CN112778924A

CN112778924A - Dicing tape and dicing die-bonding film

Info

Publication number: CN112778924A
Application number: CN202011215663.7A
Authority: CN
Inventors: 木村雄大; 每川英利; 武田公平; 植野大树; 中浦宏
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2019-11-07
Filing date: 2020-11-04
Publication date: 2021-05-11

Abstract

The present invention relates to a dicing tape and a dicing die-bonding film. A dicing tape or the like is provided which comprises a base material layer and a pressure-sensitive adhesive layer having a higher adhesiveness than the base material layer, wherein the volume crystallinity of the base material layer calculated from the results of differential scanning calorimetry is 20J/cm³Above 120J/cm³The thickness of the base material layer is 80 μm or more.

Description

Dicing tape and dicing die-bonding film

Technical Field

The present invention relates to a dicing tape used for manufacturing, for example, a semiconductor integrated circuit, and a dicing die-bonding film provided with the dicing tape.

Background

Conventionally, dicing die-bonding films used in the manufacture of semiconductor integrated circuits have been known. Such dicing die-bonding film includes, for example, a dicing tape and a die-bonding layer laminated on the dicing tape and bonded to a wafer. The dicing tape has a base material layer and an adhesive layer in contact with the die bonding layer. Such a dicing die-bonding film is used in the manufacture of a semiconductor integrated circuit, for example, as follows.

A method for manufacturing a semiconductor integrated circuit generally includes the steps of: the method includes a pre-process of forming a circuit surface on one surface of a wafer by a highly integrated electronic circuit, and a post-process of cutting out a chip from the wafer on which the circuit surface is formed and assembling the chip.

The post-process includes, for example, the following steps: a dicing step of forming grooves in the wafer in order to cut the wafer into small chips (Die); a mounting step of attaching a surface of the wafer opposite to the circuit surface to the chip bonding layer to fix the wafer to the dicing tape; an expanding step of cutting the wafer with the groove and the chip bonding layer together to expand the interval between the chips; a picking-up step of peeling the Die bonding layer and the adhesive layer to take out the Die (Die) with the Die bonding layer bonded thereto; and a Die bonding step for bonding the Die (Die) with the Die bonding layer bonded thereto to an adherend. The semiconductor integrated circuit is manufactured through these processes.

In the above-described manufacturing method, in the expanding step, for example, the dicing tape is stretched in the radial direction at a low temperature such as below freezing point in a state where the wafer is placed on the chip bonding layer overlapped with the dicing tape, and further stretched at room temperature to expand the interval (notch) between the adjacent chips (Die). Thereafter, a portion of the cut tape, which is reduced in tension by the stretching, is thermally shrunk (heat shrink) to maintain the gap (cut). Specifically, the dicing tape at the outer side of the portion overlapping the cut chip (Die) is heat-shrunk, whereby the space (notch) can be maintained.

However, in the extension step performed under low temperature conditions, the semiconductor wafer and the die bond layer may not be cleaved together. In order to prevent such a problem, the dicing tape is desired to have a property of being able to satisfactorily cleave the semiconductor wafer through the expanding process under low temperature conditions.

On the other hand, as a conventional dicing tape, for example, a dicing tape having an initial elastic modulus at-10 ℃ of 200MPa to 380MPa and Tan δ (loss elastic modulus/storage modulus) at-10 ℃ of 0.080 to 0.3 is known (patent document 1).

According to the dicing tape described in patent document 1, when the dicing tape is used in a state in which the semiconductor wafer is bonded via the die bonding layer, the semiconductor wafer and the die bonding layer can be simultaneously cleaved by the expanding step performed under a low temperature condition.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication (JP 2015-185591)

Disclosure of Invention

Problems to be solved by the invention

However, it is said that a dicing die-bonding film or a dicing tape capable of satisfactorily cutting a semiconductor wafer in a low-temperature expanding process has not been sufficiently studied.

Accordingly, an object of the present invention is to provide a dicing tape and a dicing die-bonding film that can satisfactorily cut a semiconductor wafer in a low-temperature expansion process.

Means for solving the problems

In order to solve the above problems, the dicing tape of the present invention includes a base material layer and a pressure-sensitive adhesive layer having higher adhesiveness than the base material layer,

the volume crystallinity of the substrate layer calculated from the differential scanning calorimetry measurement result is 20J/cm³Above 120J/cm³The thickness of the base material layer is 80 μm or more.

The dicing tape having the above-described configuration can satisfactorily cut the semiconductor wafer in the low-temperature expanding step.

The above-mentioned dicing tape is preferably: the base material layer has an endothermic peak whose peak temperature is 100 ℃ or higher, as measured by differential scanning calorimetry. This has the advantage that the crystallinity of the base material layer becomes higher, and the mechanical energy due to the expansion can be transmitted more efficiently to the base material layer.

The dicing die-bonding film of the present invention includes the dicing tape and the die-bonding layer attached to the dicing tape.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the dicing tape and the dicing die-bonding film of the present invention, the semiconductor wafer can be favorably diced in the low-temperature expanding step.

Drawings

Fig. 1 is a sectional view of the dicing die-bonding film according to the present embodiment cut in the thickness direction.

Fig. 2A is a sectional view schematically showing a case of half-cut processing in the manufacturing method of the semiconductor integrated circuit.

Fig. 2B is a sectional view schematically showing a case of half-cut processing in the manufacturing method of the semiconductor integrated circuit.

Fig. 2C is a sectional view schematically showing a case of half-cut processing in the manufacturing method of the semiconductor integrated circuit.

Fig. 2D is a sectional view schematically showing a case of half-cut processing in the manufacturing method of the semiconductor integrated circuit.

Fig. 3A is a sectional view schematically showing a case of a mounting process in a manufacturing method of a semiconductor integrated circuit.

Fig. 3B is a sectional view schematically showing a case of a mounting process in the manufacturing method of the semiconductor integrated circuit.

Fig. 4A is a cross-sectional view schematically showing a case of an expanding process at a low temperature in a manufacturing method of a semiconductor integrated circuit.

Fig. 4B is a sectional view schematically showing a case of an expanding process at a low temperature in the manufacturing method of the semiconductor integrated circuit.

Fig. 4C is a sectional view schematically showing a case of an expanding process at a low temperature in the manufacturing method of the semiconductor integrated circuit.

Fig. 5A is a cross-sectional view schematically showing a case of an expansion process at normal temperature in the method of manufacturing a semiconductor integrated circuit.

Fig. 5B is a sectional view schematically showing a case of an expansion process at normal temperature in the method of manufacturing a semiconductor integrated circuit.

Fig. 6 is a sectional view schematically showing a case of a pickup process in the manufacturing method of the semiconductor integrated circuit.

Fig. 7A is a first spectrum showing an example of differential scanning calorimetry (example 1).

Fig. 7B is a second spectrum showing an example of differential scanning calorimetry (example 1).

Fig. 8A is a first spectrum showing an example of differential scanning calorimetry (comparative example 1).

Fig. 8B is a second spectrum showing an example of differential scanning calorimetry (comparative example 1).

Description of the reference numerals

1: cutting the chip bonding film,

10: a chip bonding layer,

20: a cutting belt,

21: a base material layer,

22: an adhesive layer.

Detailed Description

Hereinafter, one embodiment of the dicing die-bonding film and the dicing tape according to the present invention will be described with reference to the drawings.

The dicing die-bonding film 1 of the present embodiment includes a dicing tape 20 and a die-bonding layer 10 laminated on an adhesive layer 22 of the dicing tape 20 and bonded to a semiconductor wafer.

The dicing tape 20 of the present embodiment is generally a long sheet, and is stored in a wound state until use. The dicing die-bonding film 1 of the present embodiment is used by being bonded to an annular frame having an inner diameter one turn larger than that of a silicon wafer to be subjected to dicing, and then being diced.

The dicing tape 20 of the present embodiment includes a base material layer 21 and a pressure-sensitive adhesive layer 22 stacked on the base material layer 21.

In the dicing tape 20 of the present embodiment, the volume crystallinity of the base material layer 21 calculated from the differential scanning calorimetry measurement result is 20J/cm³Above 120J/cm³The thickness of the base material layer 21 is 80 μm or more.

The dicing tape 20 of the present embodiment has the above-described configuration, and therefore, can favorably cut the semiconductor wafer in the low-temperature expanding step.

The volume crystallinity is a value obtained by performing differential scanning calorimetry (DSC measurement) on the base material layer 21 and based on the measurement result.

Specifically, differential scanning calorimetry (DSC measurement) for the base material layer 21 was performed under the following measurement conditions. From the spectrum obtained by 1 measurement, the volume crystallinity calculated as follows was obtained.

Specifically, about 10mg of a measurement sample was weighed using a commercially available DSC measuring apparatus, and the temperature was raised from room temperature (about 20 ℃) to 200 ℃ at a temperature rise rate of 5 ℃/min, and the measurement was performed under a nitrogen atmosphere. The measurement sample is prepared by cutting the substrate layer 21 in the thickness direction.

The endothermic amount was calculated from the area of an endothermic peak appearing in a spectrum obtained by differential scanning calorimetry (DSC measurement). The area of the endothermic peak is calculated by obtaining an area surrounded by a base line connecting a point on the low temperature side and a point on the high temperature side, which do not change in heat, in the peak and a curve describing the endothermic peak. The endothermic amount is calculated based on the endothermic peak accompanying the melting. The calculated heat absorption amount is converted into a value per unit volume. When the base material layer 21 is formed of a plurality of layers of different materials, a plurality of endothermic peaks may appear in the measurement spectrum. When the amount of heat absorption is calculated, the amount of heat absorption is calculated from the area of each heat absorption peak due to each layer, and the value obtained by dividing the total amount of heat absorption by the total volume of the base material layer 21 is used as the bulk crystallinity of the base material layer 21.

The area of the endothermic peak appearing in the measurement spectrum was calculated by the analysis software attached to the DSC measurement apparatus.

In addition, although an exothermic peak and a curve based on the glass transition temperature may appear in the measurement spectrum, they are not considered as endothermic peaks.

The respective temperatures at the peak start point (hereinafter, also simply referred to as point a), the peak top point (hereinafter, also simply referred to as point C), and the peak end point (hereinafter, also simply referred to as point B) of the endothermic peak appearing in the measurement spectrum are measured by analysis software attached to the DSC measurement apparatus.

Most desirably: the area of the endothermic peak, the peak start point, the peak apex, and the peak end point were determined by specific analysis software described in the following examples, based on the measurement results obtained by using a specific DSC measurement device described in the following examples.

If the above-mentioned volume crystallinity is less than 20J/cm³The crystallinity of the base material layer 21 is insufficient, and hence the cuttability may be poor. On the other hand, if the above-mentioned volume crystallinity is more than 120J/cm³Since the crystallinity of the base material layer 21 is too high, the base material layer 21 may be broken when expanded.

The above-mentioned volume crystallinity is preferably 25J/cm³Above, more preferably 26J/cm³More preferably 30J/cm or more³The above. This has the advantage of exhibiting more favorable cuttability in the low-temperature expansion step.

The above-mentioned volume crystallinity is preferably 100J/cm³Less than, more preferably 90J/cm³Hereinafter, more preferably 82J/cm³The following. This has the advantage that cracking of the base material layer 21 during expansion is further suppressed.

For example, the bulk crystallinity can be further increased by forming the base layer 21 from a resin material having a higher crystallinity or by performing a slow cooling treatment or a stretching treatment when the base layer 21 is formed. On the other hand, the bulk crystallinity can be further reduced by forming the base material layer 21 from a resin material having a lower crystallinity, or by not performing a rapid cooling treatment or a stretching treatment when the base material layer 21 is produced, for example.

The spectrum measured by Differential Scanning Calorimetry (DSC) of the base material layer 21 preferably has an endothermic peak having a peak (point C) in the range of 100 ℃ or higher and 140 ℃ or lower. The endothermic peak is, for example, an endothermic peak occurring along with melting of the resin.

By making the peak of the endothermic peak (point C) at 100 ℃ or higher, there is an advantage that the incision can be maintained by rapidly curing after completion of thermal shrinkage. Further, there is an advantage that a better cuttability is exhibited. The peak of the endothermic peak (point C) is more preferably present at 105 ℃ or higher.

The presence of the peak of the endothermic peak (point C) at 140 ℃ or lower has an advantage that sufficient thermal shrinkage can be caused during thermal shrinkage. The peak of the endothermic peak (point C) is more preferably present at 135 ℃ or lower.

When a plurality of endothermic peaks are present in the range of 100 ℃ to 140 ℃, it is preferable that at least 1 endothermic peak among them satisfies the above condition (peak top). Likewise, it is preferable that at least 1 endothermic peak satisfies the following conditions (peak start point, end point, etc.).

For example, the peak (C point) of the endothermic peak can be shifted to a higher temperature by forming the base material layer 21 from a resin material having a higher melting point, forming the base material layer 21 of a laminated structure using a layer of a resin material having a higher melting point, or blending (blending) a resin material having a higher melting point into the base material layer 21. On the other hand, for example, by forming the base layer 21 from a resin material having a lower melting point, forming the base layer 21 of a laminated structure using a layer of a resin material having a lower melting point, or blending (blending) a resin material having a lower melting point into the base layer 21, the temperature of the top (C point) of the endothermic peak can be shifted to a lower temperature.

The temperature difference between the starting point (point A) and the peak (point C) of the endothermic peak is preferably 40 ℃ or less, more preferably 35 ℃ or less.

By setting the temperature difference to 40 ℃ or less, the melting of the base material layer 21 can be completed with a smaller (narrow) temperature difference. Thus, curing and softening of the base material layer 21 can be achieved with a smaller temperature difference. Therefore, the base material layer 21 is thermally shrunk (heat shrink) after expansion and is rapidly cured after thermal shrinkage is completed, so that the interval (notch) between the adjacent chips (Die) can be efficiently maintained.

The temperature difference between the starting point (point A) and the peak (point C) of the endothermic peak may be 20 ℃ or more.

For example, by further increasing the molecular weight dispersion of the resin (polymer) contained in the base material layer 21, the temperature difference between the peak start point (point a) and the peak (point C) in the endothermic peak can be further increased.

For example, by further reducing the molecular weight dispersion of the resin (polymer) contained in the base material layer 21, the temperature difference between the peak start point (point a) and the peak (point C) in the endothermic peak can be further reduced.

In the dicing tape, the temperature difference between the peak start point (point a) and the peak end point (point B) in the endothermic peak of the substrate layer 21 is preferably 60 ℃ or less, more preferably 50 ℃ or less. By setting the temperature difference to 60 ℃ or less, the temperature difference from the start of melting to the end of melting of the base material layer 21 becomes smaller, and therefore, solidification and softening of the base material layer 21 can be achieved with a smaller temperature difference. Therefore, there is an advantage that the heat shrinkage after expansion can be efficiently performed.

The temperature difference may be 30 ℃ or more.

For example, by further reducing the molecular weight dispersion of the resin (polymer) contained in the base material layer 21, the temperature difference between the peak start point (point a) and the peak end point (point B) can be further reduced. On the other hand, for example, by further increasing the molecular weight dispersion degree of the resin (polymer) included in the base material layer 21, the temperature difference between the peak start point (point a) and the peak end point (point B) can be further increased.

In the dicing tape, the temperature of the peak starting point (point a) in the endothermic peak of the substrate layer 21 is preferably 70 ℃ or higher, and more preferably 80 ℃ or higher. The peak start point (point a) is an index of the temperature at which the base material layer 21 finishes curing, and by setting the temperature at the peak start point to 70 ℃ or higher, the base material layer 21 that has been temporarily softened by the heater starts cooling and finishes curing at a higher temperature. If the temperature is lower than 70 ℃, the curing of the base material layer 21 is completed, and therefore the heat shrinkage after expansion can be sufficiently performed. Therefore, the incision can be efficiently maintained after the expansion.

The temperature at the starting point of the peak (point A) may be 110 ℃ or lower, or may be 100 ℃ or lower.

For example, the temperature at the peak start point (point a) can be shifted to a higher temperature by forming the base material layer 21 from a resin material having a higher melting point, forming the base material layer 21 of a laminated structure using a layer of a resin material having a higher melting point, or blending (blending) a resin material having a higher melting point into the base material layer 21. On the other hand, for example, by forming the base material layer 21 from a resin material having a lower melting point, or by forming the base material layer 21 of a laminated structure using a layer of a resin material having a lower melting point, or by blending (blending) a resin material having a lower melting point into the base material layer 21, the temperature of the peak starting point (point a) can be shifted to a lower temperature.

In the dicing tape, the temperature of the peak end point (point B) in the endothermic peak of the base material layer 21 is preferably 150 ℃ or lower, and more preferably 140 ℃ or lower. The peak end point (B point) is an index of the temperature at which the softening of the base material layer 21 is ended, and by setting the temperature of the peak end point to 150 ℃ or lower, the base material layer 21 can be sufficiently softened even if the heating temperature of the heater is slightly lower than 150 ℃. Therefore, the thermal shrinkage can be efficiently performed even at a slightly low heating temperature for softening, and therefore, the incision can be efficiently maintained well after the expansion.

The temperature at the peak ending point (point B) may be 110 ℃ or higher, or may be 120 ℃ or higher.

For example, the temperature of the peak end point (point B) can be shifted to a lower temperature by forming the base material layer 21 from a resin material having a lower melting point, forming the base material layer 21 of a laminated structure using a layer of a resin material having a lower melting point, or blending (blending) a resin material having a lower melting point into the base material layer 21. On the other hand, for example, by forming the base layer 21 from a resin material having a higher melting point, forming the base layer 21 of a laminated structure using a layer of a resin material having a higher melting point, or blending (blending) a resin material having a higher melting point into the base layer 21, the temperature of the peak end point (B point) can be shifted to a higher temperature.

The substrate layer 21 may have a single-layer structure or a laminated structure.

Each layer of the base layer 21 is, for example, a fibrous sheet such as a metal foil, paper, or cloth, a rubber sheet, or a resin film.

Examples of the fiber sheet constituting the base material layer 21 include paper, woven fabric, and nonwoven fabric.

Examples of the material of the resin film include polyolefins such as Polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymers; ethylene copolymers such as ethylene-vinyl acetate copolymers (EVA), ionomer resins, ethylene- (meth) acrylic acid copolymers, and ethylene- (meth) acrylate (random, alternating) copolymers; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT); a polyacrylate; polyvinyl chloride (PVC); a polyurethane; a polycarbonate; polyphenylene Sulfide (PPS); polyamides such as aliphatic polyamides and wholly aromatic polyamides (aramid fibers); polyetheretherketone (PEEK); a polyimide; a polyetherimide; polyvinylidene chloride; ABS (acrylonitrile-butadiene-styrene copolymer); cellulose or a cellulose derivative; a silicone-containing polymer; fluorine-containing polymers, and the like. These can be used alone in 1 or a combination of 2 or more.

The base layer 21 is preferably made of a polymer material such as a resin film.

When the base layer 21 has a resin film, the resin film may be subjected to a stretching treatment or the like to control the deformability such as elongation.

The surface of the base material layer 21 may be subjected to a surface treatment in order to improve adhesion to the pressure-sensitive adhesive layer 22. As the surface treatment, for example, oxidation treatment based on a chemical method or a physical method such as chromic acid treatment, ozone exposure, flame exposure, high-voltage electric shock exposure, ionizing radiation treatment, or the like can be employed. Further, coating treatment with a coating agent such as an anchor coating agent, a primer, or an adhesive may be performed.

The base material layer 21 is preferably composed of a plurality of layers, more preferably at least 3 layers, and further preferably 3 layers.

By providing the base material layer 21 with a laminated structure of a plurality of layers (for example, a 3-layer structure), a layer having a higher elastic modulus and a layer having a lower elastic modulus can be laminated, and therefore, there is an advantage that the elastic modulus of the base material layer 21 can be controlled relatively easily. For example, in the case of a base material layer having only a layer with a high elastic modulus, chip lifting and substrate cracking may occur in the spreading step. Further, for example, in the case of a base material layer having only a layer with a low elastic modulus, a sufficient stress for cleaving by spreading may not be transmitted to the base material layer.

The base layer 21 having a 3-layer structure preferably includes two non-elastic layers (X, X) made of a non-elastic material and an elastic layer (Y) (X layer/Y layer/X layer) made of an elastic material and disposed between the two non-elastic layers.

The elastic layer has an elastic modulus of 200MPa or less at room temperature. The elastomer layer is generally formed of a polymer material exhibiting rubber elasticity at room temperature (23 ℃). On the other hand, the non-elastomeric layer is a layer having an elastic modulus at room temperature of more than 200 MPa.

Each layer of the elastomer having such a 3-layer laminated structure is generally formed of a resin. The elastomer having a 3-layer laminated structure is produced by, for example, coextrusion molding, and 3 layers are integrated.

In the base material layer 21 having a 3-layer structure, the ratio of the thickness of the inner layer to the thickness of 1 outer layer (Y thickness/X thickness) is preferably 5 or more and 15 or less.

The non-elastic body layer disposed on the outer side has a melting point of, for example, 100 ℃ to 140 ℃. The non-elastic body layer preferably has a molecular weight distribution dispersity (mass average molecular weight/number average molecular weight) of 3 or less when GPC measurement is performed on the constituent resin.

The non-elastomeric layer (X) may comprise Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), polypropylene, etc. Examples of the polypropylene include homopolymers (homo-polypropylene), copolymers such as random polypropylene and block polypropylene. The polypropylene may be a metallocene polypropylene synthesized using a metallocene catalyst. The non-elastomeric layer (X) preferably comprises metallocene polypropylene.

On the other hand, the elastomer layer (Y) preferably contains an ethylene-vinyl acetate copolymer (EVA) or an α -olefin-based thermoplastic elastomer, and more preferably contains an ethylene-vinyl acetate copolymer (EVA). Examples of the α -olefin-based thermoplastic elastomer include homopolymers of α -olefins and copolymers of two or more kinds of α -olefins.

The ethylene-vinyl acetate copolymer resin (EVA) may contain 5 mass% or more and 35 mass% or less of structural units of vinyl acetate.

The thickness (total thickness) of the base material layer 21 is 80 μm or more. The thickness may exceed 100 μm. The thickness may be 150 μm or less. The value is an average of randomly selected measured values of at least 3. Hereinafter, the average value of the thickness of the pressure-sensitive adhesive layer 22 is also used in the same manner.

If the thickness of the base material layer 21 is less than 80 μm, stress may not be uniformly applied to the entire base material layer 21, and good cuttability in the low-temperature expansion step may not be exhibited.

The back surface side of the base material layer 21 (the side not overlapping the pressure-sensitive adhesive layer 22) may be subjected to release treatment with a release agent (release agent) such as a silicone resin or a fluorine resin, for example, in order to impart releasability.

The base layer 21 is preferably a light-transmitting (ultraviolet-transmitting) resin film or the like, in view of being able to impart active energy rays such as ultraviolet rays to the pressure-sensitive adhesive layer 22 from the back side.

The dicing tape 20 of the present embodiment may be provided with a release sheet covering one surface of the pressure-sensitive adhesive layer 22 (the surface of the pressure-sensitive adhesive layer 22 that does not overlap with the base material layer 21) in a state before use. When the die-bonding layer 10 having an area smaller than that of the adhesive layer 22 is disposed so as to be accommodated in the adhesive layer 22, the release sheet is disposed so as to cover both the adhesive layer 22 and the die-bonding layer 10. The release sheet is used to protect the adhesive layer 22, and is peeled off before the die-bonding layer 10 is attached to the adhesive layer 22.

As the release sheet, for example, a plastic film or paper surface-treated with a release agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide can be used.

As the release sheet, for example, a film made of a fluorine-based polymer such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer; films made of polyolefins such as polyethylene and polypropylene; and films made of polyesters such as polyethylene terephthalate (PET).

As the release sheet, for example, a plastic film or paper coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent can be used.

Note that the release sheet may be used as a support material for supporting the adhesive layer 22. In particular, when the pressure-sensitive adhesive layer 22 is superimposed on the base layer 21, a release sheet can be suitably used. Specifically, the pressure-sensitive adhesive layer 22 can be stacked on the base material layer 21 by stacking the pressure-sensitive adhesive layer 22 on the base material layer 21 in a state where the release sheet and the pressure-sensitive adhesive layer 22 are stacked, and peeling (transferring) the release sheet after stacking.

In the present embodiment, the adhesive layer 22 contains, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator.

The adhesive layer 22 preferably has a thickness of 5 μm or more and 40 μm or less. The shape and size of the adhesive layer 22 are generally the same as those of the base material layer 21.

In the dicing tape 20 of the present embodiment, the ratio of the thickness of the pressure-sensitive adhesive layer 22 to the total thickness of the dicing tape 20 may be 5% to 30%.

The acrylic polymer has at least a structural unit of an alkyl (meth) acrylate, a structural unit of a hydroxyl group-containing (meth) acrylate, and a structural unit of a polymerizable group-containing (meth) acrylate in the molecule. The structural unit is a unit constituting the main chain of the acrylic polymer. Each side chain in the acrylic polymer is contained in each structural unit constituting the main chain.

In the present specification, the expression "(meth) acrylate" means at least one of methacrylate and acrylate. Likewise, the expression "(meth) acrylic acid" means at least one of methacrylic acid and acrylic acid.

In the acrylic polymer contained in the pressure-sensitive adhesive layer 22, the above-mentioned structural unit can pass through¹H-NMR、¹³NMR analysis such as C-NMR, thermal decomposition GC/MS analysis, infrared spectroscopy, and the like. The molar ratio of the above-mentioned structural unit in the acrylic polymer is usually calculated from the amount of the acrylic polymer blended (charged amount) at the time of polymerization.

The structural unit of the above-mentioned alkyl (meth) acrylate is derived from an alkyl (meth) acrylate monomer. In other words, the molecular structure of the alkyl (meth) acrylate monomer after polymerization is the structural unit of the alkyl (meth) acrylate. The expression "alkyl group" means the number of carbon atoms of a hydrocarbon moiety which forms an ester bond with (meth) acrylic acid.

The hydrocarbon moiety of the alkyl moiety in the structural unit of the alkyl (meth) acrylate may be a saturated hydrocarbon or an unsaturated hydrocarbon.

The alkyl moiety preferably does not contain a polar group containing oxygen (O), nitrogen (N), or the like. This can suppress an extreme increase in polarity of the alkyl polymer. Therefore, the adhesive layer 22 can be suppressed from having excessive affinity with respect to the chip bonding layer 10. Thus, the dicing tape 20 can be more favorably peeled off from the chip bonding layer 10. The number of carbon atoms of the alkyl moiety may be 6 or more and 10 or less.

Examples of the structural unit of the alkyl (meth) acrylate include structural units such as hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, and decyl (meth) acrylate.

The acrylic polymer has a structural unit of a hydroxyl group-containing (meth) acrylate, and the hydroxyl group of the structural unit is easily reacted with an isocyanate group.

By allowing an acrylic polymer having a structural unit of a hydroxyl group-containing (meth) acrylate and an isocyanate compound to coexist in advance in the pressure-sensitive adhesive layer 22, the pressure-sensitive adhesive layer 22 can be appropriately cured. Therefore, the acrylic polymer can be sufficiently gelled. Thus, the adhesive layer 22 can exert adhesive properties while maintaining the shape.

The structural unit of the hydroxyl group-containing (meth) acrylate is preferably a structural unit of a hydroxyl group-containing C2-C4 alkyl (meth) acrylate. The expression "C2-C4 alkyl" denotes the number of carbon atoms of the hydrocarbon moiety which forms an ester bond with (meth) acrylic acid. In other words, the hydroxyl group-containing alkyl (meth) acrylate monomers of C2 to C4 represent monomers in which (meth) acrylic acid forms an ester bond with an alcohol having 2 to 4 carbon atoms (usually a diol).

The hydrocarbon moiety of the C2-C4 alkyl group is typically a saturated hydrocarbon. For example, the hydrocarbon moiety of the C2-C4 alkyl group is a straight-chain saturated hydrocarbon or a branched-chain saturated hydrocarbon. The hydrocarbon moiety of the C2-C4 alkyl group preferably does not contain a polar group containing oxygen (O), nitrogen (N), or the like.

Examples of the structural unit of the hydroxyl group-containing alkyl (meth) acrylates having C2 to C4 include structural units of hydroxybutyl (meth) acrylate such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxy-n-butyl (meth) acrylate, and hydroxyisobutyl (meth) acrylate. In the structural unit of hydroxybutyl (meth) acrylate, a hydroxyl group (-OH group) may be bonded to a carbon (C) at the end of the hydrocarbon moiety or to a carbon (C) other than the end of the hydrocarbon moiety.

The acrylic polymer contains a structural unit of a polymerizable group-containing (meth) acrylate having a polymerizable unsaturated double bond in a side chain.

By including the structural unit of the polymerizable group-containing (meth) acrylate in the acrylic polymer, the pressure-sensitive adhesive layer 22 can be cured by irradiation with active energy rays (ultraviolet rays or the like) before the pickup step. Specifically, by irradiation with active energy rays such as ultraviolet rays, radicals are generated from the photopolymerization initiator, and the acrylic polymers can be crosslinked by the action of the radicals. This can reduce the adhesive force of the pressure-sensitive adhesive layer 22 before irradiation by irradiation. Further, the chip bonding layer 10 can be favorably peeled from the adhesive layer 22.

As the active energy ray, ultraviolet rays, radiation rays, and electron rays can be used.

Specifically, the structural unit of the polymerizable group-containing (meth) acrylate may have a molecular structure in which a urethane bond is formed between a hydroxyl group in the structural unit of the hydroxyl group-containing (meth) acrylate and an isocyanate group in the isocyanate group-containing (meth) acrylate monomer.

The structural unit of the polymerizable group-containing (meth) acrylate having a polymerizable group can be prepared after polymerization of the acrylic polymer. For example, the structural unit of the polymerizable group-containing (meth) acrylate may be obtained by copolymerizing an alkyl (meth) acrylate monomer and a hydroxyl group-containing (meth) acrylate monomer, and then subjecting hydroxyl groups in a part of the structural units of the hydroxyl group-containing (meth) acrylate and isocyanate groups in the isocyanate group-containing polymerizable monomer to a urethanization reaction.

The isocyanate group-containing (meth) acrylate monomer preferably has 1 isocyanate group and 1 (meth) acryloyl group in the molecule. Examples of the monomer include 2- (meth) acryloyloxyethyl isocyanate ((2-isocyanatoethyl (meth) acrylate)).

The adhesive layer 22 of the dicing tape 20 in this embodiment further contains an isocyanate compound. A part of the isocyanate compound may be in a state after the reaction by a urethanization reaction or the like.

The isocyanate compound has a plurality of isocyanate groups in a molecule. By having a plurality of isocyanate groups in a molecule, the acrylic polymer in the pressure-sensitive adhesive layer 22 can be cross-linked. Specifically, the crosslinking reaction can be performed by the isocyanate compound by reacting one isocyanate group of the isocyanate compound with a hydroxyl group of the acrylic polymer and reacting the other isocyanate group with a hydroxyl group of the other acrylic polymer.

Examples of the isocyanate compound include diisocyanates such as aliphatic diisocyanate, alicyclic diisocyanate, and araliphatic diisocyanate.

Further, as the isocyanate compound, for example, polymeric polyisocyanates such as dimer and trimer of diisocyanate; polymethylene polyphenylene polyisocyanates.

Examples of the isocyanate compound include polyisocyanates obtained by reacting an excess of the isocyanate compound with an active hydrogen-containing compound. Examples of the active hydrogen-containing compound include an active hydrogen-containing low-molecular weight compound and an active hydrogen-containing high-molecular weight compound.

As the isocyanate compound, allophanate polyisocyanate, biuret polyisocyanate, or the like can be used.

The isocyanate compounds can be used alone in 1 or two or more.

As the isocyanate compound, a reaction product of an aromatic diisocyanate and a low molecular weight compound containing active hydrogen is preferable. The reaction speed of the isocyanate group in the reaction product of the aromatic diisocyanate is slow, and therefore, excessive curing of the adhesive layer 22 containing the reaction product is suppressed. The isocyanate compound is preferably an isocyanate compound having 3 or more isocyanate groups in the molecule.

The polymerization initiator contained in the adhesive layer 22 is a compound capable of initiating a polymerization reaction by applied thermal energy or light energy. By including the polymerization initiator in the pressure-sensitive adhesive layer 22, a crosslinking reaction between acrylic polymers can be performed when thermal energy or optical energy is applied to the pressure-sensitive adhesive layer 22. Specifically, the pressure-sensitive adhesive layer 22 can be cured by initiating a polymerization reaction between polymerizable groups in an acrylic polymer having a structural unit of a polymerizable group-containing (meth) acrylate. This can reduce the adhesive strength of the adhesive layer 22, and the die-bonding layer 10 can be easily peeled from the cured adhesive layer 22 in the pickup step.

As the polymerization initiator, for example, a photopolymerization initiator, a thermal polymerization initiator, or the like can be used. As the polymerization initiator, a general commercially available product can be used.

The adhesive layer 22 may further contain other components in addition to the above components. Examples of the other components include a tackifier, a plasticizer, a filler, an antioxidant, an ultraviolet absorber, a light stabilizer, a heat stabilizer, an antistatic agent, a surfactant, and a light releasing agent. The kind and amount of the other ingredients may be appropriately selected depending on the purpose.

Next, the dicing die-bonding film 1 of the present embodiment will be described in detail.

The dicing die-bonding film 1 of the present embodiment includes the dicing tape 20 and the die-bonding layer 10 laminated on the adhesive layer 22 of the dicing tape 20. The die bonding layer 10 is bonded to a semiconductor wafer in the manufacture of a semiconductor integrated circuit.

The chip bonding layer 10 may include at least one of a thermosetting resin and a thermoplastic resin. The chip bonding layer 10 preferably contains a thermosetting resin and a thermoplastic resin.

Examples of the thermosetting resin include epoxy resins, phenol resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. The thermosetting resin may be used alone in 1 kind or in two or more kinds. The thermosetting resin is preferably an epoxy resin because the thermosetting resin contains less ionic impurities and the like that may cause corrosion of the semiconductor chip to be die-bonded. As the curing agent for the epoxy resin, a phenol resin is preferable.

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 novolac type, o-cresol novolac type, trishydroxyphenylmethane type, tetrahydroxyphenylethane type, hydantoin type, triglycidyl isocyanurate type, and glycidylamine type epoxy resins.

The phenolic resin can function as a curing agent for epoxy resins. Examples of the phenol resin include novolak phenol resins, resol phenol resins, and polyoxystyrenes such as polyoxystyrenes.

Examples of the novolak type phenol resin include a phenol novolak resin, a phenol aralkyl resin, a cresol novolak resin, a tert-butylphenol novolak resin, a nonylphenol novolak resin, and the like.

The phenolic resin may be used alone in 1 kind or in two or more kinds.

In the chip bonding layer 10, the hydroxyl group of the phenol resin is preferably 0.5 equivalent or more and 2.0 equivalents or less, and more preferably 0.7 equivalent or more and 1.5 equivalents or less, to 1 equivalent of the epoxy group of the epoxy resin. This enables the epoxy resin and the phenol resin to be sufficiently cured.

When the chip bonding layer 10 contains a thermosetting resin, the content ratio of the thermosetting resin in the chip bonding layer 10 is preferably 5% by mass or more and 60% by mass or less, and more preferably 10% by mass or more and 50% by mass or less, with respect to the total mass of the chip bonding layer 10. This enables the chip bonding layer 10 to appropriately exhibit a function as a thermosetting adhesive.

Examples of the thermoplastic resin that can be contained in the chip bonding layer 10 include polyamide resins such as natural rubber, butyl rubber, isoprene rubber, chloroprene rubber, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid copolymer, an ethylene-acrylic ester copolymer, a polybutadiene resin, a polycarbonate resin, a thermoplastic polyimide resin, 6-nylon, and 6, 6-nylon (trade name); saturated polyester resins such as phenoxy resins, acrylic resins, PET, PBT and the like; polyamide-imide resins, fluorine resins, and the like.

The thermoplastic resin is preferably an acrylic resin in that the adhesiveness of the chip bonding layer 10 can be further ensured because of the low content of ionic impurities and the high heat resistance.

The thermoplastic resin may be used alone in 1 kind or in two or more kinds.

The acrylic resin is preferably a polymer having the largest number of structural units of alkyl (meth) acrylate among the structural units in the molecule in terms of mass ratio. Examples of the alkyl (meth) acrylate include C2 to C4 alkyl (meth) acrylates.

The acrylic resin may contain a structural unit derived from another monomer component copolymerizable with the alkyl (meth) acrylate monomer.

Examples of the other monomer components include carboxyl group-containing monomers, acid anhydride monomers, hydroxyl group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, functional group-containing monomers such as acrylamide and acrylonitrile, and other various polyfunctional monomers.

From the viewpoint of enabling the chip bonding layer 10 to exhibit higher cohesive force, the acrylic resin is preferably a copolymer of an alkyl (meth) acrylate (particularly, an alkyl (meth) acrylate having 4 or less carbon atoms in the alkyl moiety) and a carboxyl group-containing monomer and a monomer containing a nitrogen atom and a polyfunctional monomer (particularly, a polyglycidyl-based polyfunctional monomer), and more preferably a copolymer of ethyl acrylate and butyl acrylate and acrylic acid, acrylonitrile, and polyglycidyl (meth) acrylate.

The glass transition temperature (Tg) of the acrylic resin is preferably-50 ℃ or higher and 50 ℃ or lower, and more preferably 10 ℃ or higher and 30 ℃ or lower, in order to easily set the elasticity and viscosity of the chip bonding layer 10 within desired ranges.

When the chip bonding layer 10 contains a thermosetting resin and a thermoplastic resin, the content ratio of the thermoplastic resin in the chip bonding layer 10 is preferably 30 mass% or more and 70 mass% or less, more preferably 40 mass% or more and 60 mass% or less, and further preferably 45 mass% or more and 55 mass% or less, with respect to the total mass of organic components other than the filler (for example, the thermosetting resin, the thermoplastic resin, the curing catalyst, and the like, the silane coupling agent, and the dye). The elasticity and viscosity of the chip bonding layer 10 can be adjusted by changing the content ratio of the thermosetting resin.

When the thermoplastic resin of the chip bonding layer 10 has a thermosetting functional group, an acrylic resin containing a thermosetting functional group can be used as the thermoplastic resin, for example. The thermosetting functional group-containing acrylic resin preferably contains a structural unit derived from an alkyl (meth) acrylate in the largest mass ratio in the molecule. Examples of the alkyl (meth) acrylate include the alkyl (meth) acrylates exemplified above.

On the other hand, examples of the thermosetting functional group in the thermosetting functional group-containing acrylic resin include glycidyl group, carboxyl group, hydroxyl group, isocyanate group and the like.

The chip bonding layer 10 preferably contains an acrylic resin containing a thermosetting functional group and a curing agent. When the thermosetting functional group in the thermosetting functional group-containing acrylic resin is a glycidyl group, a compound having a plurality of phenolic structures is preferably used as the curing agent. As the curing agent, for example, various phenolic resins as described above can be used.

The chip bonding layer 10 preferably contains a filler. By changing the amount of the filler in the chip bonding layer 10, the elasticity and viscosity of the chip bonding layer 10 can be more easily adjusted. Further, physical properties such as electrical conductivity, thermal conductivity, and elastic modulus of the chip bonding layer 10 can be adjusted.

Examples of the filler include inorganic fillers and organic fillers. As the filler, an inorganic filler is preferable.

Examples of the inorganic filler include fillers such as silica including aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum nitride, boron nitride, crystalline silica, and amorphous silica. Further, as the material of the inorganic filler, simple metal substances such as aluminum, gold, silver, copper, nickel, and the like; alloys, and the like. Can be fillers such as aluminum borate whisker, amorphous carbon black, graphite and the like. The filler may be in the form of a sphere, needle, scale, or other various shapes. As the filler, only 1 kind or two or more kinds of the above may be used.

The average particle diameter of the filler is preferably 0.005 μm or more and 10 μm or less, more preferably 0.005 μm or more and 1 μm or less. By setting the average particle size to 0.005 μm or more, wettability and adhesiveness to an adherend such as a semiconductor wafer are further improved. By setting the average particle diameter to 10 μm or less, the properties of the added filler can be more sufficiently exhibited, and the heat resistance of the chip bonding layer 10 can be further exhibited. The average particle diameter of the filler can be determined, for example, by using a photometric particle size distribution meter (e.g., product name "LA-910", manufactured by horiba Seisakusho).

When the chip bonding layer 10 contains a filler, the content ratio of the filler is preferably 30% by mass or more and 70% by mass or less, more preferably 40% by mass or more and 60% by mass or less, and still more preferably 42% by mass or more and 55% by mass or less, with respect to the total mass of the chip bonding layer 10.

The chip bonding layer 10 may contain other components as necessary. Examples of the other components include a curing catalyst, a flame retardant, a silane coupling agent, an ion scavenger, and a dye.

Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins.

Examples of the silane coupling agent include β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ -glycidoxypropyltrimethoxysilane, and γ -glycidoxypropylmethyldiethoxysilane.

Examples of the ion scavenger include hydrotalcites, bismuth hydroxide, and benzotriazole.

As the other additives, only 1 kind or two or more kinds may be used.

From the viewpoint of easy adjustment of elasticity and viscosity, the chip bonding layer 10 preferably contains a thermoplastic resin (particularly an acrylic resin), a thermosetting resin, and a filler.

The thickness of the chip bonding layer 10 is not particularly limited, and is, for example, 1 μm or more and 200 μm or less. The thickness may be 3 μm or more and 150 μm or less, or 5 μm or more and 100 μm or less. When the die bonding layer 10 is a laminate, the thickness is the total thickness of the laminate.

The glass transition temperature (Tg) of the chip bonding layer 10 is preferably 0 ℃ or higher, and more preferably 10 ℃ or higher. By setting the glass transition temperature to 0 ℃ or higher, the chip bonding layer 10 can be easily cleaved by low-temperature expansion. The upper limit of the glass transition temperature of the chip bonding layer 10 is, for example, 100 ℃.

The chip bonding layer 10 may have a single-layer structure as shown in fig. 1, for example. In the present specification, a single layer means a layer having only the same composition. A single layer is also a form in which a plurality of layers made of the same composition are stacked.

On the other hand, the chip bonding layer 10 may have a multilayer structure in which layers each formed of two or more different compositions are stacked, for example.

The dicing die-bonding film 1 of the present embodiment is used by irradiating active energy rays (for example, ultraviolet rays) to cure the adhesive layer 22. Specifically, in a state where a die bonding layer 10 having a semiconductor wafer bonded to one surface thereof and an adhesive layer 22 bonded to the other surface of the die bonding layer 10 are laminated, at least the adhesive layer 22 is irradiated with ultraviolet light or the like. For example, ultraviolet rays or the like are irradiated from the side where the base material layer 21 is disposed, and the ultraviolet rays or the like having passed through the base material layer 21 reach the pressure-sensitive adhesive layer 22. The adhesive layer 22 is cured by irradiation with ultraviolet rays or the like.

Since the adhesive layer 22 is cured after irradiation, the adhesive force of the adhesive layer 22 can be reduced, and thus the die-bonding layer 10 (in a state where the semiconductor wafer is bonded) can be peeled off from the adhesive layer 22 relatively easily after irradiation.

The dicing die-bonding film 1 of the present embodiment may be provided with a release sheet covering one surface of the die-bonding layer 10 (the surface of the die-bonding layer 10 not overlapping with the adhesive layer 22) in a state before use. The release sheet is used for protecting the chip bonding layer 10, and is peeled off immediately before an adherend (e.g., a semiconductor wafer) is attached to the chip bonding layer 10.

As the release sheet, the same release sheet as described above can be used. The release sheet can be used as a support material for supporting the chip bonding layer 10. When the chip bonding layer 10 is stacked on the adhesive layer 22, a release sheet can be suitably used. Specifically, the chip bonding layer 10 can be superimposed on the adhesive layer 22 by superimposing the chip bonding layer 10 on the adhesive layer 22 in a state where the release sheet and the chip bonding layer 10 are stacked, and then peeling (transferring) the release sheet after the superimposition.

Since the dicing die-bonding film 1 of the present embodiment is configured as described above, the semiconductor wafer can be satisfactorily diced in the low-temperature expanding step described later.

Next, a description will be given of a method of manufacturing the dicing tape 20 and the dicing die-bonding film 1 according to the present embodiment.

The method for manufacturing the dicing die-bonding film 1 of the present embodiment includes:

a step of manufacturing a dicing tape 20 (a method of manufacturing a dicing tape), and a step of manufacturing a dicing die-bonding film 1 by superimposing the die-bonding layer 10 on the manufactured dicing tape 20.

The method for manufacturing a dicing tape (step of manufacturing a dicing tape) includes:

a synthesis step for synthesizing an acrylic polymer;

a pressure-sensitive adhesive layer production step of producing the pressure-sensitive adhesive layer 22 by volatilizing a solvent from a pressure-sensitive adhesive composition containing the acrylic polymer, the isocyanate compound, the polymerization initiator, the solvent, and other components added as appropriate depending on the purpose;

a substrate layer manufacturing step of manufacturing the substrate layer 21; and

and a laminating step of laminating the base material layer 21 and the pressure-sensitive adhesive layer 22 by bonding the pressure-sensitive adhesive layer 22 and the base material layer 21 to each other.

In the synthesis step, for example, a C9 to C11 alkyl (meth) acrylate monomer and a hydroxyl group-containing (meth) acrylate monomer are subjected to radical polymerization to synthesize an acrylic polymer intermediate.

The radical polymerization can be carried out by a conventional method. For example, the acrylic polymer intermediate can be synthesized by dissolving the monomers in a solvent, stirring the solution while heating, and adding a polymerization initiator. In order to adjust the molecular weight of the acrylic polymer, the polymerization may be carried out in the presence of a chain transfer agent.

Next, a part of the hydroxyl groups of the structural units of the hydroxyl group-containing (meth) acrylate included in the acrylic polymer intermediate and the isocyanate groups of the isocyanate group-containing polymerizable monomer are bonded by a urethanization reaction. Thus, a part of the structural units of the hydroxyl group-containing (meth) acrylate becomes the structural units of the polymerizable group-containing (meth) acrylate.

The carbamation reaction can be carried out by a conventional method. For example, the acrylic polymer intermediate and the isocyanate group-containing polymerizable monomer are stirred in the presence of a solvent and a urethane-forming catalyst while heating. Thus, the isocyanate group of the isocyanate group-containing polymerizable monomer can form a urethane bond with a part of the hydroxyl group of the acrylic polymer intermediate.

In the pressure-sensitive adhesive layer production step, for example, an acrylic polymer, an isocyanate compound, and a polymerization initiator are dissolved in a solvent to prepare a pressure-sensitive adhesive composition. The viscosity of the composition can be adjusted by changing the amount of the solvent. Next, the adhesive composition is applied to a release sheet. As the coating method, a general coating method such as roll coating, screen coating, gravure coating, or the like is used. The applied adhesive composition is cured by subjecting the applied composition to a desolvation treatment, a curing treatment, or the like, thereby producing the adhesive layer 22.

In the substrate layer production step, the substrate layer 21 can be produced by film formation by a usual method. Examples of the film forming method include a rolling film forming method, a casting method in an organic solvent, a inflation extrusion method in a closed system, a T-die extrusion method, and a dry lamination method. A coextrusion method may be used. As the base layer 21, a commercially available film or the like can be used.

In the laminating step, the pressure-sensitive adhesive layer 22 and the base layer 21 are laminated in a state of being laminated on the release sheet. The release sheet may be in a state of being superposed on the pressure-sensitive adhesive layer 22 until the time of use.

In order to promote the reaction between the crosslinking agent and the acrylic polymer and the reaction between the crosslinking agent and the surface portion of the base material layer 21, a curing step may be performed for 48 hours at 50 ℃.

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

The method for manufacturing a dicing die-bonding film (step of manufacturing a dicing die-bonding film) includes:

a resin composition preparation step of preparing a resin composition for forming the chip bonding layer 10;

a chip bonding layer production step of producing a chip bonding layer 10 from the resin composition; and

and a bonding step of bonding the chip bonding layer 10 to the adhesive layer 22 of the dicing tape 20 manufactured as described above.

In the resin composition preparation step, for example, an epoxy resin, a curing catalyst for an epoxy resin, an acrylic resin, a phenol resin, a solvent, and the like are mixed, and each resin is dissolved in the solvent to prepare a resin composition. The viscosity of the composition can be adjusted by changing the amount of the solvent. As these resins, commercially available products can be used.

In the die bonding layer forming step, for example, the resin composition prepared as described above is applied to a release sheet. The coating method is not particularly limited, and a general coating method such as roll coating, screen coating, gravure coating, or the like can be used. Next, the applied composition is cured by desolvation treatment, curing treatment, or the like as necessary, thereby producing the chip bonding layer 10.

In the bonding step, the release sheet is peeled off from each of the pressure-sensitive adhesive layer 22 and the die-bonding layer 10 of the dicing tape 20, and the die-bonding layer 10 and the pressure-sensitive adhesive layer 22 are bonded to each other so as to be in direct contact with each other. For example, the bonding may be performed by pressure bonding. The temperature at the time of bonding is not particularly limited, and is, for example, 30 ℃ to 50 ℃, preferably 35 ℃ to 45 ℃. The linear pressure at the time of bonding is not particularly limited, but is preferably 0.1kgf/cm or more and 20kgf/cm or less, and more preferably 1kgf/cm or more and 10kgf/cm or less.

The dicing die-bonding film 1 manufactured as described above is used as an auxiliary tool for manufacturing a semiconductor integrated circuit, for example. Specific examples of the use thereof will be described below.

A method of manufacturing a semiconductor integrated circuit generally includes a step of cutting out and assembling chips from a semiconductor wafer on which a circuit surface is formed.

This step includes, for example, the following steps: a half-cut step of forming a groove in the semiconductor wafer by processing the semiconductor wafer into chips (Die) by a dicing process, and grinding the semiconductor wafer to reduce the thickness; a mounting step of attaching one surface (for example, a surface opposite to a circuit surface) of the semiconductor wafer subjected to the half dicing process to the chip bonding layer 10 and fixing the semiconductor wafer to the dicing tape 20; an expanding step of expanding the interval between the semiconductor chips subjected to the half-cut processing; a pickup step of peeling the chip bonding layer 10 and the adhesive layer 22 and taking out the semiconductor chip (Die) in a state where the chip bonding layer 10 is bonded; and a Die bonding step of bonding the semiconductor chip (Die) with the Die bonding layer 10 bonded thereto to an adherend. In performing these steps, the dicing tape (dicing die-bonding film) of the present embodiment is used as a manufacturing aid.

In the half-cut step, as shown in fig. 2A to 2D, half-cut processing for cutting the semiconductor integrated circuit into chips (Die) is performed. Specifically, the wafer processing tape T is attached to the surface of the semiconductor wafer W opposite to the circuit surface. Further, the dicing ring R is attached to the wafer processing tape T. The dividing grooves are formed in a state where the wafer processing tape T is attached. The back grinding tape G is stuck to the surface on which the grooves are formed, and the wafer processing tape T stuck first is peeled off. The grinding process is performed with the back grinding tape G attached until the semiconductor wafer W has a predetermined thickness.

In the mounting step, as shown in fig. 3A to 3B, the dicing ring R is mounted on the pressure-sensitive adhesive layer 22 of the dicing tape 20, and the semiconductor wafer W subjected to the half-dicing process is bonded to the exposed surface of the chip bonding layer 10. Thereafter, the back grinding tape G is peeled off from the semiconductor wafer W.

In the expanding step, as shown in fig. 4A to 4C, the dicing ring R is attached to the adhesive layer 22 of the dicing tape 20, and then fixed to the holding tool H of the expanding apparatus. The cut die-bonding film 1 is stretched and spread in the planar direction by lifting up a lifting member U provided in the spreading device from below the cut die-bonding film 1. Thus, the half-cut semiconductor wafer W is cut under a specific temperature condition. The temperature is, for example, -20 to 0 ℃, preferably-15 to 0 ℃, and more preferably-10 to-5 ℃. The expansion state is released by lowering the jack-up member U (low-temperature expansion process up to this point). Further, in the expanding step, as shown in fig. 5A to 5B, the dicing tape 20 is stretched under a higher temperature condition to expand the area. Thereby, the cut adjacent semiconductor chips are separated in the plane direction of the thin film surface, and the cuts (gaps) are further enlarged (normal temperature expansion step).

In the pickup step, as shown in fig. 6, the semiconductor chip with the die bonding layer 10 attached thereto is peeled off from the adhesive layer 22 of the dicing tape 20. Specifically, the pin member P is raised to lift the semiconductor chip to be picked up via the dicing tape 20. The semiconductor chip lifted up is held by an adsorption jig J.

In the die bonding step, the semiconductor chip with the die bonding layer 10 attached thereto is bonded to an adherend.

As described above, the dicing die-bonding film 1 (dicing tape 20) according to the present embodiment is used in the above-described step, and in the low-temperature expanding step, the dicing tape 20 is stretched in a state where the wafer is bonded to the die-bonding layer 10 at 0 ℃ or lower, and the wafer is cut together with the die-bonding layer 10. Further, in the expanding step at normal temperature, the dicing tape 20 is stretched.

The temperature in the low-temperature expansion step is usually 0 ℃ or lower, for example, a temperature of-15 ℃ to 0 ℃. The temperature in the expansion step at normal temperature is, for example, 10 to 25 ℃.

The matters disclosed by the present specification include the following matters.

(1)

A dicing tape comprising a base material layer and an adhesive agent layer having higher adhesiveness than the base material layer,

(2)

The dicing tape according to the item (1), wherein a spectrum measured by differential scanning calorimetry of the substrate layer has an endothermic peak having a peak temperature of 100 ℃ or higher.

(3)

The dicing tape according to the above (2), wherein a temperature difference between a peak start point (point A) and a peak point (point C) in the endothermic peak is 40 ℃ or less.

(4)

The cleavage zone according to the above (2) or (3), wherein a temperature difference between a peak start point (point A) and a peak end point (point B) in the endothermic peak is 30 ℃ or more and 60 ℃ or less.

(5)

The dicing tape according to any one of the above (2) to (4), wherein the temperature at the peak start point (point A) in the endothermic peak is 70 ℃ or higher.

(6)

The dicing tape according to any one of the above (2) to (5), wherein the temperature of the peak ending point (point B) in the endothermic peak is 150 ℃ or lower.

(7)

The dicing tape according to any one of the above (1) to (6), wherein the base material layer has a single-layer structure or a laminated structure.

(8)

The dicing tape according to any one of the above (1) to (7), wherein the base material layer is composed of at least 3 layers.

(9)

The dicing tape according to the above (8), wherein the base layer has a 3-layer structure, and has two non-elastic layers (X, X) formed of a non-elastic body, and an elastic layer (Y) formed of an elastic body and disposed between the two non-elastic layers.

(10)

The dicing tape according to the above (9), wherein the base material layer has a 3-layer structure, and a ratio (Y thickness/X thickness) of a thickness of the inner layer to a thickness of 1 outer layer is 5 or more and 15 or less.

(11)

The dicing tape according to the above (9) or (10), wherein the non-elastomer layer (X) contains at least 1 selected from the group consisting of Low Density Polyethylene (LDPE), High Density Polyethylene (HDPE), and polypropylene.

(12)

The dicing tape according to any one of the above (9) to (11), wherein the elastomer layer (Y) comprises an ethylene-vinyl acetate copolymer (EVA).

(13)

The dicing tape according to any one of the above (1) to (11), wherein a ratio of a thickness of the pressure-sensitive adhesive layer to a total thickness of the dicing tape is 5% or more and 30% or less.

(14)

A dicing die-bonding film comprising the dicing tape according to any one of the above (1) to (13) and a die-bonding layer attached to the dicing tape.

(15)

The dicing die-bonding film according to the item (14), wherein the die-bonding layer contains at least one of a thermosetting resin and a thermoplastic resin.

(16)

The dicing die-bonding film according to the above (14) or (15), wherein the die-bonding layer has a thickness of 1 μm or more and 200 μm or less.

The dicing tape and the dicing die-bonding film according to the present embodiment are as exemplified above, but the present invention is not limited to the dicing tape and the dicing die-bonding film exemplified above.

That is, various forms used for a general dicing tape or dicing die-bonding film can be adopted within a range not to impair the effects of the present invention.

Examples

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

The dicing tape was manufactured as follows. Further, using the dicing tape, a dicing die-bonding film was manufactured.

< substrate layer >

Using the following products as raw materials, a substrate layer having 3 layers or a single layer was prepared.

Resin constituting the inner layer

The raw material name is as follows: ultrathene 626

Ethylene-vinyl acetate copolymer resin (EVA containing 15 mass% of vinyl acetate)

Manufactured by Tosoh Corp

Resin constituting the inner layer

The raw material name is as follows: ultrathene 633

Ethylene-vinyl acetate copolymer resin (EVA containing 20 mass% of vinyl acetate)

Manufactured by Tosoh Corp

Resin constituting the inner layer

The raw material name is as follows: evaflex V523

Ethylene-vinyl acetate copolymer resin (EVA containing 33 mass% of vinyl acetate)

Manufactured by DOW-MITSUI POLYCHEMICALS

Resin constituting the inner layer

The raw material name is as follows: evaflex P1007

Ethylene-vinyl acetate copolymer resin (EVA containing 9 mass% of vinyl acetate)

Manufactured by DOW-MITSUI POLYCHEMICALS

Resin constituting the base layer of comparative example

The raw material name is as follows: infuse 9530

Alpha-olefin block copolymer resin

Manufactured by Dow Chemical Co Ltd

Resin constituting the outer layer

The raw material name is as follows: WINTEC WFX4M

Metallocene polypropylene

Manufactured by Japan Polypropylene Ltd

(Forming of substrate layer)

The substrate layer was shaped using an extrusion T-die shaper. The extrusion temperature was 190 ℃. The substrate layer of the 3-layer laminated type was integrated by coextrusion molding using a T-die. After the integrated substrate layer (laminate) is sufficiently cured, the substrate layer is wound into a roll and stored.

The thickness ratio of each layer constituting the base material layer and the total thickness of the base material layer are shown in table 1.

< adhesive layer >

(preparation of adhesive layer (adhesive composition))

The following raw materials were mixed to prepare a first resin composition.

173 parts by mass of INA (isononyl acrylate)

54.5 parts by mass of HEA (hydroxyethyl acrylate)

0.46 part by mass of AIBN (2, 2' -azobisisobutyronitrile)

372 parts by mass of ethyl acetate

Next, the first resin composition was charged into a round-bottomed separable flask (capacity 1L), a thermometer, a nitrogen inlet tube, and a stirring blade. While the temperature of the first resin composition was adjusted to room temperature (23 ℃) with stirring, the inside of the round-bottom separable flask was replaced with nitrogen gas for 6 hours.

Subsequently, while nitrogen gas was flown into the round-bottom separable flask, the liquid temperature of the first resin composition was maintained at 62 ℃ for 3 hours while stirring the first resin composition. Thereafter, it was further held at 75 ℃ for 2 hours, thereby carrying out polymerization of the above-mentioned INA, HEA and AIBN, to prepare a second resin composition. Thereafter, the flow of nitrogen into the round-bottom separable flask was stopped.

After the second resin composition was cooled to room temperature, the following raw materials were added to the second resin composition.

2-Methacryloyloxyethyl isocyanate

Compound having polymerizable carbon-carbon double bond

Trade name "KARENZ MOI", manufactured by SHOWA AND ELECTRIC WORKS CO., LTD.) 52.5 parts by mass

0.26 parts by mass of dibutyltin dilaurate IV (Wako pure chemical industries, Ltd.)

The resulting third resin composition was stirred at 50 ℃ for 24 hours under an atmospheric atmosphere.

Finally, the following raw materials were added to 100 parts by mass of the polymer solid content of the third resin composition.

0.75 part by mass of an isocyanate compound (trade name "COLONATE L", manufactured by Tosoh Co., Ltd.)

2 parts by mass of a photopolymerization initiator (trade name "Omnirad 127", manufactured by IGM Resins Co., Ltd.)

Then, the third resin composition was diluted with ethyl acetate so that the solid content concentration reached 20 mass%, to prepare a pressure-sensitive adhesive composition.

< production of dicing tape >

The adhesive composition was applied to one surface of the base material layer using an applicator so that the thickness after drying became 10 μm. The base layer coated with the adhesive composition was dried by heating at 110 ℃ for 3 minutes to form an adhesive layer, thereby producing a dicing tape.

< preparation of dicing die-bonding film >

(preparation of chip bonding layer)

The following raw materials were added to methyl ethyl ketone and mixed to obtain a composition for a chip bonding layer having a solid content concentration of 20 mass%.

100 parts by mass of an acrylic resin (trade name: SG-P3, manufactured by Nagase Chemtex Co., Ltd., glass transition temperature of 12 ℃ C.)

46 parts by mass of an epoxy resin (trade name: JER1001, manufactured by Mitsubishi chemical corporation)

51 parts by mass of a phenol resin (trade name "MEH-7851 ss", manufactured by Minghe chemical Co., Ltd.)

191 parts by mass of spherical silica (trade name "SO-25R", manufactured by ADMATECHS Co.)

0.6 part by mass of a curing catalyst (trade name "CUREZOL PHZ", manufactured by Shikoku Kogyo Co., Ltd.)

Next, a release liner was prepared by subjecting a PET-based separator (thickness: 50 μm) to silicone treatment. The composition for chip bonding layer was applied to the treated surface of the release liner with an applicator so that the thickness after drying became 10 μm. The solvent was evaporated from the composition for die bonding layer by drying treatment at 130 ℃ for 2 minutes to obtain a die bonding sheet in which a die bonding layer was laminated on a release liner.

(attachment of chip bonding layer to dicing tape)

Next, the adhesive layer of the dicing tape is bonded to the die-bonding layer (the side on which the release sheet is not laminated) in the die-bonding sheet. Thereafter, the release liner was peeled off from the chip bonding layer, and a dicing die bonding film having a chip bonding layer was produced.

In the above operation, the dicing tapes and the dicing die-bonding films of the examples and comparative examples were respectively manufactured in accordance with the above-described methods. The composition of each dicing tape is shown in table 1.

[ Table 1]

The calculation method of the volume crystallinity is as follows. The volume crystallinity corresponding to the inner layer is calculated by multiplying the ratio of the heat absorption amount of the inner layer to the thickness of the inner layer and then multiplying the ratio by the specific gravity of the inner layer. In the same manner, the volume crystallinity was also calculated for the outer layer. Then, these calculated values are added. The total value was used as the volume crystallinity.

< measurement of Differential Scanning Calorimetry (DSC) >

The measurement samples were taken out from the dicing tapes of the examples and comparative examples. The measurement sample is taken out from the base material layer by cutting the base material layer in the thickness direction.

About 10mg of a sample for measurement was weighed using a commercially available DSC measuring apparatus, and the temperature was raised from room temperature (about 20 ℃) to 200 ℃ at a temperature rise rate of 5 ℃/min, and the measurement was performed under a nitrogen atmosphere.

The area of the endothermic peak appearing in the measurement spectrum, the peak start point of the endothermic peak, the peak top point of the peak, and the temperature at the peak end point were measured by the analysis software attached to the apparatus.

When a plurality of peaks appear in the measurement spectrum, the above-mentioned temperatures and the like are measured for each peak.

The details of the DSC measurement apparatus and analysis software are as follows.

A measuring device: manufactured by TA Instruments Japan

Device name DSC Q-2000

Analysis software: version A of TA Instruments Universal Analysis 20004.5

Fig. 7A and 7B show the spectra obtained by differential scanning calorimetry (DSC measurement) on the base layer of example 1. Fig. 7A and 7B show the same measurement results in different expressions, respectively. In fig. 7A, the oblique line in the spectrum indicates the temperature.

Similarly, the base material layer of comparative example 1 is shown in fig. 8A and 8B in the form of a differential scanning calorimetry (DSC measurement) spectrum.

< evaluation of Performance (evaluation of cuttability) >

Using the dicing die-bonding films manufactured in the examples and comparative examples, performance evaluation was performed as follows.

After a wafer processing tape (trade name "V-12 SR 2", manufactured by hitto electrician) was attached to one surface of a bare wafer (diameter 300mm), the bare wafer was fixed to a dicing ring via the wafer processing tape, and a lattice-shaped groove (25 μm wide, 100 μm deep) was formed so that a chip was a square of 2mm × 2mm from the side opposite to the side to which the wafer processing tape was attached, using a dicing apparatus (model 6361, manufactured by DISCO corporation). Next, a wafer processing tape (trade name "V-12 SR 2", manufactured by hitto electrical corporation) was peeled off from the wafer, a back surface grinding tape was attached to the surface on which the grooves were formed, and the bare wafer was ground so that the thickness thereof became 30 μm (0.030mm) by using a back surface grinder (model DGP8760, manufactured by DISCO corporation).

The ground wafer with the back-grinding tape was stuck to the surface of the die bonding film of the dicing die bonding tape at a temperature of 60 ℃. Next, the dicing die bonding film attached to the ground wafer is attached to a ring and fixed, and then the back side polishing tape is peeled off. Thereafter, the chip bonding layer was cleaved by a cold spreading unit under conditions of a spreading temperature of-5 ℃, a spreading rate of 100 mm/sec and a spreading amount of 14 mm. Next, room temperature expansion was carried out at room temperature under conditions of an expansion rate of 1 mm/sec and an expansion amount of 10 mm. The outer peripheral portion of the dicing die-bonding film was thermally shrunk under the conditions of a heating temperature of 200 ℃, a heating distance of 18mm, and a rotation speed of 5 °/second while maintaining the expanded state.

In the dicing die-bonding film after the heat shrinkage, the cleavage of the die-bonding layer was confirmed by a microscope, and the case where the cleavage ratio was 90% or more was regarded as good, the case where the cleavage ratio was less than 90% and 80% or more was regarded as Δ, and the case where the cleavage ratio was less than 80% was regarded as x.

The measurement results of Differential Scanning Calorimetry (DSC) and the results of performance evaluation (evaluation of cuttability) for the base material layers of the dicing tapes of the examples and comparative examples are shown in table 1.

As can be understood from the above evaluation results, the dicing die-bonding film of the example can favorably cleave the semiconductor wafer in the low-temperature expanding process, as compared with the dicing die-bonding film of the comparative example.

In the dicing tapes of examples, the bulk crystallinity of the base material layer calculated from the DSC measurement spectrum was 20J/cm³Above 120J/cm³The thickness of the base material layer is 80 μm or more.

Since the above-mentioned volume crystallinity is 20J/cm³As described above, the crystallinity of the base material layer is large, and thus the semiconductor wafer can be cut well in the low-temperature expanding step. Further, since the above-mentioned volume crystallinity is 120J/cm³Since the crystallinity of the base material layer is not increased more than necessary, the base material layer 21 can be prevented from cracking during expansion.

By using the dicing tape (dicing die-bonding film) of the embodiment having the base material layer having such physical properties in the manufacture of the semiconductor integrated circuit, the semiconductor wafer can be favorably cut in the low-temperature expanding step while suppressing cracking of the base material layer 21.

Industrial applicability

The dicing tape and the dicing die-bonding film of the invention can be suitably used as an auxiliary tool in, for example, manufacturing a semiconductor integrated circuit.

Claims

1. A dicing tape comprising a base material layer and an adhesive agent layer having higher adhesiveness than the base material layer,

the volume crystallinity of the substrate layer calculated from the differential scanning calorimetry measurement result is 20J/cm³Above 120J/cm³The thickness of the base material layer is 80 [ mu ] m or more.

2. The dicing tape according to claim 1, wherein a spectrum measured by differential scanning calorimetry of the substrate layer has an endothermic peak having a peak temperature of 100 ℃ or more.

3. A dicing die-bonding film comprising the dicing tape according to claim 1 or 2 and a die-bonding layer bonded to the dicing tape.