CN113165349A

CN113165349A - Film-like adhesive, laminate sheet, composite sheet, and method for producing laminate

Info

Publication number: CN113165349A
Application number: CN201980079178.0A
Authority: CN
Inventors: 佐藤阳辅
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2018-12-28
Filing date: 2019-12-23
Publication date: 2021-07-23
Also published as: TWI832944B; TW202039751A; KR20210110571A; JPWO2020137947A1; WO2020137947A1

Abstract

The film-like adhesive of the present embodiment is used for bonding a circuit-forming surface of a chip and a light-transmissive cover, and at least one surface of the film-like adhesive is substantially free of an aromatic compound.

Description

Film-like adhesive, laminate sheet, composite sheet, and method for producing laminate

Technical Field

The present invention relates to a film-like adhesive, a laminate sheet, a composite sheet, and a method for producing a laminate.

The present application claims priority based on japanese patent application No. 2018-246839 filed in japan on 28/12/2018, and the contents thereof are incorporated herein.

Background

In manufacturing or processing various members constituting an electronic device, various film-like adhesives can be used according to the purpose.

For example, when a semiconductor chip is mounted on a circuit forming surface of a substrate, a film-like adhesive is attached to a back surface of the semiconductor chip in advance, and the semiconductor chip is bonded (die-bonded) to the circuit forming surface of the substrate via the film-like adhesive. In addition, when protecting a circuit forming surface of a chip such as a sensor, the circuit forming surface is covered with a light-transmitting cover (cover) via a film-like adhesive having light-transmitting properties.

On the other hand, a member including the film-shaped adhesive may be exposed to a high temperature in a heating step such as a reflow step. In this case, the deterioration of the film-like adhesive due to the influence of heat may be a problem. For example, if a film-shaped adhesive having light transmittance is discolored, it becomes difficult to read information through the film-shaped adhesive. The film-like adhesive contains a resin component to exhibit adhesiveness, and contains a thermosetting component to impart thermosetting property depending on the case, but these components are unstable to heat. That is, conventional film-like adhesives are easily discolored by heating.

As a film-shaped adhesive having light transmittance, for example, a die bond film having light transmittance of 80% or more at a wavelength of 1065nm is disclosed, which is used for die bonding of semiconductor chips (see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6310748

Disclosure of Invention

Technical problem to be solved by the invention

However, patent document 1 does not disclose physical properties after heating such as color of the solid crystal film after heating.

The purpose of the present invention is to provide a film-shaped adhesive that has optical transparency before and after heating and is inhibited from coloring after heating, a laminate sheet and a composite sheet using the film-shaped adhesive, and a method for producing a laminate using the film-shaped adhesive.

Means for solving the problems

The present invention provides a film-like adhesive used for bonding a circuit-forming surface of a chip and a light-transmitting cover, at least one surface of the film-like adhesive being substantially free of aromatic compounds.

In the film-shaped adhesive of the present invention, the linear transmittance of the film-shaped adhesive to light having a wavelength of 400 to 800nm may be 90% or more before heating at 260 ℃, the linear transmittance of the film-shaped adhesive to light having a wavelength of 400 to 800nm may be 85% or more after heating at 260 ℃ for 10 minutes, and the thickness of the film-shaped adhesive may be 10 to 40 μm.

The film-like adhesive of the present invention preferably contains an aliphatic epoxy compound.

The film-like adhesive of the present invention may contain an aliphatic phosphite as an antioxidant.

In the film-shaped adhesive of the present invention, the film-shaped adhesive may contain an acrylic resin and an aliphatic polyisocyanate-based crosslinking agent, and the acrylic resin may have a functional group capable of bonding to the crosslinking agent.

The present invention provides a laminate sheet comprising the film-like adhesive and a resin film provided on one surface of the film-like adhesive.

The present invention provides a composite sheet comprising the film-shaped adhesive and a dicing sheet provided on one surface of the film-shaped adhesive, wherein the dicing sheet comprises a base material and an adhesive layer provided on one surface of the base material, and the adhesive layer is disposed between the base material and the film-shaped adhesive.

The present invention provides a method for manufacturing a laminate, wherein a circuit forming surface of a chip is bonded to one surface of the film-shaped adhesive, and a light-transmitting cover is bonded to the other surface of the film-shaped adhesive, thereby obtaining a laminate in which the chip, the film-shaped adhesive, and the light-transmitting cover are sequentially laminated.

Effects of the invention

The film-like adhesive of the present invention has light transmittance before and after heating, and is inhibited from being colored after heating.

By using the laminate sheet or composite sheet of the present invention provided with the film-shaped adhesive of the present invention, the film-shaped adhesive can be provided to a member to which the film-shaped adhesive is applied.

The method for producing a laminate of the present invention can produce a laminate in which a chip, a film-like adhesive, and a light-transmissive cover are sequentially laminated.

Drawings

Fig. 1 is a sectional view schematically showing an example of a film-like adhesive and a laminate sheet according to an embodiment of the present invention.

Figure 2 is a cross-sectional view schematically showing another example of a laminate sheet according to an embodiment of the present invention.

Fig. 3 is a sectional view schematically showing an example of a composite sheet according to an embodiment of the present invention.

Fig. 4 is a cross-sectional view schematically showing an example of a laminate manufactured using the film-like adhesive according to an embodiment of the present invention.

Fig. 5 is a sectional view for schematically illustrating one example of a using method of the composite sheet according to one embodiment of the present invention.

FIG. 6 shows the FT-IR measurement results of the film-shaped adhesives of examples and comparative examples.

Detailed Description

Film-like adhesive

The film-like adhesive according to one embodiment of the present invention is a film-like adhesive used for bonding a circuit-forming surface of a chip and a light-transmissive cover, and at least one surface of the film-like adhesive is substantially free of an aromatic compound.

The film-like adhesive satisfying the above conditions is suppressed in clouding and coloring before and after heating at 260 ℃ or the like, and has high linear transmittance of light having a wavelength of 400 to 800nm (in the present specification, sometimes abbreviated as "light (400 to 800 nm)").

The film-like adhesive of the present embodiment can be used for adhesion of an object when manufacturing or processing various members constituting an electronic device.

For example, the circuit formation surface of a chip such as a sensor may be covered with a light-transmissive cover (protective cover) via the film-like adhesive. That is, the film-like adhesive can be used as a film for adhering the cover to the circuit forming surface of the chip.

In this case, since the film-like adhesive has high light transmittance before and after heating and is suppressed from being colored as described above, it is possible to recognize visual information existing on the circuit formation surface of the chip stably and with high accuracy through the light-transmissive cover and the film-like adhesive.

As a sensor to be covered with the light-transmitting cover (protective cover), for example, a fingerprint sensor can be mentioned. However, this is only one example of a sensor.

In this specification, the surface of the substrate and the chip on which the circuit is formed is referred to as a "circuit-formed surface".

In the present specification, the term "chip" is used to include not only a semiconductor chip but also chips other than a semiconductor chip.

The film-like adhesive of the present embodiment preferably has thermosetting properties, and preferably has pressure-sensitive adhesiveness. For example, a film-like adhesive having both thermosetting and pressure-sensitive adhesiveness can be attached to various adherends by lightly pressing in an uncured state. Further, the film-like adhesive can be attached to various adherends by heating and softening. The film-like adhesive is cured to finally form a cured product having high impact resistance, and the cured product can maintain sufficient adhesive properties even under severe conditions of high temperature and high humidity.

The linear transmittance of the film-like adhesive of the present embodiment to light (400 to 800nm) (which may be abbreviated as "linear transmittance before heating" in the present specification) is preferably 90% or more, more preferably 91.5% or more, further preferably 93% or more, and particularly preferably 94.5% or more before heating at 260 ℃. When the linear transmittance before heating is not less than the lower limit value, the film-shaped adhesive before heating has a high property of being able to accurately recognize an image when the image is observed through the film-shaped adhesive (in this specification, this may be abbreviated as "image visibility").

The upper limit of the linear transmittance of light (400 to 800nm) before heating is not particularly limited, and may be 100%.

For example, the film-like adhesive having a linear transmittance of 99.8% or less before heating can be produced more easily.

The linear transmittance of light (400 to 800nm) before heating can be appropriately adjusted within a range set by arbitrarily combining any of the lower limit values and the upper limit values. For example, in one embodiment, the linear transmittance before heating is preferably 90 to 99.8%, more preferably 91.5 to 99.8%, further preferably 93 to 99.8%, and particularly preferably 94.5 to 99.8%. However, these ranges are only one example of the linear transmittance before heating.

The linear transmittance of the film-like adhesive of the present embodiment to light (400 to 800nm) (in the present specification, may be abbreviated as "linear transmittance after heating") after heating at 260 ℃ for 10 minutes is preferably 85% or more, and may be, for example, any range of 87.5% or more, 90% or more, and 94% or more. When the linear transmittance after heating is not less than the lower limit value, the image visibility of the film-shaped adhesive after heating is high.

The upper limit of the linear transmittance of light (400 to 800nm) after heating is not particularly limited, and may be 100%.

For example, the film-like adhesive having a linear transmittance of 99.8% or less after heating can be produced more easily.

The linear transmittance of light (400 to 800nm) after heating can be appropriately adjusted within a range set by arbitrarily combining any of the lower limit values and the upper limit values. For example, in one embodiment, the linear transmittance after heating is preferably 85 to 99.8%, and may be, for example, any one of 87.5 to 99.8%, 90 to 99.8%, and 94 to 99.8%. However, these ranges are only one example of the linear transmittance after heating.

The linear transmittance of light (400 to 800nm) before heating and the linear transmittance after heating can be measured by a known method using a spectrophotometer.

The heating condition of the film-like adhesive, which is 260 ℃ for 10 minutes when the linear transmittance after heating is defined, is set in consideration of the conditions in the heating step such as the reflow step.

The shear strength of the film-like adhesive of the present embodiment is not particularly limited, but is preferably 20N/2mm □ or more, and may be, for example, 50N/2mm □ or more, 60N/2mm □ or more, 70N/2mm □ or more, or 78N/2mm □ or more. When the shear strength of the film-like adhesive is not less than the lower limit, the adhesive force to the object to be attached becomes stronger.

In the present specification, the unit "N/2 mm □" has the same meaning as "N/(2 mm. times.2 mm)".

The upper limit of the shear strength of the film-like adhesive is not particularly limited.

For example, a film-like adhesive having a shear strength of 300N/2mm □ or less can be produced more easily.

The shear strength of the film-like adhesive can be appropriately adjusted within a range set by arbitrarily combining any of the lower limit values and the upper limit value described above. For example, in one embodiment, the shear strength is preferably 20-300N/2 mm □, and may be, for example, any of 50-300N/2 mm □, 60-300N/2 mm □, 70-300N/2 mm □, and 78-300N/2 mm □. However, these ranges are only one example of the shear strength.

The shear strength of the film-shaped adhesive in the present embodiment is measured by the method shown below.

(method of measuring shear Strength of film-shaped adhesive)

A test piece was prepared by using a film-like adhesive having a size of 2mm × 2mm and a thickness of 20 μm, a copper plate having a size of 30mm × 30mm and a thickness of 300 μm, and a silicon chip, and adhering the entire surface of one surface of the film-like adhesive to the surface of the silicon chip and the entire surface of the other surface to the surface of the copper plate. On at least one side surface of the test piece, the film-like adhesive is aligned with the side surface of the silicon chip.

A force was applied to the film-like adhesive and the silicon wafer at a speed of 200 μm/s in a direction parallel to the other surface of the film-like adhesive on the side surface of the test piece on which the alignment was performed under a temperature condition of 23 ℃, and the maximum value of the force applied until the film-like adhesive was broken was used as the shear strength (N/2mm □) of the film-like adhesive.

In the film-like adhesive, at least one side thereof is substantially free of aromatic compounds, and preferably both sides thereof are substantially free of aromatic compounds.

The film-like adhesive of a single layer generally shows no variation in its composition and has high uniformity of composition. Therefore, a significant difference in the type and content of the components contained in the film-like adhesive of a single layer cannot be observed on both sides of the film-like adhesive, or even if a difference is observed, the effect of the difference is negligible.

In the single-layer film-shaped adhesive, if at least one surface thereof contains substantially no aromatic compound, it is determined that the entire film-shaped adhesive and the other surface thereof also contain substantially no aromatic compound.

In the present specification, the phrase "the film-like adhesive contains substantially no aromatic compound" means that the film-like adhesive contains no aromatic compound at all, or even if the film-like adhesive contains an aromatic compound, the effect of the aromatic compound is negligible, and the film-like adhesive exhibits the same characteristics as the film-like adhesive containing no aromatic compound.

In the present embodiment, it can be confirmed that the face (i.e., the one face or both faces) of the film-like adhesive is substantially free of aromatic compounds by: when a surface to be coated with a film-like adhesive is analyzed by Fourier Transform Infrared Spectroscopy (hereinafter, abbreviated as "FT-IR" in some cases), the wave number is 3050 to 2990cm^-1There is no inflection point in the curve showing the transmittance. At a wave number of 3050-2990 cm^-1The main functional group that can be determined in the range of (a) is only an aromatic cyclic group, and if there is no inflection point in a curve showing transmittance in the wave number region, it can be determined that no aromatic cyclic group is present on the analysis target surface and no aromatic compound is contained. Here, the meaning of "no inflection point" is the same as that no peak except noise exists in the curve showing transmittance.

The film-like adhesive may be composed of one layer (single layer) or a plurality of layers of two or more layers, and when composed of a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited.

In the present specification, the phrase "a plurality of layers may be the same or different from each other" means "all the layers may be the same or all the layers may be different from each other, and only a part of the layers may be the same", and "a plurality of layers are different from each other" means "at least one of the constituent material and the thickness of each layer is different from each other".

The film-like binder preferably has a thickness of 10 to 40 μm, and may be, for example, any one of 10 to 35 μm, 10 to 30 μm and 10 to 25 μm, any one of 13 to 40 μm, 16 to 40 μm and 19 to 40 μm, or any one of 13 to 35 μm, 16 to 30 μm and 19 to 25 μm. When the thickness of the film-like adhesive is equal to or more than the lower limit, the adhesive force of the film-like adhesive to the object to be adhered is further enhanced. By setting the thickness of the film-like adhesive to the upper limit or less, the linear transmittance of the film-like adhesive to light (for example, light (400 to 800nm)) is increased regardless of heating.

The "thickness of the film-like adhesive" refers to the thickness of the entire film-like adhesive, and for example, the thickness of the film-like adhesive composed of a plurality of layers refers to the total thickness of all the layers constituting the film-like adhesive.

Preferable examples of the film-like adhesive include a film-like adhesive having a linear transmittance of light (400 to 800nm) of 90% or more before heating, a linear transmittance of light (400 to 800nm) of 85% or more after heating, and a thickness of 10 to 40 μm.

The above-mentioned properties of the film-like adhesive (the linear transmittance before heating of light (400 to 800nm), the linear transmittance after heating of light (400 to 800nm), the shear strength, and the FT-IR characteristic) can be adjusted by adjusting the kind and content of the components contained in the film-like adhesive, for example.

Among the film-shaped adhesives, preferable ones include, for example, one or more film-shaped adhesives containing one or more selected from the group consisting of an acrylic resin (a), an epoxy compound (b1), and a phosphorus antioxidant (z).

Adhesive composition

The film-shaped adhesive can be formed using an adhesive composition containing a constituent material thereof (for example, one or more selected from the group consisting of an acrylic resin (a), an epoxy compound (b1), and a phosphorus antioxidant (z)). For example, a film-like adhesive can be formed at a target site by applying an adhesive composition to a surface to be formed with the film-like adhesive and drying the adhesive composition as needed.

The content ratio of the components that do not vaporize at normal temperature in the adhesive composition is generally the same as the content ratio of the components of the film-shaped adhesive. In the present specification, "normal temperature" means a temperature at which cooling or heating is not particularly performed, that is, a normal temperature, and examples thereof include a temperature of 15 to 25 ℃.

The adhesive composition may be applied by a known method, and examples thereof include a method using various coating machines such as an air knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a curtain coater, a die coater, a knife coater, a screen coater, a meyer bar coater, and a kiss coater.

The drying conditions of the adhesive composition are not particularly limited, but when the adhesive composition contains a solvent described later, it is preferably dried by heating. The binder composition containing a solvent is preferably dried at 70 to 130 ℃ for 10 seconds to 5 minutes, for example.

The components contained in the film-like adhesive and the adhesive composition will be described in detail below.

< acrylic resin (a) >)

The acrylic resin (a) may be a component obtained by polymerizing one or more selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid esters, and derivatives thereof.

In the present specification, unless otherwise specified, "derivative" refers to a compound having a structure in which 1 or more groups of the original compound are substituted with a group (substituent) other than the group. The "group" includes not only an atomic group in which a plurality of atoms are bonded but also 1 atom.

The acrylic resin (a) is a resin component for imparting film-like adhesive agent with film-forming properties or flexibility and the like and improving adhesiveness (attachment property) to an object to be bonded such as the chip.

In the present specification, "(meth) acrylic acid" is a concept including both "acrylic acid" and "methacrylic acid". Similar terms to (meth) acrylic acid are also the same.

The acrylic resin (a) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

As the acrylic resin (a), a known acrylic polymer can be mentioned.

The weight average molecular weight (Mw) of the acrylic resin (a) is preferably 10000 to 2000000, more preferably 100000 to 1500000. When the weight average molecular weight of the acrylic resin (a) is in this range, the adhesive force between the film-shaped adhesive and the adherend can be easily adjusted to a preferable range.

On the other hand, by setting the weight average molecular weight of the acrylic resin (a) to the lower limit or more, the shape stability (stability with time during storage) of the film-like adhesive is improved. Further, by setting the weight average molecular weight of the acrylic resin (a) to be not more than the upper limit, the film-shaped pressure-sensitive adhesive can easily follow the uneven surface of the adherend, and generation of voids (void) and the like between the adherend and the film-shaped pressure-sensitive adhesive can be further suppressed.

In the present specification, unless otherwise specified, "weight average molecular weight" refers to a polystyrene equivalent value measured by a Gel Permeation Chromatography (GPC) method.

The glass transition temperature (Tg) of the acrylic resin (a) is preferably-60 to 70 ℃, more preferably-30 to 50 ℃. When the Tg of the acrylic resin (a) is not less than the lower limit, the adhesive force between the film-shaped adhesive and the adherend is suppressed, and for example, separation of the chip provided with the film-shaped adhesive from a dicing sheet described later becomes easier in picking up. When the Tg of the acrylic resin (a) is not more than the upper limit, the adhesive force between the film-like adhesive and the adherend is improved.

Examples of the (meth) acrylic ester constituting the acrylic resin (a) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, dodecyl (meth) acrylate, and the like, Alkyl (meth) acrylates having a chain structure in which the alkyl group constituting the alkyl ester is 1 to 18 carbon atoms, such as tetradecyl (meth) acrylate (myristyl (meth) acrylate), pentadecyl (meth) acrylate, hexadecyl (meth) acrylate (palmityl (meth) acrylate), heptadecyl (meth) acrylate, and octadecyl (meth) acrylate (stearyl (meth) acrylate);

cycloalkyl (meth) acrylates such as isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate;

aralkyl (meth) acrylates such as benzyl (meth) acrylate;

cycloalkenyl (meth) acrylates such as dicyclopentenyl (meth) acrylate;

cycloalkenyloxyalkyl (meth) acrylates such as dicyclopentenyloxyethyl (meth) acrylate;

(meth) acrylic acid imide;

glycidyl group-containing (meth) acrylates such as glycidyl (meth) acrylate;

hydroxyl group-containing (meth) acrylates such as hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate;

and substituted amino group-containing (meth) acrylates such as N-methylaminoethyl (meth) acrylate. Here, "substituted amino group" refers to a group having a structure in which one or two hydrogen atoms of an amino group are substituted with a group other than a hydrogen atom.

The acrylic resin (a) may be obtained by copolymerizing one or more monomers selected from (meth) acrylic acid, itaconic acid, vinyl acetate, acrylonitrile, styrene, N-methylolacrylamide, and the like, in addition to the (meth) acrylate.

The acrylic resin (a) may be composed of only one monomer, or may be composed of two or more monomers, and when the number of monomers is two or more, the combination and ratio thereof may be arbitrarily selected.

The acrylic resin (a) may have, in addition to the above-mentioned hydroxyl group, a functional group capable of bonding to other compounds, such as a vinyl group, (meth) acryloyl group, amino group, carboxyl group, isocyanate group, and the like. The functional group such as a hydroxyl group of the acrylic resin (a) may be bonded to another compound via a crosslinking agent (f) described later, or may be directly bonded to another compound without the crosslinking agent (f). The acrylic resin (a) is bonded to another compound via the functional group, and thus the reliability of a package obtained using the film-like adhesive tends to be improved.

Examples of the preferable acrylic resin of the acrylic resin (a) include acrylic resins having a functional group capable of bonding to a crosslinking agent (f) described later.

In the adhesive composition, the proportion of the content of the acrylic resin (a) to the total content of all the components except the solvent (i.e., the proportion of the content of the acrylic resin (a) in the film-shaped adhesive to the total mass of the film-shaped adhesive) is preferably 10 to 90% by mass, more preferably 15 to 70% by mass, further preferably 20 to 65% by mass, and may be, for example, any one of 30 to 55% by mass and 30 to 50% by mass. By setting the ratio to the lower limit or more, the structure of the film-like adhesive is more stable. When the ratio is not more than the upper limit, for example, the amount of the component other than the acrylic resin (a), such as the epoxy compound (b1) and the phosphorus antioxidant (z), can be easily increased, and the effect of using the component other than the acrylic resin (a) can be more easily obtained.

< epoxy Compound (b1) >)

The epoxy compound (b1) may be either a resin component or a non-resin component.

Examples of the epoxy compound (b1) include known epoxy compounds, and examples thereof include epoxy compounds having two or more functionalities such as polyfunctional epoxy resins, biphenyl compounds, bisphenol a diglycidyl ether and hydrogenated products thereof, o-cresol novolac epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, bisphenol a epoxy resins, bisphenol F epoxy resins, phenylene skeleton epoxy resins, and triazine alicyclic epoxy compounds.

As the epoxy compound (b1), an epoxy compound having an unsaturated hydrocarbon group can be used. The compatibility of the epoxy compound having an unsaturated hydrocarbon group with the acrylic resin (a) is higher than the compatibility of the epoxy compound having no unsaturated hydrocarbon group with the acrylic resin (a). Therefore, by using the epoxy compound (b1) having an unsaturated hydrocarbon group, the reliability of the package obtained by using the film-like adhesive is improved.

Examples of the epoxy compound (b1) having an unsaturated hydrocarbon group include compounds having a structure in which a part of epoxy groups of a polyfunctional epoxy compound is converted into a group having an unsaturated hydrocarbon group. Such a compound can be obtained, for example, by addition reaction of (meth) acrylic acid or a derivative thereof with an epoxy group.

Examples of the unsaturated hydrocarbon group-containing epoxy compound (b1) include compounds in which an unsaturated hydrocarbon group-containing group is directly bonded to an aromatic ring or the like constituting the epoxy compound.

The unsaturated hydrocarbon group is a polymerizable unsaturated group, and specific examples thereof include an ethylene group (vinyl group), a 2-propenyl group (allyl group), (meth) acryloyl group, and (meth) acrylamido group, with acryloyl group being preferred.

The number average molecular weight of the epoxy compound (b1) (in other words, the epoxy resin (b1)) as the resin component is not particularly limited, but is preferably 300 to 30000, more preferably 400 to 10000, and particularly preferably 500 to 3000, in view of curability of the film-shaped adhesive and strength and heat resistance of a cured product of the film-shaped adhesive.

The epoxy equivalent of the epoxy compound (b1) is preferably 100 to 1000g/eq, more preferably 120 to 600 g/eq.

The epoxy compound (b1) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

The epoxy compound (b1) is preferably an aliphatic compound. That is, the film-shaped adhesive preferably contains an aliphatic epoxy compound.

In the present specification, the term "aliphatic compound" refers to a compound having an aliphatic group and no aromatic group. The "aliphatic group" includes a chain aliphatic group and an alicyclic group (also called an alicyclic group). The "aromatic group" includes an aromatic hydrocarbon group and an aromatic heterocyclic group.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as the epoxy compound (b1), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the film-like adhesive contains only an aliphatic compound (in other words, does not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

The epoxy compound (b1) preferably does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the adhesive composition and the film-like adhesive contain a compound having no bond or group as the epoxy compound (b1), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

Preferably, the epoxy compound (b1) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N). That is, the film-shaped adhesive preferably contains an aliphatic epoxy compound, and the aliphatic epoxy compound does not have one or more selected from the group consisting of a triple bond between carbon atoms, a double bond between carbon atoms, and a cyano group.

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as the epoxy compound (b1), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when only the aliphatic compound having no bond or group is contained (in other words, the aliphatic compound having a bond or group is not contained), the effect of suppressing coloration is significantly increased.

In the adhesive composition and the film-like adhesive, the content of the epoxy compound (b1) is preferably 5 to 500 parts by mass, for example, may be in any range of 5 to 200 parts by mass, 5 to 150 parts by mass, 5 to 110 parts by mass, and 5 to 100 parts by mass, or may be in any range of 10 to 110 parts by mass, 25 to 110 parts by mass, and 40 to 110 parts by mass, based on 100 parts by mass of the content of the acrylic resin (a). By making the content of the epoxy compound (b1) in the above range, the adhesive force between the film-like adhesive and a resin film or a dicing sheet described later can be adjusted more easily.

< phosphorus antioxidant (z) >

Since the film-shaped adhesive contains the phosphorus-based antioxidant (z), the coloring before and after heating is further suppressed.

The phosphorus-based antioxidant (z) is not particularly limited as long as it has a phosphorus atom as its constituent atom and has an antioxidant effect.

Examples of the phosphorus-based antioxidant (z) include compounds having an oxidation number of phosphorus of 3.

The phosphorus-based antioxidant (z) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

The phosphorus-based antioxidant (z) is preferably an aliphatic compound.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as the phosphorus antioxidant (z), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the film-like adhesive contains only an aliphatic compound (in other words, does not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

The phosphorus-based antioxidant (z) preferably does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the pressure-sensitive adhesive composition and the film-like pressure-sensitive adhesive contain a compound having no bond or group as the phosphorus-based antioxidant (z), the effect of suppressing coloration of the film-like pressure-sensitive adhesive after heating (for example, heating at 260 ℃) is further increased, and when the pressure-sensitive adhesive composition and the film-like pressure-sensitive adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

The phosphorus-based antioxidant (z) is preferably an aliphatic compound, and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N).

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as the phosphorus antioxidant (z), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when only an aliphatic compound having no bond or group is contained (in other words, an aliphatic compound having a bond or group is not contained), the effect of suppressing coloration is significantly increased.

The phosphorus-based antioxidant (z) is preferably a phosphite in terms of stably exhibiting an antioxidant effect.

Among these, the phosphorus-based antioxidant (z) is more preferably an aliphatic phosphite ester, and still more preferably an aliphatic trialkyl phosphite ester.

That is, the film-like adhesive preferably contains a phosphite ester as an antioxidant, more preferably contains an aliphatic phosphite ester as an antioxidant, and still more preferably contains an aliphatic trialkyl phosphite as an antioxidant.

Examples of the aliphatic trialkyl phosphite include phosphorous acidTriethyl ester ((C)₂H₅O)₃P), tris (2-ethylhexyl) phosphite ((CH)₃CH₂CH₂CH₂CH(CH₂CH₃)CH₂O)₃P), tridecyl phosphite ((C)₁₀H₂₁O)₃P), tridodecyl phosphite ((C)₁₂H₂₅O)₃P), tridecyl tris (phosphate ((C)₁₃H₂₇O)₃P), trioctadecyl phosphite ((C)₁₈H₃₇O)₃P), bis (decyl) pentaerythritol diphosphite (C)₁₀H₂₁OP(OCH₂)₂C(CH₂O)₂POC₁₀H₂₁) Bis (tridecyl) pentaerythritol diphosphite (C)₁₃H₂₇OP(OCH₂)₂C(CH₂O)₂POC₁₃H₂₇) Distearyl pentaerythritol diphosphite (C)₁₈H₃₇OP(OCH₂)₂C(CH₂O)₂POC₁₈H₃₇) Hydrogenated bisphenol A-pentaerythritol phosphite polymer (having the formula "- (OC)₆H₁₂C(CH₃)₂C₆H₁₂OP(OCH₂)₂C(CH₂O)₂A polymer of a repeating unit represented by P) - "), and the like.

In the adhesive composition, the content of the phosphorus-based antioxidant (z) is preferably 0.1 to 5% by mass, more preferably 0.2 to 3% by mass, even more preferably 0.3 to 1.5% by mass, and for example, may be 0.3 to 1% by mass, based on the total content of all components except the solvent (i.e., the content of the phosphorus-based antioxidant (z) in the film-shaped adhesive based on the total mass of the film-shaped adhesive). When the ratio is not less than the lower limit, the effect of using the phosphorus-based antioxidant (z) can be more remarkably obtained. When the ratio is not more than the upper limit, the excessive use of the phosphorus-based antioxidant (z) can be suppressed.

In order to improve various physical properties of the film-shaped adhesive, other components not belonging to any of the acrylic resin (a), the epoxy compound (b1) and the phosphorus antioxidant (z) may be further contained as necessary in addition to the acrylic resin (a), the epoxy compound (b1) and the phosphorus antioxidant (z).

Examples of the other components contained in the film-like binder include a phenol resin (b2), a curing accelerator (c), a filler (d), a coupling agent (e), a crosslinking agent (f), an energy ray-curable resin (g), a photopolymerization initiator (h), an antioxidant (y) other than a phosphorus-removing antioxidant (z) (in the present specification, this antioxidant may be abbreviated as "other antioxidant (y)"), a thermoplastic resin (x) other than the acrylic resin (a) (in the present specification, this antioxidant may be abbreviated as "thermoplastic resin (x)"), and a general-purpose additive (i).

< phenolic resin (b2) >)

The phenol resin (b2) functions as a heat curing agent for the epoxy compound (b 1).

In the present embodiment, when the epoxy compound (b1) and the phenol resin (b2) are used together, the combination of these functions as an epoxy thermosetting resin. In the present embodiment, the epoxy thermosetting resin may be referred to as "epoxy thermosetting resin (b)".

The phenolic resin (b2) may have 2 or more phenolic hydroxyl groups in one molecule as functional groups reactive with epoxy groups.

Examples of the phenol resin (b2) include a polyfunctional phenol resin, a novolak phenol resin, a dicyclopentadiene phenol resin, and an aralkyl phenol resin.

The phenol resin (b2) may have an unsaturated hydrocarbon group.

Examples of the other phenol resin (b2) having an unsaturated hydrocarbon group include a compound having a structure in which a part of the hydroxyl groups of the phenol resin is substituted with a group having an unsaturated hydrocarbon group, a compound having a structure in which a group having an unsaturated hydrocarbon group is directly bonded to an aromatic ring of the phenol resin, and the like.

The unsaturated hydrocarbon group in the phenolic resin (b2) is the same as the unsaturated hydrocarbon group in the above-mentioned epoxy compound having an unsaturated hydrocarbon group.

The softening point or glass transition temperature of the phenolic resin (b2) is preferably high from the point where the adhesive force of the film-like adhesive can be easily adjusted.

The number average molecular weight of the phenolic resin (b2) is preferably 300 to 30000, more preferably 400 to 10000, and particularly preferably 500 to 3000.

The phenolic resin (b2) contained in the adhesive composition and the film-like adhesive may be one type or two or more types, and when two or more types are used, the combination and ratio thereof may be arbitrarily selected.

When the phenolic resin (b2) is used, the proportion of the content of the phenolic resin (b2) to the total content of all the components except the solvent in the adhesive composition (that is, the proportion of the content of the phenolic resin (b2) in the film-shaped adhesive to the total mass of the film-shaped adhesive) is not particularly limited, but is preferably 10 mass% or less, more preferably 7.5 mass% or less, and still more preferably 5 mass% or less. When the ratio is not more than the upper limit, the effect of suppressing coloring after heating (for example, heating at 260 ℃) of the film-like adhesive is further increased.

That is, as an example of a preferable film-shaped adhesive among the film-shaped adhesives containing the phenolic resin (b2), a film-shaped adhesive in which the content of the phenolic resin (b2) in the film-shaped adhesive is 10 mass% or less with respect to the total mass of the film-shaped adhesive can be cited.

When the phenolic resin (b2) is used, the lower limit of the proportion of the content of the phenolic resin (b2) to the total content of all the components except the solvent in the adhesive composition (that is, the proportion of the content of the phenolic resin (b2) in the film-like adhesive to the total mass of the film-like adhesive) is not particularly limited.

For example, the ratio is preferably 0.5 mass% or more in terms of more remarkably obtaining the effect of using the phenol resin (b 2).

When the phenol resin (b2) is used, the ratio can be appropriately adjusted within a range set by arbitrarily combining the lower limit value with any upper limit value. For example, in one embodiment, the ratio is preferably 0.5 to 10% by mass, more preferably 0.5 to 7.5% by mass, and still more preferably 0.5 to 5% by mass.

When the phenol resin (b2) is used, the content of the phenol resin (b2) may be, for example, any one of 3 to 30 parts by mass, 3 to 25 parts by mass and 3 to 20 parts by mass, 5 to 30 parts by mass, 10 to 30 parts by mass and 15 to 30 parts by mass, or 5 to 25 parts by mass and 10 to 20 parts by mass, based on 100 parts by mass of the epoxy compound (b1) in the adhesive composition and the film-like adhesive.

< curing Accelerator (c) >)

The curing accelerator (c) is a component for adjusting the curing speed of the adhesive composition and the film-like adhesive.

Examples of the preferable curing accelerator (c) include tertiary amines such as triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris (dimethylaminomethyl) phenol; imidazoles (imidazole in which one or more hydrogen atoms are replaced with a group other than a hydrogen atom) such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4, 5-dihydroxymethylimidazole, and 2-phenyl-4-methyl-5-hydroxymethylimidazole; organic phosphines such as tributylphosphine, diphenylphosphine, and triphenylphosphine (phosphines in which one or more hydrogen atoms are substituted with an organic group); tetraphenylboron salts such as tetraphenylphosphonium tetraphenylphosphonate, triphenylphosphine tetraphenylboronate and the like; and an inclusion compound using the imidazole as a guest compound.

The curing accelerator (c) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the curing accelerator (c) is used, the content of the curing accelerator (c) is preferably 0.01 to 7 parts by mass, more preferably 0.1 to 4 parts by mass, based on 100 parts by mass of the total content of the epoxy compound (b1) and the phenolic resin (b2) in the adhesive composition and the film-like adhesive. By setting the content of the curing accelerator (c) to the lower limit or more, the effect of using the curing accelerator (c) can be more remarkably obtained. When the content of the curing accelerator (c) is not more than the above upper limit, for example, the effect of suppressing the migration of the highly polar curing accelerator (c) to the side of the adhesive interface with the adherend in the film-like adhesive under high temperature and high humidity conditions and the occurrence of segregation increases, and the reliability of the package obtained using the film-like adhesive is further improved. When the phenol resin (b2) is not used, the total content of the epoxy compound (b1) and the phenol resin (b2) is the content of the epoxy compound (b 1).

< filling Material (d) >)

By containing the filler (d) in the film-like adhesive, the thermal expansion coefficient of the film-like adhesive can be easily adjusted, and by optimizing the thermal expansion coefficient with respect to the object to which the film-like adhesive is attached, the reliability of the package obtained by using the film-like adhesive can be further improved. Further, by containing the filler (d) in the film-shaped adhesive, the moisture absorption rate of the cured product of the film-shaped adhesive can be reduced or the heat dissipation property can be improved.

The filler (d) may be any of an organic filler and an inorganic filler, and is preferably an inorganic filler.

Examples of preferable inorganic fillers include powders of silica, alumina, talc, calcium carbonate, titanium white, red iron oxide, silicon carbide, boron nitride, and the like; beads (beads) obtained by spheroidizing these inorganic fillers; surface modifications of these inorganic filler materials; single crystal fibers of these inorganic filler materials; glass fibers, and the like.

Among them, the inorganic filler is preferably silica or a surface-modified product thereof.

The average particle diameter of the filler (d) is not particularly limited, but is preferably 10 to 100nm, more preferably 10 to 80nm, and still more preferably 10 to 60 nm. When the average particle diameter of the filler (d) is not more than the upper limit, the film-shaped adhesive is highly inhibited from clouding, and the film-shaped adhesive is improved in the linear transmittance before heating and the linear transmittance after heating to light (400 to 800nm), and as a result, the image visibility of the film-shaped adhesive before heating and after heating is further improved. By setting the average particle diameter of the filler (d) to the lower limit or more, the effect of using the filler (d) can be more remarkably obtained.

In addition, unless otherwise specified, "average particle diameter" in the present specification means a particle diameter (D) at a cumulative value of 50% in a particle size distribution curve obtained by a laser diffraction scattering method₅₀) The value of (c).

The filler (d) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the filler (d) is used, the ratio of the content of the filler (d) to the total content of all the components except the solvent in the adhesive composition (i.e., the ratio of the content of the filler (d) in the film-shaped adhesive to the total mass of the film-shaped adhesive) is preferably 7.5 to 50% by mass, and may be, for example, any one of 10 to 45% by mass and 10 to 40% by mass. By setting the content of the filler (d) to the above range, the adjustment of the thermal expansion coefficient becomes easier.

< coupling agent (e) >)

When the film-shaped pressure-sensitive adhesive contains the coupling agent (e), the adhesiveness to an adherend and the adhesion are improved. Further, by incorporating the coupling agent (e) into the film-like adhesive, the water resistance of the cured product is improved without impairing the heat resistance. The coupling agent (e) has a functional group reactive with an inorganic compound or an organic compound.

The coupling agent (e) is preferably a compound having a functional group capable of reacting with a functional group of the acrylic resin (a), the epoxy thermosetting resin (b), or the like, and more preferably a silane coupling agent.

Examples of the preferable silane coupling agent include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propylmethyldiethoxysilane, 3- (phenylamino) propyltrimethoxysilane, 3-anilinopropyltrimethoxysilane, 3-ureopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, and the like, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, imidazolesilane, oligomeric or polymeric organosiloxanes, and the like.

The coupling agent (e) is preferably an aliphatic compound.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as the coupling agent (e), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only an aliphatic compound (in other words, do not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

Preferably, the coupling agent (e) does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the adhesive composition and the film-like adhesive contain a compound having no bond or group as the coupling agent (e), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

Preferably, the coupling agent (e) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N).

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as the coupling agent (e), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when only the aliphatic compound having no bond or group is contained (in other words, the aliphatic compound having a bond or group is not contained), the effect of suppressing coloration is significantly increased.

More specific examples of the aliphatic compound (aliphatic coupling agent) in the coupling agent (e) include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxymethyldiethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethylamino) propyltrimethoxysilane, 3- (2-aminoethylamino) propylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and mixtures thereof, 3-mercaptopropylmethyldimethoxysilane, bis (3-triethoxysilylpropyl) tetrasulfide, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriacetoxysilane, oligomeric or polymeric organosiloxanes, and the like.

The coupling agent (e) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the coupling agent (e) is used, the content of the coupling agent (e) is preferably 0.03 to 20 parts by mass, more preferably 0.05 to 10 parts by mass, and particularly preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the total content of the acrylic resin (a) and the epoxy thermosetting resin (b) in the adhesive composition and the film-like adhesive. When the content of the coupling agent (e) is not less than the lower limit, the effects of using the coupling agent (e), that is, the improvement of the dispersibility of the filler (d) in the resin, the improvement of the adhesiveness between the film-shaped adhesive and the adherend, and the like can be more remarkably obtained. By setting the content of the coupling agent (e) to the upper limit value or less, the occurrence of degassing can be further suppressed.

< crosslinking agent (f) >)

When a component having a functional group such as a vinyl group, (meth) acryloyl group, amino group, hydroxyl group, carboxyl group, or isocyanate group, which is capable of bonding to the other compounds, is used as the acrylic resin (a), the adhesive composition and the film-shaped adhesive may contain a crosslinking agent (f) for bonding and crosslinking the functional group to the other compounds. The crosslinking with the crosslinking agent (f) can adjust the initial adhesive force and cohesive force of the film-like adhesive.

Examples of the crosslinking agent (f) include an organic polyisocyanate compound, an organic polyimine compound, a metal chelate crosslinking agent (a crosslinking agent having a metal chelate structure), an aziridine crosslinking agent (a crosslinking agent having an aziridine group), and the like.

Examples of the organic polyisocyanate compound include an aromatic polyisocyanate compound, an aliphatic polyisocyanate compound, and an alicyclic polyisocyanate compound (hereinafter, these compounds may be collectively abbreviated as "aromatic polyisocyanate compound, etc.); trimers, isocyanurate bodies and adducts of the aromatic polyisocyanate compounds and the like; and isocyanate-terminated urethane prepolymers obtained by reacting the aromatic polyisocyanate compound and the like with a polyol compound. The "adduct" refers to a reactant of the aromatic polyisocyanate compound, aliphatic polyisocyanate compound or alicyclic polyisocyanate compound with a low-molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane or castor oil. Examples of the adduct include a xylylene diisocyanate adduct of trimethylolpropane, an isophorone diisocyanate adduct of trimethylolpropane, a tolylene diisocyanate adduct of trimethylolpropane, and a hexamethylene diisocyanate adduct of trimethylolpropane, which are described below. The "isocyanate-terminated urethane prepolymer" refers to a prepolymer having a urethane bond and an isocyanate group at the terminal of the molecule.

More specifically, the organic polyisocyanate compound includes, for example, 2,4-

Toluene diisocyanate; 2, 6-toluene diisocyanate; 1, 3-xylylene diisocyanate; 1, 4-xylylene diisocyanate; diphenylmethane-4, 4' -diisocyanate; diphenylmethane-2, 4' -diisocyanate; 3-methyl diphenylmethane diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4, 4' -diisocyanate; dicyclohexylmethane-2, 4' -diisocyanate; a compound obtained by adding one or more of toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate to all or part of the hydroxyl groups of a polyhydric alcohol such as trimethylolpropane; lysine diisocyanate, and the like.

Examples of the organic polyimine compound include N, N ' -diphenylmethane-4, 4 ' -bis (1-aziridinecarboxamide), trimethylolpropane-tri- β -aziridinylpropionate, tetramethylolmethane-tri- β -aziridinylpropionate, and N, N ' -toluene-2, 4-bis (1-aziridinecarboxamide) triethylenemelamine.

When an organic polyisocyanate compound is used as the crosslinking agent (f), a hydroxyl group-containing polymer is preferably used as the acrylic resin (a). When the crosslinking agent (f) has an isocyanate group and the acrylic resin (a) has a hydroxyl group, the crosslinked structure can be easily introduced into the film-like adhesive by the reaction of the crosslinking agent (f) with the acrylic resin (a).

The crosslinking agent (f) is preferably an aliphatic compound.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as the crosslinking agent (f), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only an aliphatic compound (in other words, do not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

The crosslinking agent (f) preferably does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the adhesive composition and the film-like adhesive contain a compound having no bond or group as the crosslinking agent (f), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

Preferably, the crosslinking agent (f) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N).

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as the crosslinking agent (f), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when only the aliphatic compound having no bond or group is contained (in other words, the aliphatic compound having a bond or group is not contained), the effect of suppressing coloration is significantly increased.

The crosslinking agent (f) is preferably an aliphatic organic polyisocyanate compound (aliphatic polyisocyanate crosslinking agent) in view of the fact that the effect of suppressing the coloring is particularly high and the crosslinking agent has excellent properties as a crosslinking agent.

More specifically, the aliphatic polyisocyanate crosslinking agent includes, for example, 2, 4-tolylene diisocyanate; 2, 6-toluene diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate; dicyclohexylmethane-4, 4' -diisocyanate; dicyclohexylmethane-2, 4' -diisocyanate; a compound obtained by adding one or more of toluene diisocyanate, isophorone diisocyanate and hexamethylene diisocyanate to all or a part of the hydroxyl groups of a polyol such as trimethylolpropane; lysine diisocyanate, and the like.

In the case of the acrylic resin (a) and the crosslinking agent (f), it is preferable that the film-like adhesive contains the aliphatic polyisocyanate crosslinking agent as the crosslinking agent (f) and contains a component having a functional group capable of bonding to the aliphatic polyisocyanate crosslinking agent as the acrylic resin (a) in view of the fact that the effect of suppressing the coloring is particularly high and the film-like adhesive has excellent properties.

The crosslinking agent (f) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the crosslinking agent (f) is used, the content of the crosslinking agent (f) is preferably 0.3 to 12 parts by mass, more preferably 0.3 to 3.5 parts by mass, and still more preferably 0.3 to 2 parts by mass, based on 100 parts by mass of the acrylic resin (a) in the adhesive composition and the film-like adhesive. By setting the content of the crosslinking agent (f) to the lower limit or more, the effect of using the crosslinking agent (f) can be more remarkably obtained. Further, by making the content of the crosslinking agent (f) the upper limit value or less, the excessive use of the crosslinking agent (f) can be suppressed.

< energy ray-curable resin (g) >)

The adhesive composition and the film-like adhesive may contain an energy ray-curable resin (g). By containing the energy ray-curable resin (g) in the film-like adhesive, the properties can be changed by irradiation with an energy ray.

In the present specification, the "energy ray" refers to a ray having an energy quantum in an electromagnetic wave or a charged particle beam, and examples thereof include ultraviolet rays, radiation, an electron beam, and the like.

For example, the ultraviolet rays can be irradiated by using a high-pressure mercury lamp, a fusion lamp (fusion lamp), a xenon lamp, a black light lamp, an LED lamp, or the like as an ultraviolet ray source. The electron beam can be irradiated with an electron beam generated by an electron beam accelerator or the like.

In the present specification, "energy ray-curable property" refers to a property of curing by irradiation with an energy ray, and "non-energy ray-curable property" refers to a property of not curing even by irradiation with an energy ray.

The energy ray-curable resin (g) is obtained by polymerizing (curing) an energy ray-curable compound.

Examples of the energy ray-curable compound include compounds having at least one polymerizable double bond in the molecule, and acrylate compounds having a (meth) acryloyl group are preferable.

Examples of the acrylic ester-based compound include (meth) acrylates having a chain-like aliphatic skeleton such as trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol monohydroxypenta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1, 4-butanediol di (meth) acrylate, and 1, 6-hexanediol di (meth) acrylate; a (meth) acrylate having a cyclic aliphatic skeleton such as dicyclopentanyl di (meth) acrylate; polyalkylene glycol (meth) acrylates such as polyethylene glycol di (meth) acrylate; an oligoester (meth) acrylate; a urethane (meth) acrylate oligomer; epoxy-modified (meth) acrylates; a polyether (meth) acrylate other than the polyalkylene glycol (meth) acrylate; itaconic acid oligomers, and the like.

The weight average molecular weight of the energy ray curable resin (g) is preferably 100 to 30000, more preferably 300 to 10000.

The energy ray-curable resin (g) contained in the adhesive composition may be one kind only, or two or more kinds, and in the case of two or more kinds, the combination and ratio thereof may be arbitrarily selected.

When the energy ray-curable resin (g) is used, the content of the energy ray-curable resin (g) in the adhesive composition is preferably 1 to 95% by mass, more preferably 5 to 90% by mass, and particularly preferably 10 to 85% by mass, based on the total mass of the adhesive composition.

< photopolymerization initiator (h) >

When the adhesive composition and the film-like adhesive contain the energy ray-curable resin (g), the photopolymerization initiator (h) may be contained in order to efficiently perform the polymerization reaction of the energy ray-curable resin (g).

Examples of the photopolymerization initiator (h) include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin benzoic acid, benzoin methyl benzoate, and benzoin dimethyl ketal; acetophenone compounds such as acetophenone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and 2, 2-dimethoxy-1, 2-diphenylethan-1-one; acylphosphine oxide compounds such as phenylbis (2,4, 6-trimethylbenzoyl) phosphine oxide and 2,4, 6-trimethylbenzoyl diphenylphosphine oxide; sulfides such as benzyl phenyl sulfide and tetramethylthiuram monosulfide; α -ketol compounds such as 1-hydroxycyclohexyl phenyl ketone; azo compounds such as azobisisobutyronitrile; titanocene compounds such as titanocene; thioxanthone compounds such as thioxanthone; a peroxide compound; diketone compounds such as diacetyl; benzil; dibenzoyl; benzophenone; 2, 4-diethylthioxanthone; 1, 2-diphenylmethane; 2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl ] propanone; quinone compounds such as 1-chloroanthraquinone and 2-chloroanthraquinone.

Examples of the photopolymerization initiator (h) include photosensitizers such as amines.

The photopolymerization initiator (h) is preferably an aliphatic compound.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as the photopolymerization initiator (h), the effect of suppressing coloration after heating (for example, heating at 260 ℃) of the film-like adhesive is further increased, and when the adhesive composition and the film-like adhesive contain only an aliphatic compound (in other words, do not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

The photopolymerization initiator (h) preferably does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the adhesive composition and the film-like adhesive contain a compound having no bond or group as the photopolymerization initiator (h), the effect of suppressing coloration after heating (for example, heating at 260 ℃) of the film-like adhesive is further increased, and when the adhesive composition and the film-like adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

The photopolymerization initiator (h) is preferably an aliphatic compound, and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N).

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as the photopolymerization initiator (h), the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when only the aliphatic compound having no bond or group is contained (in other words, the aliphatic compound having a bond or group is not contained), the effect of suppressing coloration is significantly increased.

As the aliphatic compound (aliphatic photopolymerization initiator) in the photopolymerization initiator (h), more specifically, for example, acylphosphine oxide compounds; sulfides such as tetramethylthiuram monosulfide; azo compounds such as azobisisobutyronitrile; a peroxide compound; diketone compounds such as diacetyl; photosensitizers such as amines, and the like.

Among the compounds exemplified herein, examples of the photopolymerization initiator (h) which is an aliphatic compound and does not have one or more kinds selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N) include compounds other than azobisisobutyronitrile.

The photopolymerization initiator (h) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the photopolymerization initiator (h) is used, the content of the photopolymerization initiator (h) in the adhesive composition is preferably 0.1 to 20 parts by mass, more preferably 1 to 10 parts by mass, and particularly preferably 2 to 5 parts by mass, relative to 100 parts by mass of the energy ray-curable resin (g).

< other antioxidant (y) >)

The adhesive composition and the film-like adhesive may contain the other antioxidant (y) within a range not to impair the effects of the present invention.

The other antioxidant (y) is not particularly limited as long as it is an antioxidant other than the phosphorus antioxidant (z), and may be any of an organic compound and an inorganic compound.

The other antioxidant (y) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the other antioxidant (y) is used, the content of the other antioxidant (y) in the adhesive composition and the film-like adhesive is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 1 part by mass or less, based on 100 parts by mass of the phosphorus-based antioxidant (z). When the content of the other antioxidant (y) is not more than the upper limit, the film-shaped adhesive is further inhibited from being colored before and after heating.

The adhesive composition and the film-like adhesive preferably do not contain other antioxidant (y).

< thermoplastic resin (x) >

The adhesive composition and the film-like adhesive may contain the thermoplastic resin (x) within a range not to impair the effects of the present invention.

By using the thermoplastic resin (x), for example, at the time of picking up, separation of the chip provided with the film-like adhesive from a dicing sheet described later becomes easier, the film-like adhesive easily follows the uneven surface of the adherend, and generation of voids and the like between the adherend and the film-like adhesive can be further suppressed.

The thermoplastic resin (x) is not particularly limited as long as it is a thermoplastic resin other than the acrylic resin (a).

Examples of the thermoplastic resin include polyester, polyurethane, phenoxy resin, polybutylene, polybutadiene, and polystyrene.

The weight average molecular weight of the thermoplastic resin (x) is preferably 1000 to 100000, more preferably 3000 to 80000.

The glass transition temperature (Tg) of the thermoplastic resin (x) is preferably-30 to 150 ℃, more preferably-20 to 120 ℃.

The thermoplastic resin (x) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

When the thermoplastic resin (x) is used, the content of the thermoplastic resin (x) in the adhesive composition and the film-like adhesive is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 1 part by mass or less, based on 100 parts by mass of the content of the acrylic resin (a). By setting the content of the thermoplastic resin (x) to the upper limit or less, the effect of using the acrylic resin (a) can be more remarkably obtained.

The adhesive composition and the film-like adhesive preferably do not contain the thermoplastic resin (x).

< general additive (i) >

The general-purpose additive (i) may be any known additive, and may be arbitrarily selected depending on the purpose, and is not particularly limited. Preferred examples of the general-purpose additive (I) include plasticizers, antistatic agents, colorants (dyes and pigments), and gettering agents.

When the general-purpose additive (i) is an organic compound, the above-mentioned general-purpose additive (i) (in the present specification, abbreviated as "organic general-purpose additive") is preferably an aliphatic compound.

When the adhesive composition and the film-like adhesive contain an aliphatic compound as an organic general-purpose additive, the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only an aliphatic compound (in other words, do not contain an aromatic compound), the effect of suppressing coloration is significantly increased.

It is preferable that the organic general additive does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), a cyano group (-C ≡ N), and an aromatic group.

When the adhesive composition and the film-like adhesive contain a compound having no bond or group as an organic general-purpose additive, the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only a compound having no bond or group (in other words, a compound having no bond or group), the effect of suppressing coloration is significantly increased.

Preferably, the organic general-purpose additive is an aliphatic compound, and does not have one or more selected from the group consisting of a triple bond between carbon atoms (C ≡ C), a double bond between carbon atoms (C ≡ C), and a cyano group (-C ≡ N).

When the adhesive composition and the film-like adhesive contain an aliphatic compound having no bond or group as an organic general-purpose additive, the effect of suppressing coloration of the film-like adhesive after heating (for example, heating at 260 ℃) is further increased, and when the adhesive composition and the film-like adhesive contain only an aliphatic compound having no bond or group (in other words, the adhesive composition and the film-like adhesive do not contain an aliphatic compound having a bond or group), the effect of suppressing coloration is significantly increased.

The general-purpose additive (i) contained in the adhesive composition and the film-like adhesive may be one kind or two or more kinds, and when two or more kinds are contained, the combination and ratio thereof may be arbitrarily selected.

The content of the general-purpose additive (i) in the adhesive composition and the film-like adhesive is not particularly limited, and may be appropriately selected according to the purpose.

< solvent >

The adhesive composition preferably further contains a solvent. The adhesive composition containing a solvent is excellent in workability.

The solvent is not particularly limited, but preferable examples thereof include hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 2-propanol, isobutanol (2-methylpropane-1-ol), and 1-butanol; esters such as ethyl acetate; ketones such as acetone and methyl ethyl ketone; ethers such as tetrahydrofuran; amides (compounds having an amide bond) such as dimethylformamide and N-methylpyrrolidone.

The binder composition may contain only one kind of solvent, or two or more kinds of solvents, and when two or more kinds of solvents are contained, the combination and ratio thereof may be arbitrarily selected.

The solvent contained in the pressure-sensitive adhesive composition is preferably methyl ethyl ketone or the like, from the point that the components contained in the pressure-sensitive adhesive composition can be more uniformly mixed.

Preparation method of adhesive composition

The binder composition can be obtained by blending the components for constituting the composition.

The order of addition of the components in blending is not particularly limited, and two or more components may be added simultaneously.

When the solvent is used, the solvent may be mixed with any of the components other than the solvent to dilute the components in advance, or the solvent may be mixed with the components without diluting any of the components other than the solvent to use.

When blending, the method for mixing the components is not particularly limited, and may be appropriately selected from the following known methods: a method of mixing by rotating a stirrer, a stirring blade, or the like; a method of mixing using a mixer; a method of mixing by applying ultrasonic waves, and the like.

The temperature and time for adding and mixing the components are not particularly limited and may be appropriately adjusted as long as the components are not deteriorated, but the temperature is preferably 15 to 30 ℃.

Fig. 1 is a sectional view schematically showing a film-like adhesive according to an embodiment of the present invention. For convenience, important parts of the drawings used in the following description are enlarged and shown in order to make the features of the present invention easier to understand, and the dimensional ratios of the respective components are not necessarily the same as those in reality.

The film-like adhesive 13 shown here includes a first release film 151 on one surface (in this specification, sometimes referred to as a "first surface") 13a thereof, and a second release film 152 on the other surface (in this specification, sometimes referred to as a "second surface") 13b opposite to the first surface 13 a. Here, the first release film 151, the film-like adhesive 13, and the second release film 152 are sequentially laminated in the thickness direction, and the laminate sheet is denoted by reference numeral 109.

Such a film-like adhesive 13 (laminated sheet 109) is suitably stored in a roll form, for example.

The film-like adhesive 13 has the above-described light transmittance. For example, at least one of the first surface 13a and the second surface 13b of the film-like adhesive 13 does not contain an aromatic compound.

The film-like adhesive 13 preferably has a thickness of 10 to 40 μm.

The film-shaped adhesive 13 may be formed using the adhesive composition described above.

Both the first release film 151 and the second release film 152 may be known release films.

The first release film 151 and the second release film 152 may be the same release film, or may be different release films having different release forces required for peeling from the film-like pressure-sensitive adhesive 13.

The exposed surface of the film-like adhesive 13 shown in fig. 1, which is formed by removing either the first release film 151 or the second release film 152, is a surface to be attached to an object to be attached. Here, examples of the object to be attached include the chip described above. When the object to be attached is the chip, the attachment surface of the film-like adhesive 13 is the circuit formation surface of the chip.

One preferable embodiment of the film-like adhesive includes, for example, a film-like adhesive for bonding a circuit-forming surface of a chip and a light-transmitting cover,

at least one side of the film-like adhesive is substantially free of aromatic compounds,

using the film-like adhesive having a size of 2mm × 2mm and a thickness of 20 μm, a copper plate having a size of 30mm × 30mm and a thickness of 300 μm, and a silicon chip, a test piece was prepared, the test piece being configured by attaching the entire surface of one surface of the film-like adhesive to the surface of the silicon chip and the entire surface of the other surface to the surface of the copper plate, and the positions of the film-like adhesive and the side surface of the silicon chip were aligned, and a force was applied to the film-like adhesive and the silicon chip at a speed of 200 μm/s in a direction parallel to the other surface of the film-like adhesive on the side surface of the test piece on which the position alignment was performed under a temperature condition of 23 ℃, and the maximum value of the force applied until the film-like adhesive was broken was taken as the shear strength (N/2mm □) of the film-like adhesive, the shear strength is 20N/2mm □ or more.

the film-shaped adhesive contains a phosphorus-based antioxidant (z),

the phosphorus antioxidant (z) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms, a double bond between carbon atoms, and a cyano group.

the film-like adhesive contains an epoxy compound (b1),

the epoxy compound (b1) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms, a double bond between carbon atoms, and a cyano group.

the film-like adhesive contains an acrylic resin (a) and a crosslinking agent (f),

the acrylic resin (a) has a functional group which can bond to the crosslinking agent (f),

the crosslinking agent (f) is an aliphatic compound and does not have one or more selected from the group consisting of a triple bond between carbon atoms, a double bond between carbon atoms, and a cyano group.

the film-like adhesive contains a filler (d),

the average particle diameter of the filler (d) is 10 to 100 nm.

O laminated sheet and composite sheet

The laminate sheet according to one embodiment of the present invention is configured by including the film-like adhesive and a resin film provided on one surface of the film-like adhesive.

In addition, the composite sheet according to one embodiment of the present invention includes the film-shaped adhesive and a dicing sheet provided on one surface of the film-shaped adhesive, the dicing sheet includes a substrate and an adhesive layer provided on one surface of the substrate, and the adhesive layer is disposed between the substrate and the film-shaped adhesive.

The laminate sheet may have a resin film provided on at least one surface of the film-like adhesive, and may have a resin film provided on only one surface or may have a resin film provided on both surfaces (i.e., the one surface and the other surface opposite thereto).

In the laminate sheet, when the resin films are provided on both sides of the film-like adhesive, the resin films may be the same as or different from each other, and the combination of the resin films is not particularly limited.

The resin film may be composed of one layer (single layer) or a plurality of layers of two or more layers, and when composed of a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited.

The resin film may be a sheet made of only a resin as a constituent material, or may be a sheet made of a resin and components other than the resin as constituent materials and a resin as a main constituent material.

Examples of the resin that is a constituent material of the resin film include polyethylenes such as Low Density Polyethylene (LDPE), Linear Low Density Polyethylene (LLDPE), and High Density Polyethylene (HDPE); polyolefins other than polyethylene, such as polypropylene, polybutene, polybutadiene, polymethylpentene, and norbornene resins; ethylene copolymers (copolymers obtained using ethylene as a monomer) such as ethylene-vinyl acetate copolymers, ethylene- (meth) acrylic acid ester copolymers, and ethylene-norbornene copolymers; vinyl chloride-based resins (resins obtained using vinyl chloride as a monomer) such as polyvinyl chloride and vinyl chloride copolymers; polystyrene; a polycycloolefin; polyesters such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polyethylene isophthalate, polyethylene 2, 6-naphthalate, and wholly aromatic polyesters having an aromatic ring group in all the structural units; copolymers of two or more of said polyesters; poly (meth) acrylates; a polyurethane; a urethane acrylate; a polyimide; a polyamide; a polycarbonate; a fluororesin; a polyacetal; modified polyphenylene ether; polyphenylene sulfide; polysulfones; polyether ketones, and the like.

Examples of the resin include polymer alloys (polymer alloys) such as a mixture of the polyester and a resin other than the polyester. It is preferable that the amount of the resin other than polyester in the polymer alloy of the polyester and the resin other than polyester is smaller.

Examples of the resin include crosslinked resins obtained by crosslinking one or two or more of the above-exemplified resins; one or two or more kinds of modified resins such as ionomers of the above-exemplified resins are used.

The resin film may be a release film or a substrate described later. The substrate will be described in detail.

The release film may be, for example, a release film composed of a plurality of layers including a resin layer and a release treatment layer provided on one surface of the resin layer.

The release film can be produced by subjecting one surface of the resin layer to a release treatment.

The resin layer can be produced by molding or coating a resin composition containing a resin, and drying the resin composition as needed.

The resin as a constituent material of the resin layer is the same as the resin as a constituent material of the resin film.

The resin layer can be peeled off using various known peeling agents such as alkyd, silicone, fluorine, unsaturated polyester, polyolefin, wax, and the like.

The release agent is preferably an alkyd type, silicone type or fluorine type release agent in terms of heat resistance.

The resin layer may be composed of one layer (single layer) or a plurality of layers of two or more layers, and when composed of a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited.

As a laminate sheet in which the release film as a resin film is provided on both sides of the film-like adhesive, for example, a laminate sheet 109 shown in fig. 1 can be mentioned.

As a laminate sheet in which a resin film is provided only on one side of the film-like adhesive, for example, a laminate sheet 108 shown in fig. 2 can be given.

In the drawings subsequent to fig. 2, the same reference numerals as those in the already-described drawings are assigned to the same components as those shown in the already-described drawings, and detailed description thereof is omitted.

The laminate sheet 108 shown here is configured by providing a resin film 19 on the first surface 13a of the film-like adhesive 13.

The resin film 19 is the above-described resin film, and may be a release film (for example, the first release film 151 or the second release film 152 in fig. 1) or a substrate described later.

The thickness of the resin film may be arbitrarily set according to the purpose, and is not particularly limited.

The thickness of the resin film may be, for example, 10 to 200 μm.

The laminate sheet of the present embodiment is not limited to the laminate sheet shown in fig. 2, and may be a laminate sheet in which a part of the structure of the laminate sheet shown in fig. 2 is changed or deleted, or a laminate sheet in which another structure is further added to the above-described laminate sheet, within a range in which the effects of the present invention are not impaired. More specifically, as described below.

For example, the laminate sheet of the present embodiment may include nothing on the second surface of the film-like adhesive, or may include a jig adhesive layer for fixing the laminate sheet to a jig such as a ring frame in a region near the peripheral edge portion of the second surface of the film-like adhesive.

The pressure-sensitive adhesive layer for a jig may have, for example, a single-layer structure containing a pressure-sensitive adhesive component, or a multilayer structure in which layers containing a pressure-sensitive adhesive component are laminated on both surfaces of a sheet as a core material.

For example, when the laminated sheet is viewed from above the film-shaped adhesive side or the resin film side of the laminated sheet in a downward direction, the surface areas of the film-shaped adhesive and the resin film may be the same or substantially the same, and in the laminated sheet of the present embodiment, the surface area of the film-shaped adhesive may be smaller than the surface area of the resin film, and a part of the region of the resin film may be exposed. At this time, for example, at least the peripheral edge portion in the width direction of the resin film may be exposed without being covered with the film-like adhesive. The laminate sheet may have the adhesive layer for a jig on an exposed surface of the resin film.

The composite sheet 101 shown here is constructed in the following manner: the dicing sheet 10 includes a substrate 11 and an adhesive layer 12 provided on one surface (in this specification, sometimes referred to as a "first surface") 11a of the substrate 11, and the adhesive layer 12 is disposed between the substrate 11 and the film-like adhesive 13.

In other words, the composite sheet 101 is formed by sequentially laminating the base material 11, the adhesive layer 12, and the film-like adhesive 13 in the thickness direction thereof.

The surface (in this specification, sometimes referred to as "first surface") 10a on the film-like adhesive 13 side of the dicing sheet 10 is the same as the surface (in this specification, sometimes referred to as "first surface") 12a of the adhesive layer 12 on the side opposite to the substrate 11 side.

The composite sheet 101 further includes a release film 15 on the film-like adhesive 13.

In the composite sheet 101, the adhesive layer 12 is laminated on the first surface 11a of the base material 11, the film-like adhesive 13 is laminated on the entire or substantially entire first surface 12a of the adhesive layer 12, and the release film 15 is laminated on the entire or substantially entire first surface 13a of the film-like adhesive 13.

The cutting blade 10 may be a known cutting blade.

The substrate 11 and the adhesive layer 12 in the cut sheet 10 will be described in this order.

The base material 11 in the dicing sheet 10 is in a sheet or film form, and examples of the constituent material include various resins. Examples of the resin that is a constituent material of the dicing sheet 10 include the same resin as that which is a constituent material of the resin film in the laminate sheet.

The resin constituting the base material may be one kind only, or two or more kinds, and in the case of two or more kinds, the combination and ratio thereof may be arbitrarily selected.

The substrate may be composed of one layer (single layer) or a plurality of layers of two or more layers, and when composed of a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited.

The thickness of the substrate 11 is preferably 50 to 300 μm, and more preferably 60 to 150 μm. By setting the thickness of the base material 11 to the above range, the flexibility of the composite sheet 101 and the adhesiveness to the object to be adhered are further improved.

Here, the "thickness of the substrate" refers to the thickness of the entire substrate, and for example, the thickness of the substrate composed of a plurality of layers refers to the total thickness of all the layers constituting the substrate.

The substrate 11 is preferably a substrate having high thickness accuracy, that is, a substrate in which thickness unevenness is suppressed at any portion. Among the above-mentioned constituent materials, examples of materials that can be used to form such a base material with high thickness accuracy include polyethylene, polyolefins other than polyethylene, polyethylene terephthalate, ethylene-vinyl acetate copolymers, and the like.

The base material 11 may contain various known additives such as a filler, a colorant, an antistatic agent, an antioxidant, an organic lubricant, a catalyst, and a softener (plasticizer) in addition to the main constituent material such as the resin.

The base material 11 may be transparent or opaque, may be colored according to the purpose, or may be vapor-deposited with another layer.

In order to improve the adhesion between the substrate 11 and another layer (here, the adhesive agent layer 12) or the like provided thereon, the substrate 11 may be one having a surface subjected to an embossing treatment such as a blast treatment or a solvent treatment, or an oxidation treatment such as a corona discharge treatment, an electron beam irradiation treatment, a plasma treatment, an ozone/ultraviolet irradiation treatment, a flame treatment, a chromic acid treatment, or a hot air treatment.

The substrate 11 may be a primer treated (primer treated) substrate.

Further, the substrate 11 may have: an antistatic coating; a layer for preventing the adhesion of the substrate 11 to other sheets, a layer for preventing the adhesion of the substrate 11 to the adsorption plate, or the like when the composite sheet is stacked and stored.

The substrate 11 can be manufactured by a known method. For example, the resin-containing substrate 11 can be produced by molding a resin composition containing the resin.

The adhesive layer 12 in the dicing sheet 10 is in a sheet or film form and contains an adhesive.

Examples of the adhesive include adhesive resins such as acrylic resins, urethane resins, rubber resins, silicone resins, epoxy resins, polyvinyl ethers, polycarbonates, and ester resins, and acrylic resins are preferred.

In the present specification, the term "adhesive resin" includes both a resin having adhesive properties and a resin having adhesive properties. For example, the adhesive resin includes not only a resin having adhesiveness itself but also a resin exhibiting adhesiveness by being used together with other components such as an additive, a resin exhibiting adhesiveness by the presence of a trigger (trigger) such as heat or water, and the like.

The adhesive layer 12 may be composed of one layer (single layer) or a plurality of layers of two or more layers, and in the case of being composed of a plurality of layers, these plurality of layers may be the same as or different from each other, and the combination of these plurality of layers is not particularly limited.

The thickness of the adhesive layer 12 is not particularly limited, but is preferably 1 to 100. mu.m, more preferably 1 to 60 μm, and particularly preferably 1 to 30 μm.

The "thickness of the adhesive agent layer" refers to the thickness of the entire adhesive agent layer, and for example, the thickness of the adhesive agent layer composed of a plurality of layers refers to the total thickness of all the layers constituting the adhesive agent layer.

The adhesive layer 12 may be formed using an energy ray-curable adhesive, or may be formed using a non-energy ray-curable adhesive. That is, the adhesive layer 12 may be either energy ray-curable or non-energy ray-curable. The energy ray-curable adhesive layer 12 can easily adjust physical properties before and after curing. For example, by curing the energy ray-curable adhesive layer 12, the adhesive force to the object to which it is attached can be easily adjusted.

The adhesive layer 12 can be formed using an adhesive composition containing an adhesive. For example, the adhesive agent layer can be formed at a target site by applying the adhesive composition to a surface to be formed with the adhesive agent layer 12 and drying the same as necessary. The content ratio of the components that do not vaporize at normal temperature in the adhesive composition is generally the same as the content ratio of the components in the adhesive layer 12. In the present specification, "normal temperature" means a temperature at which cooling or heating is not particularly performed, that is, a normal temperature, and includes, for example, a temperature of 15 to 25 ℃.

The adhesive composition may be applied by a known method, and examples thereof include a method using various coating machines such as a knife coater, a blade coater, a bar coater, a gravure coater, a roll coater, a curtain coater, a die coater, a knife coater, a screen coater, a meyer bar coater, and a kiss coater.

When the adhesive layer 12 is provided on the substrate 11, for example, the adhesive composition may be applied to the substrate 11 and dried as necessary, thereby laminating the adhesive layer 12 on the substrate 11. In addition, when the adhesive layer 12 is provided on the substrate 11, for example, the adhesive layer 12 may be laminated on the substrate 11 by applying an adhesive composition to a release film and drying it as necessary to form the adhesive layer 12 on the release film and bonding an exposed surface of the adhesive layer 12 to one surface (here, the first surface 11a) of the substrate 11. The release film in this case may be removed at any timing in the manufacturing process or the use process of the composite sheet 101.

When the adhesive layer 12 is energy ray-curable, examples of the energy ray-curable adhesive composition include: an adhesive composition (I-1) comprising a non-energy-ray-curable adhesive resin (I-1a) (hereinafter, may be abbreviated as "adhesive resin (I-1 a)") and an energy-ray-curable compound; an adhesive composition (I-2) comprising an energy ray-curable adhesive resin (I-2a) having an unsaturated group introduced into a side chain of the adhesive resin (I-1a) (hereinafter, may be abbreviated as "adhesive resin (I-2 a)"); and an adhesive composition (I-3) containing the adhesive resin (I-2a) and an energy ray-curable compound.

When the adhesive layer 12 is non-energy ray-curable, examples of the non-energy ray-curable adhesive composition include the adhesive composition (I-4) containing the adhesive resin (I-1 a).

The film-like adhesive 13 has the above-described light transmittance. For example, at least one of the first surface 13a and the second surface 13b of the film-like adhesive 13 contains substantially no aromatic compound.

The film-like adhesive 13 preferably has a thickness of 10 to 40 μm.

The release film 15 is the same as the first release film 151 or the second release film 152 shown in fig. 1.

The composite sheet of the present embodiment is not limited to the composite sheet 101, and the release film (for example, the release film 15 shown in fig. 3) may have any configuration, and the composite sheet of the present embodiment may or may not have a release film.

The composite sheet 101 is used in the following manner: in a state where the release film 15 is removed, an object (for example, a circuit formation surface of a chip) is attached to the first surface 13a of the film-like adhesive 13.

The composite sheet of the present embodiment is not limited to the composite sheet shown in fig. 3, and may be a composite sheet in which a part of the composite sheet shown in fig. 3 is modified or deleted, or a composite sheet in which another configuration is further added to the composite sheet described above, within a range in which the effects of the present invention are not impaired. More specifically, as described below.

Although the composite sheet having the dicing sheet and the dicing sheet constituted by laminating the base material and the adhesive layer has been described above, the composite sheet of the present embodiment may have a dicing sheet constituted only by the base material. That is, the composite sheet may be configured as follows: the adhesive film is provided with a base material and a film-shaped adhesive provided on one surface of the base material, and no adhesive layer is arranged between the base material and the film-shaped adhesive. As the composite sheet, a composite sheet in which the base material (for example, the base material 11 shown in fig. 3) is the resin film 19 in the laminate sheet 108 shown in fig. 2 can be cited.

Although the composite sheet including the dicing sheet and the dicing sheet formed by laminating the substrate and the adhesive agent layer has been described above, the composite sheet of the present embodiment may include a dicing sheet formed by including the substrate, the adhesive agent layer, and an intermediate layer other than the substrate and the adhesive agent layer. The dicing sheet includes, for example, a substrate, an adhesive layer provided on one surface of the substrate, and an intermediate layer provided on a surface of the adhesive layer opposite to the substrate side. When the dicing sheet is used, an intermediate layer is disposed between the adhesive layer and the film-like adhesive agent in the composite sheet.

For example, the composite sheet of the present embodiment may be provided with the release film only on the first surface of the film-shaped adhesive, or may be provided with a pressure-sensitive adhesive layer for a jig for fixing the composite sheet to a jig such as a ring frame in a region near the peripheral edge portion of the first surface of the film-shaped adhesive.

The adhesive layer for a clip in this case is the same as the adhesive layer for a clip described above.

For example, when the composite sheet is viewed from above the film-shaped adhesive agent side or the dicing sheet side of the composite sheet in a downward direction, the surface areas of the film-shaped adhesive agent and the dicing sheet may be the same or substantially the same, and in the composite sheet of the present embodiment, the surface area of the film-shaped adhesive agent may be smaller than the surface area of the dicing sheet, and a partial region of the dicing sheet (for example, an adhesive agent layer) may be exposed. At this time, for example, at least the widthwise peripheral edge portion of the dicing sheet may be exposed without being covered with the film-like adhesive. The composite sheet may have the adhesive layer for a jig on an exposed surface of the dicing sheet.

The configuration of the composite sheet is illustrated above as the substrate, the adhesive layer, the intermediate layer, the film-like adhesive, the adhesive layer for a jig, and the release film, but the composite sheet of the present embodiment may have another layer not belonging to any of these layers.

When the composite sheet includes the other layer, the arrangement position thereof is not particularly limited.

In the composite sheet of the present embodiment, the size and shape of each layer can be arbitrarily selected according to the purpose.

Method of using laminate (film-like adhesive)

Laminate and method for producing same

The film-like adhesive in the laminate sheet of the present embodiment can be used as a film for adhering the light-transmissive cover to a circuit-formed surface of a chip such as a sensor, for example.

More specifically, by using the film-shaped adhesive, a laminate including a chip, a film-shaped adhesive provided on a circuit formation surface of the chip, and a light-transmitting cover provided on a surface of the film-shaped adhesive opposite to the chip side can be manufactured. In the laminate, either one or both of the surface on the chip side and the surface on the transparent cover side of the film-like adhesive are substantially free of aromatic compounds, and preferably both surfaces are substantially free of aromatic compounds.

Fig. 4 is a cross-sectional view schematically showing an example of the laminate.

The laminate 801 shown here is configured to include the die 8, the film-like adhesive 13 provided on the circuit forming surface 8a of the die 8, and the light-transmissive cover 7 provided on the surface (first surface) 13a of the film-like adhesive 13 opposite to the die 8 side.

In the laminate 801, the surfaces of the die 8 and the film-like adhesive 13 that face each other, that is, the circuit-forming surface 8a of the die 8 and the surface (second surface) 13b of the film-like adhesive 13 on the die 8 side are in direct contact with each other. The opposing surfaces of the film-shaped adhesive 13 and the light-transmitting cover 7, that is, the first surface 13a of the film-shaped adhesive 13 and the surface (in this specification, it may be referred to as "second surface") 7b of the light-transmitting cover 7 on the film-shaped adhesive 13 side are in direct contact with each other.

Thus, the laminate 801 is configured as follows: the chip 8, the film-like adhesive 13, and the light-transmissive cover 7 are sequentially stacked in the thickness direction thereof, and the circuit-forming surface 8a of the chip 8 is disposed on the film-like adhesive 13 side.

The film-like adhesive 13 in the laminate 801 is, for example, a film-like adhesive from which the first release film 151 and the second release film 152 in the laminate sheet 109 shown in fig. 1 are removed, or a film-like adhesive from which the resin film 19 in the laminate sheet 108 shown in fig. 2 is removed.

In the laminate 801, either one or both of the first surface 13a and the second surface 13b of the film-like adhesive 13 is substantially free of an aromatic compound, and preferably both surfaces are substantially free of an aromatic compound.

In fig. 4, the circuit of the chip 8 is not shown. Note that reference numeral 7a denotes a surface (in this specification, may be referred to as a "first surface") of the light-transmissive cover 7 opposite to the second surface 7 b.

The light-transmissive cover 7 protects the circuit-formed surface 8a of the chip 8, and the outside of the light-transmissive cover 7 on the side of the second surface 7b can be recognized from the outside of the light-transmissive cover 7 on the side of the first surface 7 a.

On the other hand, the film-like adhesive 13 has the above-described light transmittance. Therefore, in the laminate 801, visual information existing on the circuit-formation-surface 8a of the chip 8 can be recognized through the light-transmissive cover 7 and the film-like adhesive 13 (with the light-transmissive cover 7 and the film-like adhesive 13 interposed therebetween).

Further, as described above, the film-like adhesive 13 has high light transmittance before and after heating, and coloring is suppressed. Therefore, the laminated body 801 can recognize visual information on the chip 8 stably and with high accuracy.

As the chip 8, for example, a fingerprint sensor can be used, and in this case, the laminated body 801 can be used as a fingerprint sensor module.

The laminate using the film-shaped adhesive is not limited to the laminate shown in fig. 4, and may be a laminate in which a part of the structure of the laminate shown in fig. 4 is changed or deleted, or a laminate in which another structure is further added to the laminate described above, within a range in which the effects of the present invention are not impaired.

The laminate can be produced, for example, by bonding a circuit-forming surface of a chip to one surface (second surface) of the film-like adhesive and bonding a light-transmissive cover to the other surface (first surface) of the film-like adhesive.

Method of using a compact

Laminate and method for producing same

The composite sheet of the present embodiment can be used by a known method similar to that of the composite sheet.

Fig. 5 is a sectional view for schematically illustrating one example of a use method of the composite sheet of the present embodiment. A case where the composite sheet 101 shown in fig. 3 is used will be described.

As shown here, the composite sheet 101 is used in the following manner: after the release film 15 is removed, the first surface 13a of the film-like adhesive 13 is attached to the circuit-formed surface 8a of the chip 8.

After the composite sheet 101 is attached to the chip 8, for example, the chip 8 is cut and singulated (singulation), and the film-like adhesive 13 is cut along the outer periphery of the singulated chip 8. In this case, the singulation of the chips 8 and the cutting of the film-like adhesive 13 may be performed by a known method, and for example, the singulation and the cutting may be performed simultaneously, or the chips 8 may be singulated and then the film-like adhesive 13 may be cut separately.

Next, the singulated chips 8 are separated from the dicing sheet 10 together with the cut film-like adhesive 13 and picked up. When the adhesive layer 12 is energy ray-curable, the adhesive layer 12 is energy ray-cured to lower the adhesion to the film-like adhesive 13, and then pickup is performed, whereby pickup can be performed more easily.

Next, the laminate (for example, the laminate 801 shown in fig. 4) can be produced by bonding a light-transmitting cover to the second surface of the film-shaped adhesive 13 after cutting and picking up.

In the laminate, either one or both of the first face and the second face of the film-like adhesive is substantially free of an aromatic compound, and preferably both faces are substantially free of an aromatic compound.

Here, the case where the film-shaped adhesive in the composite sheet is bonded to the chip, and after the chip is singulated and the film-shaped adhesive is cut, the light-transmitting cover is bonded to the cut film-shaped adhesive, but the order of bonding the chip and the light-transmitting cover to the film-shaped adhesive may be reversed. That is, the laminate (for example, laminate 801 shown in fig. 4) may also be produced by: the first surface of the film-like adhesive is attached to the second surface of the light-transmitting cover, the light-transmitting cover is cut and singulated, the film-like adhesive is cut, the adhesive layer is cured by energy rays as needed, the singulated light-transmitting cover is separated from the cut sheet together with the cut film-like adhesive and picked up, and then a chip is attached to the cut and picked up first surface of the film-like adhesive.

Examples

The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited to the examples shown below.

< raw Material for preparation of adhesive composition >

The raw materials used for preparing the adhesive compositions in the present examples and comparative examples are shown below.

[ acrylic resin (a) ]

(a) -1: an acrylic resin (weight average molecular weight 800000, glass transition temperature 6 ℃) obtained by copolymerizing methyl acrylate (85 parts by mass) and 2-hydroxyethyl acrylate (15 parts by mass).

(a) -2: an acrylic resin (weight average molecular weight 800000, glass transition temperature 9 ℃) obtained by copolymerizing methyl acrylate (95 parts by mass) and 2-hydroxyethyl acrylate (5 parts by mass).

[ epoxy Compound (b1) ]

(b1) -1: an acryl-added cresol novolak type epoxy resin ("CNA 147" manufactured by Nippon Kayaku Co., Ltd., number average molecular weight of 2100, and the content of unsaturated groups and the content of epoxy groups being equal in amount)

(b1) -2: hydrogenated bisphenol A epoxy resin ("EPOLIGHT 4000" manufactured by KYOEISHA CHEMICAL Co., LTD., epoxy equivalent weight of 310-340 g/eq)

(b1) -3: hydrogenated bisphenol type epoxy resin ("YX 8000", epoxy equivalent 205g/eq manufactured by Mitsubishi Chemical Corporation)

(b1) -4: triazine type alicyclic epoxy compound ("TEPIC-PAS B22" manufactured by Nissan Chemical Corporation, epoxy equivalent 180 to 200g/eq)

(b1) -5: triazine type alicyclic epoxy compound ("TEPIC VL" manufactured by Nissan Chemical Corporation, epoxy equivalent of 125 to 145g/eq)

(b1) -6: bisphenol A epoxy resin ("jER 828" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 184-194 g/eq)

(b1) -7: dicyclopentadiene type epoxy resin ("XD-1000-L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 248g/eq)

(b1) -8: triphenylene-type epoxy resin ("EPPN-502H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 158 to 178g/eq)

[ phenol resin (b2) ]

(b2) -1: aralkyl type phenol resin ("HE 100C-10" manufactured by Air Water Chemical Co., Ltd.)

[ Filler (d) ]

(d) -1: spherical silica modified with methacryloyl group ("YA 050C-MJE" manufactured by Admatechs corporation, average particle diameter 50nm)

(d) -2: epoxy-modified spherical silica ("YA 050C-MKK", average particle diameter 50nm, manufactured by Admatechs Co., Ltd.)

[ crosslinking agent (f) ]

(f) -1: trimethylol propane tolylene diisocyanate trimer adduct ("CORONATE L" manufactured by TOSOH CORPORATION)

(f) -2: isophorone diisocyanate trimer adduct of trimethylolpropane ("D-140N" manufactured by Mitsui Chemicals, Inc.)

(f) -3: xylylene diisocyanate trimer adduct of trimethylolpropane ("D-110N" manufactured by Mitsui Chemicals, Inc.)

(f) -4: hexamethylene diisocyanate trimer adduct of trimethylolpropane (TOYOCHEM CO., LTD, "Bxx 4773")

[ phosphorus-based antioxidant (z) ]

(z) -1: bis (decyl) pentaerythritol diphosphite (JOHOKU CHEMICALCO., manufactured by LTD, "JPE-10", aliphatic phosphites)

(z) -2: tris (2-ethylhexyl) phosphite (JOHOKU CHEMICALCO., manufactured by LTD, "JP-308E", aliphatic phosphite)

[ example 1]

Preparation of film-like adhesive

< preparation of adhesive composition >

An acrylic resin (a) -1(44.3 parts by mass), an epoxy compound (b1) -2(40 parts by mass), a filler (d) -2(15 parts by mass), a crosslinking agent (f) -4(0.2 part by mass), and a phosphorus antioxidant (z) -1(0.5 part by mass) were dissolved or dispersed in methyl ethyl ketone, and stirred at 23 ℃. The amounts of the components other than methyl ethyl ketone to be blended are the amounts of the target compounds not including the solvent component.

< production of film-shaped adhesive >

Using a release film (SP-PET 381031 manufactured by linetec Corporation, "thickness 38 μm") obtained by peeling one surface of a polyethylene terephthalate (PET) film by silicone treatment, the adhesive composition obtained above was applied to the release-treated surface of the release film, and heated and dried at 100 ℃ for 2 minutes, thereby forming a film-shaped adhesive having a thickness of 20 μm, and an adhesive sheet was obtained in which the release film and the film-shaped adhesive were laminated in the thickness direction thereof.

Evaluation of film-shaped adhesive

< determination of shear Strength >

A dicing sheet ("Adwill D-678" manufactured by linec Corporation) was attached to a 6-inch silicon wafer (thickness 350 μm) using a tape mounter ("Adwill RAD2500 m/12" manufactured by linec Corporation) at an attachment temperature of 23 ℃ and an attachment speed of 20mm/s, and the laminate of the dicing sheet and the silicon wafer was fixed to a ring frame.

Next, a cutting was performed by using a cutting device ("DFD 6362" manufactured by DISCO Corporation) and a cutting blade ("NBC-ZH 2050-SE27 HECC" manufactured by DISCO Corporation) at a blade rotation speed of 30000rpm and a cutting speed of 40mm/s, to obtain a plurality of silicon chips (hereinafter, sometimes referred to as "silicon chip groups") each having a size of 2mm × 2 mm. The dicing sheet was formed by laminating a base material and an adhesive layer, and when dicing was performed, the dicing sheet was cut with a dicing blade to a region having a depth of 20 μm of the base material.

Next, the obtained adhesive sheet was heated to 60 ℃ and attached to the obtained silicon chip group with a film-like adhesive in the adhesive sheet. At this time, the adhesive sheet is attached to a surface (exposed surface) of the silicon chip group, which is opposite to the side to which the dicing sheet is attached. Then, the bonded adhesive sheet was cut along the outer periphery of the silicon chip.

As described above, a laminate having a size of 2mm × 2mm was obtained in which a dicing sheet, a silicon chip, and an adhesive sheet were laminated in this order in the thickness direction.

Next, the release film was removed from the film-like adhesive in the laminate, and the exposed surface of the newly produced film-like adhesive was attached to the surface of a copper plate having a size of 30mm × 30mm and a thickness of 300 μm using a manual die bonder. At this time, the film-shaped adhesive was pressed to the copper plate while being heated to 125 ℃ with a force of 2.45N (250gf), thereby being attached to the copper plate. Further, the bonded product was heated at 175 ℃ for 5 hours to obtain a test piece.

Next, a force was applied to the film-like adhesive and the silicon chip on the side of the test piece in a direction parallel to the attaching face of the film-like adhesive to the copper plate using a multifunctional weld strength tester ("DAGE 4000" manufactured by Nordson Advanced Technology k.k.) at a temperature condition of 23 ℃ and at a speed of 200 μm/s using a shear tool (shear tool). Then, the maximum value of the force applied until the film-like adhesive was broken was confirmed, and this was used as the shear strength (N/2mm □) of the film-like adhesive. The results are shown in Table 1.

< measurement of Linear transmittance before heating of light (400 to 800nm) >

The film-like adhesive obtained above was attached to one surface of a glass slide (thickness: 0.9mm) while heating at 40 ℃. The film-like adhesive is not subjected to heat treatment for a period from immediately after the production to the time of the attachment.

Next, a portion of the attached film-shaped adhesive that has emerged from the glass slide glass is cut to obtain a test piece (hereinafter referred to as a "pre-heating test piece") in which the film-shaped adhesive and the glass slide glass having the same size are laminated in the thickness direction thereof with the peripheral edge portions of the two aligned.

The glass slide used for the preparation of the pre-heating test piece was measured for linear transmittance (hereinafter referred to as "reference linear transmittance") of light (400 to 800nm) using a spectrophotometer ("UV-3101 PC" manufactured by Shimadzu Corporation) before the preparation of the pre-heating test piece.

The linear transmittance of light (400 to 800nm) was measured for the test piece before heating obtained in the same manner as above.

The measured value of the reference linear transmittance at the same wavelength was subtracted from the measured value of the linear transmittance of light (400 to 800nm) at each wavelength of the test piece before heating, and the obtained value was used as the linear transmittance of the film-shaped adhesive to light (400 to 800nm) before heating (i.e., the linear transmittance before heating). The results are shown in Table 1.

< measurement of Linear transmittance of light (400 to 800nm) after heating >

The test piece after the linear transmittance before heating of the above measurement light (400 to 800nm) was heated at 260 ℃ for 10 minutes using an electric furnace.

Subsequently, the heated test piece was allowed to cool to the same temperature as room temperature.

Then, the linear transmittance of light (400 to 800nm) was measured with respect to the test piece after the heating and cooling (hereinafter referred to as "test piece after heating") by the same method as the test piece before heating.

The measured value of the reference linear transmittance at the same wavelength was subtracted from the measured value of the linear transmittance of light (400 to 800nm) at each wavelength of the test piece after heating, and the obtained value was used as the linear transmittance of the film-shaped adhesive to light (400 to 800nm) after heating (i.e., the linear transmittance after heating). The results are shown in Table 1.

< evaluation of fingerprint identifiability before heating based on RGB >

A digital camera ("IXY 650" manufactured by Canon Marketing Japan inc., ltd.) was placed in front of the finger pad of the left index finger, and the distance between the surface of the finger pad of the left index finger and the surface of the camera lens was adjusted to 50mm, and in this state, image data of the fingerprint of the left index finger (hereinafter referred to as "reference image data") was obtained in macro mode.

The left index finger and the digital camera were maintained in a positional relationship, and the pre-heating test piece was further positioned between the abdomen of the left index finger and the digital camera. At this time, the pre-heating test piece was disposed so that a straight line connecting the finger pad of the left index finger and the digital camera was orthogonal to the exposed surface of the glass slide glass (i.e., the surface opposite to the sticking surface of the film-like adhesive) in the pre-heating test piece, and the exposed surface was on the digital camera side. Under this condition, the same method as that used for obtaining the reference image data is used to obtain the image data of the fingerprint of the left index finger (hereinafter referred to as "before-heating transmission image data") in the macro mode.

The reference imaging data and the transmission imaging data before heating obtained as described above are developed using drawing software ("Paint" manufactured by microsoft corporation), and the colors of the ridges and valleys of the fingerprint are extracted from the respective data and digitized with RGB.

The R value of the ridge of the fingerprint obtained from the reference captured image data is subtracted from the R value of the ridge of the fingerprint obtained from the pre-heating transmission captured image data, and the resulting value is used as the R value of the ridge of the fingerprint at the time of pre-heating evaluation. The G value and B value of the ridge of the fingerprint at the time of evaluation before heating were obtained by the same method as above.

In the same manner as described above, the R values of the valleys of the fingerprint obtained from the reference imaging data are subtracted from the R values of the valleys of the fingerprint obtained from the pre-heating transmission imaging data, and the obtained values are used as the R values of the valleys of the fingerprint at the time of the pre-heating evaluation. The G and B values of the valleys of the fingerprint at the time of evaluation before heating were determined by the same method as above.

Further, an absolute value of a difference between the R value of the ridge portion and the R value of the valley portion (hereinafter, sometimes referred to as "absolute value Δ R") is calculated, an absolute value of a difference between the G value of the ridge portion and the G value of the valley portion (hereinafter, sometimes referred to as "absolute value Δ G") is calculated, and an absolute value of a difference between the B value of the ridge portion and the B value of the valley portion (hereinafter, sometimes referred to as "absolute value Δ B") is calculated.

From these calculated values, fingerprint identification of the film-shaped adhesive before heating based on RGB was evaluated in accordance with the following criteria. The results are shown in Table 1.

(evaluation criteria)

A: at least one of the absolute value Δ R, the absolute value Δ G, and the absolute value Δ B is 10 or more.

B: the absolute value Δ R, the absolute value Δ G, and the absolute value Δ B are all less than 10, and at least one of the absolute value Δ R, the absolute value Δ G, and the absolute value Δ B is 5 or more.

C: the absolute value delta R, the absolute value delta G and the absolute value delta B are all smaller than 5.

< evaluation of fingerprint recognizability after heating based on RGB >

The fingerprint identification properties of the RGB-based heated film-shaped adhesive were evaluated in the same manner as in the "evaluation of fingerprint identification properties before heating" described above, except that the heated test piece was used instead of the test piece before heating.

More specifically, in the present evaluation, "transmission imaging data after heating" is obtained instead of the transmission imaging data before heating. Further, using the post-heating transmission imaging data, the R value, G value, and B value of the ridge portion of the fingerprint at the time of post-heating evaluation are obtained instead of the R value, G value, and B value of the ridge portion of the fingerprint at the time of pre-heating evaluation, and the R value, G value, and B value of the valley portion of the fingerprint at the time of post-heating evaluation are obtained instead of the R value, G value, and B value of the valley portion of the fingerprint at the time of pre-heating evaluation. Further, from these R, G and B values, an absolute value Δ R, an absolute value Δ G and an absolute value Δ B at the time of evaluation after heating are calculated instead of the absolute value Δ R, the absolute value Δ G and the absolute value Δ B at the time of evaluation before heating. The results are shown in Table 1.

< evaluation of fingerprint identifiability before heating based on naked eye >

5 observers were randomly selected, and the fingerprints were visually observed by 1 observer per one observer by the following method.

That is, 1 observer was placed in front of the finger pulp of the left index finger, and the distance between the surface of the finger pulp of the left index finger and the eyes of the observer was adjusted to 150mm, and the fingerprint of the left index finger was directly observed visually in this state.

The left index finger and the observer were kept in the arrangement relationship, and the pre-heat test piece was further arranged between the abdomen of the left index finger and the observer. The arrangement of the test piece before heating in this case is the same as that in the above-described "evaluation of fingerprint identification before heating based on RGB". Under these conditions, the fingerprint of the left index finger was visually observed through the pre-heating test piece in the same manner as in the above direct visual observation.

With this method, all of 5 observers were allowed to visually observe the fingerprint directly and the fingerprint through the test piece before heating, and the fingerprint identifiability of the film-like adhesive before heating by the naked eye was evaluated based on the following criteria based on the comparison between the observation result of the fingerprint through the test piece before heating and the observation result of the fingerprint through the direct visual observation. The results are shown in Table 1. The numerical values in parentheses in the column of "fingerprint identifiability" in table 1 represent "the number of observers (persons) who judged that there was no difference in the observation result of the fingerprint".

A: all 5 observers determined that there was no difference in the fingerprint observation results.

B: of the 5 observers, 4 were judged to have no difference in the observation results of the fingerprints.

C: among 5 observers, 2 or more of them judged that the fingerprints were different in color from each other, and the observation results were different.

< evaluation of fingerprint identifiability after heating based on naked eye >

The fingerprint identification property of the film-shaped adhesive after heating by the naked eye was evaluated in the same manner as in the above-mentioned "evaluation of fingerprint identification property before heating by the naked eye" except that the test piece after heating was used instead of the test piece before heating. The results are shown in Table 1.

< evaluation of Presence and absence of FT-IR-based aromatic Compound >

One surface of the obtained film adhesive was subjected to ATR method using a Fourier transform infrared/near infrared spectrometer ("Spectrum 100" manufactured by Perkinelmer corporation) at a wave number of 4000 to 400cm^-1FT-IR measurement was conducted in the range of (1). At a wave number of 3050-2990 cm^-1In the above range, the presence or absence of an inflection point in a curve showing the transmittance was confirmed, and the presence or absence of an aromatic compound in the surface of the film-like adhesive was confirmed. The results are shown in Table 1. "FT-IR (3050-2990 cm) of Table 1^-1) In the column of inflection point, "there" is a value in parentheses indicating "the number of waves (cm) at which the inflection point was confirmed^-1)". Fig. 6 shows the spectrum data obtained at this time.

Production and evaluation of film-shaped adhesive

[ examples 2 to 4]

A film-shaped adhesive was produced and evaluated in the same manner as in example 1, except that either one or both of the kind and the blending amount of the blending components in the preparation of the adhesive composition were changed so that the kind and the content of the components contained in the adhesive composition were as shown in table 1. The results are shown in Table 1.

[ comparative examples 1 to 3]

Film-shaped adhesives were produced and evaluated in the same manner as in example 1, except that either one or both of the types and the blending amounts of the components to be blended in the preparation of the adhesive compositions were changed so that the types and the contents of the components to be included in the adhesive compositions were as shown in table 2. The results are shown in Table 2.

In addition, the statement "-" in the column of the component contained in tables 1 and 2 means that the adhesive composition does not contain the component.

[ Table 1]

[ Table 2]

From the above results, it is clear that in examples 1 to 4, both the film-shaped adhesive before heating at 260 ℃ and the film-shaped adhesive after heating at 260 ℃ have high light transmittance, coloration is suppressed, and fingerprint visibility is high. In examples 1 to 4, the film-like adhesive had a linear transmittance to light (400 to 800nm) of 95% or more (95 to 98%) before heating at 260 ℃ and had a linear transmittance to light (400 to 800nm) of 86% or more (86 to 95%) after heating at 260 ℃.

In examples 1 to 4, the shear strength of the film-like adhesive was 48N/2mm □ or more (48 to 80N/2mm □), and the adhesive strength of the film-like adhesive was sufficiently high.

Presume that: in examples 1 to 4, since the film-shaped binder contains the phosphorus-based antioxidant (z) and all components including the phosphorus-based antioxidant (z) do not have an aromatic cyclic group, coloring due to heating is suppressed.

In examples 1 to 4, the wave number was 3050 to 2990cm^-1In the curve showing the transmittance, a clear inflection point, which cannot be referred to as noise, was not observed, and it was shown that the aromatic compound was not substantially present on the measurement surface of the film-like adhesive, and the result was consistent with the use of the above components. In FIG. 6, the results of examples 3 to 4 are not shown in order to make it easy to observe the curves showing the transmittance, but the shapes of the curves of examples 3 to 4 are also the same as those of examples 1 to 2.

On the other hand, in comparative examples 1 to 3, the light transmittance of the film-like adhesive after heating at 260 ℃ was low, and the coloring was not suppressed, and the fingerprint recognition property was low. In comparative examples 1 to 3, the linear transmittance of the film-like adhesive to light (400 to 800nm) was 16% or less after heating at 260 ℃.

Presume that: in comparative examples 1 and 3, although the film-shaped adhesive contains the phosphorus-based antioxidant (z), the epoxy compound (b1), the phenol resin (b2), and the crosslinking agent (f) all have aromatic cyclic groups, and thus coloring by heating is not suppressed. As can be seen from FIG. 5, in comparative examples 1 and 3, the wave number is 3050 to 2990cm^-1In the curve showing the transmittance, a clear inflection point, which cannot be referred to as noise, was observed, indicating that an aromatic compound was present on the measurement surface of the film-like adhesive. The results were in accordance with the use of the above-mentioned components.

In comparative example 2, although the film-like adhesive before heating at 260 ℃ had high light transmittance and suppressed coloring, it is assumed that coloring due to heating was not suppressed because the film-like adhesive did not contain any antioxidant such as the phosphorus-based antioxidant (z) and the epoxy compound (b1), the phenol resin (b2) and the crosslinking agent (f) all have an aromatic cyclic group. As can be seen from FIG. 5, in comparative example 2, the wave number is 3050 to 2990cm^-1In the range of (1), a clear inflection point was observed in the curve showing the transmittance, indicating that an aromatic compound was present on the measurement surface of the film-shaped adhesive. It is composed ofThe results were in accordance with the use of the above-mentioned components.

Further, in comparative example 2, the shear strength of the film-like adhesive was 45N/2mm □, and the adhesive strength of the film-like adhesive was weaker than that of examples 1 to 4.

Industrial applicability

The present invention can be used as an adhesive in manufacturing or processing various components constituting an electronic device.

Description of the reference numerals

101: a composite sheet; 108. 109: a laminate sheet; 10: cutting the slices; 11: a substrate; 11 a: a first side of the substrate; 12: an adhesive layer; 13: a film-like adhesive; 13 a: a first side of a film-like adhesive; 13 b: a second side of the film-like adhesive; 151: a first release film; 152: a second release film; 19: a resin film; 7: a light-transmitting cover; 8: a chip; 8 a: a circuit forming surface of the chip; 801: a laminate.

Claims

1. A film-like adhesive used for bonding a circuit-formed surface of a chip to a light-transmitting cover,

at least one surface of the film-like adhesive is substantially free of aromatic compounds.

2. The film-like adhesive according to claim 1,

the film-like adhesive has a linear transmittance of 90% or more for light having a wavelength of 400 to 800nm before heating at 260 ℃,

after heating at 260 ℃ for 10 minutes, the film-like adhesive has a linear transmittance of 85% or more for light having a wavelength of 400 to 800nm,

the film-shaped adhesive has a thickness of 10 to 40 μm.

3. The film-shaped adhesive according to claim 1 or 2, wherein the film-shaped adhesive contains an aliphatic epoxy compound.

4. The film-like adhesive according to any one of claims 1 to 3, which contains an aliphatic phosphite as an antioxidant.

5. The film-like adhesive according to any one of claims 1 to 4,

the film-like adhesive contains an acrylic resin and an aliphatic polyisocyanate crosslinking agent,

the acrylic resin has a functional group that can bond with the crosslinking agent.

6. A laminate comprising the film-shaped adhesive according to any one of claims 1 to 5 and a resin film provided on one surface of the film-shaped adhesive.

7. A composite sheet comprising the film-shaped adhesive according to any one of claims 1 to 5 and a dicing sheet provided on one surface of the film-shaped adhesive,

the dicing sheet comprises a base material and an adhesive layer provided on one surface of the base material,

the adhesive layer is disposed between the substrate and the film-shaped adhesive.

8. A method for producing a laminate, wherein a circuit-forming surface of a chip is bonded to one surface of the film-like adhesive according to any one of claims 1 to 5, and a light-transmitting cover is bonded to the other surface of the film-like adhesive, thereby obtaining a laminate in which the chip, the film-like adhesive, and the light-transmitting cover are sequentially laminated.