Method for arranging protective member and method for processing workpiece

Abstract

To dispose a protective member in a predetermined area of a workpiece easily at low cost.SOLUTION: A protective member disposing method is to expose a workpiece partitioned by a plurality of division scheduled lines crossing each other and having devices formed in respective areas on a surface along the division scheduled lines and dispose protective members on the surface, and the method includes: a fusing step of fusing resin by using an injection tool that has a heater and applies heat to resin with the heater to fuse the resin and injects the resin; a disposing step of disposing the fused resin injected from the injection tool onto the devices on the surface of the workpiece; and a solidifying step of solidifying the resin on the surface of the workpiece to dispose the protective members on the surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a method for providing a protective member on a workpiece, and a method for processing a workpiece on which a protective member is provided. [Background technology]

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers, first, a plurality of mutually intersecting planned division lines (streets) are set on the surface of a wafer made of a material such as a semiconductor. Then, devices such as ICs (Integrated Circuits) and LSIs (Large-scale Integration) are formed in each area defined by the planned division lines. The wafer is then divided along the planned division lines to form individual device chips.

[0003] The wafer is divided, for example, by a cutting device equipped with an annular cutting blade (see, for example, Patent Document 1). Alternatively, the wafer is divided by a laser processing device capable of laser processing the wafer, or a plasma etching device capable of plasma etching the wafer (see, for example, Patent Document 2 and Patent Document 3).

[0004] In cutting machines, cutting water is supplied to the cutting blade and workpiece to remove generated heat and cutting chips while cutting the workpiece. However, when the cutting water containing the cutting chips comes into contact with the surface of the workpiece, the cutting chips adhere to the surface of the workpiece, resulting in the problem of contaminating the surface of the workpiece. To address this problem, a tape-like protective member is sometimes attached to the surface of the workpiece, and the workpiece is cut together with the protective member. In this case, contamination is prevented because the cutting water does not come into contact with the surface of the workpiece.

[0005] Furthermore, when a workpiece is laser-processed using a laser processing device, molten material called debris is generated and adheres to the surface of the workpiece. Therefore, a water-soluble protective member is first applied to the entire surface of the workpiece before laser processing. In this case, if the workpiece is subsequently washed, the debris adhered to the protective member can be removed along with the protective member. Furthermore, in a plasma etching device, a protective member (resist film) that exposes the workpiece along the planned dividing line is first applied to the surface of the workpiece, and the exposed portion of the workpiece is then plasma-etched. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-87282 [Patent Document 2] Japanese Patent Application Laid-Open No. 2004-188475 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-108428 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when a workpiece is cut together with its protective member using a cutting device, the material that constitutes the protective member adheres to the cutting edge of the cutting blade, causing the cutting blade to become clogged. Eventually, the cutting resistance increases, and the workpiece cannot be cut properly. Furthermore, with a laser processing device, the protective member may peel off near the processing point due to the impact of the laser processing. Furthermore, plasma etching of the workpiece requires exposure and development processes to form a protective member that precisely exposes a predetermined area on the surface of the workpiece, which requires a lot of effort and cost.

[0008] Furthermore, machining devices are sometimes used to form grooves in pipe-shaped workpieces, but it is not easy to precisely machine such workpieces. One reason for this is that the workpiece is crushed and deformed during machining, resulting in misalignment of the machining position. To address this issue, powdered resin material is filled into the workpiece's communicating holes, melted, and a protective member is placed in the communicating holes to resist deformation of the workpiece. However, the longer the workpiece is and the smaller its inner diameter, the more difficult it becomes to fill the powdered resin material.

[0009] In this way, various problems arise when the protective member is disposed on the workpiece for processing or when the workpiece is processed.

[0010] The present invention has been made in consideration of such problems, and its object is to provide a method for arranging a protective member in a predetermined shape in a predetermined area of ​​a workpiece easily and inexpensively, and a method for processing the workpiece. [Means for solving the problem]

[0011] According to one aspect of the present invention, there is provided a method for disposing a protective member on a surface of a workpiece that is divided by a plurality of mutually intersecting planned dividing lines and has devices formed in each area of ​​the surface, while exposing the workpiece along the planned dividing lines, the method comprising: a melting step of melting the resin using an injection tool that has a heater and heats and melts the resin with the heater while injecting it; a disposing step of disposing the molten resin injected from the injection tool on the devices on the surface of the workpiece; and a solidifying step of solidifying the resin on the surface of the workpiece, thereby disposing the protective member on the surface.

[0012] Preferably, in the disposing step, the molten resin is disposed on the surface of the workpiece while being stretched into a thread-like shape.

[0013] More preferably, the resin is a polyolefin-based resin or a polyester-based resin.

[0014] According to another aspect of the present invention, a workpiece is provided, which is partitioned by a plurality of intended dividing lines that intersect with each other and has devices formed in each of the regions on its surface. A protective member is disposed on the surface while exposing the workpiece along the intended dividing line. A method for processing a workpiece along the planned dividing line is provided, comprising: a melting step of melting the resin using an injection tool having a heater that heats and melts the resin while injecting it; an arrangement step of disposing the molten resin injected from the injection tool on the device on the surface of the workpiece; a solidification step of disposing a protective member on the surface of the workpiece by solidifying the resin on the surface of the workpiece; a processing step of processing an area of ​​the workpiece where the protective member is not disposed after the solidification step; and a removal step of removing the protective member from the workpiece by attaching tape to the protective member of the workpiece from above and lifting the tape from the workpiece after the processing step.

[0015] Preferably, in the disposing step, the molten resin is disposed on the surface of the workpiece while being stretched into a thread-like shape. [Effects of the Invention]

[0019] In one aspect of the present invention, a protective member disposing method and a workpiece processing method use an injection tool having a heater that heats and melts resin and injects it. The resin injected from the injection tool is then disposed on the workpiece and solidified, thereby disposing a protective member on the workpiece. This method eliminates the need to remove the protective member from unnecessary locations, and makes it possible, for example, to dispose the protective member only in a predetermined area on the surface of the workpiece, or to form the protective member into a thread-like shape and dispose it in a communicating hole in a pipe-shaped workpiece.

[0020] Therefore, by not disposing a protective member near the processing point by the cutting blade or laser beam, clogging of the cutting blade caused by cutting the protective member can be prevented, and peeling of the protective member due to the impact of laser processing can also be prevented. Also, the protective member used as a resist film required for plasma etching can be disposed easily and inexpensively without performing exposure and development processes. Furthermore, a protective member with a shape that can be easily disposed in the communicating hole of a pipe-shaped workpiece can be formed.

[0021] Therefore, according to one aspect of the present invention, there are provided a method for easily and inexpensively disposing a protective member in a predetermined shape in a predetermined region of a workpiece, and a method for processing the workpiece. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view schematically showing a workpiece. [Figure 2] 1A to 1C are cross-sectional views schematically illustrating a melting step and a disposing step. [Figure 3] FIG. 3(A) is a cross-sectional view schematically showing a workpiece having a protective member disposed on its surface, and FIG. 3(B) is a cross-sectional view schematically showing an example of a processing step. [Figure 4] FIG. 4(A) is a cross-sectional view schematically showing another example of the processing step, and FIG. 4(B) is a cross-sectional view schematically showing yet another example of the processing step. [Figure 5] Figure 5(A) is a cross-sectional view that schematically shows the first stage of the removal step, Figure 5(B) is a cross-sectional view that schematically shows the protective member with tape attached, and Figure 5(C) is a cross-sectional view that schematically shows the second stage of the removal step. [Figure 6] FIG. 6(A) is a plan view that schematically shows how molten resin is spread, and FIG. 6(B) is a plan view that schematically shows how thread-like resin is disposed. [Figure 7] FIG. 7(A) is an enlarged cross-sectional view schematically showing a workpiece on which a thread-like protective member is disposed, and FIG. 7(B) is a cross-sectional view schematically showing a removing step. [Figure 8] Figure 8(A) is a perspective view schematically showing a workpiece having a communicating hole, and Figure 8(B) is a perspective view schematically showing a workpiece in which a thread-like protective member is arranged in the communicating hole. [Figure 9] Figure 9(A) is a perspective view that schematically shows how a workpiece having a thread-like protective member disposed in a communicating hole is processed, and Figure 9(B) is a perspective view that schematically shows how the thread-like protective member disposed in the communicating hole is pushed out. [Figure 10] Figure 10(A) is a flowchart showing the flow of each step of a protective member disposing method and processing method according to one example, and Figure 10(B) is a flowchart showing the flow of each step of a protective member disposing method and processing method according to another example. DETAILED DESCRIPTION OF THE INVENTION

[0023] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. First, a workpiece on which a protective member is disposed in a protective member disposing method and a workpiece processing method according to this embodiment will be described. Fig. 1 is a perspective view schematically showing a workpiece 1 according to one example.

[0024] The workpiece 1 is, for example, a wafer made of a material such as Si (silicon), SiC (silicon carbide), GaN (gallium nitride), GaAs (gallium arsenide), or other semiconductor, or a substantially disk-shaped substrate made of a material such as sapphire, glass, or quartz.

[0025] A plurality of mutually intersecting planned dividing lines 3 are set on the surface 1a of the workpiece 1. Devices 5 such as ICs (Integrated Circuits) and LSIs (Large Scale Integration) are formed in each area defined by the planned dividing lines 3. When the workpiece 1 is divided along the planned dividing lines 3, individual device chips each equipped with a device 5 can be formed. Cutting of the workpiece 1 along the planned dividing lines 3 is performed by a processing device such as a cutting device, a laser processing device, or a plasma etching device.

[0026] The cutting device is equipped with an annular cutting blade with a grinding wheel on its outer periphery. The grinding wheel of the cutting blade includes abrasive grains made of a material such as diamond, and a binder made of a material such as resin or metal that disperses and fixes the abrasive grains. The cutting device cuts the workpiece 1 by cutting the grinding wheel into the workpiece 1 while rotating the cutting blade, forming dividing grooves along the planned dividing lines 3 and dividing the workpiece 1.

[0027] In the cutting device, cutting water is supplied to the cutting blade and the workpiece 1 when cutting the workpiece 1. The cutting water removes heat generated by cutting and also removes cutting chips generated from the workpiece 1 and the cutting blade during cutting. However, if the cutting water containing the cutting chips comes into contact with the surface 1a of the workpiece 1, problems arise such as contamination of the surface 1a of the workpiece 1 or adhesion of the cutting chips to the device 5, resulting in a decrease in the quality of the device chip.

[0028] Therefore, in the past, a tape-like protective member was attached to the entire surface 1a of the workpiece 1, and the workpiece 1 was cut together with the protective member. In this case, the surface 1a of the workpiece 1 is protected by the protective member, so it is not contaminated by cutting water, etc. However, when the workpiece 1 together with the protective member is cut with a cutting blade, the material that made up the protective member adheres to the grinding wheel part of the cutting blade, causing the cutting blade to become clogged. With a cutting blade in this state, the cutting resistance increases and the workpiece 1 cannot be cut normally.

[0029] Furthermore, the laser processing device that cuts the workpiece 1 by laser processing has the function of focusing a laser beam of a wavelength that is absorbed by the workpiece 1 onto the workpiece 1 to perform ablation processing on the workpiece 1. The laser processing device irradiates the workpiece 1 with a laser beam along the planned division line 3 to form division grooves in the workpiece 1.

[0030] At this time, molten material of the workpiece 1, called debris, is generated and adheres to the surface 1a of the workpiece 1, so the surface 1a of the workpiece 1 is covered with a water-soluble protective material beforehand before laser processing the workpiece 1. The generated debris adheres to the water-soluble protective material, but when the workpiece 1 that has been ablated is washed, the debris is washed away along with the water-soluble protective material, so no debris remains on the workpiece 1.

[0031] However, when a laser beam is focused on the workpiece 1 through a water-soluble protective member, the protective member may partially peel off. This is because if the processing point of the workpiece 1 is covered with a protective member, when the workpiece 1 is partially melted or vaporized by the laser beam and scattered, a strong impact is applied to the protective member that breaks through it. If the protective member partially peels off and the surface 1a of the workpiece 1 is exposed, a problem occurs in that debris adheres to the exposed portion.

[0032] Furthermore, a plasma etching apparatus capable of plasma etching the workpiece 1 supplies plasma etchant gas to the workpiece 1. The etchant gas then partially removes the workpiece 1 to form division grooves along the planned division lines 3. At this time, a resist film must be provided in advance as a protective member on the surface 1a of the workpiece 1 to prevent the etchant gas from acting on areas other than the planned division lines 3. Here, the resist film must precisely expose predetermined areas of this surface 1a.

[0033] To provide a resist film that exposes a predetermined region on the workpiece 1, first, a photosensitive resin material is provided over the entire surface 1a of the workpiece 1, and the resin material is partially altered by irradiating it with light along the planned dividing lines 3 or by irradiating it with light on regions other than the planned dividing lines 3. Then, a developer is applied to the resin material to remove the resin material in the regions that overlap with the planned dividing lines 3, thereby exposing the surface 1a of the workpiece 1 along the planned dividing lines 3.

[0034] Thus, to apply a resist film to the workpiece 1, a photosensitive resin material, a developer, and a cleaning solution are required, and the resin material must be precisely exposed to light. Therefore, plasma etching requires a large amount of money and a long processing time. Furthermore, a complex and expensive exposure device is required.

[0035] Furthermore, the workpiece processed by the processing device is not limited to a plate-like object such as a semiconductor wafer. Figure 8(A) and other figures schematically show a pipe-shaped workpiece 15 having a communicating hole 17. The pipe-shaped workpiece 15 processed by the processing device is formed, for example, with an outer diameter of about 2 mm and an inner diameter of about 1 mm.

[0036] The pipe-shaped workpiece 15 is made of a resin material, glass, or the like, and is flexible and bendable. For example, the workpiece 15 is precisely cut to a predetermined length, or a groove is formed at a specific position. The workpiece 15 is then incorporated into precision machinery as a fluid flow path or used in medical procedures.

[0037] However, it is not easy to precisely machine such a workpiece 15. First, it is difficult to fix the pipe-shaped workpiece 15. Also, when a cutting tool is applied to the workpiece 15, the workpiece 15 may deform and be crushed, resulting in a shift in the machining position. To address this issue, a conventional method has been to fill the communicating holes 17 of the workpiece 15 with a powdered resin material, melt it, and then provide a protective member in the communicating holes 17 to resist deformation. However, the longer the workpiece 15 is and the smaller the inner diameter of the workpiece 15 is, the more difficult it becomes to pack the powdered resin material.

[0038] As described above, various problems arise when a protective member is disposed on the workpiece 1, 15 and used for processing, or when the workpiece 1, 15 is processed. Therefore, in the protective member disposing method and workpiece processing method according to this embodiment, a protective member of a predetermined shape is disposed in a predetermined area on the workpiece 1, 15 so as to prevent various problems caused by the protective member. The protective member disposing method and workpiece processing method according to this embodiment will be described below.

[0039] Fig. 10(A) is a flowchart showing the flow of each step of the method for processing a workpiece according to this embodiment. However, it is not necessary to perform all of the steps shown in Fig. 10(A). Furthermore, the method for disposing a protective member according to this embodiment is included in the method for processing a workpiece shown in Fig. 10(A). Therefore, the method for disposing a protective member will be explained in conjunction with the following explanation of the method for processing a workpiece.

[0040] First, an example will be described in which a protective member is provided on a plate-shaped workpiece 1 shown in Fig. 1 and then processed. That is, the example will be described in which a protective member is provided on the surface 1a of the workpiece 1, which is partitioned by a plurality of mutually intersecting planned division lines 3 and has devices 5 formed in each region of the surface 1a, while the workpiece 1 is exposed along the planned division lines 3 and then processed.

[0041] First, a melting step S10 is performed in which the resin is melted using an injection tool that has a heater and injects the resin while heating and melting it with the heater, and a disposing step S20 is performed in which the molten resin injected from the injection tool is disposed on the device 5 on the surface 1a of the workpiece 1. Figure 2 is a cross-sectional view that schematically shows the melting step S10 and the disposing step S20.

[0042] Here, the injection tool 2 used in the melting step S10 and the disposing step S20 will be described. For example, the injection tool 2 is a glue gun, and has the function of melting and injecting rod-shaped resin 4. An operator holds the injection tool 2 in his / her hand when using it. The main body 6 of the injection tool (glue gun) 2 shown in FIG. 2 includes a grip portion 8a that the operator holds when holding the main body 6, and a trigger 8b on which the fingers of the hand gripping the grip portion 8a are hooked. A path is provided inside the upper end of the main body 6 through which the rod-shaped resin 4 is introduced, melted, and injected.

[0043] More specifically, the main body 6 has a support part 10 at its rear end into which the rod-shaped resin 4 is introduced and supported. The tip of the rod-shaped resin 4 introduced from the inlet of the support part 10 passes through a feed part 12 provided at an outlet provided on the tip side of the support part 10, advances into the external space, and then advances again inside the main body 6 from an inlet 14 on the front side of the main body 6.

[0044] The feeding part 12 is mechanically connected to the trigger 8b, and when the worker's fingers pull the trigger 8b, the feeding part 12 moves forward of the main body 6, the resin 4 is fed forward, and the resin 4 is sent into the inlet 14.

[0045] A heater 16 is housed inside the front side of the main body 6. The heater 16 is arranged to surround the resin 4 that is introduced through the inlet 14 and flows inside the main body 6. The heater 16 heats and melts the resin 4. A power cable 22 connected to a power source is provided at the base side of the grip portion 8a of the main body 6, and the power cable 22 is connected to the heater 16 inside the main body 6.

[0046] The heater 16 is powered by power supplied from a power cable 22. The heater 16 is, for example, a PTC (Positive Temperature Coefficient) heating element, and has the function of heating an object to a predetermined temperature. The heater 16 is configured to heat the resin 4 to a temperature exceeding its melting point or softening point, and heats the resin 4 to, for example, approximately 165°C.

[0047] At the very tip of the main body 6, there is provided an injection part 18 for molten resin 20 formed by heating rod-shaped resin 4 with heater 16. When the operator pulls trigger 8b with his or her finger, the feeding part 12 pushes the rod-shaped resin 4 into the inside of the main body 6, and the molten resin 20 heated by heater 16 is extruded from the injection part 18.

[0048] A material called a hot melt adhesive is preferably used as the material for the resin 4. Examples of materials that can be used for the resin 4 include polyolefin resins, polyester resins, ethylene vinyl acetate resins, and polyamide resins.

[0049] In the melting step S10, rod-shaped resin 4 is introduced into the injection tool 2, and the resin 4 is heated and melted by the heater 16. Then, in the disposing step S20, the injection tool 2 is moved to above the device 5 on the surface 1a of the workpiece 1, and the trigger 8b is pulled to inject the molten resin 20 from the injection tool 2, and the injected resin 20 is disposed on the device 5. The molten resin 20 spreads from the impact point on the device 5 to the surrounding area, and its temperature decreases.

[0050] Next, a solidification step S30 is performed in which the molten resin 20 is solidified on the surface 1a of the workpiece 1 to form a protective member on the surface 1a. FIG. 3A includes a cross-sectional view schematically showing the protective member 9 formed on the surface 1a of the workpiece 1 after the resin 20 has solidified. The resin 20 is solidified by, for example, allowing it to cool. This allows the protective member 9 to be formed, protecting the device 5 formed on the surface 1a of the workpiece 1.

[0051] In the disposing step S20, the molten resin 20 is not disposed in the area along the planned dividing line 3 on the surface 1a of the workpiece 1, so that a predetermined area on the surface 1a of the workpiece 1 along the planned dividing line 3 can be exposed from the protective member 9. In this case, there is no need to perform a process of precisely exposing the resin 20 to light in part, and there is also no need to apply a developer to the resin 20.

[0052] After the solidification step S30, a processing step S40 is performed to process the area of ​​the workpiece 1 where the protective member 9 is not provided. FIG. 3(A) is a cross-sectional view schematically showing the workpiece 1 held on the chuck table 26 of the processing device 24. The chuck table 26 has a function of suction-holding the workpiece 1 to be processed. Note that tape 7 may be attached to the back surface 1b of the workpiece 1 in advance. Furthermore, the outer periphery of the tape 7 may be attached to a ring frame (not shown) made of a metal material.

[0053] The processing of the workpiece 1 is, for example, cutting processing in which the workpiece 1 is cut with an annular cutting blade, laser processing in which a laser beam is irradiated onto the workpiece 1, plasma etching processing in which an etchant gas converted into plasma is applied to the workpiece 1, etc. However, the processing performed in processing step S40 is not limited to these.

[0054] 3(B) is a cross-sectional view schematically showing cutting of the workpiece 1 as an example of processing step S40. The cutting of the workpiece 1 is performed by a cutting device 24a. The cutting device 24a has a chuck table 26 that holds the workpiece 1 by suction, and a cutting unit 28 that cuts the workpiece 1 held by the chuck table 26.

[0055] The cutting unit 28 has a spindle 30 parallel to the upper surface of the chuck table 26, a rotary drive source (not shown) that rotates the spindle 30, and a cutting blade 32 fixed to the tip of the spindle 30. The cutting blade 32 has an annular grinding wheel portion on its outer periphery that contains countless abrasive grains made of diamond or the like and a binder made of resin, metal, or the like that disperses and fixes the abrasive grains.

[0056] When cutting the workpiece 1, the spindle 30 is rotated to rotate the cutting blade 32, and the cutting unit 28 is lowered so that the lower end of the grinding wheel portion of the cutting blade 32 is lower than the back surface 1b of the workpiece 1. Next, the cutting unit 28 and the chuck table 26 are moved relatively in a direction parallel to the upper surface of the chuck table 26, and the rotating cutting blade 32 cuts into the workpiece 1 along the intended division line 3. This forms a division groove in the workpiece 1.

[0057] After cutting the workpiece 1 along one planned dividing line 3, the workpiece 1 is similarly cut along the other planned dividing lines 3 with the cutting blade 32. When the workpiece 1 has been cut along all the planned dividing lines 3, the workpiece 1 is divided into individual chips.

[0058] At this time, the protective member 9 exposes the workpiece 1 along the planned dividing line 3, so the cutting blade 32 does not cut into the protective member 9. Therefore, clogging of the cutting blade 32 caused by cutting the protective member 9 does not occur, and the processing load on the workpiece 1 does not increase.

[0059] 4(A) is a cross-sectional view schematically showing laser processing of the workpiece 1 as another example of processing step S40. The laser processing of the workpiece 1 is performed by a laser processing device 24b. The laser processing device 24b has a chuck table 26 that suction-holds the workpiece 1, and a laser processing unit 34 that laser-processes the workpiece 1 held by the chuck table 26.

[0060] The laser processing unit 34 has a function of focusing a laser beam of a wavelength that can be absorbed by the workpiece 1 onto the workpiece 1. The laser processing unit 34 includes a laser oscillator that can emit a laser beam of a wavelength of, for example, 355 nm, and an optical system that shapes the laser beam into a predetermined shape and irradiates it at a predetermined position, and is provided with a processing head 36 at the end of the optical system. The laser processing unit 34 has a function of emitting a laser beam 38 from the processing head 36 and focusing the laser beam on the workpiece 1.

[0061] When laser processing the workpiece 1, a laser beam 38 is emitted from the processing head 36 and focused on the workpiece 1 at a predetermined height, while the laser processing unit 34 and the chuck table 26 are moved relatively in a direction parallel to the upper surface of the chuck table 26. Then, the workpiece 1 is laser processed (ablation processed) along the planned division lines 3 to form division grooves in the workpiece 1. When the workpiece 1 is laser processed along all of the planned division lines 3, the workpiece 1 can be divided into individual chips.

[0062] It should be noted that there are cases where it is not possible to form high-quality division grooves of sufficient depth by irradiating the workpiece 1 with the laser beam 38 only once along each planned division line 3. In such cases, the laser beam 38 may be irradiated onto the workpiece 1 multiple times while changing the height of the focal point of the laser beam 38. Then, by repeating the laser processing multiple times, division grooves penetrating the back surface 1b of the workpiece 1 are formed in the workpiece 1.

[0063] Here, the protective member 9 exposes the workpiece 1 along the planned dividing line 3, and therefore the processing position is not covered by the protective member 9. Therefore, the protective member 9 is not pushed up by the strong impact caused by the irradiation of the laser beam 38, and the protective member 9 is not partially peeled off from the workpiece 1 by the laser processing.

[0064] 4(B) is a cross-sectional view schematically showing plasma etching of workpiece 1 as yet another example of processing step S40. Plasma etching of workpiece 1 is performed in plasma etching apparatus 24c. Plasma etching apparatus 24c includes chuck table 26 that suction-holds workpiece 1, and a processing chamber (not shown) that houses chuck table 26.

[0065] For example, a pair of electrodes connected to a high-frequency power source are arranged vertically facing each other inside the processing chamber. The lower electrode is housed inside a chuck table 26 that holds the workpiece 1, and a cooling mechanism for cooling the workpiece 1 is provided on the chuck table 26.

[0066] When performing plasma etching, the inside of the processing chamber is evacuated, the air inside is exhausted, etchant gas 40 is introduced into the processing chamber, and a high-frequency voltage is applied to the pair of electrodes. Then, the etchant gas is converted into plasma near the chuck table 26, and the plasma etchant gas 40 acts on the exposed portion of the workpiece 1, etching the workpiece 1 and forming a dividing groove.

[0067] If the workpiece 1 is significantly thicker than the width of the dividing grooves formed in the workpiece 1, the sidewalls of the areas removed along the dividing lines 3 may be significantly damaged by etching while the workpiece 1 is being etched. Therefore, after the etching of the workpiece 1 has progressed to a certain extent, a protective film may be formed to protect the formed wall surfaces, and then etching may be resumed. Then, the etching of the workpiece 1 and the protection of the wall surfaces may be repeated to further excavate the workpiece 1.

[0068] For example, sulfur hexafluoride (SF6) is used as the etchant gas 40. When a protective film is to be formed on the wall surface of the workpiece 1 exposed by etching, a gas such as C4F8 is applied to the wall surface to form the protective film.

[0069] Here, the protective member 9 exposes the workpiece 1 along the planned dividing lines 3, so the processing position is exposed from the protective member 9. In other words, the protective member 9 plays the role of a resist film. In the method for processing a workpiece according to this embodiment, the protective member 9 that functions as a resist film can be easily and quickly formed on the workpiece 1 without using a photosensitive resin and without performing exposure and development processes.

[0070] When the processing step S40 is performed using either method, for example, a division groove 3a (see Figure 5(A), etc.) is formed in the workpiece 1 along the planned division line 3, and the workpiece 1 is divided into individual chips.

[0071] In the method for processing a workpiece according to this embodiment, after the processing step S40 is performed, a removal step S50 is performed in which the protective member 9 is removed from the workpiece 1. The removal step S50 is explained with reference to Figures 5(A), 5(B), and 5(C). In the removal step S50, for example, the protective member 9 is removed from the workpiece 1 by applying tape 11 from above to the protective member 9 of the workpiece 1 and then lifting the tape 11 from the workpiece 1.

[0072] This will be explained in more detail. In the removal step S50, as shown in Fig. 5(A), the tape 11 is positioned above the workpiece 1. Here, the tape 11 includes an adhesive layer exposed downward and a base layer that supports the adhesive layer. Next, the tape 11 is lowered to contact the protective member 9 disposed on the front surface 1a side of the workpiece 1. Fig. 5(B) is a cross-sectional view that schematically shows the tape 11 in contact with and attached to the protective member 9.

[0073] Thereafter, the tape 11 is pulled upward. Fig. 5(C) is a cross-sectional view schematically showing the state in which the tape 11 has been pulled upward. When the tape 11 is pulled upward, the protective members 9 disposed on the devices 5 are peeled off from the surface 1a of the workpiece 1 all at once, and are removed from the workpiece 1.

[0074] As described above, in the protective member disposing method and workpiece processing method according to this embodiment, the molten resin 20 can be disposed in a predetermined area of ​​the workpiece 1 by using an injection tool 2 capable of injecting the molten resin 20. In this way, the protective member 9 is disposed in a predetermined area on the surface 1a of the workpiece 1. According to this method, the protective member 9 can be disposed in the predetermined area easily and inexpensively.

[0075] In the disposing step S20, the molten resin 20 injected from the injection tool 2 onto the device 5 of the workpiece 1 flows and spreads in a circular shape on the device 5 until it solidifies in the solidifying step S30. However, the device 5 formed on the surface 1a of the workpiece 1 is often rectangular.

[0076] Therefore, to form a protective member 9 that sufficiently covers the entire device 5, the amount of molten resin 20 injected onto each device 5 must be large enough to reach the corners of the device 5. However, in this case, the resin 20 spreads far away from each side of the device 5, resulting in a large amount of resin 20 being used. Also, the area of ​​the workpiece 1 that is not covered by the protective member 9 becomes smaller, and a sufficiently large area of ​​the surface 1a of the workpiece 1 cannot be exposed from the protective member 9.

[0077] Therefore, in the disposing step S20, the molten resin 20 may be spread in a desired direction on the surface 1a of the workpiece 1 to form a protective member 9 that sufficiently covers the entire area of ​​the device 5 but does not cover positions far away from the device 5. FIG. 6(A) is a plan view that schematically shows how the molten resin 20 is spread on the surface 1a of the workpiece 1. In the example shown in FIG. 6(A), the molten resin 20 is stretched using the injection unit 18 of the injection tool 2.

[0078] More specifically, first, molten resin 20 is injected into the center of device 5. Then, while the lower end of injection unit 18 is buried in molten resin 20, injection unit 18 is moved toward one corner of device 5. This causes resin 20 to be stretched toward that corner. Thereafter, injection unit 18 is moved toward another corner of device 5, further stretching molten resin 20. This process is repeated until molten resin 20 is stretched over all four corners. In FIG. 6, trajectory 18a of injection unit 18 is indicated by a dashed line.

[0079] Here, when the injection unit 18 is close to a corner of the device 5, the injection unit 18 may further inject resin 20 as necessary. On the other hand, when the injection unit 18 is close to the center of one of the sides of the device 5, the injection unit 18 does not further inject molten resin 20. This allows the corner of the device 5 to be sufficiently covered with the resin 20, and prevents the resin 20 from spreading to positions far from the device 5. Thereafter, by performing the solidification step S30, a protective member 9 that covers the device 5 without waste can be formed.

[0080] Note that the protective member 9 that sufficiently covers the device 5 without waste may be disposed on the workpiece 1 by another procedure. That is, the area where the protective member 9 is disposed may be controlled by another procedure. FIG. 6(B) is a plan view that schematically shows the protective member 13 disposed on the surface 1a of the workpiece 1 by another procedure. The protective member 13 is formed by disposing the resin 20 on the surface 1a of the workpiece 1 while stretching it into a thread-like shape in the disposing step S20, and then solidifying the resin 20 in the solidifying step S30.

[0081] The resin 20 stretched into threads can be formed, for example, by slowly injecting the resin 20 from the injection tool 2 in a state where the resin has low fluidity. Alternatively, the resin 20 can be formed by gripping two points on the ends of the resin 20 injected from the injection tool 2 and pulling the gripped portions apart. However, the method for forming the resin 20 stretched into threads is not limited to these.

[0082] Then, in the disposing step S20, the formed, elongated thread-like resin 20 is disposed on the surface 1a of the workpiece 1. For example, as shown in FIG. 6(B), the thread-like resin 20 is deformed into a spiral shape to cover the device 5 without any gaps. After that, when the temperature of the resin 20 is reduced by performing the solidifying step S30, a protective member 13 is formed to cover the device 5. Note that the resin 20 may deform to fill gaps before solidifying. FIG. 7(A) is a cross-sectional view schematically showing the workpiece 1 on which the thread-like protective member 13 is disposed.

[0083] According to this method, even when the area of ​​the workpiece 1 where processing is not desired or the area requiring protection is not rectangular, a protective member 13 of a shape suited to the purpose can be easily arranged on the surface 1a of the workpiece 1.

[0084] When the thread-like protective member 13 is disposed on the surface 1a of the workpiece 1, the tape 11 may not be used in the removal step S50 for removing the protective member 13, and the thread-like protective member 13 may be pulled up from one end. Fig. 7(B) is a cross-sectional view schematically showing how the thread-like protective member 13 is pulled up from the end.

[0085] The protective member 13 can be pulled up by, for example, using a jig (not shown) such as tweezers that has a pair of gripping parts and whose tip ends can be changed to pick up the protective member 13 with the jig. Alternatively, the protective member 13 may be pulled up by using a single needle-shaped jig that can pierce the protective member 13 and piercing the protective member 13 with the needle-shaped jig. Furthermore, the removal step S50 using the pulling-up technique may be performed on protective members in forms other than the thread-like protective member 13.

[0086] Here, the state in which the molten resin or protective material is stretched into a thread-like shape refers to a state in which the cross-sectional size of the resin or protective material is uniform throughout and the length is extremely long compared to the cross-sectional diameter. This shape can also be called string-like, rope-like, or long, and there are no particular restrictions on the cross-sectional size or length. The term thread-like does not limit the use of the resin or protective material.

[0087] The above description deals with a case in which the resin 4 is melted, the molten resin 20 is injected from the injection tool 2, stretched into a thread, and disposed on the surface 1a of the workpiece 1, and the resin 20 is cooled and solidified on the surface 1a of the workpiece 1, thereby disposing the protective member 13 on the surface 1a of the workpiece 1. However, the timing of solidifying the molten resin 20 is not limited to this. That is, the molten resin 20 may be stretched into a thread, cooled and solidified first to form the thread-like protective member 13, and then the thread-like protective member 13 may be disposed on the workpiece 1.

[0088] Explaining from another perspective, the protective member disposing method and the workpiece processing method according to this embodiment have been mainly described so far in the case where the solidifying step S30 is performed after the disposing step S20. However, the solidifying step S30 may be performed before the disposing step S20 or may be performed simultaneously with the disposing step S20. Figure 10 is a flowchart illustrating the flow of each step of the workpiece processing method according to this embodiment in which the solidifying step S30 is performed before the disposing step S20.

[0089] In reality, the resin 20 starts to cool when it is injected from the injection tool 2, and it is not apparent at what point in time the resin 20 solidifies to become the protective members 9, 13. At the very least, it can be said that both the disposing step S20 and the solidifying step S30 have been completed when the molten resin 20 is injected from the injection tool 2 and the protective members 9, 13 are disposed on the workpiece 1.

[0090] The filamentous protective member, which can be formed by injecting molten resin 20 from the injection tool 2, stretching the resin 20 into a filamentous shape, and solidifying it, can be disposed on various types of workpieces for various uses. For example, the filamentous protective member can be suitably disposed on a pipe-shaped workpiece 15 having a communicating hole 17 as shown in FIG. 8(A).

[0091] Next, a description will be given of a protective member disposing method according to this embodiment and a method for processing a workpiece when a thread-like protective member is disposed on a pipe-shaped workpiece 15. The flow of each step will be described below with reference to the flowchart shown in FIG.

[0092] First, a melting step S10 is performed in which the resin 4 is melted using the injection tool 2 shown in Fig. 2. Next, a solidification step S30 is performed in which the molten resin 20 is injected from the injection tool 2, the molten resin 20 is stretched into a thread-like shape, and the resin 20 is solidified to form a thread-like protective member 19 (see Fig. 8(B)).

[0093] Here, the thickness of the thread-like protective member 19 is determined by the length of the molten resin 20 before and after it is stretched. More specifically, the rate of change in the cross-sectional area of ​​the resin 20 before and after it is stretched is inversely proportional to the rate of change in the length of the resin 20 before and after it is stretched. For example, if the resin 20 is stretched to twice its original length, the cross-sectional area of ​​the resin 20 will be halved. Therefore, the thickness of the thread-like protective member 19 can be controlled by the length to which the molten resin 20 is stretched.

[0094] Then, in the solidification step S30, the thickness (diameter) of the thread-like protective member 19 is preferably determined with reference to the thickness (diameter) of the communicating hole 17 of the pipe-shaped workpiece 15. For example, the thickness of the thread-like protective member 19 is preferably equal to or smaller than the thickness of the communicating hole 17. However, if the thread-like protective member 19 is too thin, the thread-like protective member 19 will not be able to perform the function described below. Therefore, for example, the thickness of the thread-like protective member 19 is preferably at least half the thickness of the communicating hole 17. However, the thickness of the thread-like protective member 19 is not limited to this.

[0095] Next, an arranging step S20 is performed in which the thread-like protective member 19 is arranged on the workpiece 15. Fig. 8(B) is a perspective view that schematically shows the arranging step S20. For example, in the arranging step S20, the thread-like protective member 19 is arranged on the workpiece 15 by receiving the thread-like protective member 19 in the communication hole 17 of the workpiece 15.

[0096] More specifically, one end of the thread-like protective member 19 is inserted into the communicating hole 17 of the workpiece 15, and the thread-like protective member 19 is pushed into the communicating hole 17. If the thread-like protective member 19 is thicker than the communicating hole 17, it will be difficult to accommodate the thread-like protective member 19 in the communicating hole 17.

[0097] Furthermore, the length of protective member 19 does not need to match the length of workpiece 15. If protective member 19 is longer than workpiece 15, one or both ends of protective member 19 housed in communicating hole 17 will protrude from workpiece 15, making it easier to eventually remove protective member 19 from workpiece 15. In other words, protective member 19 can be removed from workpiece 15 simply by pinching and pulling out the protruding ends of protective member 19.

[0098] Next, a processing step S40 is performed in which the workpiece 15 on which the thread-like protective member 19 is disposed is processed. FIG. 9(A) is a perspective view schematically showing the workpiece 15 to be processed. For example, the workpiece 15 is cut by the cutting blade 32 of the cutting device 24a shown in FIG. 3(B), and a processed groove is formed in the workpiece 15. When the processed groove reaches the opposite end from the end of the workpiece 15, the workpiece 15 is cut.

[0099] For example, if the thread-like protective member 19 is not provided in the through-hole 17 of the pipe-shaped workpiece 15, when the cutting blade 32 is brought into contact with the workpiece 15, the workpiece 15 will be pressed by the cutting blade 32, deformed, and crushed. In this case, the processing position will be shifted, and the workpiece 15 will not be processed precisely.

[0100] In contrast, if the protective member 19 is disposed in the communicating hole 17, when the workpiece 15 is pressed by the cutting blade 32, the protective member 19 exerts a force on the workpiece 15 to maintain its shape against the force that would deform the workpiece 15. Therefore, the workpiece 15 is less likely to deform during processing, and the processing position is less likely to shift. Therefore, precise processing of the workpiece 15 can be achieved.

[0101] It is also possible to fill the communicating holes 17 of the workpiece 15 with powdered resin material instead of the thread-like protective member 19, heat and melt the powdered resin material inside the workpiece 15, and then dispose the protective member inside the communicating holes 17. In this case, however, the workpiece 15 needs to be able to withstand the temperature at which the resin material melts.

[0102] It is also not easy to introduce the powdered resin material into every corner of the communicating holes 17. Furthermore, the protective member formed by solidifying the molten powdered resin inside the communicating holes 17 may adhere to the inside of the communicating holes 17 and be difficult to remove. In contrast, if thread-like protective members 19 are formed and placed in the communicating holes 17 of the workpiece 15, these problems do not occur.

[0103] After the processing of the workpiece 15 is completed, a removing step S50 is performed to remove the thread-like protective member 19 from the workpiece 15. Fig. 9(B) is a perspective view that schematically shows the removing step S50.

[0104] For example, in the removal step S50, the thread-like protective member 19 housed in the communication hole 17 is removed from the workpiece 15 by pushing it out from the workpiece 15. To push out the thread-like protective member 19, for example, a convex jig 42 may be used. The convex jig 42 has a convex portion 44 whose thickness (diameter) is smaller than the thickness (diameter) of the communication hole 17.

[0105] When the convex portion 44 is inserted from one end of the communicating hole 17 while the thread-like protective member 19 is pushed with the convex jig 42, a part of the thread-like protective member 19 comes out from the opposite end of the communicating hole 17, making it possible to pinch and pull out the exposed part of the protective member 19. Alternatively, if the length of the convex portion 44 of the convex jig 42 is longer than the workpiece 15, the tip of the convex portion 44 can be inserted into the communicating hole 17 and pushed through the communicating hole 17, thereby removing the thread-like protective member 19 from the workpiece 15.

[0106] Furthermore, when at least one end of the thread-like protective member 19 is exposed from the communication hole 17 of the workpiece 15, the thread-like protective member 19 can be pulled out from the workpiece 15 without using the convex jig 42. That is, the convex jig 42 does not necessarily have to be used in the removal step S50.

[0107] As described above, in the protective member disposing method and workpiece processing method according to this embodiment, the resin 20 injected from the injection tool 2 is disposed on the workpiece 1 and solidified, thereby disposing the protective members 9, 13 on the workpiece 1. According to this method, the protective members 9, 13 can be disposed on the surface 1a of the workpiece 1 easily and inexpensively without performing a step of removing the protective members 9, 13 from unnecessary positions.

[0108] Furthermore, according to the protective member disposing method and the workpiece processing method of this embodiment, the protective member 19 can be disposed relatively easily in the communicating hole 17 even for a pipe-shaped workpiece 15. Furthermore, the protective member 19 can also be removed relatively easily from the communicating hole 17 of the workpiece 15.

[0109] The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the above-described embodiment describes a case in which the protective member 19 is disposed in the communication hole 17 of the pipe-shaped workpiece 15, and then the workpiece 15 is machined. However, one aspect of the present invention is not limited to this.

[0110] In order to fix the protective member 19 to the workpiece 15, the protective member 19 may be heated and melted before processing the workpiece 15. In this case, the protective member 19 is fixed to the workpiece 15 in the process of cooling and solidifying the molten protective member 19. Therefore, the protective member 19 is less likely to move while the workpiece 15 is being processed.

[0111] Furthermore, even when processing the workpiece 1 by arranging thread-like protective members 13 on the workpiece 1, which is partitioned by a plurality of mutually intersecting planned division lines 3 and has devices 5 formed in each region of the surface 1a, the protective members 13 may be heated and melted. In this case, too, the protective members 13 adhere to the surface 1a of the workpiece 1 as they cool and solidify. Therefore, the regions of the surface 1a that need to be protected can be sufficiently protected by the protective members 13 while the workpiece 1 is being processed.

[0112] In the above embodiment, the case has been described where the operator holds the grip portion 8a of the injection tool 2 having the heater 16 in his / her hand and pulls the trigger 8b with his / her finger to inject the molten resin 20 from the injection tool 2, but one aspect of the present invention is not limited to this. That is, in one aspect of the present invention, the operator does not need to handle the injection tool 2 by hand, and the molten resin 20 may be injected into the workpiece 1 using an injection device equipped with another type of injection tool.

[0113] For example, the injection device includes an injection tool having a heater capable of heating the resin and capable of injecting molten resin, a support table capable of supporting the workpiece 1 on its upper surface, and a movement unit capable of relatively moving the injection tool and the support table in a direction parallel to the upper surface of the support table. The injection device then injects the molten resin from the injection tool into a predetermined position on the workpiece 1 while controlling the relative positions of the injection tool and the support table.

[0114] In addition, the structures, methods, etc. according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0115] 1,15 Workpiece 1a surface 1b back side 3 Planned division line 3a split groove 5 Devices 9, 13, 19 Protective materials 7,11 Tape 17 Communication hole 2 Injection tool 4. Resin 6 Main unit 8a Grip 8b Trigger 10 Support part 12 Feeding section 14 Introduction 16 Heater 18 Injection part 18a locus 20 Molten resin 22 Power cable 24 Processing equipment 24a cutting equipment 24b Laser processing equipment 24c Plasma Etching Equipment 26 Chuck table 28 Cutting unit 30 spindles 32 Cutting blade 34 Laser processing unit 36 Processing head 38 Laser Beam 40 Etchant Gas 42 Convex jig 44 Convex part

Claims

1. 1. A protective member disposing method for a workpiece, the workpiece having devices formed in each region of the surface thereof, partitioned by a plurality of mutually intersecting planned dividing lines, and disposing a protective member on the surface while exposing the workpiece along the planned dividing lines, the method comprising: a melting step of melting the resin using an injection tool having a heater and injecting the resin while heating and melting the resin with the heater; a disposing step of disposing the molten resin injected from the injection tool onto the device on the surface of the workpiece; and a solidification step of solidifying the resin on the surface of the workpiece to thereby dispose the protective member on the surface.

2. 2. The method for providing a protective member according to claim 1, wherein the providing step includes providing the molten resin on the surface of the workpiece while stretching the resin into a thread-like shape.

3. 3. The method for providing a protective member according to claim 1, wherein the resin is a polyolefin resin or a polyester resin.

4. A method for processing a workpiece, the method comprising: exposing a workpiece along the planned dividing lines, the workpiece being partitioned by a plurality of planned dividing lines that intersect with each other and having devices formed in each area of ​​the surface; disposing a protective member on the surface of the workpiece; and processing the workpiece along the planned dividing lines, a melting step of melting the resin using an injection tool having a heater and injecting the resin while heating and melting the resin with the heater; a disposing step of disposing the molten resin injected from the injection tool onto the device on the surface of the workpiece; a solidification step of solidifying the resin on the surface of the workpiece to provide a protective member on the surface; a processing step of processing an area of ​​the workpiece where the protective member is not provided after the solidifying step; a removing step, after the processing step, of attaching tape to the protective member of the workpiece from above and removing the protective member from the workpiece by lifting the tape from the workpiece.

5. 5. The method for processing a workpiece according to claim 4, wherein in the disposing step, the molten resin is disposed on the surface of the workpiece while being stretched into a thread-like shape.

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