Wafer adsorption and holding method and wafer adsorption and holding apparatus

Abstract

It adheres to wafers with warping with high accuracy. [Solution] The process includes the steps of: attaching an adhesive tape 4 to the first surface 2a of a wafer 1 on which a thermosetting resin part 3 is provided; positioning the wafer 1 on the chuck table 21 such that the tape surface 4b to which the adhesive tape 4 is attached is in contact with the chuck table 21; pressing the pressed portion 2c of the second surface 2b toward the chuck table 21 with a pusher 25 while the adhesive tape 4 is adsorbed to the chuck table 21; and releasing the pressure from the pusher 25. The adhesive tape 4 is sized to extend beyond the wafer 1 and to cover the adsorption holding area 21a of the chuck table 21.

Description

Technical Field

[0001] The present invention relates to a wafer suction holding method and a wafer suction holding apparatus. Background Art

[0002] In a semiconductor device manufacturing process, after a circuit portion is formed on a first surface of a wafer, there is a step of polishing a second surface of the wafer. In this case, after the shape of the wafer such as warpage is corrected, the wafer is conveyed to a back grinder, which is a grinding apparatus, and subjected to ultra-thinning processing at high speed and with high precision.

[0003] A conveying apparatus that conveys wafers to a back grinder, which is a grinding apparatus, includes, for example, a wafer conveying and holding apparatus as disclosed in Patent Document 1. This wafer conveying and holding apparatus includes a chuck table that suction-holds a wafer, and a conveying mechanism that conveys a wafer to be conveyed to the chuck table.

[0004] The chuck table includes a suction holding region that suction-holds a wafer. The conveying mechanism includes a conveying arm and a holding pad. The holding pad includes an inner peripheral pad and an outer peripheral pad. The inner peripheral pad suction-holds the central region of the wafer. The outer peripheral pad presses the outer peripheral region of the wafer that is suction-held by the chuck table.

[0005] The wafer conveying and holding apparatus conveys a wafer to the chuck table with the holding pad, and then presses the outer peripheral region of the wafer with the outer peripheral pad while suction-holding the wafer with the chuck table. This corrects the warpage of the wafer. After that, the wafer is ground. Prior Art Literature Patent Literature

[0006] Patent Document 1 Japanese Patent No. 6771405 Summary of the Invention [Problems that the invention aims to solve]

[0007] As wafers increase in diameter and become thinner, they tend to deform, such as warping. If warping or other deformation remains in the wafer, the negative pressure necessary for suction and holding will not be formed between the wafer and the chuck table, and sufficient suction force will not be obtained.

[0008] In particular, in EMC (Epoxy Molding Compound) wafers where a thermosetting resin portion is provided on the surface on which the circuit is formed, the presence of the thermosetting resin portion makes them prone to deformation such as warping. [Means for solving the problem]

[0009] A wafer adsorption and holding method that solves the above problems comprises the steps of: attaching an adhesive tape to the first surface of a wafer having opposing first and second surfaces; placing the wafer on the chuck table such that the tape surface on the first surface side to which the adhesive tape is attached is in contact with the chuck table; pressing the pressed portion, which is the outer peripheral region of the second surface, toward the chuck table with a pusher while adsorbing the adhesive tape to the chuck table; and releasing the pressure from the pusher, wherein the adhesive tape is large enough to extend beyond the wafer and to cover the adsorption and holding area of ​​the chuck table.

[0010] A wafer adsorption and holding device that solves the above problems comprises a chuck table having opposing first and second surfaces and adsorbing a wafer to which adhesive tape is attached via the adhesive tape, and a pusher that presses the outer peripheral region of the second surface against the chuck table, wherein the adhesive tape is sized to extend beyond the first surface and to cover the adsorption and holding region of the chuck table. [Effects of the Invention]

[0011] According to the present invention, even wafers with significant deformation can be held by suction on the chuck table. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a cross-sectional view of an EMC wafer. [Figure 2] Figure 2 is a schematic diagram showing the configuration of the wafer processing system according to the embodiment. [Figure 3] Figure 3 is a schematic diagram of a wafer suction and holding device. [Figure 4] Figure 4 is a schematic diagram illustrating the size relationship between the EMC wafer and the chuck table. [Figure 5] Figure 5 is a process diagram illustrating the wafer processing steps. [Figure 6] Figure 6 is a schematic diagram showing an EMC wafer with adhesive tape attached. [Figure 7] Figure 7 is a schematic diagram showing the state of adhesive tape after it has been cut to the appropriate size. [Figure 8] Figure 8 is a schematic diagram showing the state in which an EMC wafer is transported to the upper side of the chuck table. [Figure 9] Figure 9 is a schematic diagram showing the state in which an EMC wafer is pressed against a pusher. [Figure 10] Figure 10 is a schematic diagram showing the state in which an EMC wafer is being ground. [Modes for carrying out the invention]

[0013] Embodiments of a wafer adsorption and holding method and a wafer adsorption and holding apparatus will be described with reference to Figures 1 to 10. (Wafer 1) As shown in Figure 1, an example of a wafer transported by a wafer adsorption and holding device according to an embodiment of the present invention will be described with reference to Figure 1. This wafer 1 is an EMC (Epoxy Molding Compound) wafer.

[0014] The wafer 1 includes a base 2 and a thermosetting resin portion 3. The base 2 is a silicon wafer. The base 2 may also be a wafer made of silicon carbide, sapphire, gallium nitride, gallium oxide, gallium arsenide, or the like. The base 2 includes a first surface 2a and a second surface 2b. Hereinafter, the first surface 2a side may be referred to as downward or the lower side, and the second surface 2b side may be referred to as upward or the upper side. The first surface 2a is a back surface as an example. The first surface 2a is a surface to which an adhesive tape 4 is attached as an example. The second surface 2b is a front surface as an example. A circuit portion is formed on the second surface 2b by an integrated circuit or the like. A thermosetting resin portion 3 sealed with thermosetting resin is formed on the second surface 2b. The upper surface of the thermosetting resin portion 3 is a resin surface 3a. Among thermosetting resins, a resin excellent in electrical insulation, mechanical strength, adhesiveness, moisture resistance, chemical resistance, and moldability is used. An epoxy resin is taken as an example of the thermosetting resin. In addition, a silicone resin, a polyimide resin, a phenol resin, or the like can be used as the thermosetting resin. Thermosetting resin shrinks during cooling or the like. For this reason, deformation such as concavely warping downward as a whole often occurs in the wafer 1. The thermosetting resin portion 3 is ground and thinned.

[0015] The thermosetting resin portion 3 has a smaller diameter than the base 2. The second surface 2b of the base 2 is exposed in a region outside the thermosetting resin portion 3. This exposed portion is an outer peripheral region of the second surface 2b. The exposed portion functions as a pressed portion 2c that a pusher 25 (see FIG. 3) abuts against when correcting deformation of the wafer 1. Note that the pusher 25 may abut against a portion other than the pressed portion 2c when correcting deformation of the wafer 1.

[0016] (Adhesive tape 4) The adhesive tape 4 used herein is, for example, a resin tape. The adhesive tape 4 is a resin tape having properties that make it easier to conform to the mounting surface 21s of the chuck table 21 than to the wafer 1. Examples of the adhesive tape 4 include a PET (polyethylene terephthalate) tape, a PO (polyolefin-based) tape, and an elastomer tape. The adhesive tape 4 includes a base material and an adhesive layer provided on one surface of the base material. As one example, irradiation with ultraviolet rays reduces the adhesive force of the adhesive tape 4, making it easier to peel off from the wafer 1.

[0017] The thickness of the adhesive tape 4 is not particularly limited as long as it has sufficient adhesive force to the wafer 1. For example, the lower limit of the total thickness, which is the overall thickness, is 50 µm or more. The lower limit is preferably 80 µm or more, for example. If the thickness is smaller than the lower limit, sufficient adhesive force cannot be obtained, making it difficult to correct deformation of the wafer 1. The upper limit of the total thickness, which is the overall thickness, of the adhesive tape 4 is, for example, 600 µm or less. The upper limit is preferably 200 µm or less, for example. If the thickness of the adhesive tape 4 is larger than the upper limit, it becomes difficult to peel off from the wafer 1.

[0018] The adhesive tape 4 is, for example, circular like the wafer 1. The shapes of the wafer 1 and the adhesive tape 4 are not limited to circular, and may be polygons such as triangle, quadrangle, pentagon, hexagon, etc. The adhesive tape 4 has a larger diameter than the outer diameter of the wafer 1. The adhesive tape 4 has a larger diameter than the base 2. The adhesive tape 4 has a larger diameter than the first surface 2a of the base 2. That is, the outer peripheral end 4a of the adhesive tape 4 protrudes from the outer peripheral end 2d of the base 2.

[0019] (Processing system 10 for wafer 1) As shown in FIG. 2, the processing system 10 for a wafer 1 includes a tape attaching device 11, a wafer suction holding device 12, a grinding device 13, and a controller 14. Note that the tape attaching device 11 may be provided in a device outside the processing system 10 for the wafer 1.

[0020] The tape application device 11 includes a tape supply unit that supplies adhesive tape 4, a tape application unit that adheres the adhesive tape 4 to the first surface 2a of the wafer 1, and a tape cutting unit that cuts the adhesive tape 4.

[0021] The tape supply unit supplies the required amount of adhesive tape 4 from the raw material roll to the tape bonding unit. The tape bonding section includes an adhesive roller and the like for pressing the adhesive layer of the adhesive tape 4 against the base 2. The tape bonding section places the first surface 2a of the wafer 1 and the adhesive layer of the adhesive tape 4 facing each other in the raw roll of adhesive tape 4 fed from the tape supply section. The tape bonding section bonds the adhesive tape 4 to the first surface 2a of the base 2 using the adhesive roller.

[0022] The tape cutting section is equipped with a cutter. The cutter cuts the supplied raw material into a circular shape to match the size of wafer 1. As a result, the adhesive tape 4 is cut to a size that is larger in diameter than the diameter of base 2, larger in diameter than the suction holding area 21a of the chuck table 21, and smaller in diameter than the non-suction holding area 21b (see Figure 4). For example, the diameter of the adhesive tape 4 is 2 mm larger than the diameter of base 2.

[0023] Note that the diameter of the adhesive tape 4 is not limited to the example above; it should be larger than the diameter of the base 2 and not get caught in the grinding wheel 13b during grinding. Also, the diameter of the adhesive tape 4 should be large enough not to flap around during grinding (see Figure 10).

[0024] The wafer suction and holding device 12, as will be described in detail later, sucks up the wafer 1 to which the adhesive tape 4 is attached to the first surface 2a and transports it to the chuck table 21. The wafer suction and holding device 12 sucks up the resin surface 3a of the thermosetting resin part 3 and transports it to the chuck table. Here, the wafer 1 is held by the chuck table 21 via the adhesive tape 4, with the tape surface 4b being sucked up.

[0025] The grinding device 13 thins the thermosetting resin part 3 by grinding it. Specifically, the grinding device 13 includes a grinding head 13a and a grinding wheel 13b. The grinding head 13a grinds and thins the thermosetting resin part 3 by rotating while the grinding wheel 13b is in contact with the surface of the thermosetting resin part 3 (see Figure 10). After this, the wafer 1 is transported to a dicing device or the like.

[0026] The controller 14 controls the tape application device 11, the wafer suction and holding device 12, the grinding device 13, etc. For example, the controller 14 is a computer. The controller 14 includes communication devices, input devices, output devices, storage devices, a processor, etc. Note that this hardware configuration is just an example, and it can be implemented with other hardware.

[0027] Communication devices are interfaces that establish communication paths with other devices and perform data transmission and reception. Examples of communication devices include network interface cards and wireless interfaces. Input devices are devices that accept input of various types of information. Examples of input devices include touch panels, mice, and keyboards. Output devices are displays that show various types of information, speakers, etc. Storage devices store data, programs, etc., necessary to perform various functions of the control device. Examples of storage devices include ROM, RAM, hard disks, and SSDs.

[0028] A processor controls various processes using programs and data stored in memory. Examples of processors include CPUs and MPUs. A processor loads programs stored in ROM or other memory into RAM and executes various instructions corresponding to various processes. For example, when an application program is launched, the processor executes instructions corresponding to each process.

[0029] A processor is not limited to performing software processing for all the processes it executes. For example, a processor may have dedicated hardware circuits (e.g., application-specific integrated circuits: ASICs) that perform hardware processing for at least some of the processes it executes. That is, a processor can be configured as a circuit including (1) one or more processors that operate according to a computer program (software), (2) one or more dedicated hardware circuits that perform at least some of the various processes, and (3) a combination of (1) and (2). A processor includes a CPU and memory such as RAM and ROM, where memory stores program code or instructions configured to cause the CPU to execute processes. Memory includes any available medium that can be accessed by a general-purpose or dedicated computer.

[0030] (Wafer suction and holding device 12) As shown in Figure 3, the wafer suction and holding device 12 comprises a chuck table 21, a transport mechanism 22, and a holding pad 23.

[0031] The chuck table 21 is a disc-shaped table. On the chuck table 21, the mounting surface 21s on which the wafer 1 is placed comprises an adsorption holding area 21a and a non-adsorption holding area 21b. The mounting surface 21s on which the wafer 1 is placed is the surface facing the tape surface 4b of the wafer 1.

[0032] The adsorption and holding region 21a is composed of a porous section. The adsorption and holding region 21a has multiple suction holes. The multiple suction holes are connected to a vacuum line for wafer suction. A pressure gauge, a valve, and a vacuum pump are connected to the vacuum line for wafer suction in that order.

[0033] The non-adsorption holding area 21b is located on the outer periphery of the chuck table 21. The non-adsorption holding area 21b has a ring shape on the outer periphery of the chuck table 21. The non-adsorption holding area 21b is not the area that adsorbs the wafer 1. The non-adsorption holding area 21b is the part that supports the outer edge 2d of the base 2 of the wafer 1. The non-adsorption holding area 21b is also the part that supports the outer edge 4a of the adhesive tape 4 that extends beyond the base 2 of the wafer 1.

[0034] The transport mechanism 22 includes a transport arm 22a that can rotate and move vertically. The base end of the transport arm 22a is fixed to, for example, a robot arm (not shown). The other end of the transport arm 22a is provided with a holding pad 23 capable of adsorbing and holding the wafer 1. The transport arm 22a transports the wafer 1, to which the adhesive tape 4 has been attached, from the tape application device 11 to the chuck table 21.

[0035] The retaining pad 23 comprises an inner circumferential pad 24 and a pusher 25. The inner peripheral pad 24 has a substantially circular, dish-shaped suction surface 24a that opens downwards. The suction surface 24a adsorbs the resin surface 3a of the wafer 1. For example, the suction surface 24a adsorbs the central region of the resin surface 3a.

[0036] The pusher 25 is movable vertically relative to the inner circumferential pad 24. The pusher 25 has a ring shape. The pusher 25 contacts the pressed portion 2c of the wafer 1. The pusher 25 is moved vertically by a drive unit 26 such as a pressurizing cylinder. The surface of the pusher 25 may be provided with a pad material made of rubber, soft resin, or the like.

[0037] The drive unit 26 is connected to a rod 25a that moves the pusher 25 up and down. The rod 25a is located on the central axis of the chuck table 21. The pusher 25 and the rod 25a are connected via a connecting part 25b.

[0038] Here, we will use Figure 4 to explain the relative sizes of the chuck table 21 and the wafer 1. In wafer 1, the diameter of the base 2 is D1. The diameter of the thermosetting resin part 3 is D2. The diameter of the adhesive tape 4 is D3. In addition, in the chuck table 21, the diameter of the adsorption holding area 21a is D4. The diameter of the non-adsorption holding area 21b is D5.

[0039] The diameter D1 of base 2 is, for example, 300 mm. The diameter D2 of thermosetting resin part 3 is, for example, 280-285 mm. The diameter D3 of adhesive tape 4 is, for example, 302 mm. The diameter D4 of adsorption holding area 21a is, for example, 297 mm. The thickness T1 of base 2 is, for example, 775 μm. The thickness T2 of thermosetting resin part 3 is, for example, 1105 μm before grinding and 775 μm-100 μm after grinding.

[0040] The diameter D2 of the thermosetting resin part 3 is smaller than the diameter D1 of the base 2. As a result, a pressed portion 2c is formed on the second surface 2b. The diameter D3 of the adhesive tape 4 is greater than the diameter D1 of the base 2. As a result, the outer edge 4a of the adhesive tape 4 extends beyond the base 2.

[0041] The diameter D3 of the adhesive tape 4 is larger than the diameter D4 of the adsorption holding area 21a. This allows the adhesive tape 4 to cover the entire adsorption holding area 21a. The diameter D3 of the adhesive tape 4 is smaller than the diameter D5 of the non-adhesive holding area 21b. As a result, the outer edge 4a of the adhesive tape 4 is supported by the non-adhesive holding area 21b. The diameter D1 of the base 2 is larger than the diameter D4 of the adhesive holding area 21a.

[0042] (Wafer processing method) Figure 5 shows the processing method for wafer 1. In step 101, wafer 1 is prepared with a thermosetting resin part 3 provided on the second surface 2b of the base 2. In step 102, the tape bonding section of the tape bonding device 11 presses and bonds the adhesive layer of the adhesive tape 4 to the first surface 2a of the base 2 (see Figure 6). In step 103, the tape cutting section of the tape bonding device 11 cuts the adhesive tape 4 to a size whose diameter is larger than the diameter D1 of the base 2, larger than the diameter D4 of the suction holding area 21a of the chuck table 21, and smaller than the diameter D5 of the non-suction holding area 21b (see Figures 6 and 7). As an example, the tape cutting section cuts the adhesive tape 4 at the position of line L such that the diameter D3 of the adhesive tape 4 is larger than the diameter D1 of the base 2 by about 2 mm.

[0043] In step 104, the resin surface 3a of the wafer 1 is adsorbed by the inner peripheral pad 24 of the holding pad 23 of the wafer adsorption holding device 12. For example, the wafer 1 is inverted from a state where the tape surface 4b is facing upwards to a state where the resin surface 3a is facing upwards. Then, the wafer 1 is in a state where the resin surface 3a is adsorbed by the inner peripheral pad 24. The transport mechanism 22 then transports the wafer 1 to the chuck table 21 (see Figure 8). The wafer 1 is placed on the adsorption holding area 21a via the adhesive tape 4. The wafer 1 is placed so that its center coincides with the central axis of the chuck table 21. After that, the adsorption of the wafer 1 by the inner peripheral pad 24 is released. The base 2 of the wafer 1 is slightly larger than the adsorption holding area 21a, and the outer peripheral edge 4a of the adhesive tape 4 is supported in the non-adsorption holding area 21b. The outer edge 4a of the adhesive tape 4 does not extend beyond the non-adhesive holding area 21b (see Figure 8). In other words, this is a state in which the adhesive tape 4 covers the entire adhesive holding area 21a.

[0044] In step 105, the chuck table 21 vacuum-adsorbs the wafer 1. Simultaneously, the pusher 25 descends toward the chuck table 21, pressing the pressed portion 2c, which is located on the outer circumference of the wafer 1, against the chuck table 21. For example, the pusher 25 presses the pressed portion 2c with 40 kg of force. Alternatively, the pusher 25 may press the pressed portion 2c so that the outer edge 4a of the adhesive tape 4 contacts the non-adsorbent holding area 21b, even if it does not press the pressed portion 2c against the chuck table 21. In other words, the pusher 25 may press the outer circumference of the wafer 1 so that the adhesive tape 4 covers the adsorbent holding area 21a.

[0045] Because the wafer 1 has a thermosetting resin portion 3 on the base 2, deformation such as warping, where the second surface 2b side is concave, may occur. In other words, when the wafer 1 is warped or deformed, the outer edge 2d of the base 2 separates from the mounting surface 21s of the chuck table 21 and floats. In such cases, the amount of floating height varies depending on the location. Furthermore, the thinner the wafer 1 becomes, the easier and larger the deformation becomes. In such cases, it may be difficult to correct the deformation of the wafer 1 simply by pressing the pressed portion 2c with the pusher 25 while holding it in place with the chuck table 21.

[0046] In this regard, the wafer 1 is adsorbed to the chuck table 21 via adhesive tape 4. The adhesive tape 4 has properties that make it easier to conform to the mounting surface 21s of the chuck table 21 than the wafer 1, and covers the entire adsorption holding area 21a. Therefore, the adsorption holding area 21a can attract the adhesive tape 4 without leakage. A negative pressure is reliably formed between the chuck table 21 and the adhesive tape 4. This corrects deformations such as warping of the wafer 1 to which the adhesive tape 4 is attached. In this way, the wafer 1 is adsorbed and held on the mounting surface 21s of the chuck table 21 with high accuracy through the cooperation of adsorption by the chuck table 21 via adhesive tape 4 and pressing by the pusher 25 (see Figure 9).

[0047] Furthermore, the suction by the chuck table 21 may be performed prior to the pressing by the pusher 25, or the pressing by the pusher 25 may be performed prior to the suction by the chuck table 21.

[0048] Subsequently, in step 106, the wafer suction and holding device 12 releases the pressure applied by the pusher 25 by raising the pusher 25. Next, the wafer suction and holding device 12 retracts the inner peripheral pad 24 from the wafer 1. The chuck table 21 continues to hold the wafer 1. Because the wafer 1 is held to the chuck table 21 via the adhesive tape 4, a flat state with deformation corrected is maintained.

[0049] The controller 14 detects whether the wafer 1 is securely held in place based on the pressure data input from the pressure gauge. For example, the controller 14 determines that the wafer 1 is held in place on the chuck table 21 when the pressure indicated by the pressure data input from the pressure gauge is above a threshold. The controller 14 determines that the wafer 1 is not held in place when the pressure is below the threshold. If the wafer 1 is not held in place on the chuck table 21, the controller 14 prevents the next grinding process from being performed.

[0050] In step 107, the wafer 1 is held in place by the chuck table 21, and the resin surface 3a is ground by the grinding device 13 using the grinding wheel 13b (see Figure 10). The diameter of the adhesive tape 4 is only 2 mm larger than the diameter of the base 2. Therefore, it is possible to prevent the outer edge 4a of the adhesive tape 4 from getting caught in the grinding wheel 13b during grinding. It is also possible to suppress flapping of the outer edge 4a during grinding. As a result, the thermosetting resin part 3 is made thinner. Since the wafer 1 is securely held in place along the chuck table 21 before grinding, the resin surface 3a can be ground to a uniform thickness during grinding.

[0051] (Effects of the embodiment) (1) The wafer 1 is attached to the suction holding area 21a of the chuck table 21 via the adhesive tape 4, with the tape surface 4b adhering to it. The adhesive tape 4 has properties that make it easier to conform to the shape of the mounting surface 21s of the chuck table 21 than the wafer 1, and is sized to extend beyond the first surface 2a and cover the suction holding area 21a. Therefore, the wafer 1 is reliably attracted to the chuck table 21 via the adhesive tape 4, and the pressed portion 2c of the wafer 1 is pressed by the pusher 25. As a result, the shape of the wafer 1 is corrected to conform to the mounting surface 21s of the chuck table 21. Therefore, a negative pressure is reliably formed between the chuck table 21 and the adhesive tape 4. As a result, the wafer 1 can be reliably attracted and held on the mounting surface 21s.

[0052] (2) In particular, wafers 1 provided with the thermosetting resin part 3 are prone to deformation such as warping, where the second surface 2b side is concave. Even with wafers 1 equipped with the thermosetting resin part 3, warping and other deformations of the wafer 1 can be corrected by attaching adhesive tape 4 to the first surface 2a, and while the tape surface 4b is adsorbed to the mounting surface 21s of the chuck table 21, the pressed portion 2c of the wafer 1 from the second surface 2b side is pressed with the pusher 25. As a result, the wafer 1 can be reliably held in place by suction on the mounting surface 21s.

[0053] (3) The outer peripheral end 4a of the adhesive tape 4 that extends beyond the base 2 is supported by the non-adhesive holding area 21b. Therefore, for example, when grinding the resin surface 3a, it is possible to prevent the outer peripheral end 4a from interfering with the grinding process.

[0054] (4) Because the adhesive tape 4 is made of resin, it is possible to construct an adhesive tape 4 that conforms more easily to the shape of the mounting surface 21s of the chuck table 21 than to the wafer 1. (5) For example, if the outer edge 2d of the base 2 is located inside the non-adsorption holding area 21b, an area is provided between the outer edge 2d of the base 2 and the outer edge of the adsorption holding area 21a where only the adhesive tape 4 is adsorbed. In such an area, because the base 2 is absent, the adhesive tape 4 is more likely to bend and may be attracted too strongly to the adsorption holding area 21a, causing a gap to form between the adhesive tape 4 and the adsorption holding area 21a, which may lead to a vacuum breach. If the vacuum is breached, the chuck table 21 will no longer be able to adsorb the wafer 1.

[0055] In this respect, the outer peripheral edge 2d of the base 2 is located outside the adsorption holding area 21a of the chuck table 21 and on the non-adsorption holding area 21b. Therefore, it is possible to eliminate the area where only the adhesive tape 4 is adsorbed to the adsorption holding area 21a. As a result, the chuck table 21 can reliably adsorb the wafer 1.

[0056] (6) Before grinding, the wafer 1 has been deformed in such a way that the second surface 2b side is concave. Therefore, the resin surface 3a can be ground to a uniform thickness. (modified version) This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically.

[0057] The adhesive tape is not limited to resin tape, but may also be, for example, a metal tape, as long as it has properties that make it easier to conform to the mounting surface 21s of the chuck table 21 than to the wafer 1.

[0058] The diameter D1 of the base may be smaller than the diameter D4 of the suction holding area 21a. Even in this case, if the diameter D3 of the adhesive tape 4 is made larger than the diameter D4 of the suction holding area 21a, a negative pressure can be reliably formed between the chuck table 21 and the adhesive tape 4.

[0059] When grinding the resin surface 3a, the diameter D3 of the adhesive tape 4 may be larger than the diameter D5 of the non-adhesive holding area 21b, provided that the outer peripheral edge 4a does not interfere with the grinding. • The wafer 1 may not have the thermosetting resin portion 3.

[0060] The size of wafer 1 is not particularly limited, such as 150 mm (6 inches), 200 mm (8 inches), or 300 mm (12 inches). Furthermore, wafer 1 is not limited to a circular wafer; for example, it may be a rectangular wafer. Regardless of the size of wafer 1, the adhesive tape 4 only needs to be large enough to extend beyond the outer edge 2d of the base 2 and cover the adsorption holding area 21a. [Explanation of Symbols]

[0061] Symbol...Part name, D1~D5...Diameter, 1...Wafer, 2...Base, 2a...First surface, 2b...Second surface, 2c...Pressed part, 2d...Outer edge, 3...Thermosetting resin part, 3a...Resin surface, 4...Adhesive tape, 4a...Outer edge, 4b...Tape surface, 10...Processing system, 21...Chuck table, 21a...Adsorption holding area, 21b...Non-adsorption holding area, 21s...Placement surface, 22...Transport mechanism, 22a...Transport arm, 23...Holding pad, 24...Inner pad, 24a...Adsorption surface, 25...Pusher, 25a...Rod, 25b...Connecting part, 26...Drive part.

Claims

1. A wafer having opposing first and second surfaces, comprising the steps of attaching adhesive tape to the first surface, The steps include: placing the wafer on the chuck table such that the tape surface on the first side to which the adhesive tape is attached is in contact with the chuck table; The process involves pressing the area to be pressed, which is the outer peripheral region of the second surface, toward the chuck table using a pusher while the adhesive tape is adsorbed onto the chuck table, The process includes a step of releasing the pressure applied by the pusher, The adhesive tape is sized to extend beyond the wafer and to cover the suction holding area of ​​the chuck table. Method for adsorbing and holding wafers.

2. The second surface of the wafer is provided with a thermosetting resin portion. The pressed portion is formed on the outer circumference of the thermosetting resin portion. The wafer adsorption and holding method according to claim 1.

3. The chuck table has a non-adsorption holding area outside the adsorption holding area, The adhesive tape is sized such that its outer edge is positioned on the non-adhesive holding area. The wafer adsorption and holding method according to claim 1 or 2.

4. The adhesive tape is a resin tape. The wafer adsorption and holding method according to claim 1.

5. The outer edge of the wafer is located outside the adsorption holding area of ​​the chuck table and on the non-adsorption holding area. The wafer adsorption and holding method according to claim 3.

6. A chuck table having opposing first and second surfaces, and which holds a wafer with adhesive tape attached to the first surface via the adhesive tape, The device comprises a pusher that presses the outer peripheral region of the second surface toward the chuck table, The adhesive tape is formed to be large enough to extend beyond the first surface and to cover the suction holding area of ​​the chuck table. Wafer suction and holding device.

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