Semiconductor bare chip pickup device and semiconductor bare chip pickup method

Abstract

The present invention provides a semiconductor bare chip pickup device and a semiconductor bare chip pickup method, which can suppress damage to the semiconductor bare chip when picking up the semiconductor bare chip from a wafer sheet. In the semiconductor bare chip pickup device (100), the adsorption surface (22a) that adsorbs the wafer sheet (12) is a curved surface that is convexly curved upward. After the control unit (70) raises the carrier (20) to push the wafer sheet (12), the interior of the carrier (20) is set to a vacuum state so that the wafer sheet (12) is adsorbed on the adsorption surface (22a). After the wafer sheet (12) is adsorbed on the adsorption surface (22a), the moving element (30) is protruded from the adsorption surface (22a) and the chuck (18) is used to pick up the semiconductor bare chip (15) from the wafer sheet (12).

Description

Technical Field

[0001] The present invention relates to a structure of a semiconductor bare chip picking device for picking up semiconductor bare chips from a wafer sheet and a semiconductor bare chip picking method. Background Art

[0002] Semiconductor bare dies are manufactured by cutting 6-inch or 8-inch wafers into specified sizes. During cutting, a wafer sheet is attached to the backside, and the wafer is cut from the front side using a dicing saw or other method to prevent the cut semiconductor bare dies from becoming scattered. At this point, the wafer sheet attached to the backside is slightly incised but not cut, retaining the individual semiconductor bare dies. The cut semiconductor bare dies are then individually removed from the wafer sheet and sent to subsequent steps, such as die bonding.

[0003] As a method for picking up semiconductor bare chips from a wafer sheet, the following method has been proposed: using a carrier having a spherical adsorption surface to push up the wafer sheet, and vacuum-adsorbing the wafer sheet to its adsorption surface, using a push pin arranged inside the carrier to push up the wafer sheet in a penetrating manner, pushing up the semiconductor bare chip attached to the upper surface of the wafer sheet from the bottom, and using a chuck to pick up the semiconductor bare chip (for example, refer to patent document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 10-92907 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] Furthermore, according to the method of Patent Document 1, the gap between adjacent semiconductor bare chips becomes larger as the side faces upward on the spherical adsorption surface of the carrier, so that adjacent semiconductors do not come into contact with each other and break or become defective. Figure 1 As described, the wafer sheet is deformed to bulge downward at the periphery of the stage, and the distance between adjacent semiconductor bare chips decreases as the side surfaces thereof face upward.

[0009] Meanwhile, in recent years, lasers have become increasingly used to cut semiconductor die. This approach significantly narrows the width of the semiconductor die, and the gaps between the sides of adjacent semiconductor dies also become extremely narrow. Consequently, if the wafer sheet deforms downwardly at the periphery of the stage, the gaps between the sides of adjacent semiconductor dies decrease as they move upward. This can lead to contact between the sides of adjacent semiconductor dies, resulting in cracks or defects.

[0010] Therefore, an object of the semiconductor bare die pickup device of the present invention is to suppress damage to the semiconductor bare die when the semiconductor bare die is picked up from a wafer sheet.

[0011] Technical means to solve the problem

[0012] The semiconductor bare chip pickup device of the present invention picks up the semiconductor bare chip attached to the upper surface of the wafer sheet. The semiconductor bare chip pickup device includes: a carrier, including a suction surface for sucking the lower surface of the wafer sheet and an opening provided on the suction surface; a carrier drive mechanism for driving the carrier in the vertical direction; and a moving element disposed in the opening of the carrier and moving in a manner such that the front end protrudes from the suction surface. The semiconductor bare chip pickup device includes: a moving element drive mechanism for driving the moving element in the vertical direction; a chuck for picking up the semiconductor bare chip; a vacuum device for setting the interior of the carrier to a vacuum; and The control unit adjusts the actions of the stage driving mechanism, the moving element driving mechanism, the chuck and the vacuum device. The adsorption surface is a curved surface that is convexly curved upward. The control unit uses the stage driving mechanism to raise the stage to push the wafer sheet upward. After pushing the wafer sheet upward, the vacuum device is used to set the interior of the stage to a vacuum so that the wafer sheet is adsorbed on the adsorption surface. After the wafer sheet is adsorbed on the adsorption surface, the moving element driving mechanism is used to protrude the moving element from the adsorption surface to push up the semiconductor bare chip to be picked up from the bottom of the wafer sheet, and the chuck is used to pick up the semiconductor bare chip from the wafer sheet.

[0013] By configuring the carrier's suction surface to be curved upwardly and convexly, the gap between the side faces of adjacent semiconductor die increases as they move upward on the carrier's suction surface, thereby preventing adjacent semiconductors from contacting each other and causing cracks or defects. Furthermore, by pushing the wafer sheet onto the carrier and then adsorbing it to the suction surface, the phenomenon in which the wafer sheet deforms downwardly and convexly at the periphery of the carrier when adsorbed to the suction surface, and the gap between the side faces of adjacent semiconductor die decreases as they move upward, is eliminated. Consequently, the phenomenon in which the side faces of adjacent semiconductor die contact each other at the periphery of the carrier and cause cracks or defects is prevented.

[0014] In the semiconductor bare chip picking device of the present invention, the carrier can also be cylindrical in shape and the adsorption surface can be a spherical crown surface. When the control unit pushes up the chip sheet, it causes the carrier to rise until the lower surface of the chip sheet contacts the corner of the cylindrical side of the carrier and the adsorption surface.

[0015] In this way, the carrier is raised until the lower surface of the chip sheet contacts the corner of the cylindrical side of the carrier and the adsorption surface. As a result, the chip sheet at the periphery of the carrier is deformed in an upward convex manner. The further the side surfaces of adjacent semiconductor bare chips face upward, the larger the distance between them becomes. This can prevent adjacent semiconductors from contacting each other and causing cracks or defects.

[0016] Moreover, in the semiconductor bare chip picking device of the present invention, the corner portion may include a curved surface connecting the side surface of the carrier and the adsorption surface, and the control unit may raise the carrier when pushing up the chip sheet until the height of the ridge line between the side surface of the carrier and the adsorption surface in the corner portion becomes greater than the height of the lower surface of the chip sheet in the side surface of the carrier.

[0017] In this way, the carrier is raised until the height of the side surface of the carrier and the ridge line of the adsorption surface in the corner becomes higher than the height of the lower surface of the chip sheet in the side surface of the carrier. Therefore, the chip sheet at the periphery of the carrier is deformed in an upward convex manner, and the spacing between adjacent semiconductor bare chips becomes larger as the side surfaces face upward, thereby preventing adjacent semiconductors from contacting each other and causing cracks or defects.

[0018] In the semiconductor bare chip picking device of the present invention, the carrier may be cylindrical in shape, the adsorption surface may be a spherical crown surface, the opening of the carrier may be arranged in the center of the adsorption surface, the adsorption surface may include an inner periphery around the opening and an outer periphery outside the inner periphery, the inner periphery includes an inner adsorption hole connected to the vacuum device, and the control unit may raise the carrier when pushing up the chip sheet until the lower surface of the chip sheet contacts the outer periphery end of the inner periphery of the carrier, and when adsorbing the chip sheet, the vacuum device may be used to set the inner adsorption hole to a vacuum so that the chip sheet is adsorbed on the inner periphery of the adsorption surface.

[0019] In this way, the carrier is raised until the outer peripheral end of the inner peripheral portion of the adsorption surface, which is a spherical crown surface, contacts the lower surface of the chip sheet, and the chip sheet is adsorbed on the inner peripheral portion. Therefore, when the chip sheet is adsorbed on the inner peripheral portion of the adsorption surface, the chip sheet can be prevented from convexly deforming downward at the outer peripheral portion of the adsorption surface, thereby preventing adjacent semiconductor bare chips from contacting and causing cracks or defects.

[0020] In the semiconductor bare chip picking device of the present invention, the carrier may further include outer adsorption holes connected to the vacuum device at the outer periphery. When the control unit pushes up the chip sheet, the carrier is raised until the lower surface of the chip sheet contacts the outer peripheral end of the outer periphery of the carrier. When the chip sheet is adsorbed, the inner adsorption holes and the outer adsorption holes are set to vacuum by the vacuum device so that the chip sheet is adsorbed to the inner periphery and the outer periphery of the adsorption surface.

[0021] In this way, the chip sheet is in close contact with the inner and outer peripheries of the adsorption surface of the carrier, thereby preventing the chip sheet from being deformed to convex downward at the outer periphery of the adsorption surface when the chip sheet is adsorbed on the inner and outer peripheries of the adsorption surface, thereby preventing the adjacent semiconductor bare chips from contacting and causing cracks or defects.

[0022] In the semiconductor bare chip picking device of the present invention, the control unit may also be such that, when picking up a semiconductor bare chip attached to the upper surface of the peripheral part of the wafer sheet, the control unit raises the carrier while pushing up the wafer sheet until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral part of the carrier, and when adsorbing the wafer sheet, the inner adsorption holes are set to vacuum by a vacuum device so that the wafer sheet is adsorbed to the inner peripheral part of the adsorption surface. When picking up a semiconductor bare chip attached to the upper surface of the central part of the wafer sheet, the control unit raises the carrier while pushing up the wafer sheet until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral part of the carrier, and when adsorbing the wafer sheet, the inner adsorption holes and the outer adsorption holes are set to vacuum by a vacuum device so that the wafer sheet is adsorbed to the inner peripheral part and the outer peripheral part of the adsorption surface.

[0023] Thus, when picking up a semiconductor bare die attached to the peripheral portion of the wafer sheet, it is possible to suppress chipping or cracking of the semiconductor bare die located at the peripheral edge of the stage.

[0024] In the semiconductor bare chip picking device of the present invention, the movable element may also include: a first lift pin, arranged at the center of the carrier; and a cylindrical second lift pin, arranged at the outer periphery of the first lift pin, and the movable element driving mechanism drives the first lift pin and the second lift pin in the vertical direction. When picking up the semiconductor bare chip, the control unit uses the movable element driving mechanism to cause the second lift pin to protrude from the adsorption surface, and then causes the first lift pin to protrude to a position higher than the front end of the second lift pin.

[0025] In this way, after the cylindrical second lift pins are raised to start peeling the outer periphery of the semiconductor die from the wafer sheet, the semiconductor die is further lifted by the first lift pins to be picked up from the wafer sheet. Therefore, the semiconductor die can be picked up from the wafer sheet without damaging it.

[0026] The semiconductor bare chip picking method of the present invention picks up the semiconductor bare chip attached to the upper surface of the wafer sheet, and the semiconductor bare chip picking method includes: a preparation step, preparing a picking up device, the picking up device including a suction surface for sucking the lower surface of the wafer sheet and a carrier with an opening provided on the suction surface, a moving element arranged in the opening of the carrier and moving in a manner that the front end protrudes from the suction surface, and a chuck for picking up the semiconductor bare chip, wherein the suction surface is a curved surface that is convexly curved upward; a pushing up step, causing the carrier to rise and push up the wafer sheet; an suction step, causing the wafer sheet to be sucked onto the suction surface after the pushing up step; and a picking up step, causing the moving element to protrude from the suction surface and push up the semiconductor bare chip to be picked up from the bottom of the wafer sheet after the suction step, and using the chuck to pick up the semiconductor bare chip.

[0027] In the semiconductor bare chip picking method of the present invention, the semiconductor bare chip picking device prepared in the preparation step may also have a cylindrical carrier and a spherical crown surface as the carrier, and the pushing step is to raise the carrier until the lower surface of the chip sheet contacts the corner of the cylindrical side surface of the carrier and the adsorption surface.

[0028] In the semiconductor bare chip picking method of the present invention, it can also be that in the semiconductor bare chip picking device prepared in the preparation step, the corner includes a curved surface connecting the side surface of the carrier and the adsorption surface, and the pushing-up step is to raise the carrier until the height of the side surface of the carrier and the ridge line of the adsorption surface in the corner becomes greater than the height of the lower surface of the chip sheet in the side surface of the carrier.

[0029] In the semiconductor bare chip picking method of the present invention, it can also be that in the semiconductor bare chip picking device prepared in the preparation step, the carrier is cylindrical in shape, the adsorption surface is a spherical crown surface, the opening of the carrier is arranged in the center of the adsorption surface, the adsorption surface includes an inner peripheral portion around the opening and an outer peripheral portion outside the inner peripheral portion, and the inner peripheral portion includes an inner adsorption hole. The pushing step is to raise the carrier until the lower surface of the chip sheet contacts the outer peripheral end of the inner peripheral portion of the carrier. The adsorption step is to set the inner adsorption hole to vacuum so that the chip sheet is adsorbed on the inner peripheral portion of the adsorption surface.

[0030] In the semiconductor bare chip picking method of the present invention, the semiconductor bare chip picking device prepared in the preparation step may further include outer adsorption holes in the outer periphery, and the pushing-up step is to raise the carrier until the lower surface of the chip sheet contacts the outer periphery of the carrier, and the adsorption step is to set the inner adsorption holes and the outer adsorption holes to vacuum so that the chip sheet is adsorbed on the inner periphery and the outer periphery of the adsorption surface.

[0031] In the method for picking up a semiconductor bare chip of the present invention, when picking up a semiconductor bare chip attached to the upper surface of the peripheral part of the wafer sheet, the pushing-up step is to raise the carrier until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral part of the carrier, and the adsorption step is to set the inner adsorption hole to vacuum so that the wafer sheet is adsorbed on the inner peripheral part of the adsorption surface. When picking up a semiconductor bare chip attached to the upper surface of the central part of the wafer sheet, the pushing-up step is to raise the carrier until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral part of the carrier, and the adsorption step is to set the inner adsorption hole and the outer adsorption hole to vacuum so that the wafer sheet is adsorbed on the inner peripheral part and the outer peripheral part of the adsorption surface.

[0032] In the semiconductor bare chip picking method of the present invention, it may also be that in the semiconductor bare chip picking device prepared in the preparation step, the movable element includes: a first lift pin, which is arranged at the center of the carrier; and a cylindrical second lift pin, which is arranged at the outer periphery of the first lift pin. The picking step is to make the second lift pin protrude from the adsorption surface, then make the first lift pin protrude to a position higher than the front end of the second lift pin, and use a chuck to pick up the semiconductor bare chip.

[0033] Effects of the Invention

[0034] The semiconductor bare die pickup device of the present invention can suppress damage to the semiconductor bare die when picking up the semiconductor bare die from a wafer sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a system diagram showing the configuration of a pickup device for semiconductor bare chips according to an embodiment.

[0036] Figure 2 yes Figure 1 A cross-sectional view of a carrier of a semiconductor bare die pickup device is shown.

[0037] Figure 3 yes Figure 2 Detailed cross-sectional view of section A shown.

[0038] Figure 4 It is an explanatory diagram showing the contact area between the lower surface of the wafer sheet and the suction surface of the stage when the height of the stage is changed.

[0039] Figure 5 yes Figure 1 The diagram illustrating the pickup operation of a semiconductor die by the semiconductor die pickup device is a cross-sectional view of the stage, wafer sheet, and semiconductor die when the stage is raised to a position (Z=0) where the top of the stage contacts the lower surface of the wafer sheet.

[0040] Figure 6 It means from Figure 5 The state shown makes the top of the platform rise to Figure 4 The cross-sectional view of the stage, wafer sheet, and semiconductor bare die at the time of Z1 shown.

[0041] Figure 7 It means from Figure 6 The state shown makes the top of the platform rise to Figure 4 The cross-sectional view of the stage, wafer sheet, and semiconductor bare die up to Z3 is shown.

[0042] Figure 8 yes Figure 7 Detailed cross-sectional view of section B shown.

[0043] Figure 9It means from Figure 7 The state shown is a cross-sectional view of the stage, the wafer sheet, and the semiconductor bare die when the interior of the stage is set to a vacuum and the wafer sheet is adsorbed onto the adsorption surface of the stage.

[0044] Figure 10 It means from Figure 9 The figure shows a cross-sectional view of the carrier, wafer sheet, semiconductor die, and chuck when the second lift pin is protruding from the suction surface.

[0045] Figure 11 It means from Figure 10 The state shown is a cross-sectional view of the carrier, wafer sheet, semiconductor die, and chuck when the front end of the first lift pin is raised above the front end of the second lift pin to lift the semiconductor die upward.

[0046] Figure 12 This is an explanatory diagram showing the positional relationship and dimensions of the stage and wafer sheet when the stage is raised to a height Z2.

[0047] Figure 13 This is a diagram showing a cross section of a stage of a semiconductor bare die pickup device according to another embodiment and a system of a vacuum device connected to the stage.

[0048] Figure 14 yes Figure 13 The illustration of the first picking-up operation of the semiconductor bare die by the semiconductor bare die picking-up device shown in FIG. 1 shows the process of raising the top of the carrier to the position of the semiconductor bare die. Figure 4 The cross-sectional view of the stage, wafer sheet, and semiconductor bare die at the time of Z1 shown.

[0049] Figure 15 It means from Figure 14 The state shown is a cross-sectional view of a state in which the inner suction holes are set to a vacuum and the wafer sheet is sucked onto the inner peripheral portion of the suction surface.

[0050] Figure 16 It means from Figure 15 The figure shows a cross-sectional view of the carrier, wafer sheet, semiconductor die, and chuck when the second lift pin is protruding from the suction surface.

[0051] Figure 17 It means from Figure 16 The state shown is a cross-sectional view of the carrier, wafer sheet, semiconductor die, and chuck when the front end of the first lift pin is raised above the front end of the second lift pin to lift the semiconductor die upward.

[0052] Figure 18 yes Figure 13 The illustration of the second picking-up operation of the semiconductor bare die by the semiconductor bare die picking-up device shown in FIG. 1 shows the process of raising the top of the carrier to the position of the semiconductor bare die. Figure 4The cross-sectional view of the stage, wafer sheet, and semiconductor bare die up to Z2 is shown.

[0053] Figure 19 It means from Figure 18 The figure shows a cross-sectional view of a wafer sheet, a semiconductor die, and a chuck in a state where the inner and outer suction holes are set to vacuum and the wafer sheet is sucked onto the inner and outer peripheries of the suction surface.

[0054] Figure 20 This is an explanatory diagram showing the positional relationship and dimensions between the stage and the wafer sheet when the stage is positioned offset to one side from the center of the wafer ring and the stage is raised to a height Z4.

[0055] Figure 21 It shows that in the semiconductor bare chip pickup device of the comparative example, the height Z of the stage before the stage is raised is Figure 4 In the state shown in FIG0 , a cross-sectional view of the stage, the wafer sheet, and the bare semiconductor die is shown when the interior of the stage is set to a vacuum and the lower surface of the wafer sheet is adsorbed onto the adsorption surface.

[0056] [Explanation of Symbols]

[0057] 10: Chip holder

[0058] 11: Chip

[0059] 12: Wafer sheet

[0060] 12a: Upper surface

[0061] 12b: Lower surface

[0062] 12e: Height

[0063] 12f: Fixed loop line

[0064] 13: Ring

[0065] 14: Gap

[0066] 15, 151-155: semiconductor die

[0067] 16: Expansion Ring

[0068] 16a: Keeping face

[0069] 16b: flange

[0070] 17: Ring press

[0071] 18: Chuck

[0072] 19: Suction hole

[0073] 20, 120: carrier

[0074] 21, 121: cylindrical part

[0075] 21a, 121a: Side

[0076] 21c, 121c: Center

[0077] 22, 122: Upper end plate

[0078] 22a, 122a: Adsorption surface

[0079] 22b, 122b: Vertex

[0080] 22c, 25c, 122c, 122d, 125c: Loop lines

[0081] 22t: cut surface

[0082] 23, 123: Open

[0083] 24, 124: adsorption holes

[0084] 25, 125: Corner

[0085] 25a, 25b, 125a, 125b: connecting wires

[0086] 25s, 125s: Ridge

[0087] 29: Moving element drive mechanism

[0088] 30: Moving components

[0089] 31: First ejector pin

[0090] 32: Second ejector pin

[0091] 61: Wafer holder horizontal drive unit

[0092] 62: Carrier up and down direction drive unit

[0093] 63: Chuck drive unit

[0094] 64, 65, 66: Vacuum valve

[0095] 68: Vacuum device

[0096] 70: Control Department

[0097] 71: CPU

[0098] 72: Memory

[0099] 80: Arrow

[0100] 100, 110, 300: Pickup device

[0101] 122e: Inner circumference

[0102] 122f: Peripheral part

[0103] 124a: Inner adsorption hole

[0104] 124b: outer adsorption hole

[0105] 126: Outer cavity

[0106] 127: Partition wall

[0107] D: diameter of the fixed ring line

[0108] d: diameter of the carrier

[0109] L5, L6: distance

[0110] R1, R2: radius

[0111] W0~W3:width

[0112] Z, Z1~Z4: height

[0113] θ1~θ3, θ5, θ6, θc: angle

[0114] θi, θr: center angle DETAILED DESCRIPTION

[0115] Hereinafter, a semiconductor bare die pickup device 100 according to an embodiment will be described with reference to the drawings.

[0116] like Figure 1 As shown, the semiconductor bare chip picking device 100 (hereinafter referred to as the picking device 100) of the embodiment includes: a chip holder 10, a carrier 20, a chuck 18, a chip holder horizontal direction driving unit 61, a carrier up and down direction driving unit 62, a chuck driving unit 63, a vacuum valve 64, a vacuum valve 65, a vacuum device (VAC) 68 and a control unit 70.

[0117] The wafer holder 10 includes an annular expander ring 16 with a flange and a ring retainer 17, and holds the wafer sheet 12 having semiconductor die 15 cut from the wafer 11 attached to its upper surface 12a. The wafer holder 10 is moved horizontally by a wafer holder horizontal drive unit 61.

[0118] Here, a wafer sheet 12 with semiconductor die 15 attached to its upper surface 12a is held by a wafer holder 10 as follows. Wafer 11 has wafer sheet 12 attached to its back surface, and a metal ring 13 is attached to the outer periphery of wafer sheet 12. During a cutting step, wafer 11 is cut from the front side using a dicing saw or the like to form individual semiconductor die 15. Gaps 14 are created between the semiconductor die 15 during the cutting process. Even when wafer 11 is cut, wafer sheet 12 remains intact, and individual semiconductor die 15 are held by wafer sheet 12.

[0119] The lower surface 12b of the wafer sheet 12 with the semiconductor die 15 attached to the upper surface 12a is placed in contact with the holding surface 16a of the expansion ring 16, and the position of the ring 13 is adjusted so that it is on the flange 16b of the expansion ring 16. Figure 1 As shown by arrow 80 in FIG. 1 , ring 13 is pressed from above onto flange 16b of expansion ring 16 by ring retainer 17, securing it to flange 16b. As a result, wafer sheet 12, with semiconductor die 15 attached to upper surface 12a, is held in wafer holder 10. At this point, lower surface 12b of wafer sheet 12 is secured to the outer peripheral edge of retaining surface 16a of expansion ring 16.

[0120] The stage 20 is arranged on the lower surface of the wafer holder 10. The stage 20 includes a cylindrical portion 21 and an upper end plate 22, which is a cover on the upper side of the cylindrical portion 21. The surface of the upper end plate 22 is a suction surface 22a that suctions the lower surface 12b of the wafer sheet 12. An opening 23 for the entry and exit of the movable element 30 is provided in the center of the upper end plate 22, and suction holes 24 for suctioning the lower surface 12b of the wafer sheet 12 are provided around the opening 23. Inside the cylindrical portion 21, there are provided the movable element 30 and a movable element driving mechanism 29 that drives the movable element 30. The movable element 30 includes a first lift pin 31 arranged at the center of the stage 20 and a cylindrical second lift pin 32 arranged on the outer periphery of the first lift pin 31. The moving element driving mechanism 29 includes a driving motor, gears, a coupling mechanism, etc., and drives the first and second lift pins 31 and 32 in the vertical direction so that they protrude from the adsorption surface 22a through the opening 23. The carrier 20 is moved in the vertical direction as a whole by the carrier vertical direction driving unit 62. In addition, the interior of the carrier 20 is connected to the vacuum device 68 via the vacuum valve 64. For details about the carrier 20, please refer to Figure 2 、 Figure 3 While explaining.

[0121] The chuck 18 is positioned above the wafer sheet 12, suction-holding the semiconductor die 15 on its lower surface and picking up the semiconductor die 15 from the upper surface 12a of the wafer sheet 12. The chuck 18 is provided with suction holes 19 for vacuum-sucking the semiconductor die 15 to its lower surface. The suction holes 19 are connected to a vacuum device 68 via a vacuum valve 65. The chuck 18 is moved in the vertical and horizontal directions by a chuck drive 63.

[0122] The wafer holder horizontal drive unit 61, the stage vertical drive unit 62, the chuck drive unit 63, the vacuum valve 64, the vacuum valve 65, the vacuum device 68, and the moving element drive mechanism 29 are connected to a control unit 70 and operate according to instructions from the control unit 70. The control unit 70 is a computer that internally includes a central processing unit (CPU) 71, which performs information processing, and a memory 72 for storing programs and the like.

[0123] Next, refer to Figure 2 、 Figure 3 , while explaining the structure of the carrier 20. As mentioned above, the carrier 20 includes a cylindrical portion 21 and a cover on the upper side of the cylindrical portion 21, that is, an upper end plate 22. The surface of the upper end plate 22 is a curved surface that is convexly curved upward, and constitutes an adsorption surface 22a that adsorbs the lower surface 12b of the wafer sheet 12. Figure 2 As shown, the suction surface 22a is a spherical crown surface with a radius R1 and a central angle θr. The suction surface 22a is connected to the side surface 21a of the cylindrical portion 21 by a curved surface. The curved surface is a toroidal surface with a circular arc cross-section of radius R2 and angle θc, forming a corner 25 connecting the suction surface 22a and the side surface 21a. Here, radius R2 is smaller than radius R1, for example, approximately 0.1 mm to 0.5 mm relative to R = 600 mm.

[0124] The outer peripheral end of the suction surface 22a and the inner peripheral end of the corner 25 are connected by a circular connecting line 25a in such a way that the tangent direction of the outer peripheral end of the suction surface 22a becomes the tangent direction of the inner peripheral end of the corner 25. Moreover, the outer peripheral end of the corner 25 and the side surface of the cylindrical portion 21 are connected by a circular connecting line 25b in such a way that the outer peripheral end of the corner 25 becomes the direction perpendicular to the side surface 21a. Moreover, the vertex of the suction surface 22a is represented by the vertex 22b. Furthermore, Figure 2 The circular line 22 c shown is a circular line on the suction surface 22 a located between the connecting line 25 a and the vertex 22 b.

[0125] like Figure 3As shown, the surface extending radially outward from the connecting line 25a of the spherical cap surface 22a is a cut surface 22t tangential to the suction surface 22a on the connecting line 25a. Furthermore, the intersection of this cut surface 22t and the circular shape of the side surface 21a of the cylindrical portion 21 forms an edge line 25s between the suction surface 22a and the side surface 21a in the corner portion 25. Thus, the edge line 25s is the intersection of the cut surface 22t of the suction surface 22a on the connecting line 25a and the side surface 21a.

[0126] return Figure 2 In the center of the upper end plate 22, a circular opening 23 is provided that passes through the upper end plate 22. The moving element 30 including the first upper ejector pin 31 and the second upper ejector pin 32 moves in the vertical direction in the opening 23 so that the front end protrudes from the adsorption surface 22a. In addition, a plurality of adsorption holes 24 are provided on the outer peripheral side of the opening 23 to connect the adsorption surface 22a with the interior of the carrier 20. Figure 1 As shown, the interior of the stage 20 is connected to a vacuum device 68 via a vacuum valve 64. When the vacuum valve 64 is opened, the opening 23 and the suction hole 24 are vacuumed together with the interior of the stage 20 by the vacuum device 68, thereby vacuum-sucking the lower surface 12b of the wafer sheet 12 to the suction surface 22a.

[0127] Next, refer to Figures 4 to 11 , while describing the operation of picking up the semiconductor die 15 by the pickup device 100. In the following description, it is assumed that the wafer sheet 12 is held horizontally on the holding surface 16a of the expansion ring 16 of the wafer holder 10 at a position where the height Z of the lower surface 12b is 0. Figure 4 The fixed circular line 12f shown is a line indicating the outer peripheral end of the holding surface 16a of the expansion ring 16 with which the lower surface 12b of the wafer sheet 12 contacts, and is a line indicating the position where the wafer sheet 12 is fixed to the holding surface 16a of the expansion ring 16. Figure 5 As shown, a plurality of semiconductor bare dies 151 to 155 are attached to the upper surface 12 a of the wafer sheet 12 , and the pickup device 100 will be described as picking up the semiconductor bare die 151 at the center.

[0128] like Figure 4 The graph of Z=0 and Figure 5 As shown, the processor of the control unit 70, i.e., the CPU 71, drives the wafer holder horizontal direction driving unit 61 to drive the wafer holder 10 in the horizontal direction and adjusts the horizontal position of the wafer holder 10 so that the semiconductor bare die 151 to be picked up is at the center 21c of the cylindrical portion 21 of the carrier 20. Then, the CPU 71 of the control unit 70 drives the carrier vertical direction driving unit 62 to adjust the height Z of the vertex 22b of the suction surface 22a of the carrier 20 to a position of 0. As a result, as shown in FIG. Figure 5As shown, the center of the semiconductor bare die 151 is located at the center 21 c of the stage 20 , and the vertex 22 b of the suction surface 22 a is in contact with the lower surface 12 b of the wafer sheet 12 .

[0129] Because the suction surface 22a is a spherical crown, in this state, only the vertex 22b contacts the lower surface 12b of the wafer sheet 12. Furthermore, in this state, the vacuum valve 64 is closed, and the interior of the stage 20 is at atmospheric pressure, so the wafer sheet 12 is not suctioned to the suction surface 22a. Therefore, a gap exists between the suction surface 22a of the stage 20 and the lower surface 12b of the wafer sheet 12 in the area other than the vertex 22b.

[0130] Furthermore, the wafer sheet 12 is in a horizontally extended state, and the gaps between the upper ends of the side surfaces of the semiconductor bare dies 151 to 155 attached to the upper surface 12 a of the wafer sheet 12 are all W0.

[0131] like Figure 4 The graph of Z=Z1 and Figure 6 As shown, the CPU 71 of the control unit 70 drives the stage up-down direction driving unit 62 to raise the vertex 22b of the adsorption surface 22a of the stage 20 to a height Z1 and push up the wafer sheet 12 (pushing up step). Figure 4 As shown by the thick solid line in the figure with Z = Z1, the lower surface 12b of the wafer sheet 12 contacts the suction surface 22a, which is located on the center side of the circular line 22c. At this time, the lower surface 12b of the wafer sheet 12 extends in the direction tangent to the suction surface 22a within the circular line 22c, and is inclined at an angle θ1 from the surface at a height Z of 0. The area of the suction surface 22a surrounded by the circular line 22c forms an upwardly convex spherical crown with a radius R1 and a central angle of 2×θ1.

[0132] The wafer sheet 12 on the inner circumference side of the circular line 22c is deformed to convexly face upward along the spherical crown surface of the adsorption surface 22a. Therefore, the gap between the side surfaces of the semiconductor die 151 located at the center and the adjacent semiconductor die 152 becomes larger as it goes upward, and the gap between the upper ends of the side surfaces of the semiconductor die 151 and the semiconductor die 152 expands to more than 1 / 4 of the gap. Figure 5 Similarly, the gap between the upper ends of the side surfaces of the semiconductor die 151 and the semiconductor die 153 also extends to W1.

[0133] In this state, the vacuum valve 64 is closed, the interior of the stage 20 is at atmospheric pressure, and the wafer sheet 12 is not adsorbed on the adsorption surface 22a. Therefore, a gap is left between the adsorption surface 22a on the outer side of the circular line 22c and the lower surface 12b of the wafer sheet 12. Therefore, the wafer sheet 12 on the outer side of the circular line 22c extends straight toward the tangent direction of the adsorption surface 22a in the circular line 22c, so that the semiconductor die 152 attached thereto is parallel to the side surface of the adjacent semiconductor die 154, and the gap at the upper end of the side surface is still maintained. Figure 5 Similarly, the gap between the upper end of the side surface of the semiconductor die 153 and the adjacent semiconductor die 155 is also maintained at Figure 5 W0 described in .

[0134] like Figure 4 As shown in the figure where Z=Z2, the CPU 71 of the control unit 70 drives the stage vertical direction driving unit 62 to raise the height Z of the vertex 22b of the adsorption surface 22a of the stage 20 to Z2, thereby further pushing up the wafer sheet 12. Figure 4 As shown by the thick solid line in the figure where Z = Z2, the lower surface 12b of the wafer sheet 12 contacts the suction surface 22a, extending from the vertex 22b to the connecting line 25a between the suction surface 22a and the corner 25. At this point, the lower surface 12b of the wafer sheet 12 extends in the direction tangent to the suction surface 22a on the connecting line 25a, tilted at an angle θ2 from the plane at a height Z of 0. The area of the suction surface 22a enclosed by the connecting line 25a forms an upwardly convex spherical crown with a radius R1 and a central angle of 2×θ2.

[0135] In this state, a gap is left between the corner portion 25 on the outer peripheral side of the connecting line 25a and the lower surface 12b of the wafer sheet 12. In addition, at this time, the height of the ridge line 25s is the same as the height of the lower surface 12b of the wafer sheet 12 at the position of the side surface 21a of the cylindrical portion 21.

[0136] Furthermore, if Figure 4 The graph of Z=Z3 and Figure 7 As shown, the CPU 71 of the control unit 70 drives the stage vertical direction driving unit 62 to raise the height Z of the vertex 22b of the adsorption surface 22a of the stage 20 to Z3, thereby further pushing up the wafer sheet 12. Figure 4As shown by the thick solid line in the figure with Z = Z3, the lower surface 12b of the wafer sheet 12 contacts the area from the vertex 22b to the circular line 25c in the corner 25. At this time, the lower surface 12b of the wafer sheet 12 extends in the direction tangent to the circular line 25c in the corner 25, and is inclined at an angle θ3 from the surface at a height Z of 0. The area surrounded by the circular line 25c forms an upwardly convex curved surface extending from the suction surface 22a to the curved surface of the corner 25.

[0137] The wafer sheet 12 located on the center side of the stage 20 relative to the circular line 25c is deformed to convexly move upward along the upwardly convex curved surface following the curved surface of the suction surface 22a and the corner portion 25, so that Figure 7 As shown, the gap between the side surfaces of the semiconductor die 152 attached thereto and the adjacent semiconductor die 154 becomes larger as it goes upwards, and the gap between the upper ends of the side surfaces of the semiconductor die 152 and the semiconductor die 154 expands to be larger than Figure 5 Similarly, the gap between the upper ends of the side surfaces of the semiconductor bare chip 153 and the semiconductor bare chip 155 is also expanded to W2.

[0138] When the apex 22b of the stage 20 is raised to a height Z3, the lower surface 12b of the wafer sheet 12 contacts a portion of the curved surface of the outer edge of the suction surface 22a, namely, the corner 25 outside the connecting line 25a. The radius R2 of this portion is smaller than the radius R1 of the suction surface 22a. Therefore, the curvature radius of the wafer sheet 12 near the circular line 25c becomes smaller than the curvature radius of the wafer sheet 12 curved along the suction surface 22a. Consequently, the expansion angle of the gap between the side surfaces of the semiconductor die 152 and the adjacent semiconductor die 154 becomes larger than the expansion angle of the gap between the side surfaces of the semiconductor die 151 and the semiconductor die 152. Consequently, the gap W2 becomes wider than the gap W1.

[0139] In this state, the vacuum valve 64 is closed, the interior of the stage 20 is at atmospheric pressure, and the wafer sheet 12 is not adsorbed on the adsorption surface 22a. Therefore, a gap is left between the corner portion 25 on the outer peripheral side of the circular line 25c and the lower surface 12b of the wafer sheet 12. Figure 8 As shown, at this time, the height of the ridge line 25 s becomes higher than the height 12 e of the lower surface 12 b of the wafer sheet 12 at the position of the side surface 21 a of the cylindrical portion 21 .

[0140] Next, the CPU 71 of the control unit 70 opens the vacuum valve 64 to evacuate the interior of the stage 20. This evacuates the opening 23 and the plurality of suction holes 24, and vacuum-suctions the lower surface 12b of the wafer sheet 12 onto the suction surface 22a (suction step).

[0141] When the top 22b of the stage 20 is raised to the height Z3, as shown in FIG. Figure 7 As described above, the wafer sheet 12 is deformed in an upward convex manner along the spherical crown surface of the suction surface 22a and the curved surface of the corner 25, and the lower surface 12b contacts the spherical crown surface of the suction surface 22a and the curved surface of the corner 25. Therefore, when the interior of the stage 20 is set to a vacuum and the lower surface 12b of the wafer sheet 12 is vacuum-adsorbed on the suction surface 22a, the wafer sheet 12 remains in the same upward convex deformed state as before the vacuum adsorption. Therefore, even if the lower surface 12b of the wafer sheet 12 is vacuum-adsorbed on the suction surface 22a, the gap between the upper ends of the semiconductor bare chips 151 to 155 is maintained at the reference position. Figure 7 The state described is that W1 and W2 are wider than the initial W0.

[0142] Next, the CPU 71 of the control unit 70 moves the chuck 18 to the semiconductor die 151 through the chuck driving unit 63, opens the vacuum valve 65, and sets the suction hole 19 of the chuck 18 to a vacuum state, so that the chuck 18 is vacuum-adsorbed onto the semiconductor die 151. Then, the CPU 71 of the control unit 70 drives the moving element driving mechanism 29, so that Figure 10 As shown, the first and second lift pins 31 and 32 are moved upward together so that their respective tips protrude from the suction surface 22 a and lift the semiconductor die 151 . The chuck 18 is lifted in conjunction with the lifting of the first and second lift pins 31 and 32 .

[0143] As a result, the start of separation between the wafer sheet 12 and the semiconductor bare die 151 is generated at the periphery of the semiconductor bare die 151. At this time, a small separation may also be generated at the periphery of the semiconductor bare die 151.

[0144] Next, the CPU 71 of the control unit 70 Figure 11 As shown, the first lift pins 31 are further raised to lift the semiconductor die 151 , and the chuck 18 is raised in conjunction with the raising of the first lift pins 31 , so that the semiconductor die 151 is picked up by the chuck 18 (picking up step).

[0145] As described above, in the pickup device 100 of the embodiment, the adsorption surface 22a of the stage 20 is set as a spherical crown surface convex upward, so Figures 5 to 7 As shown, as the stage 20 is raised, the wafer sheet 12 is deformed to convexly face upward along the spherical crown surface of the adsorption surface 22a or the curved surface of the corner 25. Figure 7 、 Figure 8 As shown, when the height Z of the stage 20 is raised to Z3 , the gaps between the upper ends of the side surfaces of the semiconductor bare chips 151 to 155 are expanded to W1 and W2 , which are wider than the initial W0 .

[0146] When the stage 20 is raised to height Z3, the wafer sheet 12 deforms upwardly convexly along the spherical crown of the suction surface 22a and the curved surface of the corner 25, with the lower surface 12b contacting the spherical crown of the suction surface 22a and the curved surface of the corner 25. Therefore, when the interior of the stage 20 is evacuated and the lower surface 12b of the wafer sheet 12 is vacuum-attached to the suction surface 22a, the wafer sheet 12 remains in this convexly deformed state, and the gaps between the upper ends of the semiconductor die 151-155 are maintained at W1 and W2, which are wider than the initial W0. This prevents the upper ends of the side surfaces of adjacent semiconductor die 151-155 from contacting each other during pickup, leading to damage or cracking.

[0147] In contrast, Figure 21 As shown in the comparative example pickup device 300, before the stage 20 is raised, when the wafer sheet 12 is vacuum-adsorbed in a state where the height Z of the vertex 22b of the adsorption surface 22a is zero, the wafer sheet 12 is deformed upward along the upwardly convex spherical crown surface on the adsorption surface 22a. At this time, the lower surface 12b of the wafer sheet 12 is deformed downward from the height Z of zero. Figure 4 As described above, the wafer sheet 12 is fixed to the expansion ring 16 at the fixed circular line 12f with a height Z of 0. Therefore, the adsorption holes 24 on the outer peripheral side that is less subjected to vacuum adsorption are on the outer side, and the wafer sheet 12 extends upward toward the fixed circular line 12f with a height Z of 0. Therefore, at the periphery of the carrier 20, the wafer sheet 12 is bent and deformed convexly downward. In addition, the side surfaces of the semiconductor bare chip 153 and the adjacent semiconductor bare chip 155 attached to the wafer sheet 12 that is bent and deformed convexly downward become narrower as they go upward, and the width of the gap at the upper end of the side surface is reduced from 0. Figure 5 The initial width W0 shown is reduced to W4 which is narrower than W0. Figure 21 In the illustrated semiconductor die pickup device 300, when picking up semiconductor die 151 through 155, semiconductor die 153 located at the periphery of stage 20 may come into contact with the upper ends of the side surfaces of adjacent semiconductor die 155, causing chipping or cracking. In particular, when the initial width W0 is narrow, the likelihood of chipping or cracking semiconductor die 153 or 155 increases.

[0148] In contrast, in the pickup device 100 of the embodiment, as previously described, after the stage 20 is raised until the lower surface 12b of the wafer sheet 12 contacts the spherical crown of the suction surface 22a and the curved surface of the corner 25, the wafer sheet 12 is vacuum-sucked onto the suction surface 22a. This maintains the wafer sheet 12 in an upwardly convexly deformed state, preventing the wafer sheet 12 from deforming downwardly convexly. Consequently, the gaps between the upper ends of the semiconductor die 151-155 are maintained at W1 and W2, which are wider than the initial W0. This prevents the upper ends of the side surfaces of adjacent semiconductor die 151-155 from contacting each other during the pickup operation, thereby preventing them from being damaged or cracked.

[0149] In the above description, the control unit 70 raises the vertex 22b of the carrier 20 to a height of Z3, but is not limited to this. The height only needs to be above Z2. For example, after raising the vertex 22b of the carrier 20 to a height of Z2, the chip sheet 12 may be vacuum adsorbed onto the adsorption surface 22a.

[0150] At this time, the wafer sheet 12 does not cover the curved surface of the corner portion 25. Therefore, the expansion angle of the gap between the side surfaces of the semiconductor die 153 and the adjacent semiconductor die 155 is smaller than when the stage 20 is raised to height Z3. The gap between the upper ends of the side surfaces of the semiconductor die 151 and the semiconductor die 152 becomes W3, which is wider than W0 and narrower than W2. This will be explained in detail in the description of other embodiments below.

[0151] The structure of the pickup device 100 and the pickup operation of the semiconductor die 151 according to the embodiment have been described above. Figure 12 , while briefly explaining a design example of the carrier 20 of the pickup device 100.

[0152] Figure 12 and Figure 4 Similarly, the diagram of Z=Z2 shows a state in which the apex 22b of the suction surface 22a of the stage 20 is raised to the height Z2. Figure 12 In FIG. 1 , the diameter of the stage 20 is denoted as d, and the diameter of the fixed circular ring line 12 f of the expansion ring 16 that fixes the wafer sheet 12 is denoted as D.

[0153] The lower surface 12b of the wafer sheet 12 extends obliquely upward at an angle θ2 relative to the horizontal line at a height Z of 0, and contacts the outer peripheral end of the adsorption surface 22a, that is, the connecting line 25a. The diameter D of the fixed circular line 12f is 300mm, and the diameter d of the stage 20 is 8mm. D is larger than d, so

[0154] tan(θ2)≒2×Z2 / D…(1).

[0155] According to formula (1), the angle θ2 is

[0156] θ2=tan -1 (2×Z2 / D)…(2).

[0157] Furthermore, the R2 of the corner 25 is about 0.1 mm to 0.5 mm, which is very small relative to the diameter d of the stage 20.

[0158] sin(θ2)≒(d / 2) / R≒θ2…(3).

[0159] According to formula (1) and formula (3),

[0160] d / (2×R)=tan -1 (2×Z2 / D)…(4)

[0161] R=d / 2×tan -1 (2×Z2 / D)…(5).

[0162] Here, if Z2=1mm, D=300mm, d=8mm, then R≒600mm.

[0163] That is, in the case of a stage 20 with a diameter of 8 mm, if the radius R1 of the spherical crown of the suction surface 22 a is set to 600 mm, the stage 20 only needs to be raised by 1 mm and then the interior of the stage 20 is set to a vacuum to suction the wafer sheet 12 .

[0164] Regardless of the design examples described above, the radius R1 and the amount of lift of the stage 20 can be freely set in the pickup apparatus for each semiconductor bare die.

[0165] Next, refer to Figure 13 The structure of another embodiment of a semiconductor die pickup device 110 (hereinafter referred to as the pickup device 110) is described. Figure 1 The same parts as those of the pickup device 100 described above are denoted by the same reference numerals and their description will be omitted.

[0166] like Figure 13 As shown, in the pickup device 110, the structure of the carrier 120 is the same as that of the previous reference Figure 1 、 Figure 2 The pickup device 100 described here has the same structure as the pickup device 100 described above except that the structure of the stage 20 is different.

[0167] The carrier 120 includes an inner peripheral portion 122e around an opening 123 with an adsorption surface 122a at the center, and an outer peripheral portion 122f outside the inner peripheral portion 122e. The inner peripheral portion 122e is provided with inner adsorption holes 124a, and the outer peripheral portion 122f is provided with outer adsorption holes 124b. Figure 2The stage 20 described above is also a spherical crown surface with a radius of R1 and a central angle of θr. The suction surface 122a is connected to the side surface 121a of the cylindrical portion 121 via a corner 125 including a curved surface with a radius of R2 and an angle of θc.

[0168] The outer circumferential end of suction surface 122a and the inner circumferential end of corner portion 125 are connected by an annular connecting line 125a, such that the tangent direction of the outer circumferential end of suction surface 122a is tangent to the inner circumferential end of corner portion 125. Connecting line 125a is also an annular line 122d indicating the outer circumferential end of suction surface 122a. Furthermore, the outer circumferential end of corner portion 125 and the side surface of cylindrical portion 121 are connected by an annular connecting line 125b.

[0169] Here, inner circumference 122e is the area of suction surface 122a within circular line 122c between inner suction hole 124a and outer suction hole 124b, and is a spherical crown with a radius R1 and a central angle θi. Circular line 122c defines the outer circumference of inner circumference 122e. Similar to circular line 22c of stage 20, circular line 122c is positioned such that, when vertex 122b is raised to height Z1, the tangent direction of suction surface 122a on circular line 122c corresponds to the direction in which the lower surface 12b of wafer sheet 12 extends.

[0170] The outer peripheral portion 122f extends from the outer peripheral end of the inner peripheral portion 122e, namely the circular line 122c, to the outer peripheral end of the adsorption surface 122a, namely the circular line 122d or the connecting line 125a. The outer peripheral portion 122f is a spherical surface having a radius R1 and an angle θo.

[0171] The inner suction hole 124 a communicates with the inside of the cylindrical portion 121 of the stage 120 , and when the vacuum valve 64 attached to the pipe connected to the cylindrical portion 121 is opened, the inner suction hole 124 a is evacuated along with the opening 123 through the vacuum device 68 .

[0172] The outer suction holes 124b are connected to the outer cavity 126, which is surrounded by a partition wall 127 provided inside the cylindrical portion 121 of the stage 120. When the vacuum valve 66, which is installed in the piping connected to the outer cavity 126, is opened, the outer suction holes 124b are evacuated by the vacuum device 68. The outer cavity 126 is not connected to the opening 123 or the inner suction holes 124a. Therefore, by opening and closing the vacuum valves 64 and 66, the inner suction holes 124a and the outer suction holes 124b can be independently switched between a vacuum state and an atmospheric pressure state.

[0173] Here, the vacuum valve 66 , like the vacuum valve 64 , is connected to the control unit 70 and operates according to a command from the control unit 70 .

[0174] Next, refer to Figures 14 to 17 The first pickup operation of the pickup device 110 will now be described. The first pickup operation is an operation in which, after a step of pushing up the wafer sheet 12 by raising the vertex 122b of the stage 120 to a height Z1, the inner suction holes 124a of the stage 120 are set to a vacuum state to suction the lower surface 12b of the wafer sheet 12 to the inner peripheral portion 122e of the suction surface 122a (the suction step), and then the semiconductor bare die 151 is picked up.

[0175] like Figure 14 As shown, the CPU 71 of the control unit 70 drives the stage vertical direction driving unit 62 to raise the apex 122 b of the stage 120 to a height Z1 to push up the wafer sheet 12 .

[0176] As described above, the circular line 122c is arranged at the following position, that is, when the vertex 122b is raised to the height Z1, the tangent direction of the adsorption surface 122a on the circular line 122c becomes the position in which the lower surface 12b of the wafer sheet 12 extends. Therefore, when the vertex 122b is raised to the height Z1, the reference Figure 6 As described above, the lower surface 12b of the wafer sheet 12 contacts the inner circumference 122e of the adsorption surface 122a on the center side of the circular line 122c. At this time, the lower surface 12b of the wafer sheet 12 extends in the tangent direction of the adsorption surface 122a on the circular line 122c. The wafer sheet 12 is deformed to convexly upward along the inner circumference 122e of the adsorption surface 122a. Therefore, the gap between the side surface of the semiconductor bare chip 151 located at the center and the adjacent semiconductor bare chip 152 becomes larger as it moves upward, and the gap between the upper ends of the side surfaces of the semiconductor bare chip 151 and the semiconductor bare chip 152 expands to be larger than 1.5mm. Figure 5 Similarly, the gap between the upper ends of the side surfaces of the semiconductor die 151 and the semiconductor die 153 is also expanded to W1.

[0177] In this state, the vacuum valves 64 and 66 are closed, and the inner and outer cavities 126 of the carrier 120 are at atmospheric pressure, the inner adsorption holes 124a and the outer adsorption holes 124b are at atmospheric pressure, and the chip sheet 12 is not adsorbed on the inner peripheral portion 122e and the outer peripheral portion 122f. Therefore, there is a gap between the outer peripheral portion 122f, which is the outer periphery of the circular line 122c, and the lower surface 12b of the chip sheet 12. Moreover, the chip sheet 12 on the upper side of the outer peripheral portion 122f, which is the outer periphery of the circular line 122c, extends linearly toward the tangent direction of the circular line 122c, so that the semiconductor bare chip 152 attached to the upper surface 12a of the chip sheet 12 located on the upper side of the outer peripheral portion 122f is parallel to the side of the adjacent semiconductor bare chip 154, and the gap at the upper end of the side is still maintained. Figure 5Similarly, the gap between the upper end of the side surface of the semiconductor die 153 and the adjacent semiconductor die 155 is also maintained. Figure 5 W0 described in .

[0178] Next, the CPU 71 of the control unit 70 opens the vacuum valve 64. Figure 15 As shown, the opening 123 and the inner suction holes 124a are vacuumed, and the lower surface 12b of the wafer sheet 12 is vacuum-sucked to the inner periphery 122e of the suction surface 122a. Because the lower surface 12b of the wafer sheet 12 contacts the inner periphery 122e, the portion of the wafer sheet 12 above the inner periphery 122e remains convex upward even during vacuum suction. The gaps between the upper ends of the side surfaces of the semiconductor die 151 and semiconductor die 152, and between the upper ends of the side surfaces of the semiconductor die 151 and semiconductor die 153, are maintained at W1.

[0179] Meanwhile, the CPU 71 of the control unit 70 keeps the vacuum valve 66 closed, so the outer cavity 126 and the outer suction holes 124b are not vacuumed but remain at atmospheric pressure. Consequently, the wafer sheet 12 above the outer peripheral portion 122f continues to extend straight in the direction tangential to the circular line 12c, and the gap between the upper ends of the side surfaces of the semiconductor die 152 and the adjacent semiconductor die 154, and the gap between the upper ends of the side surfaces of the semiconductor die 153 and the adjacent semiconductor die 155, are maintained at W0.

[0180] Next, the CPU 71 of the control unit 70 Figure 16 As shown, with the previous reference Figure 10 As previously described, the chuck 18 is moved onto the semiconductor die 151 and vacuum-attached to the semiconductor die 151. Subsequently, the first and second lift pins 31, 32 are moved upward in unison to lift the semiconductor die 151. The chuck 18 rises in conjunction with the rise of the first and second lift pins 31, 32, and the separation of the wafer sheet 12 from the semiconductor die 151 begins at the periphery of the semiconductor die 151.

[0181] Then, the CPU 71 of the control unit 70 is as follows Figure 17 As shown, the first lift pins 31 are further raised to lift the semiconductor die 151 , and the chuck 18 is raised in conjunction with the raising of the first lift pins 31 , so that the semiconductor die 151 is picked up by the chuck 18 (picking up step).

[0182] As described above, the pickup device 110 of the embodiment raises the vertex 122b of the carrier 120 to the height Z1 so that the chip sheet 12 contacts the inner peripheral portion 122e of the adsorption surface 122a, and the chip sheet 12 is deformed upward along the inner peripheral portion 122e, and the gap between the side surface of the semiconductor bare chip 151 attached to the inner peripheral portion 122e and the upper end of the side surface of the adjacent semiconductor bare chip 152 and the semiconductor bare chip 153 is expanded to W1 which is wider than the initial W0. Moreover, the outer adsorption hole 124b is maintained at atmospheric pressure, the chip sheet 12 located on the outer peripheral portion 122f is kept away from the outer peripheral portion 122f of the adsorption surface 122a, and the gap between the semiconductor bare chips 152 and 153 attached to the upper surface 12a of the chip sheet 12 located on the upper side of the outer peripheral portion 122f and the upper ends of the side surfaces of the adjacent semiconductor bare chips 154 and 155 is maintained at the initial W0.

[0183] This can suppress the following phenomenon, that is, as shown in FIG. Figure 21 As in the pickup device 300 described above, during the pickup operation, the wafer sheet 12 is bent and deformed downward, and the gap between the upper ends of the side surfaces of the adjacent semiconductor bare chips 151 to 155 becomes smaller, so that the upper ends of the side surfaces of the semiconductor bare chips 151 to 155 come into contact with each other and become defective or cracked.

[0184] Next, refer to Figure 18 、 Figure 19 Next, another embodiment of the pickup device 110 is described as follows. The second pickup operation involves raising the height Z of the apex 122b of the stage 120 to Z2, vacuuming both the inner suction holes 124a and the outer suction holes 124b, and vacuum-adsorbing the wafer sheet 12 onto the inner and outer peripheries 122e and 122f of the suction surface 122a. The semiconductor die 151 is then picked up.

[0185] The CPU 71 of the control unit 70 is as follows Figure 18 As shown, the top 122b of the stage 120 is raised to a height Z2. Figure 4As described above, the height of the stage 120 is such that the lower surface 12b of the wafer sheet 12 contacts the suction surface 122a, extending from the vertex 122b to the connecting line 125a between the suction surface 122a and the corner 125. Therefore, when the vertex 122b of the stage 120 is raised to height Z2, the lower surface 12b of the wafer sheet 12 contacts the inner periphery 122e and outer periphery 122f of the suction surface 122a. Furthermore, the lower surface 12b of the wafer sheet 12 extends toward the outer periphery 122f, i.e., toward the tangent line 122d or the suction surface 122a on the connecting line 125a. In this state, a gap exists between the corner 125, which is located on the outer periphery of the connecting line 125a, and the lower surface 12b of the wafer sheet 12.

[0186] like Figure 18 As shown, the gap 14 between the semiconductor die 153 and the semiconductor die 155 is located at the upper surface 12a of the wafer sheet 12 that contacts the outer peripheral portion 122f. On the other hand, the semiconductor die 155 is located at the upper surface 12a of the wafer sheet 12 that extends in the tangential direction of the suction surface 122a on the connection line 125a. Therefore, the gap between the side surface of the semiconductor die 153 and the upper end of the side surface of the adjacent semiconductor die 155 is greater than Figure 5 Although the initial width W0 shown is wider, the gap is approximately half the size (W3) compared to when both semiconductor die 151 and adjacent semiconductor die 153 are located on the upper surface 12a of wafer sheet 12 in contact with suction surface 122a. (W3 ≈ W0 + (W1 - W0) / 2). Similarly, the gap between the top edges of each side surface of semiconductor die 152 and semiconductor die 154 is W3.

[0187] In this state, the CPU 71 of the control unit 70 opens the vacuum valve 64 and the vacuum valve 66 and sets the inner adsorption holes 124a and the outer adsorption holes 124b to vacuum, thereby vacuuming the lower surface 12b of the chip sheet 12 to the inner periphery 122e and the outer periphery 122f of the adsorption surface 122a.

[0188] Because the lower surface 12b of the wafer sheet 12 contacts the inner peripheral portion 122e, the wafer sheet 12 above the inner peripheral portion 122e and the outer peripheral portion 122f remains convex upward even when vacuum suction is applied. The gaps between the upper ends of the side surfaces of the semiconductor die 151 and 152, and between the upper ends of the side surfaces of the semiconductor die 151 and 153, are maintained at width W1. Furthermore, the lower surface 12b of the wafer sheet 12 outside the outer peripheral portion 122f extends toward the outer peripheral end of the outer peripheral portion 122f, i.e., in a direction tangential to the suction surface 122a on the circular line 122d or the connecting line 125a. Therefore, the gaps between the upper ends of the side surfaces of the semiconductor die 152 and 154, and between the upper ends of the side surfaces of the semiconductor die 153 and 155, are maintained at width W3, which is wider than W0.

[0189] Therefore, with reference Figure 16 、 Figure 17 The first picking action described above is similar to the above-described case, and the following phenomenon can be suppressed, that is, during the picking action, the chip sheet 12 is bent and deformed downward, and the gap between the upper ends of the side surfaces of the adjacent semiconductor bare chips 151 to 155 becomes smaller, so that the upper ends of the side surfaces of the semiconductor bare chips 151 to 155 come into contact and become defective or cracked.

[0190] Next, refer to Figure 20 , while explaining the separate use of the first picking action and the second picking action in the picking device 110. The positional relationship between the carrier 120 and the wafer sheet 12 when the carrier 120 is located in the center of the expansion ring 16 and pushes up the center of the wafer sheet 12 is as shown in FIG. Figure 12 As explained above, here, we refer to Figure 20 , while explaining the situation where the stage 120 comes to a position deviated from the center of the expansion ring 16.

[0191] like Figure 20 As shown, consider the following situation, that is, the center 121c of the carrier 120 deviates from the center of the expansion ring 16 and the distance from the center 121c to the fixed circular line 12f on one side is L5 and the distance on the other side is L6, where L5 is less than L6.

[0192] At this time, when the top 122b of the stage 120 is raised to the height Z4, as shown in FIG. Figure 20As shown, on one side, the angle θ5 of the lower surface 12b of the wafer sheet 12 relative to the horizontal line at Z = 0 is large, and the lower surface 12b of the wafer sheet 12 contacts the inner periphery 122e and outer periphery 122f of the suction surface 122a. However, on the other side, the angle of the lower surface 12b of the wafer sheet 12 relative to the horizontal line at Z = 0 is θ6, which is smaller than θ5. This results in the lower surface 12b of the wafer sheet 12 contacting the inner periphery 122e of the suction surface 122a, but not contacting the outer periphery 122f outside the circular line 122c. At this time, a gap exists between the outer periphery 122f on the other side and the lower surface 12b of the wafer sheet 12.

[0193] In this state, if the inner suction holes 124a and the outer suction holes 124b are set to vacuum as in the second pickup operation, the wafer sheet 12 placed with a gap on the outer peripheral portion 122f on the other side is pulled downward and adsorbed on the outer peripheral portion 122f. Figure 21 As in the pickup device 300 of the comparative example described above, the wafer sheet 12 is bent and deformed to bulge downward at the periphery of the stage 20. Therefore, the upper ends of the side surfaces of the semiconductor die 152 and the adjacent semiconductor die 154 located at the periphery of the stage 20 may contact each other, causing chipping or cracking.

[0194] Therefore, in the picking device 110, when the carrier 20 is moved from the center of the expansion ring 16 to pick up the semiconductor bare chip 151 attached to the outer peripheral part of the chip sheet 12, as in the first picking action, only the inner adsorption hole 124a is set to vacuum and the outer adsorption hole 124b is not set to vacuum to pick up the semiconductor bare chip 151; when picking up the semiconductor bare chip 151 attached to the central part of the chip sheet 12, as in the second picking action, the inner adsorption hole 124a and the outer adsorption hole 124b are set to vacuum to pick up the semiconductor bare chip 151.

[0195] Thus, even when picking up the semiconductor die 151 attached to the peripheral portion of the wafer sheet 12 , the semiconductor die 152 located at the peripheral edge of the stage 20 can be prevented from coming into contact with the upper end of the side surface of the adjacent semiconductor die 154 and being damaged or cracked.

[0196] Furthermore, in the above description, the adsorption surface 122a is divided into an inner peripheral portion 122e provided with an inner adsorption hole 124a and an outer peripheral portion 122f provided with an outer adsorption hole 124b, but it is not limited to this. For example, an intermediate portion can be provided between the inner peripheral portion 122e and the outer peripheral portion 122f to classify the adsorption surface 122a into three partitions, and the area of the vacuum adsorption chip sheet 12 is changed according to the deviation amount of the carrier 20 from the center of the expansion ring 16.

[0197] Moreover, the inner peripheral portion 122e having the inner adsorption holes 124a and the outer peripheral portion 122f having the outer adsorption holes 124b can be divided into multiple parts along the circumferential direction, and the area of the vacuum adsorption chip sheet 12 can be changed according to the position of the center of the carrier 20 relative to the center of the expansion ring 16.

Claims

1. A semiconductor die pickup device for picking up a semiconductor die attached to an upper surface of a wafer sheet, the semiconductor die pickup device comprising: A carrier, comprising an adsorption surface for adsorbing the lower surface of the wafer sheet and an opening provided on the adsorption surface; A stage driving mechanism drives the stage in an up-down direction; as well as A moving element is disposed in the opening of the carrier and moves in a manner such that the front end protrudes from the adsorption surface. The semiconductor die pickup device includes: A moving element driving mechanism for driving the moving element in an up-down direction; a chuck for picking up the semiconductor die; a vacuum device for setting the interior of the carrier to a vacuum; and The control unit adjusts the movement of the stage drive mechanism, the moving element drive mechanism, the chuck and the vacuum device, The carrier is cylindrical in shape, the adsorption surface is a spherical crown surface that is convexly curved upward, the opening of the carrier is arranged at the center of the adsorption surface, the adsorption surface includes an inner peripheral portion around the opening and an outer peripheral portion outside the inner peripheral portion, the inner peripheral portion includes an inner adsorption hole connected to the vacuum device, and the outer peripheral portion includes an outer adsorption hole connected to the vacuum device. The control unit raises the stage through the stage driving mechanism until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral portion of the stage, thereby pushing up the wafer sheet. After pushing up the wafer sheet, the inner suction holes are set to vacuum by the vacuum device so that the wafer sheet is sucked onto the inner peripheral portion of the suction surface. After the wafer sheet is adsorbed on the adsorption surface, the moving element is protruded from the adsorption surface by the moving element driving mechanism to push up the semiconductor die to be picked up from the bottom of the wafer sheet, and the chuck is used to pick up the semiconductor die from the wafer sheet.

2. The semiconductor die pickup device according to claim 1, wherein When pushing up the wafer sheet, the control unit raises the stage until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral portion of the stage. When the wafer sheet is adsorbed, the inner adsorption holes and the outer adsorption holes are set to a vacuum state by the vacuum device, so that the wafer sheet is adsorbed to the inner peripheral portion and the outer peripheral portion of the adsorption surface.

3. The semiconductor bare chip pickup device according to claim 2, characterized in that When pushing up the wafer sheet, the control unit raises the stage until the lower surface of the wafer sheet contacts a corner between a cylindrical side surface of the stage and the adsorption surface.

4. The semiconductor die pickup device according to claim 3, wherein The corner portion includes a curved surface connecting the side surface of the carrier and the adsorption surface, When pushing up the wafer sheet, the control unit raises the stage until the height of the ridgeline between the side surface of the stage and the adsorption surface at the corner becomes greater than the height of the lower surface of the wafer sheet at the side surface of the stage.

5. The semiconductor bare chip pickup device according to claim 2, wherein When the control unit picks up the semiconductor bare die attached to the upper surface of the peripheral portion of the wafer sheet, When pushing up the wafer sheet, the stage is raised until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral portion of the stage. When the wafer sheet is adsorbed, the inner adsorption holes are set to a vacuum by the vacuum device so that the wafer sheet is adsorbed to the inner peripheral portion of the adsorption surface. When the control unit picks up the semiconductor bare die attached to the upper surface of the central portion of the wafer sheet, When pushing up the wafer sheet, the stage is raised until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral portion of the stage. When the wafer sheet is adsorbed, the inner adsorption holes and the outer adsorption holes are set to a vacuum state by the vacuum device, so that the wafer sheet is adsorbed to the inner peripheral portion and the outer peripheral portion of the adsorption surface.

6. The semiconductor bare die pickup device according to any one of claims 1 to 5, characterized in that The moving element comprises: A first lift pin is disposed at the center of the carrier; and A cylindrical second ejector pin is disposed on the outer periphery of the first ejector pin. The moving element driving mechanism drives the first upper ejector pin and the second upper ejector pin in the up and down directions. When the control unit picks up the semiconductor bare chip, After the second lift pin is protruded from the suction surface by the moving element driving mechanism, the first lift pin is protruded to a position higher than a front end of the second lift pin.

7. A method for picking up a semiconductor die, for picking up a semiconductor die attached to an upper surface of a wafer sheet, the method comprising: A preparation step of preparing a pickup device, the pickup device comprising a carrier including a suction surface for sucking the lower surface of the wafer sheet and an opening provided in the suction surface, a moving element arranged in the opening of the carrier and moving with a front end protruding from the suction surface, and a chuck for picking up the semiconductor bare die, wherein the carrier is cylindrical in shape, the suction surface is a spherical crown surface having a predetermined radius and curved convexly upward, the opening of the carrier is arranged at the center of the suction surface, the suction surface includes an inner peripheral portion around the opening and an outer peripheral portion outside the inner peripheral portion, the inner peripheral portion includes inner suction holes, and the outer peripheral portion includes outer suction holes; a pushing-up step of raising the stage to push up the wafer sheet until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral portion of the stage; an adsorption step of setting the inner adsorption holes to a vacuum state after the pushing-up step to adsorb the wafer sheet onto the inner peripheral portion of the adsorption surface; and The picking-up step comprises: after the adsorption step, causing the moving element to protrude from the adsorption surface to push up the semiconductor die to be picked up from below the wafer sheet, and using the chuck to pick up the semiconductor die.

8. The method for picking up a semiconductor die according to claim 7, wherein The pushing-up step is to raise the stage until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral portion of the stage. The adsorption step is to set the inner adsorption holes and the outer adsorption holes to a vacuum state so as to adsorb the wafer sheet onto the inner peripheral portion and the outer peripheral portion of the adsorption surface.

9. The method for picking up a semiconductor die according to claim 8, wherein The pushing-up step is to raise the stage until the lower surface of the wafer sheet contacts a corner between a cylindrical side surface of the stage and the adsorption surface.

10. The method for picking up a semiconductor die according to claim 9, wherein In the semiconductor bare chip pickup device prepared in the preparation step, the corner portion includes a curved surface connecting the side surface of the carrier and the adsorption surface, The pushing-up step is to raise the stage until the height of the ridgeline between the side surface of the stage and the adsorption surface at the corner portion becomes higher than the height of the lower surface of the wafer sheet at the side surface of the stage.

11. The method for picking up a semiconductor die according to claim 8, wherein When picking up the semiconductor bare die attached to the upper surface of the peripheral portion of the wafer sheet, The pushing-up step is to raise the stage until the lower surface of the wafer sheet contacts the outer peripheral end of the inner peripheral portion of the stage. The adsorption step is to set the inner adsorption hole to a vacuum state so that the wafer sheet is adsorbed on the inner peripheral portion of the adsorption surface. When picking up the semiconductor die attached to the upper surface of the central portion of the wafer sheet, The pushing-up step is to raise the stage until the lower surface of the wafer sheet contacts the outer peripheral end of the outer peripheral portion of the stage. The adsorption step is to set the inner adsorption holes and the outer adsorption holes to a vacuum state so as to adsorb the wafer sheet onto the inner peripheral portion and the outer peripheral portion of the adsorption surface.

12. The method for picking up a semiconductor die according to any one of claims 7 to 11, characterized in that In the semiconductor die pickup device prepared in the preparation step, the moving element includes: a first lift pin disposed at the center of the carrier; and a cylindrical second ejector pin disposed on the outer periphery of the first ejector pin, The picking up step includes causing the second lift pin to protrude from the suction surface, causing the first lift pin to protrude to a position higher than a front end of the second lift pin, and using the chuck to pick up the semiconductor die.

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