JP7049796B2 - Adhesive film - Google Patents

Description

The present invention relates to an adhesive film.

In the process of grinding electronic components in the manufacturing process of electronic devices, an adhesive film is attached to the circuit forming surface of the electronic components in order to fix the electronic components and prevent damage to the electronic components. Be done.
As such an adhesive film, a film in which an adhesive resin layer is laminated on a base film is generally used.
On the other hand, for electronic components with large irregularities on the circuit forming surface, an adhesive resin layer is provided between the base film and the adhesive resin layer in order to impart unevenness absorption to the adhesive film. Film is being considered.

Examples of the technique relating to the adhesive film having such unevenness absorbing property include those described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2014-11273).

Patent Document 1 has at least one low elastic modulus layer on one surface of a high elastic modulus film, and has a radiation-curable pressure-sensitive adhesive layer on the low elastic modulus layer, and the high elastic modulus. The Young modulus of the material film is 5.0 × 10 ⁸ Pa to 1.1 × 10 ¹⁰ Pa, and the storage elastic modulus G'(25 ° C.) of the low elastic modulus layer at 25 ° C. is 2.5 × 10 ⁵ . The storage elastic modulus G'(60 ° C.) at 60 ° C. is 0.2 × 10 ⁵ Pa to 1.5 × 10 ⁵ Pa at Pa to 4.0 × 10 ⁵ Pa, and the ratio G'(60 ° C.) ° C.) / G'(25 ° C.) is 0.5 or less, and the loss positive tan δ (25 ° C.) of the low elastic modulus layer at 25 ° C. is 0.08 to 0.15, and the loss at 60 ° C. The ratio tan δ (60 ° C.) / tan δ (25 ° C.) to the normal contact tan δ (60 ° C.) is 4.0 or more, and the thickness of the radiation-curable pressure-sensitive adhesive layer is 5 to 100 μm, and the elastic modulus is low. Described is an adhesive tape for processing a semiconductor wafer, characterized in that the ratio of the thickness of the rate layer to the radiation-curable pressure-sensitive adhesive layer and the thickness of the radiation-curable pressure-sensitive adhesive layer / the thickness of the low elastic modulus layer are 1/2 or less. ing.

Japanese Unexamined Patent Publication No. 2014-11273

According to the study by the present inventors, the adhesive film including the base material layer, the unevenness-absorbing resin layer, and the adhesive resin layer in this order has the ability to absorb the unevenness of the circuit forming surface of the electronic component. Although it is excellent, it has become clear that burrs are likely to occur when cutting to the size of electronic components. If the adhesive film has burrs, the electronic component may be cracked or scratched when the electronic component is ground or when the adhesive film is peeled off from the electronic component.

The present invention has been made in view of the above circumstances, and provides an adhesive film having an excellent balance between unevenness absorption and cutability.

The present inventors have made extensive studies to achieve the above-mentioned problems. As a result, in the adhesive film provided with the base material layer, the unevenness-absorbing resin layer, and the adhesive resin layer in this order, the unevenness-absorbing resin layer that can be torn when a specific tear test is performed is obtained. The present invention has been completed by finding that it is possible to improve the cuttability while maintaining good unevenness absorption by using it.

According to the present invention, the adhesive film shown below is provided.

[1]
An adhesive film used to protect the circuit forming surface of electronic components or to fix electronic components.
A base material layer, an uneven absorption resin layer, and an adhesive resin layer are provided in this order.
When the following tear test is performed, the uneven absorbent resin layer can be torn because the tear progresses from the cut .
The uneven absorbent resin layer is
It contains an ethylene / α-olefin copolymer (A) and at least one polymer (B) selected from an ethylene / polar monomer copolymer (B1) and a propylene-based polymer (B2).
Adhesive film that is a back grind tape .
(Tear test)
A press sheet having a thickness of 1.0 ± 0.1 mm × a length of 150 mm × a width of 50 mm produced by using the uneven absorbent resin layer is produced. Next, a cut having a length of 75 mm is made in the vertical direction of the press sheet. Next, using a tensile tester, the press sheet is torn in the direction of 180 ° starting from the cut in the press sheet under the conditions of 23 ° C. and a tensile speed of 200 mm / min.
[2]
In the adhesive film according to the above [1],
An adhesive film having a tear strength of 0.5 N / mm or more and 10 N / mm or less as measured by the tear test.
[3 ]
In the adhesive film according to the above [1] or [2] ,
An adhesive film in which the ethylene / polar monomer copolymer (B1) contains an ethylene / vinyl acetate copolymer.
[ 4 ]
In the adhesive film according to any one of the above [1] to [3] ,
An adhesive film in which the propylene-based polymer (B2) contains a propylene-based elastomer.
[ 5 ]
In the adhesive film according to any one of the above [1] to [ 4 ],
An adhesive film having a thickness of 100 μm or less of the adhesive resin layer.
[ 6 ]
In the adhesive film according to any one of the above [1] to [ 5 ],
An adhesive film having a thickness of the uneven absorbing resin layer of 10 μm or more and 500 μm or less.
[ 7 ]
In the adhesive film according to any one of the above [1] to [ 6 ],
The circuit forming surface of the electronic component is an adhesive film containing a bump electrode.

According to the present invention, it is possible to provide an adhesive film having an excellent balance between unevenness absorption and cutability.

It is sectional drawing which shows typically an example of the structure of the adhesive film of embodiment which concerns on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, similar components are designated by a common reference numeral, and the description thereof will be omitted as appropriate. Further, the figure is a schematic view and does not match the actual dimensional ratio. Unless otherwise specified, "A to B" in the numerical range represent A or more and B or less. Further, in the present embodiment, "(meth) acrylic" means acrylic, methacrylic acid or both acrylic and methacrylic acid.

1. 1. Adhesive film FIG. 1 is a cross-sectional view schematically showing an example of the structure of the adhesive film 100 according to the embodiment of the present invention.
As shown in FIG. 1, the adhesive film 100 according to the present embodiment is an adhesive film used for protecting the circuit forming surface of an electronic component or fixing an electronic component, and has a base material layer 10 and unevenness. The absorbent resin layer 20 and the adhesive resin layer 30 are provided in this order, and the uneven absorbent resin layer is tearable from the cut when the following tear test is performed.
A press sheet having a thickness of 1.0 ± 0.1 mm × a length of 150 mm × a width of 50 mm produced by using the uneven absorbent resin layer is produced. Next, a cut having a length of 75 mm is made in the vertical direction of the press sheet. Next, using a tensile tester, the press sheet is torn in the direction of 180 ° starting from the cut in the press sheet under the conditions of 23 ° C. and a tensile speed of 200 mm / min.
Here, it was evaluated that the one in which tearing progressed from the cut and could be torn was evaluated as tearable, and the one in which the resin layer was only stretched without tearing and could not be torn was evaluated as not incapable of tearing.

As described above, for electronic components having large irregularities on the circuit forming surface, an uneven absorption resin layer is provided between the base film and the adhesive resin layer in order to impart unevenness absorption to the adhesive film. Adhesive films are being considered.
However, according to the study by the present inventors, the adhesive film including the base material layer, the unevenness-absorbing resin layer, and the adhesive resin layer in this order absorbs the unevenness of the circuit forming surface of the electronic component. Although it has excellent properties, it has become clear that burrs are likely to occur when cutting to the size of electronic components. If the adhesive film has burrs, the electronic component may be cracked or scratched when the electronic component is ground or when the adhesive film is peeled off from the electronic component.
The present inventors have made extensive studies to achieve the above-mentioned problems. As a result, it is said that the characteristics of the unevenness-absorbing resin layer have a great influence on the cutability of the adhesive film having the base material layer, the unevenness-absorbing resin layer, and the adhesive resin layer in this order. I got the knowledge.
As a result of further diligent studies based on the above findings, the present inventors have achieved good unevenness absorption of the adhesive film by using the unevenness-absorbing resin layer that can be torn when the tearing test is performed. For the first time, I found that it is possible to improve the cutability while maintaining the above.
That is, according to the present embodiment, the unevenness absorbing resin layer 20 that can be torn when the tearing test is performed is provided between the base material layer 10 and the adhesive resin layer 30. And an adhesive film having an excellent balance of cutability can be obtained.

The thickness of the entire adhesive film 100 according to the present embodiment is preferably 25 μm or more and 1100 μm or less, more preferably 100 μm or more and 900 μm or less, and further preferably 200 μm or more and 800 μm from the viewpoint of the balance between mechanical properties and handleability. Hereinafter, it is particularly preferably 300 μm or more and 600 μm or less.

The adhesive film 100 according to the present embodiment may be provided with another layer such as an adhesive layer or an antistatic layer (not shown) between the layers as long as the effect of the present invention is not impaired. According to the adhesive layer, the adhesiveness between the layers can be improved. Further, according to the antistatic layer, the antistatic property of the adhesive film 100 can be improved.

The adhesive film 100 according to the present embodiment is used for protecting the surface of an electronic component and fixing the electronic component in the manufacturing process of the electronic device, and more specifically, in the manufacturing process of the electronic device. It is suitably used as a back grind tape used for protecting a circuit forming surface (that is, a circuit surface including a circuit pattern) of an electronic component in one back grind process.

Next, each layer constituting the adhesive film 100 according to the present embodiment will be described.

<Base layer>
The base material layer 10 is a layer provided for the purpose of improving the handleability, mechanical properties, heat resistance, and other properties of the adhesive film 100.
The base material layer 10 is not particularly limited as long as it has mechanical strength capable of withstanding an external force applied when processing an electronic component, and examples thereof include a resin film.
As the resin constituting the base material layer 10, a known thermoplastic resin can be used. For example, polyolefins such as polyethylene, polypropylene, poly (4-methyl-1-pentene), poly (1-butene); polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate; nylon-6, nylon-66, poly. Polyamides such as metaxylene adipamide; polyacrylates; polymethacrylates; polyvinyl chloride; polyimides; polyetherimides; polyamideimides; ethylene / vinyl acetate copolymers; polyacrylonitrile; polycarbonates; polystyrenes; ionomers; polysulfones; polyethers One or more selected from sulfone; polyether ether ketone; polyphenylene sulfide; polyphenylene ether; polyester-based elastomer, polyamide-based elastomer, polyimide-based elastomer, polyethylene such as polybutylene terephthalate; and the like can be mentioned.
Among these, from the viewpoint of improving transparency, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyimide, ethylene / vinyl acetate copolymer, polyester elastomer, polyamide elastomer, polyimide elastomer, and polybutylene terephthalate. One or more selected from the above is preferable, and one or more selected from polyethylene terephthalate, polyethylene naphthalate, polyester elastomer, polyamide elastomer, polyimide elastomer, polybutylene terephthalate and polyimide is more preferable.
Further, from the viewpoint of improving the balance between the properties such as flexibility and elasticity of the adhesive film 100 and the heat resistance, the resin constituting the base material layer 10 includes polyester-based elastomers, polyamide-based elastomers, and polyimide-based elastomers. And one or more selected from polybutylene terephthalate and the like are more preferable.

The base material layer 10 may be a single layer or two or more types of layers.
Further, the form of the resin film used for forming the base material layer 10 may be a stretched film or a film stretched in a uniaxial direction or a biaxial direction, but the base material layer 10 may be used. From the viewpoint of improving the mechanical strength of the film, it is preferable that the film is stretched in the uniaxial direction or the biaxial direction.

The thickness of the base material layer 10 is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 300 μm or less, and further preferably 25 μm or more and 150 μm or less from the viewpoint of obtaining good film characteristics.
The base material layer 10 may be surface-treated in order to improve the adhesiveness with other layers. Specifically, corona treatment, plasma treatment, undercoat treatment, primer coating treatment and the like may be performed.

<Concave and convex absorbent resin layer>
The adhesive film 100 according to the present embodiment includes a concave-convex absorbent resin layer 20 between the base material layer 10 and the adhesive resin layer 30.
The unevenness absorbing resin layer 20 is a layer provided for the purpose of improving the followability of the adhesive film 100 to the circuit forming surface and improving the adhesion between the circuit forming surface and the adhesive film 100.
Further, the unevenness-absorbing resin layer 20 has a feature that when the tear test described above is performed, tearing progresses from the cut and tearing is possible. By providing such an unevenness absorbing resin layer 20, the cuttability of the adhesive film 100 according to the present embodiment can be improved.
Here, the tearability characteristic of the unevenness-absorbing resin layer 20 can be realized, for example, by controlling the type and blending ratio of each resin component constituting the unevenness-absorbing resin layer 20.

The tear strength of the unevenness-absorbing resin layer 20 measured by the tear test below is preferably 0.5 N / mm or more, more preferably 1 from the viewpoint of improving the mechanical strength and handleability of the adhesive film 100. It is 0.0 N / mm or more, more preferably 2.0 N / mm or more, and from the viewpoint of further improving the cuttability of the adhesive film 100, it is preferably 10 N / mm or less, more preferably 8.0 N / mm or less, and further. It is preferably 6.0 N / mm or less.
(Tear test)
A press sheet having a thickness of 1.0 ± 0.1 mm × a length of 150 mm × a width of 50 mm produced by using the unevenness-absorbing resin layer 20 is produced. Next, a cut having a length of 75 mm is made in the vertical direction of the press sheet. Next, using a tensile tester, the press sheet is torn in a direction of 180 ° starting from the cut of the press sheet under the conditions of 23 ° C. and a tensile speed of 200 mm / min, and the tear strength at that time is measured.
Here, other than the above conditions and methods, conditions and methods based on the trouser tearing method specified in JIS K7128-1 can be adopted.
The tear strength of the unevenness-absorbing resin layer 20 can be controlled within the above range by, for example, controlling the type and blending ratio of each resin component constituting the unevenness-absorbing resin layer 20.

Examples of the resin constituting the uneven absorption resin layer 20 include an ethylene / α-olefin copolymer (A), an ethylene / polar monomer copolymer (B1), and a propylene-based polymer (B2).
From the viewpoint of obtaining the concavo-convex-absorbing resin layer 20 that can be torn and adjusting the tear strength of the concavo-convex-absorbing resin layer 20 within the above range, the concavo-convex-absorbing resin layer 20 is an ethylene / α-olefin copolymer ( It is preferable to contain A) and at least one polymer (B) selected from the ethylene / polar monomer copolymer (B1) and the propylene-based polymer (B2).

In the adhesive film 100 according to the present embodiment, when the total amount of the ethylene / α-olefin copolymer (A) and the polymer (B) contained in the unevenness-absorbing resin layer 20 is 100 parts by mass, the unevenness absorption is performed. The content of the polymer (B) in the sex resin layer 20 is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, from the viewpoint of improving the unevenness absorption. Further, the content of the polymer (B) in the uneven absorbing resin layer 20 is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and 30 parts by mass or less from the viewpoint of improving the cutability. Especially preferable.

In the adhesive film 100 according to the present embodiment, it is preferable that the uneven absorbing resin layer 20 forms a sea-island structure from the viewpoint of further improving the cutability. When the uneven absorbing resin layer 20 forms the sea island structure, at least the ethylene / α-olefin copolymer (A) is present in the sea phase in the sea island structure, and the polymer (B) is present in the island phase in the sea island structure. It is preferable that the structure is at least present.
Such a sea-island structure can be observed, for example, by a transmission electron microscope (TEM) image.

(Ethylene / α-olefin copolymer (A))
The ethylene / α-olefin copolymer (A) according to the present 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, one type of α-olefin having 3 to 20 carbon atoms can be used alone or two or more types can be used in combination. Of these, α-olefins having 10 or less carbon atoms are preferable, and α-olefins having 3 to 8 carbon atoms are particularly preferable. Specific examples of such α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3,3-dimethyl-1-butene, and 4-methyl-1-. Penten, 1-octene, 1-decene, 1-dodecene and the like can be mentioned. Of these, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene and 1-octene are preferable because of their availability. The ethylene / α-olefin copolymer (A) may be a random copolymer or a block copolymer, but a random copolymer is preferable from the viewpoint of flexibility.

Here, as the ethylene / α-olefin copolymer (A), for example, Toughmer (trademark registration) manufactured by Mitsui Chemicals, ENGAGE (trademark registration) manufactured by DOW, and EXACT (trademark registration) manufactured by ExxonMobil Co., Ltd. , Kernel (trademark registration) manufactured by Nippon Polyethylene Co., Ltd., etc.

The melt flow rate (MFR) of the ethylene / α-olefin copolymer (A) measured at 190 ° C. and a 2.16 kg load according to ASTM D1238 is preferably 0.1 to 50 g / 10. Minutes, more preferably 0.2 to 30 g / 10 minutes, still more preferably 0.5 to 20 g / 10 minutes, and particularly preferably 1.0 to 10 g / 10 minutes.
When the MFR is at least the above lower limit value, the fluidity of the ethylene / α-olefin copolymer (A) is improved, and the processability of the uneven absorbing resin layer 20 can be further improved.
Further, when the MFR is not more than the above upper limit value, the unevenness absorbing resin layer 20 having a more uniform thickness can be obtained.

(Ethylene / Polar Monomer Copolymer (B1))
Examples of the ethylene / polar monomer copolymer (B1) according to the present embodiment include an ethylene / (meth) ethyl acrylate copolymer, an ethylene / (meth) methyl acrylate copolymer, and an ethylene / (meth) acrylic. Cyclic acid propyl copolymer, ethylene (meth) butyl acrylate copolymer, ethylene (meth) hexyl acrylate copolymer, ethylene (meth) acrylate-2-hydroxyethyl copolymer, ethylene (meth) ) Acrylic acid-2-hydroxypropyl copolymer, ethylene / glycidyl (meth) acrylate copolymer, ethylene / maleate dimethyl copolymer, ethylene / maleate diethyl copolymer, ethylene / fumarate dimethyl copolymer , Ethylene / unsaturated carboxylic acid ester copolymer such as ethylene / diethyl fumaric acid copolymer; ethylene / (meth) acrylic acid copolymer, ethylene / maleic acid copolymer, ethylene / fumaric acid copolymer, ethylene -Antiethylene-unsaturated carboxylic acid copolymers such as crotonic acid copolymers and salts thereof; ethylene-vinyl acetate copolymers, ethylene-vinyl propionate copolymers, ethylene-vinyl butyrate copolymers, ethylene-steer Ethylene / vinyl ester copolymers such as vinyl acid acid copolymers: One or more selected from ethylene / styrene copolymers and the like can be mentioned.
Among these, the ethylene / polar monomer copolymer is one or two selected from the ethylene / vinyl ester copolymer and the ethylene / unsaturated carboxylic acid ester copolymer in terms of the balance between availability and performance. It is preferable to contain seeds or more, and it is particularly preferable to contain an ethylene / vinyl acetate copolymer.

The ethylene-vinyl acetate copolymer is a copolymer of ethylene and vinyl acetate, and is, for example, a random copolymer.
The content ratio of the structural unit derived from vinyl acetate in the ethylene-vinyl acetate copolymer is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 45% by mass or less, and further preferably 15% by mass. % Or more and 40% by mass or less. When the content of vinyl acetate is in this range, the adhesive film 100 is further excellent in the balance of flexibility, heat resistance, transparency and mechanical properties. Further, when the unevenness-absorbing resin layer 20 is formed, the film forming property is improved.
The vinyl acetate content can be measured according to JIS K7192: 1999.

The ethylene / vinyl acetate copolymer is preferably a binary copolymer composed of only ethylene and vinyl acetate, but in addition to ethylene and vinyl acetate, for example, vinyl formate, vinyl glycolate, vinyl propionate, vinyl benzoate, etc. Vinyl ester-based monomers such as; acrylic acid, methacrylic acid, etacrilic acid, or acrylic monoweights such as salts thereof or alkyl esters; or the like; one or more selected from the above may be contained as a copolymerization component. .. When the copolymer component other than ethylene and vinyl acetate is contained, the amount of the copolymer component other than ethylene and vinyl acetate in the ethylene / vinyl acetate copolymer may be 0.5% by mass or more and 5% by mass or less. preferable.

The melt flow rate (MFR) of the ethylene / polar monomer copolymer (B1) measured at 190 ° C. and a load of 2.16 kg according to JIS K7210: 1999 is preferably 0.1 to 50 g / g. It is 10 minutes, more preferably 0.2 to 45 g / 10 minutes, still more preferably 0.5 to 40 g / 10 minutes.
When the MFR is at least the above lower limit value, the fluidity of the ethylene / polar monomer copolymer (B1) is improved, and the molding processability of the uneven absorbing resin layer 20 can be further improved.
Further, when the MFR is not more than the above upper limit value, the molecular weight becomes high, so that the chill roll or the like is less likely to adhere to the roll surface, and the unevenness absorbing resin layer 20 having a more uniform thickness can be obtained.

(Propylene polymer (B2))
Examples of the propylene-based polymer (B2) according to the present embodiment include polypropylene, propylene-based elastomer (c), and the like. The propylene-based polymer (B2) according to the present embodiment may be used alone or in combination of two or more.
Among these, the propylene-based elastomer (c) is preferable as the propylene-based polymer (B2) from the viewpoint of being more excellent in mixing with the ethylene / α-olefin copolymer (A).

The melt flow rate (MFR) of the propylene-based polymer (B2) according to the present embodiment measured under the conditions of 230 ° C. and a 2.16 kg load according to ASTM D1238 is preferable from the viewpoint of fluidity and moldability. Is 0.5 g / 10 minutes or more, more preferably 1 g / 10 minutes or more, preferably 20 g / 10 minutes or less, more preferably 10 g / 10 minutes or less, still more preferably, from the viewpoint of further stabilizing moldability. 7 g / 10 minutes or less.

As the propylene-based elastomer (c) according to the present embodiment, for example, a propylene / α-olefin copolymer (c1) can be used. The propylene-based elastomer (c) according to the present embodiment may further contain polypropylene (c2).

The propylene / α-olefin copolymer (c1) is a copolymer of propylene and an α-olefin other than propylene. The α-olefin in the propylene / α-olefin copolymer (c1) is preferably an α-olefin having 2 to 20 carbon atoms. Examples of α-olefins having 2 to 20 carbon atoms include ethylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene and the like, preferably. Ethylene, 1-butene. The α-olefin contained in the propylene / α-olefin copolymer (c1) may be one kind or a combination of two or more kinds. The propylene / α-olefin copolymer (c1) is more preferably a propylene / 1-butene / ethylene copolymer.

Polypropylene (c2) is substantially a homopolymer of propylene, but may contain a trace amount of α-olefin or the like other than propylene, so-called homopolypropylene (hPP), random polypropylene (rPP) and block polypropylene (bPP). Any of them may be used.

The content of polypropylene (c2) is preferably 1 to 70 parts by mass, more preferably 5 to 50 parts by mass, when the total amount of the propylene-based elastomer (c) according to the present embodiment is 100 parts by mass. It is more preferably 5 to 30 parts by mass, and particularly preferably 5 to 20 parts by mass.

The unevenness-absorbing resin layer 20 can be obtained, for example, by dry-blending or melt-kneading each component and then extrusion-molding.

The thickness of the unevenness-absorbing resin layer 20 is not particularly limited as long as it can embed the unevenness of the circuit forming surface of the electronic component, but is preferably 10 μm or more and 500 μm or less, preferably 20 μm or more and 450 μm. It is more preferably 30 μm or more, and further preferably 400 μm or less.

<Adhesive resin layer>
The adhesive film 100 according to the present embodiment includes an adhesive resin layer 30.
The adhesive resin layer 30 is a layer provided on one surface side of the unevenness absorbing resin layer 20, and when the adhesive film 100 is attached to the circuit forming surface of the electronic component, it comes into contact with the circuit forming surface of the electronic component. It is a layer that adheres to the surface.

Examples of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive resin layer 30 include (meth) acrylic pressure-sensitive adhesive, silicone-based pressure-sensitive adhesive, urethane-based pressure-sensitive adhesive, olefin-based pressure-sensitive adhesive, and styrene-based pressure-sensitive adhesive. Among these, a (meth) acrylic pressure-sensitive adhesive using a (meth) acrylic resin as a base polymer is preferable because the adhesive strength can be easily adjusted.

Further, as the pressure-sensitive adhesive constituting the pressure-sensitive adhesive resin layer 30, it is preferable to use a radiation cross-linking type pressure-sensitive adhesive whose adhesive strength is reduced by radiation.
Since the adhesive resin layer 30 composed of the radiation-crosslinked adhesive is crosslinked by irradiation with radiation and the adhesive force is significantly reduced, the electronic parts can be easily peeled off from the adhesive film 100. Examples of radiation include ultraviolet rays, electron beams, and infrared rays.
As the radiation cross-linking type pressure-sensitive adhesive, an ultraviolet cross-linking type pressure-sensitive adhesive is preferable.

Examples of the (meth) acrylic resin 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, and the like. Be done. 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, and hydroxypropyl (meth). Examples thereof include 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 the comonomer constituting the (meth) acrylic copolymer include vinyl acetate, (meth) acrylonitrile, styrene, (meth) acrylic acid, itaconic acid, (meth) acrylic amide, and methylol (meth) acrylic. Examples thereof include acrylamide and maleic anhydride. These comonomer may be used alone or in combination of two or more.

As the radiation cross-linking type (meth) acrylic pressure-sensitive adhesive, a (meth) acrylic resin having a polymerizable carbon-carbon double bond in the molecule and two or more polymerizable carbon-carbon double bonds in the molecule are used. An example of a pressure-sensitive adhesive obtained by cross-linking the above (meth) acrylic resin with a cross-linking agent, which contains a low-molecular-weight compound and a photoinitiator, if necessary.

A (meth) acrylic resin having a polymerizable carbon-carbon double bond in the molecule is specifically obtained as follows. First, a monomer having an ethylenic double bond and a copolymerizable monomer having a functional group (P) are copolymerized. Next, the functional group (P) contained in this copolymer and the monomer having a functional group (Q) capable of causing an addition reaction, a condensation reaction, etc. with the functional group (P) are double-bonded in the monomer. The reaction is carried out while leaving the above, and a polymerizable carbon-carbon double bond is introduced into the copolymer molecule.

Examples of the monomer having an ethylenic double bond include acrylic acid alkyl esters such as methyl (meth) acrylate, -2-ethylhexyl (meth) acrylate, butyl (meth) acrylate, and ethyl (meth) acrylate. And one or more of the monomers having an ethylenic double bond such as an alkyl methacrylate ester monomer, a vinyl ester such as vinyl acetate, (meth) acrylonitrile, (meth) acrylamide, and styrene are used.

Examples of the copolymerizable monomer having the functional group (P) include (meth) acrylic acid, maleic acid, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, N-methylol (meth) acrylamide, and (meth). ) Acryloyloxyethyl isocyanate and the like can be mentioned. These may be used alone or in combination of two or more.
The ratio of the monomer having an ethylenic double bond to the copolymerizable monomer having a functional group (P) is 70 to 99% by mass of the monomer having an ethylenic double bond and has a functional group (P). The copolymerizable monomer is preferably 1 to 30% by mass. More preferably, the monomer having an ethylenic double bond is 80 to 95% by mass, and the copolymerizable monomer having a functional group (P) is 5 to 20% by mass.
Examples of the monomer having the functional group (Q) include a monomer similar to the copolymerizable monomer having the functional group (P).

A functional group (P) and a functional group to be reacted when a polymerizable carbon-carbon double bond is introduced into a copolymer of a monomer having an ethylenic double bond and a copolymerizable monomer having a functional group (P). As the combination of (Q), a combination such as a carboxyl group and an epoxy group, a carboxyl group and an aziridyl group, a hydroxyl group and an isocyanate group, etc., in which an addition reaction easily occurs is desirable. Further, not limited to the addition reaction, any reaction may be used as long as it is a reaction in which a polymerizable carbon-carbon double bond can be easily introduced, such as a condensation reaction between a carboxylic acid group and a hydroxyl group.

Examples of the low molecular weight compound having two or more polymerizable carbon-carbon double bonds in the molecule include tripropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetraacrylate, and pentaerythritol. Examples thereof include tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate. These may be used alone or in combination of two or more. The amount of the low molecular weight compound having two or more polymerizable carbon-carbon double bonds in the molecule is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin. More preferably, it is 5 to 18 parts by mass.

Examples of the photoinitiator include benzoin, isopropylbenzoin ether, isobutylbenzoin ether, benzophenone, Michler ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, acetophenone diethyl ketal, benzyl dimethyl ketal, 1-hydroxycyclohexylphenyl ketone, 2 -Hydroxy-2-methyl-1-phenylpropane-1-one and the like can be mentioned. These may be used alone or in combination of two or more. The amount of the photoinitiator added is preferably 0.1 to 15 parts by mass, and more preferably 5 to 10 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin.

A cross-linking agent may be added to the ultraviolet curable pressure-sensitive adhesive. Examples of the cross-linking agent include epoxy compounds such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, and diglycerol polyglycidyl ether, and tetramethylolmethane-tri-β-aziridinyl propionate. Trimethylolpropane-tri-β-aziridinyl propionate, N, N'-diphenylmethane-4,4'-bis (1-aziridinecarboxyamide), N, N'-hexamethylene-1,6-bis ( Examples thereof include aziridin-based compounds such as 1-azilysin carboxylamide), and isocyanate-based compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, and polyisocyanate. The ultraviolet curable pressure-sensitive adhesive may be any of a solvent type, an emulsion type, a hot melt type and the like.

The content of the cross-linking agent is usually preferably in a range such that the number of functional groups in the cross-linking agent does not become larger than the number of functional groups in the (meth) acrylic resin. However, if a new functional group is generated in the cross-linking reaction or the cross-linking reaction is slow, the cross-linking reaction may be excessively contained as needed.
The content of the cross-linking agent in the (meth) acrylic pressure-sensitive adhesive is 0. It is preferably 1 part by mass or more and 15 parts by mass or less.

The adhesive resin layer 30 can be formed, for example, by applying a pressure-sensitive adhesive coating liquid on the unevenness-absorbing resin layer 20.
As a method for applying the pressure-sensitive adhesive coating liquid, for example, a conventionally known 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, or a die coater method can be adopted. .. The drying conditions of the applied pressure-sensitive adhesive are not particularly limited, but in general, it is preferable to dry the applied adhesive in a temperature range of 80 to 200 ° C. for 10 seconds to 10 minutes. More preferably, it is dried at 80 to 170 ° C. for 15 seconds to 5 minutes. In order to sufficiently promote the cross-linking reaction between the cross-linking agent and the (meth) acrylic resin, the pressure-sensitive adhesive coating liquid may be heated at 40 to 80 ° C. for about 5 to 300 hours after the drying is completed.

In the adhesive film 100 according to the present embodiment, the thickness of the adhesive resin layer 30 is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 3 μm or more and 80 μm or less, and 5 μm or more and 60 μm. The following is more preferable.

Next, an example of the method for manufacturing the adhesive film 100 according to the present embodiment will be described.
First, the unevenness-absorbing resin layer 20 is extruded and laminated on one surface of the base material layer 10 by a laminating method. Next, the adhesive resin layer 30 is formed by applying the pressure-sensitive adhesive coating liquid on the unevenness-absorbing resin layer 20 and drying it, and the pressure-sensitive adhesive film 100 can be obtained.
Further, the base material layer 10 and the unevenness absorbing resin layer 20 may be formed by coextrusion molding, or the film-shaped base material layer 10 and the film-shaped unevenness absorbing resin layer 20 are laminated. May be formed.

2. 2. Grinding method using an adhesive film Next, a grinding method (back grind) of a surface (hereinafter, also referred to as a back surface) opposite to the circuit forming surface of an electronic component using the adhesive film 100 according to the present embodiment. Also called.) An example will be described. The method for grinding the back surface of an electronic component according to the present embodiment is characterized in that the adhesive film 100 according to the present embodiment is used as a back grind tape when grinding the back surface of the electronic component.

First, the circuit forming surface of the electronic component is attached on the adhesive resin layer 30 of the adhesive film 100.
The electronic component to be attached to the adhesive film 100 is not particularly limited as long as it is an electronic component having a circuit forming surface, and examples thereof include a semiconductor wafer, a molded wafer, a mold panel, a mold array package, and a semiconductor substrate, and are preferable. It is a semiconductor wafer.
Examples of the semiconductor substrate include a silicon substrate, a sapphire substrate, a germanium substrate, a germanium-arsenic substrate, a gallium-phosphosphide substrate, a gallium-arsenide-aluminum substrate, a gallium-arsenide substrate, and a lithium tantalate substrate.

The circuit forming surface of the electronic component is an uneven surface, for example, by having an electrode.
Further, for example, when an electronic device is mounted on a mounting surface, the electrodes are joined to the electrodes formed on the mounting surface, and electricity is supplied between the electronic device and the mounting surface (mounting surface such as a printed substrate). It forms a target connection.
Examples of the electrode include bump electrodes such as ball bumps, printed bumps, stud bumps, plated bumps, and pillar bumps. That is, the electrode is usually a convex electrode. These bump electrodes may be used alone or in combination of two or more.
The metal type 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.

Next, the electronic component is fixed to the chuck table or the like of the grinder via the base material layer 10 of the adhesive film 100, and the back surface (circuit non-formed surface) of the electronic component is ground. Here, grinding means thinning to a predetermined thickness without breaking or damaging the electronic component. After the grinding is finished, the adhesive film 100 is peeled off from the electronic component. After the grinding of the back surface of the electronic component is completed, a chemical etching step may be performed before the adhesive film 100 is peeled off. Further, if necessary, after the adhesive film 100 is peeled off, the surface of the electronic component is subjected to treatments such as water washing and plasma washing.

The operation of attaching the electronic component to the adhesive film 100 may be performed manually, but it can generally be performed by a device called an automatic attaching machine to which a roll-shaped adhesive film is attached.

The back surface grinding method is not particularly limited, and for example, a known grinding method such as a through feed method or an in-feed method can be adopted. Each grinding can be performed while cooling water by applying it to an electronic component and a grindstone. After the back surface grinding is completed, chemical etching is performed as necessary. Chemical etching adheres to an etching solution selected from the group consisting of an acidic aqueous solution consisting of a single or mixed solution of hydrofluoric acid, nitric acid, sulfuric acid, acetic acid, etc., an aqueous solution of potassium hydroxide, an aqueous solution of sodium hydroxide, etc. This is performed by a method such as immersing an electronic component in a state where the sex film 100 is attached. The etching is performed for the purpose of removing the strain generated on the back surface of the electronic component, further thinning the electronic component, removing the oxide film and the like, and pretreating when forming the electrode on the back surface. The etching solution is appropriately selected according to the above purpose.

After the back surface grinding and chemical etching are completed, the adhesive film 100 is peeled off from the surface of the electronic component. This series of operations may be performed manually, but can be performed by a device generally called an automatic peeling machine.

The surface of the electronic component after peeling off the adhesive film 100 may be washed if necessary. Examples of the cleaning method include wet cleaning such as water cleaning and solvent cleaning, and dry cleaning such as plasma cleaning. In the case of wet cleaning, ultrasonic cleaning may be used in combination. These cleaning methods can be appropriately selected depending on the state of contamination of the surface of the electronic component.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted.
The reference form will be added below.
[1]
An adhesive film used to protect the circuit forming surface of electronic components or to fix electronic components.
A base material layer, an uneven absorption resin layer, and an adhesive resin layer are provided in this order.
The concavo-convex absorbent resin layer is an adhesive film that can be torn as the tear progresses from the cut when the following tear test is performed.
(Tear test)
A press sheet having a thickness of 1.0 ± 0.1 mm × a length of 150 mm × a width of 50 mm produced by using the uneven absorbent resin layer is produced. Next, a cut having a length of 75 mm is made in the vertical direction of the press sheet. Next, using a tensile tester, the press sheet is torn in the direction of 180 ° starting from the cut in the press sheet under the conditions of 23 ° C. and a tensile speed of 200 mm / min.
[2]
In the adhesive film according to the above [1],
An adhesive film having a tear strength of 0.5 N / mm or more and 10 N / mm or less as measured by the tear test.
[3]
In the adhesive film according to the above [1] or [2],
The uneven absorbent resin layer is
An ethylene / α-olefin copolymer (A) and at least one polymer (B) selected from an ethylene / polar monomer copolymer (B1) and a propylene-based polymer (B2).
Adhesive film including.
[4]
In the adhesive film according to the above [3],
An adhesive film in which the ethylene / polar monomer copolymer (B1) contains an ethylene / vinyl acetate copolymer.
[5]
In the adhesive film according to the above [3],
An adhesive film in which the propylene-based polymer (B2) contains a propylene-based elastomer.
[6]
In the adhesive film according to any one of the above [1] to [5],
An adhesive film having a thickness of 100 μm or less of the adhesive resin layer.
[7]
In the adhesive film according to any one of the above [1] to [6],
Adhesive film that is a back grind tape.
[8]
In the adhesive film according to any one of the above [1] to [7],
An adhesive film having a thickness of the uneven absorbing resin layer of 10 μm or more and 500 μm or less.
[9]
In the adhesive film according to any one of the above [1] to [8],
The circuit forming surface of the electronic component is an adhesive film containing a bump electrode.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.
Details regarding the production of the adhesive film are as follows.

<Resin for forming a concave-convex absorbent resin layer>
Resin 1: Ethylene / propylene copolymer (manufactured by Mitsui Chemicals, trade name: Toughmer P0275, density: 861 kg / m ³ , melt flow rate (190 ° C): 2.9 g / 10 minutes)
Resin 2: Ethylene-vinyl acetate copolymer (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: Evaflex EV170, vinyl acetate content: 33% by mass, density: 960 kg / m ³ , melt flow rate (190 ° C): 1 g / 10 minutes)
Resin 3: Ethylene-vinyl acetate copolymer (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name: Evaflex EV150, vinyl acetate content: 33% by mass, density: 960 kg / m ³ , melt flow rate (190 ° C): 30 g / 10 minutes)
Resin 4: Propylene elastomer (manufactured by Mitsui Chemicals, trade name: Toughmer PN3560, density: 866 kg / m ³ , melt flow rate (230 ° C): 6.0 g / 10 minutes)

<Adhesive polymer (acrylic resin)>
49 parts by mass of ethyl acrylate, 20 parts by mass of -2-ethylhexyl acrylate, 21 parts by mass of methyl acrylate, 10 parts by mass of glycidyl methacrylate, and 0.5 parts by mass of benzoyl peroxide as a polymerization initiator were mixed. The obtained mixture was added dropwise to a nitrogen substitution flask containing 65 parts by mass of toluene and 50 parts by mass of ethyl acetate at 80 ° C. for 5 hours with stirring, and the mixture was further stirred for 5 hours for reaction. After completion of the reaction, the obtained solution was cooled, 25 parts by mass of xylene, 5 parts by mass of acrylic acid, and 0.5 part by mass of tetradecyldimethylbenzylammonium chloride were added to the cooled solution, and 32 by mass of air was blown at 85 ° C. The reaction was carried out for a long time to obtain a pressure-sensitive adhesive polymer solution.

<Adhesive coating liquid A for adhesive resin layer>
7 parts by mass of benzyl dimethyl ketal (manufactured by BASF, trade name: Irgacure 651) as a photoinitiator, and isocyanate-based cross-linking agent (manufactured by Mitsui Chemicals, trade name: ole) with respect to 100 parts by mass of the pressure-sensitive adhesive polymer (solid content). 2 parts by mass of Star P49-75S) and 12 parts by mass of dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-400) were added to obtain a pressure-sensitive adhesive coating liquid A for the pressure-sensitive adhesive resin layer.

<Adhesive coating liquid B for adhesive resin layer>
7 parts by mass of benzyl dimethyl ketal (manufactured by BASF, trade name: Irgacure 651) as a photoinitiator, and isocyanate-based cross-linking agent (manufactured by Mitsui Chemicals, trade name: ole) with respect to 100 parts by mass of the pressure-sensitive adhesive polymer (solid content). 1 part by mass of Star P49-75S) and 12 parts by mass of dipentaerythritol hexaacrylate (manufactured by Toagosei Co., Ltd., trade name: Aronix M-400) were added to obtain a pressure-sensitive adhesive coating liquid B for the pressure-sensitive adhesive resin layer.

[Example 1]
Toughmer P0275 (80 parts by mass), Evaflex EV170 (15 parts by mass) and Toughmer PN3560 (5 parts by mass), which are the uneven absorbing resin layers, were dry-blended. Next, a dry blend of the above-mentioned unevenness-absorbing resin is extruded and laminated on a polyethylene terephthalate film (50 μm) to be a base material layer so as to have a thickness of 380 μm using a single-screw extruder, and the base material layer is formed. And a laminated film of the uneven absorption resin layer was obtained. At that time, only the unevenness-absorbing resin layer was separately obtained, and the tear strength was measured as follows. The results obtained are shown in Table 1.

<Measurement of tear strength>
In order to remove the orientation characteristics at the time of molding, the uneven absorbing resin layers were laminated so that the MD direction and the TD direction became a cross, and then press-molded using a vacuum press machine to obtain a press sheet (size). : 170 mm x 170 mm, thickness: 1 mm, press temperature: 180 ° C., 1 minute after preheating, pressurized at 8 MPa under vacuum for 4 minutes). One day after molding the press sheet, a test piece having a size of 150 mm × 50 mm was cut out from the press sheet. Next, a slit (cut) having a length of 75 mm was made in the center of the test piece in the vertical direction, and the trouser tear strength was measured using a tensile tester (tensile speed: 200 mm / min, measurement environment temperature: 23 ° C.). The tear strength (N) divided by the sheet thickness (mm) was taken as the tear strength. The test was performed three times, and the average value was adopted.

Next, the pressure-sensitive adhesive coating liquid A for the pressure-sensitive adhesive resin layer was applied to a silicone terephthalate film (separator) that had been subjected to a silicone release treatment, and then dried to form a pressure-sensitive adhesive resin layer having a thickness of 10 μm. Next, the obtained adhesive resin layer was bonded to the unevenness-absorbing resin layer side of the above-mentioned laminated film to obtain an adhesive film. The following cut burr number evaluation was performed on the obtained adhesive film. The results obtained are shown in Table 1.

<Evaluation of the number of cut burrs>
The adhesive film was attached to a 12-inch mirror wafer using a back surface grinding tape affixing machine (Nitto Seiki Co., Ltd., DR3000II), and the outer periphery was cut (table temperature: 70 ° C., laminating load: 90%, laminating speed: 2 mm). / s, Cutter heater: OFF, Cutter low speed: 75 mm / s, Cutter high speed: 100 mm / s, Cutter acceleration / deceleration: 100 mm / s ² , Peeling speed: 50 mm / s). The outer peripheral portion of the film cut portion of the obtained film-attached wafer was observed with an optical microscope, and the number of burrs of 200 μm or more was measured.

[Example 2]
A laminated film of the base material and the unevenness-absorbing resin layer was produced in the same manner as in Example 1 except that the thickness of the unevenness-absorbing resin layer was changed to 350 μm. Next, an adhesive film was produced in the same manner as in Example 1 except that the adhesive resin layer having a thickness of 40 μm was formed by using the adhesive coating liquid B for the adhesive resin layer. Moreover, the tear strength and the number of cut burrs were evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

[Example 3]
Example 1 except that the unevenness-absorbing resin layer was prepared by using a dry blend of Toughmer P0275 (90 parts by mass) and Toughmer PN3560 (10 parts by mass), and the thickness of the unevenness-absorbing resin layer was 370 μm. In the same manner as above, a laminated film of the base material and the unevenness-absorbing resin layer was produced. Next, an adhesive film was produced in the same manner as in Example 1 except that the adhesive resin layer having a thickness of 20 μm was formed by using the adhesive coating liquid B for the adhesive resin layer. Moreover, the tear strength and the number of cut burrs were evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

[Comparative Example 1]
An uneven absorbing resin layer was prepared using Evaflex EV150, and a laminated film of a base material and an uneven absorbing resin layer was produced in the same manner as in Example 1 except that the thickness of the uneven absorbing resin layer was 350 μm. .. Next, an adhesive film was produced in the same manner as in Example 1 except that the adhesive resin layer having a thickness of 40 μm was formed by using the adhesive coating liquid B for the adhesive resin layer. Further, the trouser tear strength test was carried out in the same manner as in Example 1 except that the pellets of Evaflex EV150 were used and the press temperature was changed to 150 ° C. to prepare a press sheet. Of the three tests, none of them could be torn and the resin stretched, so the maximum strength at that time was determined. In addition, the number of cut burrs was evaluated in the same manner as in Example 1. The results obtained are shown in Table 1.

Here, the adhesive films of Examples 1 to 3 have good adhesion to the semiconductor wafer without cracking the bump electrodes when they are attached to the bump electrode forming surface of the semiconductor wafer having the bump electrodes. Met.
From the above, the adhesive films of Examples 1 to 3 provided with the base material layer, the unevenness-absorbing resin layer, and the adhesive resin layer in this order, and the unevenness-absorbing resin layer can be torn, have unevenness-absorbing properties. And it was excellent in cutability. That is, it can be understood that the adhesive film 100 according to the present embodiment has an excellent balance between unevenness absorption and cutability.
On the other hand, the adhesive film of Comparative Example 1 in which the unevenness-absorbing resin layer was not tearable was excellent in unevenness-absorbing property, but burrs were frequently generated when the film was cut, and the cutability was inferior.

10 Base material layer 20 Concavo-convex absorbent resin layer 30 Adhesive resin layer 100 Adhesive film

Claims (7)

An adhesive film used to protect the circuit forming surface of electronic components or to fix electronic components.
A base material layer, an uneven absorption resin layer, and an adhesive resin layer are provided in this order.
When the following tear test is performed, the uneven absorbent resin layer can be torn because the tear progresses from the cut .
The uneven absorbing resin layer is
It contains an ethylene / α-olefin copolymer (A) and at least one polymer (B) selected from an ethylene / polar monomer copolymer (B1) and a propylene-based polymer (B2).
Adhesive film that is a back grind tape .
(Tear test)
A press sheet having a thickness of 1.0 ± 0.1 mm × a length of 150 mm × a width of 50 mm produced by using the uneven absorbing resin layer is produced. Next, a cut having a length of 75 mm is made in the vertical direction of the press sheet. Next, using a tensile tester, the press sheet is torn in a direction of 180 ° starting from the cut in the press sheet under the conditions of 23 ° C. and a tensile speed of 200 mm / min. In the adhesive film according to claim 1,
An adhesive film having a tear strength of 0.5 N / mm or more and 10 N / mm or less as measured by the tear test. In the adhesive film according to claim 1 or 2 ,
An adhesive film in which the ethylene / polar monomer copolymer (B1) contains an ethylene / vinyl acetate copolymer. In the adhesive film according to any one of claims 1 to 3, the adhesive film
An adhesive film in which the propylene-based polymer (B2) contains a propylene-based elastomer. In the adhesive film according to any one of claims 1 to 4 , the adhesive film
An adhesive film having a thickness of the adhesive resin layer of 100 μm or less. The adhesive film according to any one of claims 1 to 5 .
An adhesive film having a thickness of the uneven absorbing resin layer of 10 μm or more and 500 μm or less. The adhesive film according to any one of claims 1 to 6 .
The circuit forming surface of the electronic component is an adhesive film containing a bump electrode.

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