Method for manufacturing chips, method for increasing chip spacing, and processing apparatus.

Abstract

This invention provides a new chip manufacturing method, a method for increasing chip spacing, and a processing apparatus that can solve various problems caused by sheet sagging. [Solution] The chip manufacturing method comprises expanding a sheet on which a workpiece with a division starting point formed thereon is fixed, dividing the workpiece into multiple chips; forming protrusions on a part of the expanded sheet that protrude from the surface formed by the other parts after the workpiece has been divided into multiple chips; and welding together parts of the sheet that are in contact with each other at the protrusions by heating the protrusions.

Description

[Technical Field]

[0001] The present invention relates to a method of manufacturing chips by dividing a workpiece, a method for expanding the spacing between chips manufactured by division, and a processing apparatus for performing these processes. [Background Art]

[0002] In electronic devices represented by mobile phones and personal computers, a chip provided with devices such as electronic circuits (device chip) is an essential component. A device chip is obtained by, for example, dividing a wafer made of a material such as silicon or sapphire into a plurality of regions along planned dividing lines (streets), forming devices in each of the regions, and then dividing the wafer along the planned dividing lines.

[0003] When dividing a plate-shaped workpiece such as a wafer into a plurality of chips, for example, a method is used in which a laser beam having a wavelength that transmits through the workpiece is focused on a planned dividing line to modify that portion. Since the portion modified by the laser beam is more brittle than other portions, when an external force is applied to the workpiece, the workpiece is divided into a plurality of chips along the planned dividing line.

[0004] When a workpiece is divided by such a method, it is general that a sheet having a property of stretching when a force is applied is fixed to the workpiece. For example, when a sheet attached to one side of a plate-shaped workpiece is expanded along the surface direction, a force is applied to the workpiece via this sheet, and the workpiece is divided. Further, when the sheet is further expanded, the gap between adjacent chips is widened, which facilitates operations such as chip pickup.

[0005] An annular frame is fixed to the outer edge of the sheet for convenience of conveyance and the like. That is, the workpiece is handled in the form of a frame unit in which the workpiece is attached to the central portion of the circular sheet and the frame is attached to the outer edge portion.

[0006] The sheet, which forms part of the frame unit, is expanded by pressing an expander against it, for example, perpendicular to the surface, while its outer edge is fixed to the frame.

[0007] In this case, when the seat is extended, the frame does not extend along with the seat, so the extended seat may sag inside the annular frame.

[0008] When the sheet is loose, it may shake during transport, causing adjacent chips to collide and become damaged. Furthermore, the expanded portion of the sheet may contract over time, narrowing the gaps between adjacent chips. Narrow spacing between chips makes it difficult to pick up individual chips.

[0009] Therefore, as described in Patent Document 1, for example, a technique has been proposed in which heat is applied to the portion of the expanded sheet that lies between the workpiece and the frame, thereby actively shrinking this portion. In the technique described in Patent Document 1, by shrinking the area of ​​the sheet (dicing tape) that lies around the workpiece, the sheet becomes taut, preventing collisions between adjacent chips. In addition, the sheet becomes less likely to shrink at the position corresponding to the gap between adjacent chips, thus maintaining the gap between the chips. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2005-142365 [Overview of the project] [Problems that the invention aims to solve]

[0011] However, the ease with which a sheet shrinks due to heat varies depending on the sheet's material, dimensions, etc. When a sheet that does not shrink easily due to heat is used, the problems caused by sheet sagging cannot be solved by the method described above. Furthermore, even when a sheet that shrinks easily due to heat is used, the method described above was not sufficient to solve the problems when the chip size was small or when it was desired to increase the spacing between adjacent chips.

[0012] The object of the present invention is to provide a novel chip manufacturing method, a method for increasing chip spacing, and a processing apparatus that can solve various problems caused by sheet sagging. [Means for solving the problem]

[0013] According to one aspect of the present invention, a method for manufacturing chips is provided, comprising: expanding a sheet on which a workpiece having a division starting point formed is fixed, thereby dividing the workpiece into a plurality of chips; forming protrusions on a portion of the expanded sheet after the workpiece has been divided into a plurality of chips, with respect to the surface formed by the other portions; and welding the plurality of portions of the sheet that are in contact with each other by heating the protrusions.

[0014] Preferably, when welding the sheet, the protrusion is heated from one side of the surface facing the outside of the protrusion, while the other side of the surface facing the outside of the protrusion is supported by a support member.

[0015] Preferably, the sheet is welded with a cover material placed between the heat source used for welding and the workpiece, and the cover material includes a support member that supports the protruding portion.

[0016] Preferably, the method for manufacturing the chip further comprises, after dividing the workpiece and before forming the protrusion, holding the side of the sheet opposite to the side to which the workpiece is fixed by the holding surface of a workpiece holding unit having a member having a holding surface for holding the workpiece, wherein the cover material is placed on the workpiece before forming the protrusion, and the formation of the protrusion is carried out with the sheet sandwiched between the holding surface of the workpiece holding unit and the cover material.

[0017] Preferably, in forming the protrusion, a portion of the sheet is sandwiched between the holding surface of the workpiece holding unit and the cover material, and the area of ​​the sheet surrounding the area sandwiched between the holding surface of the workpiece holding unit and the cover material is further expanded.

[0018] Preferably, when welding the sheet, the protrusion is heated by supplying hot air from the side opposite the support member, with the protrusion in between, toward the protrusion.

[0019] Preferably, the protrusion is formed by the sagging of the relaxed sheet.

[0020] According to another aspect of the present invention, a method for increasing the spacing between chips is provided, comprising: expanding a sheet on which a plurality of chips are fixed to increase the spacing between the plurality of chips; forming protrusions on a portion of the expanded sheet that protrude from the surface formed by the other portions after the workpiece has been divided into a plurality of chips; and welding the plurality of portions of the sheet that are in contact with each other by heating the protrusions.

[0021] According to still another aspect of the present invention, there is provided a processing apparatus comprising: a sheet holding unit that holds a sheet to which a workpiece is fixed; a sheet expanding unit that expands the sheet held by the sheet holding unit; and a welding unit that heats a protruding portion formed as a portion protruding relative to other portions in a part of the sheet expanded by the sheet expanding unit, and welds a plurality of portions of the sheet that are in contact with each other to form the protruding portion. [[Effects of the Invention]]

[0022] According to the chip manufacturing method, chip interval expanding method, and processing apparatus according to each aspect of the present invention, after a workpiece is divided to manufacture chips by expanding a sheet to which the workpiece is fixed, and the interval between chips is expanded, a protruding portion formed in a part of the sheet can be welded. This suppresses slack occurring in the sheet, and suppresses occurrence of situations such as contact between chips.

[0023] As described above, according to the chip manufacturing method, chip interval expanding method, and processing apparatus according to each aspect of the present invention, there are provided a new chip manufacturing method, a new chip interval expanding method, and a new processing apparatus that can solve various problems caused by slack of the sheet. [[Brief Description of the Drawings]]

[0024] [Figure 1] FIG. 1 is an exploded perspective view schematically showing an example of the configuration of a workpiece unit. [Figure 2] FIG. 2 is an exploded perspective view showing an example of the configuration of a main part of the processing apparatus. [Figure 3] FIG. 3 is a perspective view showing an example of a state where a workpiece unit is held by the processing apparatus. [Figure 4] FIG. 4 is a flowchart showing an example of procedures related to a chip manufacturing method and a chip interval expanding method. [Figure 5] FIG. 5 is a side cross-sectional view schematically showing a state of each part in one step of the procedure shown in FIG. 4, and shows an example of arrangement of each part in a sheet arranging step. [Figure 6] Figure 6 is a schematic side cross-sectional view showing the state of each part in another step of the procedure shown in Figure 4, illustrating an example of the arrangement of each part in the sheet expansion step. [Figure 7] Figure 7 is a schematic side cross-sectional view showing the state of each part in yet another step of the procedure shown in Figure 4, illustrating an example of the arrangement of each part in the workpiece holding step. [Figure 8] Figure 8 is a schematic side cross-sectional view showing the state of each part in yet another step of the procedure shown in Figure 4, illustrating an example of the arrangement of each part in the protection step. [Figure 9] Figure 9 is a schematic side cross-sectional view showing the state of each part in yet another step of the procedure shown in Figure 4, illustrating an example of the arrangement of each part in the protruding part formation step. [Figure 10] Figure 10 is a schematic side cross-sectional view showing the state of each part in yet another step of the procedure shown in Figure 4, illustrating an example of the state of each part in the welding step. [Figure 11] Figure 11 is a schematic side cross-sectional view showing the state of each part in yet another step of the procedure shown in Figure 4, illustrating another example of the state of each part in the welding step. [Figure 12] Figure 12 is a schematic side cross-sectional view illustrating another example of the state of each part during the welding step. [Figure 13] Figure 13 is a schematic side cross-sectional view illustrating yet another example of the state of each part during the welding step. [Figure 14] Figure 14 is a schematic side cross-sectional view illustrating yet another example of the state of each part during the welding step. [Figure 15] Figure 15 is a schematic side cross-sectional view illustrating yet another example of the state of each part during the welding step. [Modes for carrying out the invention]

[0025] A method and apparatus according to one aspect (embodiment) of the present invention will be described with reference to the attached drawings.

[0026] First, the workpiece unit to be handled in this embodiment will be described. Figure 1 is a schematic exploded perspective view showing an example of the configuration of the workpiece unit. The workpiece unit 2 is formed with the workpiece 4, frame 6, and sheet 8 as its constituent elements.

[0027] The workpiece 4 is a disc-shaped wafer made of a semiconductor material such as single-crystal silicon. Multiple division lines (streets) arranged in a grid pattern are set on the workpiece 4, thereby dividing the plate-shaped workpiece 4 into multiple rectangular regions. Devices such as ICs (Integrated Circuits), LSIs (Large Scale Integrations), LEDs (Light Emitting Diodes), and MEMS (Micro Electro Mechanical Systems) devices are formed on the surface of each region divided by the streets.

[0028] The workpiece 4 undergoes a laser modification process along the street, and this area functions as the starting point for division when the workpiece 4 is split. Note that the method for creating the split section in the workpiece 4 is not limited to laser processing. For example, it is also conceivable that grooves be formed by cutting the surface of the workpiece 4 with a blade, so that these grooves become the split sections.

[0029] There are no restrictions on the type, material, shape, structure, size, etc., of the workpiece 4. For example, the workpiece 4 may be a substrate (wafer) made of semiconductors other than silicon (GaAs, InP, GaN, SiC, etc.), sapphire, glass, ceramics, resin, metal, etc. There are also no restrictions on the type, number, shape, structure, size, arrangement, etc., of the devices formed on the workpiece 4.

[0030] The workpiece 4 is handled in a frame unit state, held in an annular frame 6 as shown in Figure 1, for convenience of handling such as transport and holding. The frame 6 is a plate-shaped part made of metal such as SUS (stainless steel), and an opening is provided in the center of the frame 6 that penetrates the frame 6 in the thickness direction. The diameter of this opening is set to be larger than the diameter of the workpiece 4.

[0031] The workpiece 4 is supported by the frame 6 via a sheet 8. The sheet 8 is composed of, for example, a circular film-like base material with a diameter larger than the central opening of the frame 6, and an adhesive layer provided on the base material. The base material is formed from an elastic resin such as polyolefin, polyvinyl chloride, or polyethylene terephthalate. The adhesive layer is made from an epoxy, acrylic, or rubber-based adhesive, and this material is applied to at least one side of the base material to form the adhesive layer.

[0032] With the workpiece 4 positioned inside the opening of the frame 6 and surrounded by the frame 6, the central part of the sheet 8 is attached to the workpiece 4, and the outer periphery of the sheet 8 is attached to the frame 6, thereby supporting the workpiece 4. In this state, the adhesive surface of the sheet 8 that is not attached to either the frame 6 or the workpiece 4 is exposed in an annular shape between the outer periphery of the sheet 8 fixed to the frame 6 and the central region of the sheet 8 fixed to the workpiece 4.

[0033] Figure 2 is an exploded perspective view showing an example of the configuration of the main parts of the processing apparatus 10 that handles the workpiece unit 2 as described above. Figure 3 is a perspective view showing an example of the state in which the workpiece unit 2 is held in the processing apparatus 10.

[0034] The processing apparatus 10 of this embodiment includes a sheet holding unit 12, a workpiece holding unit 14, a sheet expansion unit 16, and a welding unit 18.

[0035] The sheet holding unit 12 is a mechanism that holds the sheet 8 on which the workpiece 4 is fixed, as shown in Figure 1 of the workpiece unit 2. In the example shown in Figures 2 and 3, the sheet holding unit 12 is equipped with two annular members (clamping bodies 12a) whose inner circumference diameter (dimension in the direction intersecting the thickness direction) is larger than the outer circumference diameter of the workpiece 4. The two annular members forming the clamping bodies 12a are plate-shaped members formed from materials such as metal and resin.

[0036] As shown in Figure 3, the two clamping bodies 12a surround the workpiece 4 and hold the area of ​​the sheet 8 outside the outer circumference of the workpiece 4 by clamping it from both sides. When holding the sheet 8, the two clamping bodies 12a may hold the sheet 8 by clamping it from both sides, or the sheet 8 may be held by the two clamping bodies 12a holding the frame 6 to which the sheet 8 is fixed from both sides.

[0037] When the two clamping bodies 12a hold the sheet 8 by clamping it, the inner diameter of each clamping body 12a is set to be smaller than the outer diameter of the sheet 8. When the two clamping bodies 12a hold the frame 6 to which the sheet 8 is fixed by clamping it, the inner diameter of each clamping body 12a is set to be smaller than the outer diameter of the frame 6.

[0038] When the sheet 8 or frame 6 is held between the two clamping bodies 12a, force is applied from both sides to the two clamping bodies 12a holding the sheet 8 or frame 6, for example, by a clip (not shown) that uses elastic force to hold an object. Other mechanisms, such as a magnetic mechanism, may be used to apply force to the clamping bodies 12a.

[0039] Although not shown in the diagram, the sheet holding unit 12 may also include, for example, one clamping body, and the sheet 8 may be held by sandwiching the sheet 8 between the clamping body and the frame 6. In that case, the diameter of the inner circumference of the clamping body is set to be smaller than the diameter of the outer circumference of the sheet 8.

[0040] Although the clamping body 12a is shown here as an annular member, the shape of the clamping body 12a is not limited to an annular shape, and other shapes are acceptable as long as the sheet 8 can be held securely. For example, the clamping body 12a may be C-shaped, or it may be configured in which multiple members are arranged circumferentially to surround the workpiece 4.

[0041] However, in order for the sheet 8 to be uniformly expanded in the procedure described later (sheet expansion step S20; see Figure 4), an annular shape that surrounds the workpiece 4 in a closed line is preferable for the shape of the clamping body 12a. This is because a uniform force can be easily applied to the sheet 8 along the surface direction.

[0042] The workpiece holding unit 14 is a mechanism for holding the workpiece 4, and is, for example, a chuck table that holds the workpiece 4 by negative pressure. The workpiece holding unit 14, which is a chuck table, comprises a frame made of, for example, ceramics, metal, etc., and a suction body attached to the frame. The frame is generally cylindrical in shape, and a disc-shaped recess is formed on its end face.

[0043] The adsorbent is a disc-shaped member formed from a material such as porous ceramics or metal. When the adsorbent is formed from a material such as metal, it is provided with holes that penetrate the adsorbent in the thickness direction.

[0044] The disc-shaped adsorbent is attached to the frame by fitting it into a recess provided in the frame. A gas flow channel is formed inside the frame, and a suction source (not shown), such as a vacuum pump, is connected to this channel. When negative pressure is supplied to the channel by the operation of the suction source, an object such as a workpiece 4 in contact with the surface of the adsorbent is adsorbed to the surface through the holes in the adsorbent.

[0045] Thus, the end face of the workpiece holding unit 14 on which the suction body is provided forms a holding surface 14a that suctions the workpiece 4, etc. The holding surface 14a of the workpiece holding unit 14 can, for example, suction the workpiece 4 by sandwiching the sheet 8 between them, or it can suction the workpiece 4 by directly contacting it.

[0046] In the example shown here, the workpiece holding unit 14 is attached to the processing apparatus 10 with its holding surface 14a facing downwards, and the workpiece 4 is attracted to the upper holding surface 14a by the aforementioned suction force.

[0047] The orientation of the holding surface 14a, the suction mechanism, and the shape and material of each part of the workpiece holding unit 14 are not limited to the examples shown herein. The workpiece holding unit 14 may have any form or mechanism as long as it is able to suitably hold the intended object (workpiece 4). For example, the holding surface 14a may be oriented upward or sideways, and the workpiece holding unit 14 may hold the workpiece 4 by a mechanism other than suction by negative pressure.

[0048] Alternatively, the workpiece holding unit 14 may not have a mechanism for holding the object by suction force or the like, but may be an article that holds the workpiece 4 by sandwiching it between itself and the cover material 20, which will be described later.

[0049] The shape of the member having a holding surface in the workpiece holding unit 14 may be, for example, a plate shape such as a disc or polygon, or it may be cylindrical, prismatic, truncated cylindrical, truncated prismatic, etc. The workpiece holding unit 14 may have any shape as long as it has a holding surface capable of holding the workpiece 4.

[0050] The sheet expansion unit 16 is a mechanism for expanding the sheet 8 held by the sheet holding unit 12, and in this embodiment, it is formed as a ring-shaped article as shown in Figure 2.

[0051] In the procedure described later (sheet expansion step S20), the sheet expansion unit 16 contacts the sheet 8 held by the sheet holding unit 12 and applies force to the sheet 8 to expand it. For this reason, at least the portion of the sheet expansion unit 16 that contacts the sheet 8 in the sheet expansion step S20 has an inner diameter that is larger than the outer diameter of the workpiece 4, and an outer diameter that is smaller than the outer diameter of the sheet 8.

[0052] The sheet extension unit 16 of this embodiment comprises a circular, annular main body 16a and a plurality of rollers 16b mounted on the main body 16a as an axis. The plurality of rollers 16b are arranged along the circumferential direction of the main body 16a and rotate around the main body 16a as an axis of rotation.

[0053] The sheet holding unit 12, the workpiece holding unit 14, and the sheet expansion unit 16 are mounted on the processing device 10 in a positional relationship such that the central axes of these units are roughly aligned with each other, and they are also designed to move relative to each other as needed by a moving mechanism (not shown).

[0054] The sheet holding unit 12 is normally located below the workpiece holding unit 14, which is attached to the processing apparatus 10 with its holding surface 14a facing downwards (at a position separated from the workpiece holding unit 14 on the opposite side of the workpiece holding unit 14 in the axial direction of the workpiece holding unit 14, but can move up and down relative to the workpiece holding unit 14 as needed (moving along the axial direction of the workpiece holding unit 14 near the height of the holding surface 14a).

[0055] In this case, the sheet holding unit 12 may move relative to the workpiece holding unit 14, or the workpiece holding unit 14 may move relative to the sheet holding unit 12, or both may move. When the sheet holding unit 12 is above the holding surface 14a, the sheet holding unit 12 is positioned so as to surround the workpiece holding unit 14.

[0056] Similarly, the sheet expansion unit 16 is normally located below the workpiece holding unit 14, but can move up and down relative to the workpiece holding unit 14 as needed. Also, the sheet expansion unit 16 is normally located above the position where the sheet 8 is held relative to the sheet holding unit 12 (between the height where the sheet 8 is held in the sheet holding unit 12 (between the two clamping bodies 12a) and the height of the holding surface 14a of the workpiece holding unit 14), but can move up and down relative to both the sheet holding unit 12 and the workpiece holding unit 14 as needed.

[0057] In this case, the sheet expansion unit 16 may move relative to the sheet holding unit 12 and the workpiece holding unit 14, or the sheet holding unit 12 and the workpiece holding unit 14 may move relative to the sheet expansion unit 16, or all of them may move relative to each other. When the sheet expansion unit 16 is above the holding surface 14a, the sheet expansion unit 16 is positioned so as to surround the workpiece holding unit 14.

[0058] The welding unit 18 is a mechanism for heating a portion of the sheet 8 (protruding portion 8a) in the procedure described later (welding step S60; see Figure 4). In the example shown in Figures 2 and 3, the welding unit 18 is a heater that blows out heated air as hot air, and is attached to the processing apparatus 10 below the workpiece holding unit 14, with the outlet for the hot air directed towards the workpiece holding unit 14 above.

[0059] In this embodiment, a plurality of welding units 18 (four in this case) are arranged circumferentially with respect to the axis of the workpiece holding unit 14. These welding units 18 rotate circumferentially around the central axis of the sheet holding unit 12 and the workpiece holding unit 14 by a rotation mechanism (not shown).

[0060] Regarding the welding unit 18, any mechanism or form of device may be used, as long as it can suitably heat a portion of the sheet 8 (the protruding portion 8a). The number of welding units 18 installed may be one or two or more. Also, the arrangement of the welding units 18 does not have to be symmetrical with respect to the axis of the workpiece holding unit 14.

[0061] In the processing apparatus 10, a cover material 20 as shown in Figure 2 is used. The cover material 20 is an article used to cover and protect the surface of the workpiece 4 in the procedure described later (protection step S40 to welding step S60; see Figure 4), and is supported in an appropriate position relative to the workpiece 4 by a support mechanism (not shown).

[0062] In this embodiment, the cover material 20 is formed comprising a disc-shaped main surface portion 20a and a support member 20b provided on the edge of the main surface portion 20a.

[0063] The outer diameter of the main surface portion 20a is set to be larger than the outer diameter of the workpiece 4 and smaller than the inner diameter of the sheet holding unit 12.

[0064] The support member 20b is a ring-shaped portion that protrudes from the outer circumference of the disc-shaped main surface portion 20a in the thickness direction of the main surface portion 20a (the axial direction of the disc-shaped main surface portion 20a). The outer surface 20c of the support member 20b has a tapered shape in which the diameter decreases as it moves away from the main surface portion 20a in the axial direction, and approaches the axis in the radial direction.

[0065] The angle that the outer circumferential surface 20c of the support member 20b makes with respect to the central axis of the main surface portion 20a (a virtual axis that penetrates the center of the disc-shaped main surface portion 20a perpendicularly to the surface formed by the main surface portion 20a) is approximately -3°, for example, when the point where the outer circumferential surface 20c and the main surface portion 20a intersect is the center in a plane containing the central axis of the main surface portion 20a, and the direction parallel to the central axis of the main surface portion 20a (the direction perpendicular to the surface formed by the main surface portion 20a) is defined as 0°, the direction moving outward along the radial direction of the main surface portion 20a from the center is defined as 90°, and the direction moving inward is defined as -90°.

[0066] The shape of the cover material 20 is not limited to the example shown herein and can be changed in various ways depending on the shape of the workpiece 4 and other conditions. For example, the shape of the main surface portion 20a may be dome-shaped or polygonal. The shape of the support member 20b may also be changed as appropriate depending on the shape of the main surface portion 20a and other conditions.

[0067] In the procedure described later (welding step S60), a part of the sheet 8 (protrusion 8a) comes into contact with the outer circumferential surface 20c of the support member 20b, and the protrusion 8a is heated in this state. In order for the heating to be carried out efficiently, it is preferable that the support member 20b, including the outer circumferential surface 20c, be made of a material with high thermal conductivity, such as metal.

[0068] Furthermore, after heating, it is convenient if the outer surface 20c is made of a material that is easily peeled off from the sheet 8, so that the protruding portion 8a of the sheet 8 in contact with the outer surface 20c can be easily peeled off. Alternatively, the outer surface 20c may have irregularities formed on it so that the protruding portion 8a can be easily peeled off.

[0069] For the sake of explanation, the workpiece unit 2 is not shown in Figure 2, and the sheet expansion unit 16 and cover material 20 are not shown in Figure 3.

[0070] Next, a procedure relating to a chip manufacturing method and a chip spacing method using the processing apparatus 10 of this embodiment will be described. Figure 4 is a flowchart showing an example of a procedure relating to a chip manufacturing method and a chip spacing method. Figures 5 to 11 are schematic side cross-sectional views showing the state of each part in each step of the procedure shown in Figure 4.

[0071] The procedure shown in Figure 4 comprises a sheet placement step S10, a sheet expansion step S20, a workpiece holding step S30, a protection step S40, a protrusion formation step S50, and a welding step S60.

[0072] First, with the sheet 8 held by the sheet holding unit 12, the sheet 8 and the sheet expansion unit 16 are positioned relative to each other in the manner shown in Figure 5 (sheet placement step S10). Figure 5 shows an example of the arrangement of each part in the sheet placement step S10.

[0073] In the example shown in Figure 5, the sheet holding unit 12 is equipped with two clamping bodies 12a, and the outer periphery of the sheet 8 to which the frame 6 is fixed is clamped between these two clamping bodies 12a, thereby holding the sheet 8 in the sheet holding unit 12.

[0074] The sheet holding unit 12 may, for example, use two clamping bodies 12a to hold the sheet 8, which is not fixed to the frame 6. In this case, when the sheet 8 is held by the sheet holding unit 12, for example, the frame 6 is peeled off from the sheet 8 that constitutes the workpiece unit 2, and the sheet 8 is reattached to the clamping bodies 12a and held in place.

[0075] Alternatively, the diameter of the outer circumference of each clamping body 12a may be set to be smaller than the diameter of the inner circumference of the frame 6. In this case, the portion of the sheet 8 that is not fixed to the frame 6, but is inside the frame 6, is held in place by the two clamping bodies 12a.

[0076] Alternatively, the sheet holding unit 12 may include one clamping body, and the sheet 8 may be held by sandwiching the sheet 8 between the clamping body and the frame 6. In this case as well, for example, the frame 6 is peeled off from the sheet 8 constituting the workpiece unit 2, and the sheet 8 is reattached to the single clamping body and held in place.

[0077] One side of the sheet 8 held by the sheet holding unit 12 is provided with an adhesive layer, to which the workpiece 4 is fixed by attachment. The sheet expansion unit 16 is positioned on the side opposite to the side to which the workpiece 4 is attached and contacts the sheet 8.

[0078] In the state shown in Figure 5, the sheet 8 is held by the sheet holding unit 12 with the workpiece 4 facing downwards, and the sheet expansion unit 16 is in contact with the sheet 8 from above. In this state, the workpiece 4 is located inward in a plan view relative to the annular sheet expansion unit 16.

[0079] Next, as shown in Figure 6, the sheet expansion unit 16 moves downward relative to the sheet holding unit 12 (sheet expansion step S20). Figure 6 shows an example of the arrangement of each part in the sheet expansion step S20.

[0080] In the state shown in Figure 5, the sheet expansion unit 16 is in contact with the sheet 8 on the side opposite to the workpiece 4. From this state, in the sheet expansion step S20, as shown in Figure 6, the sheet expansion unit 16 moves downward toward the workpiece 4. In this way, the sheet expansion unit 16, which is in contact with the sheet 8, moves toward the sheet holding unit 12 that holds the sheet 8, and as the distance between them increases, the sheet 8 held by the sheet holding unit 12 is pushed by the sheet expansion unit 16, and the sheet 8 held by the sheet holding unit 12 expands.

[0081] In addition, at this time, the seat extension unit 16 may move downward relative to the seat holding unit 12, or the seat holding unit 12 may move upward relative to the seat extension unit 16.

[0082] A workpiece 4, which is a wafer, is fixed to the sheet 8, with division points formed along the streets. As the sheet 8 expands, the workpiece 4, while remaining fixed to the sheet 8, is divided into multiple chips 4a along the streets (for the sake of explanation, the chips 4a formed by the division of the workpiece 4 will also be treated as a form of the workpiece 4 below). As the sheet 8 expands further, the spacing between the multiple chips 4a fixed to the sheet 8 increases.

[0083] At this time, the sheet 8 is in contact with the rollers 16b of the sheet expansion unit 16. Each roller 16b rotates around the annular main body 16a as an axis, and when the sheet 8 is expanded, it rotates in a direction that is roughly aligned with the expansion direction of the sheet 8, which expands radially. As a result, the sheet 8, while in contact with the sheet expansion unit 16, is allowed to move relative to the sheet expansion unit 16 due to the rotation of the rollers 16b, and expands smoothly.

[0084] After the workpiece (wafer) 4 is divided by the expansion of the sheet 8 and the spacing between each chip 4a is increased, the workpiece 4 is held by the workpiece holding unit 14 as shown in Figure 7 (workpiece holding step S30). Figure 7 shows an example of the arrangement of each part in the workpiece holding step S30.

[0085] In the workpiece holding step S30, the side of the sheet 8 opposite to the side on which the workpiece 4 is fixed is held by the holding surface 14a of the workpiece holding unit 14. As described above, the holding surface 14a of the workpiece holding unit 14 is designed to hold the article in contact with the holding surface 14a by negative pressure. The workpiece holding unit 14 contacts the area of ​​the sheet 8 on which the workpiece 4 is fixed with its holding surface 14a, and by supplying negative pressure to the sheet 8, it holds the workpiece 4 on the holding surface 14a, sandwiching the sheet 8 between them.

[0086] In this case, when the workpiece 4 is held in the workpiece holding unit 14 by suction force, it is preferable that the workpiece holding step S30 be performed after the sheet expansion step S20 and before the protrusion formation step S50.

[0087] If the workpiece 4 is adsorbed to the holding surface 14a of the workpiece holding unit 14 before the sheet expansion step S20, the adsorption force may hinder the expansion of the sheet 8. Furthermore, when the protrusion formation step S50 is performed, it is preferable that the workpiece 4 is held and restrained by the workpiece holding unit 14 in order for the protrusion 8a to be formed appropriately.

[0088] Next, as shown in Figure 8, the cover material 20 is placed on the workpiece 4 (chip 4a) (protection step S40). Figure 8 shows an example of the arrangement of each part in protection step S40.

[0089] A workpiece 4 is fixed to one side of the sheet 8, and the holding surface 14a of the workpiece holding unit 14 is in contact with the opposite side, holding the workpiece 4. The workpiece 4 is covered by the cover material 20 in such a manner that the main surface portion 20a is positioned below the workpiece 4 (opposite to the holding surface 14a of the workpiece holding unit 14 that holds the workpiece 4), and the support member 20b surrounds the outer circumference of the workpiece 4. In the example shown in Figure 8, one side (the upper side) of the main surface portion 20a is in contact with the workpiece 4, but depending on the thickness of the workpiece 4 and the dimensions of the support member 20b, the workpiece 4 may be covered by the cover material 20 even when the main surface portion 20a is separated from the workpiece 4.

[0090] In this state, the tip of the support member 20b extending upward from the outer circumference of the main surface portion 20a is in contact with the portion of the sheet 8 located around the workpiece 4. That is, in this portion, the sheet 8 is sandwiched between the support member 20b of the cover material 20 and the holding surface 14a of the workpiece holding unit 14.

[0091] The order of the workpiece holding step S30 and the protection step S40 is not important. The protection step S40 may be performed before the protrusion forming step S50 or before the welding step S60, and may also be performed before the workpiece holding step S30.

[0092] Furthermore, it is conceivable that, for example, the workpiece holding unit 14 itself does not have a mechanism for adsorbing the object, and instead holds the object by sandwiching it between itself and the cover material 20. In that case, the workpiece holding step S30, which holds the workpiece 4, and the protection step S40, which installs the cover material 20 on the workpiece 4, are performed as the same process.

[0093] In this way, the workpiece 4 is divided into chips 4a, and once the workpiece 4 (chips 4a) is held between the holding surface 14a of the workpiece holding unit 14 and the main surface portion 20a of the cover material 20, the sheet holding unit 12 moves downward relative to the workpiece holding unit 14, the sheet expansion unit 16 and the cover material 20, bringing the sheet holding unit 12 and the sheet expansion unit 16 closer together.

[0094] As a result, a portion of the sheet 8 that protrudes from the surface formed by the other parts (protrusion 8a) is formed (protrusion formation step S50). Figure 9 shows an example of the arrangement of each part in the protrusion formation step S50.

[0095] In the sheet expansion step S20, the distance between the sheet expansion unit 16 in contact with the sheet 8 and the sheet holding unit 12 that holds the sheet 8 is increased, thereby expanding the sheet 8 located inside the sheet holding unit 12, and the total area of ​​the sheet 8 inside the sheet holding unit 12 becomes larger than the area of ​​the virtual surface located inside the inner circumference of the sheet holding unit 12. Furthermore, in the workpiece holding step S30 and the protection step S40, the workpiece 4 is held on the holding surface 14a of the workpiece holding unit 14, and the sheet 8 located around the workpiece 4 is sandwiched between the holding surface 14a and the support member 20b of the cover material 20.

[0096] In this state, when the sheet holding unit 12 and the sheet expansion unit 16 move closer to each other, the sheet 8 located between them slackens, and this slack becomes a protrusion 8a. In the example shown in Figure 9, the slackened sheet 8 hangs down due to its own weight, forming a protrusion 8a with a downwardly convex U-shaped cross-section that surrounds the outside of the area where the workpiece 4 is located, extending circumferentially.

[0097] In this case, instead of the sheet holding unit 12 moving, for example, the workpiece holding unit 14, the sheet expansion unit 16, and the cover material 20 may move upward.

[0098] Alternatively, for example, the protrusion 8a may be formed by the workpiece holding unit 14 moving upward relative to the sheet holding unit 12 (in a direction in which the workpiece 4 held between the workpiece holding unit 14 and the cover material 20 approaches the sheet holding unit 12) while the sheet expansion unit 16 remains in contact with the sheet 8. In this case, the sheet 8 will not slacken, and the protrusion 8a will be formed while tension is maintained.

[0099] In addition, the sheet expansion unit 16 may rise slowly relative to the sheet holding unit 12 in accordance with the relative rise of the workpiece holding unit 14 and the cover material 20 relative to the sheet holding unit 12. If the relative rising speed of the sheet expansion unit 16 relative to the sheet holding unit 12 is about half the relative rising speed of the workpiece holding unit 14 and the cover material 20 relative to the sheet holding unit 12, the sheet 8 will not expand excessively, and the protrusion 8a will be formed while maintaining the tension of the sheet 8.

[0100] Incidentally, in the procedure shown in Figure 4, the workpiece holding step S30 and the protection step S40 are performed before the protrusion formation step S50, and the protrusion formation step S50 is performed with the sheet 8 sandwiched between the holding surface 14a of the workpiece holding unit 14 and the support member 20b of the cover material 20.

[0101] When the protrusion formation step S50 is performed in this state, the portion of the sheet 8 sandwiched between the holding surface 14a and the support member 20b is constrained to that position. Therefore, even if the mechanisms such as the sheet holding unit 12, the sheet expansion unit 16, the workpiece holding unit 14, and the cover material 20 operate relative to each other, the area of ​​the sheet 8 inside the support member 20b is less likely to move. Thus, there is an advantage in that the spacing between the multiple chips 4a fixed in that area is easily maintained.

[0102] Furthermore, in the protruding portion forming step S50, from the state in which the sheet 8 is sandwiched between the holding surface 14a and the support member 20b as shown in Figure 8, the workpiece holding unit 14 and the cover material 20 may be moved further downward relative to the sheet holding unit 12.

[0103] When such an operation is performed, the distance between the area of ​​the sheet 8 held by the sheet holding unit 12 (outer edge) and the area held by the holding surface 14a of the workpiece holding unit 14 (central part) is further increased, and the area of ​​the sheet 8 between these two areas (the area of ​​the sheet 8 surrounding the area sandwiched between the holding surface 14a of the workpiece holding unit 14 and the cover material 20; this area will be conveniently referred to as the intermediate area) is further expanded.

[0104] As a result, the dimensions of the slack (protrusion 8a; see Figures 9 and 10) formed in the protrusion formation step S50 become larger, which facilitates the welding of the protrusion 8a in the subsequent welding step S60.

[0105] When expanding the intermediate region of the sheet 8, pressing the workpiece holding unit 14 and the cover material 20 against each other, thereby sandwiching and holding the sheet 8 between the holding surface 14a and the support member 20b, makes it easier to expand the intermediate region. Similarly, turning on the negative pressure supply in the workpiece holding unit 14 and using suction on the holding surface 14a to hold the sheet 8 also makes it easier to expand the intermediate region of the sheet 8. Both sandwiching the sheet 8 between the holding surface 14a and the support member 20b, and suction on the sheet 8 to the holding surface 14a, may be performed.

[0106] Alternatively, for example, the sheet 8 may be sandwiched between the holding surface 14a and the support member 20b, and with the sheet 8 being attracted to the holding surface 14a by negative pressure, the sheet expansion unit 16 may be lowered relative to the workpiece holding unit 14 and the sheet holding unit 12 to expand the intermediate region of the sheet 8.

[0107] When expanding the intermediate region, heating the intermediate region to raise its temperature softens the material of the sheet 8, making it easier to expand. The intermediate region can be heated, for example, by blowing hot air from the welding unit 18 (see Figure 10). The intermediate region may also be heated by a mechanism (not shown) provided separately from the welding unit 18.

[0108] Furthermore, the formation of the protrusion can be carried out in various ways other than those described above. For example, although not shown in the illustration, it is possible to support the sheet 8 with another support member to prevent it from sagging and to form a protrusion that is convex upwards. Alternatively, it is theoretically possible to form a protrusion that is convex upwards by sending an airflow upwards from the welding unit 18 to the sheet 8.

[0109] Furthermore, although the procedure from the sheet placement step S10 to the protrusion formation step S50 has been described here in a manner in which the workpiece 4 is held on the underside of the sheet 8, the procedure may also be performed in a manner in which the workpiece 4 is held on the upper side of the sheet 8. In that case, for example, the sheet expansion unit 16 and the workpiece holding unit 14 are located on the underside of the sheet 8 opposite to the workpiece 4, and the cover material 20 is located on the upper side of the sheet 8, on the same side as the workpiece 4.

[0110] Next, the welding step S60 will be described. Once a protrusion 8a is formed on a part of the sheet 8 by the above procedure, the protrusion 8a is heated by the welding unit 18, and the parts of the sheet forming the protrusion 8a are welded together (welding step S60). Figures 10 and 11 show examples of the state of each part in welding step S60, respectively.

[0111] As shown in Figure 9, the protruding portion 8a, which is part of the sheet 8, is formed to have a U-shaped cross-section, with the inner surfaces of the U-shape facing each other. In this state, the protruding portion 8a is relaxed and hangs down, and one of the outer surfaces of the U-shape is in contact with the outer circumferential surface 20c of the support member 20b, which is provided as part of the cover material 20.

[0112] In welding step S60, as shown in Figure 10, one of the outer surfaces of the U-shaped projection 8a (the surface opposite to the surface in contact with the outer circumferential surface 20c of the support member 20b) is heated by hot air blown from the welding unit 18 below. During this time, the other outer surface of the projection 8a (the surface in contact with the outer circumferential surface 20c of the support member 20b) is supported by the outer circumferential surface 20c of the support member 20b.

[0113] Thus, the protruding portion 8a, which has a U-shaped cross-section, is heated while being pressed against the outer circumferential surface 20c of the support member 20b by the pressure of the hot air, as shown in Figure 11. That is, with the protruding portion 8a aligned with the outer circumferential surface 20c of the support member 20b, hot air is supplied toward the protruding portion 8a from the side opposite the support member 20b, with the protruding portion 8a in between.

[0114] In this state, parts of the sheet 8 are in contact with each other at the protrusions 8a, and multiple parts of the sheet 8 that make up these protrusions 8a (for example, one part on the left and another part on the right of the part of the sheet 8 that has a U-shaped cross-section at the protrusion 8a in the figure) are welded together by the heat supplied from the hot air. As a result, the parts of the sheet 8 that make up the protrusions 8a are heated in close contact with each other, enabling more reliable welding.

[0115] Furthermore, if the material forming the outer circumferential surface 20c of the support member 20b is made of a material with high thermal conductivity, such as metal, the heat supplied from the hot air is quickly conducted through the support member 20b, and the welding of the protruding portion 8a is performed efficiently.

[0116] Furthermore, during welding, as shown in Figures 10 and 11, if hot air is supplied at an angle that intersects with the outer circumferential surface 20c of the support member 20b, the force of the hot air supplied in this direction presses the protrusion 8a against the outer circumferential surface 20c, enabling more efficient welding of the protrusion 8a.

[0117] During welding, as the welding unit 18 rotates relative to the sheet holding unit 12, the position from which hot air is supplied from the welding unit 18 moves along the circumferential direction. As a result, the protrusion 8a formed on the outside of the portion of the sheet 8 that holds the workpiece 4 is welded around its entire circumference. In the relative rotation between the welding unit 18 and the sheet holding unit 12, the welding unit 18 may rotate, the sheet holding unit 12 (sheet holding unit 12 and workpiece holding unit 14, cover material 20) may rotate, or both may rotate.

[0118] The welding step S60 is performed with the cover material 20 placed between the heat source (welding unit 18) used for welding and the workpiece 4 (tip 4a). This protects the workpiece 4 from the heat of the hot air and foreign matter such as sheet 8 debris that may be contained in the hot air.

[0119] After the protrusion 8a of the sheet 8 is welded in place, the cover material 20 is removed from the position covering the workpiece 4. At this time, the protrusion 8a is peeled off from the outer circumferential surface 20c of the support member 20b. If the outer circumferential surface 20c of the support member 20b is made of a material that allows the sheet 8 material to be easily peeled off, the process of separating the protrusion 8a from the support member 20b can be easily performed.

[0120] Here, we will explain the angle formed by the support member 20b. Figure 12 is a schematic side cross-sectional view showing another example of the state of each part in welding step S60.

[0121] As described above, in the examples shown in Figures 2, 3 and 5 to 11, the outer circumferential surface 20c of the support member 20b has a tapered shape in which the diameter decreases as it moves away from the main surface 20a along the direction of its central axis, and approaches the central axis in the radial direction. The angle that the outer circumferential surface 20c of the support member 20b makes with respect to the central axis of the main surface 20a (hereinafter referred to as "the angle made by the outer circumferential surface 20c of the support member 20b" or simply "the angle of the outer circumferential surface 20c") is approximately -3°, for example, when the point where the outer circumferential surface 20c and the main surface 20a intersect is the center in a plane containing the central axis of the disc-shaped main surface 20a, and the direction parallel to the central axis of the main surface 20a and moving upward (towards the sheet 8) is defined as 0°, the direction outward along the radial direction of the main surface 20a from the center is defined as 90°, and the direction inward is defined as -90°.

[0122] In contrast, in the example shown in Figure 12, the outer circumferential surface 20c of the support member 20b has a diameter that increases as it moves away from the main surface portion 20a in the axial direction, and has a shape that moves away from the central axis in the radial direction. The angle formed by the outer circumferential surface 20c of the support member 20b is set to approximately 40°.

[0123] The inventors of the present invention conducted experiments to verify the ease of welding cover material 20 in the shapes shown in Figures 10 and 11, and cover material 20 in the shape shown in Figure 12. As the welding unit 18, a heater that blows hot air upwards was used.

[0124] In the experiment, welding was performed on the sheet holding unit 12 while varying the rotation speed of the welding unit 18, and the state of the protruding portion 8a after welding at each rotation speed was compared and verified. Five different rotation speeds for the welding unit 18 were set: 1° / sec, 2° / sec, 3° / sec, 4° / sec, and 5° / sec.

[0125] As a result, when the cover material 20 in the form shown in Figures 10 and 11 (a cover material 20 in which the angle formed by the outer peripheral surface 20c of the support member 20b is approximately -3°) was used, the protrusion 8a was generally well welded regardless of the rotation speed of the welding unit 18. In particular, when the rotation speed was 1 to 3° / second, the entire circumference of the protrusion 8a was evenly welded. When the rotation speed was 4° / second and 5° / second, some welding defects were observed in parts of the protrusion 8a, but the sagging of the sheet 8 was resolved to some extent.

[0126] On the other hand, when the cover material 20 in the form shown in Figure 12 (a cover material 20 in which the angle formed by the outer peripheral surface 20c of the support member 20b is approximately 40°) was used, welding defects were observed around almost the entire circumference of the protrusion 8a when the rotation speed of the welding unit 18 was 3 to 5° / second. When the rotation speed was 2° / second, welding defects were observed in some parts of the protrusion 8a, but the sagging of the sheet 8 was resolved to some extent. When the rotation speed was 1° / second, the entire circumference of the protrusion 8a was evenly welded.

[0127] Thus, regardless of whether the cover material 20 in Figures 10 and 11, which has a small angle of the outer peripheral surface 20c, or the cover material 20 in Figure 12, which has a large angle of the outer peripheral surface 20c, is used, if the rotation speed of the welding unit 18 is sufficiently slow, the amount of heat per unit time per length in the circumferential direction of the protrusion 8a will be large, and good welding of the protrusion 8a can be achieved. However, if the rotation speed of the welding unit 18 is slow, welding will take longer, which may affect production efficiency.

[0128] In other words, from the standpoint of welding efficiency, it can be said that the smaller the angle of the outer surface 20c, within the range of -90° to 90°, the more advantageous it is. This is because, when a part of the sheet 8 hangs down to form a protrusion 8a, the smaller the angle of the outer surface 20c, the easier it is for the protrusion 8a to come into contact with the outer surface 20c, and therefore, the easier it is for it to be pressed against the outer surface 20c by hot air.

[0129] On the other hand, from the viewpoint of compactness of each part constituting the processing apparatus 10, a larger angle of the outer peripheral surface 20c is advantageous. In the procedure described above, the support member 20b needs to surround the workpiece 4, so the diameter of the tip of the support member 20b must not be less than the diameter of the workpiece 4. Therefore, if the angle of the outer peripheral surface 20c is small, the diameter of the base end of the support member 20b (i.e., the diameter of the outer peripheral surface of the main surface portion 20a of the cover material 20) will be larger, and furthermore, other equipment will also be set to be larger to match the dimensions of the cover material 20 as needed.

[0130] Based on the above, the angle of the outer surface 20c is preferably as small as possible within the range of -90° to 90°, as long as welding is performed successfully. As shown in Figures 10 and 11, when a method is adopted in which the protrusion 8a is pressed against the support member 20b and heated by hot air, the angle formed by the outer surface 20c of the support member 20b is preferably, for example, about -15° to -2°, and more preferably about -5° to -2°.

[0131] In this description, the welding unit 18 used in welding step S60 is described as a device equipped with a heater that blows hot air upwards in the processing apparatus 10. However, the mechanism and form of the welding unit are not limited to the example described here. Various mechanisms and forms of devices can be used as the welding unit, as long as the welding of the protruding portion 8a is performed satisfactorily.

[0132] For example, the welding unit may be a device that contacts the protrusion 8a and heats the protrusion 8a, or it may be a device that irradiates the protrusion 8a with light such as infrared rays and heats the protrusion 8a.

[0133] Figures 13 to 15 show modified examples of the welding unit, and are schematic side cross-sectional views illustrating yet another example of the state of each part in welding step S60.

[0134] In the example shown in Figure 13, a hot-air welding unit 18 similar to the welding unit 18 described in Figures 2, 3, 10, and 11 is used, but the angles of each welding unit 18 are different, and the hot air is blown out in a generally vertical direction.

[0135] In the examples shown in Figures 2, 3, 10, and 11, the hot air was supplied from the welding unit 18 at an oblique angle (an angle in which it was blown inward with respect to the radial direction) in order to effectively press the protrusion 8a against the outer circumferential surface 20c of the support member 20b with the hot air. However, if the volume of supplied hot air is sufficient, even if the angle at which the hot air is blown out is approximately vertical, as in the example shown in Figure 13, the protrusion 8a can be sufficiently pressed against the outer circumferential surface 20c of the support member 20b, and good welding can be achieved.

[0136] In the example shown in Figure 14, the welding unit 18 is equipped with a heater that heats by contacting the protrusion 8a. The welding unit 18 in the example in Figure 14 is, for example, an electric heater that heats the protrusion 8a while pressing it against the outer circumferential surface 20c of the support member 20b.

[0137] In the example shown in Figure 15, a support member 12b for supporting the protruding portion 8a of the sheet 8 is provided at a different location from the cover material 20 (on the sheet holding unit 12). This support member 12b is provided on the inner circumferential surface of one of the two clamping bodies 12a, which are elements of the sheet holding unit 12 (the side on which the protruding portion 8a of the sheet 8 held by the sheet holding unit 12 is formed; the lower side in Figure 15), and forms a mortar-shaped slope whose diameter decreases as it moves away from the part that holds the sheet 8 in the axial direction.

[0138] After the sheet 8 is expanded, the drooping projection 8a contacts the inclined surface of the support member 12b. In the examples shown in Figures 9 to 11, the radially inner portion of the projection 8a contacts the support member 20b provided on the cover material 20, but in the example shown in Figure 15, the radially outer portion contacts the support member 12b provided on the sheet holding unit 12.

[0139] Accordingly, the welding unit 18 is configured to blow hot air from an inward position in the radial direction toward the protrusion 8a toward the outward direction in the radial direction. During welding, hot air is blown toward the protrusion 8a from the inside toward the outside in the radial direction, and the protrusion 8a is heated while being pressed against the support member 12b located toward the outside in the radial direction.

[0140] When the support member 12b is provided in this manner, the angle formed by the inclined surface of the support member 12b is preferably about 15° to 2°, more preferably about 5° to 2°, and typically about 3°, for example, when the direction toward upward (towards the sheet 8) along the axial direction of the annular support member 12b is defined as 0°, the direction toward outward radially from the center of the support member 12b is defined as 90°, and the direction toward inward is defined as -90°.

[0141] In the example shown in Figure 15, the support member 12b is positioned radially outward with respect to the protrusion 8a formed in the area surrounding the workpiece 4 of the sheet 8, and welding is performed by pressing the protrusion 8a against the support member 12b.

[0142] When the protrusion 8a is welded in this manner, the welded protrusion 8a is located radially outward, that is, in a region far from the workpiece 4 fixed radially to the inside of the protrusion 8a. When the protrusion 8a is formed in such a position, it is advantageous in that the protrusion 8a is less likely to interfere with any operation performed on the workpiece 4 after welding, such as picking up the tip 4a.

[0143] Furthermore, various mechanisms and forms of devices can be envisioned for the welding unit and support members, and various configurations can also be envisioned for the welding step using the welding unit and support members.

[0144] For example, when using a hot air welding unit, it is possible to support the protruding part and perform welding by adjusting the direction and volume of the hot air without providing a support member. In this case, for example, if a protruding part has a U-shaped cross-section and hangs down, hot air is supplied from both sides, so that the inner surfaces of the protruding part are in contact with each other as they are sandwiched between the hot air, and welding is performed by the heat of the hot air.

[0145] Alternatively, a method could be considered in which a contact-type welding unit is brought into contact with the protruding part, sandwiching it from both sides, and welding is performed. In this case as well, welding can be performed without using a support member.

[0146] Alternatively, the welding step may be performed with the workpiece 4 held on the upper side of the sheet 8. In this case, for example, the sheet expansion unit 16 and the workpiece holding unit 14 are located on the lower side of the sheet 8 opposite to the workpiece 4, and the cover material 20 is located on the upper side of the sheet 8, on the same side as the workpiece 4.

[0147] In this state, for example, when wind is blown upward onto the sheet 8 from a blower unit located below the sheet holding unit 12, a protruding portion 8a with an upward convex shape is formed on the sheet 8. Alternatively, when the sheet 8 is supported by a support unit located below the sheet holding unit 12 to prevent it from sagging, a protruding portion 8a with an upward convex shape is formed on the sheet 8.

[0148] The resulting upwardly convex protrusion 8a is then welded by blowing hot air from a welding unit 18 located above the sheet holding unit 12. Alternatively, welding is performed by a contact-type welding unit 18 coming into contact with the protrusion 8a.

[0149] As described above, according to the apparatus 10 and the method for manufacturing chips using the same, and the method for expanding the chip spacing according to the embodiment, the workpiece 4 is divided by the expansion of the sheet 8 to produce chips 4a, and after the spacing between the chips 4a is further expanded, the protrusions 8a formed on a part of the sheet 8 are welded.

[0150] If no special measures are taken to address the loosening of the expanded sheet 8 after its expansion, there is a concern that the tips 4a may move and come into contact with each other. However, according to the procedure described above, the protrusions 8a formed by the expansion of the sheet 8 are welded together by heat, which suppresses the loosening of the sheet 8 and prevents situations such as the tips 4a coming into contact with each other or the gap between the tips 4a becoming too narrow.

[0151] Here, as described above, the side of the sheet 8 that holds the workpiece 4 is provided with an adhesive layer for attaching the workpiece 4 and the frame 6. If the protrusions 8a are formed in such a manner that these adhesive layers face each other, it is conceivable that the parts forming the protrusions 8a could be bonded together, for example, by sandwiching the protrusions 8a from the outside.

[0152] However, as shown in the example above, the materials of the sheet 8 are welded together by heating, so regardless of the presence or position of the adhesive layer, the parts forming the protrusions 8a are bonded together. Therefore, even if the workpiece 4 is supported on the underside of the sheet 8 (and thus the adhesive layer is located on the underside of the sheet 8), and the protrusions 8a are formed to be convex downwards (i.e., the adhesive layer is located on the outside of the protrusions 8a which have a U-shaped cross-section, and no adhesive layer is formed on the inner sides facing each other), it is possible to suitably bond the parts of the sheet 8 that form the protrusions 8a together.

[0153] Furthermore, the structures, methods, etc., relating to the above-described embodiments and modifications may be modified and implemented without departing from the scope of the objectives of the present invention. [Explanation of Symbols]

[0154] 2: Workpiece unit, 4: Workpiece (wafer), 4a: Chip 6: Frame, 8: Seat, 8a: Protrusion 10: Processing Unit 12: Sheet holding unit, 12a: Clamping body, 12b: Support member 14: Workpiece holding unit, 14a: Holding surface 16: Seat extension unit, 16a: Main body, 16b: Roller 18: Welding Unit 20: Cover material, 20a: Main surface, 20b: Support member, 20c: Outer surface

Claims

1. Expand the sheet on which the workpiece, with the division starting point formed, is fixed, and divide the workpiece into multiple chips. After the workpiece is divided into multiple chips, a protrusion is formed on a portion of the expanded sheet that protrudes from the surface formed by the other portions. A method for manufacturing a chip, comprising heating the protruding portion to weld together multiple portions of the sheet that are in contact with each other and form the protruding portion.

2. In welding the sheet, A method for manufacturing a chip according to claim 1, wherein the protrusion is heated from one side of the surface facing the outer part of the protrusion, while the other side of the surface facing the outer part of the protrusion is supported by a support member.

3. The sheet is welded with a cover material placed between the heat source used for welding and the workpiece. The method for manufacturing a chip according to claim 2, wherein the cover material comprises a support member that supports the protruding portion.

4. Further comprising the following: after dividing the workpiece and before forming the protrusion, the side of the sheet opposite to the side to which the workpiece is fixed is held by the holding surface of a workpiece holding unit, which is equipped with a member having a holding surface for holding the workpiece. The cover material is placed on the workpiece before the protrusion is formed. The method for manufacturing a chip according to claim 3, wherein the formation of the protrusion is carried out with the sheet sandwiched between the holding surface of the workpiece holding unit and the cover material.

5. The method for manufacturing a chip according to claim 4, wherein, in forming the protrusion, a portion of the sheet is sandwiched between the holding surface of the workpiece holding unit and the cover material, and the area of ​​the sheet surrounding the area sandwiched between the holding surface of the workpiece holding unit and the cover material is further expanded.

6. In welding the sheet, The method for manufacturing a chip according to claim 2, wherein the protrusion is heated by supplying hot air from the side opposite to the support member, with the protrusion in between, toward the protrusion.

7. In forming the protruding portion, The method for manufacturing a chip according to claims 1 to 6, wherein the protruding portion is formed by the sagging of the relaxed sheet.

8. Expanding a sheet on which multiple chips are fixed, and increasing the spacing between the multiple chips, After the workpiece is divided into multiple chips, a protrusion is formed on a portion of the expanded sheet that protrudes from the surface formed by the other portions. A method for increasing the spacing between chips, comprising heating the protruding portion to weld together parts of the sheet that make up the protruding portion.

9. A sheet holding unit that holds a sheet on which the workpiece is fixed, A sheet extension unit that extends the sheet held in the sheet holding unit, A processing apparatus comprising: a sheet expansion unit that heats a protruding portion formed on a part of the sheet expanded by the sheet expansion unit, which protrudes from the rest of the sheet, and a welding unit that welds together multiple parts of the sheet that are in contact with each other by forming the protruding portion.

Images