Adhesive film and method for manufacturing semiconductor device

Abstract

The invention relates to an adhesive film and a method for manufacturing a semiconductor device. The adhesive film is provided with an adhesive layer containing two or more types of polymers and a substrate layer, and satisfies (1) or (2). (1) The ratio (S ' / S) of the value (S') of the arithmetic mean height (Sa) of the surface of the adhesive layer when the adhesive film is stretched by 200% to the value (S ') of the arithmetic mean height (Sa) of the surface of the adhesive layer of the adhesive film before stretching is 9.5 or less, and (2) the difference between the SP values of at least two of the polymers is 0.3 or less, and the hydroxyl value ratio is 40 or less.

Description

Technical Field

[0001] The present invention relates to an adhesive film and a method for producing a semiconductor device. Background Art

[0002] In a method for manufacturing electronic components such as semiconductor chips and ceramic capacitors, the following steps are performed: after a wafer arranged on a stretchable film is singulated (cut) into desired sizes, the film is stretched to increase the distance between semiconductor chips, and the semiconductor chips are picked up (for example, refer to Patent Document 1).

[0003] In recent years, electronic component processing technology has become increasingly diverse, and research is underway on the technology of processing semiconductor chips that have been singulated on a stretched film. When processing semiconductor chips, it is required to increase the adhesive force of the stretched film so that the semiconductor chips will not fall off the stretched film or shift in position.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2023-63676 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, when the adhesiveness of the adhesive layer is increased in order to maintain the adhesive strength of the film during stretching, part of the adhesive layer moves to the adherend such as the chip, resulting in so-called adhesive residue on the adherend. As such, the adhesive strength during stretching and the suppression of adhesive residue on the adherend are in a trade-off relationship, and it is difficult to achieve both.

[0009] In view of the above circumstances, an object of one aspect of the present disclosure is to provide an adhesive film that can maintain adhesive strength even when stretched and can suppress adhesive residue on an adherend, and a method for manufacturing a semiconductor device using the adhesive film.

[0010] Means used to solve problems

[0011] Specific means for solving the above-mentioned problems include the following.

[0012] <1> An adhesive film comprising: an adhesive layer containing two or more polymers and a substrate layer,

[0013] A ratio S' / S of a value S' of an arithmetic mean height (Sa) of the surface of the adhesive layer when the adhesive film is stretched 200% to a value S of an arithmetic mean height (Sa) of the surface of the adhesive layer of the adhesive film before stretching is 9.5 or less.

[0014] <2> according to <1> The adhesive film described above, wherein the difference in SP values ​​between at least two of the two or more polymers is 0.3 or less.

[0015] <3> according to <1> The adhesive film described above, wherein the hydroxyl value ratio of at least two of the two or more polymers is 40 or less.

[0016] <4> An adhesive film comprising: an adhesive layer containing two or more polymers and a substrate layer,

[0017] The difference in SP value between at least two of the two or more polymers is 0.3 or less, and the hydroxyl value ratio is 40 or less.

[0018] <5> according to <1> ~ <4> The adhesive film according to any one of the preceding claims, wherein a value S of an arithmetic mean height (Sa) of the surface of the adhesive layer before extension is 0.001 μm to 5.000 μm.

[0019] <6> according to <1> ~ <5> The adhesive film as described in any one of the above-mentioned adhesive layers, wherein the content of the polymer with the largest content in the adhesive layer is 85% by mass or less relative to the total content of the two or more polymers contained in the adhesive layer.

[0020] <7> A method for manufacturing a semiconductor device, comprising: placing a plurality of semiconductor chips on one surface of a <1> ~ <6> The adhesive film described above is stretched to increase the distance between the two adjacent semiconductor chips.

[0021] <8> according to <7> The method for manufacturing a semiconductor device includes: after the stretching, peeling the semiconductor chip from the adhesive film.

[0022] <9> according to <8> The method for manufacturing a semiconductor device comprises: processing the semiconductor chip after the stretching and before the peeling of the semiconductor chip.

[0023] <10> according to <9> The method for manufacturing a semiconductor device, wherein the processing includes providing a functional layer on the semiconductor chip.

[0024] Effects of the Invention

[0025] According to one aspect of the present disclosure, it is possible to provide an adhesive film that can maintain adhesive strength even when stretched and can suppress adhesive residue on an adherend, and a method for manufacturing a semiconductor device using the adhesive film. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic cross-sectional view showing the structure of an adhesive film.

[0027] Description of Reference Numerals

[0028] 10. Base material layer

[0029] 20 Adhesive layer

[0030] 30 Adhesive film DETAILED DESCRIPTION

[0031] The following is a detailed description of the methods for implementing the present disclosure. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not required unless otherwise specified. The same is true for numerical values ​​and their ranges, which do not limit the present disclosure.

[0032] In the present disclosure, the term "process" includes not only a process that exists independently of other processes, but also a process that cannot be clearly distinguished from other processes as long as the purpose of the process can be achieved.

[0033] In the present disclosure, a numerical range expressed using "to" includes the numerical values ​​described before and after "to" as a minimum value and a maximum value, respectively.

[0034] In the numerical ranges recorded in the present disclosure, the upper limit or lower limit recorded in one numerical range can be replaced by the upper limit or lower limit of the numerical range recorded in other steps. In addition, in the numerical ranges recorded in the present disclosure, the upper limit or lower limit of its numerical range can be replaced by the value shown in the embodiment.

[0035] In the present disclosure, each component may include a plurality of corresponding substances. When a plurality of substances belonging to each component are present in the composition, the content rate or content of each component refers to the total content rate or content of the plurality of substances present in the composition unless otherwise specified.

[0036] In the present disclosure, the term "layer" includes not only a case where the layer is formed on the entire region when the region where the layer exists is observed, but also a case where the layer is formed on only a part of the region.

[0037] In the present disclosure, the thickness of the adhesive film or each layer constituting the adhesive film can be measured by a known method. For example, it can be measured using a micrometer or the like, or it can be measured from a cross-sectional image of the adhesive film. Alternatively, the material constituting the layer can be removed using a solvent or the like, and the thickness can be calculated from the mass before and after removal, the density of the material, the area of ​​the layer, etc. In the case where the thickness of the layer is not fixed, the arithmetic mean of the values ​​measured at 5 random locations is taken as the thickness of the layer.

[0038] In the present disclosure, “(meth)acrylic acid” refers to either or both of acrylic acid and methacrylic acid, and “(meth)acrylate” refers to either or both of acrylate and methacrylate.

[0039] In the present disclosure, when the embodiments are described with reference to the drawings, the configuration of the embodiments is not limited to the configuration shown in the drawings. In addition, the sizes of the components in each figure are conceptual sizes, and the relative relationship between the sizes of the components is not limited to this.

[0040] <Adhesive film>

[0041] An adhesive film according to one embodiment of the present disclosure includes an adhesive layer containing two or more polymers and a substrate layer, and satisfies the following (1) or (2).

[0042] (1) The ratio S' / S of the arithmetic mean height (Sa) of the adhesive layer when the adhesive film is stretched 200% to the arithmetic mean height (Sa) of the adhesive layer before stretching is 9.5 or less.

[0043] (2) The difference in SP value between at least two of the above polymers is 0.3 or less, and the hydroxyl value ratio is 40 or less.

[0044] The adhesive film of the present disclosure having the above-mentioned structure can maintain adhesive strength even when stretched, and can suppress residual adhesive on the adherend.

[0045] When the adhesive layer contains only one polymer, for example, when a polymer with improved adhesion is used, the adhesive force can be improved, and when a polymer with improved peelability is used, the residual adhesive on the adherend when the adherend is peeled off can be suppressed. However, it is difficult for an adhesive layer containing only one polymer to achieve both.

[0046] The adhesive film disclosed in the present invention contains two or more polymers in the adhesive layer, and is intended to improve the adhesive strength and suppress the residual adhesive when the adherend is peeled off. In particular, by making the ratio S' / S of the arithmetic mean height (Sa) value S' of the surface of the adhesive layer when the adhesive film is stretched by 200% to the arithmetic mean height (Sa) value S of the surface of the adhesive layer of the adhesive film before stretching 9.5 or less, the surface unevenness of the adhesive film during stretching can be appropriately suppressed, and the adhesive strength can be effectively maintained when the adhesive film is stretched.

[0047] In addition, by making the adhesive layer contain at least two polymers having a difference in SP value of 0.3 or less, the generation of a microphase separation structure of the polymer in the adhesive layer can be appropriately suppressed. Thus, when the adhesive film is stretched, the generation of unevenness on the surface of the adhesive film caused by the microphase separation structure can be appropriately suppressed, and the adhesive force can be maintained even during stretching.

[0048] Furthermore, by making the adhesive layer contain at least two polymers having a hydroxyl value ratio of 40 or less, these polymers are appropriately compatible, so the generation of a microphase separation structure can be appropriately suppressed. When the hydroxyl value ratio is 40 or less, it is possible to suppress the aggregation of polymers with large hydroxyl values ​​and polymers with small hydroxyl values, respectively, and the generation of a microphase separation structure can be appropriately suppressed.

[0049] As an example of the adhesive film disclosed in the present invention, Figure 1 The cross-sectional structure of the adhesive film is schematically shown in FIG. Figure 1 As shown, the adhesive film 30 includes a substrate layer 10 and an adhesive layer 20. The adhesive film 30 may also have other layers.

[0050] [Adhesive layer]

[0051] The adhesive layer contains two or more polymers. Preferred examples include: a difference in SP value between at least two polymers of 0.3 or less, and a hydroxyl value ratio of 40 or less.

[0052] When the difference in SP value of at least two polymers is below 0.3, these polymers have high compatibility with each other, so there is a tendency that it is difficult to form a phase separation structure in the adhesive layer. When the adhesive layer with many or large phase separation structures is stretched, the elongation of the adhesive layer becomes locally uneven, and it is easy to have unevenness on the surface of the adhesive layer.

[0053] The difference in SP value between at least two polymers contained in the adhesive layer is preferably 0.2 or less, and more preferably 0.1 or less. The lower limit of the difference in SP value is not particularly limited. In the present disclosure, the SP value is a value obtained by the Fedors method.

[0054] Furthermore, when the hydroxyl value ratio of at least two polymers is 40 or less, aggregation of the polymers is suppressed, and a phase separation structure tends to be less likely to be formed in the adhesive layer.

[0055] The hydroxyl value ratio of at least two types of polymers contained in the adhesive layer is preferably 30 or less, more preferably 15 or less.

[0056] Furthermore, the hydroxyl value ratio of at least two polymers contained in the adhesive layer is preferably 1.5 or more, more preferably 2.0 or more, and even more preferably 3.0 or more.

[0057] A polymer with a large hydroxyl value is easy to become hard when undergoing a cross-linking reaction, while a polymer with a small hydroxyl value is a polymer that is not easy to harden even after undergoing a cross-linking reaction. From the viewpoint of the excellent adhesiveness of the adhesive film, it is ideal that the adhesive film is soft, but as a contradictory characteristic, there is a tendency for residual adhesive to occur easily due to cohesive failure during peeling. When the hydroxyl value ratio of at least two polymers contained in the adhesive layer is 1.5 or more, a hard polymer can be intercalated between the soft polymers, and residual adhesive caused by cohesive failure can be effectively suppressed.

[0058] In addition, the hydroxyl value ratio in this disclosure is calculated using the hydroxyl value of the polymer with a smaller hydroxyl value among two polymers as the denominator and the hydroxyl value of the polymer with a larger hydroxyl value as the numerator.

[0059] The hydroxyl value is the number of mg of potassium hydroxide required to neutralize acetic acid bonded to the hydroxyl group when 1 g of a sample is acetylated, and is determined from a calculated value of the following formula.

[0060]

[0061] The type of polymer is not particularly limited, and is preferably selected in consideration of the adhesiveness and heat resistance of the adhesive layer. Specifically, the polymer may include (meth)acrylic polymers, silicones, urethane polymers, etc. Preferably, at least one of the polymers is a (meth)acrylic polymer, and more preferably, two or more (meth)acrylic polymers are used.

[0062] The (meth)acrylic polymer may be a homopolymer or a copolymer, or a homopolymer and a copolymer may be used in combination. It is preferred that at least one of the (meth)acrylic polymers is a copolymer.

[0063] The copolymer preferably contains structural units derived from monomers having a relatively low glass transition temperature (Tg) (e.g., below 20°C). It should be noted that a monomer having a relatively low Tg refers to a monomer having a glass transition temperature of 20°C or less when synthesizing a homopolymer with the monomer. As monomer A having a Tg of 20°C or less, butyl (meth)acrylate, ethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, etc. can be cited. The copolymer may contain one structural unit derived from monomer A alone or in combination of two or more.

[0064] When the copolymer includes a structural unit derived from monomer A, the total content of the structural units derived from monomer A in the copolymer is preferably more than 60% by mass, more preferably 70% by mass or more, and further preferably 75% by mass or more. In addition, the total content is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 88.5% by mass or less.

[0065] At least one polymer can be a copolymer comprising a structural unit derived from a monomer B having a functional group. As the functional group, carboxylic acid group, hydroxyl group, amide group, nitrile group, etc. can be listed. The functional group can be a crosslinking functional group or a non-crosslinking functional group. As the crosslinking functional group, carboxylic acid group, hydroxyl group, amide group, etc. can be listed, and as the non-crosslinking functional group, nitrile group, etc. can be listed. The copolymer can include a single structural unit derived from monomer B, or it can include it in a combination of two or more.

[0066] The copolymer containing the structural unit derived from the monomer B having a functional group may also be a cross-linked polymer. The cross-linked polymer may be cross-linked using a cross-linking agent. The cross-linked polymer is preferably a cross-linked (meth)acrylic polymer, and more preferably a cross-linked (meth)acrylic copolymer.

[0067] Examples of the monomer B1 having a crosslinkable functional group include (meth)acrylic acid, hydroxyethyl (meth)acrylate, and (meth)acrylamide.

[0068] Examples of the monomer B2 having a non-crosslinkable functional group include (meth)acrylonitrile and the like.

[0069] When the copolymer contains a structural unit derived from monomer B1, the total content of the structural unit derived from monomer B1 in the copolymer is preferably 0.5% by mass or more, more preferably 4.0% by mass or more, and further preferably 10% by mass or more. In addition, the total content is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less.

[0070] When the copolymer includes the structural unit derived from the monomer B2, the total content of the structural unit derived from the monomer B2 in the copolymer is preferably 1% by mass or more, more preferably 3% by mass or more, and further preferably 5% by mass or more. In addition, the content is preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less.

[0071] The copolymer may also contain structural units derived from other monomers other than the monomer A and the monomer B. Examples of the other monomers include monomers having a Tg of more than 20° C., such as 1-adamantyl acrylate and 1-adamantyl methacrylate. The total content of structural units derived from other monomers in the copolymer is preferably 20% by mass or less, more preferably 10% by mass or less.

[0072] From the viewpoint of suppressing residual adhesive on the adherend, the weight average molecular weight (Mw) of the polymer may be, for example, 1×10 5 Above, it can also be 3×10 5 In addition, from the viewpoint of ensuring adhesion, Mw may be 1×10 6 the following.

[0073] From the viewpoint of suppressing residual adhesive on the adherend, the number average molecular weight (Mn) of the polymer can be 10×10 4 Above, it can also be 12×10 4 In addition, from the viewpoint of ensuring adhesion, Mn may be 20×10 4 Below, it can also be 15×10 4 the following.

[0074] Mn and Mw of a polymer are measured by a conventional method using GPC (gel permeation chromatography).

[0075] The content of the polymer with the highest content in the adhesive layer is preferably 85% by mass or less relative to the total content of the polymer contained in the adhesive layer, more preferably 83% by mass or less, and further preferably 78% by mass or less. When the content of the polymer with the highest content is 85% by mass or less, there is a tendency to further suppress the generation of residual adhesive when the semiconductor chip is peeled off.

[0076] When the polymer includes a crosslinked polymer, the adhesive layer preferably contains a crosslinking agent. In the present disclosure, a state in which a part or all of the crosslinking agent contained in the adhesive layer forms a crosslinked structure is also referred to as "a state in which the adhesive layer contains a crosslinking agent."

[0077] There is no particular limitation on the type of crosslinking agent, and the crosslinking agent can be selected according to the type of polymer of the adhesive layer, etc. Specifically, isocyanate crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, amine crosslinking agents, etc. can be cited.

[0078] Among the above cross-linking agents, isocyanate cross-linking agents are preferred from the viewpoint of stable adhesive properties. The cross-linking agent contained in the adhesive layer may be a single type or a combination of two or more types.

[0079] The isocyanate crosslinking agent is not particularly limited and can be selected from known compounds having isocyanate groups (isocyanate compounds). From the viewpoint of reactivity, bifunctional isocyanate compounds (compounds having two isocyanate groups) and polyfunctional isocyanate compounds (compounds having three or more isocyanate groups) are preferred, and polyfunctional isocyanate compounds are more preferred.

[0080] Examples of the bifunctional isocyanate compound include aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, carbodiimide-modified products of these diisocyanate compounds, and polymer compounds having these diisocyanate compounds in their molecules.

[0081] Examples of the aliphatic diisocyanate compound include 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), and lysine diisocyanate.

[0082] Examples of the alicyclic diisocyanate compound include norbornane diisocyanatomethyl ester (NBDI), trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI), and H12-MDI (hydrogenated MDI).

[0083] Examples of the aromatic diisocyanate compound include dimer acid diisocyanate, 2,4-toluene diisocyanate (2,4-TDI), 2,6-toluene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), and 1,5-naphthalene diisocyanate (NDI).

[0084] Examples of the polyfunctional isocyanate compound include a trimer of a bifunctional isocyanate compound and a polymer compound having a trimer of a bifunctional isocyanate compound in a molecule.

[0085] Examples of the trimer of a bifunctional isocyanate compound include an isocyanurate form of a bifunctional isocyanate compound, an adduct of a bifunctional isocyanate compound, and a biuret form of a bifunctional isocyanate compound.

[0086] Among the isocyanate crosslinking agents, trimers of aliphatic diisocyanate compounds are preferred, adducts of aliphatic diisocyanate compounds are more preferred, adducts of 1,6-hexamethylene diisocyanate are further preferred, and trimethylolpropane (TMP) adducts of 1,6-hexamethylene diisocyanate are particularly preferred.

[0087] The content of the crosslinking agent in the adhesive layer may be, for example, 0.1 to 10 parts by mass, 0.5 to 5 parts by mass, or 1 to 3 parts by mass based on 100 parts by mass of the total amount of the polymer contained in the adhesive layer.

[0088] As required, the adhesive layer may include a plasticizer. The type of plasticizer is not particularly limited and can be selected according to the type of polymer of the adhesive layer. Specifically, polyester plasticizers such as adipic acid polyester, phthalic acid esters such as bis(2-ethylhexyl) phthalate, terephthalic acid esters such as bis(2-ethylhexyl) terephthalate, adipic acid esters such as bis(2-ethylhexyl) terephthalate, trimellitic acid esters, phosphates, citrates, epoxidized vegetable oils, etc. can be listed.

[0089] The plasticizer contained in the adhesive layer may be a single type or a combination of two or more types.

[0090] The molecular weight of the polyester plasticizer is not particularly limited, and may be, for example, in the range of 500 to 4,000.

[0091] From the viewpoint of suppressing residual adhesive on an adherend, the molecular weight of the polyester plasticizer is preferably 1,500 to 4,000.

[0092] The content of the plasticizer in the adhesive layer may be, for example, 5 to 30 parts by mass, 10 to 25 parts by mass, or 15 to 22 parts by mass based on 100 parts by mass of the total amount of the polymer contained in the adhesive layer.

[0093] The adhesive layer may also contain a tackifier as required. The type of tackifier is not particularly limited and may be selected according to the type of polymer of the adhesive layer. Specifically, petroleum resins, terpene phenol resins, terpene resins, alicyclic saturated hydrogen resins, β-terpene polymers, hydrogenated rosin, and hydrogenated rosin esters may be cited.

[0094] When the adhesive layer contains a tackifier, the adhesive strength before elongation tends to be improved, and the adhesive retention property tends to be more excellent.

[0095] As required, the adhesive layer may also include a surfactant, a filler, etc. The content of the filler in the adhesive layer is preferably 30% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass or less relative to the solid content contained in the adhesive layer from the viewpoint of suppressing the reduction of the adhesive force before elongation. The lower limit when the adhesive layer contains a filler is not particularly limited, for example, it can be 1% by mass or more, or it can be 5% by mass or more.

[0096] The thickness of the adhesive layer is preferably 1 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more from the viewpoint of ensuring sufficient adhesive force to the adherend. From the viewpoint of economic efficiency, the thickness of the adhesive layer is preferably 100 μm or less, more preferably 50 μm or less, and further preferably 30 μm or less.

[0097] The concave and convex portions of the surface concavities and convexities formed by stretching the adhesive film preferably have different polymer component ratios. As an example, the nitrile group content is preferably different in the concave and convex portions, and more preferably the nitrile group content is higher in the convex portions than in the concave portions.

[0098] The composition ratio of the polymer in each region and the concavo-convex portion is determined by analyzing the distribution of the components constituting the surface of the adhesive layer using micro-Raman spectroscopy. For example, for the multiple components constituting the adhesive layer, the peaks derived from the components to be analyzed are identified in advance, and the distribution amount of the components is imaged in two dimensions based on the signal intensity, thereby analyzing the distribution of each component.

[0099] The adhesive film of the present disclosure may have convex portions where no clear interface can be confirmed. The convex portions where no clear interface can be confirmed mean that when observed with a laser microscope, the particle interface cannot be confirmed as when a filler is added.

[0100] [Base material layer]

[0101] The substrate layer is not particularly limited and can be appropriately selected from substrate layers used in the art. From the viewpoint of obtaining good elongation, the substrate layer preferably contains a resin, and more preferably contains a thermoplastic resin.

[0102] Examples of the thermoplastic resin include polyvinyl chloride, polyester, polyolefin, polyamide, polyimide, polyurethane, and thermoplastic elastomer. From the viewpoint of elongation, polyvinyl chloride is preferred.

[0103] The substrate layer may also contain a plasticizer. When the substrate layer contains a plasticizer, the content of the plasticizer contained in the substrate layer may be, for example, 10 to 55 parts by mass, 20 to 50 parts by mass, or 25 to 45 parts by mass relative to 100 parts by mass of the resin contained in the adhesive layer.

[0104] From the viewpoint of improving visibility during attachment, the base material layer may contain a colorant.

[0105] Examples of the colorant include dyes and pigments, and pigments are preferred from the viewpoint of durability. Specific examples of the colorant include basic blue, disazo yellow, phthalocyanine blue, Prussian blue, ultramarine, and cobalt blue.

[0106] When the colorant is in a granular form, the maximum particle size of the colorant is preferably smaller than the thickness of the substrate layer when stretched from the viewpoint of suppressing the colorant from falling off from the substrate layer. For example, the maximum particle size of the colorant is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 10 μm or less.

[0107] In the present disclosure, the “maximum particle size” of the colorant is defined as the maximum value of the maximum diameter of each particle obtained from the projected image of particles (preferably 100 or more) of the colorant (the length of the projected image when the diameter is the longest).

[0108] When the base layer contains a colorant, the content of the colorant in the base layer is, for example, preferably 0.1 to 2.0 mass %, more preferably 0.2 to 1.5 mass %, and further preferably 0.3 to 1.0 mass % relative to the total solid content of the base layer.

[0109] The thickness of the base material layer is preferably 10 μm or more, more preferably 20 μm or more, and further preferably 50 μm or more, from the viewpoint of ensuring sufficient strength.

[0110] From the viewpoint of ensuring sufficient elongation, the thickness of the substrate layer is preferably 500 μm or less, more preferably 200 μm or less, and further preferably 150 μm or less.

[0111] [Other components]

[0112] If necessary, a separator or the like may be disposed on the outer surface of the adhesive layer (the surface on the opposite side to the side facing the base material layer).

[0113] <Physical Properties of Adhesive Film>

[0114] In one embodiment of the adhesive film disclosed herein, a ratio S' / S of arithmetic mean height (Sa) of the adhesive layer surface when the adhesive film is stretched 200% to arithmetic mean height (Sa) of the adhesive layer surface of the adhesive film before stretching is 9.5 or less.

[0115] In the present disclosure, the elongation of the adhesive film to 200% is performed by the following method.

[0116] Before the adhesive film is stretched, two points are marked on the surface of the adhesive layer, and the film is stretched until the distance between the two points is doubled. During the stretching, the two points are clamped with clamps, and the clamps are moved in opposite directions to stretch the adhesive film. The distance between the two points can be set to 10 mm, for example.

[0117] In the present disclosure, the value S of the arithmetic mean height (Sa) is measured by the following method.

[0118] The adhesive film was placed on a laser microscope with the adhesive layer side facing upward, and image processing was performed at a magnification of 100 times to obtain the arithmetic mean height (Sa) of the adhesive layer surface as a value S.

[0119] In the present disclosure, the value S' of the arithmetic mean height (Sa) is measured by the following method.

[0120] The adhesive film was stretched 200% by the above method and then attached to a frame plate with a side length of 50 mm. The frame plate was placed under a laser microscope and imaged at a magnification of 100 times to obtain the arithmetic mean height Sa of the adhesive layer surface as the value S'.

[0121] As a laser microscope used for measuring the value S and the value S′, for example, “Laser Microscope OLS4100” manufactured by Olympus Corporation can be used.

[0122] The ratio S' / S is preferably 8 or less, and more preferably 5 or less. The lower limit of the ratio S' / S is not particularly limited, and may be 0.5 or more, or 1.0 or more.

[0123] From the viewpoint of adhesive strength, the value S of the arithmetic mean height (Sa) is preferably 4.000 μm or less, more preferably 2.000 μm or less, and further preferably 1.000 μm or less. The lower limit of the value S of the arithmetic mean height (Sa) is not particularly limited, and may be 0.001 μm or more, 0.005 μm or more, or 0.010 μm or more.

[0124] From the viewpoint of the retention of the adherend during extension, the value S' of the arithmetic mean height (Sa) is preferably 5.000 μm or less, more preferably 2.000 μm or less, and further preferably 1.000 μm or less. The lower limit of the value S' of the arithmetic mean height (Sa) is not particularly limited, and may be 0.001 μm or more, 0.005 μm or more, or 0.010 μm or more.

[0125] From the viewpoint of the retention of the adherend during extension, the surface adhesive force (A' value) of the adhesive layer when the adhesive film is extended by 200% is preferably 20 gf or more, more preferably 40 gf or more, and further preferably 60 gf or more. The A' value may be 150 gf or less, 100 gf or less, or 50 gf or less.

[0126] From the viewpoint of adhesive strength, the adhesive strength (A value) of the surface of the adhesive layer before the adhesive film is stretched is preferably 20 gf or more, more preferably 40 gf or more, and further preferably 60 gf or more. The A value may be 200 gf or less, 150 gf or less, 100 gf or less, 80 gf or less, or 40 gf or less.

[0127] From the viewpoint of maintaining adhesive strength even during extension and suppressing adhesive residue on the adherend, the ratio A' / A of the adhesive film is preferably 0.5 or more, more preferably 0.7 or more, and even more preferably 1.0 or more.

[0128] Furthermore, the ratio A' / A of the adhesive film is preferably 7.0 or less, more preferably 5.0 or less, and further preferably 3.5 or less.

[0129] The measurement of the adhesive force in the present disclosure is described in the Examples.

[0130] <Method for producing adhesive film>

[0131] The adhesive film of the present disclosure can be manufactured by a known method. For example, the adhesive film can be manufactured by applying the adhesive layer forming composition to the substrate layer and drying. Alternatively, after applying the adhesive layer forming composition to a PET film subjected to a demolding treatment and drying to form an adhesive layer, the adhesive layer can be transferred to the substrate layer, and then the PET film can be peeled off to manufacture an adhesive film having an adhesive layer and a substrate layer laminated thereon.

[0132] The adhesive layer forming composition contains at least two polymers described above, and may further contain other resin components and other components added as desired.

[0133] [Preparation of Adhesive Layer-Forming Composition]

[0134] The preparation method of the adhesive layer forming composition is not particularly limited, and a known composition preparation method can be used. The solvent used in the preparation of the adhesive layer forming composition is not particularly limited, and is preferably an organic solvent that can dissolve the polymer. As the organic solvent, toluene, methyl ethyl ketone, ethyl acetate, etc. can be listed.

[0135] [Giving and drying]

[0136] The method of applying the adhesive layer forming composition to the substrate layer is not particularly limited, and known coating methods such as roll coating, bar coating, and lick coating can be used. The amount of the adhesive layer forming composition applied is preferably appropriately adjusted so that the thickness of the composition layer formed after drying is close to the target thickness of the adhesive layer.

[0137] The method of drying the applied adhesive layer-forming composition is not particularly limited, and a known drying method can be used. For example, the method may be a method of drying at 50° C. to 150° C. for 0.1 minute to 60 minutes.

[0138] <Application of adhesive film>

[0139] The adhesive film disclosed herein can be used in a method for manufacturing electronic components such as semiconductor chips and ceramic capacitors.

[0140] Specifically, it can be used in a step of arranging a plurality of semiconductor chips on an adhesive film and then extending the adhesive film to increase the interval between two adjacent semiconductor chips, or in a step of processing or picking up semiconductor chips.

[0141] The adhesive film in one embodiment of the present disclosure can maintain adhesive strength even when stretched and suppress adhesive residue on the adherend. Therefore, when a semiconductor chip is processed on the stretched adhesive film, the semiconductor chip can be held and adhesive residue on the semiconductor chip can be suppressed.

[0142] <Method for manufacturing semiconductor device>

[0143] In the method for manufacturing a semiconductor device of the present disclosure, a semiconductor device is manufactured using the adhesive film of the present disclosure. The adhesive film of the present disclosure can be used as a dicing film or a dicing die bonding film.

[0144] For example, the method for manufacturing a semiconductor device of the present disclosure includes: stretching the adhesive film of the present disclosure having a plurality of semiconductor chips arranged on one surface to increase the distance between two adjacent semiconductor chips. After stretching, the semiconductor chips can be peeled off from the adhesive film.

[0145] The plurality of semiconductor chips can be obtained by placing a wafer on the adhesive film of the present disclosure and singulating the wafer. Alternatively, semiconductor chips singulated in advance can be placed on the adhesive film of the present disclosure.

[0146] After the adhesive film is stretched and before the semiconductor chip is peeled off, a step of processing the semiconductor chip may be included. The processing may be to provide a functional layer. As the functional layer, an insulating layer may be mentioned.

[0147] Example

[0148] Hereinafter, the above-mentioned embodiment will be specifically described by way of examples, but the above-mentioned embodiment is not limited to these examples.

[0149] (Acrylic polymer 1)

[0150] The acrylic polymer 1, which is a copolymer of the following monomers, was used. The SP value of the acrylic polymer 1 was determined by the above method. The SP value of the acrylic polymer 1 was 10.3. The hydroxyl value was 2.5 mgKOH / g.

[0151] Butyl acrylate: 88.1 parts by mass

[0152] 2-Hydroxyethyl methacrylate: 0.6 parts by mass

[0153] Acrylonitrile: 11.2 parts by mass

[0154] The acrylic polymer 1 had an Mn of 140,000, an Mw of 910,000, and an Mw / Mn of 6.5.

[0155] (Acrylic polymer 2)

[0156] The acrylic polymer 2, which is a copolymer of the following monomers, was used. The SP value of the acrylic polymer 2 was 10.0, and the hydroxyl value was 31.1 mgKOH / g.

[0157] Butyl acrylate: 92.2 parts by mass

[0158] 4-Hydroxybutyl acrylate: 7.8 parts by mass

[0159] The Mn of the acrylic polymer 2 was 133,000, the Mw was 1,039,000, and the Mw / Mn was 7.8.

[0160] (Acrylic polymer 3)

[0161] The acrylic polymer 3, which is a copolymer of the following monomers, was used. The SP value of the acrylic polymer 3 was 10.1, and the hydroxyl value was 46.7 mgKOH / g.

[0162] Butyl acrylate: 88.7 parts by mass

[0163] 4-Hydroxybutyl acrylate: 11.3 parts by mass

[0164] The acrylic polymer 3 had an Mn of 130,000, an Mw of 1,040,000, and an Mw / Mn of 8.0.

[0165] (Acrylic polymer 4)

[0166] The acrylic polymer 4, which is a copolymer of the following monomers, was used. The SP value of the acrylic polymer 4 was 9.9, and the hydroxyl value was 15.6 mgKOH / g.

[0167] Butyl acrylate: 95.9 parts by mass

[0168] ·4-Hydroxybutyl acrylate: 4.1 parts by mass

[0169] The acrylic polymer 4 had an Mn of 130,000, an Mw of 1,040,000, and an Mw / Mn of 8.0.

[0170] (Acrylic polymer 5)

[0171] The acrylic polymer 5, which is a copolymer of the following monomers, was used. The SP value of the acrylic polymer 5 was 11.0, and the hydroxyl value was 19.5 mgKOH / g.

[0172] Butyl acrylate: 71.2 parts by mass

[0173] ·2-Hydroxyethyl methacrylate: 4.8 parts by mass

[0174] Acrylonitrile: 24.0 parts by mass

[0175] The Mn of acrylic polymer 5 was 140,000, the Mw was 610,000, and the Mw / Mn was 4.4.

[0176] (Synthesis of Acrylic Polymer 6)

[0177] The following components are copolymerized by solution polymerization to obtain a polymer.

[0178] 2-Hydroxyethyl acrylate: 25 parts by mass

[0179] ·2-Ethylhexyl acrylate: 75 parts by mass

[0180] After adding dibutylhydroxytoluene as a polymerization inhibitor and dioctyltin dilaurate as a urethanization catalyst to the obtained polymer, 16 parts by mass of 2-methacryloyloxyethyl isocyanate (KARENZ MOI manufactured by Showa Denko K.K.) was added to obtain acrylic polymer 6. The SP value of acrylic polymer 6 was 10.4. The hydroxyl value was 120.8 mgKOH / g.

[0181] The acrylic polymer 6 had an Mn of 140,000, an Mw of 500,000, and an Mw / Mn of 3.6.

[0182] (Preparation of Adhesive Layer-Forming Composition)

[0183] The acrylic polymer shown in the following Table 1 was dissolved in methyl ethyl ketone together with a crosslinking agent and a plasticizer to prepare a composition for forming an adhesive layer. The unit of the compounding amount in Table 1 is part by mass.

[0184] As a crosslinking agent, CORONATE L (manufactured by Tosoh Corporation, TMP adduct of tolylene diisocyanate) was used. The added amount was 2.2 parts (parts by mass) based on 100 parts of the total compounding amount of the acrylic polymer.

[0185] As a plasticizer, D-810 (manufactured by ADEKA Corporation, bis(2-ethylhexyl) terephthalate) was used, and the added amount was 20 parts (parts by mass) based on 100 parts of the total compounding amount of the acrylic polymer.

[0186] (Production of Adhesive Film)

[0187] The adhesive layer forming composition was applied to the release-treated surface of a 38 μm thick PET film on one side to a thickness of 20 μm after drying, and dried to form an adhesive layer. Next, the adhesive layer side of the PET film was attached to the single side of the substrate at room temperature (25° C.), the adhesive layer was transferred to the substrate by applying pressure with a rubber roller, and the PET film was peeled off to prepare an adhesive film having a substrate layer and an adhesive layer.

[0188] As the substrate (substrate layer), a polyvinyl chloride film (thickness 120 μm) containing 44% by mass of a plasticizer (P-200 manufactured by ADEKA Corporation) and 0.5% by mass of a pigment (phthalocyanine blue, maximum particle size 10 μm) was used.

[0189] (Measurement of surface roughness)

[0190] The arithmetic mean height (Sa) value S before elongation and the arithmetic mean height (Sa) value S' at 200% elongation were measured by the above method. The ratio S' / S was calculated from the measurement results and is shown in Table 2.

[0191] (Measurement of Viscosity)

[0192] The tack value A of the adhesive layer before the adhesive film is stretched 200% is measured by the following method.

[0193] The adhesive film was cut into a size of 20 mm in width and 100 mm in length, and placed in the measuring section of the viscosity tester with the adhesive layer facing upward. A Φ5 mm probe made of SUS was brought into contact with the adhesive layer at 23±5°C, and the probe was lowered, pressed, and raised under the conditions of a probe lowering speed of 120 mm / min, a load of 50 gf, a pressurizing time of 1 second, and a probe raising speed of 600 mm / min. The obtained value was taken as the viscosity value A.

[0194] The tack value A' of the adhesive layer when the adhesive film was stretched 200% was measured by the following method.

[0195] The adhesive film is stretched 200% by the above method, and the adhesive layer side of the adhesive film is pressed against a frame plate having a through hole of 10 mm in diameter. The frame plate with the adhesive film attached is set in a viscosity tester in such a way that the adhesive layer is the measuring side. A probe is arranged so as to penetrate the through hole, and the probe is lowered, pressurized, and raised, and the obtained value is taken as the viscosity value A'. The measuring conditions of the viscosity value A' are the same as those of the viscosity value A.

[0196] As a viscosity tester for measuring the viscosity value A and the viscosity value A′, for example, “probe viscosity tester TAC-II” manufactured by Rhesca Co., Ltd. can be used.

[0197] The ratio A' / A was calculated from the measurement results and is shown in Table 2.

[0198] (Evaluation of residual adhesive)

[0199] After laminating the adhesive film on the mirror-finished SUS plate, the adhesive film was peeled off by hand to confirm the presence of the resin component remaining on the surface of the SUS plate. Lamination was performed by applying it with a hand roller and then pressing it at 16 MPa for 5 minutes in a press machine heated to 80°C. The results are shown in Table 2.

[0200] [Table 1]

[0201]

[0202] [Table 2]

[0203]

[0204] As shown in Tables 1 and 2, Examples 1 to 3 in which (1) the ratio S' / S was 9.5 or less or (2) the difference in SP values ​​of the polymers contained in the adhesive layer was 0.3 or less and the hydroxyl value ratio was 40 or less had high adhesive strength during extension and no adhesive residue was observed.

[0205] In contrast, in Comparative Examples 1 to 5, (1') the ratio S' / S exceeded 9.5, or (2') the difference in SP values ​​of the polymers contained in the adhesive layer exceeded 0.3 or the hydroxyl value ratio exceeded 40, and the adhesive force during elongation became low. Although no adhesive residue was generated in Comparative Examples 2 to 4, adhesive residue was confirmed in Comparative Example 1.

[0206] Comparative Examples 6 and 7 used only one polymer, and although the decrease in adhesive force during elongation was suppressed, adhesive residue was generated. In Comparative Example 7, it was confirmed that the added components other than the polymer ooze out to the SUS plate.

[0207] The disclosure of Japanese Patent Application No. 2023-101235 is incorporated into the present disclosure in its entirety by reference.

[0208] All documents, patent applications, and technical standards in the present disclosure are hereby incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. An adhesive film comprising: an adhesive layer comprising two or more polymers and a substrate layer, A ratio S' / S of a value S' of an arithmetic mean height (Sa) of the surface of the adhesive layer when the adhesive film is stretched 200% to a value S of an arithmetic mean height (Sa) of the surface of the adhesive layer of the adhesive film before stretching is 9.5 or less.

2. The adhesive film according to claim 1, wherein The difference in SP values ​​between at least two of the two or more polymers is 0.3 or less.

3. The adhesive film according to claim 1, wherein The hydroxyl value ratio of at least two of the two or more polymers is 40 or less.

4. An adhesive film comprising: an adhesive layer comprising two or more polymers and a substrate layer, The difference in SP value between at least two of the two or more polymers is 0.3 or less, and the hydroxyl value ratio is 40 or less.

5. The adhesive film according to claim 1 or 4, wherein The value S of the arithmetic mean height (Sa) of the surface of the adhesive layer before extension is 0.001 μm to 5.000 μm.

6. The adhesive film according to claim 1 or 4, wherein The content of the polymer with the largest content in the adhesive layer is 85% by mass or less relative to the total content of the two or more polymers contained in the adhesive layer.

7. A method for manufacturing a semiconductor device, comprising: By stretching the adhesive film according to claim 1 or 4 in which a plurality of semiconductor chips are arranged on one surface, the interval between two adjacent semiconductor chips is increased.

8. The method for manufacturing a semiconductor device according to claim 7, comprising: After the elongation is performed, the semiconductor chip is peeled off from the adhesive film.

9. The method for manufacturing a semiconductor device according to claim 8, comprising: The semiconductor chip is processed after the elongation and before the semiconductor chip is peeled off.

10. The method for manufacturing a semiconductor device according to claim 9, wherein: The processing includes providing a functional layer on the semiconductor chip.

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