Carrier plate removal procedure

Abstract

Carrier plate removal method for removing a carrier plate (3) from a workpiece (7) arranged on an upper surface (3a) of the carrier plate (3) via a temporary bonding layer (5), wherein the carrier plate removal method comprises: a step-section training step of forming a step section (1a) in which the workpiece (7) projects laterally compared to the carrier plate (3) by machining the carrier plate (3) to remove a circumferential section (3c) of the carrier plate (3) along a circumferential edge of the carrier plate (3) from one side of the lower surface (3a) opposite the upper surface (3a) of the carrier plate (3); a carrier plate holding step of holding the carrier plate (3) by a carrier plate holding unit (24) after performing the step section training step; and a removal step of removing the carrier plate (3) from the workpiece (7) by applying a force from the side of the carrier plate (3) to the step section (1a) and moving the workpiece (7) in a direction of separation from the carrier plate (3) after performing the step section formation step.

Description

BACKGROUND OF THE INVENTIONField of the invention

[0001] The present invention relates to a carrier plate removing method for removing a carrier plate from a workpiece, on an upper surface of the carrier plate is provided via a temporary bonding layer. Description of the state of the art

[0002] In an electronic device such as a mobile phone or a personal computer, a component chip including a component such as an electronic circuit has become an essential component. The component chip is obtained, for example, by dividing the upper surface of a wafer made of a semiconductor material such as silicon into a plurality of regions along planned dividing lines (streets), forming a component in each of the regions, and then dividing the wafer along the planned dividing lines.

[0003] The component die obtained by a method as described above is attached to a mother substrate for a chip-size package (CSP), for example, electrically connected to terminals of the mother substrate or the like by a method such as wire bonding, and then sealed with a molded resin. When a packaged component is formed by sealing the component die with the molded resin in this way, the component die can be protected from external influences such as shock, light, heat, and water.

[0004] In recent years, a packaging technology called fan-out wafer-level packaging (FOWLP) has begun to be used, in which package terminals are formed outside the device die area using wafer-level rewiring technology (see, for example, JP 2016 - 201519 A). Additionally, a packaging technology called fan-out panel-level packaging (FOPLP) has been proposed, in which packaged devices are fabricated en bloc on a panel level larger than a wafer (typically a glass substrate used to fabricate a liquid crystal panel).

[0005] In FOPLP, for example, a wiring layer (redistribution layer (RDL)) is formed on the upper surface of a carrier board, which serves as a temporary substrate, via a temporary bonding layer, and component chips are connected to the wiring layer. Next, a package board is obtained by sealing the component chips with a molding resin. Afterward, the package board is thinned by a process such as grinding, and then the package board is divided. This completes the packaged components.

[0006] Further information helpful for understanding the present invention can be found in DE 10 2014 207 012 A1. This document relates to a method for machining a plate-shaped workpiece, including an arranging step for attaching a plate-shaped workpiece to a holding plate, a joining step for irradiating an outer peripheral portion of the workpiece attached to the holding plate, and a machining step for machining the workpiece after the joining step. SUMMARY OF THE INVENTION

[0007] For example, in the FOPLP described above, the carrier plate is removed from the packing components after the packing plate has been divided into the packing components. Specifically, each packing component is removed from the carrier plate. However, if the packing components are small in size, it is difficult to remove the packing components from the carrier plate.

[0008] On the other hand, it is conceivable that the carrier plate is peeled off and removed from the packing plate before the packing plate is divided into the packing components. However, since the bonding strength of the temporary bonding layer is strong to a certain extent, it is difficult to peel the carrier plate off the packing plate without damaging the packing plate and the carrier plate.

[0009] It is therefore an object of the present invention to provide a carrier plate removal method which enables a carrier plate to be easily removed from a workpiece such as a packing plate.

[0010] According to one aspect of the present invention, a carrier plate removing method for removing a carrier plate from a workpiece disposed on an upper surface of the carrier plate via a temporary bonding layer is provided.The carrier plate removing method includes: a step portion forming step of forming a step portion in which the workpiece protrudes laterally compared to the carrier plate by machining the carrier plate to remove a peripheral portion of the carrier plate along a peripheral edge of the carrier plate from a lower surface side opposite to the upper surface of the carrier plate; a carrier plate holding step of holding the carrier plate by a carrier plate holding unit after performing the step portion forming step; and a removing step of removing the carrier plate from the workpiece by applying a force from the carrier plate side to the step portion and moving the workpiece in a direction of separation from the carrier plate after performing the step portion forming step.

[0011] In the removal step, the workpiece may be moved in the direction of separation from the support plate by the force applied to the step portion. The support plate removal method may further include a workpiece holding step of holding the workpiece by a workpiece holding unit before performing the removal step. Additionally, preferably, in the removal step, the support plate may be removed from the workpiece by applying the force to the step portion by moving the support plate holding unit relative to the workpiece holding unit and an external force applying member in a state where the external force applying member is kept in contact with the step portion from the support plate side.In addition, in the removing step, a starting point region serving as a starting point at a time of removing the carrier plate from the workpiece may be formed in the provisional bonding layer by curving the peripheral portion of the carrier plate in a direction of separation from the workpiece before moving the carrier plate holding unit relative to the workpiece holding unit and the external force applying member.

[0012] Additionally, in the removal step, the workpiece may be moved in a direction of separation from the support plate after a starting point region serving as a starting point at the time of removal of the support plate from the workpiece is formed in the provisional bonding layer by curving a peripheral portion of the workpiece in a direction of separation from the support plate by the force applied to the step portion. The support plate removal method may further include a workpiece holding step of holding the workpiece by a workpiece holding unit before performing the removal step.

[0013] In addition, preferably, in the removing step, the support plate is removed from the workpiece by applying the force to the step portion after a fluid is sprayed between the workpiece and the support plate or while the fluid is sprayed between the workpiece and the support plate.

[0014] Additionally, in the removal step, it is preferable that the support plate is removed from the workpiece by applying the force to the step portion in a state where the workpiece and the support plate are immersed in a liquid. In the removal step, it is preferable that the support plate is removed from the workpiece by applying the force to the step portion by pressing an external force applying member, to which vibration is applied, against the step portion in a state where the workpiece and the support plate are immersed in the liquid. Alternatively, in the removal step, it is preferable that the support plate is removed from the workpiece by applying the force to the step portion, in a state where the workpiece and the support plate are immersed in the liquid, and applying vibration to the liquid. The liquid may include a surfactant.

[0015] In the carrier plate removal method according to one aspect of the present invention, the step portion where the workpiece protrudes laterally relative to the carrier plate is formed by machining the carrier plate to remove the peripheral portion of the carrier plate along the peripheral edge of the carrier plate from the side of the lower surface of the carrier plate. Thus, the carrier plate can be easily removed from the workpiece by applying force to the step portion from the side of the carrier plate.

[0016] The above and other objects, features and advantages of the present invention and the modes for carrying them out will become more apparent and the invention itself will be best understood by studying the following description and the appended claims with reference to the attached drawings which show a preferred embodiment of the invention. SHORT DESCRIPTION OF THE FIGURES Fig. 1A is a sectional view showing an example of a configuration of a composite substrate including a support plate and a workpiece; Fig. 1B is a sectional view showing a state in which the workpiece side of the composite substrate is held in a step portion forming step; Fig. 2A is a sectional view showing a state in which a step portion is formed on the composite substrate in the step portion forming step; Fig. 2B is a sectional view illustrating a state in which the step portion is formed on the entire peripheral portion of the composite substrate; Fig. 3A is a sectional view showing a carrier plate holding step; Fig. 3B is a sectional view illustrating a removal step; Fig. 3C is a sectional view showing a state in which the support plate is removed from the workpiece; Fig. 4A is a sectional view showing a removing step in a first modification; Fig. 4B is a sectional view illustrating a removing step in a second modification; Fig. 5A is a sectional view showing a platen holding step and a workpiece holding step in a third modification; Fig. 5B is a sectional view showing a state in which an external force applying member is brought into contact with the step portion in a removing step in the third modification; Fig. 5C is a sectional view illustrating a state in which a platen holding unit is moved upward relative to the external force applying member and a workpiece holding unit in the removing step in the third modification; Fig. 6A is a sectional view illustrating a state in which the external force applying member is brought into contact with the step portion in a removing step in a fourth modification; Fig. 6B is a sectional view showing a state in which a region serving as a starting point at the time of peeling the workpiece from the support plate is formed in a provisional bonding layer in the removing step in the fourth modification; Fig. 6C is a sectional view illustrating a state in which the workpiece is peeled off from the support plate in the removing step in the fourth modification; Fig. 7A is a sectional view showing a workpiece holding step in a fifth modification; Fig. 7B is a sectional view illustrating a state in which a region serving as a starting point at the time of peeling the workpiece from the support plate is formed in the provisional bonding layer in a removing step in the fifth modification; and Fig. 7C is a sectional view illustrating a state in which the workpiece is peeled off from the support plate in the removing step in the fifth modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] An embodiment according to one aspect of the present invention will be described below with reference to the accompanying drawings. A carrier plate removal method according to the present embodiment is used to remove a carrier plate from a workpiece provided via a temporary bonding layer on the upper surface of the carrier plate. The carrier plate removal method according to the present embodiment includes a step portion forming step (see Fig. 1B, Fig. 2A and Fig. 2B), a carrier plate holding step (see Fig. 3A) and a removal step (see Fig. 3B and Fig. 3C).

[0018] The step portion forming step forms a step portion of the workpiece and the support plate by causing a cutting blade to cut into a peripheral portion of the support plate along a peripheral edge of the support plate from a side of a lower surface opposite the upper surface of the support plate provided with the workpiece, thereby removing the peripheral portion of the support plate. The support plate holding step holds the support plate from above in a state where the support plate is arranged above the workpiece.

[0019] The removal step removes the support plate from the workpiece by applying a downward force to the workpiece side of the step portion by an external force applying member (pressure member), and moving the workpiece in a direction to separate it from the support plate. The support plate removal method according to the present embodiment will be described in detail below.

[0020] Fig. 1A is a sectional view showing an example of a configuration of a composite substrate 1 used in the carrier plate removing method according to the present embodiment. The composite substrate 1 includes, for example, a carrier plate 3 made of an insulating material such as soda glass, borosilicate glass, or quartz glass. The carrier plate 3 has, for example, a substantially flat first surface (upper surface) 3a and a second surface (lower surface) 3b on a side opposite to the first surface 3a. The carrier plate 3 is rectangular in plan view from the first surface 3a side or the second surface 3b side. The thickness of the carrier plate 3 is, for example, 2 mm or less, or typically 1.1 mm.

[0021] Note that, although the support plate 3 is formed of an insulating material such as soda glass, borosilicate glass, or quartz glass in the present embodiment, the material, shape, structure, size, and the like of the support plate 3 are not particularly limited. For example, a plate formed of a material such as a semiconductor, ceramic, plastic, or metal, or the like, may also be used as the support plate 3. A disk-shaped semiconductor wafer or the like may also be used as the support plate 3.

[0022] A workpiece 7 is provided via a temporary bonding layer 5 on the first surface 3a side of the support plate 3. The temporary bonding layer 5 is formed, for example, on substantially the entire first surface 3a by overlaying a metallic foil, an insulating foil, or the like. The temporary bonding layer 5 has a function of bonding the support plate 3 and the workpiece 7 together. Additionally, the temporary bonding layer 5 may be formed by a plastic film or the like that functions as an adhesive.

[0023] The thickness of the provisional bonding layer 5 is, for example, 20 µm or less, or typically about 0.6 µm. When the carrier plate 3 is peeled off and removed from the workpiece 7 in the removal step to be described later, the provisional bonding layer 5 is divided into a first part 5a (see Fig. 3C), which adheres closely to the side of the support plate 3, and a second part 5b (see Fig. 3C), which adheres closely to the side of the workpiece 7.

[0024] The workpiece 7 is also referred to, for example, as a packaging board, packaging wafer, or the like. The workpiece 7 includes a wiring layer (RDL) (not shown) in contact with the provisional interconnect layer 5, a plurality of component chips 9 connected to the wiring layer, and a molded plastic layer 11 sealing each component chip 9. The workpiece 7 is formed, for example, in substantially the same size and shape as the carrier board 3 in plan view. In addition, the thickness of the workpiece 7 is, for example, 1.5 mm or less, or is typically 0.6 mm.

[0025] Meanwhile, the first surface (upper surface) 7a side of the workpiece 7 may be machined by a method such as grinding. Additionally, planned dividing lines (planned cutting lines) are defined in regions between adjacent component chips 9 within the workpiece 7. The workpiece 7 is divided into a plurality of workpiece parts, each having one or more component chips 9, by cutting the workpiece 7 along optional planned dividing lines.

[0026] When the workpiece 7 (or workpiece pieces) is cut along all planned dividing lines, a plurality of packaged components corresponding to the respective component chips 9 are obtained. However, the material, shape, structure, size, and the like of the workpiece 7 are not particularly limited. For example, the workpiece 7 may be formed primarily by the wiring layer and may not include the component chips 9, the molded plastic layer 11, or the like.

[0027] The carrier plate removal method according to the present embodiment first performs the step portion forming step of forming a step portion in a peripheral portion of the composite substrate 1 as described above. Specifically, first, the workpiece 7 side of the composite substrate 1 is held, and the carrier plate 3 side is exposed upward. Fig. Fig. 1B is a sectional view showing a state in which the workpiece 7 side of the composite substrate 1 is held in the step portion forming step. Meanwhile, in Fig. 1B a part of the components is represented by a functional block.

[0028] This stage training step is carried out using a Fig. 1B and the like. The cutting device 2 includes a chuck table 4 for holding the composite substrate 1. The chuck table 4 includes, for example, a cylindrical frame body 6 formed of a metallic material such as stainless steel, and a holding plate 8 formed of a porous material and disposed in an upper portion of the frame body 6.

[0029] The upper surface of the holding plate 8 is a holding surface 8a for sucking and holding the workpiece 7 side of the composite substrate 1. The lower surface side of the holding plate 8 is connected to a suction source 12 via a flow line 6a provided in the frame body 6, a valve 10, and the like. Therefore, when the valve 10 is opened, a negative pressure from the suction source 12 can act on the holding surface 8a.

[0030] The chuck table 4 (frame body 6) is coupled to a rotary drive source (not shown) such as a motor, and is rotated about a rotation axis substantially perpendicular to the above-described support surface 8a by a force generated by the rotary drive source. In addition, the chuck table 4 (frame body 6) is supported by a machining feed mechanism (not shown) and thereby moved in a machining feed direction substantially parallel to the above-described support surface 8a.

[0031] When the side of the workpiece 7 of the composite substrate 1 is held and the side of the carrier plate 3 is exposed upwards, as for example in Fig. As shown in Fig. 1B, the first surface 7a of the workpiece 7 is brought into contact with the holding surface 8a of the chuck table 4. Then, the valve 10 is opened to cause a negative pressure from the suction source 12 to act on the holding surface 8a. As a result, the workpiece 7 side of the composite substrate 1 is held by the chuck table 4, and the support plate 3 side is exposed upward.

[0032] After the workpiece 7 side of the composite substrate 1 is held and the support plate 3 side is exposed upward, a step portion is formed on the composite substrate 1 by machining the support plate 3 along a peripheral edge of the support plate 3. Fig. 2A is a sectional view showing a state in which a step portion 1a is formed on the composite substrate 1 in the step portion forming step. Meanwhile, in Fig. 2A a part of the components is represented by a functional block.

[0033] As in Fig. As shown in FIG. 2A, a cutting unit 14 is arranged above the clamping table 4. The cutting unit 14 includes a spindle 16 having a rotational axis substantially parallel to the surface 8a. An annular cutting blade 18 formed by distributing abrasive grains in a bonding material is fitted to one end of the spindle 16.

[0034] A rotational drive source (not shown) such as a motor is coupled to the other end of the spindle 16. The cutting blade 18 attached to one end of the spindle 16 is rotated by a force generated by the rotational drive source. The cutting unit 14 is supported by, for example, a lifting and lowering mechanism (not shown) and an index feed mechanism (not shown), and is thereby moved in a vertical direction substantially perpendicular to the support surface 8a and an index feed direction substantially perpendicular to the vertical direction and the machining feed direction.

[0035] When the stepped portion 1a is to be formed on the composite substrate 1, first, a portion of the peripheral edges of the support plate 3 (a portion corresponding to one side of a rectangle in plan view) to be machined (removed) is adjusted substantially parallel to the machining feed direction by rotating the chuck table 4 holding the composite substrate 1. Next, the cutting blade 18 is positioned above an extension of the portion of the peripheral edges as described above by moving the chuck table 4 and the cutting unit 14 relative to each other.

[0036] In addition, a lower end of the cutting blade 18 is positioned at a position lower than the first surface 3a of the support plate 3 and slightly higher than an interface between the provisional bonding layer 5 and the workpiece 7. Thereafter, the chuck table 4 is moved in the machining feed direction while rotating the cutting blade 18. As shown in Fig. 2A, it is thereby possible to have the cutting blade 18 cut along a part of the peripheral edges of the support plate 3 from the side of the second surface 3b and consequently to remove a part of a peripheral portion of the support plate 3 including the part of the peripheral edges.

[0037] In the present embodiment, as described above, the cutting blade 18 is configured to cut to a depth reaching the first surface 3a of the support plate 3. Therefore, the step portion 1a is formed on a part of the peripheral portion of the composite substrate 1 in a stepped shape such that a peripheral portion 7b of the workpiece protrudes laterally (outward in a direction parallel to the first surface 3a or the second surface 3b) compared to the peripheral portion 3c of the support plate 3 after machining.

[0038] An overlap width of the support plate 3 (peripheral portion) and the cutting blade 18 (ie, the width of the removed peripheral portion in the support plate 3 or a protrusion amount of the peripheral portion 7b of the workpiece 7) is set in a range where the step portion 1a has a size suitable for applying a force. Considering an actual width of the cutting blade 18 and the like, the overlap width is preferably set to, for example, 0.2 mm to 5 mm.

[0039] After the step portion 1a is formed on a part of the peripheral portion of the composite substrate 1 by removing a part of the peripheral portion of the support plate 3 by the method described above, the step portion 1a is also formed on another part of the peripheral portion of the composite substrate 1 by removing another part of the peripheral portion of the support plate 3 by a similar method. The step portion forming step is completed when the entire peripheral portion of the support plate 3 is removed, and the step portion 1a is formed on the entire peripheral portion of the composite substrate 1. Fig. 2B is a sectional view showing a state in which the step portion 1a is formed on the entire peripheral portion of the composite substrate 1.

[0040] It should be noted that the step portion 1a in the present embodiment, as shown in Fig. 2B, although the step portion 1a is formed on the entire peripheral portion of the composite substrate 1, it is sufficient to form the step portion 1a at least on an optional part of the peripheral portion of the composite substrate 1. In this case, the shape of the step portion 1a (shape as viewed from the support plate 3 side) or the like can also be optionally determined. In addition, in a case where the support plate and the workpiece constituting the composite substrate are circular (i.e., disk-shaped) in plan view, the step portion can be formed on the composite substrate by rotating the chuck table 4 while causing the cutting blade 18, for example, to cut into the peripheral portion of the support plate. Of course, even in this case, the step portion could be formed by cutting away only an optional part of the peripheral portion of the support plate.

[0041] After the step portion forming step, the carrier plate holding step is performed, which holds the carrier plate 3 side of the composite substrate 1. Fig. 3A is a sectional view showing the carrier plate holding step. The carrier plate holding step is carried out using a Fig. 3A and the like. The peeling device 22 has a carrier plate holding unit 24 for holding the carrier plate 3 side of the composite substrate 1 from above.

[0042] At a lower portion of the support plate holding unit 24, a holding surface 24a is formed, which has a size similar to the second surface 3b of the support plate 3. A suction source (not shown) is connected to the holding surface 24a via a flow line (not shown), a valve (not shown), and the like. Therefore, when the valve is opened, negative pressure from the suction source can be applied to the holding surface 24a. In addition, the support plate holding unit 24 is supported by a lifting and lowering mechanism (not shown) and thus moved in the vertical direction.

[0043] In the carrier plate holding step, as used for example in Fig. As shown in FIG. 3A, the holding surface 24a of the support plate holding unit 24 is brought into contact with the second surface 3b of the support plate 3 in a state where the support plate 3 is arranged above the workpiece 7. Then, the valve is opened to cause a negative pressure of the suction source to act on the holding surface 24a. Thereby, the support plate 3 side of the composite substrate 1 is held from above by the support plate holding unit 24.

[0044] After the carrier plate holding step, the removal step is carried out in which the carrier plate 3 is removed from the workpiece 7. Fig. Figure 3B is a sectional view showing the removal step. Fig. 3C is a sectional view showing a state in which the support plate 3 is removed from the workpiece 7. The removal step is performed by further using the puller 22.

[0045] As in Fig. 3B, a rod-shaped external force applying member 26 (pressure member) having a downwardly directed distal end is disposed on one side of the support plate holding unit 24 at a position corresponding to the step portion 1a of the composite substrate 1 held by the support plate holding unit 24. The external force applying member 26 is supported, for example, by a lifting and lowering mechanism (not shown) different from the lifting and lowering mechanism that moves the support plate holding unit 24. The external force applying member 26 is thus moved in the vertical direction independently of the support plate holding unit 24.

[0046] In the removal step, first, the composite substrate 1 held by the support plate holding unit 24 is lifted by moving both the support plate holding unit 24 and the external force application member 26 upward. That is, the first surface 7a side of the workpiece 7 is exposed downward. Next, the external force application member 26 is moved downward while maintaining the position of the support plate holding unit 24, and the distal end (lower end) of the external force application member 26 is brought into contact with a part of the step portion 1a located on the workpiece 7 side (the peripheral portion 7b of the workpiece 7) from above. Thereby, a downward force is applied from the external force application member 26 to the step portion 1a of the composite substrate 1.

[0047] As described above, the support plate 3 side of the composite substrate 1 is held by the support plate holding unit 24 from above. Therefore, when the downward force is applied from the external force applying member 26 to the part of the step portion 1a located on the workpiece 7 side, the workpiece 7 is peeled off from the support plate 3 with the provisional bonding layer 5 as a boundary and falls. That is, the workpiece 7 moves in a direction of separating from the support plate 3. The removal step is completed when the entire workpiece 7 is separated from the support plate 3 and the support plate 3 is removed from the workpiece 7.

[0048] As described above, in the carrier plate removal method according to the present embodiment, the step portion 1a in which the workpiece 7 protrudes laterally compared to the carrier plate 3 is formed by machining the carrier plate 3 so that the peripheral portion of the carrier plate 3 along the peripheral edge of the carrier plate 3 is removed from the second surface (lower surface) 3b side of the carrier plate 3. Thus, in a state where the carrier plate 3 is held by the carrier plate holding unit 24 from above, the carrier plate 3 can be easily removed from the workpiece 7 by applying a downward force to the step portion 1a.

[0049] In addition, in the carrier plate removing method according to the present embodiment, it is sufficient to machine only the side of the carrier plate 3, and therefore the carrier plate 3 can be removed from the workpiece 7 without machining the side of the workpiece 7.

[0050] It should be noted that the present invention is not limited to the description of the foregoing embodiment, but can be modified and implemented in various ways. For example, while the external force application member 26 in the foregoing embodiment is configured to be movable in the vertical direction independently of the support plate holding unit 24, it is sufficient if the external force application member 26 can be moved at least relative to the support plate holding unit 24.

[0051] For example, the external force applying member 26 could be moved relative to the carrier plate holding unit 24 by attaching the external force applying member 26 to a housing (not shown) of the puller 22 or the like and moving only the carrier plate holding unit 24. Additionally, although one external force applying member 26 is used in the above embodiment, multiple external force applying members 26 may be used.

[0052] Additionally, in the above embodiment, the step portion 1a is formed on the composite substrate 1 by causing the cutting blade 18 to cut into the support plate 3 along the peripheral edge of the support plate 3 from the second surface (bottom surface) 3b side of the support plate 3, thereby removing the peripheral portion of the support plate 3. However, the step portion 1a could be formed on the composite substrate 1, for example, by irradiating the support plate 3 with a laser beam along the peripheral edge of the support plate 3 from the second surface 3b side of the support plate 3, thereby removing the peripheral portion of the support plate 3.

[0053] In this case, it is advantageous to subject the support plate 3 to ablation processing with a laser beam by using a laser processing device (laser processing unit) that can apply a laser beam with a wavelength absorbed by the support plate 3, for example, instead of the cutting device 2 (cutting unit 14). In addition, the support plate 3 could be modified by the laser beam by using a laser processing device (laser processing unit) that can apply a laser beam with a wavelength that passes through the support plate 3, for example. After the support plate 3 is modified by the laser beam, the step portion can be formed by applying a force to a modified area and removing this area.

[0054] In addition, while the step portion 1a is formed on the composite substrate 1 without removing the peripheral portion 7b of the workpiece 7 in the foregoing embodiment, the peripheral portion 7b of the workpiece 7 may be removed depending on machining accuracy when removing the peripheral portion of the support plate 3. Therefore, the peripheral portion 7b of the workpiece 7 may be removed in a region where the step portion 1a is obtained if there appears to be no problem with the quality of the workpiece 7.

[0055] In addition, when the carrier plate 3 is removed in the removing step, a fluid may be sprayed between the carrier plate 3 and the workpiece 7 (area corresponding to the provisional bonding layer 5). Fig. 4A is a sectional view showing a removal step according to a first modification. As shown in Fig. As shown in FIG. 4A, a nozzle 32 is arranged on one side of the carrier plate holding unit 24 of the peeling device 22 used in the first modification. A supply source (not shown) of a fluid 34 is connected to the nozzle 32 via a flow line (not shown), a valve (not shown), and the like.

[0056] The workpiece 7 can be more easily peeled off from the support plate 3 by applying a downward force to the step portion 1a by the external force applying member 26 after the fluid 34 is sprayed from the nozzle 32 between the support plate 3 and the workpiece 7 or while the fluid 34 is sprayed from the nozzle 32 between the support plate 3 and the workpiece 7. For example, air, water, or the like can be used as the fluid 34 sprayed between the support plate 3 and the workpiece 7. However, the type and the like of the fluid 34 are not particularly limited.

[0057] In addition, the carrier plate 3 and the workpiece 7 could be immersed in a liquid when the carrier plate 3 is removed in the removal step. Fig. 4B is a sectional view showing a removal step according to a second modification. As shown in Fig. As shown in Fig. 4B, a tank 42 sized to accommodate the support plate 3 and the workpiece 7 is disposed below the support plate holding unit 24 of the pull-off device 22 used in the second modification. A liquid 44 such as water is stored in the tank 42.

[0058] When the workpiece 7 is peeled off from the support plate 3 by applying a downward force to the step portion 1a by the external force applying member 26 in a state where the support plate 3 and the workpiece 7 are immersed in the liquid 44 inside the tank 42, the peeled workpiece 7 falls into the liquid 44. Consequently, an impact accompanying the fall is reduced compared to a case where the workpiece 7 falls in the air, so that damage to the workpiece 7, vibration of the peeling device 22, and the like can be prevented.

[0059] Meanwhile, the liquid 44 may contain a surfactant. An anionic surfactant, a cationic surfactant, or the like that easily penetrates the temporary bonding layer 5 may be used as the surfactant contained in the liquid 44. When the surfactant that easily penetrates the temporary bonding layer 5 is contained in the liquid 44, the temporary bonding layer 5 can be easily separated from a region into which the surfactant penetrates, and thus the workpiece 7 can be more easily peeled off the support plate 3.

[0060] Additionally, in the second modification, a vibration such as an ultrasonic wave may be applied to the external force applying member 26 when the external force applying member 26 applies a downward force to the step portion 1a after the support plate 3 and the workpiece 7 are immersed in the liquid 44. Specifically, the external force applying member 26 applies a downward force to the step portion 1a while a vibration such as an ultrasonic wave is applied to the external force applying member 26. In this case, the workpiece 7 can be more easily peeled off from the support plate 3 due to the effect of the vibration transmitted from the external force applying member 26.

[0061] Similarly, a vibration such as an ultrasonic wave could be applied to the liquid 44 when the external force applying member 26 applies a downward force to the step portion 1a after the support plate 3 and the workpiece 7 are immersed in the liquid 44. Specifically, the external force applying member 26 applies a downward force to the step portion 1a while applying a vibration such as an ultrasonic wave to the liquid 44. In this case, the workpiece 7 can be more easily peeled off the support plate 3 due to the effect of the vibration transmitted by the liquid 44.

[0062] In addition, after the carrier plate holding step is performed, before the removing step is performed, a workpiece holding step may be performed in which the workpiece 7 side of the composite substrate 1 is held by a holding unit. Fig. 5A is a sectional view showing the platen holding step and the workpiece holding step according to a third modification. Fig. 5B is a sectional view showing a state in which the external force applying member 26 is brought into contact with the step portion 1a in the removing step in the third modification. Fig. 5C is a sectional view showing a state in which the platen holding unit 24 is moved upward relative to the external force applying member 26 and the workpiece holding unit (holding table) 52 in the removing step in the third modification.

[0063] In the third modification, as in Fig. As shown in Fig. 5A, the support plate 3 side of the composite substrate 1 is held by the support plate holding unit 24 from above in the support plate holding step, and thereafter, the workpiece holding step is performed, which holds (supports) the workpiece 7 by a holding surface (upper surface) 52a of a workpiece holding unit 52. Specifically, the workpiece holding unit 52 is positioned below the support plate holding unit 24 that holds the composite substrate 1, then the support plate holding unit 24 is lowered, and the first surface 7a of the workpiece 7 is brought into contact with the holding surface 52a of the workpiece holding unit 52.

[0064] In the following removal step, in a state where the external force applying member 26 is in contact with the step portion 1a from the side of the support plate 3, as shown in Fig. 5B, the carrier plate holding unit 24 is moved upward relative to the external force applying element 26 and the workpiece holding unit 52, as shown in Fig. 5C. This makes it possible to pull the workpiece 7 off the support plate 3 by applying a downward force to the step portion 1a and to remove the support plate 3 from the workpiece 7.

[0065] In the third modification, the workpiece holding unit 52 firmly holds the workpiece 7 from below. Thus, even when the workpiece 7 is pulled off the support plate 3, the peeled workpiece 7 does not fall due to gravity. That is, the impact associated with the fall becomes zero. It is thus possible to reliably prevent damage to the workpiece 7, vibration of the peeling device 22, and the like.

[0066] In addition, the carrier plate removing method according to the present invention could be performed using a peeling device having a different structure than that of the peeling device 22 described above. Fig. 6A is a sectional view showing a state in which the external force applying member 26 is brought into contact with the step portion 1a in a removing step in a fourth modification, the step being performed by using a peeler having a different structure from that of the peeler 22. Fig. 6B is a sectional view showing a state in which a region (starting point region) 5c serving as a starting point at a time of peeling the workpiece 7 from the support plate 3 in the removing step in the fourth modification is formed in the provisional bonding layer 5. Fig. 6C is a sectional view showing a state in which the workpiece 7 is peeled off from the support plate 3 in the removing step in the fourth modification.

[0067] A basic procedure of a carrier plate removal method according to the fourth modification is similar to the carrier plate removal method according to the third modification. That is, the fourth modification includes the workpiece holding step in addition to the step portion forming step, the carrier plate holding step, and the removal step. However, the fourth modification uses a pull-out device 62 having a different structure from that of the pull-out device 22. Hereinafter, components common to the pull-out device 22 and the pull-out device 62 are denoted by the same reference numerals, and the different components will be mainly described.

[0068] As in Fig. 6A or the like, the peeling device 62 according to the fourth modification includes a base plate (carrier plate holding unit) 64. A reference surface 64a, which has a similar size to the second surface 3b of the carrier plate 3, is formed on a lower portion of the base plate 64. The reference surface 64a is curved, for example, so that an outer portion thereof is located above an inner portion thereof. That is, the reference surface 64a is formed by a downwardly projecting curved surface.

[0069] A suction source (not shown) is connected to a central portion of the reference surface 64a via a first flow line 64b, a first valve (not shown), and the like. In addition, a suction source is connected to the outer portion of the reference surface 64a via a second flow line 64c, a second valve (not shown), and the like. An annular sealing member 66 is disposed at a peripheral portion of the reference surface 64a, substantially enclosing the entire reference surface 64a. The sealing member 66 is, for example, an O-ring formed of a material such as rubber having a predetermined elasticity. The sealing member 66 is suitable for ensuring airtightness.

[0070] A flexible plate (support plate holding unit) 68, which has flexibility, is arranged on the reference surface 64a side of the base plate 64. The flexible plate 68 has a frame 70 that is substantially flat in a state where no external force is applied. A depressed portion 70a is formed on the lower surface side of the frame 70. A porous plate 72 is attached to the depressed portion 70a.

[0071] The flexible plate 68 is connected to the base plate 64 such that a central portion of the upper surface of the frame 70 contacts a central portion of the reference surface 64a, and a peripheral portion of the upper surface of the frame 70 contacts the closure member 66. That is, in a state in which no external force is applied to the flexible plate 68, a clearance is formed between the outer portion of the reference surface 64a and the peripheral portion of the upper surface of the frame 70, as shown in Fig. 6A.

[0072] A through-hole 70b is formed in the central region of the upper surface of the frame 70, which is connected to the first flow passage 64b. Therefore, when the first valve is opened, negative pressure from the intake source can be caused to act on a lower surface 72a of the plate 72 through the first flow passage 64b and the through-hole 70b. On the other hand, when the second valve is opened, air located in the space between the outer region of the reference surface 64a and the peripheral portion of the upper surface of the frame 70 (space surrounded by the closure member 66) is discharged through the second flow passage 64c. As a result, the space between the outer region of the reference surface 64a and the peripheral portion of the upper surface of the frame 70 is decompressed, the closure member 66 is deformed, and the flexible plate 68 is curved along the reference surface 64a.

[0073] In the fourth modification, as in Fig. As shown in Fig. 6A, the workpiece holding step of holding the workpiece 7 by the holding surface 52a of the workpiece holding unit 52 is performed after the support plate holding step of holding the support plate 3 side of the composite substrate 1. In the support plate holding step, the lower surface 72a of the flexible plate 68 is brought into contact with the second surface 3b of the support plate 3. Then, the first valve is opened to cause a negative pressure of the suction source to act on the lower surface 72a. Thereby, the support plate 3 side of the composite substrate 1 is held from above by the base plate 64 and the flexible plate 68.

[0074] In the workpiece holding step, for example, the workpiece holding unit 52 is positioned below the base plate 64 and the flexible plate 68 that hold the composite substrate 1, then the base plate 64 and the flexible plate 68 are lowered, and the first surface 7a of the workpiece 7 is brought into contact with the holding surface 52a of the workpiece holding unit 52.

[0075] In the following removal step, as in Fig. 6B, first, the first valve is opened to decompress the clearance between the outer region of the reference surface 64a and the peripheral portion of the upper surface of the frame 70 in a state where the external force application member 26 is in contact with the step portion 1a of the support plate 3 side. The flexible plate 68 is thereby curved along the reference surface 64a in a state where the support plate 3 side of the composite substrate 1 is held. That is, an upward force that curves the support plate 3 side acts on the peripheral portion 3c of the support plate 3.

[0076] On the other hand, the external force application member 26 is in contact with the side of the workpiece 7 (peripheral portion 7b) of the step portion 1a, and therefore the workpiece 7, unlike the support plate 3, is not curved. Consequently, as shown in Fig. 6C, the peripheral portion 3c of the support plate 3 is curved in a direction in which it separates from the workpiece 7, and an end portion of the provisional bonding layer 5 can be divided into a first part 5a on the side of the support plate 3 and a second part 5b on the side of the workpiece 7. A region 5c at the end portion of the provisional bonding layer 5 divided into the first part 5a and the second part 5b serves as a starting point at the time of peeling the support plate 3 from the workpiece 7.

[0077] After the area 5c is formed as in Fig. As shown in Fig. 6C, the base plate 64 and the flexible plate 68 are moved upward relative to the external force applying member 26 and the workpiece holding unit 52. This makes it possible to peel the workpiece 7 from the support plate 3 with the area 5c as a starting point by applying a downward force to the step portion 1a, and to remove the support plate 3 from the workpiece 7.

[0078] In the fourth embodiment, the workpiece holding unit 52 firmly holds the workpiece 7 from below. Thus, the peeled workpiece 7 does not fall due to gravity even when peeling from the support plate 3. That is, the impact associated with the fall becomes zero. Therefore, it is possible to more reliably prevent damage to the workpiece 7, vibration of the peeling device 22, and the like.

[0079] Additionally, in the fourth modification, a region (starting point region) 5c serving as a starting point at the time of removing the support plate 3 from the workpiece 7 is formed in the provisional bonding layer 5 by curving the peripheral portion 3c of the support plate 3 in a direction away from the workpiece 7. Therefore, the workpiece 7 can be easily peeled off from the support plate 3 with little force.

[0080] Furthermore, in the above-described embodiment and each of the modifications, a mode was described in which the support plate holding unit holds the support plate 3 side of the composite substrate 1 from above, or the workpiece holding unit holds the workpiece 7 side of the composite substrate 1 from below. However, a relationship between directions (for example, top and bottom) specified in the embodiment and each modification may be interchanged.

[0081] Specifically, for example, the support plate holding unit may hold the support plate 3 side of the composite substrate 1 from below, or the workpiece holding unit may hold the workpiece 7 side of the composite substrate 1 from above. In this case, however, the external force application member is brought into contact with the step portion 1a from below.

[0082] Fig. 7A is a sectional view showing a workpiece holding step in a fifth modification. Fig. 7B is a sectional view illustrating a state in which a region (starting point region) 5c serving as a starting point at the time of peeling off the workpiece 7 from the support plate 3 in a removing step in the fifth modification is formed in the provisional bonding layer 5. Fig. 7C is a sectional view showing a state in which the workpiece 7 is peeled off from the support plate 3 in the removing step in the fifth modification.

[0083] In a carrier plate removal method according to the fifth modification, the workpiece holding step is performed after a step portion forming step. In addition, a carrier plate holding step and the removal step are performed after the workpiece holding step. Meanwhile, in the fifth modification, the carrier plate holding step is performed while the removal step is performed.

[0084] As in Fig. 7A and the like, the fifth modification uses a peeling device 82 having a different structure from the peeling device 22 and the peeling device 62. The peeling device 82 includes a workpiece holding unit 84 for holding the workpiece 7 side of the composite substrate 1 from above. At a lower portion of the workpiece holding unit 84, a holding surface 84a is formed that is smaller than the first surface 7a of the workpiece 7.

[0085] A suction source (not shown) is connected to the holding surface 84a via a flow line (not shown), a valve (not shown), and the like. Therefore, when the valve is open, negative pressure from the suction source can act on the holding surface 84a. In addition, the workpiece holding unit 84 is supported by a lifting and lowering mechanism (not shown) and is thereby moved in the vertical direction.

[0086] A support plate support unit 86 is arranged below the workpiece support unit 84. A support surface 86a is formed on an upper portion of the support plate support unit 86, which has a similar size to the second surface 3b of the support plate 3. A suction source (not shown) is connected to the support surface 86a via a flow line (not shown), a valve (not shown), and the like. Therefore, when the valve is open, negative pressure from the suction source can act on the support surface 86a.

[0087] On one side of the base plate holding unit 86, a rod-shaped external force applying member 88 (pressure member) with an upwardly directed distal end is arranged at a position corresponding to the step portion 1a of the composite substrate 1 held by the base plate holding unit 86. The external force applying member 88 is fixed, for example, to the housing (not shown) of the peeling device 22, the base plate holding unit 86, or the like. Therefore, a positional relationship between the base plate holding unit 86 and the external force applying member 88 does not change.

[0088] In addition, the height of the distal end (upper end) of the external force application member 88 is adjusted so that the peripheral portion 7b of the workpiece 7, which constitutes the step portion 1a, can be pushed upward when the support plate 3 is brought into contact with the holding surface 86a of the support plate holding unit 86. That is, a height difference between the holding surface 86a of the support plate holding unit 86 and the distal end of the external force application member 88 is greater than a sum of the thickness of the support plate 3 and the thickness of the provisional bonding layer 5.

[0089] In the workpiece holding step, as in Fig. 7A, the holding surface 84a of the workpiece holding unit 84 is brought into contact with the first surface 7a of the workpiece 7 in a state where the workpiece 7 is arranged, for example, above the support plate 3. Then, the valve is opened, so that a negative pressure from the suction source acts on the holding surface 84a. As a result, the workpiece 7 side of the composite substrate 1 is held from above by the workpiece holding unit 84.

[0090] After the workpiece holding step, the carrier plate holding step of holding the carrier plate 3 by the carrier plate holding unit 86 and the removal step of removing the carrier plate 3 from the workpiece 7 are performed. Specifically, for example, as shown in Fig. 7B, the workpiece holding unit 84 holding the workpiece 7 side of the composite substrate 1 is lowered, and the second surface 3b of the support plate 3 is brought into contact with the holding surface 86a of the support plate holding unit 86.

[0091] As described above, the height difference between the holding surface 86a of the base plate holding unit 86 and the distal end of the external force applying member 88 is larger than the sum of the thickness of the base plate 3 and the thickness of the provisional bonding layer 5. Therefore, when the workpiece holding unit 84 is lowered, the distal end of the external force applying member 88 comes into contact with the step portion 1a (peripheral portion 7b) before the second surface 3b of the base plate 3 comes into contact with the holding surface 86a of the base plate holding unit 86.

[0092] Therefore, when the workpiece holding unit 84 is further lowered from this state, an upward force is applied to the step portion 1a (peripheral portion 7b) by the external force applying member 88. As a result, as shown in Fig. 7B, the peripheral portion 7b of the workpiece 7 is curved in a direction of separation from the support plate 3, and an end portion of the provisional bonding layer 5 can be cut into a first part 5a on the side of the support plate 3 (see Fig. 7C) and a second part 5b on the side of the workpiece 7 (see Fig. 7C). A region 5c at the end portion of the provisional bonding layer 5, divided into the first part 5a and the second part 5b, serves as a peeling starting point at the time of peeling the carrier plate 3 from the workpiece 7.

[0093] After the area 5c is formed as in Fig. 7B, the support plate holding unit 86 is made to hold the support plate 3 side of the composite substrate 1 by applying a negative pressure of the suction source to the holding surface 86a in a state where the second surface 3b of the support plate 3 is in contact with the holding surface 86a. Thereafter, as shown in Fig. 7C, the workpiece holding unit 84 is lifted. This pulls the workpiece 7 from the support plate 3 with the area 5c as the starting point. That is, the support plate 3 can be removed from the workpiece 7 by moving the workpiece 7 in a direction in which it separates from the support plate 3.

[0094] In the fifth modification, the region (starting point region) 5c, which serves as a starting point for removing the support plate 3 from the workpiece 7, is formed in the temporary bonding layer 5 by curving the peripheral portion 7b of the workpiece 7 in a direction of separation from the support plate 3. Therefore, the workpiece 7 can be easily peeled off from the support plate 3 with little effort.

[0095] The above-described embodiment and the modifications can be arbitrarily combined with each other. For example, the first modification may be further combined with the second modification. In this case, a fluid is sprayed between the support plate 3 and the workpiece 7 (in a region corresponding to the temporary bonding layer 5) after the support plate 3 and the workpiece 7 are immersed in the liquid 44. That is, the workpiece 7 is peeled off from the support plate 3 by the external force applying member 26 applying a downward force to the step portion 1a after the fluid 34 is sprayed between the support plate 3 and the workpiece 7 or while the fluid 34 is sprayed between the support plate 3 and the workpiece 7.

Claims

[1] A carrier plate removal method for removing a carrier plate (3) from a workpiece (7) arranged on an upper surface (3a) of the carrier plate (3) via a temporary bonding layer (5), the carrier plate removal method comprising: a step portion forming step of forming a step portion (1a) in which the workpiece (7) protrudes laterally compared to the support plate (3) by machining the support plate (3) to remove a peripheral portion (3c) of the support plate (3) along a peripheral edge of the support plate (3) from a side of the lower surface (3a) opposite to the upper surface (3a) of the support plate (3); a carrier plate holding step of holding the carrier plate (3) by a carrier plate holding unit (24) after performing the step portion forming step; and a removing step of removing the support plate (3) from the workpiece (7) by applying a force from the side of the support plate (3) to the step portion (1a) and moving the workpiece (7) in a direction of separation from the support plate (3) after performing the step portion forming step. [2] The carrier plate removing method according to claim 1, wherein in the removal step, the workpiece (7) is moved in the direction of separation from the carrier plate (3) by the force applied to the step portion (1a). [3] The carrier plate removing method according to claim 1 or 2, further comprising: a workpiece holding step of holding the workpiece (7) by a workpiece holding unit (52) before performing the removing step. [4] The carrier plate removing method according to claim 3, wherein in the removing step, the carrier plate (3) is removed from the workpiece (7) by applying the force to the step portion (1a) by moving the carrier plate holding unit (24) relative to the workpiece holding unit (52) and an external force applying member (26) in a state where the external force applying member (26) is held in contact with the step portion (1a) from the carrier plate (3) side. [5] The carrier plate removing method according to claim 4, wherein in the removing step, a starting point region (5c) serving as a starting point at a time of removing the carrier plate (3) from the workpiece (7) is formed in the provisional bonding layer (5) by curving the peripheral portion (3c) of the carrier plate (3) in a direction of separation from the workpiece (7) before moving the carrier plate holding unit (24) relative to the workpiece holding unit (52) and the external force applying member (26). [6] The base plate removing method according to any one of the preceding claims, wherein in the removing step, the workpiece (7) is moved in the direction of separating from the base plate (3) after a start point region (5c) serving as a start point at a time of removing the base plate (3) from the workpiece (7) is formed in the provisional bonding layer (5) by curving a peripheral portion (7b) of the workpiece (7) in the direction of separating from the base plate (3) by the force applied to the step portion (1a). [7] A carrier plate removing method according to any one of the preceding claims, wherein in the removing step, the carrier plate (3) is removed from the workpiece (7) by applying the force to the step portion (1a) after a fluid (34) is sprayed between the workpiece (7) and the carrier plate (3) or while the fluid (34) is sprayed between the workpiece (7) and the carrier plate (3). [8] A carrier plate removing method according to any one of the preceding claims, wherein in the removing step, the carrier plate (3) is removed from the workpiece (7) by applying the force to the step portion (1a) in a state where the workpiece (7) and the carrier plate (3) are immersed in a liquid (44). [9] The carrier plate removing method according to claim 8, wherein in the removing step, the carrier plate (3) is removed from the workpiece (7) by applying the force to the step portion (1a) by pressing an external force applying member (26) to which vibration is applied against the step portion (1a) in a state where the workpiece (7) and the carrier plate (3) are immersed in the liquid (44). [10] The carrier plate removing method according to claim 8 or 9, wherein in the removing step, the carrier plate (3) is removed from the workpiece (7) by applying the force to the step portion (1a), in a state where the workpiece (7) and the carrier plate (3) are immersed in the liquid (44), a vibration is applied to the liquid (44). [11] A carrier plate removal method according to any one of claims 8 to 10, wherein the liquid (44) includes a surfactant.

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