Method for peeling object from adhesive sheet

Abstract

The invention provides an adhesive sheet which is easier to peel an element. The adhesive sheet is provided with an adhesive layer having concaves and convexes on the surface, and the adhesive sheet can extend in the surface direction, so that the surface release force of an object on the adhesive sheet after extension is lower than the surface release force of an object on the adhesive sheet before extension.

Description

Technical Field

[0001] The present invention relates to a method for peeling an object from an adhesive sheet. Background Art

[0002] Adhesive sheets for temporarily holding objects are known. Such adhesive sheets can be used to transfer objects to a desired location.

[0003] PSA sheets have various shapes depending on their uses. For example, Patent Document 1 discloses a technology that can firmly adhere a functional PSA sheet to an adherend and also temporarily adhere the PSA sheet.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2004-115766 Summary of the invention

[0007] Problems to be solved by the invention

[0008] When transferring an object from an adhesive sheet, in order to promote peeling, an external stimulus is applied to the substrate to pick up the object. The external stimulus is, for example, a push by a needle or energy imparted by ultraviolet rays, etc., which has the following problem: damage to the object or the adhesive sheet accumulates as the process proceeds.

[0009] An object of the present invention is to provide a pressure-sensitive adhesive sheet that makes it easier to peel an object.

[0010] Solutions for solving problems

[0011] The inventors of the present invention have repeatedly conducted in-depth research and found that they can provide the following adhesive sheet to solve the above-mentioned problems. The inventors of the present invention have repeatedly conducted various studies to complete the present invention. The adhesive sheet has an adhesive layer with a concave-convex surface and can be extended along the surface direction. The surface peeling force of an object on the adhesive sheet after extension is lower than the surface peeling force of an object on the adhesive sheet before extension, thereby making it easier to peel off the object.

[0012] That is, the present invention relates to the following [1] to

[11] .

[0013] [1] A method for peeling an object from an adhesive sheet, the method comprising:

[0014] an extending step of extending the adhesive sheet having an adhesive layer with irregularities on the surface and holding an object on the adhesive layer in a surface direction; and

[0015] The peeling step is to peel the object from the adhesive layer of the adhesive sheet after the adhesive layer is extended in the surface direction.

[0016] [2] The peeling method according to [1], wherein the object after peeling is transferred to a transfer destination different from the pressure-sensitive adhesive sheet.

[0017] [3] The peeling method according to [2], wherein the peeling step is performed by bringing the object held by the adhesive sheet extended in the surface direction into contact with the transfer destination, and pulling the transfer destination away from the adhesive sheet without applying an external stimulus to the adhesive sheet.

[0018] [4] The peeling method according to any one of [1] to [3], wherein the pressure-sensitive adhesive sheet further comprises a substrate for supporting the pressure-sensitive adhesive layer.

[0019] The tensile modulus of the substrate is 2500 MPa or less.

[0020] [5] The pressure-sensitive adhesive sheet according to [4], wherein the substrate has an elongation at break of 105% or more.

[0021] [6] The peeling method according to [4], wherein the substrate is a polyolefin film or a vinyl chloride copolymer film.

[0022] [7] The peeling method according to any one of [1] to [6], wherein in the stretching step, the pressure-sensitive adhesive sheet is stretched by 1% or more in the surface direction.

[0023] [8] The peeling method according to any one of [1] to [7], wherein the adhesive layer has a plurality of convex portions which are bounded by concave portions and are spaced apart from each other,

[0024] A pitch of the plurality of protrusions in the adhesive sheet before the stretching is greater than or equal to 1 μm and less than or equal to 100 μm.

[0025] [9] The pressure-sensitive adhesive sheet according to [8], wherein a pitch of the protrusions after stretching in the pressure-sensitive adhesive sheet is 1.05 times or more the pitch of the protrusions before stretching.

[0026]

[10] The peeling method according to any one of [1] to [9], wherein in the extending step, the inner side of the peripheral portion of the adhesive sheet is displaced in the thickness direction of the adhesive sheet while the peripheral portion of the adhesive sheet is fixed, thereby extending the adhesive sheet.

[0027]

[11] The peeling method according to any one of [1] to

[10] , wherein the adhesive layer is formed from an adhesive composition containing an energy ray-curable compound.

[0028]

[12] The peeling method according to any one of [1] to

[11] , wherein the shear storage modulus of the adhesive layer is 0.001 MPa or more and 100 MPa or less.

[0029] Effects of the Invention

[0030] The present invention provides a pressure-sensitive adhesive sheet that makes it easier to peel an object.

[0031] Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings. In addition, in the accompanying drawings, the same reference numerals are used for the same or similar structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are incorporated in and constitute a part of the specification, illustrate embodiments of the present invention, and together with the description, serve to explain the principles of the present invention.

[0033] Figure 1 This is a schematic diagram of a pressure-sensitive adhesive sheet according to one embodiment.

[0034] Figure 2A This is a side view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0035] Figure 2B This is a side view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0036] Figure 3A This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0037] Figure 3B This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0038] Figure 3C This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0039] Figure 4A This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0040] Figure 4B This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0041] Figure 4C This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0042] Figure 5 This is a schematic diagram for explaining the adhesive layer and the release layer.

[0043] Figure 6 This is a flowchart of a method for manufacturing an electronic component or a semiconductor device according to one embodiment.

[0044] Fig. 7A This is a schematic diagram for explaining separation and capture of components.

[0045] Figure 7B This is a schematic diagram for explaining separation and capture of components.

[0046] Fig. 8A This is a schematic diagram for explaining the extension of the pressure-sensitive adhesive sheet.

[0047] Figure 8B This is a schematic diagram for explaining the extension of the pressure-sensitive adhesive sheet. DETAILED DESCRIPTION

[0048] Hereinafter, the embodiments are described in detail with reference to the accompanying drawings. It should be noted that the following embodiments do not limit the invention of the patent application scope, and the combination of features described in the embodiments is not necessarily required for the invention. Two or more of the multiple features described in the embodiments can be combined arbitrarily. In addition, the same reference number is marked for the same or identical configuration, and repeated description is omitted.

[0049] (definition)

[0050] In this specification, the mass average molecular weight (Mw) and the number average molecular weight (Mn) are values ​​measured by size exclusion chromatography in terms of standard polystyrene, specifically values ​​measured in accordance with JIS K7252-1: 2016. In addition, in this specification, "(meth)acrylic acid" refers to both "acrylic acid" and "methacrylic acid", and the same applies to other similar terms.

[0051] In this specification, "electronic parts" include all parts used in electronic engineering and electrical engineering, and all parts constituting electronic equipment. "Electronic parts" can be formed by any one of semiconductors, conductors and / or insulators or by a combination of them. As "electronic parts", for example, active parts (mainly formed by semiconductors, such as transistors, IC (Integrated Circuit), LSI (Large Scale Integration), super LSI, diodes, light-emitting diodes, thyristors, three-terminal regulators, and imaging elements, etc.), passive components (such as resistors, capacitors, speakers, coils, transformers, converters, relays, piezoelectric elements, crystal oscillators, ceramic resonators, and varistors, etc.), and structural parts (such as wiring parts, printed circuit boards, connectors, and switches, etc.). In addition, in this specification, "semiconductor devices" refer to all devices used in processors, memories, sensors, etc. that can function by utilizing semiconductor characteristics. As examples of "semiconductor devices", micro light-emitting diodes, mini light-emitting diodes, power devices, MEMS (Micro Electro Mechanical Systems, micro-electromechanical systems), and control chips can be cited.

[0052] In this specification, when one or more lower limits and one or more upper limits of a numerical range (such as a range of content, etc.) are recorded, it can be understood that any lower limit and upper limit and combination thereof are recorded. For example, the record of 1 or more, 2 or more, 3 or more and 9 or less, 8 or less, and 7 or less indicates that the numerical range can be any of 1 or more and 9 or less, 1 or more and 8 or less, 1 or more and 7 or less, 2 or more and 9 or less, 2 or more and 8 or less, 2 or more and 7 or less, 3 or more and 9 or less, 3 or more and 8 or less, and 3 or more and 7 or less.

[0053] The adhesive sheet of the present embodiment is provided with an adhesive layer having a concavoconvex surface, and can be extended in the face direction. The surface peeling force of the object of the adhesive sheet after extending in the face direction is lower than the surface peeling force of the object on the adhesive sheet before extending. Here, the surface peeling force refers to the adhesive force when picking up an object from the adhesive sheet, for example, measured in the embodiments described later. By reducing the surface peeling force, the peeling of the object becomes easy, and the object can be picked up without external stimulation such as stimulation or energy imparting using a needle or reducing the amount of external stimulation, thereby reducing the damage to each component. Below, the adhesive layer having a concavoconvex surface provided by the adhesive sheet of the present embodiment is described.

[0054] (Adhesive sheet)

[0055] The pressure-sensitive adhesive sheet of the present embodiment may include a pressure-sensitive adhesive layer that captures an object that is separated from the holding substrate, and a base material that supports the pressure-sensitive adhesive layer. Figure 1 A schematic diagram of an adhesive sheet according to this embodiment is shown. Figure 1 As shown, the adhesive sheet may include an adhesive layer 110 and a substrate 120. Of course, the adhesive sheet does not necessarily have to include the substrate 120. For example, the adhesive sheet may be composed only of the adhesive layer 110. In this case, an adhesive layer 110 with high support properties may be used. The following describes each structure of the adhesive sheet.

[0056] (Adhesive layer)

[0057] The adhesive layer 110 of this embodiment is an adhesive layer and may contain a resin. As described above, the surface of the adhesive layer 110 has concavoconvexity. It should be noted that the adhesive sheet may have two or more adhesive layers 110. For example, the adhesive sheet may have a laminate of one or more adhesive layers 110.

[0058] (Shear storage modulus)

[0059] From the viewpoint of the morphological stability of the concavo-convex shape on the adhesive layer surface, the shear storage modulus of the adhesive layer 110 is preferably more than 0.001MPa, more preferably more than 0.01MPa, more preferably more than 0.05MPa, more preferably more than 0.1MPa. On the other hand, in terms of the positional offset when the object can be suppressed, it is preferred that the shear storage modulus of the adhesive layer 110 is low. From this viewpoint, the shear storage modulus of the adhesive layer 110 is preferably less than 100MPa, more preferably less than 10MPa, more preferably less than 5MPa, more preferably less than 2MPa, more preferably less than 1MPa, more preferably less than 0.5MPa, more preferably less than 0.3MPa, more preferably less than 0.25MPa, more preferably less than 0.2MPa. In this specification, the shear storage modulus refers to the value measured by the method described in the embodiment.

[0060] (Surface peeling force before extension)

[0061] From the viewpoint of suppressing positional deviation when capturing an object, the surface peeling force of the adhesive layer 110 before extension is preferably 0.01N / 25mm or more, more preferably 0.1N / 25mm or more, further preferably 1.0N / 25mm or more, further preferably 2.0N / 25mm or more, and particularly preferably 3.0N / 25mm or more, and from the viewpoint of peeling the captured object from the adhesive layer 110 without damage, it is preferably 100N / 25mm or less, more preferably 10N / 25mm or less, and further preferably 5N / 25mm or less. In this specification, the surface peeling force refers to the value measured by the method described in the examples.

[0062] (Surface peeling force after extension)

[0063] From the viewpoint of suppressing the positional deviation before the object is peeled off, the surface peeling force of the adhesive layer 110 after extension is preferably 0.01N / 25mm or more, more preferably 0.1N / 25mm or more, further preferably 0.5N / 25mm or more, further preferably 1.0N / 25mm or more, and particularly preferably 1.5N / 25mm or more, and from the viewpoint of peeling the captured object from the adhesive layer 110 without damage, it is preferably 10N / 25mm or less, more preferably 5N / 25mm or less, and further preferably 3N / 25mm or less. In this specification, the surface peeling force after extension refers to the value measured by the method described in the examples.

[0064] (Adhesive layer extension step)

[0065] The adhesive sheet including the adhesive layer 110 of this embodiment can extend (expand) in the surface direction as described above. Figure 2A and Figure 2B ,as well as Figure 3A , Figure 3B and Figure 3C The example of the shape of the adhesive layer shown in the figure will be used to explain the step of extending the adhesive sheet of this embodiment in the surface direction. In addition, the stretching process of the adhesive sheet in the surface direction may be referred to as "(adhesive sheet) expansion" below.

[0066] The adhesive layer 110 of this embodiment has a surface with projections and depressions. In one embodiment, the adhesive layer 110 has a plurality of projections on its surface that are separated from each other by recesses and defined by boundaries. The plurality of projections may be separated by recesses that are continuous throughout the entire adhesive layer 110 .

[0067] Figure 2A and Figure 2B is a side view showing the shape of the adhesive layer 110, Figure 3A , Figure 3B as well as Figure 3C It is a plan view showing the shape of the adhesive layer 110 . Figure 2A and Figure 3A 1 shows an example of the adhesive layer 110 before extension, Figure 2B as well as Figure 3B 1 shows an example of the adhesive layer 110 after extension. Figure 2A as well as Figure 2B In the figure, the object supplemented by the protrusion of the adhesive layer 110, namely the element 140, on the other hand, Figure 3A , Figure 3B as well as Figure 3C The element 140 captured by the convex portion is omitted. In the following, various descriptions are made with the object captured by the adhesive sheet as the element 140, but the type of the object is not particularly limited thereto. The object may be, for example, a monolithic object such as a wafer, a panel, or a substrate, and the details will be described later.

[0068] Hereinafter, when simply expressed as a "convex portion" or a "concave portion", it refers to the convex portion or concave portion of the adhesive layer 110. Figure 2A as well as Figure 3A As shown, convex portions 111 are regularly arranged on the surface of the adhesive layer 110. Regular arrangement of the convex portions 111 means that the convex portions 111 are arranged on a straight line at a constant pitch P, and here, the convex portions 111 are arranged in a lattice shape.

[0069] In this embodiment, the adhesive sheet is extended. Figure 2A as well as Figure 3A The adhesive layer 210 is shown deformed into Figure 2B as well as Figure 3BThe adhesive layer 220 shown. If the adhesive layer 210 is compared with the adhesive layer 220, in the adhesive layer 220, the pitch P of each convex portion 111 is enlarged by extension, and the number of convex portions 111 that capture one substrate 230 is reduced. As a result, in the adhesive layer 220, the force of the convex portions 111 holding the substrate 230 is reduced compared to the adhesive layer 210, and the surface peeling force is also reduced. It should be noted that in this embodiment, the pitch P is fixed on the entire adhesive sheet, but the pitch P can also be made different, for example, the pitch P is reduced in a specified area of ​​the adhesive sheet.

[0070] It should be noted that Figure 3C is a top view showing other shapes of the adhesive layer 110. Figure 3C As shown in FIG. 1 , a stripe-shaped protrusion 111 may be provided on the surface of the adhesive layer 110. Figure 3C In the embodiment, linear protrusions 111 having a fixed width are arranged at fixed intervals. The width or interval of the linear protrusions 111 may be regularly varied, or the linear protrusions 111 may be irregularly arranged.

[0071] Below, refer to Fig. 8A and Figure 8B An example of the extension process is described. Fig. 8A and Figure 8B As shown, the base 310 is arranged in contact with the substrate 120 of the adhesive sheet 150, and the inner side of the peripheral portion is pulled down toward the base 310 while fixing the peripheral portion of the adhesive sheet 150. Fig. 8A The adhesive layer 210 and the substrate 120 are pressed against the base 310. As a result, Figure 8B As shown, the pressed part of the adhesive layer 210 is displaced in the thickness direction and deformed into an adhesive layer 220 with an enlarged pitch P. As described above, the "extension" process of this embodiment is a process of displacing the inner side of the fixed peripheral portion in the adhesive sheet in the thickness direction. The base 310 is, for example, a rectangular parallelepiped and is arranged outside the adhesive sheet. The base 310 can be, for example, arranged in a grid shape, or can be installed so that it can be moved to a position where an object is picked up.

[0072] The adhesive sheet can be extended to more than 1% in the surface direction by extension, for example. It is assumed that the expansion of the adhesive sheet of the present embodiment is carried out along the entire direction to illustrate, but the expansion of the adhesive sheet can be carried out in one direction, in two directions, or in multiple directions. The expansion of the surface direction of the adhesive sheet is evaluated, for example, by the enlargement rate of the pitch P generated by the extension. That is, the enlargement rate of the pitch P generated by the extension can be set to more than 1%, or more than 5%, or more than 10%, and can be set arbitrarily. Here, with respect to the viewpoint of reducing the surface peeling force, the pitch P after extension is preferably more than 1.05 times relative to the value before extension, more preferably more than 1.1 times, more preferably more than 1.2 times, and more preferably more than 1.5 times. In addition, with respect to the viewpoint of ensuring the minimum surface peeling force, the pitch P after extension is preferably less than 3 times relative to the value before extension, more preferably less than 2.8 times, more preferably less than 2.5 times, and more preferably less than 2.0 times.

[0073] As described above, the extension process is performed by pulling the inner side of the peripheral portion toward the base 310 while fixing the peripheral portion of the adhesive sheet. The displacement of the thickness direction of the adhesive sheet produced by the extension can be set to any amount that can expand the pitch P to the desired degree, for example, preferably 5mm, more preferably 10mm, more preferably 15mm, more preferably 20mm, more preferably 50mm, and more preferably 80mm. In addition, in order to fix the peripheral portion of the adhesive sheet, a fixed portion of a perfect circle is used here, and the surface of the base 310 pressed by the adhesive sheet is also a perfect circle, but this is an example, and these shapes are not particularly limited, and any one or both of these shapes can also be a square, etc. For example, a circular frame is used as a fixed portion, and the frame is pressed down while the adhesive sheet fixed to the frame is placed on the base 310, so that the adhesive sheet can be extended in the entire direction.

[0074] From the viewpoint of adjusting the surface peeling force, the pitch P of the protrusions 111 before extension is preferably greater than 1µm, more preferably greater than 5µm, further preferably greater than 10µm, further preferably greater than 15µm. On the other hand, from the viewpoint of increasing the contact area between the adhesive layer 110 and the element to improve the surface peeling force, the pitch P is preferably less than 100µm, more preferably less than 75µm, further preferably less than 50µm, further preferably less than 35µm, further preferably less than 25µm. Here, the pitch P of the protrusions 111 refers to the distance between the center point of an arbitrarily selected protrusion 111 and the center point of another protrusion 111 closest to the protrusion 111. For example, in Figure 2AIn the case of , the pitch P of the convex portion 111 represents the distance between the center point of the convex portion 111 on the straight line where the convex portions 111 are arranged at a fixed interval and the center point of another convex portion 111' closest to the convex portion 111. When the convex portions 111 are arranged on a plurality of straight lines, the pitch P represents the distance between the center points of the convex portions on the straight line where the convex portions 111 are arranged at the shortest pitch. In this specification, the interval between the convex portions 111 represents the interval between the centers of the convex portions.

[0075] The specific shape of the convex portion 111 is not particularly limited. For example, the convex portion 111 may have a pillar shape. As a specific example, the convex portion 111 may have a cylindrical shape or a prism shape. In addition, as described above, the convex portion 111 may extend in a linear shape or in a curved shape such as a wave shape. In addition, these convex portions 111 may be provided with a taper.

[0076] Figure 4A FIG. 1 is a cross-sectional view of the adhesive layer 110 according to one embodiment, which passes through the convex portion 111 and is perpendicular to the surface of the adhesive layer 110 . Figure 4A The convex portion 111 shown in FIG. 1 is provided with a taper, that is, the front end of the convex portion 111 becomes thinner. Figure 4B As shown, the front end of the protrusion 111 may be a curved surface. According to this configuration, the impact when the element separated from the holding substrate contacts the adhesive layer 110 is further mitigated, so that the adhesive layer 110 can easily capture the element without displacement. On the other hand, the front end of the protrusion may also be a flat surface.

[0077] like Figure 4A As shown, the surface of the adhesive layer 110 may have a flat concave portion and a convex portion 111 protruding from the concave portion. As described above, the adhesive layer 110 may have a plurality of convex portions 111 spaced apart from each other and defined by the concave portion.

[0078] As another example, the protrusion may be Figure 4B The convex portion 111 may also be as shown in FIG. Figure 4C As shown, it is in a T-shape. As another example, the convex portion 111 can be in the shape of a plurality of particle collections, mushroom-shaped, lotus leaf-shaped, or needle-shaped. As another example, the surface of the adhesive layer 110 can be rough or fibrous, and such a surface can also be said to have concave-convex.

[0079] The width or diameter of each convex portion 111 is preferably 1µm or more, more preferably 2µm or more, further preferably 5µm or more, further preferably 10µm or more. On the other hand, it is preferably 100µm or less, more preferably 50µm or less, further preferably 30µm or less, further preferably 20µm or less. Thus, the holding property of the element can be changed. Here, the width and diameter of the convex portion 111 respectively represent the minimum distance and maximum distance between two parallel lines contacting from both sides of the convex portion 111 in the surface of the concave portion ( Figure 4A Indicated by D in the figure).

[0080] In addition, the area of ​​each convex portion 111 is preferably 10 μm 2 More than 20µm is more preferred 2 More preferably, 30 μm 2 On the other hand, it is preferably 2000 μm 2 Below, more preferably 1000µm 2 Below, more preferably 500µm 2 Here, the area of ​​the convex portion 111 refers to the area of ​​the portion protruding from the surface of the concave portion ( Figure 4A In this case, it is the area of ​​a circle with diameter D).

[0081] In addition, the height of each convex portion 111 is preferably 1 µm or more, more preferably 3 µm or more, and further preferably 5 µm or more. On the other hand, the height of each convex portion 111 is preferably 20 µm or less, more preferably 15 µm or less, and further preferably 10 µm or less. Thus, the holding property of the element can be changed. Here, the height of the convex portion 111 is Figure 4A It is represented by H.

[0082] In addition, the total area of ​​the convex portion 111 relative to the area of ​​the adhesive layer 110 is preferably 1% or more, more preferably 5% or more, further preferably 10% or more, further preferably 18% or more, further preferably 40% or more. On the other hand, the total area of ​​the convex portion relative to the area of ​​the adhesive layer 110 is preferably 95% or less, more preferably 75% or less, further preferably 60% or less. Thus, the retention of the element can be changed.

[0083] The projections and depressions of the adhesive layer 110 can also be designed according to the shape of the element held by the adhesive sheet. For example, the ratio of the bonding area of ​​the adhesive layer 110 to an element to the area of ​​the element is preferably 1% or more, more preferably 2% or more, further preferably 3% or more, further preferably 4% or more, further preferably 5% or more, further preferably 7% or more, further preferably 10% or more, relative to 100% of the area of ​​the element. On the other hand, the ratio of the bonding area of ​​the adhesive layer 110 to an element to the area of ​​the element is preferably 95% or less, more preferably 70% or less, further preferably 50% or less, further preferably 30% or less. Figure 4A In the case of , the bonding area is equivalent to the area of ​​a circle with a diameter of T. It should be noted that the bonding area may change when the capture position of the element on the adhesive sheet is offset. In this case, regardless of the capture position of the element, the ratio of the bonding area can be within the above range.

[0084] In the present embodiment, the element 140 is peeled off from the adhesive layer 120 after it has been expanded in the surface direction. Here, for example, by bringing the element 140 held by the adhesive sheet after it has been expanded in the surface direction into contact with a transfer destination different from the adhesive sheet, and then pulling the transfer destination away, the element 140 can be peeled off to the transfer destination. As described above, the surface of the adhesive layer 120 has projections and depressions, and the surface peeling force is reduced by stretching. Therefore, in the peeling step of the element 140 of the present embodiment, the element 140 is peeled off by pulling the transfer destination away from the adhesive sheet without applying an external stimulus to the adhesive sheet, for example, by bringing the element 140 into contact with the transfer destination. Here, the external stimulus is described later. Figure 6 Energy is imparted or external stimulation such as pushing by a needle is used to reduce the adhesion between the substrate and the element. As described above, by picking up the object without external stimulation (or reducing external stimulation), the object can be peeled off while reducing damage to each component.

[0085] (Composition of Adhesive Layer (Adhesive Composition))

[0086] The adhesive composition forming the adhesive layer 110 includes resin. As examples of the resin contained in the adhesive composition, rubber resins such as polyisobutylene resins, polybutadiene resins, and styrene-butadiene resins, acrylic resins, urethane resins, polyester resins, olefin resins, silicone resins, and polyvinyl ether resins can be cited. In addition, the adhesive layer can have heat resistance, and as the material of this heat-resistant adhesive layer, polyimide resins and silicone resins can be cited. The adhesive composition forming the adhesive layer 110 can contain a copolymer having two or more structural units. The form of this copolymer is not particularly limited, and it can be any one of a block copolymer, a random copolymer, an alternating copolymer, and a graft copolymer. In addition, the resin contained in the adhesive composition forming the adhesive layer 110 can be composed of one resin or two or more resins.

[0087] The resin contained in the adhesive composition forming the adhesive layer 110 can be set as an adhesive resin having adhesiveness alone. In addition, the resin can be set as a polymer having a mass average molecular weight (Mw) of 10,000 or more. From the viewpoint of improving the adhesive force, the mass average molecular weight (Mw) of the resin is preferably 10,000 or more, more preferably 70,000 or more, and further preferably 140,000 or more. In addition, from the viewpoint of suppressing the shear storage modulus to below the specified value, the Mw is preferably 2 million or less, more preferably 1.2 million or less, and further preferably 900,000 or less. In addition, from the viewpoint of improving the adhesive force, the number average molecular weight (Mn) of the resin is preferably 10,000 or more, more preferably 50,000 or more, and further preferably 100,000 or more. In addition, from the viewpoint of suppressing the shear storage modulus to below the specified value, the Mn is preferably 2 million or less, more preferably 1 million or less, and further preferably 700,000 or less. As described later, when the adhesive layer 110 includes a resin derived from an energy-ray curable resin, its mass average molecular weight (Mw) and number average molecular weight (Mn) refer to the mass average molecular weight (Mw) and number average molecular weight (Mn) before the crosslinking reaction by energy application.

[0088] The glass transition temperature (Tg) of the resin is preferably -75°C or higher, more preferably -70°C or higher, and preferably -10°C or lower, more preferably -20°C or lower. By setting Tg within this range, the shear storage modulus of the obtained adhesive layer can be easily set within the range described below.

[0089] The amount of resin relative to the total amount of components constituting the adhesive composition forming the adhesive layer 110 can be appropriately set according to the required adhesion force and shear storage modulus of the adhesive layer 110, and is preferably 30 mass % or more, more preferably 40 mass % or more, further preferably 50 mass % or more, further preferably 55 mass % or more, further preferably 60 mass % or more, and preferably 99.99 mass % or less, more preferably 99.95 mass % or less, further preferably 99.90 mass % or less, further preferably 99.80 mass % or less, further preferably 99.50 mass % or less.

[0090] Thermoplastic resin

[0091] In one embodiment, the resin contained in the adhesive composition forming the adhesive layer 110 may contain a thermoplastic resin. That is, the adhesive layer 110 may be formed of a thermoplastic resin. When a thermoplastic resin is used, the resin is softened by heating, and it is easy to form a concave-convex shape on the adhesive layer 110, and it is also easy to maintain the concave-convex shape formed by cooling the resin. Examples of thermoplastic resins include rubber resins, acrylic resins, urethane resins, and olefin resins. As an example, polybutadiene thermoplastic elastomers using butadiene as a monomer, styrene thermoplastic elastomers using styrene as a monomer, and acrylic thermoplastic elastomers using (meth)acrylate as a monomer can be listed.

[0092] Energy ray curing resin (A)

[0093] The resin contained in the adhesive composition forming the adhesive layer 110 of the present embodiment may contain an energy-ray-curable resin (A). "Energy-ray-curable" refers to the property of being cured by irradiating energy rays, and the energy-ray-curable resin (A) refers to a resin that is cured by irradiating energy rays. In addition, "energy rays" refers to electromagnetic waves or charged particle beams that have energy quanta in electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays, radiation, or electron beams. For example, ultraviolet rays can be irradiated by using an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, or a UV-LED (Ultraviolet Light Emitting Diode) as an ultraviolet light source. The electron beam can be irradiated with an electron beam generated by an electron beam accelerator or the like. In addition, "energy-ray polymerizability" refers to the property of being polymerized by irradiating energy rays.

[0094] When such an energy-beam-curable resin (A) is used, the formed concavo-convex shape can be easily maintained by applying energy to the resin (for example, irradiating it with energy beams) after the concavo-convex shape is formed on the resin.

[0095] From the viewpoint of improving adhesive strength, the mass average molecular weight (Mw) of the energy-beam curable resin (A) is preferably 10,000 or more, more preferably 50,000 or more, further preferably 100,000 or more, and further preferably 150,000 or more. Furthermore, from the viewpoint of suppressing the shear storage modulus to be below a predetermined value, it is preferably 2,000,000 or less, more preferably 1,000,000 or less, and further preferably 200,000 or less.

[0096] As the energy-ray curable resin (A), a polymer having a polymerizable functional group introduced therein can be used. The polymerizable functional group is a functional group that undergoes crosslinking by the application of energy (e.g., irradiation with energy rays). Examples of the polymerizable functional group include alkenyl groups such as vinyl and allyl, (meth)acryloyl, oxetanyl, and epoxy groups.

[0097] From the viewpoint of easily maintaining the concavo-convex shape of the adhesive layer, the average value of the number of polymerizable functional groups per molecule in the energy ray curable resin (A) is preferably 1.5 or more, more preferably 2 or more. On the other hand, from the viewpoint of improving the adhesiveness and flexibility of the adhesive layer, the average value is preferably 20 or less, more preferably 15 or less, and further preferably 10 or less.

[0098] In one embodiment, as the energy-ray-curable resin (A), a diene rubber composed of a polymer having a polymerizable functional group at the main chain end and / or side chain can be used. Diene rubber refers to a rubber-like polymer having a double bond in the polymer main chain. As a specific example of diene rubber, a polymer using butadiene or isoprene as a monomer (i.e., having a butene-diyl group or a pentene-diyl group as a structural unit) can be listed. In one embodiment, as the energy-ray-curable resin (A), a polybutadiene resin (PB resin), a styrene-butadiene-styrene block copolymer (SBS resin), and a styrene-isoprene-styrene block copolymer can be listed.

[0099] The amount of the energy-ray-curable resin (A) in the total amount of resins in the adhesive composition can be appropriately set according to the required adhesive force and shear storage modulus of the adhesive layer 110, and is preferably 0% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, further preferably 50% by mass or more, and is preferably 100% by mass or less, and more preferably 97% by mass or less.

[0100] Acrylic resin (B)

[0101] In one embodiment, the thermoplastic resin may be an acrylic resin (B). From the viewpoint of improving adhesive strength, the mass average molecular weight (Mw) of the acrylic resin (B) is preferably 10,000 or more, more preferably 100,000 or more, and further preferably 500,000 or more. Furthermore, from the viewpoint of suppressing the shear storage modulus to be below a predetermined value, it is preferably 2,000,000 or less, more preferably 1,500,000 or less, and further preferably 1,000,000 or less.

[0102] The glass transition temperature (Tg) of the acrylic resin (B) is preferably -75°C or higher, more preferably -70°C or higher, and preferably 5°C or lower, more preferably -20°C or lower. When Tg is within this range, the shear storage modulus of the resulting adhesive can be easily within a range.

[0103] When the acrylic resin (B) has two or more structural units, the glass transition temperature (Tg) of the acrylic resin (B) can be calculated using the Fox equation. As the Tg of the monomer from which the structural unit is derived, the value described in the Polymer Data Handbook or the Adhesion Handbook can be used.

[0104] Examples of the (meth)acrylic acid ester constituting the acrylic resin (B) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, myristyl (meth)acrylate, pentadecyl (meth)acrylate, palmityl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, and the like. The alkyl group of the ester is a chain-like (meth)acrylate having 1 to 18 carbon atoms; cycloalkyl (meth)acrylates such as isoborneol (meth)acrylate and dicyclopentanyl (meth)acrylate; aralkyl (meth)acrylates such as benzyl (meth)acrylate; cycloalkenyl (meth)acrylates such as dicyclopentenyl (meth)acrylate; cycloalkenyloxyalkyl (meth)acrylates such as dicyclopentenyloxyethyl (meth)acrylate; imide (meth)acrylate; glycidyl (meth)acrylate and other (meth)acrylate containing a glycidyl group; hydroxymethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate and other (meth)acrylate containing a hydroxyl group; N-methylaminoethyl (meth)acrylate and other (meth)acrylate containing a substituted amino group. Here, the "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

[0105] The acrylic resin (B) may be a resin obtained by copolymerizing one or more monomers selected from (meth)acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, and N-methylolacrylamide, in addition to (meth)acrylate.

[0106] The monomer constituting the acrylic resin (B) may be one kind or two or more kinds. When two or more kinds are used, the combination and ratio of the monomers may be arbitrarily selected.

[0107] The acrylic resin (B) may have a functional group capable of bonding to other compounds, such as a vinyl group, a (meth)acryloyl group, an amino group, a carboxyl group, an isocyanate group, etc., in addition to a hydroxyl group. These functional groups, including the hydroxyl group of the acrylic resin (B), may bond to other compounds via a crosslinking agent (C) described later, or may directly bond to other compounds without the crosslinking agent (C).

[0108] The amount of the acrylic resin (B) in the total amount of resins in the adhesive composition can be appropriately set according to the required adhesive force and shear storage modulus of the adhesive layer 110, and is preferably 0 mass % or more, more preferably 10 mass % or more, further preferably 20 mass % or more, further preferably 50 mass % or more, and is preferably 100 mass % or less, more preferably 95 mass % or less, further preferably 80 mass % or less, and further preferably 60 mass % or less.

[0109] In addition, in one embodiment, the adhesive composition may contain an energy-ray curable resin (A) and an acrylic resin (B). The relationship between the content of the energy-ray curable resin (A) and the acrylic resin (B) can be appropriately set according to the required adhesive force and shear storage modulus of the adhesive layer 110. In one embodiment, the content of the acrylic resin (B) in the total content of the energy-ray curable resin (A) and the acrylic resin (B) is preferably 0% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, further preferably 50% by mass or more, and preferably 100% by mass or less, more preferably 95% by mass or less, further preferably 80% by mass or less, and further preferably 60% by mass or less.

[0110] The adhesive composition forming the adhesive layer 110 may contain components other than the resin. For example, the adhesive composition may contain one or more of a crosslinking agent (C), a photopolymerization initiator (D), an antioxidant (E), and other additives.

[0111] Crosslinking agent (C)

[0112] The adhesive composition may also contain a crosslinking agent (C) for bonding the functional groups of the resin with other compounds to form crosslinks. Examples of the crosslinking agent (C) include isocyanate crosslinking agents (crosslinking agents having an isocyanate group) such as toluene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, and adducts of these diisocyanates, epoxy crosslinking agents (crosslinking agents having a glycidyl group) such as ethylene glycol glycidyl ether, aziridine crosslinking agents (crosslinking agents having an aziridine group) such as hexa[1-(2-methyl)-aziridinyl]triphosphine triazine, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelate, and isocyanurate crosslinking agents (crosslinking agents having an isocyanuric acid skeleton).

[0113] The adhesive composition may contain one crosslinking agent or two or more crosslinking agents. From the viewpoint of appropriately performing a crosslinking reaction, the content of the crosslinking agent (C) in the adhesive composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 1% by mass or more, and on the other hand, is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 2% by mass or less.

[0114] Photopolymerization initiator (D)

[0115] The adhesive composition may also contain a photopolymerization initiator (D) that starts a crosslinking reaction by applying energy (e.g., irradiation with energy rays). When the adhesive composition contains an energy-curable resin (A), the adhesive layer 110 further contains a photopolymerization initiator (D), thereby allowing the crosslinking reaction to proceed even when applying relatively low energy.

[0116] Examples of the photopolymerization initiator (D) include 1-hydroxycyclohexyl phenyl ketone, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzyl phenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, bibenzyl, biacetyl, 8-chloroanthraquinone, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0117] The adhesive composition may contain one polymerization initiator or two or more polymerization initiators. The content of the photopolymerization initiator (D) in the adhesive composition is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and further preferably 1% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass or less.

[0118] Antioxidant (E)

[0119] The adhesive composition may contain an antioxidant (E). For example, examples of the antioxidant (E) include phenolic antioxidants such as hindered phenolic compounds, aromatic amine antioxidants, and phosphorus antioxidants such as sulfur-based and phosphate-based compounds.

[0120] Furthermore, the adhesive composition forming the adhesive layer 110 may contain one or more of an ultraviolet absorber, a light stabilizer, a resin stabilizer, a filler, a pigment, an extender, a softener, and the like.

[0121] (Base material)

[0122] The substrate 120 provided in the adhesive sheet of the present embodiment functions as a support body for supporting the adhesive layer 110. The type of the substrate 120 is not particularly limited, and may be a hard substrate or a soft substrate. From the perspective of improving the cushioning property when capturing the element, facilitating installation on other components, improving the peeling property, facilitating lamination, or being able to adopt a roll form, the substrate 120 may be a soft substrate. As the substrate 120, for example, a resin film may be used.

[0123] The resin film is a film using a resin material as a main material, and may be formed of a resin material, or may contain additives other than the resin material. The resin film may also have laser transmittance.

[0124] As specific examples of resin films, there can be listed: polyethylene films such as low-density polyethylene films, linear low-density polyethylene films, and high-density polyethylene films, polypropylene films, polybutylene films, polybutadiene films, polymethylpentene films, ethylene-norbornene copolymer films, and norbornene resin films; ethylene-vinyl acetate copolymer films, ethylene-(methyl) acrylic acid copolymer films, and ethylene-(methyl) acrylic acid ester copolymer films; polyvinyl chloride films such as polyvinyl chloride films and vinyl chloride copolymer films; polyester films such as polyethylene terephthalate films and polybutylene terephthalate films; polyurethane films; polyimide films; polystyrene films; polycarbonate films; and fluororesin films. In addition, films containing a mixture of two or more materials, cross-linked films formed by cross-linking the resins forming these films, and modified films such as ionomer films can also be used. In addition, the substrate 120 can also be a laminated film formed by laminating two or more resin films.

[0125] From the perspective of versatility, high strength and easy prevention of warping, and heat resistance, the resin film can be a single-layer film selected from the group consisting of polyethylene film, polyester film, and polypropylene film, or a laminated film formed by laminating two or more films selected from the group. In this embodiment, in order to easily expand the adhesive sheet, as the substrate 120, i.e., the resin film, a polyolefin film or a vinyl chloride copolymer film of the adhesive sheet can also be used. Here, the polyolefin film of this embodiment includes various polyethylene films, various polypropylene films, and ethylene copolymers including EMAA (ethylene-methacrylic acid copolymer). In addition, as a vinyl chloride copolymer film, for example, a vinyl chloride-vinylidene chloride copolymer film, a vinyl chloride-vinyl acetate copolymer film, and a vinyl chloride-ethylene copolymer film can be used.

[0126] The thickness of the substrate 120 is not particularly limited. From the perspective of achieving both support and rollability, it can be preferably set to 10 µm or more, more preferably 25 µm or more, and further preferably 40 µm or more, and preferably 500 µm or less, more preferably 200 µm or less, and further preferably 90 µm or less. The thickness of the substrate 120 can preferably range from 10 µm to 500 µm, more preferably from 25 µm to 200 µm, and further preferably from 40 µm to 90 µm.

[0127] The substrate 120 of the present embodiment extends in the surface direction simultaneously with the adhesive layer 110 when the adhesive sheet is extended. The substrate 120 can be extended to more than 2% in the surface direction by the extension of the adhesive sheet, for example. The extension of the substrate 120 is carried out by the extension of the adhesive sheet, so it can be carried out in the entire direction as described above, or in one direction, or in two directions, or in multiple directions. From the perspective of making it easier to extend the adhesive sheet, the substrate 120 can extend more than 2% in the surface direction, or more than 8%, or more than 15%, or more than 30%, or more than 50%, or more than 80%, or more than 85%. In addition, from the perspective of ensuring the minimum hardness during extension, the substrate 120 can extend up to 300%, or up to 250%, or up to 200%, or up to 150%, or up to 120%. The expansion rate of the substrate of the present embodiment is represented by the area increase rate of the substrate surface during extension.

[0128] From the viewpoint of the ease of elongation during extension, the tensile modulus of the substrate 120 can be preferably set to 2500MPa or less, more preferably set to 2000MPa or less, further preferably set to 1500MPa or less, and further preferably set to 1000MPa or less. In addition, from the viewpoint of controlling the ease of elongation during extension, the tensile modulus of the substrate 120 can be preferably set to 50MPa or more, more preferably set to 100MPa or more, further preferably set to 150MPa or more, further preferably set to 300MPa or more, further preferably set to 350MPa or more, further preferably set to 500MPa or more, and further preferably set to 700MPa or more.

[0129] In addition, the elongation of the substrate 120 during extension can also be evaluated by, for example, the elongation at break. From the perspective of ease of elongation during extension, the elongation at break of the substrate 120 can be preferably set to 105% or more, more preferably 200% or more, further preferably 400% or more, and further preferably 600% or more. In addition, from the perspective of controlling the ease of elongation during extension, the elongation at break of the substrate 120 can be preferably set to 1500% or less, more preferably 1200% or less, further preferably 1000% or less, and further preferably 800% or less.

[0130] (Peel-off sheet)

[0131] Furthermore, the pressure-sensitive adhesive sheet of the present embodiment may include a release sheet that contacts the pressure-sensitive adhesive layer 110 and has a concavoconvex surface complementary to the concavoconvex surface of the pressure-sensitive adhesive layer 110. The release sheet includes a release layer 510. Figure 5 It is a side view showing the shape of the release layer 510 with respect to the adhesive layer 110 of this embodiment.

[0132] As described above, the release layer 510 has a concavoconvex surface complementary to the concavoconvex surface of the adhesive layer 110. That is, the pitch P and height of the convex portions 511 in the release layer 510 are the same as the pitch P and height of the convex portions 111. Here, the convex portions 511 may have the same shape as the concave portions of the adhesive layer 110, and the width and diameter may be different from those of the concave portions of the adhesive layer 110. In the present embodiment, the convex portions 111 are arranged in a lattice shape, and the convex portions 511 are arranged in a lattice shape in such a manner that the center of the convex portions 511 is located at the center of the lattice formed by the convex portions 111.

[0133] The release sheet may also include a substrate 520 on the surface not in contact with the adhesive layer 110. The substrate 520 may be designed in the same manner as described for the substrate 120 of the adhesive sheet, but does not need to be the same composition and structure as the substrate 120. For example, the substrate 120 of the adhesive sheet may be EMAA, and the substrate 520 of the release sheet may be a polyethylene terephthalate film or the like. In addition, the release sheet may also include a primer layer (not shown) between the release layer 510 and the substrate 520.

[0134] (Other layers)

[0135] The adhesive sheet may also have a layer other than the substrate 120 and the adhesive layer 110. For example, an additional adhesive layer may be provided on the surface of the substrate 120 opposite to the adhesive layer 110. The adhesive sheet can be attached to other substrates such as quartz glass via such an adhesive layer. The type of the additional adhesive layer is not particularly limited, and for example, a common adhesive may be used to form the additional adhesive layer.

[0136] (Method for producing adhesive sheet)

[0137] The manufacturing method of the adhesive sheet is not particularly limited. For example, an adhesive sheet having an adhesive layer 110 on a substrate 120 can be made in the following manner. First, an organic solvent is added to the adhesive composition forming the adhesive layer 110 to prepare a solution of the adhesive composition. Next, the solution is applied to the substrate to form a coating film and then dried, thereby providing an adhesive layer on the substrate 120. Furthermore, by performing a process of providing a concavo-convex surface on the adhesive layer, an adhesive layer 110 having a concavo-convex surface can be formed.

[0138] Examples of organic solvents for preparing the solution of the adhesive composition include toluene, ethyl acetate, and methyl ethyl ketone. Examples of the method for applying the solution include spin coating, spray coating, rod coating, knife coating, roll coating, roll knife coating, blade coating, die coating, gravure coating, and printing methods (such as screen printing and inkjet).

[0139] There is no particular restriction on the treatment of setting concavoconvex on the surface of the adhesive layer. For example, concavoconvex can be set on the surface of the adhesive layer using an embossing method. In the embossing method, a mold having a shape complementary to the concavoconvex to be set can be used. Specifically, the adhesive layer provided on the substrate is heated while the mold is pressed, so that the concavoconvex can be set on the surface of the adhesive layer. As a more specific method, the adhesive layer can be pressed by a mold, the adhesive layer is heated and maintained for a specified time, and then the adhesive layer is cooled and the mold is removed. When heating the adhesive layer, for example, the adhesive layer can be heated to a temperature higher than the softening point of the adhesive layer. In addition, the time for maintaining the adhesive layer in a heated state is also not particularly limited, for example, it can be maintained for more than 10 seconds, or it can be maintained for less than 10 minutes. As a specific method for heating the adhesive layer while pressing the adhesive layer using a mold, a method for vacuum laminating the adhesive layer provided on the substrate and the mold can be cited. It should be noted that, it is also possible to replace the steps of forming the adhesive layer and forming the concavoconvex in these two stages, and to form the adhesive layer 110 with concavoconvex on the surface on the substrate by a step of one stage.

[0140] As another method, a solution of an adhesive composition can be sprayed to provide an adhesive layer 110 having a concavo-convex shape. In addition, a filler can be added to a solution of an adhesive composition, and the solution can be applied to provide an adhesive layer 110 having a rough surface or a fibrous surface. As another method, a printing method such as an inkjet method can be used to apply a solution of an adhesive composition in a desired pattern to directly provide an adhesive layer having a concavo-convex shape on a substrate.

[0141] In addition, the adhesive sheet without substrate 120 can be made by forming the adhesive composition into a sheet. In addition, the adhesive layer can also be formed by applying the liquid adhesive comprising the adhesive composition to any object. In these cases, the surface of the adhesive layer can be provided with a concavo-convex process after forming the adhesive layer, and the adhesive layer can also be formed by forming a concavo-convex method on the surface.

[0142] (Method for Manufacturing Electronic Components or Semiconductor Devices Using Adhesive Sheet of the Present Embodiment)

[0143] The adhesive sheet of the present embodiment as described above can be used to hold an element away from a holding substrate. For example, the adhesive sheet can be used as a grain capture sheet for capturing grains such as semiconductor grains. The element is used to manufacture electronic parts or semiconductor devices. That is, the adhesive sheet can be used in the manufacture of electronic parts or semiconductor devices.

[0144] The manufacturing method of the electronic component or semiconductor device of the present embodiment includes the following steps: separating the element from the holding substrate; deforming the convex portion of the adhesive layer to hold the element on the adhesive sheet; and restoring the convex portion to a convex shape to promote the separation of the element from the adhesive sheet. In addition, the electronic component or semiconductor device can also be manufactured by further processing the element held on the adhesive sheet. Figure 6 Flowchart of Fig. 7A as well as Figure 7B A schematic diagram illustrating the separation and capture of components, Fig. 8A as well as Figure 8B The expansion (extension) of the pressure-sensitive adhesive sheet will be described in detail with reference to a schematic diagram of the pressure-sensitive adhesive sheet.

[0145] (S10: Preparation of holding substrate)

[0146] exist Figure 6 In the step S10 shown, a holding substrate with components attached thereto is prepared. The type of components is not particularly limited. The components may be, for example, semiconductor chips such as LED chips, semiconductor chips with protective films, semiconductor chips with die-attaching films (DAF), etc. In addition, the components may be micro-LEDs, mini-LEDs, power devices, MEMS (MicroElectro Mechanical Systems) or control chips, or components thereof. In addition, the components may be monolithic objects such as wafers, panels or substrates. For example, the components may also have a circuit surface on which an integrated circuit having circuit components such as transistors, resistors and capacitors is formed. In addition, the components are not necessarily limited to monolithic objects, but may also be various wafers or various substrates that are not monolithic.

[0147] The size of the element is not particularly limited. For example, the size of the element can be preferably 100 μm.2 More than 500µm 2 More preferably, 1000 μm 2 On the other hand, the size of the element may preferably be 100 mm 2 Below, more preferably 25mm 2 Below, more preferably 1mm 2 When using small-sized components, the laser lift-off method described later is suitable for separating the components because it is easy to selectively separate the small components.

[0148] As wafers, for example, semiconductor wafers such as silicon wafers, silicon carbide (SiC) wafers, compound semiconductor wafers (such as gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, indium phosphide (InP) wafers, and gallium nitride (GaN) wafers) can be listed. The size of the wafer is not particularly limited, but is preferably 6 inches (about 150 mm in diameter) or larger, and more preferably 12 inches (about 300 mm in diameter) or larger. It should be noted that the shape of the wafer is not limited to a circle, and can be, for example, a square or a rectangle.

[0149] As the panel, a fan-out semiconductor package (such as FOWLP or FOPLP) can be cited. That is, the processed object can be a semiconductor package before or after singulation in the fan-out semiconductor package manufacturing technology. The size of the panel is not particularly limited, for example, it can be a square substrate of about 300 to 700 mm.

[0150] Examples of the substrate include a glass substrate, a sapphire substrate, and a compound semiconductor substrate.

[0151] The type of the holding substrate is also not particularly limited. For example, the holding substrate may be an adhesive sheet or a tray. The adhesive sheet may have an adhesive layer, and the adhesive layer may be provided on the substrate. In this case, the holding substrate may hold the element on the adhesive layer. The substrate may be a resin film or a hard substrate.

[0152] The method for preparing the holding substrate for holding the element is not particularly limited. For example, a semiconductor wafer may be attached to the holding substrate, and then the semiconductor wafer may be cut. By cutting the semiconductor wafer, the element may be obtained, and thus the holding substrate with the element attached thereto may be obtained.

[0153] As another method, the element obtained by cutting the semiconductor wafer can be transferred to the holding substrate, thereby obtaining the holding substrate with the element attached. For example, after cutting the semiconductor wafer held on the wafer substrate, the obtained element can be brought into close contact with the adhesive layer of the holding substrate. Then, by applying an external stimulus such as a laser, the adhesion between the wafer substrate and the element can be reduced. Through this step, the element can be transferred from the wafer substrate to the holding substrate.

[0154] In addition, as described later, in one embodiment, the element is separated from the holding substrate by irradiation with laser (laser lift-off method). When this method is used, the adhesive layer of the holding substrate may contain a laser absorbent. As the laser absorbent, for example, one or more selected from pigments and dyes can be cited.

[0155] (S20: Separation of components)

[0156] exist Figure 6 In step S20 shown, the element attached to the holding substrate is separated from the holding substrate by external stimulation. Specifically, the element is relatively separated relative to the holding substrate. Moreover, the element is relatively close to the adhesive sheet. Then, the element is separated from the holding substrate and captured on the adhesive sheet by contacting the adhesive layer of the adhesive sheet. The type of external stimulation is not particularly limited, and examples thereof include energy imparting, cooling, extension of the holding substrate, and physical stimulation (for example, pushing the back side of the holding substrate using a pin, etc.). By using one or more of these external stimuli, the bonding force between the holding substrate and the element can be reduced, and the element can be separated from the holding substrate.

[0157] In this embodiment, the component capture in step S30 can be performed in a manner that the relative arrangement of the plurality of components on the holding substrate is different from the relative arrangement of the plurality of components on the adhesive sheet. Therefore, in step S20, an external stimulus can be selectively applied to a portion of the plurality of components attached to the holding substrate or to the attachment portion of the component in the holding substrate.

[0158] As a method of imparting energy, local heating, light irradiation or heat ray irradiation can be listed. In addition, as a method of light irradiation, infrared irradiation, visible light irradiation and laser irradiation can be listed. Preferably, laser irradiation is performed as an external stimulus, that is, the element is separated from the holding substrate by laser stripping. In this case, the laser is irradiated toward the pasting part of the specific element in the holding substrate. For example, such laser irradiation can be performed from the surface of the holding substrate that is opposite to the element. Then, gas is generated at the contact part between the specific element and the holding substrate. For example, when the laser is absorbed by the adhesive layer, at least a part of the adhesive layer sublimates, thereby generating gas. As described above, at least a part of the adhesive layer sublimates, thereby reducing the bonding area between the specific element and the adhesive layer, so the bonding force between the specific element and the holding substrate decreases. In addition, the pressure of the generated gas will also reduce the bonding force between the specific element and the holding substrate. As a result, the specific element is separated from the holding substrate.

[0159] The irradiation conditions of the laser are not particularly limited. From the perspective of selectively separating a portion of the elements efficiently, the frequency of the laser is preferably 10,000 Hz or more and 100,000 Hz or less. In addition, the beam diameter of the laser is preferably 10 μm or more, more preferably 20 μm or more, on the other hand, preferably 100 μm or less, more preferably 40 μm or less. The output of the laser is preferably 0.1 W or more and 10 W or less. The scanning speed of the laser is preferably 50 mm / sec or more and 2000 mm / sec or less.

[0160] (S30: Component Capture)

[0161] In step S30, the element separated from the holding substrate is captured on the adhesive sheet. Specifically, the element is relatively far away from the holding substrate. Moreover, the element is relatively close to the adhesive sheet. Then, the element is captured on the adhesive sheet by contacting the adhesive layer of the adhesive sheet.

[0162] like Fig. 7A As shown in FIG. 1 , the separated element 140a is captured at the position (P1) on the adhesive sheet 150 by positioning the position (P1) on the adhesive sheet 150 so as to face the element 140a attached to the holding substrate 130. Figure 7B As shown, the separated component 140b is captured at the position (P2) on the adhesive sheet 150 by positioning the position (P2) on the adhesive sheet 150 in a manner opposite to the component 140b adhered to the holding substrate 130. As described above, the components can be separated and captured while changing the relative position of the holding substrate and the adhesive sheet in the surface direction. As described above, the components can be positioned in a manner that the relative configuration of the plurality of components on the holding substrate is different from the relative configuration of the plurality of components on the adhesive sheet. Of course, as already described, in the case of using an adhesive sheet having a flat surface, due to the pressure generated between the component and the adhesive sheet, Fig. 7A In the example of , the component 140a may be captured at a position offset from the position (P1). However, since the surface of the adhesive layer has irregularities, the pressure generated between the component and the adhesive layer is relieved, making it easier to capture the component at a desired position of the adhesive sheet.

[0163] In one embodiment, the substrate and the adhesive sheet are kept stationary, and the element separated from the substrate is moved toward the adhesive sheet. For example, in the case of using a laser stripping method, the element can move toward the adhesive sheet by the pressure of the gas generated by the irradiation of the laser. On the other hand, the element does not have to move. For example, the substrate can be moved away from the element. In addition, the adhesive sheet can also be moved in a manner close to the element.

[0164] (S40: Component Processing)

[0165] exist Figure 6 In the step S40 shown, a process for manufacturing electronic parts or semiconductor devices is performed using the elements retained on the adhesive sheet. The process for manufacturing electronic parts or semiconductor devices is not particularly limited, and for example, the transfer of the elements retained on the adhesive sheet to the wiring substrate can be cited. Wiring connected to the elements can also be provided on the wiring substrate. In this case, the positions of the elements on the wiring substrate are predetermined. Therefore, in step S20, the adhesive sheet can be used to capture multiple elements in a configuration consistent with the relative configuration between multiple elements on the wiring substrate. Next, the wiring substrate is joined to the surface of the multiple elements on the opposite side of the adhesive sheet. Then, in the next step S50, the separation of the elements is promoted so that the elements are separated from the adhesive sheet.

[0166] (S50: Separation of components)

[0167] exist Figure 6 In step S50 shown in FIG. 1 , the components held by the adhesive sheet are separated. In this embodiment, the surface peeling force when the components are separated can be reduced by stretching the adhesive sheet. Fig. 8A As shown, the components 140a to 140d are held on the adhesive sheet 150. In addition, Figure 8B It means from Fig. 8A Here, for example, the portion opposite to the portion of the adhesive layer holding the element is placed on the base 310, and the peripheral portion 320 (annular frame) of the adhesive sheet is pressed down as indicated by the arrow (P3) at a temperature of not less than -20°C and not more than 80°C, thereby allowing the adhesive sheet 150 to be extended.

[0168] Next, the plurality of components 140a to 140d are separated from the adhesive sheet 150. By extending, the pitch P of the convex portion 111 of the capturing component is enlarged, and the surface peeling force of the adhesive layer 110 on the component is reduced, so that it becomes easier to pick up these components from the adhesive sheet. Therefore, in the extended state, by making the component contact the transfer destination, the transfer destination is pulled away from the adhesive sheet without applying other external stimulation, and the component can be separated from the adhesive sheet 150. Through this sequence, an electronic component or a semiconductor device having a component (such as a semiconductor component) can be manufactured.

[0169] It should be noted that, although the separation of the components is described in S50 without applying an external stimulus other than the extension of the adhesive sheet 150, other external stimuli may be applied for the separation of the components. The external stimulus may be any external stimulus that can be applied to the holding substrate in S20, such as applying energy to the adhesive sheet 150.

[0170] Example

[0171] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples. Parts and % in each example are based on mass unless otherwise specified.

[0172] The following compounds were used in Examples and Comparative Examples.

[0173] <(A) ingredient>

[0174] · Energy-beam curable resin (A1): SBS having a vinyl group in the side chain (styrene-butadiene-styrene block copolymer (SBS) having a 1,2-vinyl group in the side chain [having a branched structure and a radial structure with the branch point as the central core, number average molecular weight (Mn) of 160,000, mass average molecular weight (Mw) of 180,000, styrene block content of 20% by mass, butadiene block content of 80% by mass, and the content of structural units having a 1,2-vinyl group in the side chain of all structural units constituting the butadiene block of 42 mol%, and a melt flow rate of 5 g / 10 min measured under the conditions of a temperature of 200° C. and a load of 5 kg])

[0175] · Energy-beam curable resin (A2): PB having a vinyl group on the side chain (polybutadiene copolymer having a 1,2-vinyl group on the side chain [mass average molecular weight (Mw) of 5,500, glass transition temperature of -49°C, liquid at room temperature])

[0176] <Ingredient (C)>

[0177] Photopolymerization initiator (C1): Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0178] <(E) Antioxidant>

[0179] · Antioxidant (E1): a mixture of a hindered phenol antioxidant and a phosphorus antioxidant in a mass ratio of 1:1

[0180] (Example 1)

[0181] An adhesive composition was prepared by dissolving 100 parts by mass of an energy-ray curing resin (A1), 50 parts by mass of an energy-ray curing resin (A2), 3 parts by mass of a photopolymerization initiator (C1), and 3 parts by mass of an antioxidant (E1) in toluene. The adhesive composition was applied to the release-treated surface of a release sheet (manufactured by Lintec Co., Ltd., trade name: SP-PET381130, obtained by laminating a silicone release agent on a polyethylene terephthalate film, thickness 38µm), and the resulting coating was dried at 100°C for 2 minutes to form an adhesive layer with a thickness of 25µm. The non-embossed surface of an EMAA substrate (ethylene-methacrylic acid copolymer film, acid content 9% by mass, manufactured by Riken Technos Co., Ltd., one side surface embossed to become concave-convex, thickness: 80µm, elongation at break 490%) was bonded to the adhesive layer to produce an adhesive sheet.

[0182] After the release sheet was peeled off, the adhesive layer of the adhesive sheet was attached to a stamp mold with a concave shape formed in advance, and vacuum laminated at 60°C for 300 seconds. Next, an ultraviolet irradiator (manufactured by Heraeus) was used at an illumination of 200 mW / cm 2 、Light intensity 800mJ / cm 2 By irradiating with ultraviolet rays, a pressure-sensitive adhesive sheet having a concavo-convex shape on the surface is produced.

[0183] The concavo-convex shape of the adhesive layer of the adhesive sheet Figure 2A The columns are arranged in a grid shape. The pitch P between the columns in the adhesive sheet is 20 μm. Figure 4A The height (H) of each column shown is 8µm, the diameter (T) of the front end is 8µm, and the diameter (D) of the base is 16µm. In addition, the ratio of the area of ​​the bonding portion of the adhesive layer and the element to be captured (i.e., the area of ​​the front end surface of the convex portion) to the area of ​​the adhesive sheet is about 12.6%. It should be noted that the above-mentioned stamp mold uses a stamp mold having a surface shape complementary to this concave and convex shape.

[0184] (Tensile modulus of substrate)

[0185] In addition, in this embodiment, the substrate used in the embodiment is a substrate cut into 150 mm in the MD direction and 15 mm in the TD direction as a test sample. For this test sample, the tensile modulus in an environment of 23°C and 50% RH (relative humidity) is measured in accordance with JIS K 7161-1: 2014 and JIS K 7127: 1999. Specifically, for the above test sample, a tensile tester (manufactured by Shimadzu Corporation, product name "Autograph (registered trademark) AG-IS 500N") is used. After setting the chuck spacing to 100 mm, a tensile test is performed at a speed of 200 mm / min to measure the tensile modulus (MPa) in the MD direction of the support. In this embodiment, the tensile modulus of the substrate measured is 165 MPa.

[0186] In addition, MD in MD direction is an abbreviation of Machine Direction, for example, the MD direction of a substrate indicates the length direction when the substrate is manufactured. In addition, TD in TD direction is an abbreviation of Transverse Direction, for example, the TD direction of a substrate indicates the width direction when the substrate is manufactured.

[0187] (Example 2)

[0188] A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 1 except that the amount of the energy-beam curable resin (A2) was changed to 75 parts by mass.

[0189] (Comparative Examples 1 and 2)

[0190] PSA sheets were prepared in the same manner as in Examples 1 and 2 except that the stamp mold and the PSA layer were not attached and vacuum lamination was not performed, and these were respectively referred to as Comparative Examples 1 and 2. In these Comparative Examples, no irregularities were formed on the surface of the PSA layer.

[0191] (Determination of shear storage modulus)

[0192] The adhesive layers were formed from the adhesive compositions obtained in the examples and comparative examples, and an ultraviolet irradiator (manufactured by Heraeus) was used to irradiate the adhesive layers at an illumination of 200 mW / cm 2 、Light intensity 800mJ / cm 2 The adhesive layer with a thickness of 1 mm was prepared by irradiating with ultraviolet rays. The obtained adhesive layer was punched into a cylindrical shape with a diameter of 8 mm, and the shear storage modulus of the adhesive layer at 23°C was measured by a torsional shear method using a viscoelasticity measuring device (manufactured by Anton Paar, product name "MCR302") under the conditions of a test start temperature of -60°C, a test end temperature of 150°C, a heating rate of 3.5°C / min, and a frequency of 1 Hz.

[0193] (Preparation of samples for surface peeling force measurement)

[0194] The adhesive layer of the adhesive sheet obtained in Example was attached to a ring frame (made of stainless steel), and the adhesive sheet was cut so as to be aligned with the outer diameter of the ring frame.

[0195] The wafer substrate (mirror-finished silicone wafer, 6 inches, 150µm thick) was fixed to a separately prepared dicing tape and cut into 10mm×10mm squares to make a plurality of components (silicon chips, the dimensions of the components were 10mm×10mm×150µm). The plurality of components obtained were pasted to the central part of the inner side of the annular frame of the adhesive layer of the adhesive sheet, and the components were transferred from the dicing tape to the adhesive sheet by peeling off the dicing tape. At this time, the surface was adjusted in such a way that the mirror surface of the silicon chip was pasted to the adhesive layer of the adhesive sheet, and the pasting was laminated at room temperature (23°C), thereby preparing a sample for measuring the surface peeling force consisting of an adhesive sheet on which the components were placed and supported by an annular frame.

[0196] (Surface peeling force before extension)

[0197] The obtained sample for measuring surface peel force was pressed against the component with a needle through the PSA sheet using a push-pull force meter (manufactured by Aikoh Engineering Co., Ltd., product name "RX-5"), and the force required to peel the component from the PSA sheet was read from the push-pull force meter as the surface peel force.

[0198] (Surface peeling force after extension)

[0199] The obtained surface peel strength measurement sample was placed on a Fig. 8A and Figure 8B The stretching device of the mechanism shown in the figure is used to push down the annular frame at a speed of 1 mm / sec and a pull-down amount of 5 mm and 10 mm under the condition that the element is supported by the adhesive sheet base 310. After the push-down, a push-pull force gauge (manufactured by Aikoh Engineering Co., Ltd., product name "RX-5") is used to push the element up through the adhesive sheet with a needle, and the force required to peel the element from the adhesive sheet is read from the push-pull force gauge, which is set as the surface peeling force.

[0200] Table 1 shows the evaluation results of the shear storage modulus and the surface peeling force of Examples 1 and 2 and Comparative Examples 1 and 2.

[0201]

[0202] In the adhesive sheet of Example 1 and Example 2 in which the adhesive layer is provided with concavoconvex, by setting the pull-down amount to an extension of 5mm, the surface peeling force decreases, and by setting the pull-down amount to an extension of 10mm, the surface peeling force further decreases, so it is known that the element can be easily peeled. On the other hand, in the adhesive sheet of Comparative Example 1 and Comparative Example 2 in which the adhesive layer is not provided with concavoconvex, the extension of the pull-down amount to 5mm and the extension of 10mm are almost not confirmed to facilitate the peeling of the element. As described above, it is confirmed that the number of convex portions that the adhesive layer contacts the element by being set to the extension of the adhesive sheet is reduced, and the bonding area of ​​the adhesive layer and the element will be reduced, which can help to reduce the surface peeling force. According to the facilitation of this element peeling, the external stimulation for picking up by the pushing or energy imparting of the needle can be omitted when peeling the element, thereby reducing the damage to the element and other parts.

[0203] As mentioned above, although embodiment of the invention was described, the invention is not limited to the said embodiment, Various changes and modifications can be made within the scope of the summary of the invention.

[0204] This application claims priority based on Japanese patent applications No. 2022-151756 filed on September 22, 2022, No. 2022-151757 filed on September 22, 2022, No. 2023-058459 filed on March 31, 2023, No. 2023-058460 filed on March 31, 2023, No. 2023-058462 filed on March 31, 2023, and No. 2023-058463 filed on March 31, 2023, and all the contents of which are incorporated herein by reference.

[0205] Description of reference numerals:

[0206] 110: adhesive layer;

[0207] 111: convex part;

[0208] 120: base material;

[0209] 130: holding the substrate;

[0210] 140a, 140b, 140c, 140d: components;

[0211] 150: adhesive sheet;

[0212] 310: base;

[0213] 320: Ring frame;

[0214] 510: peeling layer;

[0215] 511: convex part;

[0216] 520: Base material

Claims

1. A method for peeling an object from an adhesive sheet, the method comprising: An extending step of extending the adhesive sheet having an adhesive layer with a concavoconvex surface and holding an object on the adhesive layer in a surface direction; as well as The peeling step is to peel the object from the adhesive layer of the adhesive sheet after the adhesive layer is extended in the surface direction.

2. The stripping method according to claim 1, wherein: The peeled object is transferred to a transfer destination different from the pressure-sensitive adhesive sheet.

3. The stripping method according to claim 2, wherein: The peeling step is performed by bringing the object held by the pressure-sensitive adhesive sheet extended in the plane direction into contact with the transfer destination, and pulling the transfer destination away from the pressure-sensitive adhesive sheet without applying an external stimulus to the pressure-sensitive adhesive sheet.

4. The stripping method according to claim 1, wherein: The adhesive sheet further comprises a substrate supporting the adhesive layer. The tensile modulus of the substrate is 2500 MPa or less.

5. The stripping method according to claim 4, wherein: The elongation at break of the substrate is greater than 105%.

6. The stripping method according to claim 4, wherein: The substrate is a polyolefin film or a vinyl chloride copolymer film.

7. The stripping method according to claim 1, wherein: In the stretching step, the adhesive sheet is stretched by 1% or more in a surface direction.

8. The stripping method according to claim 1, wherein: The adhesive layer has a plurality of convex portions which are bounded by concave portions and spaced apart from each other, A pitch of the plurality of convex portions in the adhesive sheet before the stretching is greater than or equal to 1 μm and less than or equal to 100 μm.

9. The stripping method according to claim 8, wherein: The pitch of the protrusions after stretching in the adhesive sheet is 1.05 times or more the pitch of the protrusions before stretching.

10. The stripping method according to claim 1, wherein: In the extending step, the adhesive sheet is extended by displacing the inner side of the peripheral portion in the thickness direction of the adhesive sheet while fixing the peripheral portion of the adhesive sheet.

11. The stripping method according to claim 1, wherein: The adhesive layer is formed of an adhesive composition including an energy ray-curable compound.

12. The stripping method according to claim 1, wherein: The shear storage modulus of the adhesive layer is 0.001 MPa or more and 100 MPa or less.

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