TW202223046A - Adhesive sheet for semiconductor processing and manufacturing method of semiconductor device wherein the adhesive sheet for semiconductor processing includes a substrate and an adhesive layer arranged on one surface of the substrate - Google Patents

Abstract

The present invention relates to an adhesive sheet for semiconductor processing and a method for manufacturing a semiconductor device using the adhesive sheet for semiconductor processing. The adhesive sheet for semiconductor processing includes a substrate and an adhesive layer arranged on one surface of the substrate. For the adhesive constituting the aforementioned adhesive layer, the breaking energy measured by the tensile test of method 1 is 7 MJ/m3 or more; for the aforementioned adhesive sheet, the variation of adhesion force measured by the peel test of method 2 before and after ultraviolet irradiation is from -10% to +10%.

Description

Adhesive sheet for semiconductor processing and manufacturing method of semiconductor device

The present invention relates to an adhesive sheet for semiconductor processing and a method for manufacturing a semiconductor device.

With the rapid progress in thinning, miniaturization, and multi-functionalization of information terminal devices, thinning and high-density semiconductor devices mounted on these devices are also required. As a method of reducing the thickness of a semiconductor device, there is a method of grinding the back surface of a semiconductor wafer used for the semiconductor device. The backside grinding of a semiconductor wafer is performed by attaching an adhesive sheet for backside grinding (hereinafter also referred to as a "backside grinding sheet") on the surface of the semiconductor wafer, with the sheet protecting the surface of the semiconductor wafer. The back grinding sheet is peeled and removed from the surface of the semiconductor wafer after back grinding.

An adhesive sheet for the purpose of protecting the surface of an object to be processed (hereinafter also referred to as a "workpiece") such as a back-grinding sheet is required to prevent accidental peeling from the workpiece in order to protect the surface of the workpiece well when processing the workpiece. force. On the other hand, when peeling from a workpiece, in order to prevent contamination of the workpiece, a peelability such that the adhesive does not remain on the workpiece is required.

In order to have both the adhesive force and the peelability of the adhesive sheet, there is a method of imparting energy ray curability to the adhesive layer. According to this method, when the workpiece is processed, the surface of the workpiece can be well protected by the adhesive layer with high adhesive force before energy ray hardening. On the other hand, when peeling from a workpiece, the adhesive layer is hardened by energy ray irradiation, and the peeling can be performed after reducing the adhesive force, so that the occurrence of sticking can be suppressed.

However, the method of using the energy ray-curable adhesive sheet requires an investment in equipment such as an energy ray irradiation device, which is economically disadvantageous. In addition, the work is also irradiated with energy rays for hardening the adhesive layer, which may cause damage to circuits and the like included in the work. Therefore, from the viewpoint of economy and productivity, an adhesive sheet for semiconductor processing which can be peeled off without residue without being irradiated with energy rays is desired.

Patent Document 1 discloses a re-peelable adhesive sheet having a base material and an adhesive layer laminated on the surface of the base material and used for back grinding of semiconductor wafers, the elastic modulus and heat shrinkage rate of the re-peelable adhesive sheet, and The thickness of the adhesive layer is within a specific range. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2011-91220

[The problem to be solved by the invention]

According to the technology of Patent Document 1, it is possible to provide re-peeling in which warpage, cracking, edge loss of the wafer, increase in adhesion to temperature changes, and/or contamination of the adherend during re-peeling are reduced and can be easily peeled off Sexually adhesive sheet. Therefore, convex parts such as bumps are sometimes provided on the surface of a workpiece such as a semiconductor wafer, and when processing the back surface of the surface having the convex parts, an adhesive sheet is attached to the surface having the convex parts. According to this method of use, in order to hold the workpiece well, the adhesive layer of the adhesive sheet is required to have sufficient embeddability of the protrusions. On the other hand, since the contact area between the workpiece and the adhesive layer is increased by embedding the convex portion, in addition to the large amount of deformation of the adhesive layer when the adhesive sheet is peeled off, in order to obtain sufficient convex portion for the adhesive layer Embedding requires flexibility, so sticking is more likely to occur during peeling than when it is attached to a smooth surface. Although the technique of patent document 1 has examined the peelability in the case of sticking to a smooth surface, it cannot fully respond to the request|requirement of suppressing the residue which arises from convex parts, such as a bump.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide an adhesive sheet for semiconductor processing which has sufficient embeddability of the convex portion, and which is not irradiated with energy rays to suppress sticking when peeling from a workpiece, and an adhesive sheet for semiconductor processing using the same. A method of manufacturing a semiconductor device with an adhesive sheet. [means to solve the problem]

As a result of active research, the present inventors found that the above-mentioned problems can be solved by adjusting the breaking energy of the adhesive constituting the adhesive layer and the rate of change in the adhesive force of the adhesive sheet before and after ultraviolet irradiation within a specific range, and thus accomplished the following: this invention.

That is, the present invention relates to the following [1] to [11]. [1] An adhesive sheet for semiconductor processing, comprising a substrate and an adhesive layer provided on one surface side of the substrate; an adhesive constituting the adhesive layer, which is subjected to the tensile test of the following method 1 The measured breaking energy is 7MJ/m ³ or more; For the above-mentioned adhesive sheet, the adhesive force change rate before and after ultraviolet irradiation measured by the peeling test of the following method 2 is -10~+10%; (Method 1) by A test piece having a shape of 0.20 mm in thickness, 15 mm in width, and 140 mm in length was prepared for the adhesive constituting the above-mentioned adhesive layer, and the test piece was used at 23° C., relative humidity of 50%, tensile speed of 200 mm/min, and distance between dots. The tensile test was carried out under the condition of 100mm, and the breaking energy was measured; (Method 2) The above-mentioned adhesive sheet with a width of 25mm was produced, so that the adhesive layer became the adhesive surface. Based on JIS Z0237:2000, the above-mentioned The adhesive sheet was attached to the mirror surface of the silicon mirror wafer, and then stored in an environment of 23°C and a relative humidity of 50% for 20 minutes as test piece A; for this test piece A, from the side of the adhesive sheet, the illumination was 220 mW/cm ^2. Irradiate ultraviolet rays under the condition of light intensity of 560mJ/cm ² , and then store it in an environment of 23°C and relative humidity of 50% for 5 minutes as test piece B; The peeling test of the aforementioned adhesive sheet was carried out under the conditions of humidity 50%, peeling angle 180°, and peeling speed 300 mm/min; And by the following formula (1), the adhesive force change rate before and after ultraviolet irradiation was calculated; [2] The adhesive sheet for semiconductor processing according to the above [1], wherein the thickness of the adhesive layer is 40 μm or more. [3] The adhesive sheet for semiconductor processing according to the above [1] or [2], wherein the adhesive force F1 of the adhesive sheet of the test piece A measured by the peel test of the aforementioned method 2 is 500 to 5,000 mN/25 mm. [4] The adhesive sheet for semiconductor processing according to any one of the above [1] to [3], wherein the adhesive layer is formed by an adhesive composition containing: a reactive functional The polymer (A) of the group (A1), the polymer (B) having a reactive functional group (B1) different from the aforementioned reactive functional group (A1) and a weight average molecular weight lower than that of the aforementioned polymer (A), The crosslinking agent (C) that reacts with the aforementioned reactive functional group (A1), and the crosslinking agent (D) that reacts with the aforementioned reactive functional group (B1) and is different from the aforementioned crosslinking agent (C). [5] The adhesive sheet for semiconductor processing according to the above [4], wherein both the polymer (A) and the polymer (B) are non-energy ray-curable polymers. [6] The adhesive sheet for semiconductor processing according to the above [4] or [5], wherein the weight average molecular weight of the polymer (A) is 400,000 to 1,000,000, and the weight average molecular weight of the polymer (B) is 120,000 to 350,000. [7] The adhesive sheet for semiconductor processing according to any one of the above [4] to [6], wherein the compounding amount of the polymer (B) is relative to 100 parts by mass of the compounding amount of the polymer (A) It is 10-80 mass parts. [8] The adhesive sheet for semiconductor processing according to any one of the above [4] to [7], wherein the functional group equivalent of the reactive functional group (B1) in the polymer (B) is 500 to 5,000 g/ mol. [9] The adhesive sheet for semiconductor processing according to any one of the above [4] to [8], wherein the reactive functional group (A1) is a carboxyl group, the reactive functional group (B1) is a hydroxyl group, and the crosslinking agent (C) is an epoxy-based crosslinking agent and the aforementioned crosslinking agent (D) is an isocyanate-based crosslinking agent; or the aforementioned reactive functional group (A1) is a hydroxyl group, the aforementioned reactive functional group (B1) is a carboxyl group, and the aforementioned crosslinking agent The linking agent (C) is an isocyanate-based crosslinking agent and the aforementioned crosslinking agent (D) is an epoxy-based crosslinking agent. [10] The adhesive sheet for semiconductor processing according to any one of the above [1] to [9], which is used as an adherend for a semiconductor device having a surface having one or more convex portions with a height of 10 μm or more and processing the semiconductor device in a state in which the adhesive layer is attached to the surface of the semiconductor device having one or more of the protrusions. [11] A method of manufacturing a semiconductor device, comprising the step of processing a semiconductor device having a surface having one or more convex portions having a height of 10 μm or more; The semiconductor device was processed in a state where the adhesive layer of the adhesive sheet for semiconductor processing according to any one of the above [1] to [10] was adhered to the surface of the semiconductor device. [Inventive effect]

According to the present invention, it is possible to provide an adhesive sheet for semiconductor processing which has sufficient embeddability of the convex portion and suppresses sticking when peeling from a workpiece without irradiating energy rays, and a method for manufacturing a semiconductor device using the same. .

In this specification, regarding the preferable numerical range, the lower limit value and the upper limit value are described in stages and can be combined independently, respectively. For example, based on the description of "preferably 10 to 90, more preferably 30 to 60", it is also possible to combine "preferable lower limit value (10)" and "preferable upper limit value (60)" to form "10" ~60".

In this specification, for example, "(meth)acrylic acid" means both "acrylic acid" and "methacrylic acid", and other similar terms are also the same.

In this specification, "energy rays" refer to those having energy quanta in electromagnetic waves or charged particle beams, and examples thereof include ultraviolet rays, radiation rays, electron beams, and the like. The ultraviolet rays can be irradiated using, for example, an electrodeless lamp, a high-pressure mercury lamp, a metal halide lamp, a UV-LED or the like as an ultraviolet source. The electron beam may be irradiated with an electron beam generated by an electron beam accelerator or the like. In this specification, "energy ray polymerizability" means the property of polymerizing by irradiation with energy ray. In addition, "energy ray sclerosis" means the property of hardening by irradiating energy ray, and "non-energy ray sclerosis" means the property of not having energy ray sclerosis.

In this specification, the "front surface" of a semiconductor wafer refers to the surface on which circuits are formed, and the "back surface" refers to the surface on which no circuits are formed.

In this specification, the solid content refers to all components other than the organic solvent, including those that are liquid in a standard state (23°C).

The mechanism of action described in this specification is presumed, and is not limited to the mechanism that exhibits the effects of the adhesive sheet for semiconductor processing of the present invention.

[Adhesive Sheet for Semiconductor Processing] The adhesive sheet for semiconductor processing (hereinafter also referred to as "adhesive sheet") of the present embodiment is an adhesive sheet for semiconductor processing including a base material and an adhesive layer provided on one surface side of the base material. The adhesive sheet of the present embodiment may or may not have layers other than the base material and the adhesive layer. As layers other than the base material and the adhesive layer, for example, an intermediate layer provided between the base material and the adhesive layer, a release material provided on the surface opposite to the substrate of the adhesive layer, and the like are exemplified.

<Fracture Energy of Adhesive> The adhesive layer included in the adhesive sheet of the present embodiment is composed of an adhesive whose fracture energy measured by the tensile test of the following method 1 is 7 MJ/m ³ or more. (Method 1) A test piece having a shape of 0.20 mm in thickness, 15 mm in width, and 140 mm in length was produced from the adhesive constituting the adhesive layer, and the test piece was used at 23° C., relative humidity of 50%, and tensile speed of 200 mm/min. The tensile test was carried out under the condition that the distance between the punctuation points was 100mm, and the breaking energy was measured. The tensile test of the above-mentioned method 1 is based on JIS K7127: 1999, and a more specific example is the method described in the following examples. In addition, the breaking energy is the integral value of the stress and strain up to the breaking point in the stress-strain curve obtained by the tensile test of the above-mentioned method 1.

When the breaking energy of the adhesive is 7 MJ/m ³ or more, it is difficult to cause cohesion failure in the adhesive layer, and even if it adheres to the surface having the convex portion, the sticking at the time of peeling is suppressed. From the same viewpoint, the breaking energy of the adhesive is preferably 8 MJ/m ³ or more, more preferably 9 MJ/m ³ or more, and still more preferably 10 MJ/m ³ or more. The upper limit value of the breaking energy of the adhesive is not particularly limited. From the viewpoint of maintaining a good balance with other properties, it is preferably 30MJ/m ³ or less, more preferably 25MJ/m ³ or less, and still more preferably 20MJ/m ³ . the following. The breaking energy of the adhesive can be adjusted by the polymer composition, monomer composition, etc. used to form the adhesive layer.

<Adhesion change rate> The adhesive sheet of this embodiment can be peeled off from the workpiece without being irradiated with energy rays, so the adhesion change rate before and after ultraviolet irradiation measured by the peeling test of the following method 2 is -10~+10 %. (Method 2) Make an adhesive sheet with a width of 25mm, so that the adhesive layer becomes the adhesive surface. Based on JIS Z0237:2000, use a 2kg rubber roller to attach the adhesive sheet to the mirror surface of the silicon mirror wafer. The test piece A was stored for 20 minutes at 23°C and relative humidity of 50%; the test piece A was irradiated with ultraviolet rays from the adhesive sheet side under the conditions of illuminance of 220 mW/cm ² and light intensity of 560 mJ/cm ² , and then irradiated with ultraviolet rays. Stored in an environment of 23°C and 50% relative humidity for 5 minutes is used as test piece B; using test piece A and test piece B, at 23°C, 50% relative humidity, peeling angle 180°, peeling speed 300mm/min The peeling test of the adhesive sheet was carried out under the condition of force change rate. Adhesion change rate before and after UV irradiation (%)=[(F2-F1)/F1]×100…(1). In addition, the example of the more specific aspect of the said method 2 is the method described in the Example mentioned later.

If the change rate of the adhesive force of the adhesive sheet is -10~+10%, even if the energy ray is accidentally or deliberately irradiated on the adhesive sheet during storage, transportation, use, etc., the change of the adhesive force can still be suppressed, so the quality of the adhesive sheet Excellent stability. Based on the same viewpoint, the adhesion change rate is preferably -7~+7%, more preferably -5~+5%, and still more preferably -3~+3%. The change rate of the adhesive force of the adhesive sheet can be adjusted by the polymer composition and monomer composition used to form the adhesive layer. Specifically, for example, by using a non-energy ray-curable polymer as the resin constituting the adhesive layer, the adhesive force change rate can be adjusted within the above-mentioned range.

Next, each member constituting the adhesive sheet of the present embodiment will be described in more detail.

＜Substrate＞ As a base material, a resin film is preferably exemplified from the viewpoint of being excellent in availability and reducing dust generation. Examples of the resin film include polyolefin-based films, vinyl halide polymer-based films, acrylic resin-based films, rubber-based films, cellulose-based films, polyester-based films, polycarbonate-based films, polystyrene-based films, Polyphenylene sulfide film, cycloolefin polymer film, etc. Among these, polyester-based films are preferred, and polyethylene terephthalate (hereinafter also referred to as "PET") films are more preferred from the viewpoint of being excellent in ease of acquisition and thickness accuracy, and capable of stably holding the workpiece. .

When a resin film is used as the base material, the base material may be a single-layer film made of one resin film, or a multi-layer film in which two or more resin films are laminated. And from the viewpoint of improving adhesion with other layers, the surface of the substrate may also have a coating. The thickness of the substrate is not particularly limited, but is preferably 10 to 200 μm, more preferably 20 to 100 μm, and still more preferably 30 to 70 μm. In addition, the thickness of the substrate can be measured by the method described in the examples.

<Adhesive layer> The adhesive layer is a layer provided on one surface side of the base material, and is a layer attached to the workpiece. Examples of the adhesive for forming the adhesive layer include acrylic adhesives, rubber-based adhesives, silicone-based adhesives, polyester-based adhesives, polyamide-based adhesives, urethane-based adhesives, Fluorine-based adhesives, styrene-diene block copolymer-based adhesives, etc. Among these, an acrylic adhesive is preferable.

The adhesive layer may be formed of an adhesive composition containing a polymer constituting the adhesive. The adhesive composition preferably contains a polymer (A) having a reactive functional group (A1), a reactive functional group (B1) having a different reactive functional group (A1) and a weight average molecular weight lower than the aforementioned Polymer (B) of polymer (A), cross-linking agent (C) reacted with reactive functional group (A1), and reactive with reactive functional group (B1) and different from cross-linking agent (C) Crosslinker (D). In addition, the adhesive composition containing a polymer (A), a polymer (B), a crosslinking agent (C), and a crosslinking agent (D) is called "adhesive composition (P)" below.

The polymer (A) contained in the adhesive composition (P) has a reactive functional group (A1), and the polymer (B) has a reactive functional group (B1) different from the reactive functional group (A1). Therefore, the polymer (A) is cross-linked by the cross-linking agent (C), and the polymer (B) is respectively cross-linked by the cross-linking agent (D). As a result, in the adhesive layer formed from the adhesive composition (P), a 3-dimensional mesh structure (hereinafter also referred to as "the first mesh"), and a so-called double network of a 3-dimensional mesh structure (hereinafter also referred to as "second mesh") formed of the polymer (B) and the crosslinking agent (D). Since this double network includes the intersection of the molecules constituting the first mesh and the molecules constituting the second mesh, flexibility is maintained and cohesion can be improved. Therefore, an adhesive having a double network formed has excellent followability to the shape of the convex portion of the workpiece, and has a good breaking energy, which tends to suppress sticking more effectively.

Each component of the adhesive composition (P) is explained in detail below.

(Polymer (A) and Polymer (B)) The polymer (A) and the polymer (B) are components that react with the cross-linking agent to form an adhesive. About each of the polymer (A) and the polymer (B), one type may be used alone, or two or more types may be used in combination.

[Weight Average Molecular Weight] The polymer (A) has a weight average molecular weight greater than that of the polymer (B). Thereby, the density of the cross-linked structure of the first mesh and the cross-linked structure of the second mesh can be set to be different, and there is a tendency to easily form a double network having the advantages obtained by both the cross-linked structures. From the same viewpoint, the difference between the weight average molecular weights of the polymer (A) and the polymer (B) is preferably 100,000 or more, more preferably 200,000 or more, and still more preferably 300,000 or more. In addition, the difference between the weight average molecular weights of the polymer (A) and the polymer (B) is preferably 800,000 or less from the viewpoint of easily adjusting the weight average molecular weights of the polymer (A) and the polymer (B) to each appropriate range. , more preferably 700,000 or less, still more preferably 500,000 or less. In addition, in this specification, the weight average molecular weight is a value in terms of standard polystyrene measured by gel permeation chromatography (GPC), and specifically is a value measured based on the method described in the examples.

The weight average molecular weight of the polymer (A) is not particularly limited, but is preferably 400,000-1,000,000, more preferably 450,000-800,000, still more preferably 500,000-700,000. When the weight average molecular weight of the polymer (A) is at least the above lower limit value, the first mesh tends to have a structure excellent in flexibility and stretchability, and the conformability to the shape of the convex portion of the workpiece tends to be further improved. And there exists a tendency for the coatability of an adhesive composition to become more favorable that the weight average molecular weight of a polymer (A) is below the said upper limit.

The weight average molecular weight of the polymer (B) is not particularly limited, but is preferably 120,000-350,000, more preferably 150,000-300,000, still more preferably 170,000-250,000. When the weight average molecular weight of the polymer (B) is below the above upper limit value, the second mesh tends to have a structure having a dense crosslink, and the cohesive force of the adhesive tends to be further improved. And when the weight average molecular weight of a polymer (B) is more than the said lower limit, it becomes easy to entangle with a 1st mesh, and there exists a tendency for sticking to be suppressed more effectively.

[Reactive functional group (A1) and reactive functional group (B1)] The reactive functional group (A1) and the reactive functional group (B1) are exemplified by, for example, a hydroxyl group, a carboxyl group, an amine group, an epoxy group, and the like. Among these, among the reactive functional group (A1) and the reactive functional group (B1), preferably one of them is a carboxyl group, and the other is a hydroxyl group, preferably the reactive functional group (A1) is a carboxyl group, and the reactive functional group is preferably a carboxyl group. The group (B1) is a hydroxyl group.

The functional group equivalent of the reactive functional group (A1) of the polymer (A) is not particularly limited, preferably 500 to 5,000 g/mol, more preferably 750 to 3,500 g/mol, and more preferably 1,000 to 2,000 g/mol mol. The functional group equivalent of the reactive functional group (B1) of the polymer (B) is not particularly limited, preferably 500-5,000 g/mol, more preferably 750-3,500 g/mol, and still more preferably 1,000-2,000 g/mol mol. When the functional group equivalents of the reactive functional group (A1) and the reactive functional group (B1) are at least the above lower limit, good reactivity with the crosslinking agent is obtained for both, and there is a tendency that a suitable double network can be formed. In addition, if the functional group equivalents of the reactive functional group (A1) and the reactive functional group (B1) are below the above-mentioned upper limit value, the unreacted reactive functional group in the adhesive can be reduced, and the quality stability tends to be improved. .

[polymer species] The polymer (A) and the polymer (B) are preferably both non-energy ray-curable polymers. If the polymer (A) and the polymer (B) are non-energy ray-curable polymers, it is easy to adjust the adhesive force change rate of the adhesive sheet within the above range. From the same viewpoint as above, it is preferable that the polymer (A) and the polymer (B) do not have a functional group having energy ray polymerizability. As the functional group having energy ray polymerizability, for example, an ethylenically unsaturated bond-containing functional group such as a (meth)acryloyl group, a vinyl group, and an allyl group is exemplified.

As a polymer (A) and a polymer (B), an acrylic polymer, a urethane polymer, a rubber-type polymer, a polyolefin etc. are mentioned, for example. Among these, an acrylic polymer and a urethane polymer are preferable, and an acrylic polymer is more preferable. The polymer (A) and the polymer (B) are preferably the same kind of polymer from the viewpoint of compatibility and the like. That is, when the polymer (A) is an acrylic polymer, preferably the polymer (B) is also an acrylic polymer. Moreover, when the polymer (A) is a urethane polymer, it is preferable that the polymer (B) is also a urethane polymer.

"Acrylic polymer used as polymer (A) and polymer (B)" The acrylic polymer used as a polymer (A) and a polymer (B) contains the structural unit derived from (meth)acrylate. The acrylic polymer (hereinafter also referred to as "acrylic polymer (Aa)") of the polymer (A) contains a structural unit derived from the functional group monomer (a1) having a reactive functional group (A1), and is more A copolymer containing a structural unit derived from an alkyl (meth)acrylate is preferable. This copolymer may copolymerize other monomers other than the above, or may copolymerize only the functional group monomer (a1) and alkyl (meth)acrylate. The acrylic polymer (hereinafter also referred to as "acrylic polymer (Ba)") of the polymer (B) contains a structural unit derived from the functional group monomer (b1) having a reactive functional group (B1), and furthermore Preferably, it is a copolymer containing the structural unit derived from the alkyl (meth)acrylate. This copolymer may copolymerize other monomers other than the above, or may copolymerize only the functional group monomer (b1) and alkyl (meth)acrylate. The acrylic polymer (Aa) and the acrylic polymer (Ba) may be a random copolymer or a block copolymer.

As a functional group monomer (a1) and a functional group monomer (b1), the monomer which has a hydroxyl group, a carboxyl group, an amine group, an epoxy group, etc. is mentioned. With respect to each of the functional group monomer (a1) and the functional group monomer (b1), one type may be used alone, or two or more types may be used in combination. Among these, preferably one of the functional group monomer (a1) and the functional group monomer (b1) is a monomer having a carboxyl group, and the other is a monomer having a hydroxyl group, preferably the functional group monomer (a1) ) is a monomer having a carboxyl group, and the functional group monomer (b1) is a monomer having a hydroxyl group.

Examples of the monomer having a carboxyl group include carboxylic acids having ethylenically unsaturated bonds such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is more preferable. Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. Hydroxyalkyl (meth)acrylate such as hydroxybutyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and the like. Among these, from the viewpoint of reactivity and copolymerizability with other monomers, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and (meth)acrylate is more preferred. ) 4-hydroxybutyl acrylate. In particular, when an acrylic polymer containing a structural unit derived from a hydroxyalkyl (meth)acrylate is crosslinked by an isocyanate-based crosslinking agent, it is more likely to preferentially react with the isocyanate-based crosslinking agent. The monomer is preferably 4-hydroxybutyl (meth)acrylate. The number of carbon atoms in the hydroxyalkyl group of the hydroxyalkyl (meth)acrylate is preferably 1 to 10 from the viewpoint of copolymerizability with other monomers and the reactivity with the above-mentioned isocyanate-based crosslinking agent, more preferably 1 to 10 carbon atoms. Preferably, it is 2 to 8, and more preferably, it is 3 to 6.

Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and (meth)acrylate. n-Amyl acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, n-ten (meth)acrylate Dialkyl ester, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, and the like. Among these, 2-ethylhexyl (meth)acrylate and n-butyl (meth)acrylate are preferred, and n-butyl (meth)acrylate is more preferred. Alkyl (meth)acrylate may be used individually by 1 type, and may use 2 or more types together. The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate is preferably 1 to 20, more preferably 2 to 10, and still more preferably 4 to 8, from the viewpoint of obtaining better adhesion.

Examples of other monomers include cycloalkyl (meth)acrylates having 3 to 20 carbon atoms in the cycloalkyl group, benzyl (meth)acrylates, isobornyl (meth)acrylates, and the like. (meth)acrylates with skeleton-like structures; vinyl ester compounds such as vinyl acetate and vinyl propionate; olefins such as ethylene, propylene, isobutylene, etc.; halogenated olefins such as vinyl chloride and vinylidene chloride; styrene, α- Styrene-based monomers such as methyl styrene; diene-based monomers such as butadiene, isoprene, chloroprene, etc.; nitrile-based monomers such as acrylonitrile, methacrylonitrile, etc. Other monomers may be used alone or in combination of two or more.

The content of the structural unit derived from the functional group monomer (a1) in the acrylic polymer (Aa) is not particularly limited, but is preferably 0.5 to 15% by mass relative to the total amount of the acrylic polymer (Aa), more preferably 1 ~10 mass %, more preferably 3 to 7 mass %. If the content of the structural unit derived from the functional group monomer (a1) is more than the above lower limit value, the reactivity of the acrylic polymer (Aa) and the crosslinking agent (C) will be good, and there is a possibility that a suitable first mesh is easily formed. tendency. In addition, when the content of the structural unit derived from the functional group monomer (a1) is below the above-mentioned upper limit value, the amount of unreacted reactive functional groups in the adhesive can be reduced, and the quality stability tends to be improved. The content of the constituent unit derived from alkyl (meth)acrylate in the acrylic polymer (Aa) is not particularly limited, but is preferably 85 to 99.5% by mass, more preferably 90% by mass relative to the total amount of the acrylic polymer (Aa). ~99 mass %, and more preferably 93 to 97 mass %. When content of the structural unit derived from alkyl (meth)acrylate is in the said range, there exists a tendency for more favorable adhesive force to be obtained. The content of the constituent units derived from other monomers in the acrylic polymer (Aa) is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the acrylic polymer (Aa), and More preferably, it is 1 mass % or less.

The content of the structural unit derived from the functional group monomer (b1) in the acrylic polymer (Ba) is not particularly limited, but is preferably 0.5 to 30 mass % relative to the total amount of the acrylic polymer (Ba), more preferably 1 ~20 mass %, more preferably 5 to 15 mass %. When the content of the structural unit derived from the functional group monomer (b1) is more than or equal to the above lower limit value, the reactivity of the acrylic polymer (Ba) and the crosslinking agent (D) is good, and there is a tendency that an appropriate second mesh is easily formed. . And when content of the structural unit derived from functional group monomer (b1) is below the said upper limit, the reactive functional group which does not react in an adhesive agent can be reduced, and there exists a tendency for quality stability to improve. The content of the constituent unit derived from the alkyl (meth)acrylate in the acrylic polymer (Ba) is not particularly limited, but is preferably 70 to 99.5% by mass, more preferably 75% by mass relative to the total amount of the acrylic polymer (Ba). ~99 mass %, more preferably 80 to 95 mass %. When content of the structural unit derived from alkyl (meth)acrylate is in the said range, there exists a tendency for more favorable adhesive force to be obtained. The content of structural units derived from other monomers in the acrylic polymer (Ba) is not particularly limited, but is preferably 10% by mass or less, more preferably 5% by mass or less, based on the total amount of the acrylic polymer (Ba), and More preferably, it is 1 mass % or less.

The acrylic polymer (Aa) and the acrylic polymer (Ba) can be produced, for example, by polymerizing the above-mentioned monomers by a radical polymerization method. A known method can be applied to the radical polymerization method. For example, a polymerization initiator can be used as necessary, and it can be carried out by a solution polymerization method or the like. As a polymerization initiator, an azo compound, an organic peroxide, etc. are mentioned, for example.

"Urethane polymer used as polymer (A) and polymer (B)" The urethane polymer used as the polymer (A) and the polymer (B) is a polymer containing at least one of a urethane bond and a urea bond. The urethane polymer used as the polymer (A) has the above-mentioned reactive functional group (A1), for example, a polyurethane having a carboxyl group. The urethane polymer used as the polymer (B) has the above-mentioned reactive functional group (B1), for example, a polyurethane having a hydroxyl group.

[Content of polymer (A) and polymer (B)] The content of the polymer (A) in the adhesive composition (P) is not particularly limited, and is based on the total solid content of the adhesive composition (P), preferably 40 to 95% by mass, more preferably 50 to 90 The mass % is more preferably 60 to 80 mass %. When the content of the polymer (A) is within the above-mentioned range, excellent flexibility, stretchability, and adhesive force derived from the first mesh can be obtained, and at the same time, by increasing the crossover frequency with the second mesh, it is more effective to suppress residue.

The content of the polymer (B) in the adhesive composition (P) is not particularly limited, but based on the total solid content of the adhesive composition (P), preferably 5 to 50% by mass, more preferably 10 to 10 40 mass %, more preferably 20 to 30 mass %. Moreover, the content of the polymer (B) in the adhesive composition (P) is not particularly limited, but relative to 100 parts by mass of the polymer (A), preferably 10 to 80 parts by mass, more preferably 20 to 60 parts by mass , and more preferably 30 to 50 parts by mass. When the content of the polymer (B) is within the above range, excellent cohesive force derived from the second mesh is obtained, and at the same time, by increasing the crossover frequency with the first mesh, sticking can be more effectively suppressed.

The total content of polymer (A) and polymer (B) in the adhesive composition (P) is not particularly limited, and is preferably 50 to 99.5 mass % based on the total solid content of the adhesive composition (P). , more preferably 80 to 99 mass %, still more preferably 90 to 98 mass %. When the total content of the polymer (A) and the polymer (B) is within the above range, the effect of improving the fracture properties by the double network can be sufficiently exhibited.

(Crosslinker (C) and Crosslinker (D)) The crosslinking agent (C) is a crosslinking agent for the polymer (A), and reacts with the reactive functional group (A1). And the crosslinking agent (D) is a crosslinking agent of the polymer (B), and reacts with the reactive functional group (B1). About each of the crosslinking agent (C) and the crosslinking agent (D), one type may be used alone, or two or more types may be used in combination.

The cross-linking agent (C) and the cross-linking agent (D) are of different types. The cross-linking agent (C) is appropriately selected according to the type of the reactive functional group (A1), and the cross-linking agent (D) is based on the reactive functional group. The type of the base (B1) is appropriately selected. Moreover, since the crosslinking agent (C) is a crosslinking agent of the polymer (A), it is a compound which reacts with the reactive functional group (A1) preferentially rather than the reactive functional group (B1). And since the crosslinking agent (D) is a crosslinking agent of the polymer (B), it is a compound which reacts with the reactive functional group (B1) preferentially rather than the reactive functional group (A1).

As the crosslinking agent (C) and the crosslinking agent (D), for example, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an amine-based crosslinking agent, a melamine-based crosslinking agent, and an azetidine-based crosslinking agent are exemplified. , hydrazine series crosslinking agent, aldehyde series crosslinking agent, oxazoline series crosslinking agent, metal alkoxide series crosslinking agent, metal chelate series crosslinking agent, metal salt series crosslinking agent, ammonium salt series crosslinking agent Joint agent, etc. Among these, when the reactive functional group (A1) is a carboxyl group, the crosslinking agent (C) is preferably an epoxy-based crosslinking agent or a metal chelate-based crosslinking agent, more preferably an epoxy-based crosslinking agent. Furthermore, when the reactive functional group (B1) is a hydroxyl group, the crosslinking agent (D) is preferably an isocyanate-based crosslinking agent. On the other hand, when the reactive functional group (A1) is a hydroxyl group, the crosslinking agent (C) is preferably an isocyanate-based crosslinking agent. Furthermore, when the reactive functional group (B1) is a carboxyl group, the crosslinking agent (D) is preferably an epoxy-based crosslinking agent or a metal chelate-based crosslinking agent, more preferably an epoxy-based crosslinking agent.

As the epoxy-based crosslinking agent, for example, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-meta -Xylene diamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidyl amine, etc. Among these, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane is preferred.

As the metal chelate type crosslinking agent, for example, acetylacetone, ethyl acetate, etc. are coordinated to polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium. Compounds such as ethyl acetoacetate, tris(2,4-glutarate), etc.

As an isocyanate type crosslinking agent, for example, a polyisocyanate compound is mentioned. Examples of the polyisocyanate compound include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; and isophorone diisocyanate. , cycloaliphatic polyisocyanates such as hydrogenated diphenylmethane diisocyanate; these urets, isocyanurates, adducts, etc. Among these, an adduct of a polyisocyanate compound is preferable. Examples of the adduct of the polyisocyanate compound include, for example, a reaction product of the above-mentioned polyisocyanate compound and a low molecular weight active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, and the like. Among these, polyol adducts of aromatic polyisocyanates such as toluene diisocyanate are preferable, and trimethylolpropane adducts of toluene diisocyanate are more preferable.

(Content of cross-linking agent (C) and cross-linking agent (D)) The content of the crosslinking agent (C) in the adhesive composition (P) is not particularly limited, but relative to 100 parts by mass of the polymer (A), it is preferably 0.005 to 0.5 parts by mass, more preferably 0.01 to 0.1 parts by mass, Still more preferably, it is 0.015-0.05 mass part. When content of a crosslinking agent (C) is more than the said lower limit, the 1st mesh which has moderate crosslinking can be formed, and there exists a tendency for sticking to be suppressed more effectively. Furthermore, when the content of the crosslinking agent (C) is below the above-mentioned upper limit value, the flexibility and stretchability of the first mesh are improved, and the followability to the shape of the convex portion possessed by the workpiece and the adhesive force tend to be improved.

The content of the crosslinking agent (D) in the adhesive composition (P) is not particularly limited, but relative to 100 parts by mass of the polymer (B), preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, Still more preferably, it is 3 to 10 parts by mass. When the content of the crosslinking agent (D) is more than the above lower limit value, the second mesh having a dense crosslinked structure can be formed, and there is a tendency for sticking to be suppressed more effectively. In addition, when the content of the crosslinking agent (D) is not more than the above-mentioned upper limit, the second mesh has moderate flexibility, and the followability to the shape of the convex portion possessed by the workpiece and the adhesive force tend to be improved.

The crosslinking of the crosslinking agent (C) and the crosslinking agent (D) is usually performed by heating the adhesive composition (P). That is, the adhesive composition (P), as will be described later, is heated in a state where a film is formed by coating or the like, and becomes a polymer (A) and a polymer (B) by a cross-linking agent (C) and a cross-linking agent. (D) Cross-linked adhesive layer.

(other ingredients) The adhesive composition may contain, as components other than the above, adhesion imparting agents, dyes, pigments, deterioration inhibitors, antistatic agents, flame retardants, silane coupling agents, chain Transfer agents, plasticizers, fillers, resin components other than the above-mentioned polymers, etc. However, the adhesive layer may not contain these components according to the desired properties. In particular, it is preferable not to contain a silane coupling agent from the viewpoint of reducing the residual paste. When a silane coupling agent is contained, it is based on the total solid content of an adhesive composition (P), Preferably it is 0.1 mass % or less, More preferably, it is 0.01 mass % or less, More preferably, it is 0.001 mass % or less.

The adhesive composition may contain an organic solvent from the viewpoint of facilitating coating when manufacturing an adhesive sheet. As the organic solvent, for example, methyl ethyl ketone, acetone, ethyl acetate, tetrahydrofuran, dioxane, cyclohexane, n-hexane, toluene, xylene, n-propanol, isopropanol and the like are exemplified. An organic solvent may be used individually by 1 type, and may use 2 or more types together.

(thickness of adhesive layer) The thickness of the adhesive layer can be appropriately adjusted according to the surface state of the surface to which the adhesive sheet is attached, such as the height of the convex portion of the workpiece. From the viewpoint of more effectively exhibiting the function of the adhesive sheet of this embodiment, it is preferably 10 μm or more, more preferably 10 μm or more. 30 μm or more, and more preferably 40 μm or more. In addition, the thickness of the adhesive layer is preferably 200 μm or less, more preferably 150 μm or less, and still more preferably 100 μm or less, from the viewpoint of practicality. In addition, the thickness of the adhesive layer can be measured by the method described in the Example.

(Adhesion of the adhesive sheet) The adhesive force F1 of the adhesive sheet of the test piece A measured by the peeling test of the above-mentioned method 2 of the adhesive sheet of the present embodiment is not particularly limited, but is preferably 500 to 5,000 mN/25 mm, more preferably 1,000 to 4,800 mN/ 25mm, and more preferably 1,500~4,600mN/25mm. When the adhesive force F1 is greater than or equal to the above lower limit value, there is a tendency that the protective performance of the adhesive sheet to the workpiece can be improved. In addition, when the adhesive force F1 is equal to or less than the above-mentioned upper limit value, even when it is attached to a workpiece having a convex portion such as a bump on the surface, sticking tends to be more effectively suppressed. The adhesive force of the adhesive layer can be adjusted by the type and compounding amount of the resin constituting the adhesive layer. For example, in the adhesive composition (P), by increasing the content of the cross-linking agent, the adhesive force tends to decrease, and by decreasing the content of the cross-linking agent, the adhesive force tends to increase.

＜Releasable material＞ As the release material, a release film in which a release agent is applied to a base material for release material is preferably exemplified. The release film may be a release film with a single-side release treatment, or a release film with a double-side release treatment. As the substrate for the release material, for example, a plastic film is preferably exemplified. As the plastic film, for example, polyester resin films such as polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, etc.; polypropylene resin, polyethylene resin, etc. The polyolefin resin film, etc. Examples of the release agent include rubber-based elastomers such as silicone-based resins, olefin-based resins, isoprene-based resins, butadiene-based resins, etc.; long-chain alkyl-based resins, alkyd-based resins, and fluorine-based resins Wait. The thickness of the peeling material is preferably 5 to 200 μm, more preferably 10 to 100 μm, and still more preferably 20 to 50 μm.

<Manufacturing method of adhesive sheet> The manufacturing method of the adhesive sheet of this embodiment is not particularly limited, and can be manufactured by a known method. For example, an adhesive sheet can be produced by a method such as directly applying the adhesive composition for forming the adhesive layer on a substrate, and then heating as necessary. Alternatively, an adhesive sheet can be produced by applying the adhesive composition to the peeling-treated surface of the release material to form an adhesive layer, and attaching the adhesive layer to a substrate. As a method of applying the adhesive composition, a conventional method can be used, for example, spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, gravure coating coating method, etc.

When the adhesive composition (P) is used as the adhesive composition, it is preferable to heat after coating. As a heating temperature, 80-110 degreeC is preferable, and 90-100 degreeC is more preferable. The heating time is preferably 1 to 5 minutes, more preferably 2 to 3 minutes. However, these heating conditions are preferably determined according to the kind of each component, etc., and are not limited to the above-mentioned range.

＜Use of adhesive sheet＞ The adhesive sheet of the present embodiment is attached to the surface of the semiconductor device of the workpiece, and is used for specific processing of the semiconductor device while protecting the surface. After specific processing, the adhesive sheet of this embodiment is peeled and removed from the semiconductor device. Also in this specification, the term "semiconductor device" refers to all devices that can function by utilizing the characteristics of semiconductors, such as semiconductor wafers, semiconductor chips, electronic parts including the semiconductor chips, and electronic machines equipped with the electronic parts. Wait. Among them, the adhesive sheet of this embodiment is suitable for processing of semiconductor wafers.

Examples of the processing performed in the state where the adhesive sheet of the present embodiment is attached are, for example, a back grinding process in which the adhesive sheet is attached to one side of the semiconductor device, and the other side is ground with the adhesive sheet attached to one side of the semiconductor device. Status: Dicing for singulation of semiconductor devices, transportation of semiconductor devices, pickup of semiconductor wafers, etc. Among these, the adhesive sheet of this embodiment is suitable for back grinding processing, and is more suitable for back grinding processing of grinding the back surface of a semiconductor wafer in a state where the adhesive sheet of this embodiment is attached to the circuit formation surface of the semiconductor wafer.

The adhesive sheet of the present embodiment is preferably used in a state where a semiconductor device having a surface having one or more convex portions is used as an adherend, and an adhesive layer is adhered to the surface having one or more convex portions of the semiconductor device. The above-described semiconductor device is processed. As described above, in the adherend having the convex portion, since the convex portion is in a state of being embedded in the adhesive layer of the adhesive sheet, sticking is likely to occur. On the other hand, since the adhesive sheet according to the present embodiment has good embeddability and can suppress sticking to a high degree, the adhesive sheet of the present embodiment can be more effectively exhibited by applying it to a surface having one or more convex portions function. The height of the protrusions is not particularly limited, but is preferably 10 μm or more, more preferably 12 μm or more, and still more preferably 14 μm or more, from the viewpoint of more effectively exhibiting the function of the adhesive sheet of the present embodiment. The height of the convex portion is not particularly limited, and may be, for example, 150 μm or less, 100 μm or less, or 50 μm or less. The distance between the protrusions is not particularly limited, but from the viewpoint of more effectively exhibiting the function of the adhesive sheet of the present embodiment, it is preferably 5 to 100 μm, more preferably 10 to 50 μm, and still more preferably 15 to 25 μm. Here, the "pitch" refers to the shortest distance among the distances between the centers of adjacent convex portions in plan view. The plan view shape of the convex portion is not particularly limited, and examples thereof include spherical, cylindrical, elliptical cylinder, spheroid, conical, elliptical cone, cube, rectangular parallelepiped, trapezoidal, and the like. As a semiconductor device provided with the surface which has one or more convex parts, the semiconductor wafer which has a bump as a convex part is exemplified, for example.

[Manufacturing method of semiconductor device] The method of manufacturing a semiconductor device according to the present embodiment is a method of manufacturing a semiconductor device including a step of processing a semiconductor device having a surface having one or more convex portions having a height of 10 μm or more. A method of manufacturing a semiconductor device in which the above-mentioned semiconductor device is processed in a state where the above-mentioned adhesive layer of the adhesive sheet for semiconductor processing of the present embodiment is attached to the surface of the above-mentioned convex portion.

The description of the semiconductor device having the surface having one or more convex portions and the description of the semiconductor device and the processing thereof are as described above. Among these, it is preferable that the process in the manufacturing method of the semiconductor device of this embodiment is the back grinding process which grinds the other surface in the state which adhered the adhesive sheet on one surface of the semiconductor device. A known method can be used for the back grinding process. Here, the adhesive sheet for semiconductor processing of the present embodiment can be peeled off from the workpiece without being irradiated with energy rays. Therefore, when peeling the adhesive sheet after processing, it is preferable not to irradiate the adhesive sheet with energy rays to peel off. However, "irradiation" here means intentionally irradiating the energy ray with the energy ray. [Example]

Hereinafter, the present invention is explained in more detail based on examples, but the present invention is not limited by these examples. The measurement methods and evaluation methods of various physical properties are as follows.

[Weight Average Molecular Weight (Mw)] The weight average molecular weight (Mw) was measured under the following conditions using a gel permeation chromatograph apparatus (manufactured by TOSOH Co., Ltd., product name "HLC-8220"), and was obtained by standard polystyrene conversion. (measurement conditions) • Columns: "TSK Guard Column HXL-H", "TSK Gel GMHXL (×2)" and "TSK Gel G2000HXL" (all manufactured by TOSOH Co., Ltd.) • Column temperature: 40℃ • Developing solvent: tetrahydrofuran • Flow rate: 1.0mL/min

[Thickness measurement of adhesive sheets, etc.] The total thickness of the adhesive sheet, the base material, the adhesive layer, and the thickness of the test piece produced therefrom were measured by a constant pressure thickness measuring device (manufactured by Teclock Co., Ltd., trade name "PG-02"). At this time, arbitrary 10 points were measured, and the average value was calculated. The total thickness of the adhesive sheet is the value obtained by measuring the thickness of the adhesive sheet with the release film and subtracting the thickness of the release film from the thickness. The thickness of the adhesive layer is the value obtained by subtracting the thickness of the substrate from the total thickness of the adhesive sheet.

[Measurement method of fracture energy] The breaking energy of the adhesive was measured in accordance with JIS K7127:1999 by performing the following tensile test. (1) Preparation of measurement samples By the same method as Example 1, 5 sheets of adhesive sheets with release films attached to both sides of the adhesive layer with a thickness of 40 μm were produced. Among them, the peeling film on one side is peeled off from the two adhesive sheets, and the exposed adhesive layers are laminated on each other. By repeating this procedure, 5 sheets of adhesive layers were laminated, and an adhesive sheet in which a release film was attached to both sides of the adhesive layer with a thickness of 0.20 mm was produced. The double-sided release film was peeled off from the adhesive sheet, and the adhesive layer was cut into pieces of 15 mm×140 mm, which were used as measurement samples for the tensile test.

(2) Tensile test Labels for film stretching were attached to 20 mm portions of both ends of the above-mentioned measurement sample, and a tensile tester (manufactured by Shimadzu Corporation, trade name "Autograph AG-IS 1kN") was used at 23°C and a relative humidity of 50%. , The tensile test is carried out under the conditions of a tensile speed of 200mm/min and a distance between the chucks of 100mm. A stress-strain curve was prepared from the obtained breaking stress and breaking elongation, and the breaking energy was obtained by calculating the area under the curve. In addition, the fracture energy is a value obtained by measuring three measurement samples for each level and averaging them.

[Evaluation of Embedding Property, Peelability and Residual Paste] (1) Preparation of wafer for evaluation As an adherend for peeling test, prepare a bump with a height of 15 μm, a pitch of 20 μm, and the dimensions of a length of 18 μm and a width of 18 μm in plan view. A wafer with 140 μm rectangular parallelepiped bumps (manufactured by Well Corporation, 8-inch wafer, bump specification Au=100% by mass, wafer surface material SiO ₂ ). Next, the release film was peeled off from the adhesive sheet produced in each example to prepare an adhesive sheet for exposing the adhesive layer. The adhesive sheet was placed on the wafer with the exposed adhesive layer facing the bump-forming surface of the wafer, and a laminator (manufactured by Lintec Co., Ltd., product name "RAD-3510F/12") was used. ) at room temperature (23° C.) to obtain a wafer for evaluation.

(2) Embedding evaluation The bump periphery of the wafer for evaluation was observed with a digital microscope (manufactured by Keyence Co., Ltd., product name "VHX-1000"), and the embedding property of the adhesive sheet was evaluated according to the following evaluation criteria. (Embedding Evaluation Criteria) A: The maximum width of the floating around the bump is 10 μm or less. B: The maximum width of the floating around the bump exceeds 10 μm.

(3) Peel test Using a wafer mounter (manufactured by LINTEC Co., Ltd., product name "RAD-2700F/12"), the adhesive sheet peeling test of the self-evaluation wafer was performed under the condition of a peeling speed of 4 mm/sec. In addition, in the peeling test, a test in which the temperature of the stage of the wafer mounter was set at room temperature (23° C.) and a test in which it was set at 40° C. were performed, respectively.

(4) Peelability evaluation Based on the results of the peeling test described above, the peelability of the adhesive sheet was evaluated according to the following evaluation criteria. (Evaluation criteria for peelability) A: The adhesive sheet was peeled off from the wafer, and no residue was visually observed on the wafer. B: Although the adhesive sheet was peeled off from the wafer, residue was observed on the wafer by visual observation. C: The adhesive sheet cannot be peeled off from the wafer.

(5) Residual paste evaluation Residue evaluation was performed by the following method about the said peelability evaluation of A or B. The bump portion of the wafer exposed by peeling the adhesive sheet was carried out using a digital microscope (manufactured by Keyence Co., Ltd., product name "VHX-1000") and a scanning electron microscope (manufactured by Keyence Co., Ltd., product name "VE-9800") ) was observed, and the residue was evaluated by the following evaluation criteria. Moreover, compared with a digital microscope, a scanning electron microscope can observe a finer residue. (Evaluation criteria for residual paste) A: Residual paste was not observed with both a digital microscope and a scanning electron microscope. B: Although no residue was observed with a digital microscope, some residue was observed with a scanning electron microscope. C: Residual paste was observed with both a digital microscope and a scanning electron microscope.

[Measurement of Adhesion Change Rate] The adhesive sheet obtained in each example was equally cut to a width of 25 mm, and the release film was peeled off and temporarily placed on the mirror surface of the silicon mirror wafer with the adhesive layer on the mirror surface side. On the temporarily placed adhesive sheet, based on JIS Z0237:2000, a rubber roller weighing 2kg reciprocates once, and a load is applied by the self-weight of the rubber roller, and the adhesive sheet is attached to the silicon mirror wafer. After attaching, it was stored in the environment of 23 degreeC and 50% of relative humidity for 20 minutes, and it was set as the test piece A. Next, with respect to the test piece A, a UV irradiation apparatus (manufactured by LINTEC Co., Ltd., trade name "RAD-2000m/12") was used under the conditions of an illuminance of 220 mW/cm ² , a light intensity of 560 mJ/cm ² , and an irradiation rate of 15 mm/sec. , and irradiate ultraviolet rays from the side of the adhesive sheet. Then, it preserve|saved for 5 minutes in the environment of 23 degreeC and 50% of relative humidity, and it was set as the test piece B. The test piece A and test piece B prepared above were used as the measurement objects, and were subjected to a tensile tester (manufactured by Dongfang Technology Co., Ltd., product name "Tensilon") at 23°C, relative humidity 50%, peeling angle 180°, Under the condition of peeling speed of 300 mm/min, the adhesive force when peeling off the adhesive sheet was measured. Let the adhesive force of the adhesive sheet of the test piece A be F1 and the adhesive force of the adhesive sheet of the test piece B to be F2, the adhesive force change rate before and after the ultraviolet irradiation was calculated by the following formula (1). Adhesion change rate before and after UV irradiation (%)=[(F2-F1)/F1]×100…(1).

[Manufacture of adhesive sheet] The adhesive sheet was produced by the method shown below. In addition, in each example, the description of "X/Y/Z=A/B/C" indicating the composition of the copolymer means that the copolymer is a copolymer of monomer X, monomer Y and monomer Z, so that A It is obtained by copolymerizing monomer X in parts by mass, monomer Y in parts by mass B, and monomer Z in parts by mass C. The abbreviations representing the monomers are as follows. BA: n-butyl acrylate AA: Acrylic 4HBA: 4-hydroxybutyl acrylate HEA: 2-hydroxyethyl acrylate MMA: methyl methacrylate

Example 1 (1) Preparation of substrate As a substrate, a PET film with a coating on both sides (manufactured by Toyobo Co., Ltd., trade name "COSOMO SHINE A4300", thickness: 50 μm, Young’s modulus at 23°C: 2,550MPa, breaking energy: 55.3MJ/m ³ ).

(2) Preparation of adhesive composition 100 parts by mass of the acrylic copolymer (composition: BA/AA=95/5, Mw: 600,000) as the polymer (A) and the acrylic copolymer (composition: BA/4HBA=90) as the polymer (B) /10, Mw: 200,000) 40 parts by mass, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane as a crosslinking agent (C) (manufactured by Mitsubishi Gas Chemical Co., Ltd., product name "TETRAD-C", 5% diluted product) 0.019 parts by mass, 4.90 parts by mass of an isocyanate-based cross-linking agent (manufactured by TOSOH Co., Ltd., product name "CORNATE L") as a cross-linking agent (D), as an organic The methyl ethyl ketone of the solvent was prepared so that the solid content concentration was 27 mass %, and the coating liquid of the adhesive composition was prepared by stirring for 30 minutes. In addition, the said compounding amount means the compounding amount of all solid content.

(3) Production of adhesive sheet The coating liquid of the adhesive composition obtained above was coated on the peeled surface of a PET-based release film (manufactured by LINTEC Co., Ltd., trade name "SP-PET381031", thickness 38 μm) with a knife coater, at 100 μm. The temperature was heated and dried for 2 minutes, and an adhesive layer with a thickness of 40 μm was formed on the release film. The adhesive layer is bonded to one surface of the previously shown substrate to form an adhesive sheet.

Embodiment 2~5, comparative example 1~4 An adhesive sheet was produced in the same manner as in Example 1, except that the composition of the adhesive composition was changed to the composition shown in Table 1.

Table 1 shows the results of each evaluation performed using the obtained adhesive sheet.

As can be seen from Table 1, the adhesive sheets of Examples 1 to 5 with a breaking energy of 7 MJ/m ³ or more have sufficient embedment properties, and the sticking is suppressed when peeling off the workpiece without irradiating energy rays. On the other hand, the adhesive sheets of Comparative Examples 1 to 4 with a breaking energy of less than 7 MJ/m ³ could not be peeled off under the peel test conditions, or even the suppression of peeling residue was insufficient.

Claims (11)

An adhesive sheet for semiconductor processing, comprising a substrate and an adhesive layer provided on one surface side of the substrate; an adhesive constituting the adhesive layer, which is measured by the tensile test of the following method 1 The breaking energy is 7MJ/m ³ or more; The aforementioned adhesive sheet has a rate of change of adhesive force before and after ultraviolet irradiation measured by the peel test of the following method 2 -10~+10%; (Method 1) The aforementioned adhesive is composed of A test piece with a thickness of 0.20 mm, a width of 15 mm, and a length of 140 mm was prepared as the adhesive of the agent layer, and the test piece was used under the conditions of 23°C, 50% relative humidity, 200 mm/min of tensile speed, and 100 mm of distance between punctuation points. (Method 2) Make the aforementioned adhesive sheet with a width of 25 mm, so that the adhesive layer becomes the adhesive surface. Based on JIS Z0237:2000, the aforementioned adhesive sheet is attached to a 2 kg rubber roller. Attached to the mirror surface of the silicon mirror wafer, and then stored in an environment of 23°C and a relative humidity of 50% for 20 minutes is used as test piece ^A ; Irradiate ultraviolet rays under the condition of 560mJ/ ^cm2 , and then store it for 5 minutes at 23℃ and 50% relative humidity as test piece B; The peeling test of the aforementioned adhesive sheet was carried out under the conditions of a peeling angle of 180° and a peeling speed of 300 mm/min. The following formula (1) calculates the adhesive force change rate before and after ultraviolet irradiation; Adhesion force change rate (%) before and after ultraviolet irradiation=[(F2-F1)/F1]×100…(1). The adhesive sheet for semiconductor processing according to claim 1, wherein the thickness of the adhesive layer is 40 μm or more. The adhesive sheet for semiconductor processing according to claim 1 or 2, wherein the adhesive force F1 of the adhesive sheet of the test piece A measured by the peel test of the aforementioned method 2 is 500 to 5,000 mN/25 mm. The adhesive sheet for semiconductor processing according to any one of Claims 1 to 3, wherein the adhesive layer is formed by an adhesive composition containing: a polymer having a reactive functional group (A1) Substance (A), a polymer (B) having a reactive functional group (B1) different from the aforementioned reactive functional group (A1) and a weight average molecular weight lower than the aforementioned polymer (A), and the aforementioned reactive functional group (A1) The reacted cross-linking agent (C) reacts with the aforementioned reactive functional group (B1) and is different from the aforementioned cross-linking agent (D) of the aforementioned cross-linking agent (C). The adhesive sheet for semiconductor processing according to claim 4, wherein the polymer (A) and the polymer (B) are both non-energy ray-curable polymers. The adhesive sheet for semiconductor processing according to claim 4 or 5, wherein the weight-average molecular weight of the polymer (A) is 400,000-1,000,000, and the weight-average molecular weight of the polymer (B) is 120,000-350,000. The adhesive sheet for semiconductor processing according to any one of claims 4 to 6, wherein the compounded amount of the polymer (B) is 10 to 80 parts by mass relative to the compounded amount of the aforementioned polymer (A) of 100 parts by mass . The adhesive sheet for semiconductor processing according to any one of claims 4 to 7, wherein the functional group equivalent of the reactive functional group (B1) in the polymer (B) is 500 to 5,000 g/mol. The adhesive sheet for semiconductor processing according to any one of claims 4 to 8, wherein the reactive functional group (A1) is a carboxyl group, the reactive functional group (B1) is a hydroxyl group, and the crosslinking agent (C) is an epoxy group is a cross-linking agent and the aforementioned cross-linking agent (D) is an isocyanate-based cross-linking agent; Alternatively, the reactive functional group (A1) is a hydroxyl group, the reactive functional group (B1) is a carboxyl group, the crosslinking agent (C) is an isocyanate-based crosslinking agent, and the crosslinking agent (D) is an epoxy-based crosslinking agent. agent. The adhesive sheet for semiconductor processing according to any one of Claims 1 to 9, which is used as follows: a semiconductor device having a surface having one or more convex portions having a height of 10 μm or more is used as an adherend, on the aforementioned semiconductor device. The said semiconductor device is processed in the state which stuck the said adhesive bond layer on the surface which has one or more said convex part. A method of manufacturing a semiconductor device, comprising the step of processing a semiconductor device having a surface having one or more convex portions having a height of 10 μm or more; The above-mentioned semiconductor device is subjected to a state in which the above-mentioned adhesive layer of the adhesive sheet for semiconductor processing according to any one of Claims 1 to 10 is attached to the surface of the above-mentioned semiconductor device having one or more of the above-mentioned convex portions. processing.