Adhesive resin film and method for manufacturing electronic device

Abstract

This adhesive resin film is provided with a base material layer, a concavo-convex absorptive resin layer, and an adhesive resin layer in this order, and is used to protect a circuit forming surface of an electronic component. The concavo-convex absorptive resin layer has a minimum value G'bmin of a storage elastic modulus G'b of 0.001 MPa or more and less than 0.1 MPa at 25°C or more and less than 250°C and has a storage elastic modulus G'b250 of 0.005 MPa to 0.3 MPa, inclusive, at 250°C.

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing an adhesive resin film and an electronic device. [Background technology]

[0002] Electronic devices are typically manufactured through a process of grinding the non-circuit-forming surface of a semiconductor wafer to reduce its thickness (back grinding process), and a process of forming electrodes on the non-circuit-forming surface of the ground semiconductor wafer by sputtering or other methods (back metal process). These steps are carried out with a surface protection film attached to the circuit-forming surface of the semiconductor wafer in order to prevent contamination of the circuit-forming surface of the semiconductor wafer by grinding dust and grinding water.

[0003] The surface protection film used in this manner is required to be able to conform well to the irregularities on the circuit-forming surface of the semiconductor wafer and to be able to be peeled off without leaving any adhesive residue.

[0004] For example, Patent Document 1 discloses a semiconductor wafer surface protection film having, in this order, a base layer A, an adhesive absorbing layer B, and an adhesive surface layer C, wherein the adhesive absorbing layer B is made of an adhesive composition containing a thermosetting resin b1, the adhesive absorbing layer B has a minimum storage modulus G'b of 0.001 MPa or more and less than 0.1 MPa in the temperature range of 25°C or more and less than 250°C, a storage modulus G'b250 of 0.005 MPa or more at 250°C, and the temperature at which G'bmin is exhibited is 50°C or more and 150°C or less, and the adhesive surface layer C has a minimum storage modulus G'c of 0.03 MPa or more, G'cmin, in the temperature range of 25°C or more and less than 250°C. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6404475 Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, electronic components have tended to become thinner. The inventors' research has revealed that, as electronic components become thinner, conventional semiconductor wafer surface protection films tend to warp when thermally curing the surface protection film after application to the non-circuit-forming surface of the electronic component, or after a back-grinding process. Warping is particularly likely to occur in wafer-level chip-size packages (WLCSPs) where the encapsulating resin and semiconductor are integrated and the encapsulating resin is relatively thick. Warping of electronic components can make them difficult to handle and can cause cracks in the electrodes.

[0007] The present invention has been made in view of the above circumstances, and provides an adhesive resin film capable of suppressing warpage of electronic components (such as wafers) and a method for manufacturing an electronic device. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above problems, and as a result, have discovered an adhesive resin film that is used to protect the circuit-forming surface of an electronic component, and that includes a base layer, a roughness-absorbing resin layer, and an adhesive resin layer in this order, and that the roughness-absorbing resin layer has a storage modulus G' at 25°C or higher and lower than 250°C. b The minimum value of is within a specific range, and the storage modulus G' at 250°C is b250 The inventors have found that warping of electronic components can be suppressed by using an adhesive resin film having a specific range of σ, and have completed the present invention.

[0009] That is, according to the present invention, there are provided the following adhesive resin film and a method for manufacturing an electronic device using the adhesive resin film.

[0010] [1] An adhesive resin film used to protect a circuit-forming surface of an electronic component, the adhesive resin film comprising a base layer, an irregularity-absorbing resin layer, and an adhesive resin layer in this order, The storage modulus G' of the irregularity-absorbing resin layer in the range of 25°C or higher and lower than 250°C b The minimum value of G' bmin is 0.001 MPa or more and less than 0.1 MPa, and the storage modulus G' at 250 ° C. b250 An adhesive resin film having a compressive strength of 0.005 MPa or more and 0.3 MPa or less. [2] The adhesive resin film according to the above [1], The adhesive resin film has a loss tangent tanδ of the irregularity-absorbing resin layer at 250°C of 0.05 or more and 1.2 or less. [3] The adhesive resin film according to the above [1] or [2], Storage modulus G' of the uneven absorbent resin layer at 30°C b30 An adhesive resin film having a compressive strength of 0.1 MPa or more. [4] The adhesive resin film according to any one of the above [1] to [3], The adhesive resin film, wherein the irregularity-absorbing resin layer is a layer containing a crosslinkable resin. [5] The adhesive resin film according to [4] above, The pressure-sensitive adhesive resin film, wherein the crosslinkable resin comprises at least one selected from the group consisting of an ethylene-α-olefin copolymer and an ethylene-vinyl ester copolymer. [6] The adhesive resin film according to [5] above, The adhesive resin film, wherein the ethylene-vinyl ester copolymer comprises an ethylene-vinyl acetate copolymer. [7] The adhesive resin film according to any one of the above [1] to [6], Bag grinding tape is an adhesive resin film. [8] The adhesive resin film according to any one of the above [4] to [7], An adhesive resin film, wherein the unevenness-absorbing resin layer further contains a crosslinking aid. [9] The adhesive resin film according to [8] above, The crosslinking aid comprises one or more compounds selected from the group consisting of benzophenone compounds, divinyl aromatic compounds, cyanurate compounds, diallyl compounds, acrylate compounds, triallyl compounds, oxime compounds, and maleimide compounds.

[10] The adhesive resin film according to any one of the above [1] to [9], An adhesive resin film, wherein the resin constituting the base layer comprises one or more members selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide.

[11] The adhesive resin film according to any one of the above [1] to

[10] , An adhesive resin film, wherein the resin constituting the base layer contains polyethylene naphthalate.

[12] The adhesive resin film according to any one of the above [1] to

[11] , The thickness of the irregularity-absorbing resin layer of the adhesive resin film is 10 μm or more and 1000 μm or less.

[13] The adhesive resin film according to any one of the above [1] to

[12] , An adhesive resin film, wherein the adhesive constituting the adhesive resin layer comprises one or more adhesives selected from (meth)acrylic adhesives, silicone adhesives, urethane adhesives, olefin adhesives, and styrene adhesives.

[14] a preparation step (A) of preparing a structure including an electronic component having a circuit formation surface, an adhesive laminate film attached to the circuit formation surface of the electronic component, and a thermosetting protective film attached to a surface of the electronic component opposite to the circuit formation surface; a heat curing step (B) of heat curing the thermosetting protective film by heating the structure; A method for manufacturing an electronic device comprising: A method for producing an electronic device, wherein the adhesive laminate film is the adhesive resin film according to any one of the above [1] to

[13] .

[15] A method for manufacturing an electronic device according to the above

[14] , The above step (A) a curing step of thermally curing or ultraviolet curing the irregularity-absorbing resin layer of the adhesive film in a state where the adhesive resin film is attached to the circuit-forming surface of the electronic component; attaching the thermosetting protective film to a surface of the electronic component opposite to the circuit-forming surface; A method for manufacturing an electronic device, comprising:

[16] A method for manufacturing an electronic device according to the above

[15] , A method for manufacturing an electronic device, wherein the heating temperature in the step of attaching the thermosetting protective film to the surface of the electronic component opposite to the circuit formation surface is 50°C or higher and 90°C or lower.

[17] A method for manufacturing an electronic device according to the above

[15] or

[16] , The method for manufacturing an electronic device includes a back-grinding step in which, before the curing step, the adhesive resin film is attached to the circuit-forming surface of the electronic component, and the surface of the electronic component opposite the circuit-forming surface is back-grinded.

[18] A method for manufacturing an electronic device according to any one of the above items

[14] to

[17] , A method for producing an electronic device, wherein the heating temperature in step (B) is 120°C or higher and 170°C or lower.

[19] A method for manufacturing an electronic device according to any one of the above

[14] to

[18] , The method for manufacturing an electronic device, wherein the circuit formation surface of the electronic component includes bump electrodes.

[20]

[19] A method for manufacturing an electronic device according to

[19] , In the method for manufacturing an electronic device, when the height of the bump electrode is H [μm] and the thickness of the irregularity-absorbing resin layer is d [μm], H / d is 0.01 or more and 1 or less. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an adhesive resin film capable of suppressing warpage of electronic components (such as wafers) and a method for manufacturing an electronic device. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing an example of an adhesive resin film according to an embodiment of the present invention. [Figure 2] 1A to 1C are cross-sectional views schematically illustrating an example of a method for manufacturing an electronic device according to an embodiment of the present invention. [Figure 3] 1 is a graph showing the relationship between temperature and storage modulus G′ b in Examples 1 to 3 and Comparative Examples 1 to 4. FIG. [Figure 4] 1 is a diagram showing the relationship between temperature and loss tangent tan δ in Examples 1 to 3 and Comparative Examples 1 to 4. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all drawings, similar components are given the same reference numerals and their explanation will be omitted where appropriate. The drawings are schematic and do not correspond to the actual dimensional ratios. Unless otherwise specified, the numerical range "A to B" represents A or more and B or less. In the embodiments, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

[0014] As described above, the inventors' investigations have revealed that, as the thickness of electronic components decreases, conventional semiconductor wafer surface protection films tend to cause warpage in electronic components when thermally curing the surface protection film after application to the circuit-forming surface of the electronic components or after a back-grinding process. Warpage is particularly likely to occur when the resin and semiconductor are integrated, as in WLCSP, and the resin is relatively thick. Warpage in electronic components can make them difficult to handle and can cause cracks in the electrodes.

[0015] The present inventors have conducted extensive research to solve the above problems, and as a result, have discovered an adhesive resin film that is used to protect the circuit-forming surface of an electronic component, and that includes a base layer, a roughness-absorbing resin layer, and an adhesive resin layer in this order, and that the roughness-absorbing resin layer has a storage modulus G' at 25°C or higher and lower than 250°C. b The minimum value of G' bmin is 0.001 MPa or more and less than 0.1 MPa, and the storage modulus G' at 250 ° C. b250 It has become clear that an adhesive resin film having a compressive strength of 0.005 MPa or more and 0.3 MPa or less can suppress warpage of electronic components.

[0016] FIG. 1 is a cross-sectional view schematically showing an example of the adhesive resin film according to this embodiment. The adhesive resin film 50 according to this embodiment (hereinafter also referred to as "adhesive laminate film 50") comprises, in this order, a base layer 20, an irregularity-absorbing resin layer 30, and an adhesive resin layer 40. The adhesive resin film 50 is used to protect the circuit-forming surface of an electronic component.

[0017] The storage modulus of the irregularity-absorbing resin layer is measured under the following conditions. Measurement mode: Dynamic viscoelasticity measurement mode Frequency: 6.28Hz Heating rate: 3℃ / min Temperature range: 0℃~250℃ Viscoelastic sample preparation method: {In the case of ethylene vinyl acetate} After impregnating the pellets with the additive, the pellets are melted on a 25 mm diameter parallel plate stage heated to 100°C, and the stage gap is adjusted to a thickness of approximately 500 μm to form a film on the stage.The temperature is then lowered to 0°C and held for 5 minutes before measurements can be performed. {For acrylic interlayer} In the case of acrylic interlayers, measurements can be made with the prepared layer.

[0018] The adhesive resin film 50 of this embodiment is used in the manufacturing process of electronic devices to protect the surfaces of electronic components, fix electronic components, form electrodes, etc. More specifically, it can be suitably used as a backgrinding tape used to protect the circuit formation surface (i.e., the circuit surface including the circuit pattern) of electronic components in the process of grinding electronic components (also called the backgrinding process), which is one of the manufacturing processes of electronic devices, or in the process of forming electrodes by sputtering or the like on the non-circuit formation surface of a semiconductor wafer after grinding (backmetal process).

[0019] The adhesive resin film 50 according to this embodiment can be used as an adhesive film for protecting and holding electronic components (e.g., semiconductor wafers, sealing wafers, etc.) having surface irregularities in a dicing process, a transfer process, etc.; an adhesive film for temporarily fixing electronic components (e.g., semiconductor chips, semiconductor packages, etc.) having surface irregularities; or a film for use in heating processes at 90°C or higher, such as dry polishing of electronic components (e.g., semiconductor wafers, etc.), attachment and curing of back surface protection members for electronic components (e.g., semiconductor wafers, etc.), formation of electromagnetic wave shielding films on electronic components (e.g., semiconductor packages, etc.), and formation of metal films on the back surfaces of electronic components (e.g., semiconductor wafers, etc.).

[0020] <Base material layer> The base layer 20 is a layer provided for the purpose of improving the properties of the adhesive resin film 50, such as ease of handling, mechanical properties, and heat resistance. The base layer 20 is not particularly limited, and examples thereof include a resin film and a metal foil.

[0021] Examples of resins that may constitute the base layer 20 include one or more selected from polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins; polyimide (PI); polyether ether ketone (PEEK); polyvinyl chloride resins such as polyvinyl chloride (PVC); polyvinylidene chloride resins; polyamide resins; polyurethane; polystyrene resins; acrylic resins; fluororesins; cellulose resins; polycarbonate resins, etc.

[0022] Among these, the melting point of the resin constituting the base layer 20 is preferably 250°C or higher, more preferably 265°C or higher, due to its high heat resistance. The melting point can be measured by differential scanning calorimetry (DSC). From the viewpoint of further improving heat resistance, the resin constituting such base layer 20 preferably contains one or more types selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide, and more preferably contains polyethylene naphthalate.

[0023] The base layer 20 may be a single layer or two or more layers. The resin film used to form the base layer 20 may be in the form of a stretched film, or a uniaxially or biaxially stretched film.

[0024] The thickness of the base layer 20 is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. By making the thickness of the base layer 20 at a certain level or more, it becomes easier to attach an adhesive resin film. In addition, it becomes easier to stably hold electronic components (e.g., semiconductor wafers) when grinding the electronic components. The thickness of the base layer 20 is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less. By setting the thickness of the base layer 20 to a certain level or less, workability in peeling off the adhesive resin film becomes easier.

[0025] The substrate layer 20 may be subjected to a surface treatment to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.

[0026] <Roughness-absorbing resin layer> The adhesive resin film 50 according to this embodiment includes an irregularity-absorbing resin layer 30 between a base material layer 20 and an adhesive resin layer 40 . The irregularity-absorbing resin layer 30 is a layer provided for the purpose of improving the conformability of the adhesive resin film 50 to the circuit formation surface and improving the adhesion between the circuit formation surface and the adhesive resin film 50. Storage modulus G' of the irregularity-absorbing resin layer 30 in the range of 25°C or higher and lower than 250°C b The minimum value of G' bmin is 0.001 MPa or more, preferably 0.002 MPa or more, and more preferably 0.003 MPa or more. In addition, the G' of the irregularity-absorbing resin layer 30 in the range of 25°C or more and less than 250°C bmin is less than 0.1 MPa, preferably less than 0.08 MPa, more preferably less than 0.05 MPa, even more preferably less than 0.02 MPa, even more preferably less than 0.01 MPa, even more preferably less than 0.008 MPa, even more preferably less than 0.006 MPa, even more preferably less than 0.005 MPa. G' of the irregularity-absorbing resin layer 30 in the range of 25°C or more and less than 250°C bmin By ensuring that the film has a surface roughness within the above range, it is possible to improve the film's ability to conform to unevenness and to prevent the film from lifting during high-temperature processes. Furthermore, even when the film undergoes high-temperature processes such as a back metal process, cracking of electronic components and adhesive residue during peeling can be prevented. In addition, the storage modulus G' of the irregularity-absorbing resin layer 30 at 250°C b250The storage modulus G' at 250°C is 0.005 MPa or more and 0.3 MPa or less, preferably 0.007 MPa or more and 0.25 MPa or less, more preferably 0.01 MPa or more and 0.2 MPa or less, even more preferably 0.02 MPa or more and 0.18 MPa or less, even more preferably 0.025 MPa or more and 0.18 MPa or less, and even more preferably 0.03 MPa or more and 0.17 MPa or less. b250 When the thickness is within the above range, warpage of the electronic component can be suppressed.

[0027] The loss tangent tanδ of the irregularity-absorbing resin layer 30 at 250°C is preferably 0.05 or more and 1.2 or less, more preferably 0.05 or more and 1.0 or less, even more preferably 0.06 or more and 0.5 or less, and even more preferably 0.06 or more and 0.3 or less. If the loss tangent tanδ is within the above range, bleeding of the irregularity-absorbing resin layer can be suppressed.

[0028] In addition, the storage modulus G' of the irregularity absorbent resin layer 30 at 30°C b30 is preferably 0.1 MPa or more, more preferably 0.15 MPa or more, even more preferably 0.3 MPa or more, even more preferably 0.5 MPa or more, and even more preferably 0.8 MPa or more, and is, for example, 2 MPa or less, preferably 1.5 MPa or less, and more preferably 1.3 MPa or less. b30 If is equal to or greater than the above value, warping of the electronic component and bleeding of the irregularity-absorbing resin layer can be further suppressed.

[0029] The material of the irregularity-absorbing resin layer 30 is not particularly limited, but may be, for example, one or more types selected from polyolefin-based resins and polystyrene-based resins.

[0030] Among these, the irregularity-absorbing resin layer 30 is preferably a layer containing a crosslinkable resin having a melting point of 40° C. or more and 80° C. or less. The melting point of the crosslinkable resin can be measured by a differential scanning calorimeter (DSC).

[0031] The inclusion of a crosslinkable resin in the irregularity-absorbing resin layer 30 allows for effective thermal curing or ultraviolet curing, further improving the heat resistance of the irregularity-absorbing resin layer 30. This further prevents the irregularity-absorbing resin layer 30 from melting and causing resin extrusion in the step of attaching a thermosetting protective film to the surface opposite the circuit-forming surface of the electronic component or in the step of thermally curing the thermosetting protective film.

[0032] The crosslinkable resin according to the present embodiment is not particularly limited as long as it can form the roughness-absorbing resin layer 30 and can be crosslinked by heat, ultraviolet light, or the like to improve its heat resistance. Examples of the crosslinkable resin include ethylene-α-olefin copolymers containing ethylene and an α-olefin having 3 to 20 carbon atoms, high-density ethylene resins, low-density ethylene resins, medium-density ethylene resins, very-low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, propylene (copolymers), 1-butene (copolymers), 4-methylpentene-1 (copolymers), olefin resins such as ethylene-cyclic olefin copolymers, ethylene-α-olefin-cyclic olefin copolymers, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-aromatic vinyl copolymers, and ethylene-α-olefin-aromatic vinyl copolymers; ethylene-carboxylic acid anhydride copolymers such as ethylene-unsaturated carboxylic anhydride copolymers and ethylene-α-olefin-unsaturated carboxylic anhydride copolymers; and ethylene-epoxy copolymers such as ethylene-epoxy-containing unsaturated compound copolymers and ethylene-α-olefin-epoxy-containing unsaturated compound copolymers. Silicon-based copolymers; ethylene-(meth)acrylate copolymers such as ethylene-ethyl (meth)acrylate copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-propyl (meth)acrylate copolymer, ethylene-butyl (meth)acrylate copolymer, ethylene-hexyl (meth)acrylate copolymer, ethylene-2-hydroxyethyl (meth)acrylate copolymer, ethylene-2-hydroxypropyl (meth)acrylate copolymer, and ethylene-glycidyl (meth)acrylate copolymer; ethylene-ethylenically unsaturated acid copolymers such as ethylene-(meth)acrylic acid copolymer, ethylene-maleic acid copolymer, ethylene-fumaric acid copolymer, and ethylene-crotonic acid copolymer; ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, and ethylene-vinyl stearate copolymer; ethylene-styrene copolymers; unsaturated carboxylic acid ester copolymers such as (meth)acrylate ester copolymers; ionomer resins such as ethylene-metal acrylate copolymer and ethylene-metal methacrylate copolymer;One or more materials selected from the group consisting of urethane-based resins, silicone-based resins, acrylic acid-based resins, methacrylic acid-based resins, cyclic olefin (co)polymers, α-olefin-aromatic vinyl compound-aromatic polyene copolymers, ethylene-α-olefin-aromatic vinyl compound, aromatic polyene copolymers, ethylene-aromatic vinyl compound-aromatic polyene copolymers, styrene-based resins, acrylonitrile-butadiene-styrene copolymers, styrene-conjugated diene copolymers, acrylonitrile-styrene copolymers, acrylonitrile-ethylene-α-olefin-non-conjugated polyene-styrene copolymers, acrylonitrile-ethylene-α-olefin-conjugated polyene-styrene copolymers, methacrylic acid-styrene copolymers, ethylene terephthalate resins, fluororesins, polyester carbonates, polyvinyl chloride, polyvinylidene chloride, polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, 1,2-polybutadiene-based thermoplastic elastomers, trans-polyisoprene-based thermoplastic elastomers, chlorinated polyethylene-based thermoplastic elastomers, liquid crystalline polyesters, and polylactic acid can be used. ;

[0033] Among these, because crosslinking with a crosslinking agent such as an organic peroxide is easily achieved, it is preferable to use one or more selected from the group consisting of ethylene-α-olefin copolymers composed of ethylene and an α-olefin having 3 to 20 carbon atoms, low-density ethylene resins, medium-density ethylene resins, very-low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, olefin-based resins such as ethylene-cyclic olefin copolymers, ethylene-α-olefin-cyclic olefin copolymers, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-aromatic vinyl copolymers, and ethylene-α-olefin-aromatic vinyl copolymers; ethylene-unsaturated carboxylic acid anhydride copolymers, ethylene-α-olefin-unsaturated carboxylic acid anhydride copolymers, ethylene-epoxy-containing unsaturated compound copolymers, ethylene-α-olefin-epoxy-containing unsaturated compound copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, and ethylene-methacrylic acid copolymers; and 1,2-polybutadiene-based thermoplastic elastomers as the crosslinkable resin according to the present embodiment. The crosslinkable resin according to this embodiment is more preferably one or more selected from the group consisting of ethylene-α-olefin copolymers composed of ethylene and an α-olefin having 3 to 20 carbon atoms, low-density ethylene resins, very low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-unsaturated carboxylic anhydride copolymers, ethylene-α-olefin-unsaturated carboxylic anhydride copolymers, ethylene-epoxy-containing unsaturated compound copolymers, ethylene-α-olefin-epoxy-containing unsaturated compound copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, and ethylene-unsaturated carboxylic acid copolymers such as ethylene-methacrylic acid copolymers. As the crosslinkable resin according to the present embodiment, it is more preferable to use one or more resins selected from the group consisting of ethylene-α-olefin copolymers composed of ethylene and an α-olefin having 3 to 20 carbon atoms, low-density ethylene resins, very low-density ethylene resins, linear low-density polyethylene (LLDPE) resins, ethylene-α-olefin-non-conjugated polyene copolymers, ethylene-α-olefin-conjugated polyene copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-methacrylic acid copolymers, and other ethylene-unsaturated carboxylic acid copolymers. Among these, the crosslinkable resin according to the present embodiment is more preferably at least one selected from the group consisting of ethylene-α-olefin copolymers and ethylene-vinyl ester copolymers, even more preferably at least one selected from the group consisting of ethylene-α-olefin copolymers and ethylene-vinyl acetate copolymers, and even more preferably ethylene-vinyl acetate copolymers. Note that in the present embodiment, the above-mentioned resins may be used alone or in a blend.

[0034] The α-olefin in the ethylene-α-olefin copolymer, which is composed of ethylene and an α-olefin having 3 to 20 carbon atoms and is used as the crosslinkable resin in this embodiment, can typically be a single α-olefin having 3 to 20 carbon atoms, or a combination of two or more α-olefins having 3 to 20 carbon atoms. Among these, α-olefins having 10 or fewer carbon atoms are preferred, and α-olefins having 3 to 8 carbon atoms are particularly preferred. Examples of such α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene. Among these, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred due to their availability. The ethylene-α-olefin copolymer may be a random copolymer or a block copolymer, but a random copolymer is preferred from the viewpoint of flexibility.

[0035] Furthermore, it is preferable that the irregularity-absorbing resin layer 30 further contains a crosslinking agent. By including a crosslinking agent in the irregularity-absorbing resin layer 30, the irregularity-absorbing resin layer 30 can be more effectively thermally or ultraviolet-cured before the step (B) described below, thereby further improving the heat resistance of the irregularity-absorbing resin layer 30. This further reduces warping of the electronic component in the step (A2) of attaching a thermosetting protective film to the surface opposite the circuit-forming surface of the electronic component and the thermal curing step (B) of thermally curing the thermosetting protective film 70, described below. Furthermore, melting of the irregularity-absorbing resin layer 30 and resin extrusion can be further reduced in the step (A2) of attaching a thermosetting protective film to the surface opposite the circuit-forming surface of the electronic component and the thermal curing step (B) of thermally curing the thermosetting protective film. The crosslinking agent according to the present embodiment is not particularly limited, but for example, an organic peroxide or a photocrosslinking initiator can be used. The content of the crosslinking agent in the irregularity-absorbing resin layer 30 is preferably 2.0 parts by mass or less, more preferably 1.0 part by mass or less, and even more preferably 0.5 part by mass or less, per 100 parts by mass of the crosslinkable resin. Furthermore, the content of the crosslinking agent in the unevenness-absorbing resin layer 30 is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the crosslinkable resin.

[0036] Examples of organic peroxides include dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, dibenzoyl peroxide, cyclohexanone peroxide, di-t-butylperphthalate, cumene hydroperoxide, t-butyl hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and t-amyl Peroxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleic acid, 1,1-di(t-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(t-amylperoxy)cyclohexane, t-amylperoxyisononanoate, t-amylperoxynormaloctoate, 1,1-di(t-butylperoxy)-3,3,5-trimethylcyclohexane One or more compounds selected from the group consisting of methylcyclohexane, 1,1-di(t-butylperoxy)cyclohexane, t-butylperoxyisopropyl carbonate, t-butylperoxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-amyl peroxybenzoate, t-butyl peroxyacetate, t-butyl peroxyisononanoate, t-butyl peroxybenzoate, 2,2-di(butylperoxy)butane, n-butyl-4,4-di(t-butylperoxy)butyrate, methyl ethyl ketone peroxide, ethyl-3,3-di(t-butylperoxy)butyrate, dicumyl peroxide, t-butylcumyl peroxide, t-butyl peroxybenzoate, di-t-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and acetylacetone peroxide can be used.

[0037] Among these, it is preferable to use one or more selected from 2,5-dimethyl-2,5-di(t-butylperoxy)hexene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, t-butylperoxy-2-ethylhexyl carbonate, and t-butylperoxybenzoate.

[0038] The photocrosslinking initiator may be, for example, one or more selected from the group consisting of benzophenone, benzophenone derivatives, thioxanthone, thioxanthone derivatives, benzoin, benzoin derivatives, α-hydroxyalkylphenones, α-aminoalkylphenols, acylphosphinoxides, alkylphenylglucoxylates, diethoxyacetophenone, oxime esters, titanocene compounds, and anthraquinone derivatives. Among these, benzophenone, benzophenone derivatives, benzoin, benzoin derivatives, α-hydroxyalkylphenones, oxime esters, and anthraquinone derivatives are preferred because of their better crosslinkability, benzophenone, benzophenone derivatives, and anthraquinone derivatives are more preferred, and benzophenone and benzophenone derivatives are even more preferred because of their good transparency. Preferred examples of benzophenone and benzophenone derivatives include benzophenone, 4-phenylbenzophenone, 4-phenoxybenzophenone, 4,4-bis(diethylamino)benzophenone, methyl o-benzoylbenzoate, 4-methylbenzophenone, and 2,4,6-trimethylbenzophenone. Preferred examples of the anthraquinone derivative include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone.

[0039] Moreover, from the viewpoint of further improving heat resistance, the irregularity-absorbing resin layer 30 preferably further contains a cross-linking aid. The crosslinking aid may be, for example, one or more compounds selected from the group consisting of benzophenone compounds, divinyl aromatic compounds, cyanurate compounds, diallyl compounds, acrylate compounds, triallyl compounds, oxime compounds, and maleimide compounds. The content of the cross-linking aid in the unevenness-absorbing resin layer 30 is preferably 5.0 parts by mass or less, more preferably 2.0 parts by mass or less, even more preferably 1.0 part by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.3 parts by mass or less, per 100 parts by mass of the cross-linkable resin. Furthermore, the content of the cross-linking aid in the unevenness-absorbing resin layer 30 is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.10 parts by mass or more, and even more preferably 0.15 parts by mass or more, per 100 parts by mass of the cross-linkable resin.

[0040] The benzophenone compound includes, for example, 4-methylbenzophenone. Examples of the divinyl aromatic compound include divinylbenzene and di-i-propenylbenzene. Examples of the cyanurate compound include triallyl cyanurate and triallyl isocyanurate. An example of the diallyl compound is diallyl phthalate. An example of the triallyl compound is pentaerythritol triallyl ether. Examples of the acrylate compound include diethylene glycol diacrylate, triethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, and tetramethylolmethane tetra(meth)acrylate. Examples of the oxime compound include p-quinonedioxime, p-p'-dibenzoyl oxime, Nondioxime and the like. An example of the maleimide compound is m-phenylenedimaleimide. Among these, the crosslinking aid is preferably a cyanurate compound, more preferably at least one selected from triallyl cyanurate and triallyl isocyanurate, and even more preferably triallyl isocyanurate.

[0041] The thickness of the irregularity-absorbing resin layer 30 is not particularly limited as long as it is thick enough to fill in the irregularities on the circuit-forming surface of the electronic component, but for example, it is preferably 10 μm or more and 1000 μm or less, more preferably 20 μm or more and 900 μm or less, even more preferably 30 μm or more and 800 μm or less, even more preferably 50 μm or more and 700 μm or less, even more preferably 100 μm or more and 700 μm or less, even more preferably 300 μm or more and 600 μm or less, and even more preferably 400 μm or more and 600 μm or less.

[0042] When the height of the bump electrode present on the circuit formation surface of the electronic component is H [μm] and the thickness of the irregularity-absorbing resin layer 30 is d [μm], H / d is preferably 1 or less, more preferably 0.85 or less, and even more preferably 0.7 or less. When H / d is equal to or less than the upper limit, the thickness of the adhesive resin film can be made thinner while improving the irregularity absorbency. The lower limit of H / d is not particularly limited, but is, for example, 0.01 or more. The height of the bump electrode is generally 2 μm or more and 600 μm or less.

[0043] <Adhesive resin layer> The adhesive resin layer 40 is a layer provided on one side of the unevenness-absorbing resin layer 30, and is a layer that comes into contact with and adheres to the circuit-forming surface of the electronic component when the adhesive resin film is attached to the circuit-forming surface of the electronic component.

[0044] Examples of adhesives constituting the adhesive resin layer 40 include (meth)acrylic adhesives, silicone adhesives, urethane adhesives, olefin adhesives, and styrene adhesives. These may be used alone or in combination. Among these, (meth)acrylic adhesives using a (meth)acrylic polymer as the base polymer are preferred because they allow for easy adjustment of adhesive strength.

[0045] Furthermore, a radiation-crosslinkable adhesive, whose adhesive strength is reduced by radiation, can also be used as the adhesive constituting the adhesive resin layer 40. The adhesive resin layer 40 made of a radiation-crosslinkable adhesive is crosslinked by irradiation with radiation and its adhesive strength is significantly reduced, so that the electronic component can be easily peeled off from the adhesive resin layer 40 in step (C) of peeling the electronic component from the adhesive resin film, which will be described later. Examples of radiation include ultraviolet rays, electron beams, and infrared rays. As the radiation crosslinkable pressure sensitive adhesive, an ultraviolet crosslinkable pressure sensitive adhesive is preferred.

[0046] Examples of the (meth)acrylic polymer contained in the (meth)acrylic pressure-sensitive adhesive include a homopolymer of a (meth)acrylic acid ester compound and a copolymer of a (meth)acrylic acid ester compound and a comonomer. Examples of the (meth)acrylic acid ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate. These (meth)acrylic acid ester compounds may be used alone or in combination of two or more. Examples of comonomers constituting the (meth)acrylic copolymer include vinyl acetate, (meth)acrylonitrile, styrene, (meth)acrylic acid, itaconic acid, (meth)acrylamide, methylol (meth)acrylamide, maleic anhydride, etc. These comonomers may be used alone or in combination of two or more.

[0047] The radiation crosslinkable pressure-sensitive adhesive contains, for example, the above-mentioned (meth)acrylic polymer, a crosslinkable compound (a component having a carbon-carbon double bond), and a photopolymerization initiator or a thermal polymerization initiator.

[0048] Examples of crosslinkable compounds include monomers, oligomers, or polymers having a carbon-carbon double bond in the molecule and capable of being crosslinked by radical polymerization. Examples of such crosslinkable compounds include esters of (meth)acrylic acid and polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate; ester (meth)acrylate oligomers; isocyanurates or isocyanurate compounds such as 2-propenyldi-3-butenyl cyanurate, 2-hydroxyethylbis(2-(meth)acryloxyethyl)isocyanurate, tris(2-methacryloxyethyl)isocyanurate, and methacryloyloxyethyl isocyanate. When the (meth)acrylic polymer is a radiation-crosslinked polymer having a carbon-carbon double bond in the side chain of the polymer, it is not necessary to add a crosslinking compound.

[0049] The content of the crosslinkable compound is preferably 1 to 200 parts by mass, more preferably 2 to 100 parts by mass, and even more preferably 5 to 50 parts by mass, relative to 100 parts by mass of the (meth)acrylic polymer. When the content of the crosslinkable compound is within the above range, adjustment of adhesive strength becomes easier than when the content is less than the above range, and deterioration of storage stability due to excessive sensitivity to heat and light is less likely to occur than when the content is more than the above range.

[0050] The photopolymerization initiator may be any compound that cleaves upon irradiation with radiation to generate radicals, and examples thereof include benzoin alkyl ethers such as benzoin methyl ether, benzoin isopropyl ether, and benzoin isobutyl ether; aromatic ketones such as benzil, benzoin, benzophenone, and α-hydroxycyclohexyl phenyl ketone; aromatic ketals such as benzil dimethyl ketal; polyvinyl benzophenone; and thioxanthones such as chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, and diethylthioxanthone.

[0051] Examples of the thermal polymerization initiator include organic peroxide derivatives and azo-based polymerization initiators. Organic peroxide derivatives are preferred because they do not generate nitrogen during heating. Examples of the thermal polymerization initiator include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxydicarbonates.

[0052] A crosslinking agent may be added to the adhesive. Examples of the crosslinking agent include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, and diglycerol polyglycidyl ether; aziridine compounds such as tetramethylolmethane-tri-β-aziridinyl propionate, trimethylolpropane-tri-β-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide), and N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide); tetramethylolmethane-tri-β-aziridinyl propionate, trimethylolpropane-tri-β-aziridinyl propionate, N,N'-diphenylmethane-4,4'-bis(1-aziridinecarboxamide); and N,N'-hexamethylene-1,6-bis(1-aziridinecarboxamide). Examples of the acrylic acid include isocyanate compounds such as methylene diisocyanate, hexamethylene diisocyanate, and polyisocyanate; and esters of (meth)acrylic acid and polyhydric alcohols such as trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate. From the viewpoint of improving the balance between the heat resistance and adhesion of the adhesive resin layer 40, the content of the crosslinking agent is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, even more preferably 1 part by mass or more and 10 parts by mass or less, and even more preferably 5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic polymer.

[0053] The thickness of the adhesive resin layer 40 is not particularly limited, but is preferably, for example, 1 μm to 100 μm, more preferably 3 μm to 50 μm, and even more preferably 5 μm to 20 μm.

[0054] The adhesive resin layer 40 can be formed, for example, by applying an adhesive coating liquid onto the irregularity-absorbing resin layer 30 . The adhesive coating liquid can be applied by conventional coating methods such as roll coating, reverse roll coating, gravure roll coating, bar coating, comma coating, and die coating. The drying conditions for the applied adhesive are not particularly limited, but it is generally preferable to dry the applied adhesive at a temperature of 80 to 200°C for 10 seconds to 10 minutes. It is more preferable to dry the applied adhesive at 80 to 170°C for 15 seconds to 5 minutes. To sufficiently promote the crosslinking reaction between the crosslinking agent and the adhesive, the adhesive coating liquid may be heated at 40 to 80°C for approximately 5 to 300 hours after drying.

[0055] When the adhesive resin film of this embodiment is to be UV-cured to the roughness-absorbing resin layer 30 or UV-crosslinked to the adhesive resin layer 40, it is preferable that the adhesive resin film has a light transmittance to such an extent that the curing or crosslinking does not interfere with the purpose of the present invention.

[0056] The overall thickness of the adhesive resin film according to this embodiment is preferably 25 μm or more and 1100 μm or less, more preferably 100 μm or more and 900 μm or less, even more preferably 200 μm or more and 800 μm or less, even more preferably 300 μm or more and 700 μm or less, and even more preferably 400 μm or more and 600 μm or less, in terms of the balance between mechanical properties and handling.

[0057] The pressure-sensitive adhesive resin film according to this embodiment may have an adhesive layer (not shown) between each layer, which can improve the adhesion between the layers.

[0058] Next, an example of a method for producing the adhesive laminated material according to this embodiment will be described. First, an irregularity-absorbing resin layer 30 is formed by extrusion lamination on one surface of the base layer 20. Next, an adhesive coating liquid is applied onto the irregularity-absorbing resin layer 30 and dried to form an adhesive resin layer 40, thereby obtaining an adhesive laminate film 50. The base material layer 20 and the irregularity-absorbing resin layer 30 may be formed by co-extrusion molding, or may be formed by laminating a film-like base material layer 20 and a film-like irregularity-absorbing resin layer 30.

[0059] Next, each step of the method for manufacturing an electronic device according to this embodiment will be described. 2 is a cross-sectional view schematically showing an example of a method for manufacturing an electronic device according to this embodiment. The method for manufacturing an electronic device according to this embodiment includes the following steps (A) and (B). (A) a preparation step of preparing a structure 60 including an electronic component 10 having a circuit-forming surface 10A, an adhesive laminate film 50 attached to the circuit-forming surface 10A of the electronic component 10, and a thermosetting protective film 70 attached to a surface of the electronic component 10 opposite to the circuit-forming surface 10A; (B) A thermosetting step of heating the structure 60 to thermally cure the thermosetting protective film 70 .

[0060] (Process (A)) First, a structure 60 is prepared, which includes an electronic component 10 having a circuit-forming surface 10A, an adhesive laminate film 50 attached to the circuit-forming surface 10A side of the electronic component 10, and a thermosetting protective film 70 attached to the surface 10C of the electronic component 10 opposite the circuit-forming surface 10A.

[0061] Such a structure 60 can be produced, for example, by carrying out a step (A1) of attaching an adhesive laminate film 50 to the circuit-forming surface 10A of the electronic component 10, and a step (A2) of attaching a thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10.

[0062] The method for attaching the adhesive laminate film 50 to the circuit-forming surface 10A of the electronic component 10 is not particularly limited, and can be any commonly known method. For example, the attachment may be performed manually, or may be performed using a device called an automatic attachment machine to which a roll of adhesive laminate film 50 is attached.

[0063] The method for attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 is not particularly limited, and the attachment can be performed by a generally known method. For example, the attachment may be performed manually, or by a device called an automatic attachment machine to which a roll-shaped thermosetting protective film 70 is attached.

[0064] Step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 is performed, for example, while heating the thermosetting protective film 70. The heating temperature in step (A2) is not particularly limited and is set appropriately depending on the type of thermosetting protective film 70, but is, for example, 50°C or higher and 90°C or lower, and preferably 60°C or higher and 80°C or lower.

[0065] The thermosetting protective film 70 is not particularly limited, and for example, a known thermosetting film for protecting the back surface of a semiconductor can be used. The thermosetting protective film 70 includes, for example, a thermosetting adhesive layer, and may further include a protective layer as needed. The adhesive layer is preferably formed from a thermosetting resin, and more preferably from a thermosetting resin and a thermoplastic resin. Examples of thermosetting resins include epoxy resins, phenolic resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. These thermosetting resins can be used alone or in combination. Among these, epoxy resins with low content of ionic impurities are preferred. Examples of thermoplastic resins include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin, phenoxy resin, acrylic resin, saturated polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyamide-imide resin, and fluororesin. These thermoplastic resins can be used alone or in combination. Among these, acrylic resins, which contain a low amount of ionic impurities, are preferred.

[0066] The adhesive layer may contain other additives as needed, such as fillers, flame retardants, silane coupling agents, ion trapping agents, extenders, antioxidants, antioxidants, surfactants, etc.

[0067] The protective layer is made of, for example, a heat-resistant resin, a metal, or the like. The heat-resistant resin constituting the protective layer is not particularly limited, but examples thereof include polyphenylene sulfide, polyimide, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, liquid crystal polymer, polytetrafluoroethylene, etc. Among these, polyimide, polyphenylene sulfide, polysulfone, polyetherimide, polyetherketone, polyetheretherketone, etc. are particularly preferred. The metal constituting the protective layer is not particularly limited, but examples thereof include aluminum, anodized aluminum, stainless steel, iron, titanium, tin, and copper.

[0068] A commercially available film may be used as the thermosetting protective film 70. An example of a commercially available film is chip backside protective tape (product name: "LC Tape" series) manufactured by Lintec Corporation.

[0069] The electronic component 10 is not particularly limited as long as it has a circuit formation surface 10A, but examples include a semiconductor wafer, a sapphire substrate, a lithium tantalate substrate, a mold wafer, a mold panel, a mold array package, a semiconductor substrate, etc. Examples of semiconductor substrates include silicon substrates, germanium substrates, germanium-arsenic substrates, gallium-phosphorus substrates, gallium-arsenic-aluminum substrates, and gallium-arsenic substrates.

[0070] Furthermore, electronic component 10 may be an electronic component for any purpose, including, for example, electronic components for logic (for example, for communication, high-frequency signal processing, etc.), memory, sensors, power supplies, etc. These may be used alone or in combination of two or more types.

[0071] The circuit formation surface 10A of the electronic component 10 has an uneven structure due to the presence of, for example, electrodes 10B. Furthermore, when the electronic device is mounted on the mounting surface, the electrode 10B is joined to an electrode formed on the mounting surface to form an electrical connection between the electronic device and the mounting surface (the mounting surface of a printed circuit board or the like). Examples of the electrode 10B include bump electrodes such as ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. That is, the electrode 10B is usually a convex electrode. These bump electrodes may be used alone or in combination of two or more types. The metal species constituting the bump electrode is not particularly limited, and examples thereof include silver, gold, copper, tin, lead, bismuth, and alloys thereof. These metal species may be used alone or in combination of two or more.

[0072] In the method for manufacturing an electronic device according to this embodiment, it is preferable to perform a curing step (A3) in which the irregularity-absorbing resin layer 30 in the adhesive laminate film 50 is thermally or ultraviolet-cured while the adhesive laminate film 50 is attached to the circuit-forming surface 10A of the electronic component 10. This improves the heat resistance of the adhesive laminate film 50. This can suppress warping of the electronic component 10 in the step (A2) in which a thermosetting protective film 70 is attached to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and in the thermal curing step (B) in which the thermosetting protective film 70 is thermally cured. Furthermore, in the step (A2) in which a thermosetting protective film 70 is attached to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and in the thermal curing step (B) in which the thermosetting protective film 70 is thermally cured, melting of the irregularity-absorbing resin layer 30 and resin extrusion can be suppressed. Although there are no particular limitations on the curing step (A3), it is preferable to perform it before the step (A2) of attaching the thermosetting protective film 70 to the surface 10C of the electronic component 10 opposite the circuit-forming surface 10A.

[0073] The method for thermally curing the irregularity-absorbing resin layer 30 is not particularly limited, but may be, for example, thermal crosslinking using a radical polymerization initiator. For the thermal crosslinking using a radical polymerization initiator, a known thermal radical polymerization initiator can be used.

[0074] Furthermore, by irradiating the irregularity-absorbing resin layer 30 with ultraviolet light, it is possible to crosslink and harden the irregularity-absorbing resin layer 30. For example, ultraviolet light is irradiated from the surface of the adhesive laminate film on the base layer 20 side. In any of the crosslinking methods, a crosslinking assistant may be added to the roughness-absorbent resin layer 30 to crosslink the roughness-absorbent resin layer 30 .

[0075] In the method for manufacturing an electronic device according to this embodiment, a backgrinding step (A4) may be performed in which, with the adhesive laminate film 50 attached to the circuit-forming surface 10A of the electronic component 10, the surface 10C of the electronic component 10 opposite the circuit-forming surface 10A is backgrinded. That is, the adhesive laminate film 50 according to this embodiment may be used as a backgrinding tape. Here, if the curing step (A3) is performed before the backgrinding step (A4), the adhesive strength of the adhesive laminate film 50 will decrease, and there is a concern that the adhesive laminate film 50 will peel off in the backgrinding step (A4). Therefore, it is preferable to perform the backgrinding step (A4) before the curing step (A3).

[0076] In the back grinding step (A4), while the electronic component 10 is attached to the adhesive laminated film 50, the surface 10C opposite to the circuit formation surface 10A of the electronic component 10 is back ground. Here, back grinding means thinning the electronic component 10 to a predetermined thickness without cracking or damaging the electronic component 10. The back grinding of the electronic component 10 can be performed by a known method, for example, by fixing the electronic component 10 to a chuck table or the like of a grinding machine and grinding the surface 10C of the electronic component 10 opposite the circuit-forming surface 10A.

[0077] The back grinding method is not particularly limited, but any known grinding method can be used, such as a through-feed method, an in-feed method, etc. In each case, grinding can be performed while cooling the electronic component 10 and the grindstone by pouring water over them.

[0078] (Process (B)) Next, the structure 60 is heated to thermally cure the thermosetting protective film 70 .

[0079] The heating temperature in step (B) of thermally curing the thermosetting protective film 70 is not particularly limited and is set appropriately depending on the type of thermosetting protective film 70, but is, for example, 120°C or higher and 170°C or lower, preferably 130°C or higher and 160°C or lower.

[0080] (Process (C)) Furthermore, in the method for manufacturing an electronic device according to this embodiment, step (B) may be followed by step (C) of peeling the electronic component 10 from the adhesive laminate film 50. By carrying out step (C), the electronic component 10 can be peeled from the adhesive laminate film 50. The peeling temperature is, for example, 20 to 100°C. The electronic component 10 and the adhesive laminate film 50 can be peeled off by a known method.

[0081] (Other processes) The method for manufacturing an electronic device according to this embodiment may include other steps in addition to those described above. As the other steps, known steps in the manufacture of electronic devices can be used.

[0082] For example, any process generally performed in the manufacturing process of electronic components, such as a metal film formation process, annealing process, dicing process, die bonding process, wire bonding process, flip chip connection process, cure heating test process, sealing process, reflow process, etc., may be further performed.

[0083] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can also be adopted.

[0084] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Example]

[0085] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to these.

[0086] <Base material layer> Base layer: polyethylene naphthalate film (product name: Teonex Q81, manufactured by Toyobo Film Solutions Co., Ltd., thickness: 50 μm, referred to as "PENQ81" in Table 1)

[0087] <Resin for forming the unevenness-absorbing resin layer> Resin 1: Ethylene-vinyl acetate copolymer (product name: Evaflex EV150, manufactured by Dow Mitsui Polychemicals, melting point: 61°C) Resin 2: Polymer P1 Synthesis of (meth)acrylic acid ester polymer P1 having thermally polymerizable double bonds 48 parts by weight of ethyl acrylate, 27 parts by weight of 2-ethylhexyl acrylate, 20 parts by weight of methyl acrylate, 5 parts by weight of glycidyl methacrylate, and 0.2 parts by weight (solids equivalent) of benzoyl peroxide as a polymerization initiator were mixed. The resulting solution was added dropwise to a nitrogen-purged flask containing 65 parts by weight of toluene and 50 parts by weight of ethyl acetate at 80°C over 5 hours with stirring, and the mixture was allowed to react for an additional 5 hours with stirring. After the reaction was complete, the resulting solution was cooled, and 25 parts by weight of xylene, 2.5 parts by weight of acrylic acid, and 1.5 parts by weight of tetradecylbenzylammonium chloride were added. The mixture was allowed to react for 10 hours at 80°C while blowing air into it, yielding a solution of (meth)acrylic acid ester-based polymer P1 having a thermally polymerizable double bond. The content of structural units derived from glycidyl methacrylate relative to all structural units constituting polymer P1 was 3.926 mol%.

[0088] <Resin for forming adhesive resin layer> The adhesive resin layer was formed using the following adhesive coating liquid. Adhesive polymer 77 parts by mass of n-butyl acrylate, 16 parts by mass of methyl methacrylate, 16 parts by mass of 2-hydroxyethyl acrylate, and 0.3 parts by mass of t-butylperoxy-2-ethylhexanoate as a polymerization initiator were reacted in 20 parts by mass of toluene and 80 parts by mass of ethyl acetate for 10 hours. After the reaction was completed, the solution was cooled, and 30 parts by mass of toluene, 7 parts by mass of methacryloyloxyethyl isocyanate (manufactured by Showa Denko K.K., product name: Karenz MOI), and 0.05 parts by mass of dibutyltin dilaurate were added thereto, and the mixture was reacted at 85°C for 12 hours while blowing in air to obtain a pressure-sensitive adhesive polymer solution. ·Adhesive coating liquid To 100 parts by mass of the above adhesive polymer (solid content), 8 parts by mass of benzyl dimethyl ketal (manufactured by BAFS, trade name: Irukagure 651) as a photoinitiator, 2.33 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name: Olestar P49-75S), and 6 parts by mass of ditrimethylolpropane tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name: AD-TMP) were added to obtain an adhesive coating solution.

[0089] Example 1 A composition was obtained by dry-blending Resin 1 (100 parts by mass) with 0.22 parts by mass of triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation, trade name: TAIC) as a crosslinking aid and 0.16 parts by mass of t-butylperoxy-2-ethylhexyl carbonate (manufactured by Arkema Yoshitomi Co., Ltd., trade name: Luperox TBEC) as a crosslinking agent. The composition was then melt-kneaded using a Labo Plastomill and molded to a thickness of 500 μm using a heat press machine to obtain a roughness-absorbing resin layer. Next, the substrate layer was attached to the irregularity-absorbing resin layer to obtain a laminated film.

[0090] Next, the adhesive coating liquid for the adhesive resin layer was applied to a silicone release-treated polyethylene terephthalate film and dried to form an adhesive resin layer with a thickness of 10 μm. The resulting adhesive resin layer was then bonded to the unevenness-absorbing resin layer side of the laminated film to obtain an adhesive resin film. The resulting adhesive resin film was evaluated as follows. The results are shown in Table 1.

[0091] <Evaluation> (1) Storage modulus G' b and evaluation of loss tangent tanδ The storage modulus was measured using a dynamic viscoelasticity measuring device (TA Instruments ARES viscoelasticity measuring device, using a 25 mm diameter parallel plate) at a frequency of 6.28 Hz in the temperature range of 0°C to 250°C. Specifically, the sample was set in the dynamic viscoelasticity measuring device at 100°C via the parallel plate jig, and the storage modulus was measured while the temperature was raised from 0°C to 250°C at a rate of 3°C / min. After the measurement, the temperature at which the storage modulus is minimum and its value (G') were determined in the range of 25°C or higher and lower than 250°C from the storage modulus-temperature curve obtained from 0°C to 250°C. bmin ), storage modulus G' at 30°C b30 , storage modulus G' at 250°C b250 The value of tanδ was also measured. The relationship between the storage modulus and temperature is shown in Figure 3. The relationship between the loss tangent and temperature is shown in Figure 4.

[0092] (2) Warpage evaluation of silicon test pieces A silicon wafer ground to a thickness of 75 μm was cut into individual pieces measuring 5 cm x 2.5 cm to prepare test pieces. The silicone release-treated polyethylene terephthalate film on the adhesive resin layer side of the adhesive resin film was peeled off, and the adhesive resin layer side of the adhesive resin film was attached to the test piece on a hot plate heated to 70 °C. The adhesive film was then cut to the size of the test piece to produce an adhesive resin film / silicon test piece laminate. The laminate was then placed with the silicone test piece side facing down on the release side of the silicone release-treated polyethylene terephthalate film in a heating oven and heated at 150 °C for 2 hours and 30 minutes. The removed laminate was then allowed to cool for 10 minutes, after which the silicone test piece side of the laminate sample was placed face down and the center of one short side (2.5 cm wide) of the laminate sample was pressed down with a finger from above. The height of the midpoint of the other short side of the sample that rose from the bottom was measured with a ruler, and this value was recorded as warpage. The warpage values ​​(unit: mm) are shown in the table.

[0093] (3) Warpage of 8-inch silicon wafers An 8-inch (200 mm) silicon wafer with a thickness of 100 μm was attached to an adhesive resin film. It was then placed in a heating oven and heated at 150°C for 2 hours. The laminate was then removed and left to cool for 10 minutes, after which the warpage of the silicon wafer was measured with a ruler. In the table, "-" means that no evaluation was made, and "x" means that the result showed significant warpage.

[0094] (4) Evaluation of seepage of the uneven absorbent resin layer After the warpage evaluation, the test pieces were visually inspected for exudation of the irregularity-absorbing resin layer from the edges. If exudation was detected, it was also checked whether the exuded resin layer was stuck to the polyethylene terephthalate film. The bleeding was evaluated according to the following criteria. ◎: No bleeding ○: There is bleeding, but it does not stick to the silicone release-treated polyethylene terephthalate film. ×: There is bleeding and the film is stuck to the silicone release-treated polyethylene terephthalate film.

[0095] (5) Appearance evaluation The appearance was evaluated based on the following criteria. ◎: No bubbles ○: There are bubbles, but the total area of ​​the bubbles is less than 30% of the total area of ​​the test piece ×: There are bubbles, and the total area of ​​the bubbles is 30% or more of the total area of ​​the test piece.

[0096] (Examples 2 and 3) Each adhesive resin film was produced in the same manner as in Example 1, except that the type of the irregularity-absorbing resin layer was changed to that shown in Table 1. Each evaluation was also carried out in the same manner as in Example 1. The obtained results are shown in Table 1.

[0097] (Comparative Examples 1 to 4) Each adhesive resin film was produced by changing the irregularity-absorbing resin layer to that shown in Table 1. Evaluations were also carried out in the same manner as in Example 1. The results are shown in Table 1. In Table 1, Olestar P49-75S is an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., trade name: Olestar P49-75S), and Perkadox 12 is an organic peroxide (manufactured by Nouryon Chemical Co., Ltd., trade name: Perkadox 12).

[0098] TIFF0007820360000001.tif81170

[0099] In Comparative Examples 1 and 2, warpage of the test piece and the silicon wafer could not be suppressed. In Comparative Examples 3 and 4, warpage of the test piece could be suppressed, but warpage of the silicon wafer could not be suppressed. Furthermore, in Comparative Examples 3 and 4, the tan δ value at 250°C was too high, so seepage occurred during heating. On the other hand, in Examples 1 and 2, warping of the test piece and silicon wafer was suppressed. Also, exudation of the irregularity-absorbing resin layer was suppressed. Furthermore, in Example 3, warping and exudation of the test piece were suppressed.

[0100] This application claims priority based on Japanese Patent Application No. 2021-071104, filed on April 20, 2021, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0101] 10. Electronic Components 10A circuit forming surface 10B electrode 10C Surface opposite to the circuit formation surface 20 Base material layer 30 Irregularity absorbent resin layer 40 Adhesive resin layer 50 Adhesive resin film (adhesive laminated film) 60 structure 70 Thermosetting protective film

Claims

1. An adhesive resin film used to protect a circuit-forming surface of an electronic component, the adhesive resin film comprising a base layer, an irregularity-absorbing resin layer, and an adhesive resin layer in this order, the irregularity-absorbing resin layer is a layer containing a cross-linkable resin, and the cross-linkable resin contains an ethylene-vinyl ester copolymer; the ethylene-vinyl ester copolymer comprises an ethylene-vinyl acetate copolymer, the resin constituting the base layer contains one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide; the adhesive constituting the adhesive resin layer comprises one or more adhesives selected from a (meth)acrylic adhesive, a silicone adhesive, a urethane adhesive, an olefin adhesive, and a styrene adhesive; The unevenness-absorbing resin layer further contains a crosslinking agent and a crosslinking assistant, The thickness of the base layer is 10 μm or more and 100 μm or less, The thickness of the irregularity-absorbing resin layer is 100 μm or more and 1000 μm or less, The thickness of the adhesive resin layer is 1 μm or more and 50 μm or less, The storage modulus G' of the irregularity-absorbing resin layer in the range of 25° C. or higher and lower than 250° C. ｂ The minimum value G' ｂｍｉｎ is 0.002 MPa or more and less than 0.006 MPa, and the storage modulus G' at 250°C is ｂ２５０ An adhesive resin film having a compressive strength of 0.007 MPa or more and 0.25 MPa or less.

2. The adhesive resin film according to claim 1, An adhesive resin film, wherein the loss tangent tanδ of the unevenness-absorbing resin layer at 250°C is 0.05 or more and 1.2 or less.

3. The adhesive resin film according to claim 1 or 2, Storage modulus G' of the uneven absorbent resin layer at 30°C ｂ３０ An adhesive resin film having a compressive strength of 0.1 MPa or more.

4. The adhesive resin film according to claim 1 or 2, Backgrind tape is an adhesive resin film.

5. The adhesive resin film according to claim 1 or 2, The crosslinking aid comprises one or more compounds selected from the group consisting of benzophenone compounds, divinyl aromatic compounds, cyanurate compounds, diallyl compounds, acrylate compounds, triallyl compounds, oxime compounds, and maleimide compounds.

6. The adhesive resin film according to claim 1 or 2, An adhesive resin film, wherein the resin constituting the base layer contains polyethylene naphthalate.

7. The adhesive resin film according to claim 1 or 2, excluding the adhesive laminate film used in a manufacturing method for an electronic device, which includes a step of forming an electromagnetic wave shielding layer on an electronic component attached to the adhesive laminate film.

8. a preparation step (A) of preparing a structure including an electronic component having a circuit formation surface, an adhesive laminate film attached to the circuit formation surface of the electronic component, and a thermosetting protective film attached to a surface of the electronic component opposite to the circuit formation surface; a heat curing step (B) of heat curing the thermosetting protective film by heating the structure; A method for manufacturing an electronic device comprising: A method for producing an electronic device, wherein the adhesive laminate film is the adhesive resin film according to claim 1 or 2.

9. 9. A method for manufacturing an electronic device according to claim 8, comprising: The step (A) a curing step of thermally curing or ultraviolet curing the irregularity-absorbing resin layer in the adhesive resin film in a state where the adhesive resin film is attached to the circuit-forming surface of the electronic component; attaching the thermosetting protective film to a surface of the electronic component opposite to the circuit formation surface; A method for manufacturing an electronic device, comprising:

10. 10. A method for manufacturing an electronic device according to claim 9, comprising: A method for manufacturing an electronic device, wherein the heating temperature in the step of attaching the thermosetting protective film to the surface of the electronic component opposite to the circuit formation surface is 50°C or higher and 90°C or lower.

11. 10. A method for manufacturing an electronic device according to claim 9, comprising: The method for manufacturing an electronic device includes a back-grinding step of back-grinding a surface of the electronic component opposite to the circuit-forming surface, with the adhesive resin film attached to the circuit-forming surface of the electronic component, before the curing step.

12. 9. A method for manufacturing an electronic device according to claim 8, comprising: The method for manufacturing an electronic device, wherein the heating temperature in step (B) is 120° C. or higher and 170° C. or lower.

13. 9. A method for manufacturing an electronic device according to claim 8, comprising: The method for manufacturing an electronic device, wherein the circuit formation surface of the electronic component includes bump electrodes.

14. 14. A method for manufacturing an electronic device according to claim 13, comprising: In the method for manufacturing an electronic device, when the height of the bump electrode is H [μm] and the thickness of the irregularity-absorbing resin layer is d [μm], H / d is 0.01 or more and 1 or less.

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