JP6597280B2 - Die bonding film - Google Patents

Description

  The present invention relates to a die bonding film.

  With the miniaturization and high performance of semiconductor chips, the supporting members used are also required to be miniaturized and finer. Furthermore, along with demands for miniaturization and higher density of portable devices and the like, semiconductor devices in which a plurality of semiconductor chips are stacked are being developed and mass-produced.

  Conventionally, a silver paste has been mainly used for joining a semiconductor chip and a support member for mounting a semiconductor chip. However, according to silver paste, due to the occurrence of defects during wire bonding due to protrusion or inclination of the semiconductor chip, difficulty in controlling the film thickness of the adhesive layer, and the occurrence of voids in the adhesive layer, etc. I can't cope with it. Therefore, in recent years, a film-like die bonding material (hereinafter referred to as “die bonding film”) has been used (see, for example, Patent Document 1).

  Since the capacity of a memory mounted on a portable device is increasing at an accelerating rate, the number of stacked chip stages of a semiconductor package in which a plurality of semiconductor chips are stacked tends to increase. In order to avoid an increase in the weight of the portable device, it is necessary to increase only the number of stacked semiconductor chips without increasing the volume and weight of the semiconductor package. As a result, the semiconductor chip tends to be thin, and a semiconductor chip having a thickness of 100 μm or less is used.

  In general, an 8-inch diameter semiconductor wafer is cut to a thickness of about 700 μm and then processed to a desired thickness by grinding the back surface. Conventionally, when backgrinding a semiconductor wafer thinly, a backgrinding tape that protects the wafer circuit surface is applied, and after grinding, the backgrinding tape is peeled off, and then the semiconductor wafer is applied to a die bonding film and a dicing substrate. Paste. However, as the semiconductor wafer becomes thinner, the risk of the wafer breaking during transportation increases. Therefore, a general method is to laminate the die bonding film and the dicing substrate without peeling the back grind tape and peel the back grind tape after lamination.

  However, since the upper limit of the heat resistance of the back grind tape is about 80 ° C., when adhering the die bonding film to the back surface of the wafer, it is necessary to ensure sufficient adhesion at a lamination temperature of 80 ° C. or less.

The die bonding film is generally used by any of the following methods.
(1) A die bonding film cut into an arbitrary size is attached to a substrate with wiring or a semiconductor chip, and the semiconductor chip is thermocompression bonded to the attached die bonding film.
(2) A die bonding film is attached to the entire back surface of the semiconductor wafer, and then a dicing substrate is attached to the back surface of the die bonding film, and then the semiconductor wafer is separated into pieces by a rotary blade together with the die bonding film. The obtained semiconductor chip with die bonding film is peeled off from the dicing substrate and picked up, and the picked-up semiconductor chip is thermocompression bonded to the substrate with wiring or the semiconductor chip through the die bonding film.

  Particularly, in recent years, the method (2) is mainly used for the purpose of simplifying the semiconductor device manufacturing process.

  By the way, in a semiconductor package currently used for a mobile phone, a portable music player, etc., a package in which a large number of the same semiconductor chips are stacked is mainly used for the purpose of increasing the capacity. Conventionally, the spacer type in which spacers are inserted between semiconductor chips has been the mainstream, but wire bonding to thin wafers is reduced, so the lower semiconductor chip is bonded with a die bonding film on the back of the semiconductor chip stacked on the upper stage. An embedded wire type that fills the wire has been developed.

  As the die bonding film, for example, a die bonding film having an adhesive layer containing a star-shaped acrylic copolymer has been developed (see, for example, Patent Document 2).

JP 2001-244303 A JP 2010-114433 A

  As the thickness of a semiconductor wafer is reduced, it may be difficult to pick up a semiconductor die with a die bonding film that has been separated into pieces in a general die bonding film.

  Further, the die bonding film is required to ensure the filling property (bonding wire filling property) of the die bonding film when stacking semiconductor chips and to be excellent in moisture absorption reflow resistance of the obtained semiconductor device.

  This invention is made | formed in view of the said situation, and it aims at providing the die-bonding film which is excellent in pick-up property and filling property, and is excellent in the moisture absorption reflow resistance after hardening.

  One aspect of the present invention is a block copolymer having a core part and four molecular chains linked to the core part, wherein the molecular chain has a polymer block derived from a monomer having a crosslinkable functional group. The present invention relates to a die bonding film containing a polymer.

  In the die bonding film, the block copolymer may be represented by the following formula (1).

In formula (1), X represents a carbon atom or an aromatic ring which may have a substituent, L ¹ represents a single bond or a divalent linking group, and R ¹ and R ² represent a hydrogen atom, respectively. Or a methyl group, R ³ represents a monovalent aromatic hydrocarbon group, aliphatic ester group or nitrile group, R ⁴ represents a group having a crosslinkable functional group, and Y represents a monovalent group. N represents an integer of 1 to 10000, and m represents an integer of 1 to 100. In the formula, a plurality of L ¹ , R ¹ , R ² , R ³ , R ⁴ , Y, m, and n may be the same or different.

  In the die bonding film, the Y may be a group represented by the following formula (2a).

In formula (2a), R ⁶ represents an aryl group, a pyrrolyl group, an alkoxy group, an alkyl group, or an alkyloyloxy group.

In the die bonding film, the Y may be a group represented by the following formula (i), and the L ¹ may be a linking group represented by the following formula (ii).

  The present invention also reacts a reaction product of a chain transfer agent represented by the following formula (3a) and a monomer having a polymerizable unsaturated bond with a monomer having a polymerizable unsaturated bond and a crosslinkable functional group. The present invention relates to a die bonding film containing a block copolymer.

In formula (3a), X represents a carbon atom or an aromatic ring which may have a substituent, L ² represents a single bond or a divalent linking group, R ⁵ represents an aryl group, a pyrrolyl group, An alkoxy group, an alkyl group, an alkylyloxy group, or a cyano group is shown.

  The present invention also reacts a reaction product of a chain transfer agent represented by the following formula (3b) with a monomer having a polymerizable unsaturated bond and a crosslinkable functional group, with a monomer having a polymerizable unsaturated bond. The present invention relates to a die bonding film containing a block copolymer.

  In formula (3b), X represents an aromatic ring which may have a carbon atom or a substituent.

  The die bonding film may further contain an epoxy resin and a phenol resin.

  The die bonding film may further contain an inorganic filler.

  ADVANTAGE OF THE INVENTION According to this invention, the die-bonding film which is excellent in pick-up property and filling property, and excellent in the moisture absorption reflow resistance after hardening can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In this specification, “(meth) acrylic acid” means “acrylic acid” or “methacrylic acid” corresponding thereto, and the same applies to other similar descriptions such as “(meth) acrylate”. It is.

  The die bonding film of the present embodiment is for bonding and fixing a semiconductor element and a substrate with wiring or another semiconductor element, for example. The die bonding film of this embodiment has a core part and four molecular chains connected to the core part, and the molecular chain has a polymer block derived from a monomer having a crosslinkable functional group. Contains a block copolymer. The block copolymer is a branched copolymer having a star structure (star structure) in which four molecular chains (polymer chains) extend radially starting from the core (center).

  Such a die bonding film has excellent pick-up properties and filling properties, and is excellent in moisture absorption reflow resistance after curing. That is, according to the die bonding film of this embodiment, for example, a semiconductor chip with a die bonding film can be easily picked up from a dicing substrate, and heating and pressurization (for example, a temperature of 100 to 150 ° C., a pressure of 0) (.01 to 1 MPa, heating and pressurization for 0.1 to 3 seconds), the bonding wires of the lower semiconductor chip can be completely filled, and a semiconductor device having good moisture absorption reflow resistance can be manufactured. Conceivable. Further, the die bonding film of the present embodiment, for example, when used for the purpose of stacking the upper semiconductor chip, hardly deforms the wire and can ensure the filling property of the die bonding film under the wire. As a result, the electrical characteristics of the obtained semiconductor package can be kept good.

  The present inventors presume the reason why the die bonding film of this embodiment has such an effect as follows.

  It is considered that when the weight average molecular weight of a linear polymer increases, the polymer chain becomes longer and entanglement occurs between adjacent polymer chains. Therefore, for example, from the viewpoint of improving the moisture absorption reflow resistance of the semiconductor device, when a high molecular weight linear polymer component is contained in the die bonding film, the viscosity of the die bonding film is increased, and the fluidity and pickup properties are reduced. Conceivable.

  On the other hand, since the block copolymer according to this embodiment has a structure in which four polymer chains extend radially, the polymer chain portion is not as long as a linear polymer, and entanglement is unlikely to occur. It is done. Therefore, the block copolymer according to this embodiment has a low molecular weight compared to a linear polymer having the same weight average molecular weight, and is considered to have high fluidity, so that the molecular weight is kept high. It is considered that the pickup property, the bonding wire filling property of the lower semiconductor chip, and the moisture absorption reflow resistance can be improved.

  Therefore, in the die bonding film containing the block copolymer according to the present embodiment, it is considered that both high fluidity and high reliability can be achieved, and the reliability of the semiconductor device can be improved. .

  Moreover, since the block copolymer which concerns on this embodiment has a polymer block derived from the monomer which has a crosslinkable functional group, the die-bonding film containing the said block copolymer is excellent also in the heat resistance after hardening. it is conceivable that.

  Hereinafter, the components of the die bonding film of this embodiment will be described in more detail.

[Block copolymer (hereinafter referred to as “four-chain copolymer” or “star copolymer”)]
As described above, the block copolymer according to the present embodiment has a core part and four molecular chains linked to the core part, and the molecular chain is a monomer having a crosslinkable functional group. It has a polymer block derived from it.

  From the viewpoint of further improving the heat resistance after curing of the die bonding film and decreasing the elastic modulus after curing of the die bonding film, the polymer block derived from the monomer having a crosslinkable functional group is the terminal side of the molecular chain ( It is preferably located on the side far from the core portion.

  When the polymer block derived from the monomer having a crosslinkable functional group is located at the terminal side of the molecular chain, for example, when cured together with a thermosetting component described later, the structure of the crosslinked portion becomes dense and the heat resistance further increases. While improving, it is thought that the distance between bridge | crosslinking structures is controlled and it becomes low elasticity.

  Examples of the crosslinkable functional group include an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, and an amide group. Especially, it is preferable that a crosslinkable functional group is an epoxy group from the point which can obtain the hardened | cured material excellent in heat resistance by thermosetting with an epoxy resin or a phenol resin.

  The block copolymer according to this embodiment may be, for example, an acrylic copolymer, or an acrylic rubber mainly composed of an acrylate ester, because various high-order structures and functional control are easy. May be.

  As a monomer which has a crosslinkable functional group, the monomer represented by following formula (10)-(16) is mentioned, for example. In the monomer represented by the following formulas (10) to (16), at least one of the hydrogen atoms contained in the monomer may be substituted with a fluorine atom (F).

In formula (10), R ¹⁰ represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, and R ¹¹ represents a hydrogen atom or a methyl group. Examples of the divalent aliphatic hydrocarbon group as R ¹⁰ include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group. Among these, R ¹⁰ is preferably a methylene group.

In Formula (11), R ¹² represents a C 1-5 divalent aliphatic hydrocarbon group, and R ¹³ represents a hydrogen atom or a methyl group. Examples of the divalent aliphatic hydrocarbon group as R ¹² include a methylene group, an ethylene group, a propylene group, a butylene group, and a pentylene group. Among them, R ¹² is preferably a methylene group.

In the formula (12), R ¹⁴ represents a hydrogen atom or a methyl group.

In the formula (13), R ¹⁵ represents a hydrogen atom or a methyl group, and R ¹⁶ and R ¹⁷ represent a methyl group (—CH ₃ ) or an ethyl group (—C ₂ H ₅ ).

In formula (14), R ⁵⁰ represents a hydrogen atom or a methyl group.

In formula (15), R ⁵¹ represents a hydrogen atom or a methyl group, and R ⁵² and R ⁵³ represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. Examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms as R ⁵² and ^{R 53,} for example, an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. Moreover, these alkyl groups may be substituted with a substituent. Examples of the substituent include an amino group. Among ^{them, R 52} and ^{R 53} is preferably a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms.

In Formula (16), R ²⁰ represents a hydrogen atom or a methyl group, R ²¹ represents a divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms, R ²² and R ²³ represent a hydrogen atom, carbon An aliphatic hydrocarbon group having 1 to 4 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms is shown.

The divalent aliphatic hydrocarbon group having 1 to 4 carbon atoms as R ^21, for example, alkylene groups of 1 to 4 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, and a butylene group. Among these, R ²¹ is preferably a divalent aliphatic hydrocarbon group having 1 or 2 carbon atoms.

Examples of the aliphatic hydrocarbon group having 1 to 4 carbon atoms as R ²² and R ²³ include an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group. Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms as R ²² and R ²³ include a phenyl group, a toluyl group, and a benzyl group. Among these, R ²² and R ²³ are preferably an aliphatic hydrocarbon group having 1 or 2 carbon atoms.

  From the viewpoint of increasing the elasticity of the cured product, the monomer having a crosslinkable functional group is preferably a monomer represented by the formula (10), and more preferably glycidyl (meth) acrylate.

  The specific example of the block copolymer which concerns on this embodiment contains the block copolymer represented by following formula (1).

In formula (1), X represents a carbon atom or an aromatic ring which may have a substituent, L ¹ represents a single bond or a divalent linking group, and R ¹ and R ² represent a hydrogen atom, respectively. Or a methyl group, R ³ represents a monovalent aromatic hydrocarbon group, aliphatic ester group or nitrile group, R ⁴ represents a group having a crosslinkable functional group, and Y represents a monovalent group. N represents an integer of 1 to 10000, and m represents an integer of 1 to 100. In the formula, a plurality of L ¹ , R ¹ , R ² , R ³ , R ⁴ , Y, m, and n may be the same or different.

  Examples of the aromatic ring that may have a substituent as X include a benzene ring and a naphthalene ring.

Examples of the monovalent aromatic hydrocarbon group as R ³ include an aromatic ester group and a phenyl group which may have a substituent. As a substituent which a phenyl group has, a halogen atom and a C1-C5 aliphatic hydrocarbon group are mentioned, for example.

Examples of the aliphatic ester group as R ³ include an aliphatic ester group represented by —COOR ⁴⁰ . Here, R ⁴⁰ represents a linear or branched alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, and an octyl group. Group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group and stearyl group.

From the viewpoint of easily controlling the higher-order structure and functionality, a plurality of R ³ present in the formula (1) is a butoxycarbonyl group (—COOC ₄ H ₉ ) and / or an ethoxycarbonyl group (—COOC ₂ H ₅ ). And a nitrile group. From the same viewpoint, the block copolymer preferably has a structural unit derived from butyl acrylate and / or ethyl acrylate and a structural unit derived from acrylonitrile.

Examples of the group having a crosslinkable functional group as R ⁴ include at least one crosslinkable selected from the group consisting of an epoxy group, an acryloyl group, a methacryloyl group, a hydroxyl group, a carboxyl group, an isocyanate group, an amino group, and an amide group. Examples include a group having a functional group. Specific examples of R ⁴ include a glycidyl group, a hydroxymethyl group, and a hydroxyethyl group.

Examples of the divalent linking group as L ¹ include a linking group represented by —OCOCH (CH ₃ ) — and a linking group represented by the following formula (ii).

  Examples of the monovalent group as Y include a group represented by the following formula (2a), -H, -SH, a cyanopropyl group, an alkyl group, and a group represented by the following formula (i). .

In formula (2a), R ⁶ represents an aryl group, a pyrrolyl group, an alkoxy group, an alkyl group, or an alkyloyloxy group.

That is, the monovalent group as Y may be, for example, a group represented by the formula (2a). From the viewpoint of ease of production of the block copolymer and the like, when L ¹ is a single bond or a linking group represented by —OCOCH (CH ₃ ) —, a plurality of Y are present: It may contain at least one group selected from the group consisting of a group represented by the formula (2a), -H, -SH, a cyanopropyl group, and an alkyl group. From the same viewpoint, when L ¹ is a linking group represented by formula (ii), Y is preferably a group represented by formula (i).

  (M / (n + m)) may be 0.01 to 0.1 or 0.01 to 0.08 from the viewpoint of further improving the adhesive force and the viewpoint of easily preventing gelation. It may be 0.02 to 0.06.

[Method for producing block copolymer]
Although there is no restriction | limiting in particular in the manufacturing method of the block copolymer which concerns on this embodiment, The said block copolymer is a monomer which has a chain transfer agent represented, for example by following formula (3a), and a polymerizable unsaturated bond And a reaction product of the reaction product with a monomer having a polymerizable unsaturated bond and a crosslinkable functional group, or a chain transfer agent represented by the following formula (3b), a polymerizable unsaturated bond and a crosslinkable property It can be produced by a method of reacting a reaction product of a monomer having a functional group with a monomer having a polymerizable unsaturated bond. That is, the block copolymer according to the present embodiment includes, for example, a reaction product of a chain transfer agent represented by the following formula (3a) and a monomer having a polymerizable unsaturated bond, a polymerizable unsaturated bond. And a block copolymer formed by reaction with a monomer having a crosslinkable functional group, a chain transfer agent represented by the following formula (3b), a monomer having a polymerizable unsaturated bond and a crosslinkable functional group And a block copolymer obtained by reacting the reaction product with a monomer having a polymerizable unsaturated bond. Moreover, the obtained block copolymer can be further subjected to a terminal treatment or the like, if necessary.

  The chain transfer agent represented by the formulas (3a) and (3b) (hereinafter sometimes referred to as “polyfunctional chain transfer agent”) is, for example, a RAFT agent. For example, the block copolymer according to this embodiment can be easily produced by performing RAFT (reversible addition open chain transfer) polymerization using a RAFT agent. Moreover, according to RAFT (reversible addition open chain transfer) polymerization, since the RAFT agent is incorporated into the polymer, for example, the step of removing and purifying ionic species required in atom transfer radical polymerization (ATRP) can be omitted. And the fall of the performance of the die-bonding film resulting from the residual of ionic species can be prevented. Therefore, according to the block copolymer (RAFT copolymer) obtained by such a method, it is thought that the die bonding film excellent in electrical insulation can be manufactured at low cost.

In formula (3a), L ² represents a single bond or a divalent linking group, and R ⁵ represents an aryl group, pyrrolyl group, alkoxy group, alkyl group, alkyloyloxy group or cyano group. X is as defined above. The divalent linking group as L ^2, for example, -OCOCH (CH ₃₎ - linking group represented by may be mentioned.

  X is as defined above.

  Specific examples of the chain transfer agent represented by the formula (3a) include, for example, polyfunctional chain transfer agents represented by the following formulas (I), (II) and (III).

  As a monomer which has a polymerizable unsaturated bond, the monomer represented by following formula (30)-(33) is mentioned, for example. In the monomer represented by the following formulas (30) to (33), at least one of the hydrogen atoms contained in the monomer may be substituted with a fluorine atom (F).

In Formula (30), R ³¹ represents a hydrogen atom or a methyl group, and R ³⁰ represents an aliphatic group having 1 to 20 carbon atoms or an aromatic group having 6 to 20 carbon atoms.

Examples of the aliphatic group as R ³⁰ include an alkyl group having 1 to 20 carbon atoms, an alkoxyalkyl group having 1 to 20 carbon atoms, and a hydroxyalkyl group having 1 to 20 carbon atoms. These may be linear or branched. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, cyclohexyl, heptyl, and octyl. Group, 2-ethylhexyl group, nonyl group, decyl group, dodecyl group and stearyl group. Examples of the alkoxyalkyl group include 2-methoxyethyl group, 2-ethoxyethyl group, 2-propoxyethyl group, 2-butoxyethyl group, 3-methoxypropyl group, 3-methoxybutyl group and 4-methoxybutyl group. Is mentioned. Examples of the hydroxyalkyl group include a 2-hydroxyethyl group and a 2-hydroxypropyl group.

Of these, aliphatic groups as R ³⁰ is preferably a linear alkyl group having 1 to 10 carbon atoms, more preferably a linear alkyl group having 2 to 8 carbon atoms.

Examples of the aromatic group as R ³⁰ include an aryl group having 6 to 20 carbon atoms and an aralkyl group having 7 to 20 carbon atoms. Especially, it is preferable that the said aromatic group is a C6-C10 aryl group or a C7-C11 aralkyl group. Specific examples of the aromatic group include a phenyl group, a toluyl group, and a benzyl group.

In the formula (31), R ³² represents a hydrogen atom or a methyl group.

In the formula (32), R ³³ represents a hydrogen atom or a methyl group, and R ³⁴ represents a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms as R ³⁴ include an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, and a pentyl group. As the halogen atom as R ^34, for example, a chlorine atom and a bromine atom. Among these, R ³⁴ is preferably a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and is a hydrogen atom, a halogen atom, or an aliphatic hydrocarbon group having 1 or 2 carbon atoms. It is more preferable.

In the formula (33), R ³⁵ represents a hydrogen atom or a methyl group, R ³⁶ represents a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms, and R ³⁷ , R ³⁸ and R ³⁹ represent carbon. A C1-C5 aliphatic hydrocarbon group or a C1-C5 alkoxy group is shown.

The divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms as R ^36, for example, alkylene groups of 1 to 5 carbon atoms. Examples of the alkylene group include a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. Among them, R ³⁶ is preferably a divalent aliphatic hydrocarbon group having 2 to 4 carbon atoms.

As R ^{37, R 38} and ^{R 39,} examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms, for example, an alkyl group having 1 to 5 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, and a pentyl group. The aliphatic hydrocarbon group preferably has 1 to 4 carbon atoms, more preferably 2 or 3.

As R ^{37, R 38} and ^{R 39,} the alkoxy group having 1 to 5 carbon atoms, such as methoxy group, an ethoxy group, and propoxy group and a butoxy group.

  The monomer having a polymerizable unsaturated bond is a group consisting of a monomer represented by the formula (30) and a monomer represented by the formula (31) from the viewpoints of controlling the glass transition temperature, improving cohesion, and imparting functionality. It is preferable to contain at least one selected from the group consisting of (meth) acrylic acid alkyl ester and (meth) acrylonitrile, and it is more preferable to contain at least one selected from the group consisting of (meth) acrylonitrile. When (meth) acrylic acid alkyl ester is contained, it is considered that the flexibility and the adhesion to the support member and the semiconductor element tend to increase, and when (meth) acrylonitrile is contained, the cohesive force tends to increase and the support member. In addition, it is considered that the adhesive force with a semiconductor element or the like tends to increase. From these viewpoints, the monomer having a polymerizable unsaturated bond contains at least one selected from the group consisting of methyl acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and (meth) acrylonitrile. It is more preferable to contain ethyl (meth) acrylate and / or n-butyl (meth) acrylate and (meth) acrylonitrile.

  Examples of the monomer having a polymerizable unsaturated bond and a crosslinkable functional group include monomers represented by the above formulas (10) to (16).

  The monomer having a polymerizable unsaturated bond and a crosslinkable functional group is preferably a monomer represented by the formula (10) from the viewpoint of giving a cured product that can be thermally reacted with an epoxy resin or a phenol resin and has excellent heat resistance. More preferably, it is glycidyl (meth) acrylate.

  The compounding amount of the polyfunctional chain transfer agent in the above polymerization reaction is a molar ratio (monomer / polyfunctional chain transfer) to the total molar amount of the monomer having a polymerizable unsaturated bond and the monomer having a polymerizable unsaturated bond and a crosslinkable functional group. Agent), for example, 200/1 to 20000/1.

[Radical initiator]
The above reaction (polymerization reaction) can be initiated, for example, by using a radical initiator. Examples of the radical initiator include a peroxide initiator and an azo initiator.

  Examples of the peroxide initiator include benzoyl peroxide, acetyl peroxide, lauroyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and dicumyl peroxide.

  Examples of the azo initiator include AIBN (2,2'-azobisisobutyronitrile) and V-65 (azobisdimethylvaleronitrile).

  Among them, the radical initiator is preferably AIBN (2,2'-azobisisobutyronitrile).

  The amount of the radical initiator used may be, for example, 0.5 / 1 to 10/1 in a molar ratio (polyfunctional chain transfer agent / initiator) with respect to the polyfunctional chain transfer agent.

[solvent]
The polymerization reaction may be performed in the presence of a solvent. The solvent is not particularly limited. For example, sulfoxide compounds such as dimethyl sulfoxide (DMSO); hydrocarbon compounds such as benzene and toluene; ether compounds such as diethyl ether, tetrahydrofuran and dioxane; halogenated compounds such as methylene chloride and chloroform Hydrocarbon compounds; ketone compounds such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol, propanol and isopropanol; nitrile compounds such as acetonitrile, propionitrile and benzonitrile; ester compounds such as ethyl acetate and butyl acetate; ethylene carbonate and propylene And carbonate compounds such as carbonate; and amide compounds such as dimethylformamide, dimethylacetamide, and hexamethylphosphoric amide. You may use the said solvent individually or in combination of 2 or more types.

  From the viewpoint of further improving the adhesive force and easy prevention of gelation, the compounding amount of the monomer having a polymerizable unsaturated bond and a crosslinkable functional group is such that the monomer having a polymerizable unsaturated bond, the polymerizable unsaturated bond, and 0.5-10 mass% may be sufficient on the basis of the total mass of the monomer which has a crosslinkable functional group, 1-7 mass% may be sufficient, and 2-4 mass% may be sufficient.

  When an acrylonitrile and / or amino group-containing monomer is used as a monomer having a polymerizable unsaturated bond and a monomer having a polymerizable unsaturated bond and a crosslinkable functional group, the total amount of acrylonitrile and amino group-containing monomer is the monomer used. Based on the total molar amount of the seed (the total molar amount of the monomer having a polymerizable unsaturated bond and the monomer having a polymerizable unsaturated bond and a crosslinkable functional group), for example, it may be 10 mol% or more. It may be at least mol%, at least 30 mol%, at least 40 mol%. The total amount of acrylonitrile and amino group-containing monomer may be, for example, 60 mol% or less based on the total molar amount of the monomer species used.

  The glass transition temperature (Tg) of the block copolymer according to this embodiment is the viewpoint of lowering the melt viscosity before curing of the die bonding film (B-stage state), the viewpoint of increasing the fluidity during heating, and the toughness of the cured product. From the viewpoint of improving the property, it is preferably 60 ° C. or lower, more preferably 50 ° C. or lower, and further preferably 45 ° C. or lower. In addition, the glass transition temperature may be low from the viewpoint of increasing the tack force of the die bonding film, and the glass transition temperature may be high from the viewpoint of reducing the tack.

The glass transition temperature in this specification means the value measured on condition of the following using the viscoelasticity analyzer (Rheometric company make, RSA-2).
〔Measurement condition〕
Sample size: length 12mm, width 5mm, thickness 150μm
・ Temperature range: -50 ~ 300 ℃
・ Temperature increase rate: 5 ° C / min ・ Frequency: 1 Hz
・ Mode: Tensile mode

  The weight average molecular weight of the block copolymer according to this embodiment is preferably 10,000 or more from the viewpoint of improving the adhesive strength of the cured die bonding film and increasing the reliability of the semiconductor package. Further, the weight average molecular weight of the block copolymer increases the fluidity of the die-bonding film in the B-stage state, and it is easy to fill the bonding wire of the lower chip at the time of pressure bonding, and it is difficult for unfilled voids to remain after pressure bonding. From the viewpoint of improving reliability, it is preferably 1000000 or less. From these viewpoints, the weight average molecular weight of the block copolymer is preferably 10,000 to 1,000,000, more preferably 20,000 to 500,000, and still more preferably 30,000 to 200,000.

The weight average molecular weight in this specification means the polystyrene conversion value using the calibration curve by the standard polystyrene measured on the following conditions in a gel permeation chromatography method (GPC).
[GPC conditions]
・ Pump: L-6000 (trade name, manufactured by Hitachi, Ltd.)
Column: Gelpack GL-R440, Gelpack GL-R450 and Gelpack GL-R400M (all manufactured by Hitachi Chemical Co., Ltd., trade name: 10.7 mm (diameter) × 300 mm) are connected in this order. Liquid: Tetrahydrofuran (hereinafter sometimes referred to as “THF”)
-Sample: 120 mg of sample dissolved in 5 ml of THF-Flow rate: 1.75 mL / min

  The weight average molecular weight of each polymer chain of the block copolymer according to the present embodiment is such that the adhesive strength and heat resistance of the cured die bonding film are improved, the reliability of the semiconductor package is improved, and the film composition. From the viewpoint of improving film properties, it is preferably 10,000 or more. The weight average molecular weight of each polymer chain improves the pick-up property at the time of die bonding, improves the fluidity of the die-bonding film in the B stage state, facilitates filling of the bonding wire of the lower semiconductor chip at the time of pressure bonding, and after the pressure bonding From the viewpoint of preventing unfilled voids from remaining and improving the reliability of the semiconductor package, it is preferably 300000 or less. From these viewpoints, the weight average molecular weight of each polymer chain is preferably 10,000 to 300,000, more preferably 30,000 to 200,000, and still more preferably 50,000 to 150,000.

  Here, in this specification, the weight average molecular weight of each polymer chain refers to a numerical value obtained by dividing the weight average molecular weight of the whole molecule by the number of polymer chains.

(Other ingredients)
The die bonding film of this embodiment can also contain other arbitrary components other than the said copolymer. Examples of such components include thermosetting components; fillers; coupling agents such as silane coupling agents and titanium coupling agents; leveling agents; antioxidants; and ion trapping agents.

[Thermosetting component]
As a thermosetting component, the thermosetting resin which hardens | cures with heat and exhibits an adhesive effect may be included, for example. Examples of the thermosetting resin include an epoxy resin.

  Examples of the epoxy resin include polyfunctional epoxy resins, amine-type epoxy resins (for example, glycidylamine-type epoxy resins), heterocyclic-containing epoxy resins, and alicyclic epoxy resins.

  Specific examples of the epoxy resin include bifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin; phenol novolac type epoxy resin, cresol novolac type epoxy resin (for example, o-cresol novolak) Novolak type epoxy resins such as type epoxy resins).

  As a commercial item of the said bisphenol A type epoxy resin, for example, Epicoat 807, 815, 825, 827, 828, 834, 1001, 1004, 1007 and 1009 manufactured by Japan Epoxy Resin Co., Ltd., DER-330, 301 manufactured by Dow Chemical Co., Ltd. And 361, and YD8125 manufactured by Toto Kasei Co., Ltd. (both are trade names).

  As a commercial item of the said bisphenol F type epoxy resin, Toto Kasei Co., Ltd. product YDF-8170C and YSLV-80XY (all are brand names) are mentioned, for example.

  Examples of commercially available phenol novolac epoxy resins include Epicoat 152 and 154 manufactured by Japan Epoxy Resin Co., Ltd., EPPN-201 manufactured by Nippon Kayaku Co., Ltd., and DEN-438 manufactured by Dow Chemical Co., Ltd. (both are trade names). Can be mentioned.

  As a commercial item of the said o-cresol novolak type epoxy resin, for example, Nippon Kayaku Co., Ltd. EOCN-102S, 103S, 104S, 1012, 1025 and 1027, and Toto Kasei Co., Ltd. YDCN701, 702, 703, 704 and 700-10 (both are trade names).

  As a commercial item of the said polyfunctional epoxy resin, for example, Epon 1031S manufactured by Japan Epoxy Resin Co., Ltd., Araldite 0163 manufactured by Ciba Specialty Chemicals, and Denacol EX-611, 614, 614B, 622, 512 manufactured by Nagase Chemical Co., Ltd. 521, 421, 411, and 321 (all are trade names).

  Examples of the commercially available amine type epoxy resin include Epicoat 604 manufactured by Japan Epoxy Resin Co., Ltd., YH-434 manufactured by Tohto Kasei Co., Ltd., TETRAD-X and TETRAD-C manufactured by Mitsubishi Gas Chemical Co., Ltd., and Sumitomo Chemical Co., Ltd. ELM-120 (all are trade names) is mentioned.

  As a commercial item of the said heterocyclic ring-containing epoxy resin, Ciba Specialty Chemicals Araldite PT810 and UCC ERL4234, 4299, 4221, and 4206 (all are brand names) are mentioned, for example.

  There is no restriction | limiting in particular as said epoxy resin, The thing generally known other than the above can also be used. Moreover, you may use the said epoxy resin individually or in combination of 2 or more types.

  When an epoxy resin is used as the thermosetting resin, the weight average molecular weight of the epoxy resin may be 1000 or less and 500 or less from the viewpoint of increasing the flexibility of the die bonding film in the B stage state. Also good.

  The thermosetting resin may be, for example, a bisphenol A type or bisphenol F type epoxy resin having a weight average molecular weight of 500 or less from the viewpoint of increasing the flexibility of the die bonding film in the B-stage state. From the viewpoint of improving the heat resistance of the cured product, the thermosetting resin may be, for example, a polyfunctional epoxy resin having a weight average molecular weight of 800 to 3000. From the viewpoint of achieving a high degree of flexibility and heat resistance, the thermosetting resin has a weight average molecular weight of 500 or less, a bisphenol A type or bisphenol F type epoxy resin of 50 to 90% by mass, and a weight average molecular weight of 800. -3000 polyfunctional epoxy resin 10-50 mass% can also be used together.

  From the viewpoint of increasing the tack force of the die bonding film, the epoxy resin may be, for example, a liquid epoxy resin. From the viewpoint of decreasing the tack force of the die bonding film, the epoxy resin is, for example, a solid epoxy resin. Also good.

  Examples of the liquid epoxy resin include YDF-8170C, YDCN701, 702, 703, 704 and 700-10 manufactured by Toto Kasei Co., Ltd., and Epicoat 807, 815, 825, 827, 828, 834, 1001, manufactured by Japan Epoxy Resin Co., Ltd. 1004, 1007 and 1009, DER-330, 301 and 361 manufactured by Dow Chemical Company, Epicoat 152 and 154 manufactured by Japan Epoxy Resin Co., Ltd. EPPN-201 manufactured by Nippon Kayaku Co., Ltd., and DEN-438 manufactured by Dow Chemical Company Product name).

  Examples of the solid epoxy resin include YSLV-80XY and YDF2001 manufactured by Toto Kasei Co., Ltd., and EPICLON (all trade names) manufactured by DIC Corporation.

  The thermosetting resin may be an epoxy resin from the viewpoint of further reducing the melt viscosity of the uncured film at 80 ° C. of the die bonding film.

[Curing agent]
When an epoxy resin is used as the thermosetting resin, the thermosetting component preferably further contains an epoxy resin curing agent.

  There is no restriction | limiting in particular as an epoxy resin hardening | curing agent, For example, the well-known hardening | curing agent used normally can also be used. Examples of the epoxy resin curing agent include amine compounds, polyamides, acid anhydrides, polysulfides, boron trifluoride, bisphenol compounds having two or more phenolic hydroxyl groups in one molecule, and phenol resins.

  Examples of the bisphenol compound include bisphenol A, bisphenol F, and bisphenol S.

  Examples of the phenol resin include phenol novolak resin, xylylene modified phenol resin, bisphenol A novolak resin, cresol novolac resin, phenol aralkyl resin, naphthol aralkyl resin, triphenolmethane resin, terpene modified phenol resin and dicyclopentadiene modified phenol resin. Is mentioned.

  The epoxy resin curing agent may have, for example, a low softening point from the viewpoint of further reducing the melt viscosity of the uncured film at 80 ° C. of the die bonding film.

  The softening temperature of the epoxy resin curing agent is preferably 150 ° C. or less, more preferably 140 ° C. or less, and more preferably 130 ° C. or less from the viewpoint of improving the compatibility in the varnish state before producing the die bonding film. More preferably. Specific examples of such an epoxy resin curing agent include phenol novolak resin, phenol aralkyl resin, cresol novolak resin, naphthol aralkyl resin, triphenol methane resin, terpene modified phenol resin and dicyclopentadiene modified phenol resin. Among these, the epoxy resin curing agent is preferably a phenol novolac resin or a phenol aralkyl resin.

  As a commercial item of an epoxy resin hardening | curing agent, Mitsui Chemicals Co., Ltd. Millex XLC-series and XL series, and DIC Corporation Phenolite LF series (all are brand names) are mentioned, for example.

  When an epoxy resin and an epoxy resin curing agent are used in combination as a thermosetting component, the content of the epoxy resin curing agent is the equivalent ratio of the number of hydroxyl groups of all epoxy resin curing agents to the number of epoxy groups of all epoxy resins (total epoxy resin The number of hydroxyl groups of the curing agent / the number of epoxy groups of all epoxy resins) may be, for example, 0.5 to 2.

  The thermosetting component may further contain a curing accelerator.

[Filler]
The die bonding film of the present embodiment is improved in the dicing property of the die bonding film in the B stage state, the handling property of the die bonding film is improved, the thermal conductivity is improved, the melt viscosity is adjusted, and the thixotropic property is imparted. From the above, a filler may be contained.

  As a filler, an inorganic filler is mentioned, for example.

  Examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, aluminum nitride, aluminum borate whisker, boron nitride, and crystallinity. Examples include silica, amorphous silica, and antimony oxide.

  From the viewpoint of improving thermal conductivity, the inorganic filler may be alumina, aluminum nitride, boron nitride, crystalline silica or amorphous silica, from the viewpoint of adjusting the melt viscosity and from the viewpoint of imparting thixotropic properties. , Aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina, crystalline silica or amorphous silica, which improves dicing From the viewpoint, it may be alumina or silica. In addition, there is no restriction | limiting in particular in the shape of an inorganic filler.

  Especially, it is preferable that the die bonding film of this embodiment contains an epoxy resin and a phenol resin. Moreover, it is preferable that the die bonding film of this embodiment contains an inorganic filler.

  In the die bonding film of the present embodiment, the content of the block copolymer is the sum of the block copolymer, the epoxy resin, and the curing agent from the viewpoint of further increasing the adhesive strength of the cured film of the die bonding film at 265 ° C. For example, it may be 40% by mass or less, 30% by mass or less, or 25% by mass or less with respect to the mass. The content of the block copolymer may be, for example, 5% by mass or more and 10% by mass or more with respect to the total mass of the block copolymer, the epoxy resin, and the curing agent from the viewpoint of storage stability. It may be 20% by mass or more.

  The content of the thermosetting component in the die bonding film of the present embodiment is, for example, preferably 60 to 95% by mass with respect to the total mass of the block copolymer, the epoxy resin, and the curing agent, and 70 to 90%. It is preferable that it is mass%, and it is preferable that it is 75-80 mass%.

  When the die bonding film of this embodiment contains a filler, the filler content may be, for example, 50% by mass or less with respect to the total mass of the die bonding film from the viewpoint of increasing the tack force of the die bonding film. It may be 40% by mass or less, or 35% by mass or less. The filler content is, for example, 20% by mass with respect to the total mass of the die bonding film from the viewpoint of reducing the tack force of the die bonding film and further increasing the adhesive strength of the cured film of the die bonding film at 265 ° C. The above may be sufficient, 25 mass% or more may be sufficient, and 30 mass% or more may be sufficient.

  The thickness of the die bonding film is not particularly limited, and can be appropriately determined based on the knowledge of those skilled in the art depending on the thickness of the adhesive sheet and the application (for example, a dicing tape integrated adhesive sheet). The thickness of the die bonding film may be, for example, 40 μm or more from the viewpoint of improving film formability and handleability. From the viewpoint of economy and moldability, the thickness may be, for example, 100 μm or less, 90 μm or less, or 80 μm or less. From these viewpoints, the thickness of the die bonding film is preferably 40 to 100 μm, more preferably 40 to 90 μm, and still more preferably 40 to 80 μm.

<Physical properties of die bonding film>
(Tack power)
In the die bonding film of this embodiment, the tack force of the uncured film at 40 ° C. is preferably 1500 mN or less, more preferably 1200 mN or less, and even more preferably 1000 mN or less. Here, the film uncured product refers to a B-stage film.

  When the tack force of the uncured film at 40 ° C. of the die bonding film is 1500 mN or less, it is easy to pick up without chip cracking in the pick-up process, and the die bonding films of adjacent chips adhere to each other, and a plurality of chips are simultaneously Picking up can be further reduced.

  The tack force of the uncured film at 40 ° C. of the die bonding film is measured under the following conditions using a tacking tester manufactured by Reska Co., Ltd.

(Tack force measurement conditions)
Film thickness: 40 μm, indentation speed: 2 mm / second, pulling speed: 10 mm / second, stop weight: 100 gf / cm ² , stop time: 1 second. The die bonding film sample is fixed to the 40 ° C. stage with the measurement surface facing upward, and the tack strength against a 40 ° C. probe (SUS304 having a diameter of 5.1 mm (φ)) is measured. In addition, let the surface on the side affixed to a dicing tape be a measurement surface.

(Melt viscosity)
In the die bonding film of this embodiment, the melt viscosity of the uncured film (B stage state) at 80 ° C. further improves the film fluidity and the burying property of the bonding wire of the lower chip in the die bonding process. From the viewpoint, it is preferably 10,000 Pa · s or less. When the melt viscosity is such as this, it is much easier to fill the bonding wires of the lower chip with only the crimping process, and the voids in the completed semiconductor package can be further reduced. Therefore, peeling at the time of moisture absorption reflow due to voids hardly occurs, and the reliability can be further improved. Although there is no restriction | limiting in particular in the minimum of the said melt viscosity, When the said melt viscosity is 100 Pa.s or more, it is thought that a film does not foam easily at the time of heating, such as a die bonding process or a film hardening process. From these viewpoints, the melt viscosity of the uncured film (B stage state) at 80 ° C. is preferably in the range of 100 to 10000 Pa · s, more preferably in the range of 250 to 8000 Pa · s, 500 More preferably, it is in the range of ˜5000 Pa · s.

  The 80 ° C. melt viscosity of the uncured product of the die bonding film can be measured and calculated by a parallel plate plastometer method described in Journal of Applied Physics (17) P458 (1946). For example, two uncured films (unbonded die bonding film) having a thickness of 60 μm are laminated at 40 ° C. to form a film having a thickness of about 120 μm. A sample having a diameter of 6 mm is cut out from the obtained film using a punching die. A test sample is prepared by attaching a glass slide having a thickness of 150 μm to both sides of the sample. This test sample is subjected to pressure bonding (80 ° C., 1 MPa for 3 seconds) using a COB bonder (manufactured by Hitachi Chemical Co., Ltd., AC-SC-400B). Samples before and after pressing are taken with a scanner, the area is calculated with image analysis software, and the film thickness before and after pressing is calculated.

  Subsequently, by introducing each numerical value into the following formula, the melt viscosity (η) of the uncured product of the die bonding film can be obtained.

Z ₀ (m): Die bonding film adhesive film thickness before applying load Z (m): Die bonding film adhesive film thickness after applying load V (m ³ ): Die bonding film adhesive film thickness Volume F (Pa): Applied load size t (seconds): Load applied time

(Adhesive strength)
In the die bonding film of this embodiment, the adhesive strength at 265 ° C. of the cured film (die bonding film cured product) is peeled off at the interface with the lower chip in the viewpoint of further improving the moisture absorption reflow resistance and in the reflow process after moisture absorption. Is preferably 3.5 MPa or more, more preferably 4.0 MPa or more, and still more preferably 4.5 MPa or more.

  The adhesive strength of the cured die bonding film can be measured by the following method.

  A die bonding film having a thickness of 40 μm is attached to a semiconductor wafer having a thickness of 400 μm at 60 ° C. and diced to 3.2 mm square. On the surface of the substrate (trade name “E-697FG”, manufactured by Hitachi Chemical Co., Ltd.) coated with a resist (trade name “AUS308”, manufactured by Taiyo Ink Manufacturing Co., Ltd.) Then, a sample is obtained by thermocompression bonding under the conditions of 100 ° C., 0.1 MPa, and 1 second. Thereafter, the obtained sample is cured at 100 ° C. for 1 hour, 110 ° C. for 1 hour, and 120 ° C. for 1 hour, and then cured at 175 ° C. for 5 hours to obtain a measurement sample. The measurement sample is moisture-absorbed for 168 hours under the conditions of 85 ° C. and 60 RH%. A measurement sample is placed on a hot plate set so that the surface of the resist-coated substrate is 265 ° C., and the die shear strength after being left for 30 seconds is measured. The measurement is performed using a Dage 4000 manufactured by Dage Precision Industries, under the conditions of a measurement height: 50 μm and a measurement speed: 50 μm / s.

<Production of die bonding film>
The die bonding film of this embodiment can be obtained by, for example, a method of preparing a varnish, applying the prepared varnish to a substrate, and heating and drying the applied varnish. Hereinafter, although each process is demonstrated in detail, the manufacturing method of a die-bonding film is not limited to the following method.

(1) Preparation of varnish The components of the die bonding film (for example, the block copolymer according to this embodiment; and other components such as a thermosetting component and a filler) are mixed and kneaded in an organic solvent to obtain a varnish. Prepare.

  The organic solvent used for the preparation of the varnish is not particularly limited as long as each component can be uniformly dissolved, kneaded or dispersed, and conventionally known ones can be used. Examples of such an organic solvent (solvent) include ketone compounds such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, acetone, methyl ethyl ketone, and cyclohexanone; toluene and xylene. Of these, methyl ethyl ketone and cyclohexanone are preferred because of their high drying speed and low price.

  There is no restriction | limiting in particular in the quantity of the organic solvent used for preparation of a varnish. The organic solvent is usually removed from the die bonding film by heat drying or the like. The amount of organic solvent (residual volatile matter) after the die bonding film is produced is preferably 0.01 to 3% by mass based on the total mass, and 0.01% based on the total mass from the viewpoint of heat resistance reliability. More preferably, it is -2 mass%, and it is still more preferable that it is 0.01-1.5 mass%.

  Mixing and kneading for the preparation of the varnish can be carried out by appropriately combining ordinary stirrers, crackers, triple rolls, ball mills and other dispersing machines.

(2) Coating to base material The varnish obtained in (1) is applied to the base material to form a varnish layer. Examples of the substrate include a polyethylene terephthalate film, a polyimide film, a polyester film, a polypropylene film, a polyetherimide film, a polyether naphthalate film, and a methylpentene film, and a film in which a release agent is coated. Can be mentioned.

  The varnish can be applied using, for example, an applicator automatic coating machine. The coating thickness is determined in consideration of the final die bonding film thickness, and may be, for example, 10 to 250 μm.

(3) Heat drying The varnish coated in (2) is heat-dried. The conditions for heat drying of the varnish are not particularly limited as long as the organic solvent in the varnish is sufficiently volatilized, but the varnish is usually dried by heating at 60 ° C. to 200 ° C. for 0.1 to 90 minutes. .

  After heat drying, the substrate can be removed to obtain a die bonding film (B-stage film).

  The die bonding film of this embodiment described above can be used for manufacturing a semiconductor device. More specifically, it can be used, for example, for bonding a semiconductor element and a substrate with wiring or for bonding semiconductor elements when manufacturing a semiconductor device.

  The die bonding film may be used in the form of only one layer of the die bonding film of the present embodiment, but may be used in other forms as necessary. More specifically, for example, it may be used in the form of a two-layer structure comprising the die bonding film of this embodiment and a base material, and the three layers in which the base material is arranged on both sides of the die bonding film of this embodiment. It may be used in the form of a structure, may be used in a form in which two or more die bonding films of this embodiment are laminated, and in a form in which a plurality of die bonding films of this embodiment and other die bonding films are laminated. It may be used.

  Hereinafter, as an example of a manufacturing process of a semiconductor device using the die bonding film of the present embodiment, an example using a laminate including a die bonding film (adhesive layer) and a base material will be described.

  First, the die bonding film of this embodiment and a semiconductor wafer are bonded together. As the method, for example, after the die bonding film surface on the laminate is bonded to the semiconductor wafer, the substrate is peeled off from the die bonding film, and further bonded to the adhesive layer of the die bonding film and the dicing tape, or Examples include a method in which the die bonding film surface on the laminate is bonded to the pressure-sensitive adhesive layer of the dicing tape, the substrate is peeled off from the die bonding film, and the die bonding film and the semiconductor wafer are further bonded.

  Although the semiconductor wafer is not particularly limited, the thickness of the wafer is preferably 100 μm or less, more preferably 75 μm or less, and more preferably 50 μm or less from the viewpoint of manufacturing a semiconductor device that is further excellent in moisture absorption reflow resistance. Further preferred.

  It does not specifically limit as a dicing tape, For example, plastic films, such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, a polyimide film, are mentioned. Further, the dicing tape may be subjected to surface treatment such as primer coating, UV treatment, corona discharge treatment, polishing treatment, etching treatment, etc., as necessary.

  Next, the semiconductor wafer to which the die bonding film is bonded is cut into chips of a desired size with a rotary blade of a cutting device (for example, a dicer). In this step, the die bonding film may be completely cut, but a part may remain without being cut. Generally, a method for completely cutting the die bonding film is called a full cut, and a method for leaving a part without cutting the die bonding film completely is called a half cut.

  In the case of cutting by the half-cut method, the die bonding film that remains without being cut is expanded by dicing tape (hereinafter referred to as “expand”) at the time of pickup in the pickup die bonder in the next process, and / or a push-up needle or the like at the time of pickup. By pushing up with a jig, it is also possible to divide the cut-in portion from the starting point.

  As a dicer and a rotary blade (blade) used when cutting the die bonding film, for example, those generally marketed can be used. Examples of the dicer include a full automatic dicing saw 6000 series and a semi-automatic dicing saw 3000 series manufactured by DISCO Corporation, and examples of the blade include a dicing blade NBC-ZH05 series and NBC-ZH series manufactured by DISCO Corporation. Is mentioned.

  In addition, as a method of cutting a laminate of a semiconductor wafer and a die bonding film, not only a dicer that uses a rotary blade but also a laser such as a disco full automatic laser saw 7000 series is used. A cutting method, that is, laser ablation processing or stealth dicing processing may be applied.

  The semiconductor chip with a die bonding film separated by the cutting step can be picked up by using, for example, a pickup die bonder that is generally marketed. Examples of the pickup die bonder include flexible die bonders DB-730 and DB-700 manufactured by Renesas East Japan Semiconductor, and die bonders SPA-300 and SPA-400 manufactured by Shinkawa Co., Ltd.

  As described above, after picking up the semiconductor chip with the die bonding film, the semiconductor element and the substrate with wiring or another semiconductor element were bonded by bonding the semiconductor elements to each other or the semiconductor element and the substrate with wiring. A semiconductor device having a structure can be obtained.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples.

(Synthesis of tetrafunctional chain transfer agent)
Synthesis Example 1 Synthesis of benzyldithiobenzoate type tetrafunctional chain transfer agent (CTA1)

  80 mL of a 1M THF solution of phenylmagnesium bromide (ie, 80 mmol of phenylmagnesium bromide) was added to a 500 mL two-necked eggplant flask purged with nitrogen, and 5.6 mL (94 mmol) of carbon disulfide was stirred for 15 minutes at 40 ° C. It was dripped slowly over the above. Further, 3.0 g (7 mmol) of 1,2,4,5-tetrakis (bromomethyl) benzene dissolved in 70 mL of THF was added and stirred at 50 ° C. overnight. Thereafter, the reaction mixture was added to Meyer containing 1500 mL of ice-cold water and stirred at room temperature, followed by liquid separation with diethyl ether, distilled water and saturated brine, and the organic layer was extracted. Thereafter, the solution was purified by reprecipitation with a hexane / ethyl acetate = 4/1 solution to obtain 1.5 g (2 mmol) of a red solid in a yield of 29% (formula (A)).

Synthesis Example 2 Synthesis of benzyl-1-pyrrolecarbodithioate type tetrafunctional chain transfer agent (CTA2)

  After suspending 6.3 g (264 mmol) of sodium hydride and 200 mL of dimethyl sulfoxide in a 500 mL eggplant flask purged with nitrogen, 15.0 g (224 mmol) of pyrrole was added and stirred at room temperature for 30 minutes. At this time, the solution turned from a cloudy state to a uniform light brown color. Carbon disulfide 13.8mL (229 mmol) was added here, and it stirred for 45 minutes. Immediately after the addition, heat was generated and the color of the solution changed to black. Further, 4.5 g (10 mmol) of 1,2,4,5-tetrakis (bromomethyl) benzene dissolved in 100 mL of dimethyl sulfoxide was added and stirred at room temperature for 15 hours. This solution was washed with water and diethyl ether and then dissolved in THF. This was purified by reprecipitation with a hexane / ethyl acetate = 7/3 solution to obtain 3.8 g (5.5 mmol) of a green solid in a yield of 55% (formula (B)).

(Synthesis Example 3) Synthesis of xanthate type tetrafunctional chain transfer agent (CTA3)

  Pentaerythritol (13.6 g, 100 mmol) was placed in a nitrogen-substituted 500 mL two-necked flask and dissolved in dehydrated chloroform (150 mL) and pyridine (25 mL). This solution was brought to 0 ° C., and 108 g (500 mmol) of 2-bromopropionyl bromide was slowly added dropwise. The reaction solution was returned to room temperature and reacted for 2 days, and then an aqueous hydrochloric acid solution (10%) was slowly added dropwise. The reaction solution was washed with an aqueous sodium hydrogen carbonate solution (5% by mass), and the organic layer was extracted and dried over sodium sulfate. Sodium sulfate was removed by filtration, and the solvent was removed under reduced pressure to obtain 64 g (94.7 mmol) of a tetrafunctional bromine compound. This was dissolved in 500 mL of chloroform, and 152 g (947 mmol) of potassium xanthate was added. After reacting at room temperature for 3 days, the chloroform-insoluble part was removed by filtration, and the solvent was removed under reduced pressure. After collecting 1-4 tetrafunctional CTA by column chromatography (hexane / ethyl acetate = 7/3) and removing the solvent, it was dissolved in 300 mL of chloroform, and 80.2 g (500 mmol) of potassium xanthate was added again at 60 ° C. The reaction was performed for 2 days. The chloroform insoluble part was removed by filtration, and the solvent was removed under reduced pressure. Purification was performed by column chromatography (hexane / ethyl acetate = 7/3) to obtain the desired product in a yield of 39.5% (formula (C)).

Synthesis Example 4 Synthesis of Z-core tetrafunctional chain transfer agent (CTA4)

  Pentaerythritol (13.6 g, 100 mmol) was placed in a nitrogen-substituted 2000 mL three-necked flask and dissolved in 300 mL of dimethyl sulfoxide. 33.7 g (600 mmol) of potassium hydroxide dissolved in a small amount of water was added. The reaction solution was brought to 0 ° C., and 242 mL (4000 mmol) of carbon disulfide was slowly added dropwise over 30 minutes. After returning the reaction solution to room temperature and reacting for 2 hours, 100 g (600 mmol) of methyl-2-bromopropionate was slowly added dropwise over 1 hour. After reacting for 15 hours, 1500 mL of diethyl ether was added to remove dimethyl sulfoxide and the water-soluble part. The organic layer was washed 3 times with water and dried over magnesium sulfate. The magnesium sulfate was removed by filtration, and the solvent was removed under reduced pressure. Purification was performed by column chromatography (hexane / ethyl acetate = 8/2), and the target product was obtained in a yield of 23% (formula (D)).

(Synthesis of 4-chain acrylic polymer (star acrylic copolymer))
(Synthesis Example 5)
A 500 mL separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen inlet tube was used as an initiator, azoisobutyronitrile (AIBN) (160 mg, 1 mmol), CTA3 (420 mg, 0.5 mmol), as a monomer Acrylonitrile (AN) (25 g, 480 mmol), acrylic acid-n-butyl (nBA) (32 g, 250 mmol), ethyl acrylate (EA) (25 g, 250 mmol) were added, and 43 mL of methyl ethyl ketone was further added as a solvent. Nitrogen gas was bubbled for 30 minutes for deaeration, and then the reaction was performed at 80 ° C. for 8 hours. Thereafter, glycidyl methacrylate (GMA) (2.84 g, 20 mmol) was added and reacted for another 4 hours. The reaction solution was cooled to room temperature and then dried under reduced pressure to obtain a light yellow solid polymer. (Formula (E)).

(Synthesis Example 6)
A polymer was obtained in the same manner as in Synthesis Example 5 except that CTA3 was changed to CTA1.

(Synthesis Example 7)
A polymer was obtained in the same manner as in Synthesis Example 5 except that CTA3 was changed to CTA2.

(Synthesis Example 8)
A 500 mL separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen inlet tube was used as an initiator with azoisobutyronitrile (AIBN) (160 mg, 1 mmol), CTA4 (420 mg, 0.5 mmol), methacrylic acid. Glycidyl (GMA) (2.84 g, 20 mmol) was added, and 43 mL of methyl ethyl ketone was further added as a solvent. Nitrogen gas was bubbled for 30 minutes for deaeration, and then the reaction was performed at 80 ° C. for 8 hours. Thereafter, acrylonitrile (AN) (25 g, 480 mmol), acrylic acid-n-butyl (nBA) (32 g, 250 mmol) and ethyl acrylate (EA) (25 g, 250 mmol) were added, and the reaction solution was further reacted for 4 hours. After cooling to room temperature, it was dried under reduced pressure to obtain a light yellow solid polymer.

(Comparative Synthesis Example 1)
A 500 mL separable flask equipped with a reflux condenser, a thermometer, a stirrer, and a nitrogen inlet tube was used as an initiator, azoisobutyronitrile (AIBN) (160 mg, 1 mmol), CTA3 (420 mg, 0.5 mmol), as a monomer Acrylonitrile (AN) (25 g, 480 mmol), acrylate-n-butyl (nBA) (32 g, 250 mmol), ethyl acrylate (EA) (25 g, 250 mmol), glycidyl methacrylate (GMA) (2.84 g, 20 mmol) In addition, 43 mL of methyl ethyl ketone was added as a solvent. Nitrogen gas was bubbled for 30 minutes for deaeration, and the tube was sealed and reacted at 80 ° C. under reduced pressure for 12 hours. Thereafter, the reaction solution was cooled to room temperature and then dried under reduced pressure to obtain a light yellow solid polymer.

(Examples 1-4, Comparative Example 1)
(Preparation of varnish)
Add cyclohexanone to the composition obtained by mixing the acrylic copolymer, epoxy resin, curing agent, filler, curing accelerator, and coupling agent shown below in the composition (parts by mass) shown in Table 1, and then add cyclohexanone. The mixture was stirred and degassed to prepare a varnish having a nonvolatile content of 40% by mass.

[Acrylic copolymer]
Star-type acrylic copolymer of Synthesis Example 5: (glass transition temperature 44 ° C., weight average molecular weight (Mw) 26000)
Star-type acrylic copolymer of Synthesis Example 6: (glass transition temperature 44 ° C., weight average molecular weight (Mw) 40000)
Star-type acrylic copolymer of Synthesis Example 7: (glass transition temperature 44 ° C., weight average molecular weight (Mw) 47000)
Star-type acrylic copolymer of Synthesis Example 8: (glass transition temperature 44 ° C., weight average molecular weight (Mw) 46000)
Star-type acrylic copolymer of Comparative Synthesis Example 1 (glass transition temperature 44 ° C., weight average molecular weight (Mw) 66000)
HTR-860P-3 (trade name): linear acrylic rubber (manufactured by Nagase ChemteX Corporation, glass transition temperature 25 ° C., weight average molecular weight: 800000)

[Epoxy resin]
YDF-8170C (trade name): manufactured by Tohto Kasei Co., Ltd., bisphenol F type epoxy resin, epoxy equivalent 156
YDCN-700-10 (trade name): manufactured by Toto Kasei Co., Ltd., o-cresol novolac type epoxy resin, epoxy equivalent 210

[Curing agent]
XLC-LL: Millex XLC-LL (trade name), manufactured by Mitsui Chemicals, phenol resin, hydroxyl group equivalent 175

[Filler]
SC2050-HLG (trade name): manufactured by Admatechs, silica filler dispersion, average particle size 0.5 μm

[Curing accelerator]
2PZ-CN: Curesol 2PZ-CN (trade name), manufactured by Shikoku Chemicals Co., Ltd., 1-cyanoethyl-2-phenylimidazole

[Coupling agent]
A-189: NUC A-189 (trade name), manufactured by Nippon Unicar Co., Ltd., γ-mercaptopropyltrimethoxysilane A-1160: NUC A-1160 (trade name), manufactured by Nippon Unicar Co., Ltd., γ-ureidopropyltri Ethoxysilane

(Die bonding film coating)
Using the applicator automatic coating machine (manufactured by Tester Sangyo Co., Ltd.) with the gap adjusted on each of the varnishes on a polyethylene terephthalate (PET) substrate (manufactured by Teijin DuPont Films, trade name: Mylar A53) Application (coating) was performed. The applied varnish was dried by heating in an oven at 120 ° C. for 20 minutes. Thereafter, the PET substrate was removed to obtain an uncured die bonding film in a B stage state having a film thickness of 60 μm.

(Post-curing of die bonding film)
The obtained uncured die bonding film was cured by heating at 120 ° C. for 30 minutes, 140 ° C. for 1 hour, and 175 ° C. for 2 hours to obtain a cured C-stage die bonding film. .

(Die bonding film evaluation)
Each of the obtained die bonding films of Examples 1 to 4 and Comparative Example 1 was evaluated as follows.

(1) Measurement of tack force The tack force of an uncured die bonding film (die bonding film uncured material) at 40 ° C was measured using a tacking tester manufactured by Reska Co., Ltd. The measurement conditions were as follows: film thickness: 40 μm, indentation speed: 2 mm / second, pulling speed: 10 mm / second, stop load: 100 gf / cm ² , stop time: 1 second. A die bonding film sample was fixed on a stage at 40 ° C. with the measurement surface facing up, and tack strength against a 40 ° C. probe (SUS304 having a diameter of 5.1 mm (φ)) was measured. The surface to be attached to the dicing tape was the measurement surface. The results are shown in Table 1.

(2) Measurement of Melt Viscosity The melt viscosity at 80 ° C. of the uncured product of the die bonding film was measured and calculated by the parallel plate plastometer method shown in Journal of Applied Physics (17) P458 (1946).

  Two uncured die bonding films having a thickness of 60 μm were laminated at 40 ° C. to form a film having a thickness of about 120 μm. A sample having a diameter of 6 mm was cut out from the obtained film using a punching die. A test sample was prepared by attaching a glass slide having a thickness of 150 μm on both sides of the sample. This test sample was subjected to pressure bonding (80 ° C., 1 MPa for 3 seconds) using a COB bonder (manufactured by Hitachi Chemical Co., Ltd., AC-SC-400B). Samples before and after pressing were taken with a scanner, the area was calculated with image analysis software, and the film thickness before and after pressure bonding was calculated.

  Next, the melt viscosity (η) of the uncured product of the die bonding film was calculated according to the following formula.

Z ₀ (m): Die bonding film adhesive film thickness before applying load Z (m): Die bonding film adhesive film thickness after applying load V (m ³ ): Die bonding film adhesive film thickness Volume F (Pa): Applied load size t (seconds): Load applied time

(3) Measurement of adhesive strength The adhesive strength of the cured die bonding film was measured by the following method. A die bonding film having a thickness of 40 μm was attached to a semiconductor wafer having a thickness of 400 μm at 60 ° C., and then diced to 3.2 mm square. 100 ° C. on the surface of a substrate (trade name “E-697FG”, manufactured by Hitachi Chemical Co., Ltd.) coated with a resist (trade name “AUS308”, manufactured by Taiyo Ink Manufacturing Co., Ltd.) A sample was obtained by thermocompression bonding at 0.1 MPa for 1 second.

  The obtained sample was step cured in order of 1 hour at 100 ° C., 1 hour at 110 ° C., and 1 hour at 120 ° C., and then cured at 175 ° C. for 5 hours to obtain a measurement sample. The measurement sample was moisture-absorbed for 168 hours under the conditions of 85 ° C. and 60 RH%.

  A measurement sample was placed on a hot plate set so that the surface of the resist-coated substrate was 265 ° C., and the die shear strength after being left for 30 seconds was measured. The measurement was performed using a Dage 4000 manufactured by Dage Precision Industries, under the conditions of a measurement height: 50 μm and a measurement speed: 50 μm / second. The results are shown in Table 1.

(4) Evaluation of pickup property A film having a diameter of 210 mm cut out from a die bonding film in a B-stage state is applied to a dicing tape having a thickness of 80 μm (trade name T-80MW, manufactured by Denki Kagaku Kogyo Co., Ltd.) and a die attach film mounter ( They were bonded together at room temperature (25 ° C.) using a product name DM-300-H manufactured by JCM Co., Ltd. A die bonding film / dicing tape laminate was obtained in which the open surface during coating (the opposite side of the polyethylene terephthalate film) and the dicing tape were bonded together.

  A 50 μm thick semiconductor wafer was laminated on a hot plate to the die bonding film / dicing tape laminate, and a dicing sample composed of the semiconductor wafer and the die bonding film / dicing tape laminate was produced. The hot plate surface temperature during lamination was set to 40 ° C.

Subsequently, the dicing sample was cut | disconnected using the product name full automatic dicing saw DFD-6361 by Disco Corporation. The dicing sample was cut by a single-cut method in which processing was completed with one blade, under the conditions of a blade rotation speed of 45,000 min ⁻¹ and a cutting speed of 50 mm / sec. As a blade, a product name dicing blade NBC-ZH104F-SE 27HDBB manufactured by DISCO Corporation was used. The blade height at the time of cutting was set to cut a dicing tape by 20 μm (60 μm). The dicing sample was cut so that the size of the semiconductor wafer was 10 × 10 mm to obtain a semiconductor chip with a die bonding film.

  The pick-up property of the obtained semiconductor chip with a die bonding film was evaluated using Renesas East Japan Semiconductor Co., Ltd. product name flexible die bonder DB-730. The product name RUBBER TIP 13-087E-33 (size: 10 × 10 mm) manufactured by Micromechanics is used as a collet for pickup, and the product name EJECTOR NEEDLE SEN2-83-05 (diameter: 0) manufactured by Micromechanics is used as a push-up pin. 0.7 mm, tip shape: semicircle with a diameter of 350 μm).

  Nine push-up pins were arranged with a pin center interval of 4.2 mm. The pick-up property when the semiconductor chip was picked up under the conditions of the pin push-up speed: 10 mm / second and the push-up height: 500 μm was evaluated. 100 chips were picked up continuously, and “A” was determined when no chip breakage, pickup mistakes, etc. occurred, and “C” was determined when chip breakage, pickup mistakes, etc. occurred more than one chip. The results are shown in Table 1.

(5) Bonding wire filling ability of lower chip A 100 μm thick semiconductor wafer is laminated on a hot plate to the die bonding film / dicing tape laminate obtained in (4), and the semiconductor wafer and die bonding film / dicing tape are laminated. The dicing sample comprised from the product was produced. The hot plate surface temperature during lamination was set to 40 ° C. The obtained dicing sample was cut using a product name full automatic dicing saw DFD-6361 manufactured by DISCO Corporation. The dicing sample was cut by a single-cut method in which processing was completed with one blade, under the conditions of a blade rotation speed of 45,000 min ⁻¹ and a cutting speed of 50 mm / sec. As a blade, a product name dicing blade NBC-ZH104F-SE 27HDBB manufactured by Disco Corporation was used. The blade height at the time of cutting was set to cut a dicing tape by 20 μm (60 μm). The dicing sample was cut so that the size of the semiconductor wafer was 7.5 × 7.5 mm to obtain a semiconductor chip with a die bonding film.

  The obtained semiconductor chip with a die-bonding film was pressure-bonded onto a wire-bonded semiconductor chip using a product name flexible die bonder DB-730 manufactured by Renesas East Japan Semiconductor Co., Ltd. As a bonding wire for the lower chip, a gold wire having a diameter of 25 μm was used, and the wire pitch was 200 μm. The pressing conditions of the upper chip were a hot plate temperature of 120 ° C., a load of 0.1 MPa, and a time of 1 second.

  A digital microscope (VH-6300, manufactured by Keyence Corporation) is used to determine whether or not there is a space under the bonding wire of the lower chip in the laminated body in which the semiconductor chip bonded by wire bonding and the semiconductor chip with die bonding film are bonded. The bonding wire filling property of the lower chip was evaluated. Twelve packages were observed, and “A” was determined when no void was present under the wire, and “C” was determined when void was present in one or more packages. The results are shown in Table 1.

(6) Evaluation of moisture absorption reflow resistance A laminated body in which a wire-bonded semiconductor chip and a semiconductor chip with a die bonding film were bonded by the same method as in (5) was produced. After the obtained laminate was cured at 110 ° C. for 1 hour and 120 ° C. for 1 hour, a sealing material (manufactured by Hitachi Chemical Co., Ltd., trade name: CEL-9750ZHF) was molded on the laminate, A curing process was performed at 175 ° C. for 5 hours to obtain a semiconductor package.

  After observing the peeling inside the semiconductor package and the presence or absence of voids using an ultrasonic imaging apparatus (HYE-FOCUS Scanning Acoustic Tomograph manufactured by Hitachi Construction Machinery Co., Ltd.), the semiconductor package was dried at 125 ° C. for 12 hours. The dried semiconductor package was subjected to moisture absorption treatment at 85 ° C., 60% RH and 168 hours, and then subjected to reflow treatment three times under the conditions of a maximum temperature of 265 ° C. and 30 seconds. After the reflow process, the inside of the semiconductor package was peeled off and the presence or absence of voids was observed again with an ultrasonic imaging apparatus. By observing 12 semiconductor packages after the reflow treatment, moisture absorption reflow resistance was evaluated. “A” when there is no peeling or void inside the semiconductor package, “B” when a slight change that cannot be said to be a void is observed, “B” when peeling or void exists in one or more packages Was determined as “C”. The results are shown in Table 1.

  From Table 1, according to Examples 1 to 4, a thin wafer can be picked up without cracking, and it is possible to fill the bonding wires of the lower chip in the crimping process, and the obtained semiconductor package has good moisture absorption reflow resistance. Have

  Comparative Example 1 and Comparative Example 2 had low adhesive strengths of 2.8 MPa and 2.5 MPa, and peeling occurred during the reflow treatment after moisture absorption. In Comparative Example 2, the melt viscosity was as high as 9200 Pa · s, and the filling property of the bonding wire of the lower chip was inferior, and peeling occurred due to the unfilled portion as the starting point during the reflow treatment after moisture absorption. In Comparative Example 2, the tack force at 40 ° C. was as high as 2,400 mN, and pickup failure occurred.

Claims (8)

  A block copolymer having a core part and four molecular chains linked to the core part, the molecular chain having a polymer block derived from a monomer having a crosslinkable functional group, Die bonding film. The die bonding film according to claim 1, wherein the block copolymer is represented by the following formula (1).

[In the formula (1), X represents a carbon atom or an aromatic ring which may have a substituent, L ¹ represents a single bond or a divalent linking group, and R ¹ and R ² represent hydrogen, respectively. Represents an atom or a methyl group, R ³ represents a monovalent aromatic hydrocarbon group, aliphatic ester group or nitrile group, R ⁴ represents a group having a crosslinkable functional group, and Y represents a monovalent group. Represents a group, n represents an integer of 1 to 10000, and m represents an integer of 1 to 100. In the formula, a plurality of L ¹ , R ¹ , R ² , R ³ , R ⁴ , Y, m, and n may be the same or different. ] The die bonding film according to claim 2, wherein Y is a group represented by the following formula (2a).

[In the formula (2a), R ⁶ represents an aryl group, a pyrrolyl group, an alkoxy group, an alkyl group or an alkyloyloxy group. ] The die bonding film according to claim 2, wherein Y is a group represented by the following formula (i), and L ¹ is a linking group represented by the following formula (ii).
A block copolymer obtained by reacting a reaction product of a chain transfer agent represented by the following formula (3a) and a monomer having a polymerizable unsaturated bond with a monomer having a polymerizable unsaturated bond and a crosslinkable functional group. A die bonding film containing a polymer.

[In the formula (3a), X represents a carbon atom or an aromatic ring which may have a substituent, L ² represents a single bond or a divalent linking group, and R ⁵ represents an aryl group or a pyrrolyl group. , An alkoxy group, an alkyl group, an alkylyloxy group or a cyano group. ] A block copolymer obtained by reacting a reaction product of a chain transfer agent represented by the following formula (3b) with a monomer having a polymerizable unsaturated bond and a crosslinkable functional group with a monomer having a polymerizable unsaturated bond. A die bonding film containing a polymer.

[In the formula (3b), X represents a carbon atom or an aromatic ring which may have a substituent. ]   The die bonding film according to claim 1, further comprising an epoxy resin and a phenol resin.   The die bonding film according to any one of claims 1 to 7, further comprising an inorganic filler.