Expansion method and expansion device

Abstract

To reduce the possibility of damaging a wafer.SOLUTION: An extension method for expanding an expanded sheet to which the ductile material layer side of a workpiece including a wafer divided along a line to be divided or formed with a starting point of division along the line to be divided, and a layer of ductile material laminated to the backside of the wafer is attached includes a cooling step 1002 of cooling the expanded sheet and the workpiece by bringing a cooling plate cooled to a predetermined temperature close to the expanded sheet to which the workpiece is attached without contacting the expanded sheet, and an expanding step 1003 of expanding the expanded sheet to divide the workpiece along the line to be divided after performing the cooling step 1002.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to an expansion method and an expansion device for expanding an expandable sheet to which a workpiece including at least a ductile material layer is adhered on the surface.

Background Art

[0002] Ductile material layers such as DAF (Die Attach Film) and metal films improve divisibility by expanding in a state where they are cooled to reduce ductility. Therefore, a device for cooling a workpiece to expand an expandable sheet has been proposed (see, for example, Patent Document 1).

[0003] When attempting to accommodate the expansion mechanism in a cooling chamber, the device becomes large. For example, in the device disclosed in Patent Document 1 above, the workpiece is cooled by a cooling plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the device disclosed in Patent Document 1, when the workpiece is cooled with the cooling plate in contact with the expandable sheet and the expandable sheet is expanded while the cooling plate remains in contact with the expandable sheet, the expandable sheet may rub on the cooling plate and damage the workpiece.

[0006] Therefore, conventionally, after once retracting the cooling plate in contact with the expandable sheet, the expandable sheet was expanded. However, when retracting the cooling plate, the expandable sheet was dragged by the cooling plate, and there was a risk of damage, especially for thin workpieces.

[0007] The object of the present invention is to provide a wafer expansion method and a wafer expansion apparatus that can reduce the risk of damaging the wafer. [Means for solving the problem]

[0008] To solve the above-mentioned problems and achieve the objective, the present invention provides an expansion method for expanding an expanded sheet to which a workpiece, comprising a wafer divided along a planned division line or having a division starting point formed along the planned division line, and a ductile material layer laminated on the back surface of the wafer, has the ductile material layer side of the expanded sheet to which the workpiece is attached is attached, comprising a cooling step of bringing a cooling plate cooled to a predetermined temperature close to the expanded sheet to which the workpiece is attached without contact, and cooling the expanded sheet and the workpiece, and after performing the cooling step, While maintaining the distance between the cooling surface of the cooling plate and the expanded sheet, the ends of the expanded sheet in the flow direction are moved away from each other along the flow direction, and the ends of the expanded sheet in the vertical direction are moved away from each other along the vertical direction. The invention is characterized by comprising an expansion step of expanding the expanded sheet to divide the workpiece along the planned division line.

[0009] The present invention provides an expansion device for expanding an expanded sheet to which a workpiece, comprising a wafer divided along a division line or having a division starting point formed along the division line, and a ductile material layer laminated on the back surface of the wafer, has a clamping unit having: a pair of first clamping parts arranged facing each other in a first direction, sandwiching the workpiece, and clamping the expanded sheet to which the workpiece is attached; and a pair of second clamping parts arranged facing each other in a second direction intersecting the first direction, sandwiching the workpiece, and clamping the expanded sheet to which the workpiece is attached; and the first clamping parts being moved in a direction moving toward and away from each other in the first direction. The device comprises a moving unit that moves the second clamping portion toward and toward each other in the second direction, a cooling plate having a cooling surface facing the area on which the workpiece is attached to the expanded sheet clamped between the first and second clamping portions of the clamping unit, a plate moving unit that moves the cooling plate toward and toward the area on which the workpiece is attached to the expanded sheet clamped between the first and second clamping portions of the clamping unit, and a control unit that controls each component, wherein the control unit brings the cooling surface of the cooling plate, cooled to a predetermined temperature, close to the area on which the workpiece is attached to the expanded sheet for a predetermined time without contact, While maintaining the distance between the cooling surface and the expanded sheet, The mobile unit a pair The first clamping portion is moved in a direction that separates it from each other in the first direction, and the a pair The second clamping portion is characterized by moving in a direction that separates them from each other in the second direction. [Effects of the Invention]

[0010] This invention has the effect of reducing the risk of damaging the wafer. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a perspective view showing an example configuration of the expansion device according to Embodiment 1. [Figure 2]Figure 2 is a perspective view showing the workpiece being processed by the expansion device shown in Figure 1. [Figure 3] Figure 3 is a schematic side view showing the cooling plate of the expansion device shown in Figure 1. [Figure 4] Figure 4 is a flowchart showing the flow of the extension method according to Embodiment 1. [Figure 5] Figure 5 is a schematic side view showing a partial cross-section of the clamping step of the expansion method shown in Figure 4. [Figure 6] Figure 6 is a schematic side view showing a partial cross-section of the cooling step of the expansion method shown in Figure 4. [Figure 7] Figure 7 is a schematic side view showing a partial cross-section of the start of the expansion step of the expansion method shown in Figure 4. [Figure 8] Figure 8 is a schematic side view showing a partial cross-section of the extension method after the extension step shown in Figure 4. [Figure 9] Figure 9 is a schematic side view showing a partial cross-section of the start of the expansion step of the expansion method according to Embodiment 2. [Figure 10] Figure 10 is a schematic side view showing a partial cross-section of the expansion method according to Embodiment 2 after the expansion step. [Figure 11] Figure 11 is a perspective view showing a modified example of the workpiece shown in Figure 2. [Modes for carrying out the invention]

[0012] Embodiments for carrying out the present invention will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that can be easily imagined by those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the present invention.

[0013] [Embodiment 1] An expansion device according to Embodiment 1 of the present invention will be described based on the drawings. FIG. 1 is a perspective view showing a configuration example of the expansion device according to Embodiment 1. FIG. 2 is a perspective view showing a workpiece to be processed by the expansion device shown in FIG. 1. FIG. 3 is a side view schematically showing a cooling plate of the expansion device shown in FIG. 1.

[0014] The expansion device 1 shown in FIG. 1 according to Embodiment 1 is a device that expands an expandable sheet 203 to which a workpiece 200 shown in FIG. 2 is attached. As shown in FIG. 2, the workpiece 200 is composed of a wafer 201 and a die attach film (hereinafter referred to as DAF) 202 which is a ductile material layer.

[0015] In Embodiment 1, the wafer 201 is a disc-shaped semiconductor wafer or an optical device wafer having a substrate such as silicon, sapphire, gallium arsenide, or SiC (silicon carbide). As shown in FIG. 2, devices 207 are formed in respective regions of the wafer 201 partitioned by a plurality of division planned lines 206 intersecting with each other on the surface 205.

[0016] The wafer 201 is irradiated with a laser beam having a wavelength that is transmissive with respect to the substrate from the back surface 208 side on the back side of the surface 205 along the division planned line 206, and a modified layer 209 (shown by a dotted line in FIG. 2) which is a division starting point is formed inside the substrate along the division planned line 206. The wafer 201 is divided into individual chips 210 starting from the modified layer 209. The chip 210 includes a part of the substrate divided along the division planned line 206 and a device 207 formed on the surface of the substrate, and a part of the DAF 202 divided on the back surface 208 of the substrate is attached thereto.

[0017] The modified layer 209 means a region in which the density, refractive index, mechanical strength, and other physical properties are different from those of the surroundings, and examples thereof include a melting treatment region, a crack region, an insulation breakdown region, a refractive index change region, and a region in which these regions are mixed.

[0018] DAF202 is an adhesive film for die bonding used to fix individually divided chips 210 to other chips or substrates. DAF202 is formed in a disc shape with a diameter larger than the diameter of the wafer 201. DAF202 is laminated on the back surface 208 of the wafer 201. The workpiece 200 has an expanded sheet 203 attached to DAF202.

[0019] The expanded sheet 203 is made of a stretchable resin and has thermal shrinkage properties, meaning it shrinks when heated. In Embodiment 1, the expanded sheet 203 is formed in a rectangular shape with a width and length greater than the diameter of the wafer 201 and DAF 202, and comprises a base layer made of a synthetic resin that is stretchable and thermally shrinkable, and an adhesive layer laminated on the base layer and attached to the wafer 201 via the DAF 202, and made of a synthetic resin that is stretchable and thermally shrinkable. The adhesive layer is to which the DAF 202 is attached, and the back surface 208 of the wafer 201 is attached via the DAF 202.

[0020] In Embodiment 1, the expanded sheet 203 has a DAF 202 attached to its adhesive layer beforehand, and is attached to the back surface 208 of the wafer 201 via the DAF 202, thus forming a so-called 2-in-1 tape.

[0021] The expanded sheet 203 is formed into a strip shape by, for example, stretching a heated synthetic resin along a first direction 211 while simultaneously stretching it in a second direction 212 that is perpendicular (i.e., intersecting) to the first direction 211. In Embodiment 1, the first direction 211 is the so-called flow direction (MD: Machine Direction), and the second direction 212 is the so-called vertical direction (TD: Transverse Direction).

[0022] The workpiece 200 with the above configuration is made up of a DAF 202 attached to the adhesive layer of an expanded sheet 203, with the back surface 208 of a wafer 201 attached to it.

[0023] The expansion device 1 according to Embodiment 1 shown in Figure 1 expands an expanded sheet 203 to which the DAF 202 side of the workpiece 200 is attached in a first direction 211 and a second direction 212, dividing the wafer 201, to which the modified layer 209 is formed as the dividing starting point, into individual chips 210 along the planned dividing line 206, and also divides the DAF 202 into chips 210, forming a gap between adjacent chips 210. Furthermore, the expansion device 1 expands the expanded sheet 203 to form a gap between adjacent chips 210, then attaches an annular frame (not shown) with an inner diameter larger than the diameters of the wafer 201 and DAF 202 to the expanded sheet 203, and also cuts the expanded sheet 203 between the inner and outer edges of the frame.

[0024] As shown in Figure 1, the expansion device 1 comprises a flat fixed base 2, a workpiece loading unit (not shown), a clamping unit 10, a moving unit 20, a cooling plate 30, a frame loading / unloading unit (not shown), a sheet cutting unit (not shown), and a control unit 100.

[0025] The workpiece loading unit loads the workpiece 200 onto the fixed base 2 of the expansion device 1. The clamping unit 10 holds the expanded sheet 203 to which the DAF 202 side of the workpiece 200 loaded by the workpiece loading unit is attached. The clamping unit 10 has a pair of first clamping parts 11-1 and a pair of second clamping parts 11-2. The first clamping parts 11-1 and the second clamping parts 11-2 clamp and hold the expanded sheet 203 to which the DAF 202 side of the workpiece 200 is attached, on the outer circumference of the wafer 201.

[0026] The same parts of the first clamping section 11-1 and the second clamping section 11-2 will be denoted by the same reference numerals in the description. The first clamping section 11-1 and the second clamping section 11-2 are each equipped with a columnar movable base 12 mounted on a fixed base 2.

[0027] Each pair of first clamping sections 11-1 is provided with a pair of first clamping members 13-1. The first clamping member 13-1 of one first clamping section 11-1 and the first clamping member 13-1 of the other first clamping section 11-1 are arranged facing each other, clamping the wafer 201 of the workpiece 200 in the first direction 211. In Embodiment 1, the first clamping member 13-1 of one first clamping section 11-1 and the first clamping member 13-1 of the other first clamping section 11-1 are arranged facing each other along the first direction 211. The pair of first clamping members 13-1 of each first clamping section 11-1 are formed in a straight line parallel to the second direction 212 and are spaced apart in the vertical direction.

[0028] One of the pair of first clamping members 13-1 of each first clamping section 11-1 is supported at the tip of a support arm 14 extending horizontally from the upper end of the movable base 12 of each first clamping section 11-1, and the other is supported at the tip of a support arm 14 extending horizontally from the central part of the movable base 12 of each first clamping section 11-1. The pair of first clamping members 13-1 of each first clamping section 11-1 support a plurality of cylindrical rollers 15 on their opposing surfaces so as to be rotatable around their axis. In the first clamping section 11-1, the axis of the rollers 15 is parallel to the first direction 211, and the rollers 15 are arranged at equal intervals in the second direction 212.

[0029] Furthermore, each of the pair of first clamping sections 11-1 is equipped with a member movement unit 16. The member movement unit 16 is provided on the movement base 12 of each of the first clamping sections 11-1.

[0030] The member movement unit 16 includes a motor 17 provided on the movement base 12 of each of the first clamping parts 11-1, a ball screw 18 rotated by the motor 17 around an axis parallel to the vertical direction, and a nut 19 that is screwed onto the ball screw 18 and connected to a support arm 14 that supports the first clamping member 13-1 at its tip.

[0031] The component movement unit 16 moves the nut 19, support arm 14, and first clamping member 13-1 toward or toward each other along the vertical direction by rotating the ball screw 18 around its axis using the motor 17. Hereafter, the direction toward or toward each other will be referred to as the proximity-to-apartmental direction. The component movement unit 16 can also move a pair of first clamping members 13-1 toward each other in the same direction vertically by rotating the ball screw 18 around its axis using the motor 17.

[0032] Each pair of second clamping sections 11-2 is provided with a pair of second clamping members 13-2. The second clamping members 13-2 of the pair of second clamping sections 11-2 are arranged facing each other, clamping the wafer 201 of the workpiece 200 in the second direction 212. In Embodiment 1, the second clamping members 13-2 of the pair of second clamping sections 11-2 face each other along the second direction 212. The pair of second clamping members 13-2 of each second clamping section 11-2 are formed in a straight line parallel to the first direction 211 and are spaced apart in the vertical direction.

[0033] One of the pair of second clamping members 13-2 of each second clamping section 11-2 is supported at the tip of a support arm 14 extending horizontally from the upper end of the movable base 12 of each second clamping section 11-2, and the other is supported at the tip of a support arm 14 extending horizontally from the central part of the movable base 12 of each second clamping section 11-2. The pair of second clamping members 13-2 of each second clamping section 11-2 support a plurality of cylindrical rollers 15 on their opposing surfaces so as to be rotatable around their axis. In the second clamping section 11-2, the axis of the rollers 15 is parallel to the second direction 212, and the rollers 15 are arranged at equal intervals in the first direction 211.

[0034] Furthermore, each of the pair of second clamping sections 11-2 is equipped with a member movement unit 16. The member movement unit 16 is provided on the movement base 12 of each of the second clamping sections 11-2.

[0035] The member movement unit 16 includes a motor 17 provided on the movement base 12 of each of the second clamping parts 11-2, a ball screw 18 rotated by the motor 17 around an axis parallel to the vertical direction, and a nut 19 that is screwed onto the ball screw 18 and connected to a support arm 14 that supports the second clamping member 13-2 at its tip.

[0036] The component moving unit 16 moves the nut 19, support arm 14, and second clamping member 13-2 in a vertical direction toward or toward each other by rotating the ball screw 18 around its axis using the motor 17. The component moving unit 16 can also move a pair of second clamping members 13-2 in the same direction vertically by rotating the ball screw 18 around its axis using the motor 17.

[0037] The clamping unit 10 works by having the member moving unit 16 move the clamping members 13-1 and 13-2 of the first clamping section 11-1 and the second clamping section 11-2 in a direction that brings them closer to each other in the vertical direction, thereby clamping the outer circumference of the wafer 201 of the expanded sheet 203 to which the DAF 202 side of the workpiece 200 is attached between the clamping members 13-1 and 13-2, and releasing the clamping of the expanded sheet 203 between the clamping members 13-1 and 13-2 by moving the clamping members 13-1 and 13-2 in a direction that moves them further apart in the vertical direction.

[0038] The moving unit 20 moves the first clamping members 13-1 of a pair of first clamping parts 11-1 toward and toward each other in a first direction 211, and moves the second clamping members 13-2 of a pair of second clamping parts 11-2 toward and toward each other in a second direction 212. The moving unit 20 comprises a pair of first-direction moving units 21-1 and a pair of second-direction moving units 21-2.

[0039] Each first directional movement unit 21-1 moves the movement base 12 of the first clamping part 11-1 along the first direction 211, thereby moving the first clamping members 13-1 of the pair of first clamping parts 11-1 toward and toward each other along the first direction 211.

[0040] Each second direction movement unit 21-2 moves the movement base 12 of the second clamping portion 11-2 along the second direction 212, thereby moving the second clamping members 13-2 of the pair of second clamping portions 11-2 toward and toward each other along the second direction 212.

[0041] Since the first directional movement unit 21-1 and the second directional movement unit 21-2 have substantially the same configuration, the same parts will be denoted by the same reference numerals and described accordingly.

[0042] The first direction movement unit 21-1 and the second direction movement unit 21-2 each have a motor 22 provided on the fixed base 2 and a ball screw 23 that is rotated around its axis by the motor 22 to move the movement base 12 of each clamping part 11-1, 11-2 in the first direction 211 or the second direction 212.

[0043] The first directional movement unit 21-1 and the second directional movement unit 21-2 expand the expanded sheet 203 held by the clamping parts 11-1 and 11-2 by moving them away from each other in the first direction 211 or the second direction 212, and release the expansion of the expanded sheet 203 held by the clamping parts 11-1 and 11-2 by moving them towards each other in the first direction 211 or the second direction 212.

[0044] In a plan view of the fixed base 2 of the expansion device 1, the cooling plate 30 is positioned below the expanded sheet 203, which is clamped between the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2 of the clamping unit 10, when viewed from the side, between the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2. The cooling plate 30 is provided on the fixed base 2 so as to be able to move up and down in directions perpendicular to both the first direction 211 and the second direction 212 by a plate moving unit 40 provided on the fixed base 2.

[0045] The cooling plate 30 is raised and lowered by the plate moving unit 40, thereby moving closer to and further away from the region 213 (shown in Figure 2) on the expanded sheet 203 to which the workpiece 200 is attached, which is held between the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2 of the clamping unit 10. Thus, the expansion device 1 includes a plate moving unit 40 that moves the cooling plate 30 in a direction toward and away from the region 213 on which the workpiece 200 is attached, which is held between the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2 of the clamping unit 10. In Embodiment 1, the plate moving unit 40 is an air cylinder having a rod that is extendable and retractable and has a cooling plate 30 attached to its upper end. When the rod extends, it brings the cooling plate 30 closer to the area 213 of the expanded sheet 203, and when the rod retracts, it moves the cooling plate 30 away from the area 213 of the expanded sheet 203.

[0046] In Embodiment 1, the cooling plate 30 is formed in a disc shape with a larger diameter than the wafer 201 and DAF 202, and is positioned coaxially with the wafer 201 and DAF 202 of the workpiece 200 in which the expanded sheet 203 is clamped by the clamping members 13-1 and 13-2 of the clamping portions 11-1 and 11-2 of the clamping unit 10. As shown in Figure 3, the cooling plate 30 comprises a disc-shaped Peltier element layer 31, a disc-shaped plate 32 laminated on one side of the Peltier element layer 31 facing the expanded sheet 203, and a disc-shaped heat dissipation plate 33 laminated on the other side of the Peltier element layer 31. In this invention, the planar shape of the cooling plate 30 may be a rectangle larger than the wafer 201 and DAF 202.

[0047] The Peltier element layer 31 includes a Peltier element that cools the plate 32 and heats the heat dissipation plate 33 when power is applied. The plate 32 and the heat dissipation plate 33 are made of a thermally conductive material (for example, metal). The plate 32 has a cooling surface 34 facing the expanded sheet 203, which is arranged parallel to the expanded sheet 203. That is, the cooling plate 30 has a cooling surface 34 that faces the region 213 of the expanded sheet 203 to which the workpiece 200 is attached, which is held between the first clamping portion 11-1 and the second clamping portion 11-2 of the clamping unit 10.

[0048] The cooling plate 30 cools the DAF 202 via the expanded sheet 203 by having the plate 32 close to the region 213 of the expanded sheet 203, and the Peltier element of the Peltier element layer 31 cools the plate 32.

[0049] The frame loading / unloading unit holds the frame by suction and attaches it to the expanded sheet 203 expanded by the clamping unit 10. The sheet cutting unit cuts the expanded sheet 203, which has been expanded by the clamping unit 10 and to which the frame has been attached, between the inner and outer edges of the frame. The frame loading / unloading unit holds the frame attached to the expanded sheet 203 that has been cut between the inner and outer edges of the frame and unloads the workpiece 200 outside the expansion device 1.

[0050] The control unit 100 controls each component of the expansion device 1 to cause the expansion device 1 to perform expansion operations such as expanding the expand sheet 203 of the workpiece 200 and attaching the frame to the expand sheet 203. The control unit 100 is a computer having an arithmetic processing unit with a microprocessor such as a CPU (central processing unit), a storage device with memory such as ROM (read-only memory) or RAM (random access memory), and an input / output interface device. The arithmetic processing unit of the control unit 100 performs arithmetic processing according to the computer program stored in the storage device and outputs control signals for controlling the expansion device 1 to each component of the expansion device 1 via the input / output interface device.

[0051] Furthermore, the control unit 100 is connected to a display unit, which consists of a liquid crystal display device that displays various information and images, and an input unit used by the operator to register processing content information. The input unit consists of at least one of the following: a touch panel provided on the display unit and an external input device such as a keyboard.

[0052] Next, this specification will describe the expansion method according to Embodiment 1 with reference to the drawings. Figure 4 is a flowchart showing the flow of the expansion method according to Embodiment 1. The expansion method according to Embodiment 1 is a method for expanding an expanded sheet 203 to which the DAF 202 side of the workpiece 200 is attached.

[0053] The expansion method according to Embodiment 1 is also an expansion operation that expands the expand sheet 203 of the expansion device 1 described above. The expansion device 1 receives processing content information input by the operator by operating the input unit, and when it receives a start instruction for a processing operation input by the operator by operating the input unit, the control unit 100 controls each component of the expansion device 1 to start the expansion operation, i.e., the expansion method.

[0054] When the expansion operation, or expansion method, is started, the control unit 100 of the expansion device 1 applies power to the Peltier element in the Peltier element layer 31 of the cooling plate 30 to start cooling the plate 32. The plate 32 of the cooling plate 30 is cooled to a predetermined temperature (for example, from -20°C to 0°C). Also, when the expansion operation, or expansion method, is started, the control unit 100 of the expansion device 1 moves the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2 apart from each other using the member moving unit 16, and moves the clamping members 13-1 and 13-2 of the clamping parts 11-1 and 11-2 closer to each other using the moving unit 20. As shown in Figure 4, the expansion method comprises a clamping step 1001, a cooling step 1002, an expansion step 1003, and an unloading step 1004.

[0055] (Clamping step) Figure 5 is a schematic side view showing a partial cross-section of the clamping step of the expansion method shown in Figure 4. The clamping step 1001 is the step of clamping the expanded sheet 203 between the clamping members 13-1 and 13-2 of the clamping portions 11-1 and 11-2 of the clamping unit 10.

[0056] In the clamping step 1001, the control unit 100 of the expansion device 1 causes the workpiece 200 to be loaded into the workpiece loading unit, and positions the expanded sheet 203 attached to the DAF 202 side of the workpiece 200 between the spaced-apart clamping members 13-1 and 13-2 of the clamping sections 11-1 and 11-2. In the clamping step 1001, the control unit 100 of the expansion device 1 causes the spaced-apart clamping members 13-1 and 13-2 of the clamping sections 11-1 and 11-2 to be brought closer together by the member moving unit 16, and as shown in Figure 5, the expanded sheet 203 is clamped between the first clamping member 13-1 of the pair of first clamping sections 11-1 and between the second clamping members 13-2 of the pair of second clamping sections 11-2.

[0057] (Cooling step) Figure 6 is a schematic side view showing a partial cross-section of the cooling step of the expansion method shown in Figure 4. The cooling step 1002 is a step in which a cooling plate 30 cooled to a predetermined temperature is brought close to the expanded sheet 203 to which the workpiece 200 is attached, without contact, in order to cool the expanded sheet 203 and the workpiece 200.

[0058] In cooling step 1002, the control unit 100 of the expansion device 1 moves the cooling plate 30 to the plate moving unit 40 as shown in Figure 6, bringing its surface 34 closer to the region 213 of the expanded sheet 203. In cooling step 1002, the expansion device 1 brings the surface 34 of the plate 32, which has been cooled to a predetermined temperature, close to the region 213 of the expanded sheet 203 to which the workpiece 200 is attached, without contact (i.e., maintaining a distance from the region 213), for a predetermined time. The distance between the expanded sheet 203 and the surface 34, and the predetermined time in cooling step 1002, are the distance and time required for the DAF 202 attached to the expanded sheet 203 to be cooled to the aforementioned predetermined temperature (for example, -2°C in Embodiment 1).

[0059] (Extension step) Figure 7 is a schematic side view showing a partial cross-section of the expansion step at the start of the expansion method shown in Figure 4. Figure 8 is a schematic side view showing a partial cross-section after the expansion step of the expansion method shown in Figure 4. The expansion step 1003 is a step in which, after performing the cooling step 1002, the expanded sheet 203 is expanded to divide the workpiece 200, i.e., the wafer 201 and DAF 202, along the planned division line 206.

[0060] In expansion step 1003, with the expanded sheet 203 clamped between the first clamping members 13-1 of the pair of first clamping parts 11-1 and between the second clamping members 13-2 of the pair of second clamping parts 11-2, the control unit 100 of the expansion device 1 controls the moving unit 20 to move the first clamping members 13-1 of the first clamping parts 11-1 in a direction away from each other in the first direction 211, as shown by the arrow 300 in Figure 7, and at the same time move the second clamping members 13-2 of the second clamping parts 11-2 in a direction away from each other in the second direction 212.

[0061] As a result of the expansion device 1's movement, the moving unit 20 moves the first clamping members 13-1 of the pair of first clamping parts 11-1 away from each other along the first direction 211, and moves the second clamping members 13-2 of the pair of second clamping parts 11-2 away from each other along the second direction 212, thereby expanding the expanded sheet 203 in both the first direction 211 and the second direction 212.

[0062] When tensile forces are applied to the expanded sheet 203 to which the workpiece 200 is attached in both the first direction 211 and the second direction 212, as shown in Figure 8, the wafer 201 is divided into individual chips 210 along the planned division line 206, with the modified layer 209 as the starting point, because a modified layer 209 has been formed along the planned division line 206, and a gap is formed between adjacent chips 210. Also, when tensile forces are applied radially to the expanded sheet 203, the DAF 202 breaks along the modified layer 209, i.e., the planned division line 206, for each individual chip 210.

[0063] In Embodiment 1, the extension step 1003 involved moving the clamping members 13-1 and 13-2 of the clamping portions 11-1 and 11-2 simultaneously in a direction away from each other along the first direction 211 or the second direction 212. However, the present invention is not limited to this, and the first clamping member 13-1 of the first clamping portion 11-1 may be moved in a direction away from each other along the first direction 211, and then the second clamping member 13-2 of the second clamping portion 11-2 may be moved in a direction away from each other along the second direction 212.

[0064] (Removal step) The unloading step 1004 is the step of unloading the workpiece 200 attached to the expanded sheet 203. In the unloading step 1004, with the expanded sheet 203 in the expanded state, the control unit 100 of the expansion device 1 causes the frame loading / unloading unit to attach the frame to the expanded sheet 203, the cutting unit cuts the expanded sheet 203 between the inner and outer edges of the frame, and then the frame loading / unloading unit unloads the workpiece 200, thus ending the expansion operation, i.e., the expansion method.

[0065] The expansion method and expansion apparatus 1 according to Embodiment 1 described above cool the expanded sheet 203 and the workpiece 200 by bringing the cooling plate 30 close to the expanded sheet 203 without contacting it, thereby suppressing the expanded sheet 203 from rubbing against the cooling plate 30 in the expansion step 1003.

[0066] Furthermore, the expansion method and expansion device 1 according to Embodiment 1 cool the expanded sheet 203 and the workpiece 200 by bringing the cooling plate 30 close to the expanded sheet 203 without contacting it. Therefore, it is possible to suppress the movement of the expanded sheet 203 along with the movement of the cooling plate 30.

[0067] As a result, the expansion method and expansion apparatus 1 according to Embodiment 1 have the effect of reducing the risk of damaging the wafer 201.

[0068] [Embodiment 2] The expansion method according to Embodiment 2 of the present invention will now be described with reference to the drawings. Figure 9 is a schematic side view showing a partial cross-section of the expansion method according to Embodiment 2 at the start of the expansion step. Figure 10 is a schematic side view showing a partial cross-section of the expansion method according to Embodiment 2 after the expansion step. Note that the same reference numerals are used for the same parts as in Embodiment 1 in Figures 9 and 10, and their descriptions are omitted.

[0069] The expansion method according to Embodiment 2 is the same as Embodiment 1, except that the expansion step 1003 is different. In the expansion method according to Embodiment 2, after the control unit 100 of the expansion device 1 lowers the cooling plate 30 onto the plate moving unit 40, the moving unit 20 moves the first clamping member 13-1 of the first clamping portion 11-1 in a direction away from each other in the first direction 211, as shown by the arrow 300 in Figure 9, and at the same time moves the second clamping member 13-2 of the second clamping portion 11-2 in a direction away from each other in the second direction 212.

[0070] In the expansion method according to Embodiment 2, in expansion step 1003, as shown in Figure 10, the expansion device 1 expands the expanded sheet 203 along the first direction 211 and the second direction 212, dividing the wafer 201 into individual chips 210 along the division line 206 with the modified layer 209 as the starting point, and forming a gap between adjacent chips 210. In addition, in the expansion method according to Embodiment 2, in expansion step 1003, the expansion device 1 breaks the DAF 202 along the modified layer 209, i.e., the division line 206, for each individual chip 210.

[0071] The expansion method and expansion apparatus 1 according to Embodiment 2 cool the expanded sheet 203 and the workpiece 200 by bringing the cooling plate 30 close to the expanded sheet 203 without contacting it. This suppresses the expanded sheet 203 from rubbing against the cooling plate 30 during the expansion step 1003, and also suppresses the expanded sheet 203 from moving along with the cooling plate 30. As a result, the expansion method and expansion apparatus 1 according to Embodiment 2 have the effect of reducing the risk of damaging the wafer 201, similar to Embodiment 1.

[0072] It should be noted that the present invention is not limited to the embodiments described above. That is, it can be implemented with various modifications without departing from the core principles of the present invention.

[0073] In Embodiments 1 and 2, a modified layer 209 was formed as the splitting starting point, but the present invention is not limited to this, and a laser-processed groove or a cutting groove may be formed as the splitting starting point. Also, in Embodiments 1 and 2, DAF202 was attached as a ductile material layer and laminated on the back surface 208 of the wafer 201, but in the present invention, a metal layer made of metal may be laminated on the back surface 208 of the wafer 201 as a ductile material layer.

[0074] Furthermore, in the present invention, the expansion method and expansion apparatus 1 may be configured such that the wafer 201 of the workpiece 200 is divided into individual chips 210 along the division line 206 by division grooves 214 formed on the division line 206 as shown in Figure 11.

[0075] Figure 11 is a perspective view showing a modified example of the workpiece shown in Figure 2. In Figure 11, the same reference numerals are used for the same parts as in Embodiment 1, and their descriptions are omitted. The dividing groove 214 penetrates the wafer 201 and divides the wafer 201 into individual chips 210, and is formed by cutting or laser ablation of the wafer 201.

[0076] In other words, in the present invention, the expansion method and expansion apparatus 1 may be a method or apparatus for expanding an expanded sheet 203 to which the DAF202 side of a workpiece 200, which consists of a wafer 201 divided along a division line 206 and a ductile material layer DAF202, is attached. In the expansion step 1003, the DAF202 of the workpiece 200 is divided into individual chips 210 along the division line 206, and the spacing between the chips 210 may be widened compared to before the expansion step 1003. In short, the expansion method and expansion apparatus 1 of the present invention only requires that in the expansion step 1003, at least the DAF202 of the workpiece 200 be divided along the division line 206. [Explanation of Symbols]

[0077] 1. Expansion device 10 Clamping Unit 11-1 First clamping part 11-2 Second clamping part 13-1 First clamping member (clamping member) 13-2 Second clamping member (clamping member) 20 Mobile Units 30 Cooling Plates 34 Surface (cooling surface) 40 Plate Transfer Unit 100 control units 200 Workpiece 201 wafer 203 Expanded Sheet (Ductile Material Layer) 206 planned division lines 208 Back side 209 Modified layer (starting point of splitting) 211 First direction 212 Second direction 213 areas 1002 Cooling step 1003 Extension Step

Claims

1. An expansion method for expanding an expanded sheet to which the ductile material layer side of a workpiece is attached, the workpiece comprising a wafer divided along a planned division line or having a division starting point formed along the planned division line, and a ductile material layer laminated on the back surface of the wafer, A cooling step involves bringing a cooling plate, cooled to a predetermined temperature, close to the expanded sheet to which the workpiece is attached, without contact, to cool the expanded sheet and the workpiece. An expansion method comprising: performing the cooling step, and then, while maintaining the distance between the cooling surface of the cooling plate and the expanded sheet, moving both ends of the expanded sheet in the flow direction away from each other along the flow direction, and moving both ends of the expanded sheet in the vertical direction away from each other along the vertical direction, thereby expanding the expanded sheet and dividing the workpiece along the planned division line.

2. An expansion device for expanding an expanded sheet to which the ductile material layer side of a workpiece, which consists of a wafer divided along a planned division line or having a division starting point formed along the planned division line, and a ductile material layer laminated on the back surface of the wafer, is attached, A clamping unit having: a pair of first clamping parts arranged opposite to each other in a first direction, sandwiching the workpiece and clamping the expanded sheet to which the workpiece is attached; and a pair of second clamping parts arranged opposite to each other in a second direction intersecting the first direction, sandwiching the workpiece and clamping the expanded sheet to which the workpiece is attached; A moving unit that moves the first clamping portion in a direction toward and toward each other in the first direction, and moves the second clamping portion in a direction toward and toward each other in the second direction, A cooling plate having a cooling surface facing the area of ​​the expanded sheet to which the workpiece is attached, which is clamped between the first and second clamping portions of the clamping unit, A plate moving unit moves the cooling plate in a direction toward or away from the area on the expanded sheet, which is clamped between the first and second clamping portions of the clamping unit, to which the workpiece is attached. It comprises a control unit that controls each component, The control unit moves the cooling plate, cooled to a predetermined temperature, close to the area of ​​the expanded sheet to which the workpiece is attached for a predetermined time without contacting it, and then, while maintaining the distance between the cooling plate and the expanded sheet, moves the pair of first clamping portions away from each other in the first direction and moves the pair of second clamping portions away from each other in the second direction. An expansion device characterized by the following features.

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