Method of dividing a workpiece

Abstract

This invention provides a novel method for dividing a workpiece that can solve various problems caused by the sagging of an expanded sheet without relying on thermal shrinkage. [Solution] The present invention relates to a method for dividing a workpiece used when dividing a workpiece unit, which includes a plate-shaped workpiece on which a dividing portion is provided as the starting point for division, a first frame arranged to surround the workpiece, and an expanded sheet attached to the workpiece and the first frame, wherein the method comprises: a frame arrangement step of placing the first frame and the second frame opposite each other; a division step of dividing the workpiece starting from the dividing portion by expanding the expanded sheet attached to the first frame toward the second frame; and an attachment step of attaching the expanded sheet to the second frame.

Description

Technical Field

[0001] The present invention relates to a method for dividing a plate-shaped workpiece, which is applied when dividing the workpiece.

Background Art

[0002] In electronic devices typified by mobile phones and personal computers, a device chip having devices such as electronic circuits is an essential component. The device chip is obtained, for example, by partitioning a wafer made of a material such as silicon or sapphire into a plurality of regions along a division planned line (street), forming a device in each region, and then dividing the wafer along this division planned line.

[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 penetrates the workpiece is condensed on the division planned line and the portion is modified (see, for example, Patent Document 1). Since the portion modified by the laser beam is brittle, when an external force is applied to the workpiece, the workpiece is divided into a plurality of chips with the division planned line as a boundary.

[0004] When dividing a workpiece by the method as described above, it is common to attach an expand sheet having a property of expanding when a force is applied to the workpiece. For example, when an expand sheet attached to one side of a plate-shaped workpiece is expanded along the surface direction, a force is applied to the workpiece through this expand sheet, and the workpiece is divided. Further, when the expand sheet is further expanded, the gap between adjacent chips is widened, facilitating operations such as picking up the chips.

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

[0006] The expandable sheet is expanded by pressing an expander against it, for example, perpendicular to the surface, with its outer edge fixed to the annular frame. However, since the frame does not expand along with the expandable sheet, the expanded sheet may sag inside the annular frame.

[0007] When the expanded sheet is loose, it may shake during transport, causing adjacent chips to collide and break. Furthermore, the expanded portion of the expanded sheet may contract over time, narrowing the gaps between adjacent chips.

[0008] Therefore, a technique has been proposed in which heat is applied to the portion of the expanded sheet that lies between the workpiece and the annular frame, thereby actively shrinking this portion (see, for example, Patent Document 2). By shrinking the region of the expanded sheet that lies around the workpiece, the expanded sheet remains taut, preventing collisions between adjacent chips. In addition, the expanded 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]

[0009] [Patent Document 1] Japanese Patent Publication No. 2002-192370 [Patent Document 2] Japanese Patent Publication No. 2019-117896 [Overview of the project] [Problems that the invention aims to solve]

[0010] However, the ease with which expanded sheets shrink due to heat varies depending on the material, dimensions, etc. When expanded sheets that do not shrink easily due to heat are used, the problems caused by the sagging of the expanded sheets cannot be solved by the methods described above. Furthermore, even when expanded sheets that shrink easily due to heat are used, the methods described above were not sufficient to solve the problems when the chip size was small.

[0011] The object of the present invention is to provide a novel method for dividing a workpiece that can solve various problems caused by the sagging of an expanded sheet without thermal shrinkage. [Means for solving the problem]

[0012] According to one aspect of the present invention, a method for dividing a workpiece is provided for use when dividing a workpiece unit, which includes a plate-shaped workpiece having a dividing portion that is a starting point for division, a first frame arranged to surround the workpiece, and an expanded sheet attached to the workpiece and the first frame, the method comprising: a frame arrangement step of placing the first frame and the second frame opposite each other; a division step of dividing the workpiece starting from the dividing portion by expanding the expanded sheet attached to the first frame toward the second frame; and an attachment step of attaching the expanded sheet to the second frame.

[0013] Preferably, in the frame placement step, the second frame is positioned inside a container whose interior is connected to the outside through an opening larger than the workpiece but smaller than the workpiece unit, facing the opening, and the workpiece unit including the first frame is positioned such that the workpiece side of the workpiece unit faces the interior side of the container and the opening is closed by the workpiece unit, thereby forming a depressurized space which is a space in which negative pressure is supplied to the interior side by the container and the workpiece unit, and in the splitting step, the depressurized space formed by the container and the workpiece unit is depressurized, thereby expanding the expanded sheet in the direction toward the second frame.

[0014] Preferably, the process further includes a cutting step of cutting the expanded sheet attached to the second frame along the second frame.

[0015] Preferably, in the application step, the expanded sheet is pressed against the second frame by the air pressure outside the container.

[0016] Preferably, in the application step, the expanded sheet is pressed against the second frame by a force separate from the air pressure outside the container. [Effects of the Invention]

[0017] In the method for dividing a workpiece according to one aspect of the present invention, the workpiece is divided by expanding the expandable sheet, and then the expandable sheet is attached to the second frame. As a result, there is no slack in the expandable sheet attached to the second frame. Therefore, according to the method for dividing a workpiece according to one aspect of the present invention, various problems caused by slack in the expandable sheet can be solved without thermal shrinkage. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is an exploded perspective view schematically showing an example of the configuration of a workpiece unit. [Figure 2] FIG. 2 is a cross-sectional view showing an example of the configuration of the dividing device (first embodiment), and schematically shows a state in which a workpiece unit and a second frame are arranged in the dividing device. [Figure 3] FIG. 3 is a flowchart showing an example of a procedure related to a method for dividing a workpiece. [Figure 4] FIG. 4 is a cross-sectional view showing one step of a procedure related to a method for dividing a workpiece, and schematically shows a state in which the workpiece is divided. [Figure 5] FIG. 5 is a cross-sectional view showing another step of a procedure related to a method for dividing a workpiece, and schematically shows a state in which an expand sheet is attached to the second frame. [Figure 6] FIG. 6 is a cross-sectional view showing yet another step of a procedure related to a method for dividing a workpiece, and is a cross-sectional view schematically showing a step in which the expand sheet is cut along the second frame. [Figure 7] FIG. 7 is a cross-sectional view schematically showing the form of a workpiece unit including the workpiece after division supported by an annular second frame. [Figure 8] FIG. 8 is a cross-sectional view showing another example of the configuration of the dividing device (second embodiment). [Figure 9] FIG. 9 is a cross-sectional view schematically showing the steps of dividing a workpiece using the dividing device of FIG. 8 and attaching an expand sheet to the second frame. [Figure 10] FIG. 10 is a cross-sectional view showing yet another example of the configuration of the dividing device (third embodiment). [Figure 11] FIG. 11 is a cross-sectional view schematically showing the steps of dividing a workpiece using the dividing device of FIG. 10 and attaching an expand sheet to the second frame. [Figure 12] FIG. 12 is a cross-sectional view showing yet another example of the configuration of the dividing device (fourth embodiment). [Figure 13] FIG. 13 is a cross-sectional view schematically showing the step of dividing a workpiece using the dividing device of FIG. 10. [Figure 14]Figure 14 is a schematic cross-sectional view showing the process of attaching the expanded sheet to the second frame using the splitting device shown in Figure 10. [Figure 15] Figure 15 is a cross-sectional view showing yet another example (fifth embodiment) of the configuration of the splitting device. [Figure 16] Figure 16 is a schematic cross-sectional view showing the process of dividing a workpiece using the dividing device shown in Figure 15 and attaching the expanded sheet to the second frame. [Modes for carrying out the invention]

[0019] An embodiment (first embodiment) according to one aspect of the present invention will be described with reference to the attached drawings.

[0020] First, the workpiece unit to be handled in this first 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 composed of a workpiece 4, a frame (first frame) 6, and an expanded sheet 8.

[0021] 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.

[0022] The workpiece 4 has been modified by laser processing along the street, and this area functions as the starting point for division when the workpiece 4 is divided (referred to as the "divided portion" in this specification). Note that the method of creating the divided portion in the workpiece 4 is not limited to laser processing. For example, it is also conceivable that the surface of the workpiece 4 is cut with a blade to form grooves, and these grooves become the divided portion.

[0023] 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.

[0024] The workpiece 4 is handled in a frame unit state, held in an annular frame (first frame) 6 as shown in Figure 1, for convenience of handling such as transport and holding. The first 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 first frame 6 that penetrates the first frame 6 in the thickness direction. The diameter of this opening is set to be larger than the diameter of the workpiece 4.

[0025] The workpiece 4 is supported by the first frame 6 via an expanded sheet 8. The expanded sheet 8 is composed of, for example, a circular film-like base material with a diameter larger than the central opening of the first frame 6, and an adhesive layer provided on the base material. The base material is formed from an expandable 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.

[0026] With the workpiece 4 positioned inside the opening of the first frame 6 and surrounded by the first frame 6, the central part of the expanded sheet 8 is attached to the workpiece 4, and the outer periphery of the expanded sheet 8 is attached to the first frame 6, thereby supporting the workpiece 4. In this state, the adhesive surface of the expanded sheet 8 that is not attached to either the first frame 6 or the workpiece 4 is exposed in an annular shape between the outer periphery of the expanded sheet 8 attached to the first frame 6 and the central region of the expanded sheet 8 attached to the workpiece 4.

[0027] Figure 2 is a cross-sectional view showing the configuration of the dividing device 10 according to the first embodiment, schematically showing a state in which the workpiece unit 2 including the first frame 6 is arranged outside the dividing device 10, and the second frame 16 is arranged inside the dividing device 10.

[0028] The splitting device 10 comprises a container 12 and a pressure reducing device 14 connected to the container 12.

[0029] The container 12 of this first embodiment is a flat rectangular box in which the vertical dimension is smaller than the horizontal dimension, and houses the second frame 16 inside, and supports the workpiece unit 2 (see Figure 1) including the first frame 6 and the second frame 16 so that they face each other.

[0030] The second frame 16 is, for example, an annular frame similar to the first frame 6 shown in Figure 1. The second frame 16 is a plate-shaped component made of a metal such as SUS (stainless steel), and an opening is provided in the center of the second frame 16 that penetrates the second frame 16 in the thickness direction. The diameter of this opening is set to be larger than the diameter of the workpiece 4.

[0031] The second frame 16, having the above configuration, supports the workpiece 4 attached to the central part of the expanded sheet 8 by attaching the outer periphery of the expanded sheet 8 to it, similar to the first frame 6, thereby forming a workpiece unit 2' (see Figure 7).

[0032] The inner diameter of the second frame 16 may be the same as the inner diameter of the first frame 6, or it may be smaller than the first frame 6, for example. The step of attaching the expandable sheet 8, described later, to the second frame 16 is easier to perform if the inner diameter of the second frame 16 is smaller than the inner diameter of the first frame 6. However, depending on conditions such as the ease of expanding the expandable sheet 8, the step can also be performed if the inner diameter of the second frame 16 is the same as the inner diameter of the first frame 6, or even if the inner diameter of the second frame 16 is larger than the inner diameter of the first frame 6. There are no particular restrictions on the outer diameter of the second frame 16; it should be a size that can be accommodated in the container 12.

[0033] A second frame support portion 18 is provided at the bottom of the container 12, supporting the second frame 16 approximately parallel to the bottom surface of the container 12. The second frame support portion 18 is, for example, an annular base whose inner diameter of the upper surface is set to be smaller than the outer diameter of the second frame 16. In plan view, the central region of the second frame support portion 18 is a cavity 18b. The upper surface of the annularly formed second frame support portion 18 is used as the support surface 18a, and the second frame 16 can be supported on the support surface 18a such that the central cavity of the second frame support portion 18 and the central region of the second frame 16 overlap in plan view.

[0034] An opening 12a is provided at the top of the container 12, and the inside of the container 12 is connected to the outside through this opening 12a. The dimensions of the opening 12a are set to be smaller than the workpiece unit 2 shown in Figure 1 (i.e., smaller than the outer diameter of the first frame 6 that constitutes the workpiece unit 2) and larger than the plate-shaped workpiece 4 included in the workpiece unit 2.

[0035] The workpiece unit 2 is supported in the upper part of the container 12, which is provided with such an opening 12a, such that the workpiece 4 is located in the opening 12a and the first frame 6 is located at the edge of the opening 12a. That is, the upper part of the container 12 functions as a first frame support portion 20 that supports the workpiece unit 2 including the first frame 6, and the upper surface of the container 12 functions as a support surface 20a that supports the first frame 6. When the workpiece unit 2 is supported by the first frame support portion 20, the opening 12a overlaps with the central part of the workpiece unit 2 in a plan view and is closed by the workpiece unit 2.

[0036] The pressure reducing device 14 is a device such as a vacuum pump connected to the container 12, and is designed to supply negative pressure inside the container 12. When the pressure reducing device 14 is activated with the opening 12a blocked by the workpiece unit 2, the space formed by the container 12 and the workpiece unit 2 is depressurized.

[0037] In this specification, the terms "inside" and "outside" of the container 12 are defined by the range over which pressure affects them, and refer to the space where negative pressure is supplied by the depressurization device 14 (hereinafter referred to specifically as the "depressurization space" in this specification) and the space outside of that space where external atmospheric pressure acts, respectively. Therefore, the outside of the container 12 does not necessarily mean the area outside the walls that make up the container 12. Even inside the walls that make up the container 12, any space that is not affected by the negative pressure supplied by the depressurization device 14 is defined as the outside.

[0038] When dividing the workpiece 4, as shown in Figure 2, the workpiece unit 2 including the first frame 6 and the workpiece 4 is supported on the outside of the container 12 (on the support surface 20a of the first frame support part 20), while the second frame 16 is supported on the inside of the container 12 (on the support surface 18a of the second frame support part 18).

[0039] In this state, the second frame 16 faces the opening 12a provided at the top of the container 12. The workpiece unit 2, including the first frame 6, is positioned on the first frame support 20 such that the workpiece 4 side faces the inside of the container 12, and the opening 12a is closed by the workpiece unit 2. A reduced pressure space SP is formed on the inside of the container 12 by the wall of the container 12 and the workpiece unit 2.

[0040] The second frame 16 is located on the inside of the container 12, and the first frame 6 located on the outside and the second frame 16 located on the inside face each other.

[0041] The dividing device 10 includes a cutter 22 in addition to the container 12 and the depressurization device 14. In a procedure described later, the cutter 22 moves in a circular motion along the annular upper surface of the second frame 16 with its cutting edge in contact with the upper surface of the second frame 16, thereby cutting the expanded sheet 8 attached to the upper surface of the second frame 16.

[0042] The process of dividing the workpiece 4 using the dividing device 10 of the first embodiment described above will be explained with reference to Figures 2, 3 and 4 to 7. Figure 3 is a flowchart showing an example of the procedure for dividing a workpiece, and Figures 4 to 7 are diagrams showing each step or the state of the workpiece in the procedure shown in Figure 3.

[0043] Figure 4 is a schematic cross-sectional view showing the workpiece 4 after it has been divided. Figure 5 is a cross-sectional view showing the expanded sheet 8 attached to the second frame 16. Figure 6 is a schematic cross-sectional view showing the process of cutting the expanded sheet 8 along the second frame 16. Figure 7 is a schematic cross-sectional view showing the form of the workpiece unit 2' including the divided workpiece 4 supported by the annular second frame 16.

[0044] First, as shown in Figure 2, the workpiece unit 2, including the first frame 6, and the second frame 16 are placed in the container 12 (frame placement step S10). In this state, the workpiece unit 2 is supported by the first frame support portion 20 so as to cover the opening 12a, while the second frame 16 is supported by the second frame support portion 18 inside the container 12 so as to face the opening 12a, and the first frame 6 and the second frame 16 face each other.

[0045] The workpiece unit 2 is configured such that the workpiece 4 is supported on the first frame 6 via an expanded sheet 8 (see Figure 1). The workpiece unit 2 is positioned on the first frame support section 20 such that the adhesive surface of the expanded sheet 8 and the workpiece 4 attached thereto face downwards (towards the inside of the container 12) relative to the base material of the expanded sheet 8, and face the lower second frame 16.

[0046] The opening 12a provided in the center of the first frame support portion 20 is closed by the workpiece unit 2, and a reduced pressure space SP is formed on the inside of the container 12 by the container 12 and the workpiece unit 2.

[0047] Next, the workpiece 4 included in the workpiece unit 2 is divided (dividing step S20). In the frame arrangement step S10, a reduced pressure space SP is formed inside the container 12 by the container 12 and the workpiece unit 2, and a pressure reducing device 14 is connected to this reduced pressure space SP. When the pressure reducing device 14 is activated, negative pressure is supplied to the reduced pressure space SP, and the pressure reducing space SP is reduced.

[0048] When the pressure reduction space SP is reduced, the pressure difference between the pressure reduction space SP and the outside causes the expandable sheet 8 of the workpiece unit 2, which is provided to close the opening 12a, to expand in the direction toward the inside of the container 12, i.e., toward the second frame 16, as shown in Figure 4. As the expandable sheet 8 attached to the workpiece 4 expands, stress is generated in the workpiece 4, and the workpiece 4 is divided starting from the dividing section provided in the workpiece 4.

[0049] If the depressurization continues after the workpiece 4 has been divided, the expandable sheet 8 will expand further, and a portion of it will reach the position of the second frame 16 located inside the container 12. Of the expandable sheet 8, the area that expands is the area inside the outer periphery attached to the first frame 6, and the workpiece 4 is attached to the central part of this area. In this expanded portion, the area surrounding the workpiece 4 has its adhesive surface exposed facing downward (facing the second frame 16, which is located below the workpiece unit 2). As the depressurization continues, the expandable sheet 8 expands downward, and its exposed area comes into contact with the second frame 16. If the depressurization continues further, as shown in Figure 5, this area will be pressed against the second frame 16 by the air pressure outside the container 12 and attached (attachment step S30).

[0050] Once the expandable sheet 8 is sufficiently attached to the second frame 16, the decompression device 14 is deactivated, and the pressure in the decompressed space SP is returned to atmospheric pressure. The expandable sheet 8, which had expanded due to the pressure difference, attempts to contract, and this force (restoring force) acts in a direction that would cause it to peel away from the second frame 16. However, if the expandable sheet 8 is attached to the second frame 16 with sufficiently strong adhesive force, the restoring force will not cause the expandable sheet 8 to detach from the second frame 16.

[0051] Next, the expanded sheet 8 attached to the second frame 16 is cut along the second frame 16 (cutting step S40). As shown in Figure 6, the tip of the cutter 22 is applied to the back of the adhesive side of the expanded sheet 8, which is attached to the second frame 16 with its adhesive side in contact with it. In this state, the cutter 22 goes around the top surface of the annular second frame 16, and the expanded sheet 8 is cut out.

[0052] Regarding the cutting of the expanded sheet 8 by the cutter 22, the cutter 22 may be inserted into the container 12 while the second frame 16 remains supported by the second frame support 18, so that the expanded sheet 8 is cut inside the container 12. Alternatively, the expanded sheet 8 may be cut while the second frame 16, to which the expanded sheet 8 is attached, is removed from the second frame support 18.

[0053] In this way, a portion of the expanded sheet 8 to which the workpiece 4 is attached is cut out from the workpiece unit 2 including the first frame 6 and attached to the second frame 16, thereby forming a workpiece unit 2' including the second frame 16 as shown in Figure 7.

[0054] Thus, in the procedure described above, a portion of the expanded sheet 8 (the outer periphery) remains attached to the frame (first frame 6) that constitutes the original workpiece unit 2, while another portion (the part inside the outer periphery attached to the first frame 6) is expanded. This expanded portion is then attached to another frame (second frame 16), and the workpiece 4, along with the expanded expanded sheet 8, is transferred to the second frame 16.

[0055] In the workpiece unit 2' thus formed, the expanded sheet 8 is attached to the second frame 16 in an expanded state, so the tension generated by the expansion is maintained in the expanded sheet 8, and the expanded sheet 8 does not sag or contract significantly. After the workpiece 4 is divided, the gaps between each piece (chip) of the workpiece 4 that were widened by the expansion of the expanded sheet 8 do not shrink again, and collisions between adjacent pieces of the workpiece 4 are also suppressed.

[0056] In conventional methods of dividing a workpiece by expanding an expandable sheet, the expanded sheet remains attached to the same frame as the workpiece after expansion, leading to the aforementioned problems caused by sagging and subsequent re-shrinking of the expanded sheet. According to the procedure described above, after the workpiece 4 is divided by the expansion of the expanded sheet 8, the expanded sheet 8 is transferred to another frame (second frame 16) while still expanded, thereby suppressing the occurrence of problems due to sagging and re-shrinking. Furthermore, there is no need to apply heat to shrink the sagging expanded sheet 8.

[0057] In this explanation, the first frame 6 and the second frame 16 are described as being configured as annular frames. However, these frames constituting the workpiece units 2 and 2' do not necessarily have to be annular; they just need to be configured to support the workpiece 4 by attaching the expanded sheet 8 to them. For example, these frames may be formed in a C-shape.

[0058] However, with respect to the first frame 6 in particular, when the pressure is reduced by the pressure reducing device 14, it is necessary to take measures to maintain the airtightness of the pressure reducing space SP, which is composed of the container 12 and the workpiece unit 2, to the extent that the pressure reducing space SP can be reduced without any problems. For example, possible measures include forming the contact portion of the container 12 with the workpiece unit 2 in a shape corresponding to the shape of the first frame 6 so that the gap between the two is as small as possible, or placing a flexible packing between the two.

[0059] For the above procedure to be carried out without problems, the positional relationship of each item, particularly the distance between the workpiece unit 2 and the second frame 16, must be appropriately set according to various conditions such as the dimensions of each part constituting the workpiece unit 2 (workpiece 4, first frame 6, and expanded sheet 8) and the second frame 16, the crackability of the workpiece 4, and the elasticity of the expanded sheet 8.

[0060] According to the inventors' research, for example, if a ring frame with an inner diameter of approximately 12 inches is used as the first frame 6 and a ring frame with an inner diameter of approximately 8 inches is used as the second frame 16, and the distance between the two is set to approximately 3 cm, it has been demonstrated that the division of the workpiece 4 and its transfer to the second frame 16 can be suitably performed by the expansion of the expanded sheet 8 due to reduced pressure. However, this is merely one example, and the dimensions of each frame and the distance between the frames can be changed in various ways.

[0061] Figure 8 is a cross-sectional view showing another example of the configuration of the splitting device. Figure 9 is a schematic cross-sectional view showing the process of splitting the workpiece 4 and attaching the expanded sheet 8 to the second frame 16 using the splitting device of Figure 8.

[0062] The splitting device 30 of the second embodiment shown in Figures 8 and 9 is similar to the splitting device 10 of the first embodiment (see Figure 2) in that a second frame support portion 34 is provided inside the container 32, and the upper surface of the container 32, which has an opening 32a, functions as a first frame support portion 36. However, the splitting device 30 of this second embodiment differs from the splitting device 10 of the first embodiment in that it is provided with an opening / closing portion 38 inside the container 32.

[0063] As shown in Figure 8, in the splitting device 30, the workpiece unit 2, including the first frame 6, and the second frame 16 are supported so as to face each other. The opening / closing section 38 is provided in the container 32 so as to separate the workpiece unit 2 and the second frame 16, and is openable and closable.

[0064] When the opening / closing section 38 is closed, the reduced pressure space SP formed by the container 32 and the workpiece unit 2 is divided into a region on the workpiece unit 2 side (first frame support section 36 side) and a region on the second frame 16 side (second frame support section 34 side), as shown in Figure 8. The pressure reducing device 14 is connected to the second frame 16 side of the reduced pressure space SP divided by the opening / closing section 38.

[0065] When dividing the workpiece 4 and replacing the expanded sheet 8 on the second frame 16, first, as shown in Figure 8, the workpiece unit 2 is supported by the first frame support 36 and the second frame 16 is supported by the second frame support 34. When the opening / closing section 38 is closed, the area of ​​the reduced pressure space SP formed by the workpiece unit 2 and the container 32 on the second frame 16 side, to which the pressure reducing device 14 is connected, is isolated from the area on the workpiece unit 2 side. In this state, when the pressure reducing device 14 is activated, negative pressure is supplied only to the area on the second frame 16 side, and the pressure in that area is reduced.

[0066] Once the pressure reduction is complete, the opening / closing section 38 is opened, and the negative pressure that was supplied to the area on the second frame 16 side extends to the area on the workpiece unit 2 side. Due to the pressure difference between this area and the external atmospheric pressure, the expanded sheet 8 of the workpiece unit 2 expands to the inside of the container 32, as shown in Figure 9. In this way, similar to the first embodiment described above (see Figures 2 and 4 to 7), the workpiece 4 is divided and the expanded sheet 8 is reattached to the second frame 16.

[0067] In this second embodiment of the splitting device 30, negative pressure is instantaneously supplied to the region of the reduced-pressure space SP facing the expanded sheet 8 by opening the opening / closing section 38. For example, compared to the procedure in the first embodiment, the expansion of the expanded sheet 8 is performed at high speed, so the stress generated in the workpiece 4 increases rapidly, which is expected to enable more efficient splitting. In other words, it may be possible to split the workpiece 4 even if the amount of expansion of the expanded sheet 8 is relatively small.

[0068] For example, in the first embodiment, in which the expanded sheet 8 is expanded at a relatively slow speed by supplying negative pressure from the depressurizing device 14, a distance of about 3 cm is required between the first frame 6 and the second frame 16 in order to reliably divide the workpiece 4, and the amount of expansion of the expanded sheet 8 is required in proportion to that distance. However, in this second embodiment, it is expected that the workpiece 4 can be divided even if the distance between the first frame 6 and the second frame 16 is shorter.

[0069] This offers several advantages, such as the ability to miniaturize the container 32 that makes up the splitting device 30, reduce the amount of pressure required by the pressure reducing device 14, save time and energy required for splitting, and use a material with relatively low elasticity as the expanded sheet 8.

[0070] Figure 10 is a cross-sectional view showing yet another example of the configuration of the splitting device. Figure 11 is a schematic cross-sectional view showing the process of splitting the workpiece 4 and attaching the expanded sheet 8 to the second frame 16 using the splitting device of Figure 10.

[0071] The splitting device 40 of the third embodiment shown in Figures 10 and 11 is similar to the splitting device 10 of the first embodiment (see Figure 2) in that a second frame support portion 44 is provided inside the container 42, and a workpiece unit 2 including the first frame 6 is supported by the first frame support portion 46 so as to face the second frame 12, and a reduced pressure space is formed inside by the workpiece unit 2 and the container 42.

[0072] However, in the case of the dividing device 40 of this third embodiment, an opening / closing part 48 is provided on the outside of the space (reduced pressure space SP1) formed by the workpiece unit 2 and the wall of the container 42, and the opening / closing part 48 further forms a reduced pressure space SP2 on the outside of the reduced pressure space SP1.

[0073] The first frame support portion 46 is located between the reduced pressure space SP1 and the reduced pressure space SP2, and an opening 42a is provided in the center of the first frame support portion 46. When the workpiece unit 2 is supported by the first frame support portion 46, the opening 42a is closed by the workpiece unit 2.

[0074] The reduced pressure space SP1 is formed by the walls of the container 42 and the workpiece unit 2, and the second frame support 44 is located inside the reduced pressure space SP1. The reduced pressure space SP2 is formed by the walls of the container 42, the workpiece unit 2 supported by the first frame support 46, and the opening / closing section 48. The reduced pressure space SP1 and the reduced pressure space SP2 are separated by the workpiece unit 2. The reduced pressure space SP2 is connected to or partitioned from the outside space by opening and closing the opening / closing section 48.

[0075] The pressure reducing device 14 is connected to both the pressure reducing spaces SP1 and SP2 and is configured to supply negative pressure to them.

[0076] When dividing the workpiece 4 and replacing the expanded sheet 8 on the second frame 16, first, as shown in Figure 10, the workpiece unit 2 is supported by the first frame support 46 and the second frame 16 is supported by the second frame support 44. The opening / closing section 48 is closed, and negative pressure is supplied from the pressure reducing device 14 to both the pressure reducing spaces SP1 and SP2. Subsequently, when the opening / closing section 48 is opened, the pressure reducing space SP2 is connected to the outside space, and the negative pressure in the pressure reducing space SP2 is released.

[0077] As the depressurized space SP2 is returned to atmospheric pressure, the depressurized space SP1 remains under reduced pressure, causing the expandable sheet 8 of the workpiece unit 2, located between the depressurized spaces SP1 and SP2, to expand toward the depressurized space SP1. The workpiece 4 attached to the expandable sheet 8 is divided, and as the expandable sheet 8 expands further, it becomes attached to the second frame 16 supported within the depressurized space SP1.

[0078] Even when the pressure is reduced using this method, similar to the second embodiment described above (see Figures 8 and 9), the rapid expansion of the expanded sheet 8 generates a sudden stress in the workpiece 4, enabling efficient division of the workpiece 4.

[0079] Figure 12 is a cross-sectional view showing yet another example of the configuration of the splitting device. Figures 13 and 14 are schematic cross-sectional views showing the process of splitting the workpiece 4 and attaching the expanded sheet 8 to the second frame 16 using the splitting device of Figure 12, respectively.

[0080] The dividing device 50 of the fourth embodiment shown in Figures 12 to 14 is substantially the same as that of the first embodiment (see Figure 2) in terms of the configuration and arrangement of the container 52, the second frame support part 54, and the first frame support part 56. However, it differs from the first embodiment in that the second frame support part 54 is configured to support the second frame 16 so that it can move up and down.

[0081] When the workpiece 4 is divided and the expanded sheet 8 is attached to the second frame 16, if the depressurization device 14 is activated while the workpiece unit 2 is supported by the first frame support part 56, negative pressure is supplied to the depressurization space SP inside the container 52, causing the expanded sheet 8 to expand through the opening 52a toward the second frame 16 supported inside the container 52. The second frame support part 54 can expand and contract vertically, allowing the second frame 16 to be moved closer to or further away from the workpiece unit 2 provided on the first frame support part 56.

[0082] In the dividing device 50 of this fourth embodiment, the mechanism for dividing the workpiece 4 and replacing the expanded sheet 8 with the second frame 16 is the same as that of the dividing devices 10, 30, and 40 of the first to third embodiments described above. That is, these processes are carried out by expanding the expanded sheet 8.

[0083] In this case, when dividing the workpiece 4, it is sometimes desirable for the distance between the workpiece unit 2 and the second frame 16 to be relatively large. This is because, in order for the workpiece 4 to be divided, sufficient stress must be generated in the workpiece 4 by the expansion of the expandable sheet 8, and the stress generated in the workpiece 4 will, in principle, increase as the amount of expansion of the expandable sheet 8 increases.

[0084] Sufficient space is required for the expandable sheet 8 to expand fully. For example, if the expandable sheet 8 comes into contact with the second frame 16 before it expands and the workpiece 4 is divided, the second frame 16 may prevent the expandable sheet 8 from expanding any further.

[0085] On the other hand, when replacing the expanded sheet 8 with the second frame 16, it is sometimes desirable for the distance between the workpiece unit 2 and the second frame 16 to be relatively close. This is because the force generated as a result of the expansion of the expanded sheet 8 may hinder the adhesion of the adhesive surface of the expanded sheet 8 to the second frame 16.

[0086] For example, in the state shown in Figure 5, the expanded sheet 8 is expanding while its adhesive surface is attached to the surface of the second frame 16. When the supply of negative pressure to the depressurized space SP is stopped and the pressure inside the depressurized space SP is returned to atmospheric pressure, the expanded expanded sheet 8 attempts to contract, and this force (restoring force) pulls the expanded sheet 8 attached to the second frame 16 towards the first frame 6, attempting to detach it from the second frame 16. In principle, this restoring force is greater the greater the amount of expansion of the expanded sheet 8.

[0087] The amount of expansion required for the expanded sheet 8 to reach the second frame 16 from the first frame 6 and be attached to the second frame 16 increases as the distance between the workpiece unit 2, which includes the first frame 6, and the second frame 16 increases.

[0088] Therefore, in the fourth embodiment of the splitting device 50 shown in Figures 12 to 14, the relative distance between the workpiece unit 2 supported by the first frame support 56 and the second frame 16 supported by the second frame support 54 can be changed by expanding and contracting the second frame support 54.

[0089] Furthermore, as the mechanism for extending and retracting the second frame support section 54, any suitable mechanism may be adopted, such as a mechanism using screws, a mechanism using a coil spring, or a hydraulic mechanism.

[0090] When dividing the workpiece 4, first, as shown in Figure 12, the workpiece unit 2 is supported by the first frame support 56, and the second frame 16 is supported by the second frame support 54. When negative pressure is supplied to the reduced pressure space SP from the reduced pressure device 14, as shown in Figure 13, the expanded sheet 8 of the workpiece unit 2 expands through the opening 56a toward the reduced pressure space SP inside the container 52.

[0091] At this time, the second frame support 54 is retracted, and the second frame 16 is retracted to the bottom of the container 52, away from the first frame support 56. Therefore, the expansion of the expandable sheet 8 is not hindered by the second frame 16 or the second frame support 54, and the workpiece 4 is reliably divided by the sufficient expansion of the expandable sheet 8.

[0092] Once the workpiece 4 is divided, the second frame support portion 54 extends as shown in Figure 14, lifting the second frame 16 and bringing it closer to the first frame support portion 56. The second frame 16 is pressed against the adhesive surface of the expanded sheet 8, and the expanded sheet 8 is attached to the second frame 16.

[0093] At this time, the pressure reduction space SP may be further reduced in conjunction with the extension of the second frame support portion 54. In this case, the expanded sheet 8 is further expanded and pressed more firmly against the second frame 16, thereby further promoting adhesion.

[0094] As described above, the dividing device 50 of this fourth embodiment can suitably perform each process by varying the distance between the workpiece unit 2 supported by the first frame support portion 56 and the second frame 16 supported by the second frame support portion 54 between a distance suitable for dividing the workpiece 4 and a distance suitable for attaching the expanded sheet 8 to the second frame 16.

[0095] Figure 15 is a cross-sectional view showing yet another example of the configuration of the splitting device. Figure 16 is a schematic cross-sectional view showing the process of splitting the workpiece 4 and attaching the expanded sheet 8 to the second frame 16 using the splitting device of Figure 15.

[0096] The splitting device 60 of the fifth embodiment shown in Figures 15 and 16 comprises a second frame support section 62 that supports the second frame 16, a first frame support section 64 that supports the workpiece unit 2 including the first frame 6 so as to be opposite the second frame support section 62, and an expander 66. The first frame support section 64 is a plate-shaped base with a circular opening 64a in the center, and the workpiece unit 2 is supported on the upper surface (support surface 64b) such that the expanded sheet 8 and the workpiece 4 attached thereto overlap in the opening 64a.

[0097] The first frame support portion 64 is located above the second frame support portion 62, and both are supported such that the workpiece unit 2 is located above the second frame 16.

[0098] An expander 66 is provided above the first frame support portion 64. The expander 66 contacts the central part of the workpiece unit 2 supported by the first frame support portion 64 from above, and expands the expanded sheet 8 that constitutes the workpiece unit 2 toward the second frame 16 located below.

[0099] The expander 66 is, for example, an airbag with a dome-shaped form that is convex downwards, and is configured to inflate when gas is introduced into the inside of a flexible bag-like material. When the expander 66 inflates downwards while in contact with the expanded sheet 8 from above, the expanded sheet 8 expands as a result of the inflation.

[0100] Unlike the dividing devices 10, 30, 40, and 50 of the first to fourth embodiments, the dividing device 60 of this fifth embodiment does not require structures such as containers 12, 32, 42, and 52 for forming the reduced-pressure spaces SP, SP1, and SP2. The reduced-pressure device 14 is also unnecessary because the expanded sheet 8 is expanded by the expander 66 without the need for reduced pressure.

[0101] Furthermore, if a space is formed between the components constituting the splitting device 60 and the workpiece unit 2 supported by the first frame support portion 64, a structure such as a hole that connects the space to the outside may be provided to prevent the pressure inside the space from becoming too high due to the pressing by the expander 66.

[0102] When dividing the workpiece 4 and replacing the expanded sheet 8 with the second frame 16, first, as shown in Figure 15, the workpiece unit 2 is supported by the first frame support 64, and the second frame 16 is supported by the second frame support 62. Then, as shown in Figure 16, the expander 66 contacts the expanded sheet 8 from above the workpiece unit 2 supported by the first frame support 64.

[0103] The expanded sheet 8 is pressed by the expander 66 and expands downward through the opening 64a. As the expanded sheet 8 expands, the workpiece 4 attached to the expanded sheet 8 is divided. As the expansion of the expanded sheet 8 by the expander 66 continues, the expanded sheet 8 is pressed against the second frame 16 located below it, and the adhesive surface of the expanded sheet 8 adheres to the second frame 16.

[0104] Next, the expander 66 retracts upward, the expanded sheet 8 is cut along the annular second frame 16, and the transfer of the expanded sheet 8 from the first frame 6 to the second frame 16 is completed.

[0105] Thus, in the dividing device 60 of this fifth embodiment, the expansion of the expanded sheet 8 and the resulting division of the workpiece 4 are performed by a force separate from the air pressure outside the container (pressure by the expanded sheet 8). Furthermore, the attachment of the expanded sheet 8 to the second frame is also performed by pressing the expanded sheet 8 against the second frame 16 with a force separate from the air pressure outside the container (pressure by the expanded sheet 8).

[0106] Although the case where the expander 66 is configured as an airbag has been described here, the configuration of the expander 66 is not limited to this. Other forms of expander 66 may be used as long as they allow for the suitable expansion of the expandable seat 8 as described above.

[0107] For example, the expander 66 may be an article made of, for example, a flexible porous resin, and having at least a portion (this portion referred to as the "convex portion") of a curved surface that is convex outward. The expanded sheet 8 is expanded by bringing the convex portion of the expander 66 into contact with the expanded sheet 8 from above and then pressing down on the expander 66.

[0108] In addition to the embodiments described above, various mechanisms may be employed for expanding the expanded sheet 8. For example, in a dividing device like the third embodiment, it is theoretically possible to expand the expanded sheet 8 by pressurizing the space corresponding to the upper reduced pressure space S2. Furthermore, it is also possible to, for example, divide the workpiece 4 by expanding the expanded sheet 8 through reduced pressure, and then, when attaching the expanded sheet 8, press the expanded sheet 8 and the second frame 16 against each other using a method other than reduced pressure.

[0109] Furthermore, the structures, methods, etc., of the embodiments and modifications described above may be modified and implemented without departing from the scope of the present invention. [Explanation of Symbols]

[0110] 2: Workpiece unit, 2': Workpiece unit 4: Workpiece, 6: Frame (first frame), 8: Expanded sheet 10: Dividing device, 12: Container, 12a: Opening, 14: Pressure reducing device 16: Frame (2nd frame) 18: Second frame support section, 18a: Support surface, 18b: Cavity 20: First frame support section, 20a: Support surface 22: Cutter 30: Dividing device, 32: Container, 32a: Opening 34: Second frame support section, 36: First frame support section, 38: Opening / closing section 40: Dividing device, 42: Container, 42a: Opening 44: Second frame support section, 46: First frame support section, 48: Opening / closing section 50: Dividing device, 52: Container, 52a: Opening 54: Second frame support section, 56: First frame support section 60: Dividing device, 62: Second frame support part 64: First frame support section, 64a: Opening, 64b: Support surface, 66: Expander S: Reduced pressure space, S1: Reduced pressure space, S2: Reduced pressure space

Claims

1. A method for dividing a workpiece unit, which includes a plate-shaped workpiece with a dividing section that serves as the starting point for division, a first frame arranged to surround the workpiece, and an expanded sheet attached to the workpiece and the first frame, wherein the method is used when dividing the workpiece, A frame arrangement step in which the first frame and the second frame are placed facing each other, A dividing step in which the workpiece is divided starting from the dividing portion by expanding the expanded sheet attached to the first frame toward the second frame, A method for dividing a workpiece, comprising the step of attaching the expanded sheet to the second frame.

2. In the frame placement step, a second frame is positioned inside a container whose interior is connected to the outside through an opening that is larger than the workpiece but smaller than the workpiece unit, facing the opening. By arranging the workpiece unit, including the first frame, such that the workpiece side of the workpiece unit faces the interior side of the container, and the opening is closed by the workpiece unit, a reduced pressure space is formed, which is a space in which negative pressure is supplied to the interior side by the container and the workpiece unit. In the splitting step, the expanded sheet is expanded toward the second frame by reducing the pressure in the reduced-pressure space formed by the container and the workpiece unit. The method for dividing a workpiece according to claim 1.

3. The method for dividing a workpiece according to claim 1, further comprising a cutting step of cutting the expanded sheet attached to the second frame along the second frame.

4. The method for dividing a workpiece according to any one of claims 1 to 3, wherein in the application step, the expanded sheet is pressed against the second frame by the air pressure outside the container.

5. The method for dividing a workpiece according to any one of claims 1 to 3, wherein in the application step, the expanded sheet is pressed against the second frame by a force separate from the external air pressure of the container.

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