JP7464706B2 - Manufacturing method of electronic device - Google Patents

Description

The present invention relates to a method for manufacturing an adhesive laminate film and an electronic device.

In the manufacturing process of an electronic device (e.g., a semiconductor device), a process of attaching a thermosetting protective film to a non-circuit-forming surface (back surface) of an electronic component (e.g., a semiconductor wafer) may be performed in order to protect the non-circuit-forming surface (back surface) of the electronic component.
Examples of techniques related to such thermosetting protective films include those described in Patent Document 1 (JP 2017-1188 A).

Patent document 1 describes a protective film for semiconductors that has a protective layer made of a non-conductive inorganic material and an adhesive layer provided on one side of the protective layer.

JP 2017-1188 A

In recent years, electronic components have become thinner. According to the inventors' study, it has become clear that as electronic components become thinner, in conventional electronic device manufacturing methods, warping tends to occur more easily when a thermosetting protective film is attached to the non-circuit-forming surface of an electronic component and then the protective film is thermally cured, or after a back-grinding process. In particular, warping tends to occur more easily when the sealing resin and the semiconductor are integrated, such as in a wafer-level CSP, and the sealing resin is relatively thick. When electronic components warp, handling of the electronic components becomes difficult, and cracks occur in the electrodes.

The present invention has been made in consideration of the above circumstances, and provides an adhesive laminated film and a method for manufacturing an electronic device that can suppress warping of electronic components while suppressing contamination of the electronic components and peripheral devices.

The present inventors have conducted extensive research to achieve the above object. As a result, they have found that by using an adhesive laminate film having, in this order, a base layer, an unevenness-absorbing resin layer containing an ethylene copolymer having a melting point in a specific range and a crosslinking agent, and an adhesive resin layer, with the crosslinking agent content in a specific range, as a surface protection film for protecting the circuit formation surface of an electronic component, it is possible to suppress warping of the electronic component while suppressing contamination of the electronic component and peripheral devices associated with the adhesive film (particularly the seepage of the resin constituting the adhesive laminate film), and thus completed the present invention.

According to the present invention, there is provided a method for producing an adhesive laminate film and an electronic device as shown below.

[1]
An adhesive laminated film used to protect a circuit-forming surface of an electronic component, the adhesive laminate comprising a base layer, an irregularity-absorbing resin layer, and an adhesive resin layer in this order,
The unevenness-absorbing resin layer includes an ethylene copolymer having a melting point of 40° C. or more and 80° C. or less, and a crosslinking agent,
The content of the crosslinking agent in the unevenness-absorbing resin layer is from 0.06 parts by mass to 0.60 parts by mass relative to 100 parts by mass of the ethylene copolymer.
[2]
In the pressure-sensitive adhesive laminate film according to the above-mentioned [1],
The ethylene-based copolymer comprises at least one selected from the group consisting of ethylene/α-olefin copolymers and ethylene/vinyl ester copolymers.
[3]
In the pressure-sensitive adhesive laminate film according to the above-mentioned [2],
The adhesive laminated film, wherein the ethylene-vinyl ester copolymer comprises an ethylene-vinyl acetate copolymer.
[4]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [3],
The adhesive laminated film, wherein the crosslinking agent comprises at least one member selected from the group consisting of a photocrosslinking initiator and an organic peroxide.
[5]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [4],
An adhesive laminated film that is a backgrind tape.
[6]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [5],
The adhesive laminated film, wherein the unevenness-absorbing resin layer further contains a crosslinking assistant.
[7]
In the pressure-sensitive adhesive laminate film according to the above-mentioned [6],
The crosslinking auxiliary comprises one or more compounds selected from the group consisting of divinyl aromatic compounds, cyanurate compounds, diallyl compounds, acrylate compounds, triallyl compounds, oxime compounds and maleimide compounds.
[8]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [7],
The adhesive laminated film, wherein the resin constituting the base layer contains one or more resins selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide.
[9]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [7],
An adhesive laminate film, wherein the resin constituting the base layer contains polyethylene naphthalate.
[10]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [9],
The thickness of the unevenness-absorbing resin layer is from 10 μm to 1000 μm.
[11]
In the pressure-sensitive adhesive laminate film according to any one of the above [1] to [10],
An adhesive laminate film, wherein the adhesive constituting the adhesive resin layer comprises one or more adhesives selected from the group consisting of (meth)acrylic adhesives, silicone adhesives, urethane adhesives, olefin adhesives and styrene adhesives.
[12]
An electronic component having a circuit formation surface, an adhesive laminate film attached to the circuit formation surface side of the electronic component, and a thermosetting protective film attached to a surface of the electronic component opposite to the circuit formation surface;
A preparation step (A) of preparing a structure comprising:
a heat curing step (B) of heat curing the thermosetting protective film by heating the structure;
The method for producing an electronic device, comprising:
[13]
In the method for producing an electronic device according to the above [12],
The preparation step (A) is
a curing step of thermally curing or ultraviolet curing the unevenness-absorbing resin layer in the adhesive laminated film in a state where the adhesive laminated 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 the steps of:
[14]
In the method for producing an electronic device according to the above [13],
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.
[15]
In the method for producing an electronic device according to the above [13] or [14],
The preparation step (A) is a method for manufacturing an electronic device, the method including a back-grinding step of back-grinding a surface of the electronic component opposite to the circuit-forming surface, with the adhesive laminate film attached to the circuit-forming surface of the electronic component, prior to the curing step.
[16]
In the method for manufacturing an electronic device according to any one of the above [12] to [15],
The method for producing an electronic device, wherein the heating temperature in the thermal curing step (B) is 120° C. or higher and 170° C. or lower.
[17]
In the method for producing an electronic device according to any one of the above items [12] to [16],
The method for manufacturing an electronic device, wherein the circuit formation surface of the electronic component includes bump electrodes.
[18]
In the method for producing an electronic device according to the above [17],
A method for manufacturing an electronic device, wherein 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.

The present invention provides an adhesive laminate film and a method for manufacturing an electronic device that can suppress warping of electronic components while suppressing contamination of the electronic components and peripheral devices.

1 is a cross-sectional view showing a schematic example of an adhesive laminate film according to an embodiment of the present invention. 1A to 1C are cross-sectional views illustrating an example of a method for manufacturing an electronic device according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all drawings, similar components are given the same reference numerals and the description will be omitted as appropriate. The drawings are schematic and do not correspond to the actual dimensional ratios. Furthermore, the numerical range "A to B" represents A or more and B or less unless otherwise specified. Furthermore, in this embodiment, "(meth)acrylic" means acrylic, methacrylic, or both acrylic and methacrylic.

1. Adhesive Laminated Film Fig. 1 is a cross-sectional view that shows a schematic example of an adhesive laminated film 50 according to an embodiment of the present invention.
The adhesive laminate film 50 of this embodiment comprises a base layer 20, an unevenness-absorbing resin layer 30, and an adhesive resin layer 40, in this order, and is an adhesive laminate film 50 used to protect the circuit formation surface of an electronic component, wherein the unevenness-absorbing resin layer 30 contains an ethylene-based copolymer having a melting point of 40°C or more and 80°C or less, and a crosslinking agent, and the content of the crosslinking agent in the unevenness-absorbing resin layer 30 is 0.06 parts by mass or more and 0.60 parts by mass or less per 100 parts by mass of the ethylene-based copolymer.
The melting point of the ethylene copolymer is measured by differential scanning calorimetry (DSC).

As described above, according to the study by the present inventors, it has become clear that as the thickness of an electronic component becomes thinner, the electronic component tends to be more likely to warp when the thermosetting protective film is thermally cured after being attached to the non-circuit forming surface of the electronic component or after the back grinding process in the conventional manufacturing method for electronic devices. In particular, when the resin and the semiconductor are integrated as in a wafer level CSP and the thickness of the resin is relatively thick, the electronic component tends to be more likely to warp. When the electronic component warps, it becomes difficult to handle the electronic component or cracks occur in the electrodes.
The present inventors have conducted extensive research to achieve the above-mentioned object. As a result, they have found that by using an adhesive laminated film 50 having, in this order, a base layer 20, an ethylene copolymer having a melting point of 40° C. or more and 80° C. or less, and a crosslinking agent, and an unevenness-absorbing resin layer 30 and an adhesive resin layer 40, in which the content of the crosslinking agent is within the above-mentioned range, as a surface protection film for protecting the circuit-forming surface of an electronic component, it is possible to suppress the warping of the electronic component while suppressing the contamination of the electronic component and peripheral devices caused by the adhesive film (particularly the seepage of the resin constituting the adhesive laminated film).
As described above, the adhesive laminated film 50 according to this embodiment makes it possible to suppress warping of electronic components.

The adhesive laminated film 50 according to the present embodiment is used to protect the surface of electronic components and to fix electronic components in the manufacturing process of electronic devices, and more specifically, is preferably used as a backgrind 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 backgrind process), which is one of the manufacturing processes of electronic devices. Specifically, the adhesive laminated film 50 is attached to the circuit formation surface of the electronic component to protect it, and is used in the process of grinding the surface opposite to the circuit formation surface. When the circuit formation surface has a bump electrode, the adhesive laminated film 50 according to the present embodiment having the unevenness-absorbing resin layer 30 can be preferably applied.
In addition, the adhesive laminate film 50 according to this embodiment can also be used as an adhesive film used for protecting or holding an electronic component having an uneven surface (e.g., a semiconductor wafer, a sealing wafer, etc.) in a dicing process, a transfer process, etc.; an adhesive film for temporarily fixing an electronic component having an uneven surface (e.g., a semiconductor chip, a semiconductor package, etc.); or an adhesive film used in a heating process at 90°C or higher, such as dry polishing of an electronic component (e.g., a semiconductor wafer, etc.), attachment and curing of a back surface protection member of an electronic component (e.g., a semiconductor wafer, etc.), formation of an electromagnetic wave shielding film on an electronic component (e.g., a semiconductor package, etc.), and formation of a metal film on the back surface of an electronic component (e.g., a semiconductor wafer, etc.).

<Base layer>
The base layer 20 is a layer provided for the purpose of improving the properties of the adhesive laminated film 50, such as handleability, mechanical properties, and heat resistance.
The base layer 20 is not particularly limited, but may be, for example, a resin film.
The resin constituting the base layer 20 may be one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polyimide, and the like.
Among these, from the viewpoint of improving heat resistance even further, at least one selected from polyethylene naphthalate and polyimide is preferable, and polyethylene naphthalate is more preferable.

The substrate 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 film stretched uniaxially or biaxially.

From the viewpoint of obtaining good film characteristics, the thickness of the base layer 20 is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 200 μm or less, and further preferably 25 μm or more and 100 μm or less.
The substrate layer 20 may be subjected to a surface treatment in order to improve adhesion to other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coat treatment, etc. may be performed.

<Irregularity-absorbing resin layer>
The adhesive laminated film 50 according to this embodiment has an irregularity-absorbing resin layer 30 between a base layer 20 and an adhesive resin layer 40 .
The unevenness-absorbing resin layer 30 is a layer provided for the purpose of improving the conformability of the adhesive laminated film 50 to the circuit-forming surface 10A and improving the adhesion between the circuit-forming surface 10A and the adhesive laminated film 50. Furthermore, the unevenness-absorbing resin layer 30 is a layer provided for the purpose of increasing the heat resistance of the adhesive laminated film 50 by thermal curing or ultraviolet curing. This makes it possible to suppress warping of the electronic component in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the thermal curing step (B) of thermally curing the thermosetting protective film 70. Furthermore, in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the thermal curing step (B) of thermally curing the thermosetting protective film 70, the unevenness-absorbing resin layer 30 can be prevented from melting and causing resin to seep out.

The irregularity-absorbing resin layer 30 contains an ethylene-based copolymer.
As the ethylene-based copolymer according to the present embodiment, at least one selected from the group consisting of ethylene-α-olefin copolymers and ethylene-vinyl ester copolymers can be used.

The ethylene/α-olefin copolymer according to this embodiment is, for example, a copolymer obtained by copolymerizing ethylene with an α-olefin having 3 to 20 carbon atoms.
As the α-olefin, for example, α-olefins having 3 to 20 carbon atoms can be used alone or in combination of two or more. Among them, α-olefins having 10 or less carbon atoms are preferred, and α-olefins having 3 to 8 carbon atoms are particularly preferred. Specific 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 them, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene are preferred from the viewpoint of 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.

Examples of ethylene-α-olefin copolymers include TAFMER (registered trademark) manufactured by Mitsui Chemicals, Inc., ENGAGE (registered trademark) manufactured by Dow, EXACT (registered trademark) manufactured by ExxonMobil Corporation, and KERNEL (registered trademark) manufactured by Japan Polyethylene Corporation.

The density of the ethylene/α-olefin copolymer, measured in accordance with ASTM D1505, is preferably 850 to 900 kg/m ³ , more preferably 850 to 880 kg/m ³ , and even more preferably 850 to 870 kg/m ³ .
When the density is equal to or higher than the lower limit, handling problems such as blocking can be avoided. When the density is equal to or lower than the upper limit, an irregularity-absorbing resin layer 30 having excellent irregularity-absorbing properties can be obtained.
The melt flow rate (MFR) of the ethylene/α-olefin copolymer, measured in accordance with ASTM D1238 under conditions of 190° C. and a load of 2.16 kg, is preferably 0.1 to 50 g/10 min, more preferably 1 to 40 g/10 min, and even more preferably 3 to 35 g/10 min.
When the MFR is equal to or higher than the lower limit, the fluidity of the ethylene/α-olefin copolymer is improved, and the processability of the irregularity-absorbing resin layer 30 can be improved.
Furthermore, when the MFR is equal to or less than the upper limit, the unevenness-absorbing resin layer 30 can be obtained with a more uniform thickness, and exudation of the resin due to the unevenness-absorbing resin layer during the heating step can be suppressed.

The ethylene-vinyl ester copolymer according to this embodiment preferably contains one or more selected from, for example, ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, ethylene-vinyl butyrate copolymer, ethylene-vinyl stearate copolymer, etc., and more preferably contains ethylene-vinyl acetate copolymer.

The ethylene-vinyl acetate copolymer is a copolymer of ethylene and vinyl acetate, for example a random copolymer.
The content of the constituent unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is preferably 15% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 45% by mass or less, and even more preferably 25% by mass or more and 40% by mass or less. When the content of vinyl acetate is within this range, the balance of flexibility, heat resistance, transparency, and mechanical properties of the unevenness-absorbing resin layer 30 is more excellent. In addition, when forming the unevenness-absorbing resin layer 30 into a film, the film-forming property is also good.
The vinyl acetate content can be measured in accordance with JIS K7192:1999.

The ethylene-vinyl acetate copolymer is preferably a binary copolymer consisting of only ethylene and vinyl acetate, but may contain, in addition to ethylene and vinyl acetate, one or more copolymerization components selected from, for example, vinyl ester monomers such as vinyl formate, vinyl glycolate, vinyl propionate, and vinyl benzoate; acrylic monomers such as acrylic acid, methacrylic acid, ethacrylic acid, or salts or alkyl esters thereof; etc. When copolymerization components other than the above ethylene and vinyl acetate are contained, it is preferable that the amount of the copolymerization components other than the above ethylene and vinyl acetate in the ethylene-vinyl acetate copolymer is 0.5% by mass or more and 5% by mass or less.

The melt flow rate (MFR) of the ethylene-vinyl ester copolymer, measured in accordance with JIS K7210:1999 under conditions of 190°C and a load of 2.16 kg, is preferably 0.1 to 50 g/10 min, more preferably 1 to 40 g/10 min, and even more preferably 3 to 35 g/10 min.
When the MFR is equal to or higher than the lower limit, the fluidity of the ethylene-vinyl ester copolymer is improved, and the moldability of the irregularity-absorbing resin layer 30 can be improved.
Furthermore, when the MFR is below the above upper limit, the molecular weight becomes high, making it difficult for adhesion to the roll surface of a chill roll or the like to occur, so that an unevenness-absorbing resin layer 30 of a more uniform thickness can be obtained, and the seepage of resin due to the unevenness-absorbing resin layer during the heating process can be suppressed.

The unevenness-absorbing resin layer 30 can be obtained, for example, by dry blending or melt-kneading each component, followed by extrusion molding. In addition, an antioxidant can be added as necessary.

The total content of the ethylene-based copolymer and crosslinking agent contained in the unevenness-absorbing resin layer 30 is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more, when the entire unevenness-absorbing resin layer 30 is taken as 100% by mass.

The melting point of the ethylene copolymer is 40° C. or higher, preferably 45° C. or higher, more preferably 50° C. or higher, and even more preferably 54° C. or higher.
When the melting point of the ethylene-based copolymer is equal to or higher than the lower limit, it is possible to suppress deformation during transportation and storage of the adhesive laminated film 50. Furthermore, when the melting point of the ethylene-based copolymer is equal to or higher than the lower limit, it is possible to suppress deformation of the adhesive laminated film 50 during the backgrinding process, and it is possible to further improve backgrinding of electronic components. Furthermore, when the melting point of the ethylene-based copolymer is equal to or higher than the lower limit, it is possible to increase the processing temperature of the unevenness-absorbing resin layer 30.

The melting point of the ethylene copolymer is 80° C. or lower, preferably 75° C. or lower, more preferably 70° C. or lower, and further preferably 65° C. or lower.
When the melting point of the ethylene-based copolymer is equal to or lower than the upper limit, the temperature can be lowered when attaching the adhesive laminate film 50 to an electronic component. Furthermore, when the melting point of the ethylene-based copolymer is equal to or lower than the upper limit, the compatibility of the additives with the ethylene-based copolymer can be improved, and as a result, bleeding out of the additives contained in the irregularity-absorbing resin layer 30 can be suppressed. Furthermore, when the melting point of the ethylene-based copolymer is equal to or lower than the upper limit, the handleability of the adhesive laminate film 50 and the stress relaxation property of the adhesive laminate film 50 can be further improved when the thickness of the adhesive laminate film 50 is increased.

When two or more ethylene copolymers are included, two or more melting points may be observed, but it is sufficient that at least one of the melting points is within the above range. It is preferable that the two or more melting points are all within the above range.

In addition, the unevenness-absorbing resin layer 30 contains a crosslinking agent. By containing a crosslinking agent in the unevenness-absorbing resin layer 30, the unevenness-absorbing resin layer 30 can be effectively heat-cured or UV-cured before the step (B), and the heat resistance of the unevenness-absorbing resin layer 30 can be improved. This makes it possible to further suppress warping of the electronic component in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the heat-curing step (B) of heat-curing the thermosetting protective film 70. Furthermore, in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the heat-curing step (B) of heat-curing the thermosetting protective film 70, the unevenness-absorbing resin layer 30 can be further suppressed from melting and exuding the resin in the heat-curing step (B).
The crosslinking agent according to the present embodiment is not particularly limited, but for example, at least one selected from the group consisting of a photocrosslinking initiator and an organic peroxide can be used.
From the viewpoint of suppressing warping, the content of the crosslinking agent in the unevenness-absorbing resin layer 30 is 0.60 parts by mass or less, preferably 0.55 parts by mass or less, and more preferably 0.50 parts by mass or less, per 100 parts by mass of the ethylene-based copolymer.
In addition, from the viewpoint of preventing the resin from bleeding out when heated, the content of the crosslinking agent in the unevenness-absorbing resin layer 30 is 0.06 parts by mass or more, preferably 0.07 parts by mass or more, and more preferably 0.08 parts by mass or more, per 100 parts by mass of the ethylene-based copolymer.

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 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-butylperoxyacetate, t-butylperoxyisononanoate, t-butylperoxybenzoate, 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-butylperoxybenzoate, di-t-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and acetylacetone peroxide can be used.

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.

As the photocrosslinking initiator, 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 can be used. Among them, benzophenone, benzophenone derivatives, benzoin, benzoin derivatives, α-hydroxyalkylphenones, oxime esters, and anthraquinone derivatives are preferred in terms of better crosslinkability, benzophenone, benzophenone derivatives, and anthraquinone derivatives are more preferred, and benzophenone and benzophenone derivatives are most preferred because of 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 derivatives include 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, and 1-chloroanthraquinone.

In addition, from the viewpoint of further improving heat resistance, the irregularity-absorbing resin layer 30 preferably further contains a cross-linking assistant.
As the crosslinking aid, for example, one or more compounds selected from the group consisting of a divinyl aromatic compound, a cyanurate compound, a diallyl compound, an acrylate compound, a triallyl compound, an oxime compound, and a maleimide compound can be used.
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, and particularly preferably 1.0 part by mass or less, per 100 parts by mass of the ethylene-based copolymer.
In addition, 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, and even more preferably 0.10 parts by mass or more, per 100 parts by mass of the ethylene-based copolymer.

The divinyl aromatic compounds include, for example, divinylbenzene, di-i-propenylbenzene, and the like.
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-quinone dioxime, pp'-dibenzoylquinone dioxime, and the like.
An example of the maleimide compound is m-phenylenedimaleimide.
As the crosslinking aid, a compound having three or more functional crosslinkable unsaturated bonds such as vinyl groups in one molecule is preferred, and among them, triallyl cyanurate, triallyl isocyanurate, trimethylolpropane tri(meth)acrylate, and ditrimethylolpropane tetra(meth)acrylate are preferred in terms of good crosslinkability, and triallyl cyanurate and triallyl isocyanurate are particularly preferred.

The thickness of the unevenness-absorbing resin layer 30 is not particularly limited as long as it is a thickness that can embed the unevenness of the circuit formation surface 10A of the electronic component 10, 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, and particularly preferably 50 μm or more and 700 μm or less.

When the height of the bump electrode present on the circuit formation surface 10A of the electronic component 10 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 laminated film 50 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.

<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 10A of the electronic component 10 when the adhesive laminate film 50 is attached to the circuit-forming surface 10A of the electronic component 10.

Examples of adhesives constituting the adhesive resin layer 40 include (meth)acrylic adhesives, silicone adhesives, urethane adhesives, olefin adhesives, and styrene adhesives. Among these, (meth)acrylic adhesives that use a (meth)acrylic polymer as the base polymer are preferred because they allow easy adjustment of the adhesive strength.

A radiation crosslinking adhesive, the adhesive strength of which is reduced by radiation, may also be used as the adhesive constituting the adhesive resin layer 40. The adhesive resin layer 40 made of a radiation crosslinking adhesive is crosslinked by irradiation with radiation and has a significantly reduced adhesive strength, so that the electronic component 10 can be easily peeled off from the adhesive resin layer 40 in step (C) of peeling the electronic component 10 from the adhesive laminate film 50, 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.

Examples of the (meth)acrylic polymer contained in the (meth)acrylic pressure-sensitive adhesive include a homopolymer of a (meth)acrylic acid ester compound, a copolymer of a (meth)acrylic acid ester compound and a comonomer, etc. 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, glycidyl (meth)acrylate, etc. 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.

The radiation-crosslinkable 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.

Examples of the crosslinkable compound 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, and tris(2-methacryloxyethyl)isocyanurate.
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.

The content of the crosslinkable compound is preferably 1 to 900 parts by mass, more preferably 2 to 100 parts by mass, and even more preferably 5 to 50 parts by mass, per 100 parts by mass of the (meth)acrylic polymer. When the content of the crosslinkable compound is within the above range, it becomes easier to adjust the adhesive strength compared to when the content is less than the above range, and the storage stability is less likely to decrease due to excessive sensitivity to heat and light compared to when the content is more than the above range.

The photopolymerization initiator may be any compound that cleaves and generates radicals when irradiated with radiation, and examples of such compounds 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.

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 when heated. Examples of the thermal polymerization initiator include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxy esters, and peroxydicarbonates.

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); and isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, and polyisocyanate.
From the viewpoint of improving the balance between the heat resistance and adhesive strength of the adhesive resin layer 40, the content of the crosslinking agent is preferably 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the (meth)acrylic polymer.

The thickness of the adhesive resin layer 40 is not particularly limited, but is preferably, for example, 1 μm or more and 100 μm or less, and more preferably 3 μm or more and 50 μm or less.

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 coated by a conventional coating method such as a roll coater method, a reverse roll coater method, a gravure roll method, a bar coat method, a comma coater method, a die coater method, etc. There is no particular restriction on the drying conditions of the coated adhesive, but it is generally preferable to dry the coated adhesive at a temperature range of 80 to 200°C for 10 seconds to 10 minutes. More preferably, the coated adhesive is dried at 80 to 170°C for 15 seconds to 5 minutes. In order 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 about 5 to 300 hours after drying is completed.

The adhesive laminate film 50 of this embodiment must have a light transmittance such that when the unevenness-absorbing resin layer 30 is cured by ultraviolet light or the adhesive resin layer 40 is crosslinked by ultraviolet light, the curing or crosslinking does not interfere with the objectives of the present invention.

The overall thickness of the adhesive laminate film 50 in this embodiment is preferably 25 μm or more and 1100 μm or less, more preferably 100 μm or more and 900 μm or less, and even more preferably 200 μm or more and 800 μm or less, in terms of the balance between mechanical properties and handleability.

The adhesive laminate film 50 according to this embodiment may have an adhesive layer (not shown) between each layer. This adhesive layer can improve the adhesion between each layer.

Next, an example of a method for producing the adhesive laminated film 50 according to this embodiment will be described.
First, the 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 laminated film 50.
The base material layer 20 and the irregularity-absorbing resin layer 30 may be formed by co-extrusion molding, or the base material layer 20 in the form of a film and the irregularity-absorbing resin layer 30 in the form of a film may be laminated together.

2. Method for Manufacturing Electronic Device Next, each step of the method for manufacturing an electronic device according to this embodiment will be described.
2A to 2C are cross-sectional views that diagrammatically show an example of a method for manufacturing an electronic device according to an embodiment of the present invention.
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 formation surface 10A, an adhesive laminate film 50 attached to the circuit formation surface 10A side of the electronic component 10, and a thermosetting protective film 70 attached to the surface 10C opposite the circuit formation surface 10A of the electronic component 10. (B) A heat curing step of heat curing the thermosetting protective film 70 by heating the structure 60. Here, the circuit formation surface 10A of the electronic component 10 and the adhesive resin layer 40 are in contact.

(Step (A))
First, a structure 60 is prepared, which includes an electronic component 10 having a circuit formation surface 10A, an adhesive laminate film 50 attached to the circuit formation 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 formation surface 10A.

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.

The method for attaching the adhesive laminate film 50 to the circuit formation surface 10A of the electronic component 10 is not particularly limited, and the adhesive laminate film 50 can be peeled off by a generally known method. For example, the peeling may be done manually or by a device called an automatic attachment machine to which a roll of the adhesive laminate film 50 is attached.

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

The step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit formation surface 10A of the electronic component 10 is performed, for example, while heating the thermosetting protective film 70. The heating temperature in the step (A2) is not particularly limited since it is appropriately set 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.

There are no particular limitations on the thermosetting protective film 70, 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 necessary.
The adhesive layer is preferably formed from a thermosetting resin, and more preferably from a thermosetting resin and a thermoplastic resin.
Examples of the thermosetting resin include epoxy resin, phenol resin, amino resin, unsaturated polyester resin, polyurethane resin, silicone resin, thermosetting polyimide resin, etc. These thermosetting resins can be used alone or in combination. Among these, epoxy resins with a 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, polyamideimide resin, fluororesin, etc. These thermoplastic resins can be used alone or in combination. Among these, acrylic resins with a low content of ionic impurities, etc. are preferred.

The adhesive layer may contain other additives as necessary. Examples of other additives include fillers, flame retardants, silane coupling agents, ion trapping agents, extenders, antioxidants, antioxidants, surfactants, etc.

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, 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.

A commercially available film may be used as the thermosetting protective film 70. Examples of commercially available films include chip back surface protective tape manufactured by Lintec Corporation (product name: "LC Tape" series).

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

The electronic component 10 may be an electronic component for any purpose, such as an electronic component for logic (e.g., 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.

The circuit formation surface 10A of the electronic component 10 has an uneven structure due to, for example, the presence of electrodes 10B.
Furthermore, when the electronic device is mounted on the mounting surface, 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, etc.).
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.

In the manufacturing method of the electronic device according to the present embodiment, it is preferable to perform a curing step (A3) in which the unevenness-absorbing resin layer 30 in the adhesive laminated film 50 is thermally cured or ultraviolet-cured while the adhesive laminated film 50 is attached to the circuit-forming surface 10A of the electronic component 10. This can improve the heat resistance of the adhesive laminated film 50. In this way, warping of the electronic component 10 can be suppressed in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the thermal curing step (B) of thermally curing the thermosetting protective film 70. Furthermore, in the step (A2) of attaching the thermosetting protective film 70 to the surface 10C opposite the circuit-forming surface 10A of the electronic component 10 and the thermal curing step (B) of thermally curing the thermosetting protective film 70, the unevenness-absorbing resin layer 30 can be prevented from melting and causing resin to seep out. The curing step (A3) is not particularly limited, but is preferably performed before the step (A2) of attaching the thermosetting protective film 70 to the surface 10C of the electronic component 10 opposite the circuit formation surface 10A.

The method for thermally curing the irregularity-absorbing resin layer 30 is not particularly limited as long as it is a method capable of thermally curing an ethylene copolymer, and examples of the method include thermal crosslinking using a radical polymerization initiator.
For thermal crosslinking with a radical polymerization initiator, a radical polymerization initiator used for crosslinking of an ethylene copolymer can be used. As the radical polymerization initiator, a known thermal radical polymerization initiator can be used.

Moreover, by irradiating the unevenness-absorbing resin layer 30 with ultraviolet light, the unevenness-absorbing resin layer 30 can be crosslinked and cured.
For example, the ultraviolet light is applied to the surface of the adhesive laminate film 50 on the side of the base layer 20 .
In any of the crosslinking methods, a crosslinking assistant may be blended into the irregularity-absorbing resin layer 30 to crosslink the irregularity-absorbing resin layer 30 .

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

In the back grinding step (A4), while the electronic component 10 is attached to the adhesive laminated film 50, the surface 10C opposite 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, a method in which the electronic component 10 is fixed to a chuck table of a grinding machine or the like, and a surface 10C of the electronic component 10 opposite to the circuit formation surface 10A is ground.

The back grinding method is not particularly limited, but any known grinding method such as the through-feed method or the in-feed method can be used. In each case, grinding can be performed while spraying water on the electronic component 10 and the grindstone to cool them.

(Step (B))
Next, the structure 60 is heated to thermally cure the thermosetting protective film 70 .

The heating temperature in step (B) of thermally curing the thermosetting protective film 70 is not particularly limited as it 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.

(Step (C))
Furthermore, in the method for manufacturing an electronic device according to the present embodiment, after step (B), step (C) of peeling the electronic component 10 from the adhesive laminate film 50 may be further performed. By performing this 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 laminated film 50 can be peeled off by a known method.

(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, steps known in the art for manufacturing electronic devices can be used.

For example, any process commonly 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.

The above describes embodiments of the present invention, but these are merely examples of the present invention and various configurations other than those described above can also be adopted.

The present invention is not limited to the above-described embodiments, and modifications, improvements, etc. that are within the scope of achieving the object of the present invention are included in the present invention.

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited thereto.
Details regarding the preparation of the adhesive film are as follows.

<Base layer>
Base layer 1: polyethylene naphthalate film (product name: Teonex Q81, manufactured by Toyobo Film Solutions Co., Ltd., thickness: 50 μm)
Base layer 2: Polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name: E7180, thickness: 50 μm)

<Resin for forming 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: Ethylene-propylene copolymer (product name: Tafmer A35070S, manufactured by Mitsui Chemicals, melting point: 55°C)
Resin 3: Ethylene-propylene copolymer (product name: TAFMER A4070, manufactured by Mitsui Chemicals, Inc., melting point: 55° C.)

<Adhesive polymer (acrylic resin)>
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 with 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 Solution for Adhesive Resin Layer>
To 100 parts by mass of the adhesive polymer (solid content), 8 parts by mass of benzyl dimethyl ketal (manufactured by BASF, product name: Irgacure 651) as a photoinitiator, 2.33 parts by mass of an isocyanate-based crosslinking agent (manufactured by Mitsui Chemicals, Inc., product name: Olestar P49-75S), and 6 parts by mass of ditrimethylolpropane tetraacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name: AD-TMP) were added, to obtain an adhesive coating liquid.

[Example 1]
A composition was obtained by dry blending resin 1 (100 parts by mass), 0.44 parts by mass of crosslinking aid triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation, product name: Taiku), and 0.32 parts by mass of crosslinking agent t-butylperoxy-2-ethylhexyl carbonate (manufactured by Arkema Yoshitomi, product name: Luperox TBEC). 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 an irregularity-absorbing resin layer. Next, the substrate layer 1 was bonded to the irregularity-absorbing resin layer to produce a laminated film.

Next, the adhesive coating liquid for the adhesive resin layer was applied to a polyethylene terephthalate film (38 μm) that had been subjected to a silicone release treatment, and dried to form an adhesive resin layer having a thickness of 20 μm. The resulting adhesive resin layer was then bonded to the unevenness-absorbing resin layer side of the laminated film described above to obtain an adhesive film. The following evaluations were performed on the resulting adhesive film. The results are shown in Table 1.

<Evaluation>
(1) Melting point of ethylene-based copolymer The melting point of the ethylene-based copolymer was measured by differential scanning calorimetry (DSC) using a differential scanning calorimeter (manufactured by SII, product name: X-DSC7000). Approximately 10 mg of the sample was placed in an aluminum pan, and the temperature was raised from 30°C to 230°C at 10°C/min (1st heating), and then held for 5 minutes. Next, the sample was cooled to -100°C at 10°C/min, held for 5 minutes, and then heated again to 230°C at 10°C/min (2nd heating). In a graph during the 2nd heating with temperature on the horizontal axis and DSC on the vertical axis, the melting point was determined from the endothermic peak.

(2) Evaluation of warpage of silicon test piece A test piece was prepared by cutting a silicon wafer ground to 75 um into individual pieces of 5 cm x 2.5 cm. The silicone release-treated polyethylene terephthalate film on the adhesive resin layer side of the adhesive film was peeled off and attached on a hot plate heated to 70 ° C., and then the adhesive film was cut along the size of the test piece to prepare an adhesive film / silicon test piece laminate. Thereafter, the laminate was placed on the release surface of the silicone release-treated polyethylene terephthalate with the silicone test piece side facing down, and placed in a heating oven, and heated at 150 ° C. for 2 hours and 30 minutes. Thereafter, the removed laminate was left to stand and cooled for 10 minutes, and then the silicon test piece side of the laminate sample was placed down, and the center of one short side (2.5 cm wide) of the laminate sample was pressed from above with a finger, and the height from the bottom surface of the midpoint of the other sample short side that was lifted at that time was measured with a ruler, and the value was taken as the warpage.
The warpage was evaluated according to the following criteria.
◎:≦2mm
◯: 2mm < warpage < 4mm
×: ≧4 mm

(3) Exudation evaluation of the irregularity-absorbing resin layer After the warpage evaluation, it was visually confirmed whether the irregularity-absorbing resin layer had exuded from the end of the test piece. If the exuded resin layer had exuded, it was confirmed whether the exuded resin layer had stuck to the polyethylene terephthalate film.
The bleeding was evaluated according to the following criteria.
◎: No bleeding ○: Bleeding occurred, but the material did not stick to the silicone release-treated polyethylene terephthalate ×: Bleeding occurred, and the material stuck to the silicone release-treated polyethylene terephthalate

[Examples 2 to 4 and Comparative Examples 1 and 2]
Each pressure-sensitive adhesive film was produced in the same manner as in Example 1, except that the types of the base layer and the unevenness-absorbing resin layer were changed to those shown in Table 1. In addition, each evaluation was performed in the same manner as in Example 1. The obtained results are shown in Table 1.

[Example 5]
Each adhesive film was produced in the same manner as in Example 1, except that the types of the base layer and the unevenness-absorbing resin layer were changed to those shown in Table 1. In addition, in the warpage evaluation, each evaluation was performed in the same manner as in Example 1, except that UV irradiation was performed from the adhesive film side at room temperature with an irradiation intensity of 100 mW/ ^cm2 and 3240 mJ/ ^cm2 using a high-pressure mercury lamp before the adhesive film/silicon test piece laminate was placed in a heating oven. The obtained results are shown in Table 1. Here, 4-methylbenzophenone (manufactured by SHUANG-BANG INDUSTRIAL, product name: SB-PI712) was used as the photoinitiator.

This application claims priority based on Japanese Patent Application No. 2020-089610, filed on May 22, 2020, the disclosure of which is incorporated herein in its entirety.

10 Electronic component 10A Circuit-forming surface 10B Electrode 10C Surface opposite to the circuit-forming surface 20 Base layer 30 Irregularity-absorbing resin layer 40 Adhesive resin layer 50 Adhesive laminated film 60 Structure 70 Thermosetting protective film

Claims (17)

an electronic component having a circuit formation surface, an adhesive laminate film attached to the circuit formation surface side of the electronic component, and a thermosetting protective film attached to a surface of the electronic component opposite to the circuit formation surface;
A preparation step (A) of preparing a structure comprising:
a heat curing step (B) of heat curing the thermosetting protective film by heating the structure;
A method for manufacturing an electronic device comprising:
The adhesive laminated film is provided with a base layer, an irregularity-absorbing resin layer, and an adhesive resin layer in this order, and is used to protect a circuit-forming surface of an electronic component,
The unevenness-absorbing resin layer includes an ethylene copolymer having a melting point of 40° C. or more and 80° C. or less, and a crosslinking agent,
A method for producing an electronic device, wherein the content of the crosslinking agent in the unevenness-absorbing resin layer is 0.06 parts by mass or more and 0.60 parts by mass or less based on 100 parts by mass of the ethylene-based copolymer. 2. The method of claim 1, further comprising the steps of:
The method for producing an electronic device includes the step of: (a) providing an ethylene-based copolymer that contains at least one selected from the group consisting of ethylene-α-olefin copolymers and ethylene-vinyl ester copolymers; 3. The method of claim 2, further comprising the steps of:
The method of manufacturing an electronic device, wherein the ethylene-vinyl ester copolymer comprises an ethylene-vinyl acetate copolymer. 4. The method for manufacturing an electronic device according to claim 1, further comprising the steps of:
The method for producing an electronic device, wherein the crosslinking agent comprises at least one selected from the group consisting of a photocrosslinking initiator and an organic peroxide. 5. The method for manufacturing an electronic device according to claim 1, further comprising the steps of:
The method for manufacturing an electronic device, wherein the adhesive laminated film is a backgrind tape. 6. The method for manufacturing an electronic device according to claim 1 ,
The method for producing an electronic device, wherein the unevenness-absorbing resin layer further contains a crosslinking assistant. 7. The method of claim 6, further comprising the steps of:
The method for producing an electronic device, wherein the crosslinking auxiliary comprises one or more compounds selected from the group consisting of a divinyl aromatic compound, a cyanurate compound, a diallyl compound, an acrylate compound, a triallyl compound, an oxime compound, and a maleimide compound . 8. The method for manufacturing an electronic device according to claim 1 , further comprising the steps of:
The method for producing an electronic device, wherein the resin constituting the base layer contains one or more kinds selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide. 8. The method for manufacturing an electronic device according to claim 1 , further comprising the steps of:
The method for producing an electronic device, wherein the resin constituting the base layer contains polyethylene naphthalate. 10. The method of claim 1 , further comprising the steps of:
The method for producing an electronic device, wherein the unevenness-absorbing resin layer has a thickness of 10 μm or more and 1000 μm or less. 11. The method of claim 1 , further comprising the steps of:
The method for producing an electronic device, wherein 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. 12. The method of claim 1, further comprising the steps of:
The preparation step (A) includes:
a curing step of thermally curing or ultraviolet curing the unevenness-absorbing resin layer in the adhesive laminated film in a state where the adhesive laminated 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 the steps of: 13. The method of claim 12 , further comprising the steps of:
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. 14. The method for manufacturing an electronic device according to claim 12 ,
The preparation step (A) is a method for manufacturing an electronic device, comprising a back-grinding step of back-grinding a surface of the electronic component opposite to the circuit-forming surface, with the adhesive laminate film attached to the circuit-forming surface of the electronic component, prior to the curing step. 15. The method of claim 1 , further comprising the steps of:
The method for producing an electronic device, wherein the heating temperature in the thermal curing step (B) is 120° C. or higher and 170° C. or lower. 16. The method of claim 1 , further comprising the steps of:
The method for manufacturing an electronic device, wherein the circuit formation surface of the electronic component includes bump electrodes. 17. The method of claim 16 , further comprising the steps of:
A method for manufacturing an electronic device, wherein 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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