Chip processing method

Abstract

To provide a chip processing method capable of favorably picking up a plurality of chips by stably lowering the adhesiveness of a sheet.SOLUTION: A chip processing method includes a supporting step of supporting the sheet side of a sheet unit (12) in which a plurality of chips (11) are held on a sheet (10) whose adhesive strength is reduced by irradiation with ultraviolet rays with a support table (20, 26), a pressing step of pressing the chip supported on the support table with a pressing member (30, 40, 50, 62) from above against the sheet, and an ultraviolet irradiation step of irradiating the sheet with ultraviolet rays (UV) to reduce its adhesive strength after the pressing step.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a chip processing method for peeling a plurality of chips from a sheet.

Background Art

[0002] In the manufacture of semiconductor devices and the like, it is often the case that a workpiece (workpiece to be processed) is supported on an adhesive sheet, the workpiece is divided into a plurality of chips, and then each chip is picked up from the sheet. As a method of dividing a workpiece into a plurality of chips, an expand method is known in which tension is applied to a sheet and the sheet is expanded to divide the chips (for example, Patent Document 1 and Patent Document 2).

[0003] When the adhesive force of the sheet is strong, it is difficult to pick up the chips well from the sheet. Therefore, after using a sheet provided with an ultraviolet curable adhesive layer whose adhesive force is reduced by irradiation with ultraviolet rays, before picking up the divided chips, the sheet is irradiated with ultraviolet rays to reduce the adhesive force, thereby making it easier to peel the chips from the sheet.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, before picking up the chips from the sheet, the adhesion of each chip to the sheet was not uniform; there were parts where the chip was floating away from the sheet and parts where the chip was firmly attached. In such cases, when the adhesive strength of the sheet was reduced by irradiating it with ultraviolet light and then picking up the chips from the sheet, it was not possible to reduce the adhesive strength uniformly, resulting in a problem where the chips could not be properly peeled off the sheet during pickup.

[0006] Furthermore, if there was a gap between the chip and the sheet, and oxygen was present in that gap, the effect of reducing adhesive strength during UV irradiation was impaired, resulting in a problem where the adhesive strength did not decrease steadily.

[0007] This invention has been made in view of the above, and aims to provide a chip processing method that can reliably reduce the adhesiveness of a sheet and effectively pick up multiple chips. [Means for solving the problem]

[0008] A chip processing method according to one aspect of the present invention includes a support step of supporting the sheet side of a sheet unit, in which a plurality of chips are held on a sheet whose adhesive strength is reduced by irradiation with ultraviolet light, with a support table, and the support step of the sheet unit supported by the support table Some of the multiple chips The chip Towards the sheet Pressing member Using The device comprises a pressing step of pressing the sheet, and an ultraviolet irradiation step of irradiating the sheet with ultraviolet light after the pressing step to reduce its adhesive strength. ru .

[0009] moreover, Prior to performing the support step, there is an expansion step of expanding the sheet to widen the spacing between the chips. 、 In the pressing step, the chip that has been lifted from the sheet by the expansion step By the pressing member Press it firmly against the sheet to ensure it adheres well.

[0010] After performing the ultraviolet irradiation step, a pickup step of picking up the chip from the sheet may be included.

[0011] A chip processing method according to one aspect of the present invention includes a support step of supporting the sheet side of a sheet unit, in which a plurality of chips are held on a sheet whose adhesive strength is reduced by irradiation with ultraviolet light, with a support table; a pressing step of supplying fluid from the fluid supply holes to the plurality of chips supported on the support table, using a pressing member having a plurality of fluid supply holes that supply fluid toward the chips from a surface facing the surface of the chips, and pressing the chips against the sheet while supplying fluid from the fluid supply holes; an ultraviolet irradiation step of irradiating the sheet with ultraviolet light after the pressing step to reduce its adhesive strength; and an expansion step of expanding the sheet to widen the spacing between the chips before the support step, wherein the pressing step presses the chips that have been lifted from the sheet by the expansion step against the sheet with the pressing member to make them adhere tightly.

[0012] Furthermore, it includes a detection unit that images multiple chips and detects the chips that have lifted off the sheet.

Advantages of the Invention

[0013] According to the chip processing method of the present invention, by performing a pressing step of pressing the chip against the sheet with a pressing member, the adhesiveness of the sheet is stably reduced in the ultraviolet irradiation step, and a plurality of chips can be picked up well.

Brief Description of the Drawings

[0014] [Figure 1] It is a diagram for explaining the expansion step. [Figure 2] It is a diagram for explaining the support step and the pressing step of the first embodiment. [Figure 3] It is a diagram for explaining the support step and the pressing step of the second embodiment. [Figure 4] It is a diagram for explaining the support step and the pressing step of the third embodiment. [Figure 5] It is a diagram for explaining the support step and the pressing step of the fourth embodiment. [Figure 6] It is a diagram for explaining the ultraviolet irradiation step. [Figure 7] It is a diagram for explaining the pickup step.

Modes for Carrying Out the Invention

[0015] The chip processing method according to this embodiment uses a sheet whose adhesive force decreases upon irradiation with ultraviolet light. The method mainly includes supporting a sheet holding a plurality of chips on a support table (supporting step), pressing the chips from above with a pressing member and pressing them against the sheet (pressing step), and irradiating the sheet with ultraviolet light to reduce the adhesive force of the sheet (ultraviolet irradiation step).

[0016] Before performing the supporting step, by dividing the workpiece (workpiece to be processed) on the sheet into a plurality of chips, a sheet unit in which a plurality of chips are held on the sheet can be obtained. Various methods for dividing the workpiece into a plurality of chips are known. As an example, there is a method of expanding (expanding) the sheet.

[0017] FIG. 1 shows an expanding step of forming a plurality of chips by expanding the sheet. The illustrated sheet 10 has a base material layer and an adhesive layer, and is an ultraviolet-curable sheet whose adhesive force of the adhesive layer decreases when irradiated with ultraviolet light. Further, the base material layer of the sheet 10 has the property of softening by heating.

[0018] The workpiece (not shown) before being divided in the expanding step is, for example, a semiconductor wafer. The adhesive layer of the sheet 10 is attached to the back side of the workpiece. The workpiece is supported by an annular frame 13 through the sheet 10, and the workpiece is located inside the opening of the frame 13. The workpiece has a plurality of regions partitioned by division planned lines formed in a grid pattern, and chips 11 are formed in each region. Devices such as electronic circuits are formed on the surface side of the chips 11.

[0019] Preprocessing is performed on the workpiece to facilitate dividing the chips 11 along the division planned lines. As the preprocessing, laser processing or cutting processing can be used. As an example of laser processing, the laser beam is irradiated by focusing the light collection point inside the workpiece to form a modified layer of vulnerability along the division planned line. As an example of cutting processing, a half cut is performed to form a groove with a predetermined depth along the division planned line. Note that the preprocessing is not limited to these examples.

[0020] After the workpiece has been pre-processed, the frame 13 is held by a transport mechanism (not shown in the illustration) and the workpiece and sheet 10 are transported to the expander that performs the expansion step.

[0021] The expanding device has a well-known configuration as described in Patent Documents 1 and 2, so a detailed explanation will be omitted, but it expands a circular sheet radially or a rectangular sheet along its four sides. Note that the shape of the sheet or workpiece is not limited and may be other than circular or rectangular.

[0022] Arrow E in Figure 1 indicates the expansion operation of the sheet 10 by the expander. When the sheet 10 is expanded by the expander, a force is applied that expands the workpiece along with the sheet 10. As a result, the workpiece is divided along the division lines that have been pre-processed to make it easier to divide, and the spacing between the multiple chips 11 widens. The slack in the sheet 10 caused by the expansion is removed as appropriate by using methods such as thermal shrinkage due to heating.

[0023] In this state, a sheet unit 12 is formed in which multiple chips 11 are held on the sheet 10 (see Figure 1). Although each drawing shows the sheet unit 12 with the frame 13 attached, support of the sheet 10 and chips 11 by the frame 13 is not essential. In other words, the present invention can also be carried out with a sheet unit that does not include the frame 13.

[0024] However, the multiple chips 11 held on the sheet 10 do not necessarily adhere uniformly to the sheet 10. Due to factors such as warping of the chips 11 themselves or tension acting on the sheet 10, the chips 11 may partially curl upwards relative to the sheet 10. In this case, the chips 11 will have an uneven distribution of parts that are lifted away from the sheet 10 and parts that are in close contact with the adhesive layer of the sheet 10. When the chips 11 are divided using the expansion of the sheet 10, the peripheral parts of the chips 11 tend to lift away from the sheet 10 more easily than the central parts, as shown in Figure 1.

[0025] If the sheet 10 is exposed to ultraviolet light while the chip 11 is still lifted, the curing state of the adhesive layer of the sheet 10 may become uneven, and the adhesive strength may not decrease steadily. This can lead to problems when picking up the chip 11 from the sheet 10 after ultraviolet light irradiation, where the chip 11 cannot be properly removed from the sheet 10. For example, if the adhesive strength remaining on the sheet 10 is too strong in some areas, the adhesive layer of the sheet 10 may stick to the chip 11 (a so-called adhesive residue) when the chip 11 is picked up, or the chip 11 may be damaged if someone tries to forcibly peel it off the sheet 10.

[0026] One reason for the variation in the curing state of the adhesive layer of sheet 10 is that the optical conditions and various other conditions differ when ultraviolet light is irradiated in areas where the chip 11 is in close contact with sheet 10 and areas where the chip 11 is lifted away from sheet 10.

[0027] For example, the transmittance, absorption rate, and reflectance of the irradiated ultraviolet light differ between the areas where the chip 11 is in close contact with the sheet 10 and the areas where the chip 11 is lifted away from the sheet 10.

[0028] Furthermore, if there is a gap between the chip 11 and the sheet 10, air will enter that gap. The oxygen contained in the air will act to inhibit the effect of reducing the adhesive strength of the sheet 10 when irradiated with ultraviolet light. In other words, if oxygen-containing air enters the gap between the chip 11 and the sheet 10, the adhesive strength of the sheet 10 will not decrease as easily when irradiated with ultraviolet light.

[0029] To prevent such problems, the chip processing method of this embodiment performs a pressing step before the ultraviolet irradiation step, pressing the chip 11 from above with a pressing member to press it against the sheet 10 and eliminate the lifting of the chip 11 relative to the sheet 10. Figures 2 to 5 show four embodiments of the pressing step. In all embodiments, a support step is performed before the pressing step.

[0030] The support step and the pressing step are performed in the pressing device. After removing debris generated during the splitting of the chip 11 in the expansion step, the sheet unit 12 is transported to the pressing device.

[0031] Figure 2 shows the support step and pressing step of the first embodiment. In the support step of the first embodiment, the sheet 10 side of the sheet unit 12 is supported by the support table 20.

[0032] A recess is formed on the upper surface of the support table 20, and a porous plate 21 made of porous material is fixed within the recess of the support table 20. The upper surface of the porous plate 21 is a flat holding surface 22 facing upward. A suction passage 23 is connected to the lower part of the porous plate 21, and the suction passage 23 is connected to a suction source 24. When the suction source 24 is operated, a suction force acts on the porous plate 21 and the holding surface 22 via the suction passage 23.

[0033] A heating unit (heater) 25 is provided inside the support table 20, below the porous plate 21. The heating unit 25 can heat the support table 20 (in particular the holding surface 22 of the porous plate 21).

[0034] The sheet unit 12 is supported by the support table 20 when the sheet 10 is placed on the holding surface 22. The reason for performing the support step is to restrict the movement of the tip 11 and the sheet 10 in the pressing direction when the tip 11 is pressed in the pressing step described later, in order to ensure that the pressed tip 11 is in close contact with the sheet 10. Therefore, in the support step, the support table 20 supports the sheet unit 12 from below on the side with the sheet 10.

[0035] Following the support step, a pressing step is performed. In the pressing step of the first embodiment, a fluid supply nozzle 30 that supplies fluid F to the tip 11 is used as the pressing member. The fluid supply nozzle 30 is positioned above the support table 20. Fluid F is supplied from the fluid supply source 31 to the fluid supply nozzle 30, and the fluid supply nozzle 30 ejects the fluid F downward at a predetermined pressure.

[0036] The fluid F injected from the fluid supply nozzle 30 presses the tip 11, supported by the support table 20, from above, pressing the tip 11 against the sheet 10. The pressed tip 11 eliminates any lifting away from the sheet 10 and adheres evenly to the sheet 10. In addition, the elimination of the lifting of the tip 11 by the pressure from the fluid F prevents outside air from entering between the tip 11 and the sheet 10.

[0037] In the pressing step, the suction source 24 may be operated to hold the sheet unit 12 against the holding surface 22 by suction. Additionally, the effect of pressing the sheet 10 against the holding surface 22 can be obtained by spraying fluid F from above. This allows the pressing step to be performed while stabilizing the sheet unit 12 on the support table 20 so that it does not move.

[0038] Pressing the tip 11 via the fluid F has the advantage of being easy to do without damaging the tip 11. The pressure of the fluid F injected from the fluid supply nozzle 30 is controlled to be strong enough to press the floating tip 11 against the sheet 10, but not so strong that it damages the tip 11.

[0039] The fluid F supplied from the fluid supply nozzle 30 to the tip 11 can be any fluid. For example, air or nitrogen can be used as fluid F. It is also possible to use a liquid such as water as fluid F, but in the case of a liquid, it is necessary to remove (clean) any liquid adhering to the sheet 10 or tip 11 after the pressing step. Therefore, it is preferable to use a gas as fluid F.

[0040] Although Figure 2 shows only one fluid supply nozzle 30, multiple fluid supply nozzles 30 are arranged in a line perpendicular to the plane of Figure 2 to form a line-type nozzle unit 32. The nozzle unit 32 is supported by a horizontal movement unit 33 so as to be movable in the horizontal direction (perpendicular to the direction of the line in which the multiple fluid supply nozzles 30 are arranged). By spraying fluid F from each fluid supply nozzle 30 and moving the nozzle unit 32 horizontally using the horizontal movement unit 33, the fluid F can be sprayed and pressed onto all of the multiple tips 11 in the sheet unit 12. Alternatively, instead of moving the nozzle unit 32, a configuration in which the support table 20 is moved horizontally may be adopted.

[0041] Before the pressing step (support step) and after the pressing step, the nozzle unit 32 is moved by the horizontal movement unit 33 to a detached position away from above the seat unit 12. This allows the seat unit 12 to be attached to and detached from the support table 20.

[0042] The operation of the nozzle unit 32 and the horizontal movement unit 33 is controlled by the control unit 34. The control unit 34 controls the operation of the nozzle unit 32 and the horizontal movement unit 33 so that fluid F is injected at the appropriate pressure to all the tips 11 on the sheet 10.

[0043] To further enhance the effect of the pressing step, heating by the heating unit 25 (heating step) or suction using the suction source 24 may be performed at at least one of the following timings: before, during, or after the pressing step. The control unit 34 also controls these heating and suction functions.

[0044] When the support table 20 is heated by the heating unit 25, heat is transferred to the sheet 10 supported on the holding surface 22, causing it to heat up. The sheet 10 softens due to the heating, which makes it easier for the sheet 10 to conform to and adhere to the chip 11 pressed in the pressing step.

[0045] The heating unit used in the heating step is not limited to the heating unit 25 (Figure 2) consisting of a heater placed on the support table 20. For example, the fluid supply nozzle 30 may also serve as the heating unit, and the chip 11 or sheet 10 may be heated by supplying hot air from the fluid supply nozzle 30.

[0046] When the suction source 24 is activated and a suction force is applied to the holding surface 22, if the sheet 10 is breathable, the suction force is transmitted to the tip 11 through the sheet 10, resulting in the effect of attracting the tip 11 towards the sheet 10.

[0047] Figure 3 shows the support step and pressing step of the second embodiment. In the support step of the second embodiment, the sheet 10 side of the sheet unit 12 is supported by the support table 26. The upper surface of the support table 26 is a flat holding surface 27 facing upward, and the sheet unit 12 is supported by the support table 26 by placing the sheet 10 side on the holding surface 27.

[0048] Following the support step, a pressing step is performed. In the pressing step of the second embodiment, a pressing member 40 positioned above the support table 26 is pressed against the chip 11 from above. The pressing member 40 is a plate-shaped object large enough to cover the entire area of ​​the multiple chips 11, and an elastic member 41 is attached to the lower part of the pressing member 40. The elastic member 41 is made of a material that does not damage the chip 11 when it comes into contact with it. The lower surface of the elastic member 41 is a contact surface 42 that is substantially parallel to the holding surface 27 of the support table 26.

[0049] The pressing member 40 can be moved up and down by the lifting unit 43. Although a detailed illustration of the lifting unit 43 is omitted, it includes a cylinder that supports the pressing member 40 so as to be movable in the vertical direction, and a ball screw that rotates around an axis extending in the vertical direction. When the ball screw is rotated by a motor, a vertical movement force is transmitted to the pressing member 40.

[0050] The operation of the lifting unit 43 is controlled by the control unit 44. In the pressing step, the control unit 44 operates the lifting unit 43 to lower the pressing member 40. The lowered pressing member 40 brings the contact surface 42 of the elastic member 41 into contact with the chip 11, pressing the chip 11, which is supported by the support table 20, from above and pressing the chip 11 against the sheet 10. The pressed chip 11 eliminates any lift from the sheet 10 and adheres evenly to the sheet 10. In addition, the elimination of the lift from the chip 11 by the pressing member 40 prevents outside air from entering between the chip 11 and the sheet 10.

[0051] The control unit 44 controls the amount and speed of movement of the pressing member 40 by the lifting unit 43 so that the pressing member 40 presses the chip 11 with appropriate pressure. For example, data of the thickness values ​​of the sheet 10 and the chip 11 are input to the control unit 44, and based on these thickness values, the control unit 44 calculates the appropriate distance between the holding surface 27 of the support table 26 and the contact surface 42 of the pressing member 40 (elastic member 41). Then, based on this calculated value, the lifting unit 43 is operated in the pressing step so that the holding surface 27 and the contact surface 42 are at the appropriate distance.

[0052] In the pressing step of the second embodiment, a pressing member 40, which is a plate-shaped object, is used to press multiple chips 11 on the sheet 10 together, so pressing can be performed efficiently. The pressing member 40 brings the contact surface 42 of an elastic member 41, which is made of a material that does not damage the chips 11, into contact with the chips 11, so damage to the chips 11 due to pressing can be prevented.

[0053] Alternatively, a heating unit such as the heating unit 25 (see Figure 2) may be placed on the pressing member 40, and the heating step may be performed by heating the chip 11 or sheet 10 from the side of the pressing member 40.

[0054] Figure 4 shows the support step and pressing step of the third embodiment. The support table 26 used in the support step of the third embodiment is the same as that of the second embodiment. The sheet unit 12 is supported by the support table 26 by placing the sheet 10 side on the holding surface 27.

[0055] Following the support step, a pressing step is performed. In the pressing step of the third embodiment, as in the first embodiment, a fluid supply nozzle 50 is used as the pressing member to supply fluid F to the tip 11. The fluid supply nozzle 50 is a member large enough to cover the entirety of the multiple tip 11, and a plurality of fluid supply holes 52 are formed on the lower surface of the fluid supply nozzle 50. Fluid F is supplied from the fluid supply source 51 to the fluid supply nozzle 50, and the fluid F is ejected downward from the plurality of fluid supply holes 52 of the fluid supply nozzle 50 at a predetermined pressure.

[0056] The number and density of the fluid supply holes 52 can be set arbitrarily. For example, by providing multiple fluid supply holes 52 at a pitch smaller than the spacing between the multiple chips 11, the fluid F can be reliably injected towards each chip 11 on the sheet 10 and pressed against the sheet 10.

[0057] The fluid supply nozzle 50 can be raised and lowered vertically by a lifting unit 53. The lifting unit 53 includes a cylinder that supports the fluid supply nozzle 50 so as to be movable vertically, and a ball screw that rotates around an axis that extends vertically. When the ball screw is rotated by a motor, a vertical movement force is transmitted to the fluid supply nozzle 50.

[0058] The operation of the fluid supply nozzle 50 and the lifting unit 53 is controlled by the control unit 54. In the support step, the control unit 54 keeps the fluid supply nozzle 50 at an upper position away from the support table 26. This allows the seat unit 12 to be attached to the holding surface 27 of the support table 26. In the pressing step, the control unit 54 lowers the fluid supply nozzle 50 using the lifting unit 53, bringing the lower surface of the fluid supply nozzle 50 closer to the tip 11 to a predetermined distance. Then, the control unit 54 operates the fluid supply source 51 to supply fluid F and injects the fluid F from the multiple fluid supply holes 52.

[0059] The fluid F injected from the multiple fluid supply holes 52 of the fluid supply nozzle 50 presses the tip 11 of the sheet unit 12 supported on the support table 26 from above, pressing the tip 11 against the sheet 10. The pressed tip 11 eliminates any lifting away from the sheet 10 and becomes evenly in contact with the sheet 10. In addition, the elimination of the lifting of the tip 11 by the pressure from the fluid F prevents outside air from entering between the tip 11 and the sheet 10.

[0060] Furthermore, by using hot air as the fluid F injected from the fluid supply hole 52, the sheet 10 may be softened to make it easier to adhere to the tip 11. In other words, the heating step may be performed by heating the tip 11 and the sheet 10 from the fluid supply nozzle 50 side.

[0061] In the pressing step of the third embodiment, fluid F is injected from multiple fluid supply holes 52 of a fluid supply nozzle 50 large enough to cover multiple chips 11, and multiple chips 11 on the sheet 10 are pressed together, so that pressing can be performed efficiently. Also, similar to the pressing step of the first embodiment, pressing the chips 11 via fluid F allows pressing to be performed without damaging the chips 11.

[0062] Incidentally, the degree of lifting may be uneven among multiple chips 11 on the sheet 10. For example, lifting may occur in a specific area of ​​the sheet 10, while chips 11 do not lift in other areas of the sheet 10. Furthermore, even for individual chips 11, there may be variations in the areas that adhere closely to the sheet 10 and the areas that lift away from the sheet 10.

[0063] The support step and pressing step of the fourth embodiment shown in Figure 5 detect the lifting status of the multiple chips 11 on the sheet 10 and select whether or not to press with the pressing member according to the detection result. The support table 20 used in the fourth embodiment has the same configuration as in the first embodiment and will not be described.

[0064] The sheet unit 12 is equipped with a detection unit 60 that detects the degree of lifting of multiple chips 11 on the sheet 10. For example, an imaging device can be used as the detection unit 60. Chips 11 that are lifted from the sheet 10 and warped appear to have a smaller area in a plan view compared to chips 11 that are in close contact with the sheet 10. Therefore, when the sheet unit 12 is imaged from above (the chip 11 side), the grooves (kerfs) between each chip 11 are wider in the lifted areas and narrower in the areas where there is no lifting.

[0065] The control unit 61 processes the data captured by the detection unit 60 and determines whether or not the chips 11 are lifted and to what extent, based on information such as the groove width between the chips 11. Then, it sets the areas of the sheet unit 12 where it is determined that the chips 11 are lifted as the areas to be pressed. In the case of Figure 5, the area indicated by the symbol Q is the area to be pressed.

[0066] Unlike the detection unit 60 shown in Figure 5, it is also possible to use an imaging device that images the sheet unit 12 from below as the detection unit. In this case, the sheet unit 12 is not placed on the support table 20, but is imaged from below when the bottom of the sheet unit 12 is not covered, or when the sheet unit 12 is supported by another light-transmitting support table. When the sheet unit 12 is imaged from below (the sheet 10 side), the brightness of the pixels in the captured image will differ between the areas where the chip 11 is in close contact with the sheet 10 and the areas where the chip 11 is lifted away from the sheet 10. For example, due to the influence of reflected and transmitted light hitting the sheet unit 12, the areas where the chip 11 is lifted away from the sheet 10 will have lower brightness (darker) than the areas where the chip 11 is in close contact with the sheet 10.

[0067] When an imaging device that captures images of the sheet unit 12 from below is used as the detection unit, the control unit 61 processes the data captured by the detection unit and determines whether or not the chip 11 is lifted and to what extent, based on information such as the brightness distribution of the image. Then, it sets the areas of the sheet unit 12 where it is determined that the chip 11 is lifted as the pressing target area.

[0068] As a different form of the detection unit 60, a measuring device that measures the height position of the chips 11 can also be used. Known measuring devices of this type include those that irradiate an object with a laser beam and receive the reflected light. The control unit 61 determines whether or not the chips 11 are lifted and to what extent, based on the height position information of each chip 11 measured by the detection unit 60. Then, it sets the areas of the sheet unit 12 where it is determined that the chips 11 are lifted as the areas to be pressed.

[0069] Once the area to be pressed has been set, the control unit 61 controls the operation of the pressing member 62 so as to press only the chip 11 in the area to be pressed. The pressing member 62 is sized to locally press a portion of the sheet unit 12, and an elastic member 63 is provided at the bottom of the pressing member 62. The lower surface of the elastic member 63 is a contact surface 64 that contacts the chip 11. The pressing member 62 can move horizontally and vertically via a moving unit 65.

[0070] The control unit 61 uses the moving unit 65 to position the pressing member 62 above the area to be pressed, and then lowers the pressing member 62. The contact surface 64 of the elastic member 63 provided on the pressing member 62 presses the chip 11 included in the area to be pressed from above, pressing it against the sheet 10 and making it adhere tightly.

[0071] If there are multiple areas to be pressed, the above operation is repeated until the chip 11 has been pressed in all of the areas to be pressed.

[0072] In Figure 5, a pressing member 62 of the type in which an elastic member 63 is in contact with the tip 11 is used. However, it is also possible to use a fluid supply nozzle that supplies fluid as a pressing member to perform pressing in the area to be pressed via fluid. In this case, a fluid supply nozzle configured to locally eject fluid over a narrower area than the nozzle unit 32 in Figure 2 or the fluid supply nozzle 50 in Figure 4 may be used.

[0073] Furthermore, although Figure 5 shows a small pressing member 62 capable of individually pressing the chips 11, it is also possible to use a pressing member large enough to press multiple chips 11 together and perform pressing on each target area while adjusting the horizontal position of the pressing member.

[0074] As in the fourth embodiment, by determining the area to be pressed and performing a partial pressing step, pressing is not performed on chips 11 that are not lifting from the sheet 10, thereby reducing the risk of applying load to those chips 11.

[0075] Once the pressing step is complete, the ultraviolet irradiation step shown in Figure 6 is performed. The ultraviolet irradiation step is carried out by an ultraviolet irradiation device, and the sheet unit 12 after the pressing step is transported to the ultraviolet irradiation device.

[0076] The ultraviolet irradiation device includes a support table 70 made of a translucent material. The sheet 10 side of the sheet unit 12 is placed on the holding surface 71, which is the upper surface of the support table 70. Ultraviolet (UV) light is irradiated from an ultraviolet irradiation unit 72 located inside or below the support table 70 toward the holding surface 71. The ultraviolet irradiation unit 72 is composed of multiple light sources arranged in a row, and ultraviolet (UV) light can be irradiated toward almost the entire sheet 10.

[0077] The adhesive layer of sheet 10 hardens and its adhesive strength decreases when exposed to ultraviolet (UV) light. Due to the pressing step performed earlier, each chip 11 in the sheet unit 12 is no longer lifted from sheet 10 and adheres tightly to sheet 10. This allows for a uniform reduction in the adhesive strength of sheet 10 where the chips 11 are in contact with sheet 10. Furthermore, because there are no gaps between each chip 11 and sheet 10, the intrusion of outside air (especially oxygen) is prevented, so the reduction in adhesive strength due to ultraviolet (UV) light is not hindered by oxygen. In other words, the adhesive strength can be reduced uniformly and efficiently across the entire area where sheet 10 holds multiple chips 11.

[0078] Once the UV irradiation step is complete, the pickup step shown in Figure 7 is performed. The pickup step is carried out by a pickup device, which transports the sheet unit 12 after the UV irradiation step is complete to the pickup device.

[0079] The pickup device is equipped with a support table 80, and the sheet 10 side of the sheet unit 12 is placed on the holding surface 81, which is the upper surface of the support table 80. A pickup tool 82, which is capable of vertical and horizontal movement, is brought close to the chip 11 from above. A suction part 83 is provided at the lower end of the pickup tool 82, and the chip 11 can be held by the suction part 83. With the chip 11 held by the suction part 83, the pickup tool 82 is pulled upward. This detaches the chip 11 from the sheet 10.

[0080] As a result of the UV irradiation step, the adhesive strength of the sheet 10 is reduced, making it easy to peel the chips 11 from the sheet 10. In particular, the pressing step increases the adhesion of the chips 11 to the sheet 10, eliminating lifting, and the UV irradiation step successfully reduces the adhesive strength of the sheet 10 uniformly and stably, allowing each chip 11 to be picked up cleanly from the sheet 10.

[0081] Once a chip 11 is picked up from the sheet 10, the pickup tool 82 is moved to a collection unit (not shown in the diagram), and the chip 11 is released from the pickup tool 82 and collected in the collection unit. Once all chips 11 held on the sheet 10 have been picked up and collected, the series of operations of the chip processing method of this embodiment is completed.

[0082] As described above, in the chip processing method of this embodiment, the chip 11 is pressed against the sheet 10 by pressing members (fluid supply nozzles 30, 50, pressing members 40, 62) before the ultraviolet irradiation step is performed, so that the adhesive force of the sheet 10 in the area in contact with the chip 11 can be reliably reduced. As a result, each chip 11 can be picked up well from the sheet 10.

[0083] In the above embodiment, the expansion step (Figure 1) is performed before the support step to divide the chip 11 by expanding the sheet 10, but the step performed before the support step is not limited to the expansion step.

[0084] For example, before the support step, a processing step such as a splitting step may be performed in which the workpiece is divided into multiple chips using a cutting device equipped with a cutting blade. In a cutting device, cutting is performed with a cutting blade while supplying cutting fluid, so cutting fluid may penetrate between the sheet and the chip. In this case, when pressing is performed in the pressing step, the cutting fluid that has penetrated between the sheet and the chip is pushed out and removed. Therefore, even when the chip is split by cutting, the chip processing method to which the present invention is applied is very useful.

[0085] Furthermore, the splitting step performed before the support step may involve splitting the workpiece by irradiating it with a laser beam.

[0086] Furthermore, the embodiments of the present invention are not limited to the embodiments or modifications described above, and may be modified, substituted, or altered in various ways without departing from the spirit of the technical idea of ​​the present invention. Moreover, if the technical idea of ​​the present invention can be realized in a different way by advances in the art or by other derived arts, it may be implemented by that method. Accordingly, the claims cover all embodiments that may fall within the scope of the technical idea of ​​the present invention. [Industrial applicability]

[0087] As described above, applying the chip processing method of the present invention makes it possible to stably reduce the adhesiveness of the sheet and pick up multiple chips effectively, thereby achieving excellent production efficiency in the manufacturing of electronic devices and the like. [Explanation of Symbols]

[0088] 10: Sheet 11: Tip 12: Seat Unit 13: Frame 20: Support Table 21: Porous board 22: Holding surface 23: Suction path 24: Suction source 25: Heating unit 26: Support Table 27: Holding surface 30: Fluid supply nozzle (pressing member) 31 :Fluid supply source 32: Nozzle Unit 33: Horizontal movement unit 34: Control Unit 40: Pressing member 41: Elastic member 42: Contact surface 43: Lifting Unit 44: Control Unit 50: Fluid supply nozzle (pressing member) 51 :Fluid supply source 52:Fluid supply hole 53: Lifting Unit 54: Control Unit 60: Detection unit 61: Control Unit 62: Pressing member 63: Elastic member 64: Contact surface 65: Mobile Unit 70: Support Table 71: Holding surface 72: UV irradiation area 80: Support Table 81: Holding surface 82: Pickup Tool 83: Adsorption part F:Fluid UV: Ultraviolet light

Claims

1. A support step in which a sheet unit, in which multiple chips are held on a sheet whose adhesive strength is reduced by ultraviolet irradiation, is supported on the sheet side by a support table, A pressing step in which some of the multiple chips supported by the support table are pressed against the sheet using a pressing member, After the pressing step is performed, the sheet is irradiated with ultraviolet light to reduce its adhesive strength in an ultraviolet irradiation step, Before performing the support step, The sheet has an expansion step of expanding to widen the spacing between the chips, The chip processing method is characterized in that the pressing step presses the chip, which has been lifted from the sheet by the expansion step, against the sheet using the pressing member to make it adhere tightly.

2. After the ultraviolet irradiation step is performed, The chip processing method according to claim 1, characterized by having a pickup step of picking up the chip from the sheet.

3. A support step of supporting the sheet side of a sheet unit, in which a plurality of chips are held on a sheet whose adhesive strength is reduced by ultraviolet irradiation, with a support table, A pressing step is performed in which a pressing member is used to supply fluid to a plurality of chips supported on the support table, with a pressing member having a plurality of fluid supply holes arranged thereon, which supply fluid from the surface facing the surface of the chip toward the chip, while supplying fluid from the fluid supply holes, and the pressing member is brought into contact with the chip to press the chip against the sheet, After the pressing step is performed, A UV irradiation step in which the sheet is irradiated with ultraviolet light to reduce its adhesive strength, Before performing the support step, The sheet has an expansion step of expanding to widen the spacing between the chips, The chip processing method is characterized in that the pressing step presses the chip, which has been lifted from the sheet by the expansion step, against the sheet using the pressing member to make it adhere tightly.

4. The chip processing method according to claim 1 or 3, further comprising a detection unit that images a plurality of chips and detects the chips that have lifted off the sheet.

Images