JPWO2018158858A1 - Adhesive sheet - Google Patents

Abstract

It is an adhesive sheet (10) used when sealing the semiconductor element on an adhesive sheet, Comprising: The said adhesive sheet has a base material (11) and an adhesive layer (12) containing an adhesive composition. wherein the surface free energy of the pressure-sensitive adhesive layer (12) is at 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, and a storage modulus at 100 ° C. of the pressure-sensitive adhesive layer (12) a (Pa), the A pressure-sensitive adhesive sheet in which the numerical value calculated by the following relational expression (1) is 1.5 × 10 ⁻⁵ or more when the thickness of the pressure-sensitive adhesive layer (12) is B (m).
A × B ² (1)

Description

  The present invention relates to an adhesive sheet.

  In recent years, chip size package (CSP) technology has attracted attention as a mounting technology. Of these technologies, a chip-only package that does not use a substrate typified by a wafer level package (WLP) has attracted particular attention in terms of miniaturization and high integration. In such a manufacturing method of WLP or the like, conventionally, a chip to be fixed on a substrate needs to be fixed on another support. Therefore, for example, when manufacturing a semiconductor device, an adhesive sheet is used as a support for temporarily fixing a chip (Patent Document 1 and Patent Document 2).

JP 2012-059934 A JP 2004-014930 A

  However, when a semiconductor device is manufactured using a conventional pressure-sensitive adhesive sheet, when a semiconductor chip attached to the pressure-sensitive adhesive sheet is sealed, the sealing resin leaks and enters between the chip and the pressure-sensitive adhesive sheet. There was a problem of being washed away or floating.

For example, when manufacturing a semiconductor device using an adhesive sheet, the circuit surface of the semiconductor element is fixed to the adhesive layer of the adhesive sheet. On the circuit surface of the semiconductor element, there is a stepped portion such as a dicing line at the periphery of the semiconductor element. And when sealing the semiconductor element on an adhesive sheet, sealing resin embeds the clearance gap between a level | step-difference part and an adhesive layer.
However, it has been found that depending on the type of the sealing resin, the sealing resin cannot fill the gap between the stepped portion and the pressure-sensitive adhesive layer, and a void is formed. If such a gap is formed, the smoothness of the circuit surface of the semiconductor element becomes insufficient, and a problem may occur when forming a pattern on the circuit surface. Therefore, the adhesive sheet is required to have a property that the sealing resin can easily fill the gap between the stepped portion and the adhesive layer (hereinafter sometimes referred to as “filling property”).

  The objective of this invention is providing the adhesive sheet which can make resin leakage prevention property and filling property compatible at the time of sealing the semiconductor element on an adhesive sheet.

According to one aspect of the present invention, it is a pressure-sensitive adhesive sheet used when sealing a semiconductor element on a pressure-sensitive adhesive sheet, and the pressure-sensitive adhesive sheet includes a base material and a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition. the surface free energy of the pressure-sensitive adhesive layer has a 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, and a storage modulus at 100 ° C. of the pressure-sensitive adhesive layer a (Pa), the thickness of the pressure-sensitive adhesive layer B When (m) is set, a pressure-sensitive adhesive sheet having a numerical value calculated by the following relational expression (1) of 1.5 × 10 ⁻⁵ or more is provided.

A × B ² (1)

  In the pressure-sensitive adhesive sheet according to one embodiment of the present invention, the contact angle of 1-bromonaphthalene with respect to the pressure-sensitive adhesive layer is preferably 65 ° or more.

In the pressure-sensitive adhesive sheet according to one embodiment of the present invention, the numerical value calculated by the following relational expression (2) is preferably 1.5 × 10 ⁻¹⁰ or more.

A × B ³ (2)

In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the storage elastic modulus of the substrate at 100 ° C. is preferably 1 × 10 ⁷ Pa or more.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the pressure-sensitive adhesive layer preferably comprises an acrylic pressure-sensitive adhesive composition or a silicone-based pressure-sensitive adhesive composition.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the pressure-sensitive adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive composition, and the acrylic pressure-sensitive adhesive composition preferably contains an acrylic copolymer.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the proportion of the mass of the copolymer component derived from the (meth) acrylic acid alkyl ester in the total mass of the acrylic copolymer is 90% by mass or more. Is preferred.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the alkyl of the alkyl (meth) acrylate preferably has 6 to 8 carbon atoms.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, it is preferable that the acrylic copolymer includes an acrylic copolymer mainly composed of 2-ethylhexyl (meth) acrylate.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the acrylic copolymer preferably includes a copolymer component derived from a monomer having a hydroxyl group.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the proportion of the copolymer component derived from the hydroxyl group-containing monomer in the mass of the entire acrylic copolymer is preferably 3% by mass or more.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the acrylic copolymer does not include a copolymer component derived from a monomer having a carboxyl group, or includes a copolymer component derived from a monomer having a carboxyl group. And it is preferable that the ratio of the mass of the copolymer component derived from the monomer which has the said carboxyl group to the mass of the said whole acrylic copolymer is 1 mass% or less.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, it is preferable that the acrylic pressure-sensitive adhesive composition contains a pressure-sensitive adhesive auxiliary containing an oligomer having a hydrocarbon skeleton.

  In the pressure-sensitive adhesive sheet according to one aspect of the present invention, the pressure-sensitive adhesive layer is preferably composed of a silicone-based pressure-sensitive adhesive composition, and the silicone-based pressure-sensitive adhesive composition preferably includes an addition polymerization type silicone resin.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive sheet which can make resin leakage prevention property and filling property compatible at the time of sealing the semiconductor element on an adhesive sheet can be provided.

It is a section schematic diagram of the adhesive sheet concerning a first embodiment. It is a figure explaining a part of manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment. It is a figure explaining a part of manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment. It is a figure explaining a part of manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment. It is a figure explaining a part of manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment. It is a figure explaining a part of manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment. It is sectional drawing which shows the semiconductor element after the sealing process in the manufacturing process of the semiconductor device using the adhesive sheet which concerns on 1st embodiment.

[First embodiment]
[Adhesive sheet]
FIG. 1 shows a schematic cross-sectional view of the pressure-sensitive adhesive sheet 10 of the present embodiment.
The pressure-sensitive adhesive sheet 10 has a base material 11 and a pressure-sensitive adhesive layer 12 containing a pressure-sensitive adhesive composition.
The base material 11 has a first base material surface 11a and a second base material surface 11b opposite to the first base material surface 11a. In the adhesive sheet 10 of this embodiment, the adhesive layer 12 is laminated | stacked on the 1st base material surface 11a. On the pressure-sensitive adhesive layer 12, a release sheet RL is laminated as shown in FIG.
The shape of the pressure-sensitive adhesive sheet 10 can take any shape such as a tape shape and a label shape.

The pressure-sensitive adhesive sheet 10 according to the present embodiment, the surface free energy of the pressure-sensitive adhesive layer 12 is at 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, and a storage modulus at 100 ° C. of the pressure-sensitive adhesive layer 12 A (Pa ) When the thickness of the pressure-sensitive adhesive layer 12 is B (m), the numerical value calculated by the following relational expression (1) needs to be 1.5 × 10 ⁻⁵ or more.

A × B ² (1)

If the surface free energy of the pressure-sensitive adhesive layer 12 is 10 mJ / m ² or more 22 mJ / m ² or less, excellent semiconductor device on the adhesive sheet 10 to the filling of the time of sealing, sealing the semiconductor elements on the adhesive sheet 10 When stopping, the sealing resin can fill the gap between the step portion of the semiconductor element and the pressure-sensitive adhesive layer.
Moreover, when the pressure-sensitive adhesive sheet of the present embodiment is used as a support when sealing a semiconductor chip, the numerical value calculated by the relational expression (1) is 1.5 × 10 ⁻⁵ or more, Resin leakage can be prevented.

In the present specification, the surface free energy of the pressure-sensitive adhesive layer 12 can be measured by the following method. Specifically, first, the contact angles of water, diiodomethane, and 1-bromonaphthalene with respect to the pressure-sensitive adhesive layer 12 are measured using a contact angle measuring device (“DM701” manufactured by Kyowa Interface Science Co., Ltd.). The amount of each droplet is 2 μL. And surface free energy is computable from these measured values by the Kitazaki-field method.
In this specification, the storage elastic modulus of the pressure-sensitive adhesive layer is a value measured at a frequency of 1 Hz by a torsional shear method using a dynamic viscoelasticity measuring device.

In the present embodiment, the surface free energy of the pressure-sensitive adhesive layer is more preferably 12 mJ / m ² or more and 21.5 mJ / m ² or less.

In the present embodiment, from the viewpoint of filling properties, the contact angle of 1-bromonaphthalene is preferably 65 ° or more, preferably 67 ° or more, and more preferably 68 ° or more. The upper limit of the contact angle of 1-bromonaphthalene is preferably 75 ° or less, and more preferably 72 ° or less.
In addition, the following methods are mentioned as a method of adjusting the value of these surface free energy and a contact angle. For example, the values of the surface free energy and the contact angle can be adjusted by changing the composition of the pressure-sensitive adhesive composition used in the pressure-sensitive adhesive layer 12.

In this embodiment, the numerical value calculated by the relational expression (1) is preferably 2.0 × 10 ⁻⁵ or more, more preferably 5.0 × 10 ⁻⁵ or more.

The upper limit of the numerical value calculated by the relational expression (1) is not particularly limited. Since the pressure-sensitive adhesive sheet can be easily produced at low cost, it is preferably 1.0 × 10 ⁻² or less.

The pressure-sensitive adhesive sheet 10 preferably has a numerical value calculated by the following relational expression (2) of 1.5 × 10 ⁻¹⁰ or more, more preferably 5.0 × 10 ⁻¹⁰ or more, and still more preferably 1. It is 0 × 10 ⁻⁹ or more.

A × B ³ (2)

If the numerical value calculated by the relational expression (2) is 1.5 × 10 ⁻¹⁰ or more, resin leakage can be more effectively prevented.

The pressure-sensitive adhesive sheet 10 according to this embodiment preferably exhibits the following pressure-sensitive adhesive strength after heating. First, the pressure-sensitive adhesive sheet 10 is adhered to an adherend (copper foil or polyimide film), heated at 100 ° C. and 30 minutes, subsequently heated at 180 ° C. and 30 minutes, and further at 190 ° C. and 1 ° C. After heating under the conditions of time, the adhesive strength of the adhesive layer 12 to the copper foil at room temperature and the adhesive strength of the adhesive layer 12 to the polyimide film at room temperature are 0.7 N / 25 mm or more and 2.0 N / 25 mm, respectively. The following is preferable. If the adhesive strength after the above heating is 0.7 N / 25 mm or more, the adhesive sheet 10 can be prevented from peeling off from the adherend when the substrate or the adherend is deformed by heating. Moreover, if the adhesive force after performing the above-mentioned heating is 2.0 N / 25 mm or less, peeling force will not become high too much and it will be easy to peel the adhesive sheet 10 from a to-be-adhered body.
In this specification, room temperature is a temperature of 22 ° C. or higher and 24 ° C. or lower. In the present specification, the adhesive strength is a value measured by a 180 ° peeling method at a peeling speed (pulling speed) of 300 mm / min and a width of the pressure sensitive adhesive sheet of 25 mm, specifically, the method described in the examples. Measured in

(Base material)
The substrate 11 is a member that supports the pressure-sensitive adhesive layer 12.
As the base material 11, for example, a sheet material such as a synthetic resin film can be used. Examples of synthetic resin films include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film. , Polyurethane film, ethylene vinyl acetate copolymer film, ionomer resin film, ethylene / (meth) acrylic acid copolymer film, ethylene / (meth) acrylic acid ester copolymer film, polystyrene film, polycarbonate film, and polyimide film Etc. In addition, examples of the substrate 11 include these cross-linked films and laminated films.

The base material 11 preferably includes a polyester-based resin, and more preferably includes a material having a polyester-based resin as a main component. In this specification, the material having a polyester-based resin as a main component means that the proportion of the mass of the polyester-based resin in the entire material constituting the base material is 50% by mass or more. The polyester resin is, for example, any resin selected from the group consisting of polyethylene terephthalate resin, polybutylene terephthalate resin, polyethylene naphthalate resin, polybutylene naphthalate resin, and copolymer resins of these resins. Is preferred, and polyethylene terephthalate resin is more preferred.
As the base material 11, a polyethylene terephthalate film or a polyethylene naphthalate film is preferable, and a polyethylene terephthalate film is more preferable.

The lower limit of the storage elastic modulus at 100 ° C. of the substrate 11 is preferably 1 × 10 ⁷ Pa or more, more preferably 1 × 10 ⁸ Pa or more, from the viewpoint of dimensional stability during processing. The upper limit of the storage elastic modulus at 100 ° C. of the substrate 11 is preferably 1 × 10 ¹² Pa or less from the viewpoint of workability.
In addition, in this specification, the storage elastic modulus at 100 degrees C of the base material 11 is a value of the tensile elastic modulus measured at a frequency of 1 Hz using a viscoelasticity measuring device. The substrate to be measured is cut into a width of 5 mm and a length of 20 mm, and a viscoelasticity measuring device (manufactured by TA Instruments, DMAQ800) is used. Measure.

  In order to improve the adhesion between the substrate 11 and the pressure-sensitive adhesive layer 12, the first substrate surface 11a may be subjected to at least one surface treatment such as a primer treatment, a corona treatment, and a plasma treatment. Moreover, in order to improve the adhesiveness of the base material 11 and the adhesive layer 12, the adhesive material is apply | coated to the 1st base material surface 11a of the base material 11, and the preliminary adhesion process may be performed. . Examples of the pressure-sensitive adhesive used for the pressure-sensitive adhesive treatment of the substrate 11 include pressure-sensitive adhesives such as acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and urethane-based pressure-sensitive adhesives.

  The thickness of the substrate 11 is preferably 10 μm or more and 500 μm or less, more preferably 15 μm or more and 300 μm or less, and further preferably 20 μm or more and 250 μm or less.

(Adhesive layer)
The pressure-sensitive adhesive layer 12 according to this embodiment includes a pressure-sensitive adhesive composition. The pressure-sensitive adhesive contained in this pressure-sensitive adhesive composition is not particularly limited, and various types of pressure-sensitive adhesives can be applied to the pressure-sensitive adhesive layer 12. Examples of the adhesive contained in the adhesive layer 12 include a rubber adhesive, an acrylic adhesive, a silicone adhesive, a polyester adhesive, and a urethane adhesive. In addition, the kind of adhesive is selected in consideration of the use and the kind of adherend to be attached. The pressure-sensitive adhesive layer 12 is preferably made of an acrylic pressure-sensitive adhesive composition or a silicone-based pressure-sensitive adhesive composition, and more preferably made of an acrylic pressure-sensitive adhesive composition. When the pressure-sensitive adhesive layer 12 is made of an acrylic pressure-sensitive adhesive composition, the pressure-sensitive adhesive (so-called adhesive residue) remaining on the surface of the adherend when the pressure-sensitive adhesive sheet 10 is peeled from the adherend can be reduced. .

-Acrylic adhesive composition When the adhesive layer 12 consists of an acrylic adhesive composition, it is preferable that an acrylic adhesive composition contains an acrylic copolymer. In this case, the acrylic copolymer is a (meth) acrylic acid alkyl ester (CH ₂ = CR ¹ COOR ² (R ¹ is hydrogen or methyl group, R ² is linear, branched or cyclic (alicyclic)). It preferably contains a copolymer component derived from an alkyl group)). Further, from the viewpoint of adjusting the surface free energy of the pressure-sensitive adhesive layer, a part or all of the alkyl acrylate ester (CH ₂ = CR ¹ COOR ² ) has an alkyl group R ² having 6 to 8 carbon atoms (meta ) Acrylic acid alkyl ester is preferred. Examples of the (meth) acrylic acid alkyl ester in which the alkyl group R ² has 6 to 8 carbon atoms include n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth ) Isooctyl acrylate, n-octyl (meth) acrylate, and the like. Among these, it is preferred that R ² is an alkyl group of straight or branched chain. In addition, the alkyl group R ² having 8 carbon atoms is preferable, 2-ethylhexyl (meth) acrylate is more preferable, and 2-ethylhexyl acrylate is more preferable.
In the present embodiment, the acrylic copolymer preferably includes an acrylic copolymer containing 2-ethylhexyl (meth) acrylate as a main monomer.
In this specification, (meth) acrylic acid 2-ethylhexyl is the main monomer, the proportion of the mass of the copolymer component derived from (meth) acrylic acid 2-ethylhexyl occupying the total mass of the acrylic copolymer. It means 50% by mass or more.

Examples of (meth) acrylic acid alkyl ester (CH ₂ ═CR ¹ COOR ² ) having 1 to 5 or 9 to 20 carbon atoms of alkyl group R ² include, for example, methyl (meth) acrylate and (meth) acrylic. Ethyl acetate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, (meth) acrylic Examples include myristyl acid, palmityl (meth) acrylate, and stearyl (meth) acrylate.
The (meth) acrylic acid alkyl ester may be used alone or in combination of two or more.
In the present specification, “(meth) acrylic acid” is a notation used to represent both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.

In the present embodiment, the acrylic copolymer preferably contains an acrylic copolymer which said _CH ^{2 =} CR 1 COOR 2 as a main monomer.
In this specification, when CH ₂ = CR ¹ COOR ² is the main monomer, the proportion of the mass of the copolymer component derived from CH ₂ = CR ¹ COOR ² in the total mass of the acrylic copolymer is 50 masses. It means that it is more than%.
From the viewpoint of adjusting the surface free energy of the pressure-sensitive adhesive layer, the mass of the copolymer component derived from the (meth) acrylic acid alkyl ester (CH ₂ = CR ¹ COOR ² ) in the total mass of the acrylic copolymer. Is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more. The proportion of the mass of the copolymer component derived from the (meth) acrylic acid alkyl ester (CH ₂ = CR ¹ COOR ² ) is preferably 96% by mass or less from the viewpoint of improving the initial adhesion.

  When the first copolymer component in the acrylic copolymer is a (meth) acrylic acid alkyl ester, a copolymer component other than the (meth) acrylic acid alkyl ester in the acrylic copolymer (hereinafter referred to as “th” The type and number of “second copolymer component” are not particularly limited. For example, as the second copolymer component, a functional group-containing monomer having a reactive functional group is preferable. As a reactive functional group of a 2nd copolymer component, when using the crosslinking agent mentioned later, it is preferable that it is a functional group which can react with the said crosslinking agent. Examples of the reactive functional group include a carboxyl group, a hydroxyl group, an amino group, a substituted amino group, and an epoxy group.

  Examples of the monomer having a carboxyl group (hereinafter sometimes referred to as “carboxyl group-containing monomer”) include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Examples include acids. Among the carboxyl group-containing monomers, acrylic acid is preferable from the viewpoint of reactivity and copolymerization. A carboxyl group-containing monomer may be used independently and may be used in combination of 2 or more type.

  Examples of the monomer having a hydroxyl group (hereinafter sometimes referred to as “hydroxyl group-containing monomer”) include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and (meth) acrylic acid 3- (Meth) acrylic acid hydroxyalkyl esters such as hydroxypropyl, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth) acrylate is preferable from the viewpoint of hydroxyl reactivity and copolymerization. A hydroxyl-containing monomer may be used independently and may be used in combination of 2 or more type.

  Examples of the acrylic acid ester having an epoxy group include glycidyl acrylate and glycidyl methacrylate.

  As the second copolymer component in the acrylic copolymer, in addition to the above, for example, an alkoxyalkyl group-containing (meth) acrylic acid ester, a (meth) acrylic acid ester having an aromatic ring, non-crosslinkable acrylamide And a copolymer component derived from at least one monomer selected from the group consisting of (meth) acrylic acid ester having a non-crosslinkable tertiary amino group, vinyl acetate, and styrene.

Examples of the alkoxyalkyl group-containing (meth) acrylic acid ester include methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, and ethoxyethyl (meth) acrylate. It is done.
Examples of the (meth) acrylic acid ester having an aromatic ring include phenyl (meth) acrylate.
Examples of non-crosslinkable acrylamides include acrylamide and methacrylamide.
Examples of the (meth) acrylic acid ester having a non-crosslinkable tertiary amino group include (meth) acrylic acid (N, N-dimethylamino) ethyl and (meth) acrylic acid (N, N-dimethylamino). And propyl.
These monomers may be used independently and may be used in combination of 2 or more type.

In the present embodiment, the acrylic copolymer preferably includes a copolymer component derived from a monomer having a hydroxyl group.
When the acrylic copolymer contains a copolymer component derived from a monomer having a hydroxyl group, when a crosslinking agent described later is used, the crosslinking density with the hydroxyl group as a crosslinking point can be increased. This is effective in preventing chip displacement.
The ratio of the mass of the copolymer component derived from the monomer having a hydroxyl group to the total mass of the acrylic copolymer is preferably 3% by mass or more. If the proportion of the mass of the copolymer component derived from the hydroxyl group-containing monomer is 3% by mass or more, resin leakage can be more effectively prevented.
From the viewpoint of improving the filling property, the ratio of the mass of the copolymer component derived from the monomer having a hydroxyl group to the total mass of the acrylic copolymer is preferably 9.9% by mass or less.

  In the present embodiment, from the viewpoint of preventing increase in surface free energy, the acrylic copolymer preferably does not contain a copolymer component derived from a monomer having a carboxyl group. Alternatively, the acrylic copolymer includes a copolymer component derived from a monomer having a carboxyl group, and the copolymer component derived from the monomer having a carboxyl group occupies the mass of the entire acrylic copolymer. The mass ratio is preferably 1% by mass or less, and more preferably 0.05% by mass or more and 1% by mass or less.

The weight average molecular weight (Mw) of the acrylic copolymer is preferably from 300,000 to 2,000,000, more preferably from 600,000 to 1,500,000, and even more preferably from 800,000 to 1,200,000. preferable. When the weight average molecular weight Mw of the acrylic copolymer is 300,000 or more, the pressure-sensitive adhesive sheet can be peeled without a residue of pressure-sensitive adhesive on the adherend. If the weight average molecular weight Mw of an acrylic copolymer is 2 million or less, an adhesive sheet can be reliably affixed on a to-be-adhered body.
The weight average molecular weight (Mw) of the acrylic copolymer is a standard polystyrene conversion value measured by a gel permeation chromatography (GPC) method.

  The acrylic copolymer can be produced according to a conventionally known method using the various raw material monomers described above.

  The form of copolymerization of the acrylic copolymer is not particularly limited, and any of a block copolymer, a random copolymer, and a graft copolymer may be used.

  In the present embodiment, the proportion of the mass of the acrylic copolymer in the total mass of the acrylic pressure-sensitive adhesive composition is preferably 40% by mass or more and 90% by mass or less, and 50% by mass or more and 90% by mass or less. It is more preferable that

In this embodiment, when the adhesive layer 12 consists of an acrylic adhesive composition, it is preferable that an acrylic adhesive composition contains an acrylic copolymer and an adhesion aid. When the acrylic pressure-sensitive adhesive composition contains a pressure-sensitive adhesive agent, the initial tack of the pressure-sensitive adhesive sheet is improved, and peeling when the pressure-sensitive adhesive sheet is attached to the frame can be prevented.
In this embodiment, it is preferable that the adhesion promoter contained in the acrylic pressure-sensitive adhesive composition contains an oligomer having a hydrocarbon skeleton. The oligomer is preferably a polymer having a molecular weight of less than 10,000.
In addition to the above effects, the acrylic pressure-sensitive adhesive composition contains an adhesion assistant containing an oligomer having a hydrocarbon skeleton, and in addition, the increase in surface free energy can be suppressed and the filling property can be improved.
The oligomer having a hydrocarbon skeleton preferably has a reactive group. Hereinafter, the oligomer having a hydrocarbon skeleton and having a reactive group may be referred to as a hydrocarbon-based reactive adhesion aid. When the pressure-sensitive adhesive composition contains a hydrocarbon-based reactive pressure-sensitive adhesion assistant, the adhesive residue can be reduced.
In the present embodiment, the reactive group in the adhesion promoter is one or more selected from the group consisting of a hydroxyl group, an isocyanate group, an amino group, an oxirane group, an acid anhydride group, an alkoxy group, an acryloyl group, and a methacryloyl group. It is preferably a functional group, more preferably a hydroxyl group. One type or two or more types of reactive groups may be included in the adhesion aid. The adhesion promoter having a hydroxyl group may further have another reactive group described above. In addition, the number of reactive groups may be one per molecule constituting the adhesion aid, or two or more.

The oligomer having a hydrocarbon skeleton is preferably a rubber-based material from the viewpoint of reducing the surface free energy of the pressure-sensitive adhesive layer and preventing adhesive residue. The rubber-based material is not particularly limited, but a polybutadiene-based resin and a hydrogenated product of a polybutadiene-based resin are preferable, and a hydrogenated product of a polybutadiene-based resin is more preferable.
Examples of the polybutadiene-based resin include resins having 1,4-repeat units, resins having 1,2-repeat units, and resins having both 1,4-repeat units and 1,2-repeat units. The hydrogenated product of the polybutadiene resin of the present embodiment includes a hydride of a resin having these repeating units.

  When the rubber-based material has a reactive group, the polybutadiene-based resin and the hydrogenated product of the polybutadiene-based resin preferably have a reactive group at both ends. The reactive groups at both ends may be the same or different. The reactive groups at both ends are preferably one or more functional groups selected from the group consisting of a hydroxyl group, an isocyanate group, an amino group, an oxirane group, an acid anhydride group, an alkoxy group, an acryloyl group, and a methacryloyl group. More preferably, it is a hydroxyl group. In the polybutadiene resin and the hydrogenated product of the polybutadiene resin, it is more preferable that both ends are hydroxyl groups.

In this embodiment, it is also preferable that the adhesion promoter contains acetyl citrate triester. When the pressure-sensitive adhesive composition contains acetyl citrate triester, adhesive residue can be reduced.
In the present embodiment, examples of the acetylcitrate triester-based tackifier include tributyl acetylcitrate (ATBC).

The ratio of the mass of the adhesion assistant to the mass of the entire pressure-sensitive adhesive composition is preferably 3% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 30% by mass or less.
Moreover, when the adhesion assistant includes an oligomer having a hydrocarbon skeleton, the proportion of the mass of the oligomer having a hydrocarbon skeleton in the mass of the entire pressure-sensitive adhesive composition is 3% by mass or more and 50% by mass or less. Is preferable, and more preferably 5% by mass or more and 30% by mass or less.

It is also preferable that the acrylic pressure-sensitive adhesive composition according to this embodiment includes a cross-linked product obtained by cross-linking a composition containing the above-mentioned acrylic copolymer and a cross-linking agent.
In addition, the acrylic pressure-sensitive adhesive composition according to this embodiment is obtained by cross-linking a composition obtained by blending the above-mentioned acrylic copolymer, a hydrocarbon-based reactive adhesive aid, and a cross-linking agent. It is also preferable to include a product.

  In the present embodiment, examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent, an amine crosslinking agent, and an amino resin crosslinking agent. These cross-linking agents may be used alone or in combination of two or more.

In the present embodiment, from the viewpoint of improving the heat resistance and adhesive strength of the acrylic pressure-sensitive adhesive composition, among these cross-linking agents, a cross-linking agent (isocyanate-based cross-linking agent) that is a compound having an isocyanate group is preferable. Examples of the isocyanate crosslinking agent include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, Polyvalent isocyanates such as diphenylmethane-2,4′-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, dicyclohexylmethane-2,4′-diisocyanate, and lysine isocyanate Compounds.
Further, the polyvalent isocyanate compound may be a trimethylolpropane adduct type modified product of these compounds, a burette type modified product reacted with water, or an isocyanurate type modified product having an isocyanurate ring.

  In the present embodiment, the content of the crosslinking agent in the acrylic pressure-sensitive adhesive composition is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 1 part by mass with respect to 100 parts by mass of the acrylic copolymer. Part to 15 parts by mass, more preferably 5 parts to 10 parts by mass. If content of the crosslinking agent in an acrylic adhesive composition is in such a range, it will become easy to adjust the storage elastic modulus in 100 degreeC of the adhesive layer 12 to the above-mentioned range.

  In the present embodiment, from the viewpoint of heat resistance of the acrylic pressure-sensitive adhesive composition, the isocyanate-based crosslinking agent is more preferably a compound having an isocyanurate ring (isocyanurate-type modified product). The compound having an isocyanurate ring is preferably blended so that the isocyanate group is 0.7 equivalent or more and 1.5 equivalent or less with respect to the hydroxyl equivalent of the acrylic copolymer. If the compounding quantity of the compound which has an isocyanurate ring is 0.7 equivalent or more, the adhesive strength will not become too high after heating, the adhesive sheet will be easily peeled off, and the adhesive residue can be reduced. If the compounding quantity of the compound which has an isocyanurate ring is 1.5 equivalent or less, it can prevent that an initial stage adhesive force becomes low too much, or can prevent a sticking fall.

  When the acrylic adhesive composition in this embodiment contains a crosslinking agent, it is preferable that the acrylic adhesive composition further contains a crosslinking accelerator. The crosslinking accelerator is preferably selected and used as appropriate according to the type of the crosslinking agent. For example, when the acrylic pressure-sensitive adhesive composition contains a polyisocyanate compound as a cross-linking agent, it is preferable to further contain an organic metal compound-based cross-linking accelerator such as an organic tin compound.

-Silicone adhesive composition When the adhesive layer 12 consists of a silicone adhesive composition, it is preferable that a silicone adhesive composition contains a silicone resin, and it is preferable that an addition polymerization type silicone resin is included. In the present specification, a silicone pressure-sensitive adhesive composition containing an addition polymerization type silicone resin is referred to as an addition reaction type silicone pressure-sensitive adhesive composition.

In the present embodiment, the addition reaction type silicone pressure-sensitive adhesive composition contains a main agent (addition polymerization type silicone resin) and a crosslinking agent. The addition reaction type silicone pressure-sensitive adhesive composition has an advantage that it can be used only by primary curing at low temperature and does not require secondary curing at high temperature. Incidentally, the conventional peroxide curable silicone pressure-sensitive adhesive requires secondary curing at a high temperature such as 150 ° C. or higher.
Therefore, by using the addition reaction type silicone pressure-sensitive adhesive composition, it is possible to produce a pressure-sensitive adhesive sheet at a relatively low temperature, use the base material 11 having excellent energy economy and relatively low heat resistance. Thus, the pressure-sensitive adhesive sheet 10 can be manufactured. Further, since no by-product is produced during curing unlike the peroxide curable silicone pressure-sensitive adhesive, there are no problems such as odor and corrosion.

The addition reaction type silicone pressure-sensitive adhesive composition is usually composed of a main agent composed of a mixture of a silicone resin component and a silicone rubber component, a hydrosilyl group (SiH group) -containing crosslinking agent, and a curing catalyst used as necessary. Become.
The silicone resin component is an organopolysiloxane having a network structure obtained by hydrolyzing organochlorosilane or organoalkoxysilane and then performing a dehydration condensation reaction.
The silicone rubber component is a diorganopolysiloxane having a linear structure.
Examples of the organo group include, for example, a methyl group, an ethyl group, a propyl group, a butyl group, and a phenyl group, both of the silicone resin component and the silicone rubber component. The aforementioned organo groups are partially vinyl, hexenyl, allyl, butenyl, pentenyl, octenyl, (meth) acryloyl, (meth) acryloylmethyl, (meth) acryloylpropyl, and cyclohexenyl. It is substituted with an unsaturated group such as a group. An organo group having a vinyl group that is easily available industrially is preferred.
In the addition reaction type silicone-based pressure-sensitive adhesive composition, cross-linking proceeds by an addition reaction between the unsaturated group in the main agent and the hydrosilyl group in the cross-linking agent to form a network structure, thereby exhibiting adhesiveness.

  In the silicone resin component, the number of unsaturated groups such as vinyl groups is usually 0.05 or more and 3.0 or less, preferably 0.1 or more and 2.5, per 100 organo groups. It is as follows. By setting the number of unsaturated groups to 100 or more organo groups to 0.05 or more, it is possible to prevent the reactivity with the hydrosilyl group from being lowered and difficult to cure, and to impart appropriate adhesive strength. . By setting the number of unsaturated groups per 100 organo groups to 3.0 or less, the crosslinking density of the pressure-sensitive adhesive is increased, and the adhesive force and cohesive force are increased, thereby preventing adverse effects on the adherend surface.

  Specific examples of the organopolysiloxane as described above include KS-3703 manufactured by Shin-Etsu Chemical Co., Ltd. (the number of vinyl groups is 0.6 with respect to 100 methyl groups), Toray Dow BY23-753 manufactured by Corning Inc. (the number of vinyl groups is 0.1 with respect to 100 methyl groups) and BY24-162 (the number of vinyl groups is 1.4 with respect to 100 methyl groups) Etc.). In addition, SD4560PSA, SD4570PSA, SD4580PSA, SD4584PSA, SD4585PSA, SD4587L, and SD4592PSA manufactured by Toray Dow Corning Co., Ltd. can also be used.

  As described above, organopolysiloxane, which is a silicone resin component, is usually used in combination with a silicone rubber component. As the silicone rubber component, KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd. (the number of vinyl groups is methyl) is used. 7.6 for 100 groups), BY24-162 manufactured by Toray Dow Corning Co., Ltd. (for which the number of vinyl groups is 1.4 for 100 methyl groups), BY24- 843 (having no unsaturated group), SD-7292 (having 5.0 vinyl groups per 100 methyl groups), and the like.

  Specific examples of the addition polymerization type silicone resin (addition type silicone) as described above are described in, for example, JP-A-10-219229.

  The cross-linking agent usually has 0.5 to 10 hydrogen atoms bonded to silicon atoms, preferably 1 to one unsaturated group (vinyl group, etc.) of the silicone resin component and the silicone rubber component. It mix | blends so that it may become 2.5 or less. By setting the number to 0.5 or more, the reaction between the unsaturated group (vinyl group and the like) and the hydrosilyl group does not proceed completely, thereby preventing poor curing. By setting the number to 10 or less, it is possible to prevent the crosslinking agent from remaining unreacted and adversely affecting the adherend surface.

The addition reaction type silicone pressure-sensitive adhesive composition preferably contains a curing catalyst together with the aforementioned addition reaction type silicone component (main agent comprising a silicone resin component and a silicone rubber component) and a crosslinking agent.
This curing catalyst is used for promoting the hydrosilylation reaction between the unsaturated group in the silicone resin component and the silicone rubber component and the SiH group in the crosslinking agent.
The curing catalyst is a platinum-based catalyst, that is, chloroplatinic acid, an alcohol solution of chloroplatinic acid, a reaction product of chloroplatinic acid and an alcohol solution, a reaction product of chloroplatinic acid and an olefin compound, chloroplatinic acid and vinyl. Examples include a reaction product with a group-containing siloxane compound, a platinum-olefin complex, a platinum-vinyl group-containing siloxane complex, and a platinum-phosphorus complex. Specific examples of the curing catalyst as described above are described in, for example, JP-A-2006-28311 and JP-A-10-147758.
More specifically, examples of commercially available products include SRX-212 manufactured by Toray Dow Corning Co., Ltd., and PL-50T manufactured by Shin-Etsu Chemical Co., Ltd.

  When the curing catalyst is a platinum-based catalyst, the blending amount thereof is usually 5 mass ppm or more and 2000 mass ppm or less, preferably 10 mass, with respect to the total amount of the silicone resin component and the silicone rubber component as platinum content. It is mass ppm or more and 500 mass ppm or less. By setting the blending amount to 5 mass ppm or more, curability is reduced and the crosslinking density, that is, the adhesive force and cohesive force (holding force) is prevented from being decreased, and by setting it to 2000 mass ppm or less, the cost is increased. And the stability of the pressure-sensitive adhesive layer can be maintained, and the excessively used curing catalyst is prevented from adversely affecting the adherend surface.

  In the addition reaction type silicone pressure-sensitive adhesive composition, an adhesive force is exhibited even at room temperature by blending the above-mentioned components. After coating and bonding the base material 11 and the release sheet RL through the addition reaction type silicone pressure-sensitive adhesive composition, the silicone resin component and the silicone rubber component by the crosslinking agent are irradiated with heat or active energy rays. It is preferable to promote the crosslinking reaction. A pressure-sensitive adhesive sheet having a stable adhesive force can be obtained by crosslinking by irradiation with heat or active energy rays.

  When the crosslinking reaction is promoted by heating, the heating temperature is usually 60 ° C. or higher and 140 ° C. or lower, preferably 80 ° C. or higher and 130 ° C. or lower. Heating at 60 ° C. or higher prevents the silicone resin component and silicone rubber component from being insufficiently cross-linked and prevents the adhesive force from becoming insufficient. Heating at 140 ° C. or lower causes heat shrinkage to the substrate. Wrinkles can be prevented from being deteriorated or discolored.

When the active energy ray is irradiated to promote the crosslinking reaction, an active energy ray having energy quanta in an electromagnetic wave or a charged particle beam, that is, an active light such as an ultraviolet ray or an electron beam can be used. In the case of crosslinking by irradiation with an electron beam, a photopolymerization initiator is not required. However, in the case of crosslinking by irradiation with active light such as ultraviolet rays, it is preferable that a photopolymerization initiator is present.
The photopolymerization initiator in the case of crosslinking by ultraviolet irradiation is not particularly limited, and any photopolymerization initiator conventionally used in an ultraviolet curable resin is appropriately selected and used. be able to. Examples of the photopolymerization initiator include benzoins, benzophenones, acetophenones, α-hydroxy ketones, α-amino ketones, α-diketones, α-diketone dialkyl acetals, anthraquinones, thioxanthones, and other compounds. Is mentioned.
These photopolymerization initiators may be used alone or in combination of two or more. Further, the amount used is usually 0.01 parts by mass or more and 30 parts by mass or less, preferably 0.05 parts by mass with respect to 100 parts by mass of the total amount of the addition reaction type silicone component and the crosslinking agent used as the main agent. It is selected in the range of 20 parts by mass or less.

In the case of crosslinking by irradiating an electron beam which is one of the active energy rays, the acceleration voltage of the electron beam is generally 130 kV or more and 300 kV or less, preferably 150 kV or more and 250 kV or less. By irradiating with an acceleration voltage of 130 kV or more, it is possible to prevent the adhesive force from becoming insufficient due to insufficient crosslinking between the silicone resin component and the silicone rubber component. By irradiating with an acceleration voltage of 300 kV or less, It can prevent that an adhesive layer and a base material deteriorate or discolor. A preferable range of the beam current is 1 mA or more and 100 mA or less.
The dose of the irradiated electron beam is preferably 1 Mrad or more and 70 Mrad or less, and more preferably 2 Mrad or more and 20 Mrad or less. By irradiating with a dose of 1 Mrad or more, it is possible to prevent the pressure-sensitive adhesive layer and the substrate from being deteriorated or discolored, and to prevent the adhesiveness from becoming insufficient due to insufficient crosslinking. By irradiating with a dose of 70 Mrad or less, it is possible to prevent a decrease in cohesive force due to deterioration or discoloration of the pressure-sensitive adhesive layer, and it is possible to prevent the base material from being deteriorated or contracted.
The irradiation amount in the case of ultraviolet irradiation is appropriately selected. The light amount is preferably 100 mJ / cm ² or more and 500 mJ / cm ² or less, and the illuminance is preferably 10 mW / cm ² or more and 500 mW / cm ² or less.
Heating and irradiation with active energy rays are preferably performed in a nitrogen atmosphere in order to prevent reaction inhibition by oxygen.

The pressure-sensitive adhesive composition may contain other components as long as the effects of the present invention are not impaired. Examples of other components that can be included in the pressure-sensitive adhesive composition include organic solvents, flame retardants, tackifiers, ultraviolet absorbers, light stabilizers, antioxidants, antistatic agents, antiseptics, antifungal agents, and plastics. Agents, antifoaming agents, colorants, fillers, wettability adjusting agents and the like.
The addition reaction type silicone pressure-sensitive adhesive composition may contain a non-reactive polyorganosiloxane such as polydimethylsiloxane and polymethylphenylsiloxane as an additive.

More specific examples of the pressure-sensitive adhesive composition according to this embodiment include the following pressure-sensitive adhesive compositions, but the present invention is not limited to such examples.
As an example of the pressure-sensitive adhesive composition according to this embodiment, an acrylic copolymer, a pressure-sensitive adhesive aid, and a crosslinking agent are included, and the acrylic copolymer is at least 2-ethylhexyl acrylate, a carboxyl group-containing monomer. , And an acrylic copolymer obtained by copolymerizing a hydroxyl group-containing monomer, wherein the adhesion assistant contains a rubber material having a reactive group as a main component, and the crosslinking agent is an isocyanate crosslinking agent. A certain adhesive composition is mentioned.
As an example of the pressure-sensitive adhesive composition according to this embodiment, an acrylic copolymer, a pressure-sensitive adhesive aid, and a crosslinking agent are included, and the acrylic copolymer is at least 2-ethylhexyl acrylate, a carboxyl group-containing monomer. , And an acrylic copolymer obtained by copolymerizing a hydroxyl group-containing monomer, the pressure-sensitive adhesive composition is a hydroxylated hydrogenated polybutadiene at both terminals, and the crosslinking agent is an isocyanate-based crosslinking agent Is mentioned.
As an example of the pressure-sensitive adhesive composition according to this embodiment, an acrylic copolymer, an adhesion assistant, and a crosslinking agent are included, and the acrylic copolymer is at least 2-ethylhexyl acrylate, acrylic acid, and It is an acrylic copolymer obtained by copolymerizing 2-hydroxyethyl acrylate, the adhesion assistant contains a rubber material having a reactive group as a main component, and the crosslinking agent is an isocyanate crosslinking agent. And a pressure-sensitive adhesive composition.
As an example of the pressure-sensitive adhesive composition according to this embodiment, an acrylic copolymer, an adhesion assistant, and a crosslinking agent are included, and the acrylic copolymer is at least 2-ethylhexyl acrylate, acrylic acid, and A pressure-sensitive adhesive composition, which is an acrylic copolymer obtained by copolymerizing 2-hydroxyethyl acrylate, wherein the pressure-sensitive adhesive aid is a hydroxylated hydrogenated polybutadiene at both ends, and the cross-linking agent is an isocyanate-based cross-linking agent. Things.

  The thickness of the pressure-sensitive adhesive layer 12 is appropriately determined according to the use of the pressure-sensitive adhesive sheet 10. In the present embodiment, the thickness of the pressure-sensitive adhesive layer 12 is preferably 5 μm or more and 60 μm or less, and more preferably 10 μm or more and 50 μm or less. When the thickness of the pressure-sensitive adhesive layer 12 is 5 μm or more, the pressure-sensitive adhesive layer 12 easily follows the unevenness of the chip circuit surface, and the generation of a gap can be prevented. Therefore, for example, there is no possibility that the interlayer insulating material, the sealing resin, and the like enter the gaps in the irregularities on the circuit surface of the semiconductor chip, and the electrode pads for wiring connection on the chip circuit surface are blocked. When the thickness of the pressure-sensitive adhesive layer 12 is 60 μm or less, the semiconductor chip is unlikely to sink into the pressure-sensitive adhesive layer, and a step between the semiconductor chip portion and the resin portion that seals the semiconductor chip is less likely to occur. Therefore, there is no fear that the wiring is disconnected due to a step during rewiring.

(Peeling sheet)
The release sheet RL is not particularly limited. For example, from the viewpoint of ease of handling, the release sheet RL preferably includes a release substrate and a release agent layer formed by applying a release agent on the release substrate. Moreover, the release sheet RL may include a release agent layer only on one side of the release substrate, or may include a release agent layer on both sides of the release substrate.
Examples of the release substrate include a paper substrate, a laminated paper obtained by laminating a thermoplastic resin such as polyethylene on the paper substrate, and a plastic film. Examples of the paper substrate include glassine paper, coated paper, and cast coated paper. Examples of the plastic film include polyester films (for example, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate), polyolefin films (for example, polypropylene, polyethylene, and the like), and the like.
Examples of the release agent include olefin-based resins, rubber-based elastomers (for example, butadiene-based resins and isoprene-based resins), long-chain alkyl-based resins, alkyd-based resins, fluorine-based resins, and silicone-based resins. . When the pressure-sensitive adhesive layer is composed of a silicone-based pressure-sensitive adhesive composition, the release agent is preferably a non-silicone-based release agent.

The thickness of the release sheet RL is not particularly limited. The thickness of the release sheet RL is usually 20 μm or more and 200 μm or less, and preferably 25 μm or more and 150 μm or less.
The thickness of the release agent layer is not particularly limited. When a release agent layer is formed by applying a solution containing a release agent, the thickness of the release agent layer is preferably 0.01 μm or more and 2.0 μm or less, and preferably 0.03 μm or more and 1.0 μm or less. More preferred.
When a plastic film is used as the peeling substrate, the thickness of the plastic film is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 40 μm or less.

(Method for producing adhesive sheet)
The manufacturing method of the adhesive sheet 10 is not particularly limited.
For example, the adhesive sheet 10 is manufactured through the following processes.
First, the pressure-sensitive adhesive composition is applied on the first base material surface 11a of the base material 11 to form a coating film. Next, this coating film is dried to form the pressure-sensitive adhesive layer 12. Then, release sheet RL is stuck so that adhesive layer 12 may be covered.
Moreover, as another manufacturing method of the adhesive sheet 10, it manufactures through the following processes. First, an adhesive composition is applied on the release sheet RL to form a coating film. Next, the coating film is dried to form the pressure-sensitive adhesive layer 12, and the first base material surface 11 a of the base material 11 is bonded to the pressure-sensitive adhesive layer 12.

When the pressure-sensitive adhesive composition is applied to form the pressure-sensitive adhesive layer 12, it is preferable to prepare and use a coating liquid (pressure-sensitive adhesive liquid for application) by diluting the pressure-sensitive adhesive composition with an organic solvent. Examples of the organic solvent include toluene, ethyl acetate, and methyl ethyl ketone. The method for applying the coating liquid is not particularly limited. Examples of the coating method include spin coating, spray coating, bar coating, knife coating, roll knife coating, roll coating, blade coating, die coating, and gravure coating.
In order to prevent the organic solvent and the low boiling point component from remaining in the pressure-sensitive adhesive layer 12, it is preferable to apply the coating liquid to the substrate 11 or the release sheet RL, and then heat and dry the coating film.
When a crosslinking agent is blended in the pressure-sensitive adhesive composition, it is preferable to heat the coating film in order to promote the crosslinking reaction and improve the cohesive force.

(Use of adhesive sheet)
The pressure-sensitive adhesive sheet 10 is used when sealing a semiconductor element. The pressure-sensitive adhesive sheet 10 is not mounted on a metal lead frame, and is preferably used when sealing a semiconductor element that is stuck on the pressure-sensitive adhesive sheet 10. Specifically, the pressure-sensitive adhesive sheet 10 is not used when sealing a semiconductor element mounted on a metal lead frame, but seals a semiconductor element that is stuck to the pressure-sensitive adhesive layer 12. Preferably used. As a form of packaging a semiconductor element without using a metal lead frame, a panel scale package (PSP), WLP, or the like can be given.
The pressure-sensitive adhesive sheet 10 includes a step of attaching a frame member in which a plurality of openings are formed to the pressure-sensitive adhesive sheet 10; a step of attaching a semiconductor chip to the pressure-sensitive adhesive layer 12 exposed at the openings of the frame member; It is preferably used in a process having a step of covering the semiconductor chip with a sealing resin and a step of thermosetting the sealing resin.

(Method for manufacturing semiconductor device)
A method for manufacturing a semiconductor device using the pressure-sensitive adhesive sheet 10 according to this embodiment will be described.
2A to 2E are schematic views illustrating the method for manufacturing the semiconductor device according to the present embodiment.
The manufacturing method of the semiconductor device according to the present embodiment includes a step of attaching the frame member 20 in which a plurality of openings 21 are formed on the adhesive sheet 10 (adhesive sheet attaching step), and an opening 21 of the frame member 20. A step of bonding the semiconductor chip CP to the exposed adhesive layer 12 (bonding step), a step of covering the semiconductor chip CP with the sealing resin 30 (sealing step), and a step of thermosetting the sealing resin 30 ( A thermosetting step) and a step of peeling the pressure-sensitive adhesive sheet 10 (peeling step) are carried out after thermosetting. As needed, you may implement the process (reinforcing member sticking process) of sticking the reinforcement member 40 to the sealing body 50 sealed with the sealing resin 30 after the thermosetting process.
Hereinafter, each step will be described.

-Adhesive sheet sticking process The schematic explaining the process of sticking the frame member 20 to the adhesive layer 12 of the adhesive sheet 10 is shown by FIG. 2A. In addition, when the peeling sheet RL is stuck on the adhesive layer 12 of the adhesive sheet 10, the peeling sheet RL is peeled beforehand.
The frame member 20 according to the present embodiment is formed in a lattice shape and has a plurality of openings 21. The frame member 20 is preferably formed of a material having heat resistance. Examples of the material of the frame member include metals such as copper and stainless steel, and heat resistant resins such as polyimide resin and glass epoxy resin.
The opening 21 is a hole that penetrates the front and back surfaces of the frame member 20. The shape of the opening 21 is not particularly limited as long as the semiconductor chip CP can be accommodated in the frame. The depth of the hole of the opening 21 is not particularly limited as long as the semiconductor chip CP can be accommodated.

Bonding Step FIG. 2B shows a schematic diagram for explaining a step of attaching the semiconductor chip CP to the adhesive layer 12.
When the pressure-sensitive adhesive sheet 10 is adhered to the frame member 20, the pressure-sensitive adhesive layer 12 is exposed in each opening 21 according to the shape of the opening 21. The semiconductor chip CP is adhered to the adhesive layer 12 of each opening 21. The semiconductor chip CP is stuck so that its circuit surface is covered with the adhesive layer 12.

The semiconductor chip CP is manufactured, for example, by performing a back grinding process for grinding the back surface of the semiconductor wafer on which the circuit is formed and a dicing process for separating the semiconductor wafer into individual pieces. In the dicing process, a semiconductor chip CP (semiconductor element) is obtained by sticking the back surface of the semiconductor wafer to the adhesive layer of the dicing sheet and separating the semiconductor wafer using a cutting means such as a dicing saw.
The dicing apparatus is not particularly limited, and a known dicing apparatus can be used. Also, the dicing conditions are not particularly limited. Note that a laser dicing method, a stealth dicing method, or the like may be used instead of the dicing method using a dicing blade.

After the dicing process, an expanding process may be performed in which the dicing sheet is extended to widen the interval between the plurality of semiconductor chips CP. By carrying out the expanding step, the semiconductor chip CP can be picked up using a conveying means such as a collet. Further, by performing the expanding step, the adhesive force of the adhesive layer of the dicing sheet is reduced, and the semiconductor chip CP can be easily picked up.
When the energy ray polymerizable compound is blended in the adhesive composition or the adhesive layer of the dicing sheet, the energy ray polymerizable compound is applied to the adhesive layer by irradiating the adhesive layer from the substrate side of the dicing sheet. Harden. When the energy ray polymerizable compound is cured, the cohesive force of the adhesive layer is increased, and the adhesive force of the adhesive layer can be reduced. Examples of the energy rays include ultraviolet rays (UV) and electron beams (EB), and ultraviolet rays are preferable. The energy beam irradiation may be performed at any stage after the semiconductor wafer is pasted and before the semiconductor chip is peeled off (pickup). For example, the energy beam may be irradiated before or after dicing, or the energy beam may be irradiated after the expanding step.

-Sealing process and thermosetting process The schematic diagram explaining the process of sealing the semiconductor chip CP and the frame member 20 which were affixed on the adhesive sheet 10 is shown by FIG. 2C.
The material of the sealing resin 30 is a thermosetting resin, and examples thereof include an epoxy resin. The epoxy resin used as the sealing resin 30 may include, for example, a phenol resin, an elastomer, an inorganic filler, a curing accelerator, and the like.
The method for covering the semiconductor chip CP and the frame member 20 with the sealing resin 30 is not particularly limited. In the present embodiment, an embodiment using a sheet-like sealing resin 30 will be described as an example. The sheet-shaped sealing resin 30 is placed so as to cover the semiconductor chip CP and the frame member 20, and the sealing resin 30 is heated and cured to form the sealing resin layer 30A. In this way, the semiconductor chip CP and the frame member 20 are embedded in the sealing resin layer 30A. When the sheet-shaped sealing resin 30 is used, it is preferable to seal the semiconductor chip CP and the frame member 20 by a vacuum laminating method. By this vacuum laminating method, it is possible to prevent a gap from being generated between the semiconductor chip CP and the frame member 20. The temperature condition range for heat curing by the vacuum laminating method is, for example, 80 ° C. or more and 120 ° C. or less. When the sheet-shaped sealing resin 30 is used, the sheet-shaped sealing resin is solid before the sealing step. Therefore, the filling property may be inferior to using a liquid sealing resin. The adhesive sheet 10 of the present embodiment, since the surface free energy of the pressure-sensitive adhesive layer 12 is 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, even the sealing resin is a sheet-like, excellent in filling property, this step It is possible to prevent the occurrence of problems in

  In the sealing step, a laminated sheet in which the sheet-shaped sealing resin 30 is supported by a resin sheet such as polyethylene terephthalate may be used. In this case, after the laminated sheet is placed so as to cover the semiconductor chip CP and the frame member 20, the resin sheet may be peeled off from the sealing resin 30 and the sealing resin 30 may be heated and cured. Examples of such a laminated sheet include an ABF film (manufactured by Ajinomoto Fine Techno Co., Ltd.).

  As a method for sealing the semiconductor chip CP and the frame member 20, a transfer molding method may be employed. In this case, for example, the semiconductor chip CP and the frame member 20 adhered to the pressure-sensitive adhesive sheet 10 are accommodated inside the mold of the sealing device. A fluid resin material is injected into the mold to cure the resin material. In the case of the transfer mold method, the heating and pressure conditions are not particularly limited. As an example of normal conditions in the transfer mold method, a temperature of 150 ° C. or higher and a pressure of 4 MPa to 15 MPa are maintained for 30 seconds to 300 seconds. Thereafter, the pressure is released, the cured product is taken out from the sealing device, and left in an oven, and a temperature of 150 ° C. or higher is maintained for 2 hours to 15 hours. In this way, the semiconductor chip CP and the frame member 20 are sealed.

  When using the sheet-like sealing resin 30 in the above-mentioned sealing process, you may implement a 1st heat press process before the process (thermosetting process) of thermosetting the sealing resin 30. FIG. In the first heating press step, the semiconductor chip CP and the pressure-sensitive adhesive sheet 10 with the frame member 20 covered with the sealing resin 30 are sandwiched by plate members from both sides, and pressed under conditions of a predetermined temperature, time, and pressure. . By performing the first heat pressing step, the sealing resin 30 is easily filled into the gap between the semiconductor chip CP and the frame member 20. Moreover, the unevenness | corrugation of 30 A of sealing resin layers comprised with the sealing resin 30 can also be planarized by implementing a heat press process. As the plate member, for example, a metal plate such as stainless steel can be used.

  When the pressure-sensitive adhesive sheet 10 is peeled after the thermosetting step, the semiconductor chip CP and the frame member 20 sealed with the sealing resin 30 are obtained. Hereinafter, this may be referred to as a sealing body 50.

-Reinforcing member sticking process The schematic diagram explaining the process of sticking the reinforcing member 40 to the sealing body 50 is shown by FIG. 2D.
After the adhesive sheet 10 is peeled off, a rewiring process and a bumping process for forming a rewiring layer on the exposed circuit surface of the semiconductor chip CP are performed.
In order to improve the handleability of the sealing body 50 in such a rewiring process and a bumping process, a process (reinforcing member attaching process) of attaching the reinforcing member 40 to the sealing body 50 is performed as necessary. May be. When implementing a reinforcement member sticking process, it is preferable to carry out before peeling the adhesive sheet 10. FIG. As illustrated in FIG. 2D, the sealing body 50 is supported in a state of being sandwiched between the adhesive sheet 10 and the reinforcing member 40.

In the present embodiment, the reinforcing member 40 includes a heat-resistant reinforcing plate 41 and a heat-resistant adhesive layer 42.
Examples of the reinforcing plate 41 include a plate-like member containing a heat resistant resin such as a polyimide resin and a glass epoxy resin.
The adhesive layer 42 adheres the reinforcing plate 41 and the sealing body 50. The adhesive layer 42 is appropriately selected according to the material of the reinforcing plate 41 and the sealing resin layer 30A. For example, when the sealing resin layer 30A includes an epoxy resin and the reinforcing plate 41 includes a glass epoxy resin, the adhesive layer 42 is preferably a glass cloth including a thermoplastic resin. As the thermoplastic resin contained, bismaleimide triazine resin (BT resin) is preferable.

  In the reinforcing member sticking step, the adhesive layer 42 is sandwiched between the sealing resin layer 30A of the sealing body 50 and the reinforcing plate 41, and is further sandwiched between the reinforcing plate 41 side and the adhesive sheet 10 side by plate members, respectively. It is preferable to carry out the second hot pressing step of pressing under the conditions of temperature, time and pressure. The sealing body 50 and the reinforcing member 40 are temporarily fixed by the second heating press process. In order to cure the adhesive layer 42 after the second heat pressing step, it is preferable to heat the temporarily fixed sealing body 50 and the reinforcing member 40 under conditions of a predetermined temperature and time. The conditions for heat curing are appropriately set according to the material of the adhesive layer 42, and are, for example, 185 ° C., 80 minutes, and 2.4 MPa. Also in the second heat pressing step, as the plate-like member, for example, a metal plate such as stainless steel can be used.

-Peeling process The schematic explaining the process of peeling the adhesive sheet 10 is shown by FIG. 2E.
In this embodiment, since the base material 11 of the adhesive sheet 10 can be bent, it can be easily peeled from the frame member 20, the semiconductor chip CP, and the sealing resin layer 30A while the adhesive sheet 10 is bent. Although peeling angle (theta) is not specifically limited, It is preferable to peel the adhesive sheet 10 with peeling angle (theta) of 90 degree | times or more. When the peeling angle θ is 90 degrees or more, the pressure-sensitive adhesive sheet 10 can be easily peeled from the frame member 20, the semiconductor chip CP, and the sealing resin layer 30A. The peeling angle θ is preferably 90 degrees or more and 180 degrees or less, and more preferably 135 degrees or more and 180 degrees or less. By peeling the adhesive sheet 10 while bending the adhesive sheet 10 in this way, the peeling can be performed while reducing the load applied to the frame member 20, the semiconductor chip CP, and the sealing resin layer 30A. Damage to the chip CP and the sealing resin layer 30A can be suppressed. The temperature atmosphere at the time of peeling the pressure-sensitive adhesive sheet 10 may be room temperature, but when there is a concern about the destruction of each member of the adherend and the interface between the members at the time of peeling, the pressure-sensitive adhesive of the pressure-sensitive adhesive For the purpose of lowering, the pressure-sensitive adhesive sheet 10 may be peeled in a temperature atmosphere higher than room temperature. As temperature atmosphere higher than room temperature, the range of 30-60 degreeC is preferable, and the range of 35-50 degreeC is more preferable. After the pressure-sensitive adhesive sheet 10 is peeled off, the above-described rewiring process and bumping process are performed. After the pressure-sensitive adhesive sheet 10 is peeled off, before the rewiring step and the bumping step, etc., the aforementioned reinforcing member sticking step may be performed as necessary.

When the reinforcing member 40 is attached, the reinforcing member 40 is peeled off from the sealing body 50 at the stage where the support by the reinforcing member 40 becomes unnecessary after the rewiring process and the bumping process are performed.
Thereafter, the sealing body 50 is separated into individual semiconductor chips CP (individualization step). A method for dividing the sealing body 50 into individual pieces is not particularly limited. For example, the semiconductor wafer can be separated into pieces by the same method as that used when dicing the semiconductor wafer. The step of dividing the sealing body 50 into pieces may be performed in a state where the sealing body 50 is adhered to a dicing sheet or the like. By separating the sealing body 50 into individual pieces, a semiconductor package in units of the semiconductor chip CP is manufactured, and this semiconductor package is mounted on a printed wiring board or the like in a mounting process.

According to this embodiment, the adhesive sheet 10 can prevent resin leakage when sealing the semiconductor element on the adhesive sheet and has good filling properties when sealing the semiconductor element on the adhesive sheet. Can provide. Moreover, according to the manufacturing method of the semiconductor device using the adhesive sheet 10 of this embodiment, resin leakage can be prevented and the chip can be prevented from flowing or floating. Therefore, the yield of semiconductor devices is improved.
Moreover, according to the manufacturing method of the semiconductor device using the adhesive sheet 10 of the present embodiment, in the sealing process, as shown in FIG. 3, the sealing resin 30 is formed on the peripheral portion of the circuit surface CPA of the semiconductor chip CP. A gap S between a certain stepped portion CPB and the pressure-sensitive adhesive layer 12 can be embedded.
The height dimension x of the step between the step portion CPB and the circuit surface CPA is usually 0.1 μm or more and 10 μm or less, preferably 0.5 μm or more and 5 μm or less. As the height dimension x is smaller, the sealing resin 30 is less likely to fill the gap S. However, if the height dimension x is equal to or greater than the lower limit, the sealing resin 30 can fill the gap S.
The width dimension y of the stepped portion CPB is usually 1 μm or more and 100 μm or less, and preferably 5 μm or more and 50 μm or less. The larger the width dimension y, the harder the sealing resin 30 fills the gap S. However, the sealing resin 30 can embed the gap S as long as the upper limit is not reached.

[Modification of Embodiment]
The present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. In the following description, if it is the same as the member described in the above embodiment, the same reference numeral is given and the description is omitted or simplified.

In the said embodiment, although the aspect in which the adhesive layer 12 of the adhesive sheet 10 was covered with the peeling sheet RL was mentioned as an example, this invention is not limited to such an aspect.
Moreover, the adhesive sheet 10 may be a sheet piece, and may be provided in a state in which a plurality of adhesive sheets 10 are laminated. In this case, for example, the pressure-sensitive adhesive layer 12 may be covered with the base material 11 of another pressure-sensitive adhesive sheet to be laminated.
Further, the pressure-sensitive adhesive sheet 10 may be a belt-like sheet or may be provided in a state of being wound in a roll shape. The pressure-sensitive adhesive sheet 10 wound up in a roll shape can be used by being unwound from a roll and cut into a desired size.

  In the said embodiment, although the case where the material of the sealing resin 30 was a thermosetting resin was mentioned as an example and demonstrated, this invention is not limited to such an aspect. For example, the sealing resin 30 may be an energy ray curable resin that is cured by energy rays such as ultraviolet rays.

  In the above-described embodiment, all the steps in the semiconductor device manufacturing method do not necessarily have to be performed, and some steps may be omitted.

  In the said embodiment, in the description of the manufacturing method of a semiconductor device, the aspect which sticks the frame member 20 to the adhesive sheet 10 was mentioned as an example, However, This invention is not limited to such an aspect. The adhesive sheet 10 may be used in a method for manufacturing a semiconductor device that seals a semiconductor element without using a frame member.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples.

〔Evaluation method〕
Evaluation of the pressure-sensitive adhesive sheet was performed according to the following method.
[Storage modulus]
The coating adhesive solution in Example 1 was applied to a release film (“PET3801”, manufactured by Lintec Corporation) using a comma coater (registered trademark), and then dried (drying conditions: 90 ° C., 90 seconds, and 115 ° C., 90 seconds), a layer having a thickness of 30 μm was formed, and this was laminated to produce a circular measurement sample having a thickness of 1 mm and a diameter of 8 mm. The storage elastic modulus (Pa) at 100 ° C. of the obtained measurement sample was measured by a torsional shear method using a viscoelasticity measuring device (MCR manufactured by Anton Paar Japan). The heating rate was 5 ° C./min, and the measurement frequency was 1 Hz.
Using the adhesive liquids for coating in Examples 2 to 5 and Comparative Examples 1 to 3, the storage elastic modulus (Pa) at 100 ° C. of the obtained measurement samples was measured in the same manner as described above.

[Adhesive force]
The pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet produced in Example 1 was applied to an adherend (polyimide film) with a load of 2 kgf. As the polyimide film, Kapton 100H (product name) having a thickness of 25 μm manufactured by Toray DuPont Co., Ltd. was used. This polyimide film-attached pressure-sensitive adhesive sheet is stored for 0.5 hours in an environment of 25 ° C. and 50% relative humidity, and then using a thermostat (manufactured by ESPEC Corporation, PHH-202) under the conditions of 190 ° C. and 1 hour. After heating, the pressure-sensitive adhesive sheet with a polyimide film was stored for 1 hour in an environment of 25 ° C. and 50% relative humidity. Thereafter, the adhesive strength of the adhesive sheet was measured by a 180 ° peeling method in an environment of 25 ° C. and 50% relative humidity. In addition, as a measuring device, a measuring device with a thermostatic bath (manufactured by A & D, TENSILON) was used, the tensile speed was 300 mm / min, and the width of the adhesive sheet was 25 mm.
About the adhesive sheet produced in Examples 2-5 and Comparative Examples 1-3, the adhesive force of the adhesive sheet was measured similarly to the above.

[Resin leakage prevention]
8000 silicon chips (2.3 mm × 1.7 mm × 0.2 mm thickness) that have been mirror-finished on the adhesive surface of the adhesive sheet prepared in Example 1 are 80 rows and 100 columns so that the mirror-finished surface is in contact. Was installed. At this time, the direction parallel to the 2.3 mm long side of the chip was aligned with the column direction of the chip array. Further, the distance between adjacent chips was set such that the distance between the centers of the rectangular shapes of the chips was 5 mm. The chip on the adhesive sheet was sealed with an interlayer insulating resin (Ajinomoto Fine Chemical ABF; T-15B) using a vacuum heating and pressure laminator (ROHM and HAAS, 7024HP5). Sealing conditions were such that the preheating temperature of the vacuum heating and pressurization laminator table and the diaphragm was 100 ° C., and the sealing was performed for 60 seconds by vacuuming, 30 seconds in the Dynamic press mode, and 10 seconds in the Static press mode. .
After that, the state of the interface between the chip and the pressure-sensitive adhesive sheet is confirmed with a digital microscope through the pressure-sensitive adhesive sheet. If the interlayer insulating resin penetrates 10 μm or more from the end of the chip between the chip and the pressure-sensitive adhesive sheet, there is a resin leak. Less than the case was regarded as no resin leakage.
About the adhesive sheet produced in Examples 2-5 and Comparative Examples 1-3, resin leak prevention property was evaluated similarly to the above.

[Surface free energy and contact angle]
The surface free energy of the pressure-sensitive adhesive layer was measured by the following method. Specifically, first, using a contact angle measuring device (“DM701” manufactured by Kyowa Interface Chemical Co., Ltd.), the contact angles of water, diiodomethane and 1-bromonaphthalene to the pressure-sensitive adhesive layer produced in Example 1 were measured. did. The amount of each droplet was 2 μL. And the surface free energy was computed from these measured values by the Kitazaki-field method.
For the pressure-sensitive adhesive layers prepared in Examples 2 to 5 and Comparative Examples 1 to 3, the contact angle was measured in the same manner as described above, and the surface free energy was calculated from these measured values.

[Filling property evaluation]
Semiconductor chip (silicon chip with mirror finish, chip size: 2.3 mm × 1.7 mm, chip thickness: 0.2 mm, level difference between the stepped portion and the circuit surface on the pressure-sensitive adhesive surface of the pressure-sensitive adhesive sheet produced in Example 1 The height dimension x: 1 μm, the width dimension y of the stepped part: 30 μm (manufactured by ULVAC, Inc., measured with Dektak 150)) 80 pieces so that the adhesive surface of the adhesive sheet and the circuit surface of the semiconductor chip are in contact with each other. Installed in an arrangement of 100 rows and 100 columns. At this time, the direction parallel to the 2.3 mm long side of the chip was aligned with the column direction of the chip array. Further, the distance between adjacent chips was set such that the distance between the centers of the rectangular shapes of the chips was 5 mm. Then, the semiconductor chip on the adhesive sheet is sealed with a sealing resin (ABF film manufactured by Ajinomoto Fine Techno Co., Ltd., GX LE-T15B) using a vacuum heating and pressure laminator (“7024HP5” manufactured by ROHM and HAAS). (Sealing process). The sealing conditions are as follows.
-Preheating temperature: 100 ° C for both table and diaphragm
・ Vacuum evacuation: 60 seconds ・ Dynamic press mode: 30 seconds ・ Static press mode: 10 seconds Then, the semiconductor chips on the pressure-sensitive adhesive sheet after the sealing process are observed with a microscope (the entire circumference of each semiconductor chip), and the semiconductor It was confirmed whether or not the sealing resin was embedded in the gap between the step portion of the chip and the adhesive layer. The case where the sealing resin was embedded in the gap was determined as “A”, and the case where the sealing resin was not embedded in the gap or a void was generated in the gap was determined as “B”.
About the adhesive sheet produced in Examples 2-5 and Comparative Examples 1-3, filling property was evaluated similarly to the above.

[Preparation of adhesive sheet]
Example 1
(1) Preparation of pressure-sensitive adhesive composition The following materials (polymer, pressure-sensitive adhesive, cross-linking agent, and diluting solvent) were blended and sufficiently stirred, and the pressure-sensitive adhesive liquid for coating according to Example 1 (pressure-sensitive adhesive composition) Prepared).
-Polymer: Acrylic ester copolymer, 40 parts by mass (solid content)
The acrylic ester copolymer was prepared by copolymerizing 92.8% by mass of 2-ethylhexyl acrylate, 7.0% by mass of 2-hydroxyethyl acrylate, and 0.2% by mass of acrylic acid. The weight average molecular weight of the obtained polymer was 850,000.
-Adhesion aid: hydroxylated hydrogenated polybutadiene at both ends [manufactured by Nippon Soda Co., Ltd .; GI-1000], 5 parts by mass (solid content)
Crosslinking agent: Aliphatic isocyanate having hexamethylene diisocyanate (isocyanurate-type modified product of hexamethylene diisocyanate) [manufactured by Nippon Polyurethane Industry Co., Ltd .; Coronate HX], 3.5 parts by mass (solid content)
Diluting solvent: Methyl ethyl ketone was used, and the solid content concentration of the coating adhesive solution was adjusted to 30% by mass.

(2) Preparation of pressure-sensitive adhesive layer The prepared pressure-sensitive adhesive liquid was applied to the release layer surface side of a release film [manufactured by Lintec Corporation; SP-PET382150] made of a 38 μm transparent polyethylene terephthalate film provided with a silicone release layer. Application was performed using a comma coater (registered trademark), heating was performed at 90 ° C. and 90 seconds, followed by heating at 115 ° C. and 90 seconds, and the coating film was dried to prepare an adhesive layer. The thickness of the pressure-sensitive adhesive layer was 50 μm.

(3) Preparation of pressure-sensitive adhesive sheet After the coating film of the pressure-sensitive adhesive liquid for application was dried, the pressure-sensitive adhesive layer and the substrate were bonded together to obtain a pressure-sensitive adhesive sheet according to Example 1. A transparent polyethylene terephthalate film [manufactured by Teijin DuPont Films; PET 50KFL12D, thickness 50 μm, storage elastic modulus 3.1 × 10 ⁹ Pa at 100 ° C.] is used as the base material, and an adhesive is applied to one surface of the base material. The layers were laminated.

(Example 2)
(1) Preparation of pressure-sensitive adhesive composition In Example 2, a silicone-based pressure-sensitive adhesive was used.
In Example 2,
Silicone-based adhesive A (SD4580PSA) 18 parts by mass (solid content)
40 parts by mass (solid content) of silicone-based pressure-sensitive adhesive B (SD-4487L),
0.3 part by mass (solid content) of catalyst A (NC-25CAT),
Catalyst B (CAT-SRX-212) 0.65 parts by mass (solid content) and Silicone dispersion (BY-24-712) 5 parts by mass (solid content)
Was mixed with toluene as a diluent solvent so that the solid content was 20% by mass and stirred sufficiently to prepare a coating pressure-sensitive adhesive liquid (pressure-sensitive adhesive composition) according to Example 2. The materials used for the pressure-sensitive adhesive composition of Example 2 are all manufactured by Toray Dow Corning Co., Ltd.

(2) Preparation of pressure-sensitive adhesive sheet Implemented on one side of a polyimide film as a base material [manufactured by Toray DuPont Co., Ltd .; Kapton 100H, thickness 25 μm, storage elastic modulus 3.1 × 10 ⁹ Pa at 100 ° C.] It is carried out by applying the pressure-sensitive adhesive liquid for application according to Example 2 using a comma coater (registered trademark), heating at 130 ° C. for 2 minutes, drying the coating film, and preparing a pressure-sensitive adhesive layer. A pressure-sensitive adhesive sheet according to Example 2 was obtained. The thickness of the pressure-sensitive adhesive layer was 20 μm.

(Example 3)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer after drying the pressure-sensitive adhesive liquid for coating was 30 μm.

Example 4
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer after drying of the pressure-sensitive adhesive liquid for coating was 40 μm.

(Example 5)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer after drying the pressure-sensitive adhesive liquid for coating was 50 μm.

(Comparative Example 1)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Example 2 except that the thickness of the pressure-sensitive adhesive layer after drying the pressure-sensitive adhesive liquid for coating was 10 μm.

(Comparative Example 2)
A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the polymer of Example 1 was changed to the following composition.
The acrylic ester copolymer comprises a copolymer of 80.8% by mass of 2-ethylhexyl acrylate, 12% by mass of acryloylmorpholine, 7.0% by mass of 2-hydroxyethyl acrylate, and 0.2% by mass of acrylic acid. Prepared by polymerization. The weight average molecular weight of the obtained polymer was 760,000.

(Comparative Example 3)
A pressure-sensitive adhesive sheet was prepared in the same manner as in Comparative Example 2 except that the thickness of the pressure-sensitive adhesive in Comparative Example 2 was changed to 20 μm.

  In Table 1, the evaluation result of the adhesive sheet which concerns on Examples 1-5 and Comparative Examples 1-3 is shown.

As shown in Table 1, the pressure-sensitive adhesive sheets according to Examples 1 to 5, numbers surface free energy of the pressure-sensitive adhesive layer is 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, and is calculated by A × ^{B 2} Is 1.5 × 10 ⁻⁵ or more, it was confirmed that the filling property is good and the resin leakage can be prevented.
On the other hand, the pressure-sensitive adhesive sheet according to Comparative Example 1 has a numerical value calculated by A × B ² of less than 1.5 × 10 ⁻⁵ , so it is considered that resin leakage could not be prevented. Moreover, since the surface free energy of an adhesive layer is over 22 mJ / m < ² >, the adhesive sheet which concerns on Comparative Examples 2-3 is considered to be inferior to the filling property at the time of sealing the semiconductor element on an adhesive sheet. .

DESCRIPTION OF SYMBOLS 10 ... Adhesive sheet, 11 ... Base material, 12 ... Adhesive layer, 20 ... Frame member, 21 ... Opening part.

Claims (14)

A pressure-sensitive adhesive sheet used when sealing a semiconductor element on a pressure-sensitive adhesive sheet,
The pressure-sensitive adhesive sheet comprises a substrate and a pressure-sensitive adhesive layer containing a pressure-sensitive adhesive composition,
The surface free energy of the pressure-sensitive adhesive layer has a 10 mJ / ^{m 2} or more 22 mJ / ^{m 2} or less, and,
When the storage elastic modulus at 100 ° C. of the pressure-sensitive adhesive layer is A (Pa) and the thickness of the pressure-sensitive adhesive layer is B (m), the numerical value calculated by the following relational expression (1) is 1.5 × 10 ^{− 5} or more
Adhesive sheet.
A × B ² (1) The contact angle of 1-bromonaphthalene to the pressure-sensitive adhesive layer is 65 ° or more,
The pressure-sensitive adhesive sheet according to claim 1. The numerical value calculated by the following relational expression (2) is 1.5 × 10 ⁻¹⁰ or more,
The pressure-sensitive adhesive sheet according to claim 1 or claim 2.
A × B ³ (2) The storage elastic modulus at 100 ° C. of the substrate is 1 × 10 ⁷ Pa or more.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 3. The pressure-sensitive adhesive layer comprises an acrylic pressure-sensitive adhesive composition or a silicone-based pressure-sensitive adhesive composition.
The pressure-sensitive adhesive sheet according to any one of claims 1 to 4. The pressure-sensitive adhesive layer is made of an acrylic pressure-sensitive adhesive composition,
The acrylic pressure-sensitive adhesive composition contains an acrylic copolymer,
The pressure-sensitive adhesive sheet according to claim 5. The proportion of the mass of the copolymer component derived from the (meth) acrylic acid alkyl ester in the total mass of the acrylic copolymer is 90% by mass or more.
The pressure-sensitive adhesive sheet according to claim 6. The carbon number of alkyl in the (meth) acrylic acid alkyl ester is 6 to 8,
The pressure-sensitive adhesive sheet according to claim 7. The acrylic copolymer includes an acrylic copolymer mainly composed of 2-ethylhexyl (meth) acrylate.
The pressure-sensitive adhesive sheet according to any one of claims 6 to 8. The acrylic copolymer includes a copolymer component derived from a monomer having a hydroxyl group.
The pressure-sensitive adhesive sheet according to any one of claims 6 to 9. The proportion of the mass of the copolymer component derived from the monomer having a hydroxyl group in the total mass of the acrylic copolymer is 3% by mass or more.
The pressure-sensitive adhesive sheet according to claim 10. The acrylic copolymer is
It does not contain a copolymer component derived from a monomer having a carboxyl group, or contains a copolymer component derived from a monomer having a carboxyl group, and occupies the total mass of the acrylic copolymer. The proportion of the mass of the copolymer component derived from the monomer having is 1% by mass or less,
The pressure-sensitive adhesive sheet according to any one of claims 6 to 11. The acrylic pressure-sensitive adhesive composition contains a pressure-sensitive adhesive agent including an oligomer having a hydrocarbon skeleton,
The pressure-sensitive adhesive sheet according to any one of claims 6 to 12. The pressure-sensitive adhesive layer is composed of a silicone-based pressure-sensitive adhesive composition, and the silicone-based pressure-sensitive adhesive composition includes an addition polymerization type silicone resin.
The pressure-sensitive adhesive sheet according to claim 5.

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