Manufacturing method of chip

Abstract

To provide a manufacturing method of a chip capable of suppressing complication of management of chemicals caused by a protective member covering a workpiece.SOLUTION: A manufacturing method of a chip used for manufacturing a plurality of chips by dividing a workpiece, in which a plurality of predetermined dividing lines are set on a surface, along the predetermined dividing lines includes: a protective member forming step of forming a water soluble protective member covering a surface side of the workpiece; a cutting step of cutting the workpiece from the side of the protective member along the predetermined dividing lines using a cutting blade; and a protective member removing step of removing the protective member from the surface side of the workpiece. In the cutting step, the workpiece is cut while making the protective member residual at the surface side of the workpiece by supplying water having a first temperature or lower to the protective member. In the protective member removing step, the protective member is removed from the surface side of the workpiece by supplying water, having a second temperature higher than the first temperature, to the protective member.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for manufacturing chips used when dividing a workpiece to manufacture a plurality of chips.

Background Art

[0002] In electronic devices typified by mobile phones and personal computers, device chips having devices such as electronic circuits are essential components. A device chip is obtained, for example, by partitioning the surface side of a wafer made of a material such as silicon (Si) into a plurality of regions by linear planned division lines, forming devices in each region, and then dividing the wafer along the planned division lines.

[0003] When dividing a plate-shaped workpiece typified by a wafer into a plurality of chips, a cutting device in which a processing tool called a cutting blade is attached to a spindle may be used (see, for example, Patent Document 1). By rotating the cutting blade at high speed and cutting the cutting blade into the planned division line of the workpiece while supplying a liquid such as water, the workpiece is cut along the planned division line and divided into a plurality of chips.

[0004] By the way, when a cutting blade rotated at high speed is cut into a workpiece such as a wafer on which a device including an insulator film with a low dielectric constant called a Low-k film is formed, the Low-k film may be peeled off over a wide range and the device may be damaged. In order to solve this problem, for example, it is conceivable to cover the surface side of the workpiece where the Low-k film is provided with a protective member such as a resin film, and then cut the cutting blade into the workpiece.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The protective member used in the method as described above needs to remain on the surface side of the workpiece until the cutting of the workpiece by the cutting blade is completed so that the surface side of the workpiece is appropriately protected. Therefore, the protective member is made of a material that does not easily dissolve in, for example, water used during processing. However, in this case, when removing the protective member after processing the workpiece, chemicals such as acids, alkalis, and organic solvents are required, which complicates the management of chemicals such as the storage of chemicals and the treatment of waste liquids containing chemicals after use.

[0007] Therefore, an object of the present invention is to provide a method for manufacturing a chip that can suppress the complication of chemical management caused by a protective member that covers a workpiece.

Means for Solving the Problems

[0008] According to one aspect of the present invention, there is provided a method for manufacturing a chip used when manufacturing a plurality of chips by dividing a workpiece having a plurality of division planned lines set on its surface along the division planned lines, the method including: a protective member forming step of forming a water-soluble protective member that covers the surface side of the workpiece; a cutting step of cutting the workpiece along the division planned lines from the protective member side with a cutting blade after the protective member forming step; and a protective member removing step of removing the protective member from the surface side of the workpiece after the cutting step. In the cutting step, the workpiece is cut while leaving the protective member on the surface side of the workpiece by supplying water at a first temperature or lower to the protective member. In the protective member removing step, the protective member is removed from the surface side of the workpiece by supplying water at a second temperature or higher, which is higher than the first temperature, to the protective member.

[0009] Preferably, in the protective member forming step, a member obtained by molding a water-soluble thermoplastic resin into a film shape is heated to be softened or melted and then pressure-bonded to form the protective member adhered to the surface side of the workpiece.

[0010] Also preferably, in the protective member forming step, in a state of being molded into a film with a thickness of 10 μm or more and 80 μm or less, when water at the first temperature is supplied, it dissolves and is removed in 7 seconds or more and 125 seconds or less per 1 μm of thickness, and when water at the second temperature is supplied, it dissolves and is removed in 0.1 second or more and 1.0 second or less per 1 μm of thickness. The protective member is formed using a water-soluble resin having such properties.

[0011] Also preferably, in the protective member forming step, the protective member is formed using polyvinyl alcohol having a saponification degree of 96 mol% or more. Also preferably, the first temperature is 25°C and the second temperature is 50°C.

Advantages of the Invention

[0012] In the method for manufacturing a chip according to one aspect of the present invention, in the protective member forming step, a water-soluble protective member covering the surface side of the workpiece is formed. In the cutting step, water at a first temperature or lower is supplied to the protective member. In the protective member removing step, water at a second temperature or higher, which is higher than the first temperature, is supplied to the protective member.

[0013] Therefore, in the cutting step, the workpiece can be cut while leaving the protective member on the workpiece with water at a first temperature or lower, while in the protective member removing step, the protective member can be removed from the workpiece with water at a second temperature or higher. That is, since there is no need to use chemicals to remove the protective member, the management of chemicals is not complicated due to the protective member.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a perspective view showing the appearance of a workpiece 11 used in the method for manufacturing a chip according to this embodiment. As shown in FIG. 1, the workpiece 11 is, for example, a disk-shaped wafer made of a semiconductor such as silicon (Si), and has a circular surface (first surface) 11a and a circular back surface (second surface) 11b opposite to the surface 11a.

[0016] On the surface 11a side of the workpiece 11, a functional layer (not shown) composed of one or more films is provided. This functional layer is composed of, for example, a metal film that becomes wiring or the like, an insulating film (which may include a Low-k film) that insulates between wirings or the like, a semiconductor film, or the like. Representative examples of the Low-k film used in the functional layer include an inorganic insulating film made of an inorganic material such as SiOF or SiOB, and an organic insulating film made of a polymer such as a polyimide-based or parylene-based polymer.

[0017] The surface 11a side of this workpiece 11 is partitioned into a plurality of small regions by a plurality of linear division planned lines (streets) 13 having a predetermined width, and each small region is provided with a device 15 such as an IC (Integrated Circuit) including a functional layer as a component. A part of the functional layer such as an insulating film is also formed on the division planned line 13.

[0018] In this embodiment, a disk-shaped wafer made of a semiconductor such as silicon is used as the workpiece 11, but the material, shape, structure, size, etc. of the workpiece 11 are not limited. For example, a substrate made of other materials such as semiconductors, ceramics, resins, and metals may be used as the workpiece 11. Similarly, there are no restrictions on the type, quantity, shape, structure, size, arrangement, etc. of the devices 15. The device 15 may not be formed on the workpiece 11.

[0019] In the method for manufacturing a chip according to this embodiment, the workpiece 11 configured as described above is divided by the planned division line 13, whereby a plurality of chips each including the device 15 are manufactured. Specifically, the workpiece 11 is cut along the planned division line 13 using a processing tool called a cutting blade.

[0020] First, in order to protect the surface 11a side of the workpiece 11 from the cutting blade, a water-soluble protective member that covers the surface 11a side is formed (protective member forming step). In this embodiment, the protective member is formed by closely adhering a resin film to the workpiece 11 by a method such as thermocompression bonding. FIG. 2 is a side view schematically showing a state in which the resin film 21 that will later become the protective member is closely adhered to the workpiece 11.

[0021] The resin film 21 can be obtained, for example, by molding a water-soluble thermoplastic resin whose solubility in water varies greatly depending on temperature into a film shape with an arbitrary thickness, preferably a thickness of 10 μm or more and 80 μm or less. Examples of such a thermoplastic resin having such properties include PVA (polyvinyl alcohol) with a high degree of saponification. Note that PVA becomes less soluble in cold water as the degree of saponification increases.

[0022] Here, the degree of saponification of PVA is preferably 97% or more when the degree of polymerization of PVA is 600 or more and less than 1700, and preferably 96% or more when the degree of polymerization of PVA is 1700 or more.

[0023] For example, when water at 25°C is supplied, the resin film 21 with a thickness of 40 μm composed of such PVA dissolves and is removed in 280 seconds or more and 5000 seconds or less. In other words, when water at 25°C is supplied, the water-soluble resin constituting this resin film 21 dissolves and is removed in 7 seconds or more and 125 seconds or less per 1 μm thickness. Therefore, for example, if the time until the cutting of the workpiece 11 is completed is 280 seconds or less, this resin film 21 functions appropriately as a protective member for protecting the surface 11a side of the workpiece 11 by adjusting the temperature of the water used during cutting to 25°C or less.

[0024] Also, for example, when water at 50°C is supplied, the resin film 21 with a thickness of 40 μm composed of such PVA dissolves and is removed in 4 seconds or more and 40 seconds or less. In other words, when water at 50°C is supplied, the water-soluble resin constituting this resin film 21 dissolves and is removed in 0.1 seconds or more and 1.0 seconds or less per 1 μm thickness. Therefore, for example, if the time allowed for cleaning to remove the protective member is 40 seconds or more, this resin film 21 is appropriately removed without using chemicals by supplying water adjusted to 50°C or higher. Thus, PVA satisfying the above-described conditions is suitable as a material for the resin film 21 constituting the protective member.

[0025] Note that the PVA used for the resin film 21 may contain other monomer units as long as the above-described characteristics are not lost.Examples of monomer units that can be included in PVA include α-olefins such as ethylene, propylene, 1-butene, isobutene, 1-hexene, etc., acrylic acid and its salts, and acrylic acid esters such as methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, octadecyl acrylate, etc., methacrylic acid and its salts, and methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, octadecyl methacrylate, etc., acrylamide, N-methylacrylamide, N-ethylacrylamide, N,N-dimethylacrylamide, diacetone acrylamide, acrylamide propanesulfonic acid and its salts, acrylamide propyldimethylamine and its salts, acrylamide derivatives such as N-methylolacrylamide and its derivatives, methacrylamide, N-methylmethacrylamide, N-ethylmethacrylamide, methacrylamide propanesulfonic acid and its salts, methacrylamide propyldimethylamine and its salts, methacrylamide derivatives such as N-methylolmethacrylamide and its derivatives, N-vinylamides such as N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, etc., allyl ethers having a polyalkylene oxide in the side chain, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n-butyl vinyl ether, i-butyl vinyl ether, t-butyl vinyl ether, dodecyl vinyl ether, stearyl vinyl ether, etc., nitriles such as acrylonitrile, methacrylonitrile, etc., vinyl halides such as vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, etc., allyl compounds such as allyl acetate, allyl chloride, etc., maleic acid and its salts or its esters, vinylsilyl compounds such as vinyltrimethoxysilane, isopropenyl acetate, etc.

[0026] In addition, a plasticizer may be added to the water-soluble thermoplastic resin used for the resin film 21. That is, the water-soluble thermoplastic resin used for the resin film 21 may contain a plasticizer in addition to PVA as described above. By adding a plasticizer to the resin film 21, the resin film 21 is more likely to deform following the shape of the surface 11a of the workpiece 11, and the resin film 21 can be more reliably adhered to the workpiece 11.

[0027] As such a plasticizer, those generally used as a plasticizer for PVA can be used without limitation. Specific examples of the plasticizer include polyhydric alcohols such as glycerin, diglycerin, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylolpropane, pentaerythritol, 1,3-butanediol; polyethers such as polyethylene glycol and polypropylene glycol; polyvinylamides such as polyvinylpyrrolidone; amide compounds such as N-methylpyrrolidone and dimethylacetamide; compounds obtained by adding ethylene oxide to polyhydric alcohols such as glycerin, pentaerythritol, and sorbitol, or water. Note that only one of these plasticizers may be added to the resin film 21, or two or more may be added.

[0028] In addition, these plasticizers may be added to the resin film 21 for the purpose of enhancing water solubility in addition to the purpose of enhancing followability to the workpiece 11. In order to enhance the water solubility of the resin film 21, it is preferable to use glycerin, diglycerin, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, trimethylolpropane, polyethylene glycol, polyvinylpyrrolidone, etc. as the plasticizer. In order to suppress a decrease in the water solubility of the resin film 21 due to bleed-out of the plasticizer, it is particularly preferable to use glycerin, diglycerin, trimethylolpropane, polyethylene glycol, polyvinylpyrrolidone, etc. as the plasticizer.

[0029] Note that the time during which the resin film 21 should be maintained without melting and the time allowed until the resin film 21 melts and is removed vary depending on the time required until the cutting of the workpiece 11 is completed, the time allowed for cleaning the workpiece 11, and the like. Therefore, the thickness of the resin film 21 may be arbitrarily changed according to these conditions.

[0030] When the resin film 21 is adhered to the workpiece 11, for example, the protective member forming device 2 shown in FIG. 2 is used. This protective member forming device 2 includes a support table 4 configured to support the workpiece 11 from below. Inside the support table 4, a heater 6 capable of heating the workpiece 11 placed on the upper surface 4a of the support table 4 is arranged.

[0031] Above the support table 4, a support roller (not shown) for supporting the belt-shaped resin film 21 wound in a cylindrical shape and a take-up roller (not shown) for taking up the resin film 21 fed out from the support roller are arranged. Further, at a position downstream of the support roller and upstream of the take-up roller, a pair of guide rollers 8, 10 for guiding the resin film 21 fed out from the support roller above the support table 4 are arranged so as to sandwich the space above the support table 4.

[0032] Also, at a position between the pair of guide rollers 8, 10, a pressing roller 12 capable of applying pressure downward from above to the resin film 21 guided above the support table 4 is arranged. The pressing roller 12 is supported by, for example, a roller moving mechanism (not shown) including a ball screw, and moves in a direction generally parallel (horizontal direction) to the upper surface 4a of the support table 4 and in a direction generally perpendicular (vertical direction) to the upper surface 4a by the force generated by this roller moving mechanism.

[0033] When the resin film 21 is brought into close contact with the workpiece 11 using the protective member forming apparatus 2 configured as described above, first, the workpiece 11 is placed on the support table 4 such that the back surface 11b of the workpiece 11 contacts the upper surface 4a of the support table 4. Thereby, the workpiece 11 is supported by the support table 4 with the surface 11a facing upward.

[0034] When the workpiece 11 is supported by the support table 4, for example, the workpiece 11 is heated by the heat emitted from the heater 6. Also, the resin film 21 fed out from the support roller is guided by the pair of guide rollers 8 and 10 and disposed above the workpiece 11. Thereafter, the roller moving mechanism lowers the pressing roller 12 between the pair of guide rollers 8 and 10.

[0035] Thereby, the pressing roller 12 contacts the resin film 21 disposed above the workpiece 11, and a part of this resin film 21 contacts the surface 11a of the workpiece 11 due to the downward pressure applied from the pressing roller 12. As described above, the workpiece 11 is heated by the heat emitted from the heater 6. Therefore, a part of the resin film 21 that contacts the surface 11a of the workpiece 11 is softened or melted by this heat.

[0036] Then, a part of the softened or melted resin film 21 is pressure-bonded to the surface 11a of the workpiece 11 by the pressure from the pressing roller 12. Thereafter, as shown in FIG. 2, with the height of the pressing roller 12 with respect to the support table 4 maintained, the roller moving mechanism moves the pressing roller 12 in a direction substantially parallel to the upper surface 4a of the support table 4. Thereby, the resin film 21 is thermally pressure-bonded to the entire surface 11a of the workpiece 11, and the resin film 21 adheres closely to the workpiece 11.

[0037] After the resin film 21 is adhered to the workpiece 11 by thermal pressure bonding, the resin film 21 is cut in accordance with the workpiece 11, and a protective member is formed. FIG. 3 is a side view schematically showing a state in which the resin film 21 is cut to form a protective member. Also when cutting the resin film 21, the protective member forming apparatus 2 is continuously used.

[0038] As shown in FIG. 3, above the support table 4, a film cutting unit 14 is arranged in a manner that does not interfere with the pair of guide rollers 8, 10 and the pressing roller 12. The film cutting unit 14 includes a rod-shaped spindle 16 that is long in a direction substantially perpendicular to the upper surface 4a of the support table 4.

[0039] This spindle 16 is supported, for example, by a vertical movement mechanism (not shown) including a ball screw, and moves in a direction substantially perpendicular to the upper surface 4a of the support table 4 by the force generated by this vertical movement mechanism. Also, a rotational drive source such as a motor is connected to the proximal end (upper end) side of the spindle 16, and the spindle 16 rotates around a rotational axis (central axis) that is substantially perpendicular to the upper surface 4a of the support table 4 and passes through the inside of the spindle 16 by the force generated by this rotational drive source.

[0040] At the tip (lower end) side of the spindle 16, the central portion of a support member 18 having a predetermined length in a direction perpendicular to the rotational axis of the spindle 16 is fixed. The support member 18 is configured, for example, in a disk shape having a slightly larger diameter than the workpiece 11. And at the peripheral portion of the support member 18, a blade 20 capable of cutting the resin film 21 is attached downward. The distance from the rotational axis of the spindle 16 to the attachment position of the blade 20 is typically about the radius of the workpiece 11.

[0041] When cutting the resin film 21 in accordance with the workpiece 11, first, the position of the spindle 16 in a direction substantially perpendicular to the upper surface 4a of the support table 4 is adjusted by the vertical movement mechanism so that the tip (lower end) of the blade 20 cuts into the resin film 21. Then, the rotational drive source rotates the spindle 16.

[0042] As a result, the blade 20 moves along the periphery of the workpiece 11, and the resin film 21 is cut according to the size of the workpiece 11. Incidentally, the position of the spindle 16 may be adjusted so that the tip of the blade 20 cuts into the resin film 21 while the spindle 16 is rotating. As described above, a water-soluble protective member 23 (see FIG. 4) that covers the surface 11a side of the workpiece 11 is completed.

[0043] After the protective member 23 is formed, the workpiece 11 is divided into a plurality of chips by cutting the workpiece 11 from the protective member 23 side along each division planned line 13 (cutting step). FIG. 4 is a cross-sectional view schematically showing how the workpiece 11 is cut. In the present embodiment, before the cutting of the workpiece 11 is started, a tape 31 is attached to the back surface 11b side of the workpiece 11. Then, an annular frame (not shown) that surrounds the workpiece 11 is fixed to the peripheral edge of the tape 31. Thereby, the handleability of the workpiece 11 is enhanced.

[0044] When cutting the workpiece 11, for example, the cutting device 32 shown in FIG. 4 is used. This cutting device 32 includes a disk-shaped chuck table 34 that can hold the workpiece 11 supported by the frame via the tape 31. A part of the upper surface 34a of the chuck table 34 functions as a holding surface for holding the workpiece 11 and is typically composed of porous ceramics.

[0045] A part of the upper surface 34a that functions as a holding surface is connected to a suction source such as an ejector via a flow path (not shown) provided inside the chuck table 34 or a valve arranged outside the chuck table 34. Incidentally, four clamps (not shown) for gripping the annular frame are provided around the chuck table 34.

[0046] A rotary drive source such as a motor is connected to the lower part of the chuck table 34. The chuck table 34 rotates around a rotation axis that passes through the center of the upper surface 34a of the chuck table 34 and is substantially perpendicular to the upper surface 34a by the force generated by this rotary drive source. Further, the chuck table 34 is supported by a table movement mechanism (not shown), and moves along a first direction (machining feed direction) that is substantially parallel to the upper surface 34a of the chuck table 34 by the force generated by this table movement mechanism.

[0047] Above the chuck table 34, a cutting unit 36 is arranged. The cutting unit 36 includes a cylindrical spindle housing 38. A part of a bar-shaped spindle 40 that is substantially perpendicular to the first direction and long in a second direction (index feed direction) that is substantially parallel to the upper surface 34a of the chuck table 34 is accommodated in the space inside the spindle housing 38.

[0048] An annular cutting blade 42 having a structure in which abrasive grains such as diamond are dispersed in a binder such as resin is attached to one end side of the spindle 40 exposed from the spindle housing 38. A rotary drive source (not shown) such as a motor is connected to the other end side of the spindle 40, and the spindle 40 rotates around a rotation axis that is substantially parallel to the second direction by the force generated by this rotary drive source.

[0049] A pair of nozzles 44 that can spray water (cutting fluid) 33 toward the workpiece 11 and the cutting blade 42 are arranged so as to sandwich the cutting blade 42 at a position away from the cutting blade 42 along the second direction. The injection port of the nozzle 44 is directed toward the machining point where the cutting blade 42 contacts the workpiece 11, and when the cutting blade 42 is cut into the workpiece 11 or the like, water 33 is sprayed from the injection port of this nozzle 44 toward the machining point.

[0050] When machining the workpiece 11 using the cutting device 32 configured as described above, first, the back surface 11b side of the workpiece 11 is held by the chuck table 34. Specifically, the workpiece 11 is placed on the chuck table 34 such that the tape 31 attached to the workpiece 11 contacts the upper surface 34a of the chuck table 34.

[0051] Next, the valve is opened, and the negative pressure generated by the suction source acts on the tape 31 from the upper surface 34a of the chuck table 34. As a result, the tape 31 is sucked by the chuck table 34, and the workpiece 11 is held by the chuck table 34 via this tape 31. The annular frame fixed to the peripheral edge of the tape 31 is gripped by four clamps.

[0052] Next, the workpiece 11 is cut by the cutting blade 42. Specifically, the rotation drive source adjusts the orientation of the chuck table 34 so that the target division planned line 13 set on the workpiece 11 follows the first direction of the cutting device 32. Also, the table movement mechanism adjusts the position of the chuck table 34 along the first direction and the cutting unit movement mechanism adjusts the position of the cutting unit 36 along the second direction so that the cutting blade 42 is disposed above the extension line of the target division planned line 13.

[0053] Then, the cutting unit movement mechanism adjusts the vertical position of the cutting unit 36 so that the position (height) of the lower end of the cutting blade 42 is slightly lower than the upper surface of the tape 31 attached to the workpiece 11. After that, with the cutting blade 42 rotating, the table movement mechanism moves the chuck table 34 along the first direction. Thereby, the rotating cutting blade 42 cuts into the target division planned line 13 of the workpiece 11, and the workpiece 11 is cut along this division planned line 13.

[0054] After the workpiece 11 is cut by the target division line 13, the same procedure is performed for another division line 13, and the workpiece 11 is cut by this other division line 13. These procedures are repeated until the workpiece 11 is cut by all the division lines 13 and a plurality of chips 17 (see FIG. 5) are obtained.

[0055] During the cutting blade 42 cutting into the workpiece 11, water 33 is supplied from the nozzle 44 to the machining point. Here, when the time required to finish cutting one workpiece 11 is 280 seconds, the protective member 23 needs to remain on the surface 11a side of the workpiece 11 without completely dissolving in the water 33 for at least 280 seconds. Therefore, in this embodiment, water 33 at a temperature below the first temperature is supplied to the machining point including the protective member 23 so as to satisfy this condition.

[0056] For example, when the protective member 23 with a thickness of 40 μm is formed of PVA satisfying the above-described conditions, the first temperature which is the upper limit of the temperature of the water 33 is set to 25°C. Thereby, until the cutting of the workpiece 11 is completed, the protective member 23 does not completely dissolve and remains on the surface 11a of the workpiece 11, and the surface 11a side of the workpiece 11 can be protected.

[0057] There is no particular limitation on the lower limit of the temperature of the water 33 supplied when cutting the workpiece 11. The temperature of the water 33 may be arbitrarily changed within the range of 5°C or more and 25°C or less, for example, according to the time required to finish cutting one workpiece 11. Also, the flow rate of the water 33 supplied from the nozzle 44 is, for example, 0.5 L / min to 3.0 L / min, and typically about 1.5 L / min. However, the flow rate of the water 33 supplied from the nozzle 44 can be arbitrarily changed within the range where the workpiece 11 is properly cut.

[0058] After the workpiece 11 is divided into a plurality of chips 17, the protective member pieces 25 generated by cutting the protective member 23 together with the workpiece 11 are removed from the surface (first surface) 17a side of each chip 17 corresponding to the surface 11a of the workpiece 11 (protective member removal step). FIG. 5 is a cross-sectional view schematically showing the state where the protective member 23 (protective member piece 25) is removed from the workpiece 11 (chip 17).

[0059] When removing the protective member pieces 25 from each chip 17, for example, the cleaning device 52 shown in FIG. 5 is used. This cleaning device 52 includes a disk-shaped spinner table 54 that can hold a plurality of chips 17 (workpiece 11) supported by a frame via a tape 31. On the upper surface 54a of the spinner table 54, for example, suction ports are provided, and a part of the upper surface 54a of the spinner table 54 functions as a holding surface for holding the plurality of chips 17.

[0060] The suction ports provided on the upper surface 54a of the spinner table 54 are connected to a suction source such as an ejector via a flow path (not shown) provided inside the spinner table 54 or a valve or the like arranged outside the spinner table 54. A rotational drive source such as a motor is connected to the lower part of the spinner table 54. The spinner table 54 rotates around a rotation axis that passes through the center of the upper surface 54a of the spinner table 54 and is substantially perpendicular to the upper surface 54a by the force generated by this rotational drive source.

[0061] Around this spinner table 54, four clamps (not shown) for gripping an annular frame are provided. Further, above the spinner table 54, a nozzle 56 capable of injecting cleaning water (cleaning liquid) 35 downward from the tip is arranged. A rotational drive source such as a motor is connected to the proximal end side of the nozzle 56, and the tip of the nozzle 56 swings so as to draw a substantially circular arc-shaped locus parallel to the upper surface 54a of the spinner table 54 by the force generated by this rotational drive source.

[0062] When removing the protective member pieces 25 from each chip 17 using the cleaning device 52, first, the back surface (second surface) 17b side of the plurality of chips 17 is held by the spinner table 54. Specifically, the plurality of chips 17 are placed on the spinner table 54 such that the tape 31 attached to the plurality of chips 17 contacts the upper surface 54a of the spinner table 54.

[0063] Next, the valve is opened, and the negative pressure generated by the suction source acts on the tape 31 from the upper surface 54a of the spinner table 54. As a result, the tape 31 is sucked by the spinner table 54, and the workpiece 11 is held by the spinner table 54 via this tape 31. Then, the rotation drive source rotates the spinner table 54. Note that the annular frame fixed to the peripheral edge of the tape 31 is fixed by four clamps when the spinner table 54 rotates.

[0064] Thereafter, water 35 is sprayed from the tip of the nozzle 56 toward the plurality of lower chips 17. Note that the tip of this nozzle 56 sprays water 35 toward the plurality of chips 17 while swinging in a plane substantially parallel to the upper surface 54a of the spinner table 54. As a result, the protective member pieces 25 are dissolved in the water 35, and the protective member 23 is removed from the surface 11a side of the workpiece 11.

[0065] Here, when the time allowed to remove the protective member 23 (all the protective member pieces 25) covering one workpiece 11 is, for example, 40 seconds, the protective member 23 needs to be dissolved in the water 35 and removed from the surface 11a side of the workpiece 11 in a maximum of 40 seconds. Therefore, in the present embodiment, water 35 at a temperature of 2nd temperature or higher is supplied to the protective member 23 (protective member pieces 25) so as to satisfy this condition.

[0066] For example, when the protective member 23 with a thickness of 40 μm is formed of PVA satisfying the above-described conditions, the second temperature, which is the lower limit of the temperature of the water 35, is set to 50°C. Thereby, the protective member 23 is appropriately removed from the surface 11a side of the workpiece 11 in a short time. Also, it is not necessary to use chemicals to remove the protective member 23.

[0067] Note that there is no particular limitation on the upper limit of the temperature of the water 35 supplied when removing the protective member 23 (all the protective member pieces 25) covering the workpiece 11. The temperature of the water 35 may be arbitrarily changed within the range of 50°C or higher and 80°C or lower, for example, according to the time allowed for removing the protective member 23 (all the protective member pieces 25). Also, the flow rate of the water 35 supplied from the nozzle 56 is, for example, 0.1 L / min to 1.0 L / min, and typically about 0.2 L / min. However, the flow rate of the water 35 injected from the nozzle 56 can be arbitrarily changed within the range in which the protective member 23 is appropriately removed. Also, this water 35 may be injected from the nozzle 56 in a state mixed with a gas such as air.

[0068] As described above, in the method for manufacturing a chip according to the present embodiment, first, a water-soluble protective member 23 covering the surface 11a side of the workpiece 11 is formed (protective member forming step), and then, when the workpiece 11 is cut, water 33 at a temperature equal to or lower than the first temperature is supplied to the protective member 23 (cutting step), and thereafter, when the protective member 23 is removed, water 35 at a second temperature equal to or higher than the first temperature is supplied to the protective member 23 (protective member removing step).

[0069] Therefore, when the workpiece 11 is cut, the workpiece 11 can be cut while leaving the protective member 23 on the workpiece 11 with the water 33 at a temperature equal to or lower than the first temperature, while when the protective member 23 is removed, the protective member 23 can be removed from the workpiece 11 with the water 35 at a temperature equal to or higher than the second temperature. That is, since it is not necessary to use chemicals to remove the protective member 23, the management of chemicals is not complicated due to the protective member 23.

[0070] Note that the present invention is not limited to the description of the above-described embodiments and can be implemented with various modifications. For example, in the above-described embodiment, the workpiece 11 is divided into a plurality of chips 17 by being cut by the cutting blade 42. However, after the surface 11a side of the workpiece 11 is cut by the cutting blade 42, the workpiece 11 may be divided into a plurality of chips 17 by another method.

[0071] Specifically, for example, when the cutting blade 42 is inserted into the workpiece 11 at a depth where it is not cut, a groove that opens to the surface 11a side is formed in the workpiece 11 (cutting step). Thereafter, by grinding the entire back surface 11b side of the workpiece 11, the workpiece 11 is divided into a plurality of chips 17 (grinding step). Note that when the workpiece 11 is not cut by the cutting blade 42 in this way, the tape 31 and the frame do not necessarily have to be used.

[0072] Also, in the above-described embodiment, the protective member 23 that is in close contact with the surface 11a side of the workpiece 11 is formed by heating, softening, or melting the resin film 21 obtained by molding a water-soluble thermoplastic resin into a film shape and then performing pressure bonding. However, the protective member 23 may be formed by another method such as spin coating.

[0073] In addition, the structures, methods, etc. according to the above-described embodiments and modified examples can be implemented with modifications as long as they do not depart from the scope of the object of the present invention.

Explanation of Reference Numerals

[0074] 11: Workpiece 11a: Surface (first surface) 11b: Back surface (second surface) 13: Division planned line (street) 15: Device 17: Chip 17a: Surface (first surface) 17b: Back surface (second surface) 21: Resin film 23: Protective member 25: Protective member piece 31: Tape 33: Water (cutting fluid) 35: Water (cleaning fluid) 2: Protective member forming device 4: Support table 4a: Upper surface 6: Heater 8: Guide roller 10: Guide roller 12: Pressing roller 14: Film cutting unit 16: Spindle 18: Support member 20: Blade 32: Cutting device 34: Chuck table 34a: Upper surface 36: Cutting unit 38: Spindle housing 40: Spindle 42: Cutting blade 44: Nozzle 52: Cleaning device 54: Spinner table 54a: Upper surface 56: Nozzle

Claims

1. A method for manufacturing chips, which is used when manufacturing a plurality of chips by dividing a workpiece having a plurality of planned division lines set on its surface along the planned division lines, comprising: a protective member forming step of forming a water-soluble protective member covering the surface side of the workpiece; a cutting step of cutting the workpiece along the planned division lines from the protective member side with a cutting blade after the protective member forming step; a protective member removing step of removing the protective member from the surface side of the workpiece after the cutting step, wherein in the cutting step, the workpiece is cut while leaving the protective member on the surface side of the workpiece by supplying water at a first temperature or lower to the protective member, and in the protective member removing step, the protective member is removed from the surface side of the workpiece by supplying water at a second temperature or higher, which is higher than the first temperature, to the protective member.

2. The method for manufacturing chips according to claim 1, wherein in the protective member forming step, the protective member that adheres to the surface side of the workpiece is formed by heating, softening or melting, and then pressure-bonding a member obtained by molding a water-soluble thermoplastic resin into a film shape.

3. The method for manufacturing chips according to claim 1 or 2, wherein in the protective member forming step, the protective member is formed using a water-soluble resin having a property that when water at the first temperature is supplied, it dissolves and is removed in 7 seconds or more and 125 seconds or less per 1 μm of thickness, and when water at the second temperature is supplied, it dissolves and is removed in 0.1 seconds or more and 1.0 second or less per 1 μm of thickness, in a state of being formed into a film having a thickness of 10 μm or more and 80 μm or less.

4. The method for manufacturing chips according to claim 1 or 2, wherein in the protective member forming step, the protective member is formed using polyvinyl alcohol having a saponification degree of 96 mol% or more.

5. The method for manufacturing chips according to claim 1 or 2, wherein the first temperature is 25°C and the second temperature is 50°C.

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