KR20250065418A - Tape for electronic device package - Google Patents

Abstract

The present invention provides an electronic device package tape which can suppress the occurrence of a void between an adhesive layer and an adherend by suppressing the occurrence of a pin mark due to deformation of the metal layer caused by the pushing up of a pin of a pickup device when picking up a metal layer to which an adhesive layer is attached from an adhesive tape. The electronic device package tape (1) of the present invention has an adhesive tape (5) having a substrate film (51) and an adhesive (52) layer, and a laminated body of an adhesive layer (4) and a metal layer (3) which are laminated and installed on the opposite side of the adhesive layer (52) to the substrate film (51), and the metal layer (3) is characterized in that the tensile strength is 350 MPa or more.

Description

Tape for electronic device packaging {TAPE FOR ELECTRONIC DEVICE PACKAGE}

The present invention relates to a tape for an electronic device package, and more particularly, to a tape for an electronic device package having a metal layer.

In recent years, electronic devices such as mobile phones and notebook PCs are being required to be further slimmed down and miniaturized. Therefore, in order to slim down and miniaturize electronic device packages such as semiconductor packages mounted on electronic devices, the number of electrodes on electronic devices or circuit boards is being increased, and the pitch is also being narrowed. Examples of such electronic device packages include flip chip (FC) mounting packages.

In flip-chip mounting packages, as described above, since the number of electrodes increases or the pitch is narrowed, an increase in the amount of heat generated is a problem. Therefore, as a heat dissipation structure of a flip-chip mounting package, it has been proposed to form a metal layer through an adhesive layer on the back surface of an electronic device (see, for example, Patent Document 1).

In addition, in flip chip mounting packages, there are cases where the coefficient of thermal expansion of the electronic device and the coefficient of thermal expansion of the circuit board are significantly different. In this case, during the manufacturing process of the electronic device package, when the intermediate product is heated and cooled, a difference in the amount of expansion and contraction occurs between the electronic device and the circuit board. This difference causes warping in the electronic device package. As a structure for suppressing such warping, forming a metal layer on the back surface of the electronic device via an adhesive layer has been proposed (for example, see Patent Document 2).

In addition, in a flip chip mounting package, it has also been proposed to install a metal layer through an adhesive layer on the back surface of an electronic device and use this metal layer as a protective layer for laser marking (see, for example, Patent Document 3).

In addition, in recent years, there have been cases where three-dimensional mounting is performed by additionally stacking another semiconductor chip of the same size on a semiconductor chip. Here, in order to stack another semiconductor chip of the same size on a semiconductor chip, it is necessary to stack a spacer between the two. This is because another semiconductor chip is also stacked on the electrode pad portion of the semiconductor chip. As the above-mentioned spacer, it has been proposed to use a metal layer with an adhesive layer attached (see, for example, Patent Document 4). Patent Document 4 describes a process in which a spacer is installed by a process of bonding a spacer adhesive sheet having a metal layer having an adhesive layer on at least one surface to a dicing sheet using the adhesive layer as a bonding surface, a process of dicing the spacer adhesive sheet to form a chip-shaped spacer having an adhesive layer, a process of pushing up the spacer with a pin, and peeling the pushed-up spacer together with the adhesive layer from the dicing sheet by a pickup device used when peeling a semiconductor chip from the dicing sheet together with the adhesive layer, and a process of fixing the spacer to an adherend via the adhesive layer.

Japanese Patent Publication No. 2007-235022 Japanese Patent No. 5487847 Japanese Patent No. 5419226 Japanese Patent No. 4954569

As described above, the metal layer having an adhesive layer attached thereto is useful for various electronic device packages, and it would be convenient if it could be picked up and fixed to an adherend using an existing device, as disclosed in Patent Document 4.

However, since metal is prone to plastic deformation resulting from metal bonding, there was a concern that when the pin was pushed up for pickup, the trace of the pin would remain. In addition, the adhesive layer laminated on the metal layer is flexible because it is in an uncured or semi-cured state. Therefore, when the trace of the pin occurs on the metal layer, the adhesive layer also follows suit. In this state, when the adhesive layer is bonded to the adherend, there was a problem that voids would occur, which could become a factor in package cracking.

Accordingly, the purpose of the present invention is to provide a tape for an electronic device package which can suppress the occurrence of voids between an adhesive layer and an adherend by suppressing deformation of the metal layer due to the pushing up of the pins of a pickup device when picking up a metal layer having an adhesive layer attached thereto from an adhesive tape and thereby suppressing the occurrence of traces of the pins.

In order to solve the above problems, a tape for an electronic device package according to the present invention comprises an adhesive tape having a base film and an adhesive layer, and a laminate of an adhesive layer and a metal layer laminated on the opposite side of the adhesive layer to the base film, wherein the metal layer is characterized by having a tensile strength of 350 MPa or more.

The tape for the above electronic device package preferably has the metal layer containing copper or aluminum.

It is preferable that the tape for the above electronic device package has a copper content of 99.95% or less in the metal layer.

In the tape for the above electronic device package, it is preferable that the metal layer is a copper alloy foil or an aluminum alloy foil.

The tape for the above electronic device package preferably includes an alloy in which the metal layer includes one or more kinds selected from the group consisting of copper, nickel, chromium, zirconium, zinc, tin, titanium, silicon, iron, manganese, magnesium, phosphorus, and cobalt.

In addition, it is preferable that the tape for the electronic device package includes an alloy including one or more of the metal layers selected from the group consisting of aluminum, nickel, chromium, zirconium, zinc, tin, magnesium, copper, manganese, titanium, silicon, iron, and cobalt.

Additionally, the tape for the electronic device package may have the metal layer include stainless steel.

In addition, it is preferable that the tape for the electronic device package has a thermal conductivity of the metal layer of 5 W/(m K) or more.

In addition, the tape for electronic device packaging preferably has an adhesive layer containing (A) an epoxy resin, (B) a curing agent, (C) an acrylic resin or phenoxy resin, and (D) a surface-treated inorganic filler.

In addition, it is preferable that the tape for electronic device packaging contains an acrylic polymer including an acrylic acid ester represented by CH ₂ = CHCOOR (wherein R is an alkyl group having 4 to 18 carbon atoms), a hydroxyl group-containing monomer, and an isocyanate compound having a radical reactive carbon-carbon double bond in the molecule, in which the adhesive layer is formed.

According to the present invention, when a metal layer to which an adhesive layer is attached is picked up from an adhesive tape, the metal layer is prevented from being deformed by the pushing up of the pin of the pickup device, thereby preventing voids from being generated between the adhesive layer and the adherend.

FIG. 1 is a cross-sectional view schematically illustrating the structure of a tape for an electronic device package according to an embodiment of the present invention.
Fig. 2 (a) is a plan view schematically illustrating the structure of a tape for an electronic device package according to an embodiment of the present invention, and (b) is a cross-sectional view thereof.
FIG. 3 is a perspective view schematically illustrating the structure of a tape for an electronic device package according to an embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating a method for manufacturing a tape for an electronic device package according to an embodiment of the present invention, wherein (A) is a longitudinal cross-sectional view illustrating a process for bonding a metal layer, (B) is a longitudinal cross-sectional view illustrating a process for bonding an adhesive layer, (C) is a short-side cross-sectional view illustrating a precut process, and (D) is a perspective view illustrating a process for removing an unnecessary portion.
FIG. 5 is an explanatory diagram schematically illustrating a method for manufacturing a tape for an electronic device package according to an embodiment of the present invention, wherein (A) is a short-side cross-sectional view illustrating a bonding process of an adhesive tape, (B) is a short-side cross-sectional view illustrating a precut process, and (C) is a short-side cross-sectional view illustrating a removal process of an unnecessary portion.
FIG. 6 is a cross-sectional view schematically illustrating a method of using a tape for an electronic device package according to an embodiment of the present invention.
FIG. 7 is a cross-sectional view schematically illustrating a method of using a tape for an electronic device package according to an embodiment of the present invention.
FIG. 8 is a cross-sectional view schematically illustrating the structure of an electronic device package using a tape for an electronic device package according to an embodiment of the present invention.

Below, embodiments of the present invention are described in detail.

Fig. 1 is a cross-sectional view showing a tape (1) for an electronic device package according to an embodiment of the present invention. The tape (1) for an electronic device package has an adhesive tape (5) including a base film (51) and an adhesive layer (52) provided on the base film (51), and a laminate of an adhesive layer (4) and a metal layer (3) is provided on the adhesive layer (52). In the present embodiment, an adhesive layer (4) and a metal layer (3) provided by laminating on the adhesive layer (4) are provided on the adhesive layer (52). The laminate of the adhesive layer (4) and the metal layer (3) includes an aspect in which they are indirectly laminated via a primer layer or the like to improve adhesion between the two.

As shown in FIGS. 2 and 3, the tape (1) for an electronic device package of the present invention preferably has an adhesive tape (5) cut into a shape corresponding to a ring frame (R) (see FIG. 7), and a metal layer (3) and an adhesive layer (4) also cut into a predetermined shape corresponding thereto (precut processing). In the present embodiment, precut processing is performed.

As shown in FIGS. 2 and 3, the tape (1) for electronic device packaging of the present invention is preferably in the form of a long base tape (2) wound in a roll shape in which a plurality of laminates are formed, each of which is a metal layer (3), an adhesive layer (4), and an adhesive tape (5) (label portion (5a)) cut into a shape corresponding to a ring frame (R), and the like. In the present embodiment, the tape is wound in a roll shape, but the laminates provided on the base tape (2) may be cut one by one.

When pre-cut and wound into a roll shape, as shown in FIGS. 2 and 3, the tape (1) for an electronic device package has a substrate tape (2), and on the substrate tape (2), a metal layer (3) having a predetermined flat shape, an adhesive layer (4) that is installed by laminating the metal layer (3) on the side opposite to the substrate tape (2) side of the metal layer (3) and has a predetermined flat shape, and an adhesive tape (5) that covers the adhesive layer (4) and has a label portion (5a) of a predetermined flat shape that is installed so as to contact the substrate tape (2) around the adhesive layer (4), and a peripheral portion (5b) that surrounds the outer side of the label portion (5a).

The label portion (5a) has a shape corresponding to the ring frame (R) for dicing. The shape corresponding to the shape of the ring frame (R) for dicing is preferably a similar shape that is approximately the same as the inner side of the ring frame (R) and larger than the size of the inner side of the ring frame (R). In addition, it does not necessarily have to be circular, but a shape close to circular is preferable, and a circular shape is more preferable. The peripheral portion (5b) includes a shape that completely surrounds the outer side of the label portion (5a) and a shape that does not completely surround it as illustrated. In addition, the peripheral portion (5b) does not have to be installed.

The adhesive layer (4) has a predetermined flat shape, and this flat shape is made smaller than the label portion (5a) so that a ring frame (R) can be attached to the periphery of the label portion (5a) of the adhesive tape (5) and pushed up by a pushing member of a pickup device (see (C) of Fig. 7). The adhesive layer (4) is preferably a similar shape that is approximately the same as the label portion (5a) and smaller than the size of the label portion (5a). The adhesive layer (4) does not necessarily have to be circular, but a shape close to circular is preferable, and a circular shape is more preferable.

The metal layer (3) has the same shape as the adhesive layer (4), and the adhesive layer (4) is laminated on the metal layer (3). The lamination referred to here is sufficient as long as the main part is laminated, and the metal layer (3) and the adhesive layer (4) do not necessarily have to have the same size, but from the perspective of manufacturing convenience, it is preferable that they have approximately the same shape. Hereinafter, each component will be described.

<Recording Tape (2)>

The substrate tape (2) may be composed of a known separator, but a substrate tape used in the precut processing of a tape for an electronic device package may also be used as is. When a substrate tape used in the precut processing of a tape for an electronic device package is used as is, since the substrate tape (2) needs to adhere and support the metal layer (3) during the precut processing, for example, a tape having a resin film and an adhesive layer for a substrate tape provided on one side of the resin film can be suitably used.

As the material of the resin film constituting the substrate tape (2), known materials can be used, and examples thereof include polyester (PET, PBT, PEN, PBN, PTT)-based, polyolefin (PP, PE)-based, copolymer (EVA, EEA, EBA)-based, and films in which some of these materials are substituted and further improved in adhesiveness or mechanical strength. Furthermore, a laminate of these films may be used. From the viewpoints of heat resistance, smoothness, and ease of acquisition, it is preferable to select from polyethylene terephthalate, polypropylene, and polyethylene.

The thickness of the resin film constituting the substrate tape (2) is not particularly limited and may be set appropriately, but is preferably 10 to 150 ㎛.

As the resin used in the adhesive layer for the substrate tape, known chlorinated polypropylene resins, acrylic resins, polyester resins, polyurethane resins, epoxy resins, etc. used in adhesives can be used, but an acrylic adhesive using an acrylic polymer as a base polymer is preferable.

As acrylic polymers, for example, (meth)acrylic acid alkyl esters (for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, eicosyl ester, etc., linear or branched alkyl esters having 1 to 30 carbon atoms in the alkyl group, particularly 4 to 18 carbon atoms) and Examples thereof include acrylic polymers using one or more types of (meth)acrylic acid cycloalkyl esters (e.g., cyclopentyl ester, cyclohexyl ester, etc.) as monomer components. In addition, (meth)acrylic acid ester refers to acrylic acid ester and/or methacrylic acid ester, and (meth) in the present invention has the same meaning.

Acrylic polymers may contain units corresponding to other monomer components copolymerizable with the (meth)acrylic acid alkyl ester or cycloalkyl ester, if necessary, for the purpose of modifying cohesion, heat resistance, etc. As such monomer components, for example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; Hydroxyl group-containing monomers such as (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 4-hydroxybutyl, (meth)acrylate 6-hydroxyhexyl, (meth)acrylate 8-hydroxyoctyl, (meth)acrylate 10-hydroxydecyl, (meth)acrylate 12-hydroxylauryl, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc.; Sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, etc. Monomers containing a phosphoric acid group such as 2-hydroxyethylacryloylphosphate; acrylamide, acrylonitrile, etc. These copolymerizable monomer components can be used alone or in combination of two or more. The amount of these copolymerizable monomers used is preferably 40 wt% or less of the total monomer components.

In addition, since the acrylic polymer is crosslinked, it can also include a polyfunctional monomer as a copolymerization monomer component as needed. As such polyfunctional monomers, for example, hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, etc. These polyfunctional monomers can also be used alone or in combination of two or more. The amount of polyfunctional monomer used is preferably 30 wt% or less of the total monomer components from the viewpoint of adhesive properties, etc.

The preparation of the acrylic polymer can be carried out by applying an appropriate method, such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or a suspension polymerization method, to a mixture of one or more types of monomer components, for example. The pressure-sensitive adhesive layer for the base tape is preferably composed of a composition that suppresses the content of low molecular weight substances, and from this point of view, it is preferable to use as a main component an acrylic polymer having a weight average molecular weight of 300,000 or more, particularly 400,000 to 3,000,000, so the adhesive can also be of an appropriate crosslinking type, such as an internal crosslinking method or an external crosslinking method.

In addition, in order to control the crosslinking density of the adhesive layer for the base tape and improve the peelability from the adhesive tape (5), an appropriate method such as a method of crosslinking using an appropriate external crosslinking agent such as a polyfunctional isocyanate compound, a polyfunctional epoxy compound, a melamine compound, a metal salt compound, a metal chelate compound, an amino resin compound, or a peroxide, or a method of mixing a low molecular weight compound having two or more carbon-carbon double bonds and crosslinking by irradiation with energy rays, etc. can be adopted. When an external crosslinking agent is used, the amount thereof used is appropriately determined depending on the balance with the base polymer to be crosslinked and further depending on the intended use as the adhesive. Generally, it is preferable to blend in an amount of about 20 parts by weight or less, further 0.1 to 20 parts by weight, with respect to 100 parts by weight of the base polymer.

The thickness of the adhesive layer for the substrate tape is not particularly limited and can be appropriately determined, but is generally about 5 to 200 ㎛. In addition, the adhesive layer for the substrate tape may be composed of a single layer or multiple layers.

<Adhesive Tape (5)>

As the adhesive tape (5), there is no particular limitation, and a conventional adhesive tape can be used. As the adhesive tape (5), for example, one in which an adhesive layer (52) is installed on a base film (51) can be suitably used.

As the base film (51), any known material can be used without particular limitation. However, when using a radiation-curable material as the adhesive layer (52) described later, it is preferable to use one that is radiation-transparent.

For example, as the material, homopolymers or copolymers of α-olefins such as polyethylene, polypropylene, ethylene-propylene copolymer, polybutene-1, poly-4-methylpentene-1, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomers, thermoplastic elastomers such as polyurethane, styrene-ethylene-butene or pentene copolymers, polyamide-polyol copolymers, and mixtures thereof can be enumerated. In addition, the base film may be a mixture of two or more materials selected from these groups, or may be a single-layer or multi-layered one.

The thickness of the substrate film (51) is not particularly limited and may be set appropriately, but is preferably 50 to 200 ㎛.

In order to improve the adhesion between the substrate film (51) and the adhesive layer (52), chemical or physical surface treatment such as chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, or ionizing radiation treatment may be performed on the surface of the substrate film (51).

In addition, in this embodiment, the adhesive layer (52) is directly installed on the substrate film (51), but it may be installed indirectly through a primer layer for increasing adhesion, an anchor layer for improving cutting properties during dicing, a stress relief layer, an antistatic layer, or the like.

The resin used in the adhesive layer (52) of the adhesive tape (5) is not particularly limited, and known chlorinated polypropylene resins, acrylic resins, polyester resins, polyurethane resins, epoxy resins, etc. used in adhesives can be used, but an acrylic adhesive using an acrylic polymer as a base polymer is preferable.

As acrylic polymers, for example, (meth)acrylic acid alkyl esters (for example, methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester, tridecyl ester, tetradecyl ester, hexadecyl ester, octadecyl ester, eicosyl ester, etc., linear or branched alkyl esters having 1 to 30 carbon atoms in the alkyl group, particularly 4 to 18 carbon atoms) and Examples thereof include acrylic polymers using one or more types of (meth)acrylic acid cycloalkyl esters (e.g., cyclopentyl ester, cyclohexyl ester, etc.) as monomer components. In addition, (meth)acrylic acid ester refers to acrylic acid ester and/or methacrylic acid ester, and (meth) in the present invention has the same meaning.

Acrylic polymers may contain units corresponding to other monomer components copolymerizable with the (meth)acrylic acid alkyl ester or cycloalkyl ester, if necessary, for the purpose of modifying cohesion, heat resistance, etc. As such monomer components, for example, carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride monomers such as maleic anhydride and itaconic anhydride; Hydroxyl group-containing monomers such as (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 4-hydroxybutyl, (meth)acrylate 6-hydroxyhexyl, (meth)acrylate 8-hydroxyoctyl, (meth)acrylate 10-hydroxydecyl, (meth)acrylate 12-hydroxylauryl, (4-hydroxymethylcyclohexyl)methyl (meth)acrylate, etc.; Sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, (meth)acryloyloxynaphthalenesulfonic acid, etc. Monomers containing a phosphoric acid group such as 2-hydroxyethylacryloylphosphate; acrylamide, acrylonitrile, etc. These copolymerizable monomer components can be used alone or in combination of two or more. The amount of these copolymerizable monomers used is preferably 40 wt% or less of the total monomer components.

In addition, since the acrylic polymer is crosslinked, it can also include a polyfunctional monomer as a copolymerization monomer component as needed. As such polyfunctional monomers, for example, hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, etc. These polyfunctional monomers can also be used alone or in combination of two or more. The amount of polyfunctional monomer used is preferably 30 wt% or less of the total monomer components from the viewpoint of adhesive properties, etc.

The preparation of the acrylic polymer can be carried out by applying an appropriate method, such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, or a suspension polymerization method, to a mixture of one or more types of monomer components, for example. The adhesive layer is preferably composed of a composition that suppresses the content of low molecular weight substances in terms of preventing contamination of the wafer, and from this point of view, it is preferable to use as a main component an acrylic polymer having a weight average molecular weight of 300,000 or more, particularly 400,000 to 3,000,000, so the adhesive can also be of an appropriate crosslinking type, such as an internal crosslinking method or an external crosslinking method.

In addition, in order to control the crosslinking density of the adhesive layer (52) to improve the pick-up property, for example, a method of crosslinking using an appropriate external crosslinking agent such as a polyfunctional isocyanate compound, a polyfunctional epoxy compound, a melamine compound, a metal salt compound, a metal chelate compound, an amino resin compound, or a peroxide, or a method of crosslinking by mixing a low-molecular-weight compound having two or more carbon-carbon double bonds and irradiating the mixture with energy rays, etc., can be adopted. When an external crosslinking agent is used, the amount thereof used is appropriately determined depending on the balance with the base polymer to be crosslinked, and further depending on the intended use as the adhesive. Generally, it is preferable to blend in an amount of about 20 parts by weight or less, more preferably 0.1 to 20 parts by weight, with respect to 100 parts by weight of the base polymer. In addition, in the adhesive, from the viewpoint of preventing deterioration, etc., various additives such as tackifiers and anti-aging agents may be used in addition to the above components, as necessary.

As the adhesive constituting the adhesive layer (52), a radiation-curable adhesive is preferable. As the radiation-curable adhesive, an example of an additive-type radiation-curable adhesive in which a radiation-curable monomer component or a radiation-curable oligomer component is mixed with the above-mentioned adhesive can be exemplified.

Examples of the radiation-curable monomer component to be mixed include urethane (meth)acrylate, 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, etc. These monomer components can be used alone or in combination of two or more.

In addition, the radiation-curable oligomer component can include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based, and the molecular weight thereof is suitably in the range of about 100 to 30,000. The blending amount of the radiation-curable monomer component or oligomer component can be appropriately determined in an amount capable of reducing the adhesive strength of the adhesive layer depending on the type of the adhesive layer. Generally, it is, for example, about 5 to 500 parts by weight, and preferably about 70 to 150 parts by weight, relative to 100 parts by weight of the base polymer such as the acrylic polymer constituting the adhesive.

In addition, as the radiation-curable adhesive, in addition to the above-mentioned additive-type radiation-curable adhesive, there may also be mentioned an inherent-type radiation-curable adhesive using a base polymer having a carbon-carbon double bond in the polymer side chain or main chain or at the main chain terminal. The inherent-type radiation-curable adhesive is preferable because it does not need to contain, or does not contain, a low-molecular-weight component such as an oligomer component, or does not contain much of it, so that the oligomer component does not move in the adhesive over time, and an adhesive layer having a stable layer structure can be formed.

The base polymer having a carbon-carbon double bond can be used without particular limitation as long as it has a carbon-carbon double bond and also has adhesiveness. As such a base polymer, an acrylic polymer is preferable as the basic skeleton. As the basic skeleton of the acrylic polymer, the acrylic polymers exemplified above can be mentioned.

The method for introducing a carbon-carbon double bond into an acrylic polymer is not particularly limited, and various methods can be employed, but it is easy to introduce a carbon-carbon double bond into a polymer side chain in terms of molecular design. For example, a method may be exemplified in which a monomer having a functional group is copolymerized with an acrylic polymer in advance, and then a compound having a functional group capable of reacting with the functional group and a carbon-carbon double bond is condensed or added while maintaining the radiation curability of the carbon-carbon double bond.

Examples of combinations of these functional groups include a carboxylic acid group and an epoxy group, a carboxylic acid group and an aziridyl group, a hydroxyl group and an isocyanate group, etc. Among these combinations of functional groups, a combination of a hydroxyl group and an isocyanate group is preferable because of the ease of tracking the reaction. In addition, as long as the combination of these functional groups produces an acrylic polymer having the carbon-carbon double bond, the functional group may be on either side of the acrylic polymer and the compound, but in the preferable combination described above, it is preferable that the acrylic polymer has a hydroxyl group and the compound has an isocyanate group. In this case, examples of the isocyanate compound having a carbon-carbon double bond include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, and the like. In addition, as acrylic polymers, copolymers of the hydroxyl group-containing monomers exemplified above or ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether are used.

The inherent radiation-curable pressure-sensitive adhesive can use the base polymer having the carbon-carbon double bond (particularly an acrylic polymer) alone, but can also blend a photopolymerizable compound such as the radiation-curable monomer component or oligomer component so long as the properties are not deteriorated. The blending amount of the photopolymerizable compound is usually within a range of 30 parts by weight or less, and preferably within a range of 0 to 10 parts by weight, relative to 100 parts by weight of the base polymer.

In the case of radiation-curable adhesives, it is preferable to contain a photopolymerization initiator when curing by ultraviolet rays or the like.

Among the acrylic polymers described above, acrylic polymer A is particularly preferable, which comprises an acrylic acid ester represented by CH ₂ = CHCOOR (wherein R is an alkyl group having 4 to 18 carbon atoms), a hydroxyl group-containing monomer, and an isocyanate compound having a radically reactive carbon-carbon double bond in the molecule.

If the number of carbon atoms in the alkyl group of the acrylic acid alkyl ester is less than 4, the polarity is high and the peeling force becomes too high, which may result in reduced pick-up properties. On the other hand, if the number of carbon atoms in the alkyl group of the acrylic acid alkyl ester exceeds 18, the glass transition temperature of the adhesive layer (52) becomes too high, which may result in reduced adhesive properties at room temperature, and as a result, peeling of the metal layer (3) may occur during dicing or expanding.

The above acrylic polymer A may, if necessary, contain units corresponding to other monomer components.

In the acrylic polymer A, an isocyanate compound having a radically reactive carbon-carbon double bond is used. That is, the acrylic polymer preferably has a configuration in which a double bond-containing isocyanate compound is added to a polymer by a monomer composition such as the acrylic acid ester or a hydroxyl group-containing monomer. Therefore, the acrylic polymer preferably has a radically reactive carbon-carbon double bond in its molecular structure. Thereby, an active energy ray-curable pressure-sensitive adhesive layer (such as an ultraviolet ray-curable pressure-sensitive adhesive layer) that is cured by irradiation with an active energy ray (such as ultraviolet ray) can be formed, and the peeling strength between the metal layer (3) and the pressure-sensitive adhesive layer can be reduced.

Examples of the double bond-containing isocyanate compounds include methacryloyl isocyanate, acryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, 2-acryloyloxyethyl isocyanate, m-isopropenyl-α,α-dimethylbenzyl isocyanate, and the like. The double bond-containing isocyanate compounds can be used alone or in combination of two or more.

In addition, in the active energy ray-curable pressure-sensitive adhesive, an external cross-linking agent may be appropriately used in order to adjust the adhesiveness before or after active energy ray irradiation. As a specific means of the external cross-linking method, a method of adding a so-called cross-linking agent such as a polyisocyanate compound, an epoxy compound, an aziridine compound, or a melamine-based cross-linking agent and causing a reaction can be exemplified. When an external cross-linking agent is used, the amount thereof is appropriately determined according to the balance with the base polymer to be cross-linked and, further, according to the intended use as the adhesive. The amount of the external cross-linking agent to be used is generally 20 parts by weight or less (preferably 0.1 to 10 parts by weight) with respect to 100 parts by weight of the base polymer. In addition, in the active energy ray-curable pressure-sensitive adhesive, in addition to the above components, various additives such as conventionally known tackifiers, anti-aging agents, and foaming agents may be blended as necessary.

The thickness of the adhesive layer (52) is not particularly limited and can be appropriately determined, but is generally about 5 to 200 ㎛. In addition, the adhesive layer (52) may be composed of a single layer or multiple layers.

<Metal layer (3)>

The metal constituting the metal layer (3) is not particularly limited as long as the tensile strength of the metal layer (3) is 350 MPa or more, and for example, it is preferable to include at least one selected from the group consisting of stainless steel, aluminum, iron, titanium, tin, nickel, and copper from the viewpoints of heat dissipation and warpage prevention of the electronic device package (8). Among these, it is particularly preferable to include copper from the viewpoint that it has high thermal conductivity and that a heat dissipation effect is obtained. Furthermore, from the viewpoint of warpage prevention of the electronic device package (8), it is particularly preferable to include aluminum.

It is preferable that the metal layer (3) includes an alloy including one or more kinds selected from the group consisting of copper, nickel, chromium, zirconium, zinc, tin, titanium, silicon, iron, manganese, magnesium, phosphorus, and cobalt. When the metal layer (3) includes a copper alloy, the copper content is preferably 99.95% or less. In addition, the metal layer (3) may be an alloy including aluminum, and one or more kinds selected from the group consisting of nickel, chromium, zirconium, zinc, tin, magnesium, copper, manganese, titanium, silicon, iron, and cobalt. Furthermore, it is also preferable that the metal layer (3) includes stainless steel. Stainless steel contains iron as a main component and chromium. Stainless steel has an iron content of 50% or more, and a chromium content of 10.5% or more, more preferably 11% or more. By configuring the metal layer (3) with such a copper alloy, aluminum alloy, or stainless steel, the tensile strength can be increased.

When the tensile strength of the metal layer (3) is 350 MPa or more, when the metal layer to which the adhesive layer is attached is picked up from the adhesive tape, the metal layer can be prevented from being deformed by the pin of the pickup device being pushed up, thereby generating a trace of the pin. The tensile strength of the metal layer (3) has no particular upper limit, but from the viewpoint of thin film processability, it is preferably 1000 MPa or less. The tensile strength of the metal layer (3) is a value measured at 25°C in accordance with JIS Z 2241.

It is preferable that the metal layer (3) has a thermal conductivity of 5 W/(m K) or more. If the thermal conductivity is 5 W/(m K) or more, the heat dissipation is superior to that of the sealant. If it is 85 W/(m K) or more, the heat dissipation is superior to that of the wafer, which is more preferable.

The thickness of the metal layer (3) is 5 ㎛ or more and less than 200 ㎛. By setting it to 5 ㎛ or more, it is possible to suppress the occurrence of pin marks due to deformation of the metal layer caused by the pins of the pickup device being pushed up. In addition, if it is less than 200 ㎛, winding processing is easy.

As this metal layer (3), a metal foil can be used.

<Adhesive layer (4)>

The adhesive layer (4) is a film-formed adhesive in advance.

The adhesive layer (4) is formed of at least a thermosetting resin, and is preferably formed of at least a thermosetting resin and a thermoplastic resin.

Examples of the thermoplastic resin include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, polybutadiene resin, polycarbonate resin, thermoplastic polyimide resin, polyamide resin such as 6-nylon or 6,6-nylon, phenoxy resin, acrylic resin, saturated polyester resin such as PET (polyethylene terephthalate) or PBT (polybutylene terephthalate), polyamideimide resin, or fluororesin. The thermoplastic resin can be used alone or in combination of two or more. Among these thermoplastic resins, acrylic resin is particularly preferable because it has less ionic impurities and excellent stress relaxation properties, and phenoxy resin is particularly preferable because it has both flexibility and strength and high toughness, and thus it is easy to secure the reliability of semiconductor devices from each of these viewpoints.

As the acrylic resin, there is no particular limitation, and examples thereof include polymers containing as components one or more esters of acrylic acid or methacrylic acid having a straight-chain or branched alkyl group having 30 or fewer carbon atoms (preferably 1 to 18 carbon atoms). That is, in the present invention, the acrylic resin has a broad meaning that also includes methacrylic resin. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an isobutyl group, a pentyl group, an isopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, an isooctyl group, a nonyl group, an isononyl group, a decyl group, an isodecyl group, an undecyl group, a dodecyl group (lauryl group), a tridecyl group, a tetradecyl group, a stearyl group, an octadecyl group, and the like.

In addition, other monomers for forming the acrylic resin (monomers other than alkyl esters of acrylic acid or methacrylic acid having 30 or fewer carbon atoms in the alkyl group) are not particularly limited, and examples thereof include carboxyl group-containing monomers such as acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentylacrylate, itaconic acid, maleic acid, fumaric acid, or crotonic acid, acid anhydride monomers such as maleic anhydride or itaconic anhydride, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 4-hydroxybutyl, (meth)acrylic acid 6-hydroxyhexyl, (meth)acrylic acid 8-hydroxyoctyl, (meth)acrylic acid 10-hydroxydecyl, (meth)acrylic acid 12-hydroxylauryl, or Examples thereof include hydroxyl group-containing monomers such as (4-hydroxymethylcyclohexyl)-methyl acrylate, sulfonic acid group-containing monomers such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl(meth)acrylate or (meth)acryloyloxynaphthalenesulfonic acid, or phosphoric acid group-containing monomers such as 2-hydroxyethylacryloylphosphate. In addition, (meth)acrylic acid refers to acrylic acid and/or methacrylic acid, and (meth) in the present invention has the same meaning.

In addition, as thermosetting resins, in addition to epoxy resins and phenol resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, thermosetting polyimide resins, etc. can be mentioned. Thermosetting resins can be used alone or in combination of two or more. As thermosetting resins, epoxy resins that contain little ionic impurities that corrode semiconductor elements are particularly preferable. In addition, phenol resins can be suitably used as curing agents for epoxy resins.

As the epoxy resin, there is no particular limitation, and for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, brominated bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol AF type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, tetraphenylolethane type epoxy resin, or other bifunctional epoxy resins or polyfunctional epoxy resins, or epoxy resins such as hydantoin type epoxy resin, trisglycidyl isocyanurate type epoxy resin, or glycidylamine type epoxy resin can be used.

As epoxy resins, novolac-type epoxy resins, biphenyl-type epoxy resins, trishydroxyphenylmethane-type epoxy resins, and tetraphenylolethane-type epoxy resins are particularly preferable. This is because these epoxy resins have high reactivity with phenol resins as hardeners and excellent heat resistance, etc.

In addition, phenol resins act as curing agents for epoxy resins, and examples thereof include novolac-type phenol resins such as phenol novolac resins, phenol aralkyl resins, cresol novolac resins, tert-butylphenol novolac resins, and nonylphenol novolac resins; resol-type phenol resins; and polyoxystyrenes such as polyparaoxystyrene. Phenol resins can be used alone or in combination of two or more. Among these phenol resins, phenol novolac resins and phenol aralkyl resins are particularly preferable. This is because they can improve the connection reliability of semiconductor devices.

The mixing ratio of the epoxy resin and the phenol resin is preferably such that, for example, per 1 equivalent of the epoxy group in the epoxy resin component, the hydroxyl group in the phenol resin amounts to 0.5 to 2.0 equivalents. More preferably, it is 0.8 to 1.2 equivalents. That is, if the mixing ratio of the two is outside the above range, the curing reaction does not proceed sufficiently, and the properties of the cured epoxy resin are likely to deteriorate.

In addition, a heat curing accelerator for epoxy resin and phenol resin may be used. The heat curing accelerator is not particularly limited, and an appropriate one may be selected and used from known heat curing accelerators. The heat curing accelerator may be used alone or in combination of two or more. As the heat curing accelerator, for example, an amine-based curing accelerator, a phosphorus-based curing accelerator, an imidazole-based curing accelerator, a boron-based curing accelerator, a phosphorus-boron-based curing accelerator, etc. may be used.

As a hardener for the epoxy resin, it is preferable to use a phenol resin as described above, but known hardeners such as imidazoles, amines, and acid anhydrides may also be used.

It is important that the adhesive layer (4) has adhesiveness (adhesion) to the adherend (9) such as an electronic device. Therefore, in order to crosslink the adhesive layer (4) to some extent in advance, a multifunctional compound that reacts with a functional group at the end of the molecular chain of the polymer may be added as a crosslinking agent. As a result, the adhesive properties under high temperatures can be improved, and the heat resistance can be improved.

As the crosslinking agent, there is no particular limitation, and known crosslinking agents can be used. Specifically, for example, in addition to isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, and peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, and amine-based crosslinking agents can be mentioned. As the crosslinking agent, an isocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferable. In addition, the crosslinking agents can be used alone or in combination of two or more.

In addition, in the present invention, instead of using a crosslinking agent, or together with using a crosslinking agent, it is also possible to perform crosslinking treatment by irradiation with electron beams or ultraviolet rays.

In the adhesive layer (4), other additives can be appropriately mixed as needed. As other additives, for example, in addition to fillers, flame retardants, silane coupling agents, and ion trapping agents, extenders, anti-aging agents, antioxidants, and surfactants can be mentioned.

As the filler, either an inorganic filler or an organic filler may be used, but an inorganic filler is preferred. By mixing a filler such as an inorganic filler, it is possible to improve the thermal conductivity of the adhesive layer (4), adjust the elastic modulus, etc. As the inorganic filler, examples thereof include ceramics such as silica, clay, gypsum, calcium carbonate, barium sulfate, alumina, beryllium oxide, silicon carbide, aluminum nitride, and silicon nitride; metals such as aluminum, copper, silver, gold, nickel, chromium, lead, tin, zinc, palladium, and solder; alloys; and various inorganic powders containing carbon and the like. The filler can be used alone or in combination of two or more. Among them, silica or alumina is preferred, and as the silica, fused silica is particularly preferred. In addition, the average particle diameter of the inorganic filler is preferably within a range of 0.001 μm to 80 μm. The average particle size of the inorganic filler can be measured, for example, by a laser diffraction type particle size distribution measuring device.

The blending amount of the filler (especially the inorganic filler) is preferably 98 wt% or less (0 wt% to 98 wt%) with respect to the organic resin component, and particularly in the case of silica, it is preferably 0 wt% to 70 wt%, and in the case of a functional inorganic filler such as a heat-conducting or electrically conductive filler, it is preferably 10 wt% to 98 wt%.

In addition, flame retardants include, for example, antimony trioxide, antimony pentoxide, and brominated epoxy resins. Flame retardants can be used alone or in combination of two or more. Silane coupling agents include, for example, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropylmethyldiethoxysilane. Silane coupling agents can be used alone or in combination of two or more. Ion trap agents include, for example, hydrotalcites and bismuth hydroxide. Ion trap agents can be used alone or in combination of two or more.

From the viewpoints of adhesion and reliability, it is particularly preferable that the adhesive layer (4) contain (A) epoxy resin, (B) hardener, (C) acrylic resin or phenoxy resin, and (D) surface-treated inorganic filler.

(A) By using an epoxy resin, high adhesiveness, water resistance, and heat resistance can be obtained. As the epoxy resin, the known epoxy resin described above can be used. (B) As the curing agent, the known curing agent described above can be used.

(C) Acrylic resin has both flexibility and strength and high toughness. A preferable acrylic resin is a (meth)acrylic copolymer containing a crosslinkable functional group obtained by polymerizing a monomer having a Tg (glass transition temperature) of -50°C to 50°C and an epoxy group, a glycidyl group, an alcoholic hydroxyl group, a phenolic hydroxyl group or a carboxyl group as a crosslinkable functional group. In addition, if it contains acrylonitrile or the like to exhibit rubber characteristics, higher toughness is obtained.

In addition, phenoxy resin has a long molecular chain and is similar in structure to epoxy resin, and acts as a flexible material in a composition with a high crosslinking density, and provides high toughness, so a composition with high strength and toughness is obtained. Preferred phenoxy resins are those having a bisphenol A type main skeleton, but other commercially available phenoxy resins such as bisphenol F type phenoxy resin, bisphenol A/F mixed type phenoxy resin, and brominated phenoxy resin can be mentioned as preferable ones.

(D) As the surface-treated inorganic filler, an inorganic filler surface-treated with a coupling agent can be exemplified. As the inorganic filler, the known inorganic filler described above can be used, preferably silica or alumina. By being surface-treated with a coupling agent, the dispersibility of the inorganic filler becomes good. Therefore, since the fluidity is excellent, the adhesion with the metal layer (3) can be improved. In addition, since the inorganic filler can be highly filled, the moisture resistance can be improved by lowering the absorption rate.

For example, surface treatment of an inorganic filler by a silane coupling agent is carried out by a known method by dispersing the inorganic filler in a silane coupling agent solution, thereby causing a hydroxyl group present on the surface of the inorganic filler and a hydrolyzed silanol group such as an alkoxy group of the silane coupling agent to react to form a Si-O-Si bond on the surface of the inorganic filler.

The thickness of the adhesive layer (4) is not particularly limited, but from the viewpoint of normal handling, it is preferably 3 µm or more, more preferably 5 µm or more, and in order to contribute to thinning of the semiconductor package, it is preferably 150 µm or less, more preferably 100 µm or less. The adhesive layer (4) may be composed of a single layer or may be composed of multiple layers.

In addition, it is preferable that the adhesive layer (4) has a peeling force (23°C, peeling angle 180°, linear speed 300 mm/min) of 0.3 N or more with respect to the metal layer (3) in the B stage (uncured or semi-cured state). If the peeling force is less than 0.3 N, there is a risk that peeling may occur between the adhesive layer (4) and the metal layer (3) during dicing.

The absorption rate of the adhesive layer (4) is preferably 1.5 vol% or less. The method for measuring the absorption rate is as follows. That is, an adhesive layer (4) (film-shaped adhesive) having a size of 50 × 50 mm is used as a sample, the sample is dried in a vacuum dryer at 120° C. for 3 hours, cooled in a desiccator, and the dry mass is measured to obtain M1. The sample is immersed in distilled water at room temperature for 24 hours, then taken out, the sample surface is wiped with a filter paper, and quickly weighed to obtain M2. The absorption rate is calculated by the following equation (1).

Here, d is the density of the film.

If the absorption rate exceeds 1.5 vol%, there is a risk that package cracks may occur during solder reflow due to the absorbed moisture.

The saturated moisture absorption rate of the adhesive layer (4) is preferably 1.0 vol% or less. The method for measuring the saturated moisture absorption rate is as follows. That is, a circular adhesive layer (4) (film-shaped adhesive) having a diameter of 100 mm is used as a sample, the sample is dried in a vacuum dryer at 120°C for 3 hours, cooled in a desiccator, and the dry mass is measured to obtain M1. The sample is taken out after absorbing moisture in a constant temperature and humidity chamber at 85°C and 85% RH for 168 hours, and quickly weighed to obtain M2. The saturated moisture absorption rate is calculated by the following equation (2).

Here, d is the density of the film.

If the saturated moisture absorption rate exceeds 1.0 vol%, there is a risk that the vapor pressure value will increase due to moisture absorption during reflow, making it difficult to obtain good reflow characteristics.

The residual volatile content of the adhesive layer (4) is preferably 3.0 wt% or less. The method for measuring the residual volatile content is as follows. That is, an adhesive layer (4) (film-shaped adhesive) having a size of 50 × 50 mm is used as a sample, the initial mass of the sample is measured and designated as M1, and the sample is heated in a hot air circulation thermostatic chamber at 200°C for 2 hours and then weighed and designated as M2. The residual volatile content is calculated by the following equation (3).

If the residual volatile content exceeds 3.0 wt%, there is a risk that the solvent will volatilize due to heating during packaging, causing voids to form inside the adhesive layer (4), resulting in package cracks.

It is preferable that the ratio of the coefficient of linear expansion of the metal layer (3) to the coefficient of linear expansion of the adhesive layer (4) (coefficient of linear expansion of the metal layer (3)/coefficient of linear expansion of the adhesive layer (4)) be 0.2 or more. If the ratio is less than 0.2, peeling is likely to occur between the metal layer (3) and the adhesive layer (4), and there is a risk that package cracks may occur during packaging, thereby lowering reliability.

Next, a method for manufacturing a tape (1) for an electronic device package according to the present embodiment will be described. First, a long metal layer (3) is prepared. As the metal layer (3), a commercially available metal foil may be used. Next, as shown in Fig. 4 (A), the metal layer (3) is bonded to the adhesive surface of a long base tape (2) using a bonding roller (r) or the like.

Separately, a long film-shaped adhesive layer (4) is formed. The adhesive layer (4) can be formed using a conventional method of preparing a resin composition and forming it in a film-shaped layer. Specifically, for example, a method may be exemplified in which the resin composition is applied on a suitable separator (release paper, etc.) and dried (in cases where heat curing is required, heat treatment is performed as necessary and then dried), thereby forming the adhesive layer (4). The resin composition may be a solution or a dispersion.

Next, as shown in (B) of Fig. 4, an adhesive layer (4) peeled off from a separator is bonded to a metal layer (3) bonded to a substrate tape (2) using a bonding roller (r) or the like.

In addition, in the above description, after bonding the metal layer (3) to the substrate tape (2), the adhesive layer (4) is bonded on the metal layer (3), but after bonding the metal layer (3) and the adhesive layer (4), the surface on the metal layer (3) side may be bonded to the substrate tape (2).

Next, as shown in (C) of Fig. 4, the adhesive layer (4) and the metal layer (3) are pre-cut into a predetermined shape (here, a circular shape) using a pressure cutting blade or the like, and as shown in (D) of Fig. 4, the unnecessary portion (6) around them is peeled off from the substrate tape (2) and removed. At this time, the adhesive layer (4) and the metal layer (3) may be cut into pieces in advance into a predetermined size, such as a size corresponding to a semiconductor chip (C), using a pressure cutting saw having a grid-like shape and a circular outer edge.

In addition, the method for forming a metal layer (3) and an adhesive layer (4) of a predetermined shape on a substrate tape (2) is not limited to the above, and a long metal layer (3) may be bonded to a long substrate tape (2), punched into a predetermined shape, and after removing an unnecessary portion (6), an adhesive layer (4) formed into a predetermined shape may be bonded onto the metal layer (3) of the predetermined shape, or a metal layer (3) and an adhesive layer (4) formed in a predetermined shape in advance may be bonded to the substrate tape (2). However, from the viewpoint of simplicity of the manufacturing process, it is preferable to manufacture by the processes illustrated in (A) to (D) of the above-described Figs.

In addition, an adhesive tape (5) is produced separately. The base film can be formed into a film by a conventionally known film forming method. As the film forming method, for example, a calendar film forming method, a casting method in an organic solvent, an inflation extrusion method in a closed system, a T-die extrusion method, a coextrusion method, a dry lamination method, etc. can be exemplified. Next, an adhesive composition is applied onto the base film and dried (or crosslinked by heating if necessary) to form an adhesive layer. Examples of the application method include roll application, screen application, and gravure application. In addition, the adhesive composition may be applied directly to the base film to form an adhesive layer on the base film, or the adhesive composition may be applied to a release paper or the like having its surface peeled off to form an adhesive layer, and then the adhesive layer may be transferred to the base film. Thereby, an adhesive tape (5) in which an adhesive layer is formed on the base film is produced.

Thereafter, as shown in (A) of Fig. 5, the adhesive tape (5) is laminated so that the surface on the adhesive layer (52) side of the adhesive tape (5) is in contact with the surface on the adhesive layer (4) side of the metal layer (3) and the adhesive layer (4) of a predetermined shape installed on the substrate tape (2).

Next, as shown in (B) of Fig. 5, the adhesive tape (5) is pre-cut into a predetermined shape using a pressurized cutting blade or the like, and as shown in (C) of Fig. 5, unnecessary portions (7) around the edges are peeled off from the substrate tape (2) to thereby produce a tape (1) for an electronic device package. In addition, the substrate tape (2) used in the pre-cut process may be peeled off, and a known separator may be bonded to the adhesive layer (52) of the adhesive tape (5).

<How to use>

Next, a method for manufacturing an electronic device package (8) using the tape (1) for an electronic device package of the present embodiment will be described with reference to FIGS. 6 to 8. In addition, in the present embodiment, a semiconductor chip (C) flip-chip-connected on an adherend (9) is described as an example of an electronic device package (8).

[Semiconductor wafer (W) mounting process]

First, a separate dicing tape (D) identical to the adhesive tape (5) of the electronic device package tape (1) of the present invention is prepared, and a semiconductor wafer (W) is adhered to the central portion of the dicing tape (D) as shown in Fig. 6 (A), and this is fixed by adhesive holding (mounting process of the semiconductor wafer (W)), and a ring frame (R) is bonded to the periphery of the dicing tape (D). At this time, the dicing tape (D) is adhered to the back surface of the semiconductor wafer (W). The back surface of the semiconductor wafer (W) means the surface opposite to the circuit surface (also called a non-circuit surface, a non-electrode formation surface, etc.). The bonding method is not particularly limited, but a method by heat compression is preferable. The compression is usually performed while pressing by a pressing means such as a pressing roll.

[Dicing process of semiconductor wafer (W)]

Next, as shown in (B) of Fig. 6, dicing of the semiconductor wafer (W) is performed. Thereby, the semiconductor wafer (W) is cut into a predetermined size and divided into pieces (small pieces), thereby manufacturing a semiconductor chip (C). Dicing is performed, for example, on the circuit surface side of the semiconductor wafer (W) according to a conventional method. In addition, in this process, a cutting method called a full cut, which performs cutting up to the adhesive tape (5), can be adopted, for example. The dicing device used in this process is not particularly limited, and a conventionally known device can be used. In addition, when expanding the dicing tape (D), the expanding can be performed using a conventionally known expanding device.

[Pickup process of semiconductor chip (C)]

As illustrated in (C) of Fig. 6, a semiconductor chip (C) is picked up and the semiconductor chip (C) is peeled off from the dicing tape (D). The method of picking up is not particularly limited, and various conventionally known methods can be adopted. For example, a dicing tape (D) in which a semiconductor chip (C) and a ring frame (R) are joined is loaded on a stage (S) of a pickup device with the substrate film side facing down, and while the ring frame (R) is fixed, a hollow cylindrical pushing member (T) is raised to expand the dicing tape (D). In this state, an individual semiconductor chip (C) is pushed up from the substrate film side of the dicing tape (D) by a pin (N), and the pushed-up semiconductor chip (C) is picked up by a pickup device, etc.

[Flip chip connection process]

The picked-up semiconductor chip (C) is fixed to an adherend (9), such as a substrate, by a flip chip bonding method (flip chip mounting method), as illustrated in (D) of Fig. 6. Specifically, the semiconductor chip (C) is fixed to an adherend (9) in a manner in which the circuit surface (also referred to as a surface, a circuit pattern formation surface, an electrode formation surface, etc.) of the semiconductor chip (C) faces the adherend (9) according to a conventional method. For example, first, flux is attached to a bump (10) as a connecting portion formed on the circuit surface side of the semiconductor chip (C). Next, by bringing the bump (10) of the semiconductor chip (C) into contact with the conductive material (11) (solder, etc.) for bonding attached to the connection pad of the adherend (9) and pressing it while melting the bump (10) and the conductive material (11), electrical conductivity between the semiconductor chip (C) and the adherend (9) is secured, and the semiconductor chip (C) can be fixed to the adherend (9) (flip chip bonding process). At this time, a gap is formed between the semiconductor chip (C) and the adherend (9), and the distance between the gaps is generally about 30 µm to 300 µm. The flux remaining on the opposing surfaces or gaps between the semiconductor chip (C) and the adherend (9) is cleaned and removed.

As the adherend (9), various substrates such as a lead frame or a circuit board (such as a wiring circuit board) can be used. The material of such a substrate is not particularly limited, but may include a ceramic substrate or a plastic substrate. Examples of the plastic substrate include an epoxy substrate, a bismaleimidetriazine substrate, a polyimide substrate, and the like. In addition, by using another semiconductor chip as the adherend (9) and flip-chip-connecting the semiconductor chip (C), a chip-on-chip structure can be achieved.

Next, as shown in (A) of Fig. 7, the substrate tape (2) of the tape (1) for an electronic device package according to the present embodiment is peeled off, exposing the metal layer (3) and the adhesive layer (52) of the adhesive tape (5), and fixing the peripheral part of the adhesive layer (52) to the ring frame (R).

Next, as shown in (B) of Fig. 7, the metal layer (3) and the adhesive layer (4) are cut into pieces corresponding to a size of the semiconductor chip (C). The cutting can be performed in the same process as the dicing process of the semiconductor wafer (W) described above. In addition, if the metal layer (3) and the adhesive layer (4) are pre-cut into pieces, this process is not performed.

Next, as shown in (C) of Fig. 7, the fragmented metal layer (3) and adhesive layer (4) are picked up and peeled off from the adhesive tape (5). Picking up can be performed in the same process as the pickup process of the semiconductor chip (C) described above.

Next, the adhesive layer (4) side of the picked-up metal layer (3) and adhesive layer (4) is bonded to the back surface of the flip-chip-connected semiconductor chip (C), as shown in Fig. 8. Thereafter, a sealant (sealing resin, etc.) is filled into the periphery of the semiconductor chip (C) with the metal layer (3) attached and the gap between the semiconductor chip (C) and the adherend (9) to seal it. The sealing is performed according to a conventional method. At this time, since the metal layer (3) is provided on the back surface of the semiconductor chip (C), warpage caused by the difference in thermal expansion rates between the semiconductor chip (C) and the adherend (9) in the flip-chip bonding process is offset by the difference in thermal expansion rates between the semiconductor chip (C) and the metal layer (3). In addition, since the metal layer (3) is provided on the back surface of the semiconductor chip (C), heat generation during use as an electronic device is dissipated by the metal layer (3).

In addition, in the above description, a package structure in which a metal layer (3) is directly installed on the back surface of a semiconductor chip (C) through an adhesive layer (4) and the metal layer (3) is also sealed together with the semiconductor chip (C) has been described, but after sealing the semiconductor chip (C), the metal layer (3) may be installed on the upper surface of a sealing body through an adhesive layer (4). Since the electronic device package (8) causes warpage even during sealing, by installing the metal layer (3) on the upper surface of the sealing body, the warpage during sealing can be offset.

In addition, in the above description, the semiconductor chip (C) flip-chip-connected on the adherend (9) as the electronic device package (8) was described as an example, but it is not limited to this, and for example, in an electronic device package structure in which another semiconductor chip of the same size is laminated on a semiconductor chip, in order to use the metal layer (3) of the tape (1) for an electronic device package of the present invention as a spacer between the two chips, the metal layer (3) may be installed on the lower semiconductor chip through the adhesive layer (4).

In addition, in this embodiment, the adhesive layer (52), the adhesive layer (4), and the metal layer (3) are installed in this order, but the adhesive layer (52), the metal layer (3), and the adhesive layer (4) may be installed in this order. In this case, the semiconductor wafer may be bonded on the adhesive layer (4), the semiconductor wafer, the metal layer (3), and the adhesive layer (4) may be diced, and they may be picked up together. However, as described above, the semiconductor wafer, the metal layer (3), and the adhesive layer (4) may be diced separately and picked up, and after the semiconductor chip is flip-chip connected, the metal layer (3) may be bonded onto the semiconductor chip via the adhesive layer (4). In this case, since the tensile strength of the metal layer (3) is 350 MPa or more, no pin traces occur, and the metal layer (3) and the adhesive layer (4) can be picked up from the adhesive tape (5).

<Example>

Next, in order to further clarify the effects of the present invention, examples and comparative examples will be described in detail, but the present invention is not limited to these examples.

(1) Production of adhesive tape

<Adhesive composition (1)>

An acrylic copolymer (A1) having a functional group, comprising butylacrylate, 2-ethylhexylacrylate, 2-hydroxyethylacrylate and acrylic acid, wherein the proportion of 2-ethylhexylacrylate is 50 mol%, and having a mass average molecular weight of 650,000, a glass transition temperature of -60°C, a hydroxyl value of 25 mgKOH/g and an acid value of 6 mgKOH/g, was prepared.

A mixture in which 8 parts by mass of Coronate L (manufactured by Tosoh Corporation) as a polyisocyanate was added to 100 parts by mass of the above acrylic copolymer (a-1) was dissolved in ethyl acetate and stirred to prepare an adhesive composition (1).

The following were produced as substrate films.

<Reference Film (1)>

Resin beads of an ethylene-methacrylic acid copolymer were melted at 200°C and formed into a long film having a thickness of 150 μm using an extruder to produce a base film (1). The ethylene-methacrylic acid copolymer used was Nucrel NO35C (trade name) manufactured by Mitsui DuPont Polychemical Co., Ltd.

<Adhesive Tape (1)>

The adhesive composition (1) was applied to a release liner including a polyethylene terephthalate film that had undergone a molding process so that the thickness after drying became 10 μm, dried at 110° C. for 3 minutes to form an adhesive layer, and then bonded to the base film (1) to produce an adhesive tape (1).

(2) Production of adhesive layer

<Adhesive layer (1)>

28 parts by mass of bisphenol A type phenoxy resin (manufactured by Nippon Steel Sumikin Chemical Co., Ltd., trade name "YP-50S", Mw 60,000, Tg 84°C), 55 parts by mass of solid bisphenol A type epoxy resin (manufactured by Nippon Steel Sumikin Chemical Co., Ltd., trade name "YD-011", Mw 1000, epoxy equivalent 450), 49 parts by mass of liquid bisphenol A type epoxy resin (manufactured by Nippon Steel Sumikin Chemical Co., Ltd., trade name "YD-128", Mw 400, epoxy equivalent 190), 9 parts by mass of imidazole as a curing agent (manufactured by Shikoku Chemical Industry Co., Ltd., trade name "2PHZ-PW"), silica filler (manufactured by Admatex Co., Ltd., trade name An adhesive composition solution was prepared by dissolving or dispersing 74 parts by mass of "SO-C2" (average particle size: 0.5 μm) in methyl ethyl ketone. This adhesive composition solution was applied on a release film (release liner) including a polyethylene terephthalate film having a thickness of 50 μm that was subjected to silicone release treatment, and then dried at 130°C for 5 minutes. Thereby, an adhesive layer (1) having a thickness of 20 μm was produced.

The following were prepared as metal layers.

<Metal layer (1)>

Rolled copper foil (made by UACJ Co., Ltd., tough pitch copper foil, thickness 18 ㎛, tensile strength 450 MPa, 391 W/m K)

<Metal layer (2)>

C18040 (UACJ Co., Ltd., copper alloy foil, thickness 18 ㎛, tensile strength 658 MPa, 322 W/m K)

<Metal layer (3)>

Sample A (aluminum alloy foil, thickness 20 ㎛, tensile strength 356 MPa, 110 W/m K)

<Metal layer (4)>

SUS304 (made by Nippon Steel Sumikin Materials Co., Ltd., stainless steel foil, thickness 20㎛, tensile strength 1225MPa, 16.3W/mK)

<Metal layer (5)>

F0-WS (manufactured by Furukawa Denki Kogyo Co., Ltd., copper foil, thickness 18 ㎛, tensile strength 310 MPa, 378 W/m K)

<Metal layer (6)>

1085 (made by UACJ, aluminum foil, thickness 20㎛, tensile strength 180MPa, 221W/mK)

<Sample A>

An aluminum alloy containing 0.27 mass% of Si, 0.31 mass% of Fe, 0.02 mass% of Cu, 1.1 mass% of Mn, 0.51 mass% of Mg, and 0.01 mass% of Ti, and the remainder containing Al, was melted and made into an ingot by a semi-continuous casting method, and the obtained ingot was homogenized at a temperature of 480°C for 5 h, and then hot rolled in a temperature range of 450 to 260°C to obtain a hot-rolled plate having a thickness of 3 mm. The hot-rolled plate was cold rolled to a thickness of 0.5 mm, and then an intermediate heat treatment was performed by using a rapid heating furnace to maintain the temperature at 400°C for 1 minute and cool at a cooling rate of 20°C/s. After the intermediate heat treatment, cold rolling was repeated to obtain an aluminum alloy foil having a thickness of 20 μm.

(5) Production of tape for electronic device packaging

<Example 1>

The adhesive layer (1) and the metal layer (1) formed on the above-described release liner were bonded under the conditions of a bonding angle of 120°, a pressure of 0.2 MPa, and a speed of 10 mm/s to produce a single-sided adhesive film. The adhesive tape (1) was precut into a circular shape so that it could be bonded to a ring frame, and the single-sided adhesive film was precut into a circular shape smaller than the adhesive tape (1). The adhesive layer (1) side exposed by peeling off the release treatment film of the single-sided adhesive film and the adhesive layer of the adhesive tape (1) were bonded so that the adhesive layer was exposed around the single-sided adhesive film, thereby producing a tape for an electronic device package according to Example 1 as shown in Fig. 1.

<Examples 2 to 4, Comparative Examples 1 to 2>

Tapes for electronic device packages of Examples 2 to 4 and Comparative Examples 1 to 2 were produced by the same method as Example 1, except that the combination of the adhesive tape, the adhesive composition, and the metal layer was as described in Table 1.

The following evaluations were conducted on the tapes for electronic device packages according to Examples 1 to 4 and Comparative Examples 1 to 2. The results are shown in Table 1.

(suppress pinpoint)

The metal layer and adhesive layer of the electronic device packaging tape of each sample of the above examples and comparative examples were diced to produce a 5 mm × 5 mm sized cut sample. Thereafter, the adhesive layer was irradiated with ultraviolet rays at 200 mJ/cm2 from the base film side by an air-cooled high-pressure mercury lamp (80 W/cm, irradiation distance 10 cm). A pick-up test was performed on 100 cut samples of the central portion of the electronic device packaging tape using a dice picker device (trade name "CAP-300II") manufactured by Canon Machinery Co., Ltd., to check the presence or absence of pin marks on the metal layer. In the picked-up metal layer, a sample in which no pin marks were visible to the naked eye was considered a successful sample, and the pin mark suppression success rate was calculated. In the calculated results, a sample with a success rate of 90% or more was evaluated as a good product and given an ○ rating, and a sample with a success rate of less than 90% was evaluated as a defective product and given an × rating. The evaluation results are shown in Table 1.

As shown in Table 1, the tapes for electronic device packages according to Examples 1 to 4 showed good results in the pin-mark suppression evaluation because the tensile strength of the metal layer was 356 MPa or more, which is 350 MPa or more as specified in the claims.

In contrast, the tapes for electronic device packages according to Comparative Examples 1 and 2 showed poor results in the pin-mark suppression evaluation because the tensile strength of the metal layer was less than 350 MPa.

1: Tape for electronic device packaging
2: Tape for the equipment
3: Metal layer
4: Adhesive layer
5: Adhesive tape
5a: Label section
5b: Periphery

Claims (1)

Device according to paragraph 1.

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