Adhesive sheet and method for manufacturing electronic component or semiconductor device

Abstract

Provided is an adhesive sheet which is provided with an adhesive layer that captures elements that are separated from a holding substrate, said adhesive layer having protrusions and depressions on the surface thereof, and having a complex shear elastic modulus at 23 DEG C of 0.001-1.0 MPa (inclusive).

Description

Technical Field

[0001] The present invention relates to an adhesive sheet and an electronic component or a semiconductor device. Background Art

[0002] Elements used in electronic components or semiconductor devices are often formed in large quantities at once to obtain a plurality of elements. For example, a semiconductor chip is obtained by dicing a semiconductor wafer attached to an adhesive. When such a semiconductor chip is mounted on a semiconductor device, the semiconductor chip is often transferred. For example, Patent Document 1 discloses a method for transferring a semiconductor chip by irradiating a semiconductor chip with laser (laser lift-off method).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-141181 Summary of the invention

[0006] Problems to be solved by the invention

[0007] When the component moves from the substrate before transfer to the substrate after transfer, the component is held on the substrate after transfer. In recent years, the miniaturization of semiconductor devices and components has continued to develop, and the deviation of the transfer position may hinder further miniaturization, so the component is required to be firmly held on the substrate after transfer. On the other hand, the component held on the substrate after transfer is picked up from the substrate after transfer after a prescribed process. Therefore, for the component after the prescribed process, the component is required to be weakly held on the substrate after transfer so that it can be easily picked up from the substrate after transfer.

[0008] An object of the present invention is to provide a pressure-sensitive adhesive sheet capable of changing the holding property of a component.

[0009] Solutions for solving problems

[0010] After intensive research, the inventors of the present invention found that the above-mentioned problems can be solved by providing projections and depressions having a predetermined complex shear modulus on the surface of the adhesive sheet of the retaining element, and further repeated various studies to complete the present invention.

[0011] That is, the present invention relates to the following [1] to

[11] .

[0012] [1] An adhesive sheet comprising an adhesive layer for capturing an element separated from a holding substrate,

[0013] The adhesive layer has irregularities on its surface and has a complex shear modulus of elasticity of 0.001 MPa to 1.0 MPa at 23°C.

[0014] [2] The adhesive sheet according to [1], wherein the adhesive layer has a plurality of convex portions on its surface which are separated from each other by boundaries defined by concave portions,

[0015] The plurality of convex portions are deformed by being pressed when capturing the element, and the deformed plurality of convex portions are restored to a convex shape by an external stimulus.

[0016] [3] The adhesive sheet according to [1] or [2], wherein the adhesive layer has a plurality of convex portions on its surface which are separated from each other by boundaries defined by concave portions,

[0017] The height of the plurality of protrusions is greater than 1 µm.

[0018] [4] The adhesive sheet according to any one of [1] to [3], wherein the adhesive layer is formed from an adhesive composition containing an energy ray-curable compound (B).

[0019] [5] The pressure-sensitive adhesive sheet according to any one of [1] to [4], wherein the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing an acrylic resin (A).

[0020] [6] The pressure-sensitive adhesive sheet according to any one of [1] to [5], wherein the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition comprising an acrylic resin (A) and an energy-ray-curable compound (B).

[0021] [7] The adhesive sheet according to any one of [1] to [6], wherein the adhesive layer has a plurality of convex portions on its surface which are separated from each other by boundaries defined by concave portions,

[0022] The pitch of the plurality of protrusions is greater than or equal to 1µm and less than or equal to 100µm.

[0023] [8] The adhesive sheet according to any one of [1] to [7], wherein the adhesive layer has a plurality of convex portions on its surface which are separated from each other and are bounded by concave portions,

[0024] The area of ​​each of the plurality of protrusions is 10 μm 2 Above and 2000µm 2 the following.

[0025] [9] The adhesive sheet according to any one of [1] to [8], wherein the adhesive layer has a plurality of convex portions on its surface which are separated from each other by boundaries defined by concave portions,

[0026] A ratio of an area occupied by the convex portion to an area of ​​the adhesive layer is 1% or more and 95% or less.

[0027]

[10] The adhesive sheet according to any one of [1] to [9], wherein the adhesive layer is configured such that a ratio of a bonding area between the adhesive layer and one of the elements to an area of ​​one of the elements is 1% to 95%.

[0028]

[11] A method for manufacturing an electronic component or a semiconductor device, comprising the following steps:

[0029] A step of separating a component adhered to a holding substrate from the holding substrate due to an external stimulus;

[0030] A step of pressing the element separated from the holding substrate against the adhesive sheet described in any one of [1] to

[10] to deform a plurality of convex portions separated from each other and bounded by concave portions on the surface of the adhesive layer, thereby holding the element on the adhesive layer; and

[0031] The deformed plurality of convex portions are restored to a convex shape by an external stimulus, thereby accelerating the separation of the element from the adhesive sheet.

[0032] Effects of the Invention

[0033] According to the present invention, a pressure-sensitive adhesive sheet capable of changing the holding property of a component can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] 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.

[0035] Figure 1 This is a schematic diagram of a pressure-sensitive adhesive sheet according to one embodiment.

[0036] Figure 2A This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0037] Figure 2B This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0038] Figure 2C This is a plan view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0039] Figure 3A This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0040] Figure 3B This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0041] Figure 3C This is a cross-sectional view showing an example of the concavities and convexities of the pressure-sensitive adhesive sheet.

[0042] Figure 4 This is a flowchart of a method for manufacturing an electronic component or a semiconductor device according to one embodiment.

[0043] Figure 5A This is a schematic diagram for explaining the separation and capture of components.

[0044] Figure 5B This is a schematic diagram for explaining the separation and capture of components.

[0045] Figure 5C This is a schematic diagram for explaining the separation and capture of components.

[0046] Fig. 6A This is a schematic diagram for explaining the holding of components.

[0047] Figure 6B This is a schematic diagram for explaining the holding of components.

[0048] Fig. 7A This is a schematic diagram for explaining the restoration of components.

[0049] Figure 7B This is a schematic diagram for explaining the restoration of components.

[0050] Fig. 8A This is a schematic diagram of an adhesive sheet provided on the expansion device.

[0051] Figure 8B This is a schematic diagram of an adhesive sheet provided on the expansion device. DETAILED DESCRIPTION

[0052] 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 claims, 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 may be combined arbitrarily. In addition, the same figure mark is marked for the same or similar structure, and repeated description is omitted.

[0053] (definition)

[0054] 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.

[0055] In this specification, "electronic components" include all components used in electronic engineering and electrical engineering, and all components constituting electronic equipment. "Electronic components" can be formed by any one of semiconductors, conductors and / or insulators or by a combination of these. As "electronic components", for example, active components (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 components (such as wiring components, 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, sub-millimeter light-emitting diodes, power devices, MEMS (Micro Electro Mechanical Systems, micro-electromechanical systems), and control chips can be listed.

[0056] 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 limits and upper limits and combinations thereof are recorded. For example, the description 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.

[0057] <<Adhesive Sheet of the Present Embodiment>>

[0058] The adhesive sheet of the present embodiment includes an adhesive layer for capturing an element separated from a holding substrate, and the adhesive layer has irregularities on its surface. Figure 1 A schematic diagram showing an adhesive sheet according to an embodiment. In one embodiment, the adhesive sheet may include an adhesive layer 110 and a substrate 120. However, the adhesive sheet does not necessarily have a 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 may be used. The following describes the various components of the adhesive sheet.

[0059] <Adhesive layer>

[0060] 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.

[0061] (Complex shear modulus of elasticity)

[0062] The adhesive layer 110 of the present embodiment has a complex shear modulus of elasticity of more than 0.001 MPa and less than 1.0 MPa at 23°C. The complex shear modulus of elasticity can preferably be set to less than 1.0 MPa, more preferably less than 0.8 MPa, further preferably less than 0.6 MPa, and particularly preferably less than 0.3 MPa. Thus, when the element is held on the adhesive sheet, the convex portion can be pressed by the element and deformed and flattened. In addition, as the convex portion is deformed and flattened, the concave portion of the adhesive layer 110 bulges, and the convex portion and the concave portion are in contact with the element. Thus, the element is in planar contact with the adhesive layer 110, so the element is firmly held on the adhesive layer 110.

[0063] The complex shear elastic modulus can be preferably set to 0.001MPa or more, more preferably 0.01MPa or more, further preferably 0.05MPa or more, and particularly preferably 0.1MPa or more. Thus, when picking up the component from the adhesive sheet, the deformed convex portion can be restored to a convex shape by applying an external stimulus to the adhesive sheet. In addition, the deformed convex portion is restored to a convex shape, and the deformed concave portion is restored to a concave shape, and the convex portion is in point contact with the component, so the component is weakly held in the adhesive layer 110. As a result, it is easy to pick up the component from the adhesive sheet.

[0064] The complex shear modulus is preferably within a range of 0.001 MPa to 1.0 MPa, more preferably 0.01 MPa to 0.8 MPa, further preferably 0.05 MPa to 0.6 MPa, and particularly preferably 0.1 MPa to 0.3 MPa. Thus, the adhesive sheet of this embodiment can change the holding property of the element.

[0065] The complex shear modulus of the adhesive layer 110 can be confirmed, for example, in the following manner. A sample with a diameter of 8 mm and a thickness of 1 mm is prepared, and the complex shear modulus of the sample at 23° C. is measured by a torsional shear method using a viscoelasticity measuring device at a frequency of 1 Hz, thereby measuring the complex shear modulus of the adhesive layer 110. A more specific method for measuring the complex shear modulus will be described in the examples.

[0066] (shape)

[0067] The surface of the adhesive layer 110 has projections and depressions. If projections and depressions having a predetermined complex shear modulus exist on the surface of the adhesive layer 110, the holding properties between the element and the adhesive layer 110 can be changed. Therefore, the specific shape of the projections and depressions on the surface of the adhesive layer 110 is not limited.

[0068] In one embodiment, the adhesive layer 110 has a plurality of convex portions separated from each other by concave portions on its surface. Each of the plurality of convex portions may be separated by a concave portion that is continuous across the entire adhesive layer 110. By providing a continuous concave portion around such a convex portion, the holding property of the element may be changed.

[0069] On the other hand, the gas compressed between the element and the adhesive layer 110 generated by the element approaching the adhesive layer 110 can escape to the concave portion of the adhesive sheet, thereby relieving the pressure generated between the element and the adhesive layer 110. Therefore, the displacement of the holding position of the element on the adhesive sheet due to the pressure generated between the element and the adhesive layer 110 can be suppressed. In one embodiment, the concave portion located around each of the plurality of convex portions is continuous to the end of the adhesive layer 110. In this way, by providing a concave portion continuous to the end of the adhesive layer 110, the air compressed between the element and the convex portion of the adhesive layer 110 can be efficiently escaped to the outside of the element. FIG. 2A to FIG. 2C 1 is a plan view showing the shape of such an adhesive layer 110 .

[0070] like Figure 2A As shown in FIG. 1 , the convex portions 111 may be 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 fixed intervals. Figure 2B As shown, the protrusions 111 can also be arranged in a manner with regularly varying intervals. Figure 2B In the example of , the intervals between the convex portions 111 in the center of the adhesive sheet are shortened, and the intervals between the convex portions 111 in the peripheral portion of the adhesive sheet are lengthened. According to this configuration, the retention of the adhesive sheet can be improved, and the compressed air can be efficiently released from the peripheral portion of the element through the wider concave portion. Moreover, the convex portions 111 can also be arranged irregularly.

[0071] Figure 2C is a top view showing other shapes of the adhesive layer 110. Figure 2C As shown, stripe-shaped protrusions 111 may be provided on the surface of the adhesive layer 110 . Figure 2C In the embodiment, linear protrusions 111 having a certain width are arranged at fixed intervals. Figure 2B Likewise, the width or interval of the linear protrusions 111 may vary regularly, or the linear protrusions 111 may be arranged irregularly.

[0072] It should be noted that if Figure 2BAs shown, the minimum interval among all the convex portions 111 in the central portion of the adhesive sheet may be shorter than the minimum interval among all the convex portions 111 in the peripheral portion of the adhesive sheet. Here, the central portion is, for example, a circular region having 1 / 4 of the area of ​​the adhesive sheet and centered at the center of gravity of the adhesive sheet, and the peripheral portion is, for example, all regions other than the central portion of the adhesive sheet.

[0073] From the viewpoint of adjusting the retention, the pitch P of the protrusion 111 is preferably greater than 1µm, more preferably greater than 5µm, further preferably greater than 10µm, and particularly 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 retention force, the pitch is preferably less than 100µm, more preferably less than 75µm, more preferably less than 50µm, further preferably less than 35µm, and particularly preferably less than 25µm. Here, the pitch of the protrusion 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, Figure 2A In the case of , the pitch of the convex portion 111 means 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 multiple straight lines, the pitch means the distance between the center points of the convex portions on the straight line arranged with the shortest pitch. In addition, for example, Figure 2C When the convex portion is generally elongated and it is difficult to identify the center point of the convex portion, the distance from the boundary of the convex portion 111 on the same side to the boundary of another convex portion 111 ′ that is closest to the convex portion 111 ′ is indicated.

[0074] 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 an inclination.

[0075] Figure 3A 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 3A The convex portion 111 shown in the figure has an inclination, that is, the front end of the convex portion 111 becomes thinner. Figure 3A 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 separated from each other and defined by the concave portion.

[0076] In addition, if Figure 3BAs shown, the front end of the convex portion 111 may be a curved surface such as a hemispherical shape or a part of a sphere. 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 in a manner that does not cause deviation. On the other hand, the front end of the convex portion may also be a flat surface.

[0077] In addition, the convex portion 111 may be Figure 3C As shown, it is in a T-shape. As another example, the convex portion 111 may be in the shape of a plurality of particle collections, mushroom-shaped, lotus leaf-shaped, or needle-shaped. As a further other example, the surface of the adhesive layer 110 may be rough or fibrous, and it can be said that such a surface may also have concavoconvexity.

[0078] The width or diameter of each convex portion 111 is the width or diameter of the base portion rather than the front end portion, and is preferably 1µm or more, more preferably 2µm or more, further preferably 5µm or more, and particularly preferably 10µm or more. On the other hand, it is preferably 100µm or less, more preferably 50µm or less, further preferably 30µm or less, and particularly preferably 20µm or less. Thus, the retention 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 tangent to the two sides of the convex portion 111 on the surface of the concave portion ( Figure 3A Indicated by D).

[0079] In addition, the area of ​​each convex portion 111 is preferably 10 μm 2 More than 20µm is more preferred 2 More preferably, 30µm 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 3A In this case, it is the area of ​​a circle with diameter D).

[0080] 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 retention of the element can be changed. Here, the height of the convex portion 111 is Figure 3A Indicated by H.

[0081] In addition, the area of ​​each convex portion 111 is preferably 1% or more, more preferably 5% or more, more preferably 10% or more, further preferably 18% or more, and particularly preferably 40% or more relative to the area of ​​the adhesive layer 110. On the other hand, the area of ​​each convex portion is preferably 95% or less, more preferably 75% or less, and further preferably 60% or less relative to the area of ​​the adhesive layer 110. Thus, the retention of the element can be changed.

[0082] The concavoconvexity 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 between the adhesive layer 110 and an element to the area of ​​the element is preferably 1% or more relative to 100% of the area of ​​the element, more preferably 2% or more, more preferably 3% or more, more preferably 4% or more, more preferably 5% or more, more preferably 7% or more, and particularly preferably 10% or more. On the other hand, the ratio of the bonding area between the adhesive layer 110 and an element to the area of ​​the element is preferably 95% or less, more preferably 70% or less, more preferably 50% or less, and particularly preferably 30% or less. Figure 3A In the case of, the bonding area is equivalent to the area of ​​a circle with a diameter T. It should be noted that when the capture position of the element on the adhesive sheet is offset, the bonding area may change. In this case, regardless of the capture position of the element, the bonding area ratio can fall within the above range.

[0083] (Composition of Adhesive Layer (Adhesive Composition))

[0084] 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 listed. 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 listed. The adhesive composition forming the adhesive layer 110 can include a copolymer with two or more structural units. The form of this copolymer is not particularly limited, and 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 a resin or can be composed of two or more resins.

[0085] 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 with a mass average molecular weight (Mw) of more than 10,000. From the viewpoint of improving adhesion, the mass average molecular weight (Mw) of the resin is preferably more than 10,000, more preferably more than 70,000, and more preferably more than 140,000. In addition, from the viewpoint of suppressing the complex shear elastic modulus to be below the specified value, the Mw is preferably less than 2 million, more preferably less than 1.2 million, and more preferably less than 900,000. In addition, from the viewpoint of improving adhesion, the number average molecular weight (Mn) of the resin is preferably more than 10,000, more preferably more than 50,000, and more preferably more than 100,000. In addition, from the viewpoint of suppressing the complex shear elastic modulus to be below the specified value, the Mn is preferably less than 2 million, more preferably less than 1 million, and more preferably less than 700,000. As described below, 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 a crosslinking reaction occurs by energy application.

[0086] 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 complex shear modulus of the obtained adhesive layer can be easily set within the range described below.

[0087] The amount of resin relative to the total amount of components constituting the adhesive composition that forms the adhesive layer 110 can be appropriately set according to the required adhesive strength and complex shear modulus of the adhesive layer 110, and is preferably 30 mass % or more, more preferably 40 mass % or more, more preferably 50 mass % or more, further preferably 55 mass % or more, particularly preferably 60 mass % or more, and is preferably 99.99 mass % or less, more preferably 99.95 mass % or less, further preferably 99.90 mass % or less.

[0088] Thermoplastic resin

[0089] 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 by a thermoplastic resin. When a thermoplastic resin is used, the resin is softened by heating, and it is easy to form a concavoconvex shape in the adhesive layer 110, and it is easy to maintain the concavoconvex shape formed by cooling the resin. As examples of thermoplastic resins, rubber resins, acrylic resins, urethane resins, and olefin resins can be listed. 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.

[0090] Acrylic resin (A)

[0091] In one embodiment, the thermoplastic resin may be an acrylic resin (A). From the viewpoint of improving adhesive strength, the mass average molecular weight (Mw) of the acrylic resin (A) is preferably 10,000 or more, more preferably 100,000 or more, and further preferably 500,000 or more. In addition, from the viewpoint of suppressing the complex shear elastic modulus to be below a specified value, it is preferably 2,000,000 or less, more preferably 1,500,000 or less, and further preferably 1,000,000 or less.

[0092] The glass transition temperature (Tg) of the acrylic resin (A) is preferably -75°C or higher, more preferably -70°C or higher, and preferably 5°C or lower, more preferably -25°C or lower, and further preferably -55°C or lower. By setting Tg within this range, it is easy to set the complex shear modulus of the obtained adhesive within this range.

[0093] When the acrylic resin (A) has two or more structural units, the glass transition temperature (Tg) of the acrylic resin (A) can be calculated using the Fox equation. The Tg of the monomer from which the structural unit is derived can be the value described in the polymer data handbook or the adhesive handbook.

[0094] Examples of the (meth)acrylic acid ester constituting the acrylic resin (A) 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, and stearyl (meth)acrylate. (Meth)acrylic acid alkyl esters whose alkyl group is a chain structure with 1 to 18 carbon atoms; (meth)acrylic acid cycloalkyl esters such as isobornyl (meth)acrylate and dicyclopentanyl (meth)acrylate; (meth)acrylic acid aralkyl esters such as benzyl (meth)acrylate; (meth)acrylic acid cycloalkenyl esters such as dicyclopentenyl (meth)acrylate; (meth)acrylic acid cycloalkenyloxyalkyl esters such as dicyclopentenyloxyethyl (meth)acrylate; (meth)acrylic acid imidoyl esters; (meth)acrylic acid esters containing glycidyl group such as glycidyl (meth)acrylate; (meth)acrylic acid esters containing hydroxyl group such as 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; (meth)acrylic acid esters containing substituted amino group such as N-methylaminoethyl (meth)acrylate, etc. 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.

[0095] The acrylic resin (A) 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.

[0096] The monomers constituting the acrylic resin (A) 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.

[0097] The acrylic resin (A) may have a functional group that can bond 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 (A), may bond to other compounds via a crosslinking agent (C) described later, or may directly bond to other compounds without the crosslinking agent (C).

[0098] The amount of acrylic resin (A) in the total amount of resin in the adhesive composition can be appropriately set according to the required adhesive strength and complex shear 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, particularly preferably 50% by mass or more, and preferably 100% by mass or less, more preferably 95% by mass or less.

[0099] Energy ray curable resin (B)

[0100] In one embodiment, the resin contained in the adhesive composition forming the adhesive layer 110 may contain an energy-ray curable resin (B). "Energy-ray curability" refers to the property of curing by irradiating energy rays, and the energy-ray curable resin (B) refers to a resin that is cured by irradiating energy rays. In addition, "energy rays" refer to rays with energy quanta in electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays, radiation, electron beams, etc. Ultraviolet rays can be irradiated, for example, by using an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, UV-LED (Ultraviolet Light Emitting Diode, ultraviolet light emitting diode), etc. as an ultraviolet source. The electron beam can irradiate an electron beam generated by an electron beam accelerator, etc. In addition, "energy-ray polymerizability" refers to the property of polymerizing by irradiating energy rays.

[0101] When such an energy-beam-curable resin (B) is used, the formed concavo-convex shape can be easily maintained by applying energy (for example, irradiating with energy beams) after the concavo-convex shape is formed on the resin.

[0102] As the energy-ray curable resin (B), monomers, oligomers and polymers into which polymerizable functional groups are introduced can be used. The polymerizable functional group refers to a functional group that is cross-linked by the addition 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.

[0103] From the viewpoint of improving adhesive force, the mass average molecular weight (Mw) of the energy-ray curable resin (B) is preferably 100 or more, more preferably 150 or more. Furthermore, from the viewpoint of suppressing the complex shear modulus to be below a predetermined value, the mass average molecular weight (Mw) of the energy-ray curable resin (B) is preferably 2 million or less, more preferably 1 million or less, and further preferably 200,000 or less.

[0104] When a monomer or oligomer is used as the energy-ray curable resin (B), from the viewpoint of polymerizability, the number average molecular weight (Mn) of the energy-ray curable resin (B) is preferably 100 or more, and more preferably 150 or more. Furthermore, from the viewpoint of suppressing the complex shear modulus to be below a predetermined value, the number average molecular weight (Mn) of the energy-ray curable resin (B) is preferably 5000 or less, more preferably 1000 or less, and further preferably 500 or less.

[0105] When a polymer is used as the energy-ray curable resin (B), from the viewpoint of improving the adhesive force, the mass average molecular weight (Mw) of the energy-ray curable resin (B) 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 complex shear elastic modulus to be below a specified value, the mass average molecular weight (Mw) of the energy-ray curable resin (B) is preferably 2,000,000 or less, more preferably 500,000 or less, and further preferably 300,000 or less.

[0106] 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 (B) 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.

[0107] In one embodiment, as the energy-ray curable resin (B), a monomer or oligomer having a polymerizable functional group can be used. As such an energy-ray curable compound, for example, poly (meth)acrylate monomers such as glycerol di(meth)acrylate, glycerol tri(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol (meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, etc. can be listed; urethane (meth)acrylate; polyester (meth)acrylate; polyether (meth)acrylate; epoxy (meth)acrylate, etc. Among them, from the perspective of maintaining the concavo-convex shape formed, glycerol di(meth)acrylate, glycerol tri(meth)acrylate, and tricyclodecane dimethanol di(meth)acrylate can be preferably listed.

[0108] In one embodiment, as the energy-ray curable resin (B), 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 specific examples of diene rubbers, polymers using butadiene or isoprene as monomers (i.e., having butadiene or pentadiene as structural units) can be listed. In one embodiment, as the energy-ray curable resin (B), polybutadiene resin (PB resin), styrene-butadiene-styrene block copolymer (SBS resin), and styrene-isoprene-styrene block copolymer can be listed.

[0109] The amount of the energy-ray-curable resin (B) in the total amount of resin in the adhesive composition can be appropriately set according to the required adhesion and complex shear 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, particularly 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 particularly preferably 60% by mass or less.

[0110] In addition, in one embodiment, the adhesive composition may contain an acrylic resin (A) and an energy-ray curable resin (B). The relationship between the content of the acrylic resin (A) and the energy-ray curable resin (B) can be appropriately set according to the required adhesive force and complex shear elastic modulus of the adhesive layer 110. In one embodiment, the content of the acrylic resin (A) in the total content of the acrylic resin (A) and the energy-ray curable resin (B) is preferably 0% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, particularly preferably 50% by mass or more, and preferably 100% by mass or less, more preferably 95% by mass or less.

[0111] 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.

[0112] Crosslinking agent (C)

[0113] The adhesive composition may also contain a crosslinking agent (C) for bonding and crosslinking the functional groups of the resin with other compounds. 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)-aziridine]triphosphine triazine, metal chelate crosslinking agents (crosslinking agents having a metal chelate structure) such as aluminum chelates, and isocyanurate crosslinking agents (crosslinking agents having an isocyanuric acid skeleton), etc.

[0114] 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, further preferably 1% by mass or more, and preferably 5% by mass or less, more preferably 4% by mass or less, further preferably 2% by mass or less.

[0115] Photopolymerization initiator (D)

[0116] The adhesive composition may also include a photopolymerization initiator (D) that initiates a crosslinking reaction by applying energy (e.g., irradiation with energy rays). When the adhesive composition includes an energy-curable resin (B), the adhesive layer 110 further includes a photopolymerization initiator (D), so that the crosslinking reaction proceeds even when relatively low energy is applied.

[0117] 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, dibenzyl, diacetyl, 8-chloroanthraquinone, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0118] 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.

[0119] Antioxidant (E)

[0120] 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, sulfur antioxidants, and phosphorus antioxidants such as phosphate antioxidant compounds.

[0121] 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.

[0122] <Base Material>

[0123] 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 peelability, facilitating lamination, or being able to be made into a roll form, the substrate 120 may be a soft substrate. As the substrate 120, for example, a resin film may be used.

[0124] The resin film is a film using a resin material as a main material, and may be formed of the resin material alone or may contain additives in addition to the resin material. The resin film may also have laser transparency.

[0125] Specific examples of resin films include: 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-(meth)acrylic acid copolymer films, and ethylene-(meth)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.

[0126] From the perspective of versatility, relatively high strength and easy prevention of warping, and heat resistance, the resin film can be set as 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.

[0127] The thickness of the substrate 120 is not particularly limited. From the perspective of both support and rollability, it is preferably 10 µm or more, more preferably 25 µm or more, and more preferably 40 µm or more, and preferably 500 µm or less, more preferably 200 µm or less, and more preferably 90 µm or less. The thickness of the substrate 120 can preferably be set in the range of 10 µm or more and 500 µm or less, preferably 25 µm or more and 200 µm or less, and more preferably 40 µm or more and 90 µm or less.

[0128] <Other layers>

[0129] The adhesive sheet may also have a layer other than the substrate 120 and the adhesive layer 110. For example, an adhesive layer may be further provided on the surface of the substrate 120 on the opposite side to the adhesive layer 110. The adhesive sheet may be attached to other substrates such as quartz glass via such an adhesive layer. The type of the further provided adhesive layer is not particularly limited, and for example, a conventional adhesive may be used to form the further provided adhesive layer.

[0130] <Method for producing adhesive sheet>

[0131] There is no particular restriction on the method for manufacturing the adhesive sheet. 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.

[0132] 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).

[0133] The processing of setting concavoconvex on the surface of the adhesive layer is also not particularly limited. 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 on the surface. Specifically, the adhesive layer provided on the adhesive sheet substrate can be pressed by the mold while the adhesive layer is heated, so as to set concavoconvex on the surface of the adhesive layer. As a more specific method, the adhesive layer can be pressed by the 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 the adhesive layer is heated, 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 using a mold to press the adhesive layer, a method for vacuum laminating the adhesive layer provided on the adhesive sheet substrate and the mold can be cited. It should be noted that the adhesive layer 110 having the surface irregularities may be formed on the adhesive sheet substrate 120 in a single step, instead of performing the two-step steps of forming the adhesive layer and forming the irregularities.

[0134] As another method, the adhesive layer 110 having a concavo-convex shape can be provided by spraying a solution of the adhesive composition. In addition, a filler can be added to the solution of the adhesive composition and the solution can be applied to provide the adhesive layer 110 having a rough surface or a fibrous surface. As a further other method, the adhesive layer having a concavo-convex shape can be directly provided on the substrate by applying the solution of the adhesive composition in a desired pattern using a printing method such as an inkjet method.

[0135] In addition, the adhesive sheet without substrate 120 can be made by forming the adhesive composition into a sheet. Moreover, the adhesive layer can also be formed by applying the liquid adhesive containing the adhesive composition to any object. In these cases, the surface of the adhesive layer can be provided with a concavo-convex treatment after the adhesive layer is formed, and the adhesive layer can also be formed by a method for forming concavo-convex on the surface.

[0136] <<Method for Manufacturing Electronic Components or Semiconductor Devices Using Adhesive Sheet of the Present Embodiment>>

[0137] The adhesive sheet of the present embodiment as described above can be used to hold a component 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 component is used to manufacture electronic components or semiconductor devices. That is, this adhesive sheet can be used to manufacture electronic components or semiconductor devices.

[0138] The manufacturing method of the electronic component or semiconductor device of the present embodiment includes the following steps: a step of separating the element from the holding substrate; a step of deforming the convex portion of the adhesive layer to hold the element on the adhesive sheet; and a step of 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 4 Flowchart of FIG. 5A to FIG. 5C A schematic diagram illustrating the separation and capture of components, Fig. 6A and Figure 6B A schematic diagram illustrating the retention of components, and Fig. 7A and Figure 7B The restoration of the convex portion is described in detail with reference to a schematic diagram.

[0139] (S10: Preparation of the substrate)

[0140] exist Figure 4 In the step S10 shown, a holding substrate with components attached thereto is prepared. The type of component is not particularly limited. The component may be, for example, a semiconductor chip such as an LED chip, a semiconductor chip with a protective film, a semiconductor chip with a die-attaching film (DAF), etc. In addition, the component may be a micro light-emitting diode, a sub-millimeter light-emitting diode, a power device, a MEMS (MicroElectro Mechanical Systems), or a control chip, or a component thereof. In addition, the component may be a monolithic object such as a wafer, a panel, or a substrate. For example, the component may also have a circuit surface, which is formed with an integrated circuit having circuit elements such as transistors, resistors, and capacitors. In addition, the component is not necessarily limited to a monolithic object, but may also be various wafers or various substrates that are not monolithic.

[0141] The size of the element is not particularly limited. For example, the size of the element may be preferably 100 μm. 2 More than 500µm 2 More preferably, 1000µm 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.

[0142] 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 rectangle such as a square or a rectangle.

[0143] As the panel, a fan-out semiconductor package (such as FOWLP (Fan Out Wafer Level Package: fan-out wafer level package) or FOPLP (Fan-out Panel Level Package: fan-out panel level package)) 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 rectangular substrate of about 300mm to 700mm.

[0144] Examples of the substrate include a glass substrate, a sapphire substrate, and a compound semiconductor substrate.

[0145] 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.

[0146] The method for preparing the holding substrate for holding the element is also not particularly limited. For example, a semiconductor wafer may be attached to the holding substrate, and then the semiconductor wafer may be cut. Thus, by cutting the semiconductor wafer, the element may be obtained, and thus the holding substrate with the element attached thereto may be obtained.

[0147] 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 thereto. For example, after cutting the semiconductor wafer held on the wafer substrate, the obtained element is made to be in 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 process, the element can be transferred from the wafer substrate to the holding substrate.

[0148] It should be noted that, as described below, 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 holding the substrate may contain a laser absorbent. As the laser absorbent, for example, one or more selected from pigments and dyes can be listed.

[0149] (S20: Separation of components)

[0150] exist Figure 4 In step S20 shown, the element attached to the holding substrate is separated from the holding substrate due to external stimulation. Specifically, the element is relatively far away from the holding substrate. In addition, the element is relatively close to the adhesive sheet. Then, the element is separated from the holding substrate and captured by the adhesive sheet by contacting the adhesive layer of the adhesive sheet.

[0151] like Figure 5A As shown in FIG. 1 , the position (P1) on the adhesive sheet 150 is positioned so as to face the element 140a attached to the holding substrate 130, whereby the separated element 140a moves to the position (P1) on the adhesive sheet 150. Next, as shown in FIG. Figure 5B As shown, the component 140 a attached to the holding substrate 130 is separated from the holding substrate 130 by an external stimulus, and the component 140 b is captured by the adhesive sheet 150 .

[0152] Moreover, if Figure 5B As shown in FIG. 1 , the position (P2) on the adhesive sheet 150 is positioned so as to be opposite to the element 140b attached to the holding substrate 130, thereby the separated element 140b moves to the position (P2) on the adhesive sheet 150. Then, similarly to the element 140a, the element 140 attached to the holding substrate 130 is separated from the holding substrate 130 due to an external stimulus, and the element 140b is captured on the adhesive sheet 150.

[0153] As described above, the components are separated and captured while the relative positions of the substrate and the adhesive sheet in the plane direction are changed. Thus, the components can be positioned in a manner that the relative arrangement of the multiple components on the substrate is different from the relative arrangement of the multiple components on the adhesive sheet.

[0154] Furthermore, in another embodiment, Figure 5CAs shown, the relative positions of the holding substrate and the adhesive sheet in the plane direction are not changed, and the components 140a to 140d attached to the holding substrate 130 are separated from the holding substrate 130 due to the external stimulus, and the components 140a to 140d are captured by the adhesive sheet 150. At this time, the external stimulus may be applied to each component in turn or to all components simultaneously.

[0155] In addition, when using an adhesive sheet with a flat surface, the pressure generated between the component and the adhesive sheet may Figure 5A In the example of , the element 140a may be captured at a position offset from the position (P1). However, since the surface of the adhesive layer has projections and depressions, the pressure generated between the element and the adhesive layer is alleviated, making it easier to capture the element at a desired position of the adhesive sheet.

[0156] The type of external stimulus during element separation is not particularly limited, and examples thereof include energy imparting, cooling, extension of the holding substrate, and physical stimulation (for example, pressing the back of the holding substrate with 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 then the element can be separated from the holding substrate.

[0157] As a method of imparting energy, local heating, light irradiation, or hot ray irradiation can be listed. In addition, as a method of light irradiation, infrared irradiation, visible light irradiation, and laser irradiation can be listed. In one embodiment, laser irradiation is performed as an external stimulus, that is, the element is separated from the holding substrate by a laser stripping method. At this time, the laser is irradiated toward the pasting part of the specific element in the holding substrate. For example, the irradiation of such laser can be performed on 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, if the laser is absorbed by the adhesive layer, gas is generated by sublimation of at least a portion of the adhesive layer. As described above, by sublimation of at least a portion of the adhesive layer, the bonding area between the specific element and the adhesive layer is reduced, so the bonding force between the specific element and the holding substrate decreases. In addition, by the pressure of the generated gas, the bonding force between the specific element and the holding substrate will also decrease. As a result, the specific element is separated from the holding substrate.

[0158] 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.

[0159] (S30: Retention of components)

[0160] In step S30 , the element separated from the holding substrate is held on the adhesive sheet. Fig. 6A and Figure 6B Indicates Figure 5C Another embodiment of separating and capturing the components without changing the relative position of the substrate and the adhesive sheet in the plane direction is shown as an example of holding the components on the adhesive sheet. Fig. 6A As shown, the substrate 130 is used to cover Figure 5C As shown, a plurality of elements 140a to 140d are captured on the adhesive sheet 150, and the elements 140a to 140d are pressed against the adhesive sheet 150. In addition, the member for pressing the elements 140a to 140d against the adhesive sheet 150 may be other members instead of the holding substrate 130, for example, a rod-shaped, needle-shaped, spherical, plate-shaped, or other member may be used. In addition, it may be a member for pressing all the elements captured on the adhesive sheet 150, or it may be a member for pressing a part of the elements. In one embodiment, the laminated product of the elements 140a to 140d sandwiched between the adhesive sheet 150 and the holding substrate 130 may be passed through a laminator at a temperature of 0°C to 80°C and a pressure of 0.1 MPa to 1 MPa, so that the elements 140a to 140d are pressed or laminated against the adhesive sheet 150.

[0161] By pressing the components 140a to 140d onto the adhesive sheet 150, as Figure 6B As shown, the plurality of convex portions 111 of the adhesive layer are deformed, and the adhesive sheet 150 (adhesive layer) holds the elements 140a to 140d. In addition, as the convex portions 111 are deformed and flattened, the adhesive layer of the concave portions 112 bulges, and the convex portions 111 and the concave portions 112 contact the elements 140a to 140d. It should be noted that Figure 6B In the figure, for easy understanding, the raised portion 112a of the adhesive layer of the recessed portion 112 is shown separated from the raised portion 111, but the raised portion 111 is formed to be in contact with the raised portion 112a. Thus, the elements 140a to 140d are in planar contact with the adhesive layer, so the elements 140a to 140d are firmly held by the adhesive layer.

[0162] (S40: Component Processing)

[0163] exist Figure 4In the step S40 shown, a process for manufacturing an electronic component or a semiconductor device is performed using the element retained on the adhesive sheet. The process for manufacturing an electronic component or a semiconductor device is not particularly limited, and for example, the element retained on the adhesive sheet is transferred to a wiring substrate. Wiring connected to the element may also be provided on the wiring substrate. At this time, the position of each element on the wiring substrate has been 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. Afterwards, in the next step S50, the separation of the elements is promoted so that the elements are separated from the adhesive sheet.

[0164] (S50: Separation of components)

[0165] exist Figure 4 In step S50 shown in FIG. 1 , the components held on the adhesive sheet are separated due to external stimulation. Fig. 7A As shown, the components 140a to 140d are held on the adhesive sheet 150. By applying an external stimulus to the adhesive sheet 150, such as Figure 7B As shown, the deformed or flattened plurality of convex portions 111 are restored to a convex shape.

[0166] The type of external stimulus for promoting the separation of the components is not particularly limited, and the external stimulus used in step S20 can be used. In one embodiment, the extension of the adhesive sheet can be used as the external stimulus to restore the deformed or flattened convex portions 111 to a convex shape. For example, Fig. 7A In the process, the portion on the opposite side of the portion where the adhesive layer of the element is retained is arranged on a base (not shown), and the two ends of the adhesive sheet are pressed downward as indicated by the arrow (P3) at a temperature above -20° and below 80°C, thereby extending the adhesive sheet 150 and restoring the deformed or flattened multiple protrusions 111 to a convex shape.

[0167] In addition, the deformed convex portion 111 returns to a convex shape, the deformed or raised convex portion 112a returns to a concave shape, and the convex portion 111 contacts the elements 140a to 140d in a point-like manner. In other words, the elements 140a to 140d are peeled off from the raised portion 112a. As a result, the elements 140a to 140d are weakly held on the adhesive layer.

[0168] Next, the plurality of elements 140a to 140d are separated from the adhesive sheet 150. As described above, the elements 140a to 140d are weakly held by the adhesive layer and can therefore be easily picked up from the adhesive sheet. An electronic component or semiconductor device having an element (eg, a semiconductor element) can be manufactured in this order.

[0169] Example

[0170] The present invention is 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.

[0171] The following compounds were used in Examples and Comparative Examples.

[0172] ((A) ingredient)

[0173] Acrylic copolymer (A1): monomer ratio is 2-ethylhexyl acrylate / 2-hydroxyethyl acrylate / acrylic acid = 92.8 / 7.0 / 0.2, mass average molecular weight (Mw) is 1.1 million

[0174] (Component (B))

[0175] Energy beam curable resin (B1): manufactured by Toagosei Co., Ltd., product name: "Aronix M-920"

[0176] Energy-beam curable resin (B2): tricyclodecane dimethanol diacrylate

[0177] Energy-beam curable resin (B3): SBS having a vinyl group in the side chain (styrene-butadiene-styrene block copolymer 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, 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%, melt flow rate measured under the conditions of a temperature of 200° C. and a load of 5 kg of 5 g / 10 minutes])

[0178] Energy-beam curable resin (B4): PB having a vinyl group on the side chain (polybutadiene copolymer having a 1,2-vinyl group on the side chain [weight average molecular weight (Mw) of 5,500, glass transition temperature of -49°C, liquid at room temperature])

[0179] (Ingredient (C))

[0180] Crosslinking agent (C1): Isocyanurate-type polyisocyanate derived from hexamethylene diisocyanate

[0181] (Component (D))

[0182] Photopolymerization initiator (D1): 1-hydroxycyclohexyl phenyl ketone

[0183] Photopolymerization initiator (D2): 2,4,6-trimethylbenzoyldiphenylphosphine oxide

[0184] Photopolymerization initiator (D3): Bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide

[0185] (Ingredient (E))

[0186] Antioxidant (E1): A composition in which a hindered phenol antioxidant and a phosphorus antioxidant are mixed at a mass ratio of 1:1

[0187] (Example 1)

[0188] 100 parts by mass of an acrylate copolymer (A1), 5 parts by mass of an energy-ray curable resin (B1), 0.1 parts by mass of a crosslinking agent (C1), and 0.15 parts by mass of a photopolymerization initiator (D1) were dissolved in toluene to prepare an adhesive composition. The adhesive composition was applied to the release-treated surface of a release sheet (manufactured by Lintec Co., Ltd., product name "SP-PET382150"), and the obtained coating was dried at 100°C for 2 minutes to form an adhesive layer with a thickness of 25µm. A substrate (ethylene-methacrylic acid copolymer film, ethylene-methacrylic acid copolymer film, acid content 9% by mass, one side surface roughened by embossing, thickness 80µm) was bonded to the adhesive layer to prepare an adhesive sheet.

[0189] After the release sheet was peeled off, the adhesive layer of the adhesive sheet was attached to a replica mold with a concave shape formed in advance, and vacuum laminated at 60°C for 300 seconds. Then, an ultraviolet irradiator (manufactured by Heraeus) was used to irradiate the film at an illumination of 130 mW / cm 2 , light intensity 210mJ / cm 2 By irradiating with ultraviolet rays, a pressure-sensitive adhesive sheet having a concavo-convex shape on the surface is produced.

[0190] The concavo-convex shape of the adhesive layer of the adhesive sheet Figure 2A The columns are arranged in a grid pattern. The pitch (P) between the columns in the adhesive sheet is 20 μm. Figure 3A 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 adhesive layer and the bonding portion of the element to be captured (i.e., the area of ​​the front end of the convex portion) to the area of ​​the adhesive sheet is about 12.6%. It should be noted that the above-mentioned replica mold uses a surface shape that complements this concave and convex shape.

[0191] (Examples 2 to 6 and Comparative Examples 1 and 2)

[0192] PSA sheets of Examples 2 to 6 and Comparative Examples 1 and 2 were obtained in the same manner as in Example 1 except that the types and blending ratios of the components were changed as shown in Table 1.

[0193] (Complex shear modulus of elasticity)

[0194] An adhesive layer was formed from the adhesive composition obtained in Example 1, and an ultraviolet irradiator (manufactured by Heraeus) was used to irradiate the adhesive layer at an illuminance of 130 mW / cm 2 , light intensity 210mJ / 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 complex shear elastic modulus G* 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. In the same manner as in Example 1, an adhesive layer was prepared from the curable composition obtained in Examples 2 to 6 and Comparative Examples 1 and 2, and the complex shear elastic modulus G* of the adhesive layers of Examples 2 to 6 and Comparative Examples 1 to 2 was measured.

[0195] (Deformability evaluation)

[0196] The adhesive sheets obtained in the examples and comparative examples were cut into a size of 150 mm long × 50 mm wide, and laminated at room temperature (23°C) in a mirror-pasted manner with the adhesive layer of the adhesive sheet and the wafer substrate (mirror-finished silicone wafer, 6 inches, thickness 150 µm). The convex portion was observed through the substrate using a microscope, and the deformability was evaluated using the following criteria. It should be noted that if the convex portion is deformed, the concave portion that determines the boundary of the convex portion is also deformed according to the deformation, and the convex portion is not confirmed.

[0197] A: The number of unconfirmed convex portions accounts for 80% or more of the total convex portions.

[0198] B: The number of unconfirmed convex portions is 20% or more and less than 80% of the total convex portions.

[0199] F: The number of unconfirmed convex portions is less than 20 of the total convex portions.

[0200] (Resilience Assessment)

[0201] The adhesive layer of the adhesive sheet obtained in the example is adhered to a ring-shaped frame (made of stainless steel), and the adhesive sheet is cut according to the outer diameter of the ring-shaped frame. A wafer substrate (mirror-finished silicone wafer, 6 inches, 150µm thick) is fixed to a separately prepared dicing tape and cut into 10mm×10mm squares to make a plurality of components (silicon chips, the size of the components is 10mm×10mm×150µm). The plurality of components obtained are adhered to the central part of the inner side of the ring-shaped frame of the adhesive layer of the adhesive sheet, and the components are transferred from the dicing tape to the adhesive sheet by peeling off the dicing tape. At this time, the surface is adjusted in such a way that the mirror surface of the silicon chip is adhered to the adhesive layer of the adhesive sheet, and the pasting is performed by lamination at room temperature (23°C). Next, the adhesive sheet on which the components are placed and supported by the ring frame is placed on a surface having Fig. 8A and Figure 8B The expansion device of the mechanism shown in the figure presses down the annular frame at a speed of 1 mm / sec and a pull-down amount of 20 mm under the condition of a base support element for the adhesive sheet. After pressing down, the convex part of the adhesive sheet is observed through the substrate using a microscope, and the recovery is evaluated using the following criteria. It should be noted that if the convex part recovers, the boundary determined by the concave part can be confirmed, thereby confirming the convex part.

[0202] A: The number of unconfirmed convex portions accounts for 80% or more of the total convex portions.

[0203] B: The number of unconfirmed convex portions is 20% or more and less than 80% of the total convex portions.

[0204] F: The number of unconfirmed convex portions is less than 20 of the total convex portions.

[0205] The PSA sheets of Comparative Examples 1 and 2 were evaluated as F in the deformability evaluation, and since the convex portions were not deformed, the evaluation of the recoverability was not performed.

[0206] Table 1 shows the results of the complex shear elastic modulus, the deformability evaluation, and the recovery evaluation of Examples 1 to 6 and Comparative Examples 1 and 2.

[0207]

[0208] The adhesive sheets of Examples 1 to 6 have a complex shear elastic modulus of more than 0.001 MPa and less than 1.0 MPa at 23°C. In addition, the deformability of the convex portion of the adhesive sheets of Examples 1 to 4 was evaluated as A, the deformability of the convex portion of the adhesive sheets of Examples 5 and 6 was evaluated as B, and the resilience of the convex portion of the adhesive sheets of Examples 1 to 6 was evaluated as A. Therefore, the adhesive sheets of Examples 1 to 6 can change the retention of the element. That is, when the adhesive sheets of Examples 1 to 6 hold the element, the convex portion thereof will be deformed and flattened to firmly hold the element. In addition, the convex portion of the adhesive sheets of Examples 1 to 6 can weakly hold the element due to external stimulation and restoration to a convex shape, so that the element can be easily picked up from the adhesive sheet.

[0209] On the other hand, the adhesive sheets of Comparative Examples 1 and 2 have a complex shear elastic modulus of more than 1.0 MPa at 23°C. In addition, the deformability of the convex portion of the adhesive sheets of Comparative Examples 1 and 2 was evaluated as F. When the adhesive sheets of Comparative Examples 1 and 2 hold the element, the convex portion does not deform and cannot firmly hold the element. Therefore, the adhesive sheets of Comparative Examples 1 and 2 cannot change the holding property of the element.

[0210] As mentioned above, although embodiment of the invention was described, the invention is not limited to the above-mentioned embodiment, and various deformation|transformation and changes are possible within the scope of the gist of the invention.

[0211] This application claims the benefit of priority based on Japanese Patent Application No. 2022-151756 filed on September 22, 2022, Japanese Patent Application No. 2022-151757 filed on September 22, 2022, Japanese Patent Application No. 2023-058459 filed on March 31, 2023, Japanese Patent Application No. 2023-058460 filed on March 31, 2023, Japanese Patent Application No. 2023-058462 filed on March 31, 2023, and Japanese Patent Application No. 2023-058463 filed on March 31, 2023, and all the contents described therein are incorporated herein by reference.

Claims

1. An adhesive sheet comprising an adhesive layer for capturing an element separated from a holding substrate, The adhesive layer has irregularities on its surface and has a complex shear modulus of elasticity of 0.001 MPa to 1.0 MPa at 23°C.

2. The adhesive sheet according to claim 1, wherein The adhesive layer has a plurality of convex portions on its surface, the convex portions being bounded by concave portions and being separated from each other. The plurality of convex portions are deformed by being pressed when capturing the element, and the deformed plurality of convex portions are restored to a convex shape by an external stimulus.

3. The adhesive sheet according to claim 1, wherein The adhesive layer has a plurality of convex portions on its surface, the convex portions being bounded by concave portions and being separated from each other. The height of the plurality of protrusions is greater than 1 µm.

4. The adhesive sheet according to claim 1, wherein The adhesive layer is formed of an adhesive composition containing an energy ray-curable compound (B).

5. The adhesive sheet according to claim 1, wherein The adhesive layer is formed of an adhesive composition including an acrylic resin (A).

6. The adhesive sheet according to claim 1, wherein The adhesive layer is formed of an adhesive composition containing an acrylic resin (A) and an energy ray-curable compound (B).

7. The adhesive sheet according to claim 1, wherein The adhesive layer has a plurality of convex portions on its surface, the convex portions being bounded by concave portions and being separated from each other. The pitch of the plurality of protrusions is greater than or equal to 1µm and less than or equal to 100µm.

8. The adhesive sheet according to claim 1, wherein The adhesive layer has a plurality of convex portions on its surface, the convex portions being bounded by concave portions and being separated from each other. The area of ​​each of the plurality of protrusions is 10 μm 2 Above and 2000µm 2 the following.

9. The adhesive sheet according to claim 1, wherein The adhesive layer has a plurality of convex portions on its surface, the convex portions being bounded by concave portions and being separated from each other. A ratio of an area occupied by the convex portion to an area of ​​the adhesive layer is 1% or more and 95% or less.

10. The adhesive sheet according to claim 1, wherein The adhesive layer is configured such that a ratio of an area of ​​adhesion between the adhesive layer and one of the components to an area of ​​one of the components is 1% or more and 95% or less.

11. A method for manufacturing an electronic component or a semiconductor device, comprising the following steps: A step of separating a component adhered to a holding substrate from the holding substrate due to an external stimulus; A step of pressing the element separated from the holding substrate against the adhesive sheet according to claim 1 to deform a plurality of convex portions separated from each other and defined by concave portions on the surface of the adhesive layer, thereby holding the element on the adhesive layer; and The deformed plurality of convex portions are restored to a convex shape by an external stimulus, thereby accelerating the separation of the element from the adhesive sheet.

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