movement mechanism 40A First base 40B Second base 45 Support member
Claims
1. A material coating apparatus for coating the edge portion of a stacked wafer, comprising: a wafer holding section for holding the stacked wafer; a rotation mechanism for rotating the wafer holding section to rotate the stacked wafer about a predetermined wafer rotation axis; a coating module for coating the edge portion of the stacked wafer on the wafer holding section rotated by the rotation mechanism; a load measuring device for measuring the weight of the stacked wafer; and a coating amount calculator for acquiring a first weight measurement value output from the load measuring device before the filler is coated on the stacked wafer, acquiring a second weight measurement value output from the load measuring device when the filler is coated on the stacked wafer or after the filler is coated on the stacked wafer, and calculating the amount of the filler coated on the stacked wafer by subtracting the first weight measurement value from the second weight measurement value.
2. The material coating apparatus according to claim 1, wherein the load measuring device supports the wafer holding portion.
3. The material coating apparatus according to claim 1, wherein the wafer holding section comprises a plurality of roller chucks, and the load measuring device comprises a plurality of load measuring devices each supporting the plurality of roller chucks.
4. The material coating apparatus according to claim 1, wherein the wafer holding section comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafers in a vertical position, and the load measuring device comprises a plurality of load measuring devices attached to each of the plurality of lower roller chucks.
5. The material coating apparatus according to claim 1, wherein the wafer holding section comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafers in a vertical position, and the load measuring instrument is positioned between the plurality of lower roller chucks.
6. The material coating apparatus according to claim 1, wherein the coating amount calculator is configured to acquire the second weight measurement value output from the load measuring device when the filler is being coated onto the laminated wafer, calculate the amount of the filler coated onto the laminated wafer by subtracting the first weight measurement value from the second weight measurement value, and determine the coating endpoint when the amount of the filler reaches a predetermined filling threshold.
7. A material coating method for coating the edge portion of a stacked wafer, comprising: holding the stacked wafer with a wafer holder; rotating the wafer holder with a rotation mechanism to rotate the stacked wafer around a predetermined wafer rotation axis; coating the edge portion of the rotating stacked wafer from a coating module; obtaining a first weight measurement value output from a load measuring device for measuring the weight of the stacked wafer before the filler is coated on the stacked wafer; obtaining a second weight measurement value output from the load measuring device when the filler is coated on the stacked wafer or after the filler is coated on the stacked wafer; and calculating the amount of the filler coated on the stacked wafer by subtracting the first weight measurement value from the second weight measurement value.
8. The material coating method according to claim 7, wherein the load measuring device supports the wafer holding portion.
9. The material coating method according to claim 7, wherein the wafer holding section comprises a plurality of roller chucks, and the load measuring device comprises a plurality of load measuring devices each supporting the plurality of roller chucks.
10. The material coating method according to claim 7, wherein the wafer holding section comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafers in a vertical position, and the load measuring device comprises a plurality of load measuring devices attached to each of the plurality of lower roller chucks.
11. The material coating method according to claim 7, wherein the wafer holding section comprises a plurality of upper roller chucks and a plurality of lower roller chucks for holding the stacked wafers in a vertical position, and the load measuring device is positioned between the plurality of lower roller chucks.
12. The material coating method according to claim 7, wherein the second weight measurement is a measurement output from the load measuring instrument when the filler is being coated onto the laminated wafer, and further comprises determining a coating endpoint where the amount of the filler reaches a predetermined filling threshold.