JP2023092918A - Dicing die bond film - Google Patents

Abstract

To provide a dicing die bond film or the like capable of both sufficiently opening kerfs between semiconductor chips after an expanding process, and suppressing variation in kerfs depending on the part.SOLUTION: A dicing die bond film includes a dicing tape having a base layer and an adhesive layer superimposed on the base layer, and a die bond sheet overlapping the dicing tape, and the dicing tape has an elastic modulus at 120°C of 0.10 MPa or more, and the dicing tape has a heat shrinkage rate of 6% or more at 120°C.SELECTED DRAWING: Figure 1

Description

The present invention relates to a dicing die-bonding film used, for example, when manufacturing semiconductor devices.

BACKGROUND ART Conventionally, a dicing die-bonding film used in the manufacture of semiconductor devices is known. This type of dicing die-bonding film includes, for example, a dicing tape and a die-bonding sheet laminated on the dicing tape and adhered to a semiconductor wafer. The dicing tape has a base layer and an adhesive layer in contact with the die bond sheet. A dicing die-bonding film of this type is used, for example, in the following manner in the manufacture of semiconductor devices.

Generally, the method of manufacturing a semiconductor device includes a pre-process of forming a circuit surface on one side of a disk-shaped bare wafer with a highly integrated electronic circuit, and cutting out semiconductor chips from the semiconductor wafer on which the circuit surface is formed. and a post-process of assembling.

For example, the post-process includes a stealth dicing process in which a laser beam is used to form fragile portions on a semiconductor wafer for cleaving the semiconductor wafer into small semiconductor chips (dies), and a die bond sheet on the side opposite to the circuit side of the semiconductor wafer. and a mounting step of fixing the semiconductor wafer to the dicing tape via the die bond sheet, and stretching the dicing tape in the radial direction of the semiconductor wafer to cut the semiconductor wafer in which the fragile portion is formed together with the die bond sheet, An expanding process to widen the gap between adjacent semiconductor chips (dies), a pick-up process to take out the semiconductor chip with the die-bonding sheet stuck between the die-bonding sheet and the adhesive layer, and the die-bonding sheet stuck. A die bonding step of bonding a semiconductor chip in a state to an adherend via a die bonding sheet, and a curing step of thermally curing the die bonding sheet bonded to the adherend. A semiconductor device is manufactured through these processes, for example.

In the method of manufacturing a semiconductor device as described above, for example, after the expanding step is performed, the dicing tape is slackened around the plurality of cut semiconductor chips, and the adjacent semiconductor chips with the widened interval come into contact with each other. Sometimes.
On the other hand, in order to suppress the slack of the dicing tape as described above and prevent contact between adjacent semiconductor chips, the length of the dicing tape after heating is compared with the length of the dicing tape before being heated at a high temperature. A dicing die-bonding film with specified thickness is known (for example, Patent Document 1).

Specifically, in the dicing die bond film described in Patent Document 1, with respect to 100% of the first length in the MD direction of the dicing tape before heating at 100 ° C. for 1 minute, the second length in the MD direction after the heating is 95% or less.
According to the dicing die-bonding film described in Patent Document 1, it is possible to suppress the sagging of the dicing tape around a plurality of cut semiconductor chips by stretching the dicing tape. As a result, a sufficient distance (kerf) can be provided between the adjacent semiconductor chips, and contact between the semiconductor chips can be prevented.

JP 2016-115775 A

However, a dicing die-bonding film capable of not only providing a sufficient separation distance (kerf) between adjacent semiconductor chips but also suppressing variations in the above-mentioned separation distance (kerf) depending on the part has not yet been sufficiently studied. I can't say there is.

Therefore, an object of the present invention is to provide a dicing die-bonding film that can both sufficiently open kerfs between semiconductor chips after an expanding process and suppress variations in kerfs depending on the part.

In order to solve the above problems, the dicing die bond film according to the present invention includes a base layer, a dicing tape having an adhesive layer overlaid on the base layer, and a die bond sheet overlaid on the dicing tape,
The dicing tape has an elastic modulus at 120° C. of 0.10 MPa or more,
The dicing tape has a heat shrinkage rate of 6% or more at 120°C.

According to the dicing die-bonding film according to the present invention, it is possible to sufficiently open kerfs between semiconductor chips after the expanding process and to suppress variation in kerfs depending on the part.

FIG. 2 is a cross-sectional view of the dicing die-bonding film of the present embodiment cut in the thickness direction; FIG. 2 is a cross-sectional view of an example of the base layer of the dicing tape in the dicing die-bonding film of the present embodiment cut in the thickness direction. FIG. 4 is a cross-sectional view schematically showing a state of a stealth dicing step in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a stealth dicing step in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a stealth dicing step in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a back grinding step in a method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a mounting step in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a mounting step in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing an expansion step at a low temperature in the manufacturing method of the semiconductor device; FIG. 4 is a cross-sectional view schematically showing an expansion step at a low temperature in the manufacturing method of the semiconductor device; FIG. 4 is a cross-sectional view schematically showing an expansion step at a low temperature in the manufacturing method of the semiconductor device; FIG. 4 is a cross-sectional view schematically showing an expansion step at normal temperature in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing an expansion step at normal temperature in the method of manufacturing a semiconductor device; FIG. 4 is a schematic view of the state of heat treatment after an expanding step in the semiconductor device manufacturing method, viewed from one side in the thickness direction of the semiconductor chip. FIG. 4 is a cross-sectional view schematically showing a pick-up process in the method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a die bonding step and a wire bonding step in a method of manufacturing a semiconductor device; FIG. 4 is a cross-sectional view schematically showing a state of a sealing step in a method for manufacturing a semiconductor device;

An embodiment of the dicing die-bonding film according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the dicing die bond film 1 of this embodiment includes a dicing tape 20 and a die bond sheet 10 laminated on an adhesive layer 22 (described later) of the dicing tape 20 and adhered to a semiconductor wafer. .
Note that the figures in the drawings are schematic diagrams, and are not necessarily the same as the length-to-width ratio of the actual product.

In the dicing die-bonding film 1 of the present embodiment, the pressure-sensitive adhesive layer 22 is cured by being irradiated with active energy rays (for example, ultraviolet rays) when used. Specifically, in a state in which a die bond sheet 10 having a semiconductor wafer adhered to one surface thereof and an adhesive layer 22 adhered to the other surface of the die bond sheet 10 are laminated, ultraviolet rays or the like are applied to at least the adhesive layer 22. be irradiated. For example, ultraviolet rays or the like are irradiated from the side on which the base layer 21 is arranged, and the ultraviolet rays or the like pass through the base layer 21 and reach the adhesive layer 22 . The adhesive layer 22 is cured by irradiation with ultraviolet rays or the like.
Since the adhesive strength of the adhesive layer 22 can be lowered by curing the adhesive layer 22 after irradiation, the die bond sheet 10 (with the semiconductor chip adhered) can be peeled off relatively easily from the adhesive layer 22 after irradiation. can be made The die-bonding sheet 10 is to be adhered to an adherend such as a circuit board or a semiconductor chip in manufacturing a semiconductor device.

<Dicing tape for dicing die bond film>
The dicing tape 20 described above is usually a long sheet and is stored in a wound state until it is used. The dicing die-bonding film 1 of the present embodiment is stretched on an annular frame having an inner diameter slightly larger than that of the silicon wafer to be cut, and cut for use.

The dicing tape 20 described above includes a base layer 21 and an adhesive layer 22 overlaid on the base layer 21 .

The dicing tape 20 has an elastic modulus (tensile elastic modulus) at 120° C. of 0.10 MPa or more. Therefore, it is possible to suppress variation in the separation distance (kerf) between the adjacent semiconductor chips depending on the part. The reason why the variations in the separation distance (kerf) can be suppressed will be described later in detail.

The elastic modulus of the dicing tape 20 at 120° C. is preferably 0.20 MPa or more, more preferably 0.30 MPa or more. The higher elastic modulus can further reduce kerf variations. The elastic modulus may be 0.70 MPa or less. When the elastic modulus is 0.70 MPa or less, the dicing tape 20 can be thermally shrunk more effectively.

The elastic modulus of the dicing tape 20 at 120° C. can be increased, for example, by increasing the content of a resin such as polypropylene, which has a relatively high elastic modulus, in the base layer 21 . On the other hand, the elastic modulus can be reduced by lowering the content of the resin such as polypropylene, which has a relatively high elastic modulus, in the base material layer 21 .

The above elastic modulus (tensile elastic modulus) is measured under the following measurement conditions.
Measuring device: solid viscoelasticity measuring device (for example, measuring device name “RSA-G2” manufactured by TA Instruments)
Sample size: initial length 40 mm, width 10 mm
Temperature increase rate: 10°C/min,
Measurement temperature: 120°C in the temperature range from -40°C to 150°C
Distance between chucks: 20mm
Frequency: 1Hz
Strain: 0.1%
The value of the tensile storage modulus E' was taken as the above tensile modulus.

The thermal shrinkage of the dicing tape 20 at 120° C. is 6% or more. Therefore, it is possible to sufficiently open the kerf between the semiconductor chips after the expanding process. The reason why the kerf between the semiconductor chips can be sufficiently opened will be described later in detail.

The heat shrinkage rate is preferably 7% or more, more preferably 12% or more, and even more preferably 17% or more. A larger kerf between the semiconductor chips can be achieved by increasing the thermal contraction rate. The heat shrinkage rate may be 70% or less, 60% or less, or 25% or less.

The thermal shrinkage rate of the dicing tape 20 at 120° C. can be obtained by increasing the content of a relatively high thermal shrinkage resin (eg, ethylene-vinyl acetate copolymer resin) in the base layer 21, or by increasing the content of the base layer 21. It can be increased by, for example, increasing the proportion of vinyl acetate in the ethylene-vinyl acetate copolymer resin that can be contained. On the other hand, the heat shrinkage rate can be reduced by reducing the content of a resin having relatively high heat shrinkability (for example, an ethylene-vinyl acetate copolymer resin) in the base layer 21 .

The above thermal shrinkage rate is measured under the following measurement conditions. Specifically, the dicing tape 20 is cut into a long shape with a width of 30 mm and a length of 120 mm. A reference line is drawn in the width direction at each position of 10 mm/100 mm/10 mm along the longitudinal direction. Clip the end side of the marked line at one end of the cut test piece in the longitudinal direction. The dicing tape 20 is hung together with the clip in a hot air drying oven at 120° C., and heated for 1 minute in a state in which no load other than its own weight is applied to the dicing tape 20 . After heating, measure the distance between the marked lines of the specimen. The thermal shrinkage ratio is obtained by expressing the shrinkage (100 mm - the distance between the marked lines after heating) as a percentage with respect to the distance between the marked lines (100 mm) before heating.

[Base layer of dicing tape]
In this embodiment, the base material layer 21 overlaid on the pressure-sensitive adhesive layer 22 may have a single-layer structure or a laminated structure (for example, a three-layer structure).

Each layer of the base material layer 21 is, for example, a metal foil, a fiber sheet such as paper or cloth, a rubber sheet, a resin film, or the like.
Examples of the fiber sheet forming the base material layer 21 include paper, woven fabric, and non-woven fabric.
Materials for the resin film include, for example, low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polyolefins such as ethylene-propylene copolymer; ethylene-vinyl acetate copolymer (EVA), and ionomer. Resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers of ethylene such as copolymers; polyethylene terephthalate (PET), polyethylene naphthalate (PEN), Polyester such as polybutylene terephthalate (PBT); Polyacrylate; Polyvinyl chloride (PVC); Polyurethane; Polycarbonate; Polyphenylene sulfide (PPS); PEEK); polyimide; polyetherimide; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or cellulose derivative; These may be used singly or in combination of two or more.

The base material layer 21 preferably contains a polymeric material, and more preferably contains an ethylene-vinyl acetate copolymer resin and a polypropylene resin. Each layer of the base material layer 21 is preferably made of an ethylene-vinyl acetate copolymer resin or a resin film such as a polypropylene resin. Thereby, relatively high heat shrinkability and relatively high elastic modulus can be sufficiently combined.
In addition, when the base layer 21 has a resin film, the resin film may be subjected to a stretching process or the like to control deformability such as an elongation rate.

The surface of the base material layer 21 may be surface-treated in order to enhance the adhesion with the pressure-sensitive adhesive layer 22 . As the surface treatment, for example, chemical methods such as chromic acid treatment, ozone exposure, flame exposure, high-voltage shock exposure, and ionizing radiation treatment, or oxidation treatments by physical methods can be employed. Moreover, a coating treatment with a coating agent such as an anchor coating agent, a primer, or an adhesive may be applied.

The base material layer 21 preferably comprises a plurality of layers, more preferably at least three layers, even more preferably three layers.
Since the base material layer 21 has a laminated structure of a plurality of layers (for example, a three-layer structure), it is possible to laminate a layer with a higher elastic modulus and a layer with a lower elastic modulus, so that it is relatively simple. The elastic modulus of the base material layer 21 can be controlled. For example, when the elastic modulus of the base layer 21 composed of only one layer is relatively high, the semiconductor chip may be lifted or the base layer 21 may be easily broken in the expanding step. Further, for example, the stress for breaking the semiconductor chip is transmitted through the base material layer 21 and the adhesive layer 22 from the force of stretching the dicing tape 20 in the expanding process. If the elastic modulus is relatively low, the stress may be somewhat difficult to transmit.
In addition, since the base material layer 21 has a laminated structure of a plurality of layers (for example, a three-layer structure), the heat shrinkage rate of the base material layer 21 can be relatively easily controlled for the same reason as described above. .
As described above, the base material layer 21 is composed of a plurality of layers, so that the physical properties (characteristics) of each layer can be brought out. Therefore, a substrate layer composed of a plurality of layers is more likely to exhibit desired characteristics than a single-layer substrate layer.

As shown in FIG. 2, the base material layer 21 is composed of three layers in which a first base material layer 21a, a second base material layer 21b, and a third base material layer 21c are stacked. In the base layer 21 having a three-layer structure, the first base layer 21a and the third base layer 21c arranged on both sides each contain a polypropylene resin, and the first base layer 21a and the third base layer 21c It is preferable that the second base material layer 21b arranged between the layers 21c contains an ethylene-vinyl acetate copolymer resin. As a result, the base layer 21 can exhibit the properties of the polypropylene resin, which has a relatively high modulus of elasticity at high temperatures, and the properties of the ethylene-vinyl acetate copolymer resin, which has a relatively high thermal shrinkage at high temperatures. I can do it. Therefore, it is possible to fully open the kerf between the semiconductor chips after the expanding process and to suppress variations in the kerf depending on the part. In addition, in the base material layer 21, the layer which overlapped with the adhesive layer 22 is the 1st base material layer 21a, for example, and the layer farthest from the adhesive layer 22 is the 3rd base material layer 21c. The second base layer 21b is arranged between the first base layer 21a and the third base layer 21c.

The base layer 21 having a three-layer structure includes a first base layer 21a and a third base layer 21c each containing a non-elastomeric material, and a second base layer 21b disposed between these layers and containing an elastomeric material. It is preferable to have
Elastomeric materials are polymeric materials having a modulus of elasticity of 200 MPa or less at room temperature. Elastomers are polymeric materials that typically exhibit rubber elasticity at room temperature (23° C.). Non-elastomeric materials, on the other hand, are polymeric materials with elastic moduli greater than 200 MPa at room temperature.
The base layer 21 having such a three-layer laminated structure is formed, for example, by co-extrusion forming each layer and integrating the three layers.

In the base layer 21 having a three-layer structure, the ratio of the thickness of the inner layer to the total thickness of the outer layer (thickness of the second base layer 21b/total thickness of the first base layer 21a and the third base layer 21c ) is preferably 1 or more and 10 or less. Also, the thicknesses of the first base layer 21a and the third base layer 21c may be substantially the same. The ratio may be greater than or equal to 0.9 and less than or equal to 1.1.

Said non-elastomeric materials preferably comprise at least polyolefins such as low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene. The polypropylene may be a metallocene polypropylene synthesized by metallocene catalysis.

On the other hand, the elastomeric material preferably contains at least ethylene-vinyl acetate copolymer (EVA). The ethylene-vinyl acetate copolymer resin (EVA) may contain 5% by mass or more and 35% by mass or less of vinyl acetate structural units.

The thickness (total thickness) of the base material layer 21 is preferably 80 μm or more and 150 μm or less. Such values are average values of measurements at at least three randomly chosen locations. Hereinafter, the thickness of the pressure-sensitive adhesive layer 22 is also an average value measured in the same manner. When the thickness of the base material layer 21 is 80 μm or more, stress can be applied more uniformly to the entire base material layer 21, and the semiconductor wafer can be cleaved more favorably in the expanding process.

More preferably, the first base layer 21a and the third base layer 21c each independently have a thickness of 1 μm or more and 15 μm or less, and the second base layer 21b has a thickness of 70 μm or more and 120 μm or less. have. As a result, there is an advantage that the physical properties (characteristics) of each layer in the base layer 21 are more preferably reflected in the base layer 21 .

In the substrate layer 21 described above, it is preferable that at least one of the first substrate layer 21a and the third substrate layer 21c further contains an antistatic agent. As a result, the base material layer 21 can be prevented from being charged with static electricity. Therefore, it is possible to sufficiently prevent the electronic circuit in the semiconductor chip from being electrostatically damaged by the discharge of static electricity. In addition, by preventing charging, it is possible to sufficiently prevent foreign matter such as dust from adhering to the base material layer 21 .

The antistatic agent is a compound that improves the antistatic performance of each layer compared to before blending, by being blended in each layer constituting the base material layer. Examples of antistatic agents include low-molecular-weight antistatic agents such as surfactants, conductive particles such as carbon black, and polymeric antistatic agents. As the antistatic agent, a polymeric antistatic agent is preferred. A polymer-type antistatic agent has a conductive unit in its molecule that serves as a path for electric charges, is less susceptible to humidity, and is less likely to bleed out from each layer constituting the base material layer. For example, by kneading a polymer-type antistatic agent into a resin to form a resin film, and adopting this resin film for the first base layer 21a or the third base layer 21c, the base layer gradually becomes It can have stable antistatic performance.

Antistatic agents include polyolefin-polyethylene glycol copolymers, polyolefin-polyamide copolymers, polyethylene glycol-polyamide copolymers, polyethylene glycol-(meth)acrylate copolymers, polyethylene glycol-epichlorohydrin copolymers, ionomers, and , a mixture of a polymer and an ionic compound (for example, a metal salt such as a lithium salt).

On the back side of the base material layer 21 (the side on which the adhesive layer 22 is not superimposed), a release agent (release agent) such as a silicone-based resin or a fluorine-based resin is applied in order to impart releasability. Mold processing may be performed.
The substrate layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like in that active energy rays such as ultraviolet rays can be applied to the pressure-sensitive adhesive layer 22 from the back side.

The surface resistivity of the surface farthest from the adhesive layer 22 among the surfaces of the plurality of layers constituting the base material layer 21 is 1.00×10 ⁹ [Ω/sq. ] or more 1.00×10 ¹² [Ω/sq. ] is preferably below. For example, in FIG. 2, the surface resistivity of the exposed surface of the third base material layer 21c is preferably within the above numerical range. As a result, the charge can be more sufficiently released to the outside of the base material layer 21, so that the base material layer 21 can be more sufficiently prevented from being charged.

The surface resistivity is increased by increasing the amount of the antistatic agent contained in the layer having the surface on which the surface resistivity is measured, or by adopting an antistatic agent that further increases the surface resistivity. be able to. On the other hand, the surface resistivity can be reduced by reducing the amount of the antistatic agent or by using an antistatic agent that lowers the surface resistivity. A commercially available product can be used as the base material layer 21 having a desired surface resistivity.

The above surface resistivity is measured under the following measurement conditions. Specifically, the dicing tape 20 is allowed to stand for 2 hours under conditions of 23° C.±2° C. and 50% RH±5% using a high resistivity meter (for example, “Hiresta UP” manufactured by Mitsubishi Chemical Corporation). After that, the surface resistivity of the back side of the base material layer 21 (the side not covered with the adhesive layer 22) of the dicing tape is measured under the above conditions. The measurement conditions are an applied voltage of 500 V for 1 minute.

[Adhesive layer of dicing tape]
In this embodiment, the adhesive layer 22 contains, for example, an acrylic copolymer, an isocyanate compound, and a polymerization initiator.
The adhesive layer 22 may have a thickness of 5 μm or more and 40 μm or less. The shape and size of the adhesive layer 22 are usually the same as the shape and size of the base material layer 21 .

In this embodiment, the pressure-sensitive adhesive layer 22 contains an acrylic copolymer having at least alkyl (meth)acrylate units and crosslinkable group-containing (meth)acrylate units in the molecule as monomer units.
In the acrylic copolymer, some of the crosslinkable group-containing (meth)acrylate units have radically polymerizable carbon-carbon double bonds. The acrylic copolymer contains 15 mol parts or more and 60 mol parts or less of crosslinkable group-containing (meth)acrylate units with respect to 100 mol parts of alkyl (meth)acrylate units, and among the crosslinkable group-containing (meth)acrylate units contains radical polymerizable carbon-carbon double bonds.
In this specification, the notation "(meth)acrylate" represents at least one of methacrylate (methacrylic acid ester) and acrylate (acrylic acid ester). The same applies to the term "(meth)acryl".

The above acrylic copolymer has at least an alkyl (meth)acrylate unit and a crosslinkable group-containing (meth)acrylate unit in the molecule as monomer units. A monomer unit is a unit that constitutes the main chain of the acrylic copolymer. In other words, the monomeric units are derived from the monomers used to polymerize the acrylic copolymer. Each side chain in the above acrylic copolymer is contained in each monomer unit constituting the main chain.

The above alkyl (meth)acrylate units are derived from alkyl (meth)acrylate monomers. In other words, the molecular structure after the polymerization reaction of the alkyl (meth)acrylate monomer is the alkyl (meth)acrylate unit. The notation "alkyl" represents a hydrocarbon moiety ester-bonded to (meth)acrylic acid.

The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a saturated hydrocarbon or an unsaturated hydrocarbon.
The alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be a linear hydrocarbon, a branched hydrocarbon, or may contain a cyclic structure.
The number of carbon atoms in the alkyl portion (hydrocarbon) in the alkyl (meth)acrylate unit may be 8 or more and 22 or less.

The above acrylic copolymer preferably contains a long-chain alkyl (meth)acrylate unit having 8 or more carbon atoms in the alkyl portion as the alkyl (meth)acrylate unit, and the alkyl portion is a saturated hydrocarbon and has 8 or more carbon atoms. It more preferably contains long chain saturated alkyl (meth)acrylate units that are 22 or less hydrocarbons.

In the above acrylic copolymer, it is preferable that the ratio (in terms of moles) of long-chain alkyl (meth)acrylate units with 8 or more carbon atoms among all the monomer units in the molecule is the highest. It is more preferable that the proportion of alkyl (meth)acrylate units (molar conversion) is the highest. For example, long-chain alkyl (meth)acrylate units may account for 50% or more and 80% or less in terms of moles of all monomer units.

Long-chain saturated alkyl (meth)acrylate units contain neither benzene rings nor polar groups such as ether bonds (--CH ₂ --O--CH ₂ --), --OH groups, and --COOH groups in the molecule. is preferred. In long-chain saturated alkyl (meth)acrylate units, the alkyl portion is a saturated straight-chain hydrocarbon or a saturated branched-chain hydrocarbon composed of 8 to 12 carbon atoms, excluding atoms other than C and H. may be

The above acrylic copolymer includes a saturated branched alkyl (meth)acrylate unit having an alkyl portion having 8 to 10 carbon atoms, and a saturated linear alkyl (meth)acrylate unit having an alkyl portion having 12 to 14 carbon atoms. ) acrylate units as the above alkyl (meth)acrylate units.

The structure of the alkyl portion (hydrocarbon portion) of the above saturated branched alkyl (meth)acrylate unit may be a saturated branched alkyl structure, and may be an iso structure, sec structure, neo structure, or tert structure. obtain.
Specifically, saturated branched chain alkyl (meth)acrylate units include isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Examples include each unit of isostearyl (meth)acrylate. Among these, at least one of an isononyl (meth)acrylate unit and a 2-ethylhexyl (meth)acrylate unit is preferable.

The structure of the alkyl portion (hydrocarbon portion) of the saturated linear alkyl (meth)acrylate unit may be a saturated linear alkyl structure.
Specifically, saturated branched chain alkyl (meth)acrylate units include n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, tridecyl (meth)acrylate, lauryl ( Units such as meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate can be mentioned.

The acrylic copolymer described above may contain one type of alkyl (meth)acrylate unit, or may contain two or more types thereof.

The above acrylic copolymer contains at least one selected from the group consisting of 2-ethylhexyl (meth)acrylate units, isononyl (meth)acrylate units, and lauryl (meth)acrylate units as alkyl (meth)acrylate units. preferably included.

The crosslinkable group-containing (meth)acrylate unit has a hydroxy group capable of forming a urethane bond through a urethanization reaction or a polymerizable group capable of being polymerized through a radical reaction. More specifically, the crosslinkable group-containing (meth)acrylate unit has either an unreacted hydroxy group or a radically polymerizable carbon-carbon double bond as a polymerizable group. In other words, some of the crosslinkable group-containing (meth)acrylate units have unreacted hydroxy groups, and some (all others) do not have hydroxy groups and are radically polymerizable carbon-carbon double have a bond.

The above acrylic copolymer has, as a crosslinkable group-containing (meth)acrylate unit, a hydroxy group-containing (meth)acrylate unit in which a hydroxy group is bonded to an alkyl moiety having 4 or less carbon atoms. When the pressure-sensitive adhesive layer 22 contains an isocyanate compound, the isocyanate group of the isocyanate compound can easily react with the hydroxy group of the hydroxy group-containing (meth)acrylate unit.
By coexisting an acrylic copolymer having a hydroxy group-containing (meth)acrylate unit and an isocyanate compound in the adhesive layer 22, the adhesive layer 22 can be cured appropriately. Therefore, the acrylic copolymer can be sufficiently gelled. Therefore, the adhesive layer 22 can exhibit adhesive performance while maintaining its shape.

The hydroxy group-containing (meth)acrylate unit is preferably a hydroxy group-containing C2-C4 alkyl (meth)acrylate unit in which an OH group is bonded to an alkyl moiety having 2 to 4 carbon atoms. The notation "C2-C4 alkyl" represents the number of carbon atoms in the hydrocarbon moiety ester-bonded to (meth)acrylic acid. In other words, the hydroxy group-containing C2-C4 alkyl (meth)acrylic monomer is a monomer in which (meth)acrylic acid and an alcohol having 2 to 4 carbon atoms (usually a dihydric alcohol) are ester-bonded. The same applies hereinafter in the present specification.
The hydrocarbon portion of the C2-C4 alkyl is typically a saturated hydrocarbon. For example, a C2-C4 alkyl hydrocarbon moiety is a linear saturated hydrocarbon or a branched saturated hydrocarbon. The hydrocarbon portion of the C2-C4 alkyl is preferably free of polar groups containing oxygen (O), nitrogen (N), and the like.

Hydroxy group-containing C2-C4 alkyl (meth)acrylate units include, for example, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxy n-butyl (meth)acrylate, or hydroxy iso-butyl (meth)acrylate. Each unit of hydroxybutyl (meth)acrylate such as The hydroxy group (--OH group) may be bonded to the terminal carbon (C) of the hydrocarbon moiety, or may be bonded to carbon (C) other than the terminal of the hydrocarbon moiety.

The above acrylic copolymer has a polymerizable (meth)acrylate unit having a radically polymerizable carbon-carbon double bond (polymerizable unsaturated double bond) in the side chain as a crosslinkable group-containing (meth)acrylate unit. include.

Specifically, the polymerizable (meth)acrylate unit has a molecular structure in which the isocyanate group of the isocyanate group-containing (meth)acrylic monomer is urethane-bonded to the hydroxy group in the hydroxy group-containing (meth)acrylate unit described above.

By including the radically polymerizable carbon-carbon double bond of the crosslinkable group-containing (meth)acrylate unit in the acrylic copolymer, the pressure-sensitive adhesive layer 22 is exposed to active energy rays ( It can be cured by irradiation with ultraviolet light, etc.). For example, by irradiation with active energy rays such as ultraviolet rays, radicals are generated from the photopolymerization initiator, and the action of these radicals can cause the acrylic copolymers to crosslink with each other. As a result, the adhesive strength of the adhesive layer 22 before irradiation can be reduced after irradiation. Then, the die-bonding sheet 10 can be detached from the adhesive layer 22 satisfactorily.
Ultraviolet rays, radiation, and electron beams are employed as active energy rays.

Polymerizable (meth)acrylate units can be prepared by a urethanization reaction after the polymerization reaction of the acrylic copolymer. For example, after copolymerization of an alkyl (meth)acrylate monomer and a hydroxy group-containing (meth)acrylic monomer, the hydroxy group in a part of the hydroxy group-containing (meth)acrylate units and the isocyanate group of the isocyanate group-containing polymerizable monomer A polymerizable (meth)acrylate unit can be obtained by a urethanization reaction.

The above isocyanate group-containing (meth)acrylic monomer preferably has one isocyanate group and one (meth)acryloyl group in the molecule. Such monomers include, for example, 2-methacryloyloxyethyl isocyanate.

In the present embodiment, the above acrylic copolymer may contain monomer units other than the monomer units described above. For example, it may contain units such as (meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, or acrylonitrile.

In the acrylic copolymer contained in the adhesive layer 22, each unit (each structural unit) described above is subjected to NMR analysis such as ¹ H-NMR and ¹³ C-NMR, pyrolysis GC/MS analysis, and infrared spectroscopy. It can be confirmed by law. The molar ratio of the above units in the acrylic copolymer is usually calculated from the blending amount (charged amount) when the acrylic copolymer is polymerized.

The above acrylic copolymer contains 15 mol parts or more and 60 mol parts or less of crosslinkable group-containing (meth)acrylate units with respect to 100 mol parts of alkyl (meth)acrylate units, and the crosslinkable group-containing (meth)acrylate units It is preferable that 50 mol % or more and 95 mol % or less of them form urethane bonds as described above. In other words, the above acrylic copolymer contains 15 mol parts or more and 60 mol parts or less of crosslinkable group-containing (meth)acrylate units with respect to 100 mol parts of alkyl (meth)acrylate units, and contains a crosslinkable group (meth) ) It is preferable that 50 mol % or more and 95 mol % or less of the acrylate units are polymerizable (meth)acrylate units having a radically polymerizable carbon-carbon double bond. As a result, the adhesive strength between the die-bonding sheet 10 and the adhesive layer 22 before curing can be maintained, while the releasability between the die-bonding sheet 10 and the adhesive layer 22 after curing can be improved.

The above acrylic copolymer preferably contains 19 mol parts or more and 55 mol parts or less of polymerizable (meth)acrylate units with respect to 100 mol parts of alkyl (meth)acrylate units, and more preferably contains 23 mol parts or more. preferable. As a result, the adhesive strength between the die-bonding sheet 10 and the adhesive layer 22 before curing can be maintained, while the releasability between the die-bonding sheet 10 and the adhesive layer 22 after curing can be improved.

In this embodiment, the isocyanate compound that the adhesive layer 22 of the dicing tape 20 may further contain has a plurality of isocyanate groups in the molecule. By having a plurality of isocyanate groups in the molecule of the isocyanate compound, the cross-linking reaction between the acrylic copolymers in the pressure-sensitive adhesive layer 22 can proceed. Specifically, one isocyanate group of the isocyanate compound reacts with the hydroxy group of the acrylic copolymer, and the other isocyanate group reacts with the hydroxy group of another acrylic copolymer, thereby causing a cross-linking reaction via the isocyanate compound. can proceed.
The isocyanate compound may be a compound synthesized through a urethanization reaction or the like.

Examples of isocyanate compounds include diisocyanates such as aliphatic diisocyanates, alicyclic diisocyanates, and araliphatic diisocyanates.

Examples of isocyanate compounds include polymerized polyisocyanates such as diisocyanate dimers and trimers, and polymethylene polyphenylene polyisocyanates.

In addition, the isocyanate compound includes, for example, a polyisocyanate obtained by reacting an excess amount of the isocyanate compound described above with an active hydrogen-containing compound. Active hydrogen-containing compounds include active hydrogen-containing low molecular weight compounds and active hydrogen-containing high molecular weight compounds.
As the isocyanate compound, allophanatized polyisocyanate, biuretized polyisocyanate, and the like can also be used.
Said isocyanate compound can be used individually by 1 type or in combination of 2 or more types.

The above isocyanate compound is preferably a reaction product of an aromatic diisocyanate and an active hydrogen-containing low molecular weight compound. Since the reactant of the aromatic diisocyanate has a relatively slow reaction rate of the isocyanate group, excessive curing of the pressure-sensitive adhesive layer 22 containing such a reactant is suppressed. As the above isocyanate compound, those having three or more isocyanate groups in the molecule are preferred.

In this embodiment, the polymerization initiator contained in the adhesive layer 22 is a compound capable of initiating a polymerization reaction by applied heat or light energy. By including the polymerization initiator in the adhesive layer 22, the cross-linking reaction between the acrylic copolymers can be advanced when the adhesive layer 22 is given heat energy or light energy. Specifically, between acrylic copolymers having polymerizable (meth)acrylate units containing radically polymerizable carbon-carbon double bonds, a polymerization reaction between polymerizable groups is initiated to cure the pressure-sensitive adhesive layer 22. be able to. As a result, the adhesive strength of the adhesive layer 22 is reduced, and the die-bonding sheet 10 can be easily separated from the cured adhesive layer 22 in the pick-up process.
As the polymerization initiator, for example, a photopolymerization initiator or a thermal polymerization initiator is employed. A general commercial product can be used as the polymerization initiator.

The pressure-sensitive adhesive layer 22 may further contain components other than those mentioned above. Other components include, for example, tackifiers, plasticizers, fillers, anti-aging agents, antioxidants, UV absorbers, light stabilizers, heat stabilizers, antistatic agents, surfactants, and light release agents. etc. The types and amounts of other components used can be appropriately selected depending on the purpose.

<Die bond sheet of dicing die bond film>
As shown in FIG. 1, the die bond sheet 10 is overlaid on the adhesive layer 22 of the dicing tape 20 described above.

Although the thickness of the die-bonding sheet 10 is not particularly limited, it is, for example, 1 μm or more and 200 μm or less. Such thickness may be between 3 μm and 150 μm, or between 5 μm and 140 μm. In addition, when the die-bonding sheet 10 is a laminate, the above thickness is the total thickness of the laminate.

The die-bonding sheet 10 may have a single layer structure as shown in FIG. 1, for example. As used herein, a single layer means having only layers formed of the same composition. A form in which a plurality of layers formed of the same composition are laminated is also a single layer.
On the other hand, the die-bonding sheet 10 may have a multi-layer structure in which layers each formed of two or more different compositions are laminated. When the die-bonding sheet 10 has a multilayer structure, at least one layer constituting the die-bonding sheet 10 may contain a crosslinkable group-containing acrylic polymer or the like described later, and may further contain a thermosetting resin as necessary.

The peel force before curing of the adhesive layer 22 between the die bond sheet 10 and the adhesive layer 22 of the dicing tape 20 (the peel force when neither the die bond sheet 10 nor the adhesive layer 22 is cured) is , 0.30 [N/20 mm] or more, or 0.50 [N/20 mm] or more. In addition, the peel force before curing may be 3.00 [N / 20 mm] or less, may be less than 2.50 [N / 20 mm], or may be 2.00 [N / 20 mm] or less. There may be.
The release force after curing of the adhesive layer 22 between the die-bonding sheet 10 and the adhesive layer 22 of the dicing tape 20 (the peeling force after the die-bonding sheet 10 is uncured and the adhesive layer 22 is sufficiently cured ) may be 0.03 [N/20 mm] or more, or may be 0.05 [N/20 mm] or more. Moreover, it may be 0.35 [N/20 mm] or less, or may be 0.25 [N/20 mm] or less.
In order to sufficiently cure the adhesive layer 22, the adhesive layer 22 is irradiated with ultraviolet rays having an intensity of, for example, 300 mJ/cm ² .

The post-curing peel strength between the pressure-sensitive adhesive layer 22 and the die-bonding sheet 10 is measured by the following measuring method. If necessary, first, the release liner is peeled off from the die bond sheet 10 to expose one surface of the die bond sheet 10 . Next, a backing tape (for example, product name “ELP BT315” manufactured by Nitto Denko) is attached to the exposed surface of the die-bonding sheet 10 . Using a high-pressure mercury lamp manufactured by Nitto Seiki Co., Ltd. (product name “UM-810” 60 mW/cm ² ), ultraviolet light with an intensity of 300 mJ/cm ² is irradiated from the substrate layer side to cure the pressure-sensitive adhesive layer. After that, the pressure-sensitive adhesive layer 22 is cut into a size of 50 mm in width×100 mm in length to prepare a sample for measurement. The prepared measurement sample is subjected to a T-peel test using a tensile tester (eg, product name “AUTOGRAPH AGX-V” manufactured by Shimadzu Corporation). The test conditions are a temperature of 23° C. and a tensile speed of 300 mm/min. In addition, the peeling force before curing of the adhesive layer 22 is obtained by cutting the adhesive layer 22 from the adhesive layer 22 before curing so as to have a size of 20 mm in width and 100 mm in length, except for the preparation of a sample for measurement. is measured in the same manner as described above.

For example, in the molecule of the acrylic copolymer contained in the pressure-sensitive adhesive layer 22, increasing the ratio of alkyl (meth)acrylate units having a small number of carbon atoms in the alkyl portion, or increasing the ratio of hydroxyl group-containing (meth)acrylate units By increasing it, the above peeling force can be increased. On the other hand, for example, in the molecule of the acrylic copolymer contained in the adhesive layer 22, increasing the proportion of alkyl (meth)acrylate units having a large number of carbon atoms in the alkyl portion, or increasing the proportion of hydroxyl group-containing (meth)acrylate units By lowering the ratio, the above peel force can be reduced.

The die-bonding sheet 10 contains a crosslinkable group-containing acrylic polymer having in its molecule a crosslinkable group that causes a crosslink reaction by a heat curing treatment. Such a crosslinkable group-containing acrylic polymer is a polymer compound in which at least a (meth)acrylate monomer is polymerized.

The above crosslinkable group-containing acrylic polymer usually has the above crosslinkable groups in side chains. The above crosslinkable group-containing acrylic polymer may have the above crosslinkable group at the end of the side chain. The above crosslinkable group-containing acrylic polymer may have the above crosslinkable group on at least one of both ends of the main chain.

The crosslinkable group that the above-mentioned crosslinkable group-containing acrylic polymer has in the molecule is not particularly limited as long as it is a functional group that causes a crosslink reaction by heat curing treatment.

Examples of crosslinkable groups include hydroxy groups and carboxy groups. These crosslinkable groups are capable of cross-linking reactions with epoxy groups or isocyanate groups. For example, the crosslinkable group-containing acrylic polymer having at least one of a hydroxy group or a carboxyl group in the molecule is crosslinked with a compound having an epoxy group or an isocyanate group in the molecule (for example, an epoxy resin described later). can react.

Moreover, examples of the crosslinkable group include an epoxy group and an isocyanate group. These crosslinkable groups can cause a crosslink reaction with a hydroxy group or a carboxy group. For example, the crosslinkable group-containing acrylic polymer having at least one of an epoxy group and an isocyanate group in the molecule can be combined with a compound having at least one of a hydroxy group and a carboxy group in the molecule (for example, a phenol resin described later). A cross-linking reaction can occur between

In the present embodiment, the crosslinkable group-containing acrylic polymer contained in the die bond sheet 10 preferably contains at least one of a hydroxy group and a carboxy group as a crosslinkable group. Thereby, the die-bonding sheet 10 can be adhered to the adherend more satisfactorily.

In the above-mentioned crosslinkable group-containing acrylic polymer, the ratio of the constituent units of the crosslinkable group-containing monomer may be 0.1% by mass or more and 60.0% by mass or less, or 0.5% by mass or more and 40.0% by mass. % by mass or less, 1.0% by mass or more and 30.0% by mass or less, or 3.0% by mass or more and 20.0% by mass or less.
When the above ratio is 0.1% by mass or more, the hardening of the die-bonding sheet 10 can proceed more sufficiently when the die-bonding sheet 10 is heat-hardened. On the other hand, when the above ratio is 60.0% by mass or less, the crosslinkability of the crosslinkable group-containing acrylic polymer can be moderately suppressed, and the stability over time can be enhanced.
The structural unit is a structure derived from each monomer after polymerization of the monomer (for example, 2-ethylhexyl acrylate, hydroxyethyl acrylate, etc.) when polymerizing the crosslinkable group-containing acrylic polymer. The same applies hereinafter.

The crosslinkable group-containing acrylic polymer can be synthesized, for example, by a general polymerization method using a radical polymerization initiator.

Among the structural units in the molecule, the crosslinkable group-containing acrylic polymer preferably contains the most structural units of alkyl (meth)acrylate monomers in terms of mass ratio. Examples of the alkyl (meth)acrylate monomers include C1 to C18 alkyl (meth)acrylate monomers having an alkyl group (hydrocarbon group) of 1 to 18 carbon atoms.

Examples of alkyl (meth)acrylate monomers include saturated linear alkyl (meth)acrylate monomers and saturated branched alkyl (meth)acrylate monomers.

Saturated linear alkyl (meth)acrylate monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-heptyl (meth)acrylate, n - octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, tridecyl (meth)acrylate, lauryl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate ) acrylates and the like. The number of carbon atoms in the linear alkyl group portion is preferably 2 or more and 8 or less.
Saturated branched alkyl (meth)acrylate monomers include isoheptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and the like. In addition, the alkyl group portion may have any of iso structure, sec structure, neo structure, or tert structure.

The crosslinkable group-containing acrylic polymer contains structural units derived from a crosslinkable group-containing monomer copolymerizable with an alkyl (meth)acrylate monomer.
In the present embodiment, the crosslinkable group-containing acrylic polymer is an acrylic polymer obtained by copolymerizing at least an alkyl (meth)acrylate monomer and a crosslinkable group-containing monomer. In other words, the crosslinkable group-containing acrylic polymer has a structure in which structural units of alkyl (meth)acrylate monomers and structural units of crosslinkable group-containing monomers are connected in random order.

Examples of the crosslinkable group-containing monomer include carboxy group-containing (meth)acrylic monomers, acid anhydride (meth)acrylic monomers, hydroxyl group (hydroxyl group)-containing (meth)acrylic monomers, epoxy group (glycidyl group)-containing (meth)acrylic monomers, ) functional group-containing monomers such as acrylic monomers, isocyanate group-containing (meth)acrylic monomers, sulfonic acid group-containing (meth)acrylic monomers, phosphoric acid group-containing (meth)acrylic monomers, acrylamide, and acrylonitrile. The crosslinkable group-containing monomer may have an ether group, an ester group, or the like in the molecule.

The crosslinkable group-containing acrylic polymer is preferably
At least one crosslinkable group selected from the group consisting of carboxy group-containing (meth)acrylic monomers, hydroxy group-containing (meth)acrylic monomers, epoxy group-containing (meth)acrylic monomers, and isocyanate group-containing (meth)acrylic monomers containing monomers;
It is a copolymer with an alkyl (meth)acrylate (especially an alkyl (meth)acrylate in which the alkyl portion has 8 or less carbon atoms).

Carboxy group-containing (meth)acrylic monomers include, for example, (meth)acrylic acid and mono(2-(meth)acryloyloxyethyl)succinate monomers. In addition, the carboxy group may be arranged at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion.
Examples of hydroxy group-containing (meth)acrylic monomers include hydroxyethyl (meth)acrylate monomers, hydroxypropyl (meth)acrylate monomers, and hydroxybutyl (meth)acrylate monomers. In addition, the hydroxy group may be arranged at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion.
Epoxy group-containing (meth)acrylic monomers include, for example, glycidyl (meth)acrylate monomers, 4-hydroxybutyl (meth)acrylate glycidyl ether, and the like. In addition, the epoxy group may be arranged at the terminal portion of the monomer structure, or may be bonded to a hydrocarbon other than the terminal portion.
Isocyanate group-containing (meth)acrylic monomers include, for example, 2-methacryloyloxyethyl isocyanate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate, 2-acryloyloxyethyl isocyanate, 2-(2-methacryloyloxyethyloxy) and ethyl isocyanate.

The die-bonding sheet 10 may contain components other than the above-described crosslinkable group-containing acrylic polymer. For example, the die-bonding sheet 10 may further contain at least one of a thermosetting resin and a thermoplastic resin other than the crosslinkable group-containing acrylic polymer.

Examples of thermosetting resins include epoxy resins, phenol resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. As the thermosetting resin, one type or two or more types are employed.

Examples of the epoxy resin include bisphenol A type, bisphenol F type, bisphenol S type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol AF type, biphenyl type, naphthalene type, fluorene type, phenol novolak type, ortho Epoxy resins of cresol novolac type, trishydroxyphenylmethane type, tetraphenylolethane type, hydantoin type, trisglycidyl isocyanurate type, or glycidylamine type are included.

Phenolic resins can act as curing agents for epoxy resins. Examples of phenolic resins include novolac-type phenolic resins, resol-type phenolic resins, and polyoxystyrenes such as polyparaoxystyrene.
Examples of the novolak-type phenol resin include phenol novolak resin, phenol aralkyl resin, cresol novolak resin, tert-butylphenol novolak resin, nonylphenol novolak resin, and the like.
The hydroxyl group equivalent [g/eq] of the phenol resin may be, for example, 90 or more and 220 or less.
As the phenol resin, only one kind or two or more kinds are adopted.

In the present embodiment, the die-bonding sheet 10 may contain the above-mentioned crosslinkable group-containing acrylic polymer and thermosetting resin that crosslink with each other.

For example, the die-bonding sheet 10 may contain an epoxy group-containing acrylic polymer as the crosslinkable group-containing acrylic polymer and a phenolic resin as the thermosetting resin. As a result, the epoxy group of the crosslinkable group-containing acrylic polymer and the hydroxy group of the phenolic resin undergo a cross-linking reaction to sufficiently cure the die-bonding sheet 10 .

Examples of thermoplastic resins other than the crosslinkable group-containing acrylic polymer that can be contained in the die-bonding sheet 10 include natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer. Polymers, ethylene-acrylate copolymers, polybutadiene resins, polycarbonate resins, thermoplastic polyimide resins, polyamide resins such as 6-polyamide resins and 6,6-polyamide resins, phenoxy resins, crosslinkable functional groups in the molecule Examples thereof include acrylic resins that do not contain such resins, saturated polyester resins such as PET and PBT, polyamide-imide resins, and fluorine resins.
As the thermoplastic resin, only one kind or two or more kinds are adopted.

In the die-bonding sheet 10, the content of the crosslinkable group-containing acrylic polymer is preferably 8% by mass or more and 100% by mass or less, more preferably 30% by mass or more, and still more preferably 40% by mass or more. .

In the die bond sheet 10, 100 parts by mass of the organic components excluding the filler (for example, the above-mentioned crosslinkable group-containing acrylic polymer, thermosetting resin, curing catalyst, silane coupling agent, dye), the above-mentioned crosslinkable The content of the group-containing acrylic polymer is preferably 15 parts by mass or more and 100 parts by mass or less, more preferably 40 parts by mass or more and 95 parts by mass or less, and still more preferably 60 parts by mass or more. The elasticity and viscosity of the die-bonding sheet 10 can be adjusted by changing the content of the thermosetting resin in the die-bonding sheet 10 .
On the other hand, the content of the thermosetting resin may be 40 parts by mass or less with respect to 100 parts by mass of the organic component.

The die-bonding sheet 10 may or may not contain a filler. By changing the amount of filler in the die bond sheet 10, the elasticity and viscosity of the die bond sheet 10 can be adjusted more easily. Furthermore, the physical properties of the die-bonding sheet 10, such as electrical conductivity, thermal conductivity, and elastic modulus, can be adjusted.

Fillers include inorganic fillers and organic fillers. An inorganic filler is preferable as the filler.
Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, boron nitride, crystalline silica and amorphous silica. Examples include fillers containing silica such as pure silica. Inorganic filler materials include simple metals such as aluminum, gold, silver, copper and nickel, and alloys. Fillers such as aluminum borate whiskers, amorphous carbon black, and graphite may also be used. The shape of the filler may be various shapes such as spherical, needle-like, and flake-like. As the filler, only one of the above fillers, or two or more of them are employed.

When the die-bonding sheet 10 contains a filler, the content of the filler may be 50% by mass or less, 40% by mass or less, or 30% by mass or less of the total mass of the die-bonding sheet 10. good too. In addition, the content rate of the said filler may be 5 mass % or more, for example.

The die-bonding sheet 10 may contain other components as necessary. Examples of the other components include curing catalysts, flame retardants, silane coupling agents, ion trapping agents, and dyes.
Examples of flame retardants include antimony trioxide, antimony pentoxide, and brominated epoxy resins.
Silane coupling agents include, for example, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like.
Examples of ion trapping agents include hydrotalcites, bismuth hydroxide, benzotriazole, and the like.
Only one kind or two or more kinds are adopted as the other additives.

The die-bonding sheet 10 preferably contains the above-described crosslinkable group-containing acrylic polymer, thermosetting resin, and filler in that the elasticity and viscosity can be easily adjusted.

The dicing die-bonding film 1 of the present embodiment may include a release liner that covers one side of the die-bonding sheet 10 (the side where the die-bonding sheet 10 does not overlap the pressure-sensitive adhesive layer 22) before use. The release liner is used to protect the die bond sheet 10 and is peeled off immediately before the die bond sheet 10 is attached to an adherend (eg, a semiconductor wafer).
As the release liner, for example, a plastic film or paper surface-treated with a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide-based release agent can be used.
A release liner can be used as a support material for supporting the die bond sheet 10 . A release liner is preferably used when the die-bonding sheet 10 is overlaid on the pressure-sensitive adhesive layer 22 . Specifically, the die bond sheet 10 is laminated on the adhesive layer 22 while the release liner and the die bond sheet 10 are laminated, and the die bond sheet 10 is attached to the adhesive layer 22 by peeling off (transferring) the release liner after the lamination. can be stacked.

Next, a method for manufacturing the die-bonding sheet 10 and the dicing die-bonding film 1 of this embodiment will be described.

<Manufacturing method of dicing die-bonding film>
The method for manufacturing the dicing die-bonding film 1 of this embodiment includes:
a step of producing a die bond sheet 10;
A step of making a dicing tape 20;
and a step of superposing the manufactured die bond sheet 10 and the dicing tape 20 on each other.

<Process of producing die bond sheet>
The process of producing the die-bonding sheet 10 includes:
a resin composition preparation step of preparing a resin composition for forming the die-bonding sheet 10;
and a die bond sheet forming step of forming the die bond sheet 10 from the resin composition.

In the resin composition preparation step, for example, the above-mentioned crosslinkable group-containing acrylic polymer is mixed with either an epoxy resin, a phenol resin, a curing catalyst, or a solvent, and each resin is dissolved in the solvent to obtain a resin A composition is prepared. By varying the amount of solvent, the viscosity of the composition can be adjusted. In addition, as these resins, commercially available products can be used.

In the die-bonding sheet forming step, for example, the resin composition prepared as described above is applied to a release liner. The coating method is not particularly limited, and for example, common coating methods such as roll coating, screen coating, gravure coating and the like are employed. Next, if necessary, the applied composition is solidified by solvent removal treatment, curing treatment, or the like to form the die bond sheet 10 .

<Process of producing dicing tape>
The process of making a dicing tape is
A synthesis step of synthesizing an acrylic copolymer;
The adhesive layer 22 is produced by volatilizing the solvent from the adhesive composition containing the acrylic copolymer, the isocyanate compound, the polymerization initiator, the solvent, and other components that are appropriately added depending on the purpose. A pressure-sensitive adhesive layer preparation process to
A substrate layer producing step for producing the substrate layer 21;
a laminating step of laminating the base layer 21 and the pressure-sensitive adhesive layer 22 by bonding the pressure-sensitive adhesive layer 22 and the base layer 21 together.

In the synthesis step, for example, a C8-C12 alkyl (meth)acrylate monomer having an alkyl portion having 8 to 12 carbon atoms and a hydroxy group-containing (meth)acrylic monomer are radically polymerized to form an acrylic copolymer intermediate. synthesize the body.
Radical polymerization can be performed by a general method. For example, an acrylic copolymer intermediate can be synthesized by dissolving each of the above monomers in a solvent, stirring the solution while heating, and adding a polymerization initiator. Polymerization may be carried out in the presence of a chain transfer agent to control the molecular weight of the acrylic copolymer.
Next, the hydroxy groups of some of the hydroxy group-containing (meth)acrylate units contained in the acrylic copolymer intermediate and the isocyanate groups of the isocyanate group-containing polymerizable monomer are combined by a urethanization reaction. As a result, part of the hydroxy group-containing (meth)acrylate units become polymerizable (meth)acrylate units containing radically polymerizable carbon-carbon double bonds.
A urethanization reaction can be performed by a general method. For example, the acrylic copolymer intermediate and the isocyanate group-containing polymerizable monomer are stirred while heating in the presence of a solvent and a urethanization catalyst. As a result, the isocyanate groups of the isocyanate group-containing polymerizable monomer can be urethane-bonded to some of the hydroxy groups of the acrylic copolymer intermediate.

In the pressure-sensitive adhesive layer preparation step, for example, an acrylic copolymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare a pressure-sensitive adhesive composition. By varying the amount of solvent, the viscosity of the composition can be adjusted. The adhesive composition is then applied to the release liner. As the coating method, a general coating method such as roll coating, screen coating, gravure coating, or the like is employed. By subjecting the applied composition to desolvation treatment, solidification treatment, or the like, the applied adhesive composition is solidified, and the adhesive layer 22 is produced.

In the substrate layer producing step, the substrate layer can be produced by forming a film by a general method. Examples of film-forming methods include 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 dry lamination method, and the like. A co-extrusion method may be employed. A commercially available film or the like may be used as the base material layer 21 .

In the lamination step, the pressure-sensitive adhesive layer 22 and the base material layer 21 are laminated on the release liner. Note that the release liner may be in a state of being superimposed on the adhesive layer 22 before use.
In addition, in order to promote the reaction between the cross-linking agent and the acrylic copolymer, and to promote the reaction between the cross-linking agent and the surface portion of the base layer 21, after the lamination step, 48 A time aging treatment step may be performed.

Through these steps, the dicing tape 20 can be manufactured.

<Process of Overlapping Die Bonding Sheet and Dicing Tape>
In the step of overlapping the die bond sheet 10 and the dicing tape 20, the die bond sheet 10 is attached to the adhesive layer 22 of the dicing tape 20 manufactured as described above.

In such attachment, the release liners are peeled off from the adhesive layer 22 of the dicing tape 20 and the die bond sheet 10, respectively, and the die bond sheet 10 and the adhesive layer 22 are attached together so that they are in direct contact. For example, they can be attached by pressing. The temperature for bonding is not particularly limited, and is, for example, 30° C. or higher and 50° C. or lower, preferably 35° C. or higher and 45° C. or lower. The linear pressure during bonding is not particularly limited, but is preferably 0.1 kgf/cm or more and 20 kgf/cm or less, more preferably 1 kgf/cm or more and 10 kgf/cm or less.

The dicing die-bonding film 1 manufactured as described above through the steps described above is used, for example, as an auxiliary tool for manufacturing a semiconductor device (semiconductor integrated circuit). A method of manufacturing a semiconductor device (a method of using a dicing die-bonding film) will be described below.

<Method for manufacturing a semiconductor device (method for using a dicing die-bonding film when manufacturing a semiconductor device)>
In a method of manufacturing a semiconductor device, semiconductor chips are generally cut out from a semiconductor wafer having a circuit surface and assembled. At this time, the dicing die-bonding film of this embodiment is used as a manufacturing aid.

The method for manufacturing the semiconductor device of this embodiment includes:
A cutting step of cutting a semiconductor wafer on which a circuit surface is formed into semiconductor chips (dies);
and a pick-up step of peeling the die-bonding sheet attached to the adhesive layer of the dicing die-bonding film from the adhesive layer together with the semiconductor chip.

In the method of manufacturing a semiconductor device according to the present embodiment, the cutting step includes, for example, forming a fragile portion with a laser beam inside a semiconductor wafer to which a back grind tape is attached, and cutting the semiconductor wafer into a semiconductor chip (die). A stealth dicing process for preparing for processing, a backgrinding process for grinding the semiconductor wafer to which the backgrinding tape is attached to reduce the thickness, and one side of the thinned semiconductor wafer (for example, the circuit side). ) is attached to the die bond sheet 10, and the semiconductor wafer is fixed to the dicing tape 20 via the die bond sheet 10; a step of expanding the space between the adjacent semiconductor chips, and a pickup step of removing the semiconductor chip (die) with the die-bonding sheet 10 adhered by peeling the die-bonding sheet 10 from the adhesive layer 22 . have.
The method for manufacturing a semiconductor device of the present embodiment further includes a die bonding step of bonding the die bonding sheet 10 attached to the semiconductor chip to an adherend, a curing step of curing the die bonding sheet 10 bonded to the adherend, It has a wire bonding step of electrically connecting the electrodes of the electronic circuit of the semiconductor chip and the adherend with wires, and a sealing step of sealing the semiconductor chip and wires on the adherend with a thermosetting resin. .

The stealth dicing process is a process in a so-called SDBG (Stealth Dicing Before Grinding) process. In the stealth dicing process, as shown in FIGS. 3A to 3C, a fragile portion is formed inside the semiconductor wafer W for cleaving the pattern wafer on which the circuit surface is formed into semiconductor chips. Specifically, first, a back grind tape G is attached to the circuit surface of the semiconductor wafer W (see FIG. 3A). Next, with the backgrinding tape G attached, the semiconductor wafer W is ground (pre-backgrinding) with a grinding pad K until it has a predetermined thickness (see FIG. 3B). Then, a weakened portion is formed inside the semiconductor wafer W by irradiating the semiconductor wafer W with a reduced thickness with a laser beam (see FIG. 3C).

A half-cutting process may be performed instead of the stealth dicing process. The half-cut process is a process in a so-called DBG (Dicing Before Grinding) process.
In the half-cut process, grooves are formed in the semiconductor wafer to be processed into semiconductor chips (dies) by cutting the semiconductor wafer, and then the semiconductor wafer is ground to reduce its thickness.
Specifically, in the half-cutting process, a half-cutting process is performed to cut a semiconductor wafer having a circuit surface formed thereon into semiconductor chips (dies). More specifically, a wafer processing tape is attached to the surface of the semiconductor wafer opposite to the circuit surface. A dividing groove is formed in the semiconductor wafer while the wafer processing tape is attached to the semiconductor wafer. While the back grind tape is attached to the grooved surface, the wafer processing tape that was attached first is peeled off.

The dicing die-bonding film of the present embodiment is preferably used in the SDBG (Stealth Dicing Before Grinding) process or DBG (Dicing Before Grinding) process for cutting a semiconductor wafer to manufacture semiconductor chips as described above.

In the backgrinding process, as shown in FIG. 3D, the semiconductor wafer W to which the backgrinding tape G is adhered is subjected to further grinding processing, and the thickness of the semiconductor chip (die) produced by subsequent cutting processing is reduced. The thickness of the semiconductor wafer W is reduced until For example, the half-cut semiconductor wafer W may be ground until it has a predetermined thickness so as not to be separated. When the grinding process is performed in this manner, the semiconductor wafer W is cleaved into semiconductor chips and the die bond sheet 10 is also cleaved at the same time as the semiconductor wafer W is cleaved into semiconductor chips by the subsequent expansion process (particularly the low-temperature expansion process). On the other hand, the half-cut semiconductor wafer W may be ground until it is individualized. When the grinding process is performed in this way, the gap between the adjacent semiconductor chips is widened and the die bond sheet 10 is cleaved in the later expanding process (especially the low temperature expanding process).

In the mounting process, the semiconductor wafer W is fixed to the dicing tape 20 as shown in FIGS. 4A and 4B. Specifically, while attaching the dicing ring R to the adhesive layer 22 of the dicing tape 20, the semiconductor wafer W whose thickness has been reduced by the cutting process as described above is attached to the exposed surface of the die-bonding sheet 10 (see FIG. 4A). ). Subsequently, the back grind tape G is peeled off from the semiconductor wafer W (see FIG. 4B).

Before the expanding step, the die-bonding sheet 10 may be cut by, for example, laser light irradiation. Specifically, when the semiconductor wafer W is singulated by the above-described cutting process, the die bond sheet 10, which is not yet cleaved while overlapping the semiconductor chips formed by the singulation of the semiconductor wafer, may be cut by irradiation with a laser beam. good. After that, the interval between adjacent semiconductor chips may be widened by an expanding process.

In the expanding step, as shown in FIGS. 5A to 5C, the distance between the semiconductor chips X produced by cutting is widened. Specifically, after attaching the dicing ring R to the adhesive layer 22 of the dicing tape 20, it is fixed to the holder H of the expanding device (see FIG. 5A). The dicing die-bonding film 1 is stretched so as to spread in the plane direction by pushing up the dicing die-bonding film 1 from the lower side of the dicing die-bonding film 1 (see FIG. 5B). Thereby, the semiconductor wafer W is cleaved under specific temperature conditions. The above temperature conditions are, for example, -20 to 0°C, preferably -15 to 0°C, more preferably -10 to -5°C. By lowering the push-up member U, the expanded state is canceled (see FIG. 5C, low-temperature expansion step up to this point).
Furthermore, in the expanding step, as shown in FIGS. 6A and 6B, the dicing tape 20 is stretched under higher temperature conditions (for example, 10° C. to 25° C.) so as to expand the area. As a result, after cutting, the adjacent semiconductor chips X are pulled apart in the plane direction of the film surface to further widen the kerf (separation distance between adjacent semiconductor chips) (normal temperature expansion step).
When performing the DBG process described above, in the expanding process, a method of cutting the die-bonding sheet 10 at a low temperature may be adopted, or a method of cutting the die-bonding sheet 10 with a laser may be adopted. When the die-bonding sheet is cut with a laser, an expanding process may be performed at a lower temperature after the die-bonding sheet 10 is cut.

In this embodiment, the dicing tape 20 is stretched in the plane direction by the expanding process. At this time, if the dicing tape 20 is not heat-treated around the group of small pieces of semiconductor chips, the dicing tape 20 in the portion (central portion) overlapping the many semiconductor chips shrinks back to its original shape. . In order to prevent the dicing tape 20 from shrinking, the dicing tape 20 is heat-treated at a temperature of about 120° C. around the large number of small semiconductor chip groups. In other words, the portion of the dicing tape 20 that does not overlap with the semiconductor chips and is along the outer periphery of the group of semiconductor chips is heat-treated at a temperature of about 120.degree. For example, as shown in FIG. 7, the heat treatment is carried out using a heater S or the like that can move in the circumferential direction along the outer periphery of a large number of small semiconductor chip groups. Therefore, in the heat-treated portion of the dicing tape 20, a portion with a higher temperature and a portion with a lower temperature can exist at the same time. As shown in FIG. 7, for example, in the belt-shaped portion surrounding the outer periphery of the semiconductor chip group, which is the portion of the dicing tape 20 to be heat-treated, one portion in the longitudinal direction has a higher temperature, and the other portion has a higher temperature. can be lower.

Before the pick-up process, for example, the adhesive layer 22 overlapping the base material layer 21 is subjected to a curing treatment by irradiating the adhesive layer 22 with ultraviolet rays from the base material layer 21 side (curing treatment process).

In the pick-up process, as shown in FIG. 8, the semiconductor chip X to which the die bond sheet 10 is stuck is peeled off from the adhesive layer 22 of the dicing tape 20 . Specifically, the pin member P is raised to push up the semiconductor chip X to be picked up through the dicing tape 20 . The pushed-up semiconductor chip X is held by a suction jig J.

In the die-bonding step, the semiconductor chip X with the die-bonding sheet 10 attached is adhered to the adherend Z. As shown in FIG. In the die-bonding process, for example, as shown in FIG. 9, the semiconductor chips X to which the die-bonding sheet 10 is attached may be stacked multiple times.

In the curing step, in order to increase the reaction activity of the crosslinkable groups (for example, epoxy groups) in the above-described crosslinkable group-containing acrylic polymer contained in the die bond sheet 10 to advance the curing of the die bond sheet 10, the temperature is set at 100° C. or higher and 180° C., for example. Heat treatment is performed at a temperature of ℃ or less.

In the wire bonding process, the semiconductor chip X (die) and the adherend Z are connected by wires L while being heated (see FIG. 9, for example).

In the sealing step, as shown in FIG. 10, the semiconductor chip X and the die bond sheet 10 are sealed with a thermosetting resin M such as epoxy resin. In the sealing step, in order to advance the curing reaction of the thermosetting resin M, heat treatment is performed at a temperature of, for example, 100° C. or higher and 180° C. or lower.

In the semiconductor industry in recent years, with further progress in integration technology, thinner semiconductor chips (for example, thickness of 20 μm or more and 50 μm or less) and thinner die bond sheets (for example, 1 μm or more and 40 μm or less, preferably 7 μm) below, more preferably 5 μm or less thickness).

In the above-described method of manufacturing a semiconductor device (method of using a dicing die-bonding film), in the expanding step (particularly, the room-temperature expanding step), the dicing tape 20 is stretched with a strong force in the surface direction so as to expand the area. Further, after stretching the dicing tape 20, part of the dicing tape 20 is heat-treated at about 120° C. to shrink it. Specifically, the portion of the dicing tape 20 along the outer circumference of the group of semiconductor chips (peripheral portion), which does not overlap with the large number of small pieces of semiconductor chips, is shrunk by the heat treatment as described above. When the heat shrinkage rate is 6% or more, the portion (peripheral portion) heated by the heat treatment described above is likely to shrink. Shrinkage of the dicing tape 20 in the portion (central portion) overlapping the large number of small pieces of semiconductors is suppressed to the extent that the outer peripheral portion shrinks easily. In other words, the stretched dicing tape 20 can be prevented from shrinking in the direction opposite to the stretched direction in the portion (central portion) that overlaps with a large number of semiconductor chips. Therefore, it is possible to suppress narrowing of the intervals between a large number of small pieces of semiconductor chips.
On the other hand, if the heat shrinkability of the dicing tape 20 at 120° C. is not controlled, for example, if the dicing tape 20 does not shrink much due to heat treatment, the central portion of the dicing tape 20 is relatively likely to shrink. As a result, the space between many small pieces of semiconductor chips is narrowed. Therefore, it may be difficult to sufficiently open the kerf between the semiconductor chips after the expanding process.
In the dicing die-bonding film of the present embodiment, the dicing tape 20 has a thermal shrinkage rate of 6% or more at 120° C., so that the kerf between the semiconductor chips can be sufficiently opened after the expanding step as described above.

Further, the heat treatment of the dicing tape 20 as described above is carried out by moving a heater or the like along the outer periphery of a large number of small semiconductor chip groups, as shown in FIG. 7, for example. Specifically, two heaters or the like move along the outer circumference of a large number of semiconductor chip groups so as to make a half turn. In such a heat treatment method, among the heated portions, there are portions that are heated first and portions that are heated last. Therefore, a temperature difference occurs between the portion heated first and the portion heated last. In other words, the temperature of the first heated portion is cooled as the heater moves away, so that when the heat treatment is completed, the temperature of the last heated portion will be lower. In general, the higher the temperature, the lower the elastic modulus of the material, so the elastic modulus of the hot portion, for example, about 120° C., before cooling can be much lower than the elastic modulus of the cold portion. Therefore, the high-temperature portion of the dicing tape 20 whose elastic modulus has decreased due to the high temperature may not necessarily be able to sufficiently suppress the force that causes the dicing tape 20 to shrink in the direction opposite to the stretching direction. On the other hand, since the elastic modulus of the cold portion of the dicing tape 20 is high, the above shrinkage force can be sufficiently suppressed. In such a state, the portion of the dicing tape 20 that overlaps the large number of semiconductor chip groups tends to shrink unevenly. Therefore, there is a possibility that the kerf in a large number of semiconductor chip groups once spread out will vary.
On the other hand, in the dicing die bond film of the present embodiment, the dicing tape 20 has an elastic modulus of 0.10 MPa or more at 120° C., and the elastic modulus is relatively high even at a high temperature of 120° C. It can sufficiently suppress the force that tries to shrink. The temperature of 120° C. is close to the temperature at which a portion of the dicing tape 20 stretched in the expanding step is heat-treated as described above and shrunk, for example. As described above, the heat treatment at this time is performed, for example, by sequentially heating portions to be heated along the outer periphery of a large number of small semiconductor chip groups with a heater or the like. Therefore, the part where the temperature rises due to heating and the part where the temperature drops after heating are mixed. Even in such a situation, the dicing tape 20 of the present embodiment has a relatively high elastic modulus at a high temperature portion (for example, a portion at 120° C.). The power to try is suppressed enough. Therefore, in the central portion of the dicing tape 20 that overlaps with a large number of semiconductor chip groups, it is possible to suppress variation in contraction force depending on the portion. Therefore, it is possible to suppress variations in the kerf depending on the region after the expanding process.

The dicing die-bonding film of the present embodiment is as exemplified above, but the present invention is not limited to the dicing die-bonding film exemplified above.
That is, various forms used in general dicing die-bonding films can be employed as long as the effects of the present invention are not impaired.

Matters disclosed by this specification include the following.
(1)
A base layer, a dicing tape having an adhesive layer superimposed on the base layer, and a die bond sheet superimposed on the dicing tape,
The dicing tape has an elastic modulus at 120° C. of 0.10 MPa or more,
A dicing die-bonding film, wherein the dicing tape has a heat shrinkage rate of 6% or more at 120°C.
(2)
The dicing die-bonding film according to (1) above, wherein the base layer contains an ethylene-vinyl acetate copolymer resin and a polypropylene resin.
(3)
The dicing die-bonding film according to (1) or (2) above, wherein the base layer is composed of a plurality of layers.
(4)
The dicing die-bonding film according to (3) above, wherein the base layer is composed of three or more layers.
(5)
The base layer is composed of three layers in which a first base layer, a second base layer, and a third base layer are stacked,
The first base layer and the third base layer arranged on both sides respectively contain a polypropylene resin, and the second base layer arranged between the first base layer and the third base layer The dicing die-bonding film according to (4) above, wherein contains an ethylene-vinyl acetate copolymer resin.
(6)
The dicing die-bonding film according to (5) above, wherein at least one of the first base layer and the third base layer further contains an antistatic agent.
(7)
The antistatic agent is a polyolefin-polyethylene glycol copolymer, polyolefin-polyamide copolymer, polyethylene glycol-polyamide copolymer, polyethylene glycol-(meth)acrylate copolymer, polyethylene glycol-epichlorohydrin copolymer, ionomer, And the dicing die-bonding film according to (6) above, which is at least one selected from the group consisting of a mixture of a polymer and an ionic compound (for example, a metal salt such as a lithium salt).
(8)
The above ( The dicing die-bonding film according to any one of 5) to (7).
(9)
The surface resistivity of the surface farthest from the pressure-sensitive adhesive layer among the surfaces of the plurality of layers constituting the base material layer is 1.00×10 ⁹ [Ω/sq. ] or more 1.00×10 ¹² [Ω/sq. ] The dicing die-bonding film according to any one of the above (3) to (8), wherein:
(10)
The dicing die-bonding film according to any one of (1) to (9) above, wherein the pressure-sensitive adhesive layer contains an acrylic copolymer, an isocyanate compound, and a polymerization initiator.
(11)
Any one of the above (1) to (10), wherein the die-bonding sheet includes a crosslinkable group-containing acrylic polymer having a crosslinkable group in the molecule that causes a crosslinkable reaction by thermosetting, a thermosetting resin, and a filler. The dicing die-bonding film according to 1.

Next, the present invention will be described in more detail by way of experimental examples, but the present invention is not limited to these.

A dicing tape was manufactured as follows. A dicing die-bonding film was produced by bonding this dicing tape to a die-bonding sheet.

<Preparation of dicing tape>
[Adhesive layer]
(Raw material monomer for acrylic copolymer)
・2-hydroxyethyl acrylate (HEA): 20 parts by mass ・2-ethylhexyl acrylate (2EHA): 100 parts by mass

Each of the above raw materials was placed in a reaction vessel equipped with a condenser, nitrogen inlet, thermometer and stirrer. 0.2 parts by weight of azobisisobutyronitrile (AIBN) was used as a thermal polymerization initiator with respect to a total of 100 parts by weight of the monomers. Ethyl acetate was added as a reaction solvent so that the concentration of all monomers reached a predetermined concentration (for example, 35% by mass). A polymerization reaction treatment was carried out in a nitrogen stream at 62° C. for a predetermined time (eg, 3 hours) and further at 75° C. for a predetermined time (eg, 4 hours) to obtain an acrylic copolymer intermediate.
In each example and each comparative example, the monomer concentration and polymerization time during polymerization are as shown in Table 2, respectively.

2-Methacryloyloxyethyl isocyanate (hereinafter also referred to as MOI) was added to the liquid containing the acrylic copolymer intermediate prepared as described above so as to be 80 mol % in terms of mol based on the total amount of HEA. . Further, 0.03% by mass of dibutyltin dilaurate was added as a reaction catalyst based on the MOI addition amount. After that, an addition reaction treatment (urethanization reaction treatment) was performed in an air current at 50° C. for 12 hours to obtain an acrylic copolymer.
Next, the following ingredients were added to 100 parts by mass of the acrylic copolymer to prepare an adhesive solution.
- Photopolymerization initiator: 2.5 parts by mass (product name "Omnirad 127D", manufactured by IGM)
・ Polyisocyanate compound: 0.75 parts by mass (product name “Takenate D-101E”, manufactured by Mitsui Chemicals)
· Antioxidant: 0.01 parts by mass (product name "Irganox 1010", manufactured by BASF Japan)
The pressure-sensitive adhesive solution prepared as described above was applied onto the treated surface of a silicone-treated PET release liner and dried by heating at 120° C. for 2 minutes to form a pressure-sensitive adhesive layer having a thickness of 10 μm.

[Base material layer]
Using the products shown below as raw materials and having the composition shown in Tables 1 and 2, a substrate layer in which three layers or two layers were laminated, or a single layer substrate layer was produced. The composition of the single-layer base material layer is described in the column of the first base material layer.
(polyolefin resin)
・ PO-1: Product name “Wintek WXK1233” (manufactured by Japan Polypropylene Corporation)
Polyolefin resin (metallocene polypropylene resin)
・ PO-2: Product name “Vistamaxx3980FL” (manufactured by Exxon Mobil Chemical Company)
Polyolefin resin (propylene elastomer resin, 9% ethylene content)
・ PO-3: Product name “Zelas 5053YT13” (manufactured by Mitsubishi Chemical Corporation)
Polyolefin resin (olefin thermoplastic elastomer resin)
・ PO-4: Product name “Zelas ZT536” (manufactured by Mitsubishi Chemical Corporation)
Polyolefin resin (olefin thermoplastic elastomer resin)
(ethylene-vinyl acetate resin)
・EVA-1: Product name “EVAFLEX P1007” (manufactured by Mitsui Dow Polychemicals)
Ethylene-vinyl acetate copolymer resin (contains 10% by mass of vinyl acetate)
・ EVA-2: Product name “Ultrasen 626” (manufactured by Tosoh Corporation)
Ethylene-vinyl acetate copolymer resin (contains 15% by mass of vinyl acetate)
・EVA-3: Product name “EVAFLEX V1030” (manufactured by Mitsui Dow Polychemicals)
Ethylene-vinyl acetate copolymer resin (contains 10% by mass of vinyl acetate)
・EVA-4: ethylene-vinyl acetate copolymer resin (manufactured by Mitsui Dow Polychemicals)
(low density polyethylene resin)
・ PE: Product name “Sumikasen F723-P” (manufactured by Sumitomo Chemical Co., Ltd.)
(ionomer resin)
・ IO: Made by Mitsui Dow Polychemicals (polyurethane resin)
・PU: manufactured by BASF (antistatic agent)
・ AS: Product name “Perestat 230” (manufactured by Sanyo Kasei Co., Ltd.)
Polyolefin-polyethylene glycol copolymer

(Molding of base material layer)
A substrate layer was molded using an extrusion T-die molding machine. The extrusion temperature was 190°C. The two-layer type or three-layer laminate type substrate layers were integrated by co-extrusion from a T-die. After the integrated base material layer (laminate) was sufficiently solidified, the base material layer was wound into a roll and stored.
The thickness of each layer constituting the base material layer is as shown in Tables 1 and 2, respectively.

[Lamination of Adhesive Layer and Base Layer]
Subsequently, the pressure-sensitive adhesive layer and the substrate layer prepared as described above were laminated together and stored at 50° C. for 24 hours to produce a dicing tape.

<Production of die bond sheet>
・Acrylic polymer: 100 parts by mass (product name “PARACRON KG-8001”, mass average molecular weight: 1,200,000, glass transition temperature Tg: 9 ° C., containing epoxy group, manufactured by Negami Kogyo Co., Ltd.)
・ Phenolic resin: 3 parts by mass (product name “MEHC-7851SS”, solid at 23 ° C., manufactured by Meiwa Kasei Co., Ltd.)
・ Silica filler: 10 parts by mass (product name “SE2050-MCV”, average particle size 500 nm, manufactured by Admatechs)
Each of the above raw materials was added to a predetermined amount of methyl ethyl ketone and mixed to prepare an adhesive composition solution having a total solid concentration of 12% by mass. Next, an applicator was used to apply the adhesive composition onto the silicone release-treated surface of the PET release liner having the silicone release-treated surface to form a coating film. This coating film was dried by heating at 130° C. for 2 minutes to prepare a die-bonding sheet having a thickness of 10 μm on a PET release liner.

(Examples 1-3, Comparative Examples 1-5)
[Manufacturing of dicing die-bonding film]
Tables 1 and 2 show each configuration of the base layer of the die-bonding sheet. A circular die-bonding sheet having a diameter of 330 mm was punched out from the die-bonding sheet. A dicing die-bonding film was manufactured by laminating a circular die-bonding sheet and a dicing tape at room temperature using a laminator.

<Measurement of physical properties of dicing tape>
The physical properties of the dicing tapes of the dicing die-bonding films of each example and each comparative example were measured as follows.

[Elastic modulus at 120°C]
The details of the method for measuring the elastic modulus (tensile elastic modulus) of the dicing tape are as described above. Table 3 shows the measurement results of each elastic modulus at 40°C and 120°C.

[Thermal shrinkage at 120°C]
The details of the method for measuring the thermal shrinkage of the dicing tape at 120°C are as described above. Table 3 shows the measurement results of the thermal shrinkage rate.

Table 3 shows the composition and physical properties of the die-bonding sheet in each example and each comparative example.

The performance of the dicing die-bonding film produced as described above was evaluated as follows.

<Performance evaluation (separation distance (kerf) between adjacent semiconductor chips)>
(Preparation of samples for evaluation)
As a sample for evaluation, a dicing die-bonding film with a chip (die) produced using a bare wafer was prepared.
Specifically, using a laminator, a bare wafer held by a wafer processing tape (product name “UB-3083D” manufactured by Nitto Denko) was laminated to a die bond sheet of a dicing die bond film. Subsequently, the wafer processing tape was peeled off from the wafer. The bonding conditions were a bonding speed of 10 mm/sec, a temperature condition of 50 to 80° C., and a pressure condition of 0.15 MPa.
(wafer preparation)
First, a wafer processing tape (product name: UB-3083D, manufactured by Nitto Denko) was attached to the first surface of a bare wafer (12 inches in diameter, 780 μm in thickness, manufactured by Tokyo Kako Co., Ltd.) on which a modified region was to be formed. Matched. Next, using a stealth dicing apparatus (product name “DAL7360 (SDE05)”, Power: 0.25 W, Frequency: 80 kHz, manufactured by Disco), a modified region was formed inside the bare wafer. Specifically, a laser beam focused on a side near the first surface inside the wafer was irradiated from the back surface (second surface) side opposite to the first surface. Irradiation was performed along a predetermined line for dividing the bare wafer. As a result, ablation by multiphoton absorption formed a modified region for fragmentation inside the wafer (depth of 50 μm from the first surface of the wafer) so as to draw a lattice of 3 mm×7 mm per section. Thereafter, the wafer was thinned to a thickness of 30 μm by grinding from the second surface of the wafer using a back grinder (product name “DGP8760”, manufactured by Disco). As described above, a wafer held on the wafer processing tape was formed. The wafer includes compartments for dicing the wafer into multiple chips (3mm x 7mm).
(Fabrication of chip (die))
A bare wafer produced as described above was attached to a dicing die-bonding film. The bare wafer attached to the dicing die-bonding film was cut into small pieces by an expanding process. In addition, in a state in which the wafer processing tape was peeled off from the bare wafer, the expansion process was performed using a die separation device (product name "Die Separator DDS2300, manufactured by Disco"). After carrying out, normal temperature expansion was carried out.
Cool expansion was carried out as follows. Specifically, a 12-inch diameter SUS ring frame (manufactured by Disco) was attached at room temperature to the area where the frame was to be attached on the adhesive layer of the dicing die bond film attached to the bare wafer. . Subsequently, the bare wafer to which the SUS ring frame was attached was mounted on a die separating device. Then, the wafer and the die-bonding sheet were cleaved in a cool expander unit under conditions of an expansion temperature of -15°C, an expansion speed of 100mm/sec, and an expansion amount of 10mm to obtain a plurality of chips with die-bonding sheet layers.
Furthermore, normal temperature expansion was performed under the conditions of an expansion speed of 1 mm/sec and an expansion amount of 10 mm under a room temperature environment.
While maintaining the expanded state, the dicing tape in the portion surrounding the outer edge of the wafer was thermally shrunk by a heater under the conditions of a heating temperature of 250° C., a heating distance of 20 mm, and a rotation speed of 3°/sec. That is, by the heat treatment method shown in FIG. 7, the portion of the dicing tape that did not overlap with the large number of semiconductor chip groups was heat-treated, and the heat-treated portion was thermally shrunk.
After the thermal shrinkage, the gap (kerf) between the die-bonding sheet-attached chips was measured at a plurality of locations by microscopic observation. The kerf was obtained by measuring the intervals at arbitrary 10 points and arithmetically averaging the measured values. A kerf (average value) of 15 μm or more was evaluated as “good”, a case of 50 μm or more as “particularly good”, and a case of less than 15 μm as “bad”.

<Performance evaluation (suppression of kerf variations/kerf uniformity)>
After part of the dicing tape was thermally shrunk as described above, the gap (kerf) between the die-bonding sheet-attached chips was observed at a plurality of locations with a microscope. Specifically, in the portion where the interval (kerf) between chips was measured as described above, the kerf between a plurality of rectangular chips due to cutting was observed. More specifically, kerfs between chips in four chip groups adjacent in directions (directions A and B) in which two sides of each chip perpendicular to each other extend were observed. The uniformity of the kerf was evaluated depending on whether the kerf (dicing line) extending in the A direction and the B direction was straight. A case where the dicing lines were straight in both the A direction and the B direction (looked like a cross) was judged as "good". On the other hand, when the dicing line was bent in either the A direction or the B direction, it was determined as "defective".

As can be seen from the above evaluation results, the dicing die-bonding film of the example, compared to the dicing die-bonding film of the comparative example, has a sufficient kerf between semiconductor chips after the expanding process, and the variation of the kerf depending on the part. It was possible to both suppress

In the dicing die-bonding films of Examples, the elastic modulus of the dicing tape at 120° C. is 0.10 MPa or more, and the thermal shrinkage rate of the dicing tape at 120° C. is 6% or more.
By using the dicing die-bonding film of the embodiment having such a structure when manufacturing a semiconductor device, the semiconductor device can be manufactured efficiently. In the manufacture of semiconductor devices, a dicing tape is stretched and a semiconductor wafer is cut into small pieces in an expanding process. Then, after the expanding step, for example, while moving a heater or the like in one direction along the outer periphery of the large number of small semiconductor chip groups, the dicing tape around the large number of semiconductor chip groups is heated by heating. Shrink. By thermally shrinking the dicing tape around the semiconductor chip group in this way, the force of shrinking the dicing tape in the direction opposite to the stretched direction can be weakened. Since the shrinking force of the dicing tape is weakened, the space (kerf) between the adjacent semiconductor chips, which has been widened once, can be maintained. At this time, since the thermal contraction rate of the dicing tape at 120° C. is 6% or more as in the above example, loosening of the outer peripheral portion of the dicing tape after the expanding process can be sufficiently suppressed. Therefore, it is considered that the central portion of the dicing tape that overlaps the group of semiconductor chips can be prevented from shrinking and returning to its original state, so that the kerf between the semiconductor chips can be sufficiently opened.
In addition, since the elastic modulus of the dicing tape at 120 ° C. is 0.10 MPa or more as in the above example, the heat-treated portion of the dicing tape includes a portion that is first heated and has a lower temperature, and finally A heated portion having a higher temperature (for example, around 120° C.) is mixed. In this way, even if there is a temperature difference in the heat-treated portion of the dicing tape, the high-temperature portion has a relatively large elastic modulus. It is possible to suppress variations in force when the tape tries to shrink as described above. Therefore, it is considered that the variation of the kerf depending on the part in the semiconductor chip group could be suppressed.

The dicing die-bonding film of the present invention is suitably used, for example, as an auxiliary tool for manufacturing semiconductor devices (semiconductor integrated circuits).

1: dicing die bond film,
10: die bond sheet,
20: dicing tape,
21: Base material layer, 22: Adhesive layer.

Claims (8)

A base layer, a dicing tape having an adhesive layer superimposed on the base layer, and a die bond sheet superimposed on the dicing tape,
The dicing tape has an elastic modulus at 120° C. of 0.10 MPa or more,
A dicing die-bonding film, wherein the dicing tape has a heat shrinkage rate of 6% or more at 120°C. 2. The dicing die-bonding film according to claim 1, wherein the base layer contains an ethylene-vinyl acetate copolymer resin and a polypropylene resin. 3. The dicing die-bonding film according to claim 1, wherein said base material layer is composed of a plurality of layers. 4. The dicing die-bonding film according to claim 3, wherein said base material layer is composed of three or more layers. The base layer is composed of three layers in which a first base layer, a second base layer, and a third base layer are stacked,
Both the first base material layer and the third base material layer disposed on both side sides contain polypropylene resin, and the second base material layer disposed between the first base layer and the third base layer 5. The dicing die-bonding film according to claim 4, wherein the base layer contains an ethylene-vinyl acetate copolymer resin. The dicing die-bonding film according to claim 5, wherein at least one of the first base layer and the third base layer further contains an antistatic agent. The first base layer and the third base layer each independently have a thickness of 1 μm or more and 15 μm or less, and the second base layer has a thickness of 70 μm or more and 120 μm or less. The dicing die-bonding film according to 5 or 6. The surface resistivity of the surface farthest from the pressure-sensitive adhesive layer among the surfaces of the plurality of layers constituting the base material layer is 1.00×10 ⁹ [Ω/sq. ] or more 1.00×10 ¹² [Ω/sq. 8. The dicing die-bonding film according to any one of claims 3 to 7, wherein:

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