CN117716472A

CN117716472A - Adhesive tape

Info

Publication number: CN117716472A
Application number: CN202280047456.6A
Authority: CN
Inventors: 增田晃良; 佐藤浩和
Original assignee: Maxell Ltd
Current assignee: Maxell Ltd
Priority date: 2021-07-08
Filing date: 2022-06-15
Publication date: 2024-03-15
Also published as: JPWO2023281996A1; WO2023281996A1; KR20240031298A; TW202311043A

Abstract

The invention provides an adhesive tape for wafer processing, which has tensile stress suitable for a step of cutting an adhesive layer by expansion, uniform expansibility and high contractibility, and can eliminate tape looseness generated during expansion in a heating and contraction step. The adhesive tape for wafer processing comprises a base film and an adhesive layer, wherein the base film is a base film having 2 or more layers of a first resin layer and a second resin layer, each of which contains 80 mass% or more of an ionomer resin, the ionomer resin is formed of a resin having a Vicat softening temperature of 50-79 ℃ after a part of acid groups contained in an ethylene-unsaturated carboxylic acid copolymer are neutralized with zinc ions, and the content of constituent units derived from unsaturated carboxylic acid is 6.9-18.0 mass% and the concentration of zinc ions is 0.38-0.60 mmol per 1g of the ethylene-unsaturated carboxylic acid copolymer, wherein the total amount of constituent units of the ethylene-unsaturated carboxylic acid copolymer is 100 mass%.

Description

Adhesive tape

Technical Field

The present invention relates to an adhesive tape for wafer processing used in a process for manufacturing a semiconductor device, and more particularly, to an expandable adhesive tape for wafer processing for obtaining a semiconductor chip with a die bonding film (adhesive layer).

Background

In a process for manufacturing a semiconductor device such as an IC, a dicing tape including a base material and an adhesive layer may be used together with a die bonding film (hereinafter, referred to as an "adhesive layer" or an "adhesive film") to obtain a semiconductor chip having an adhesive film corresponding to a chip size for die bonding.

The dicing die bonding film is formed by providing a die bonding film (hereinafter, sometimes referred to as an "adhesive film" or an "adhesive layer") on an adhesive layer of a dicing tape so as to be peelable. Specifically, in the manufacture of semiconductor devices, for example, semiconductor wafers are attached to and placed on die bonding films, which are dicing die bonding films, and the semiconductor wafers are diced together with the die bonding films to obtain individual semiconductor chips with adhesive films. Then, the semiconductor chip is peeled (picked up) together with the die bonding film from the adhesive layer of the dicing tape as a semiconductor chip with the die bonding film, and the semiconductor chip is adhered to an adherend such as a lead frame, a wiring board, or another semiconductor chip via the die bonding film.

The dicing die bonding film is preferably used from the viewpoint of improving productivity, and as a method for obtaining a semiconductor chip with a die bonding film by using the dicing die bonding film, in recent years, a method of (1) utilizing DBG (Dicing Before Grinding) and a method of (2) utilizing invisible dicing (registered trademark) have been proposed as a method capable of suppressing pick-up failure caused by chipping of an adhesive layer and chipping of a thinned semiconductor wafer when dicing the semiconductor wafer into chips, instead of the conventional full-dicing cutting method using a dicing blade rotating at high speed.

In the method using DBG according to (1), first, a dicing blade is used to form a dicing groove of a predetermined depth on the front surface of a semiconductor wafer without completely cutting the semiconductor wafer, and then back grinding is performed, and the grinding amount is appropriately adjusted until the predetermined thickness is reached, thereby obtaining a semiconductor wafer divided into a plurality of semiconductor chips or a thinned semiconductor wafer capable of being singulated into a plurality of semiconductor chips. Then, the dicing tape is inflated (hereinafter, sometimes referred to as "cold inflation") at a low temperature (for example, 30 ℃ to 0 ℃) by adhering the divided pieces of the semiconductor wafer or the semiconductor wafer that can be singulated into semiconductor chips to the dicing die bonding film, so that the dicing die bonding film that is embrittled at a low temperature is cut (hereinafter, sometimes referred to as "dicing") along the dividing grooves to a size corresponding to the individual semiconductor chips or is diced together with the semiconductor wafer. The expansion of the dicing tape is performed by pushing up an expansion table provided below the dicing tape. Finally, by picking up the peeling from the adhesive layer of the dicing tape, individual semiconductor chips with the die bonding film can be obtained.

In the method for utilizing stealth dicing of (2), first, a semiconductor wafer thinned to a predetermined thickness by back grinding is stuck to a dicing die bonding film, and a laser is irradiated to the inside of the semiconductor wafer to selectively form a modified region (modified layer) and simultaneously form a dicing target line. Thereafter, the dicing tape is cold-expanded to spread the crack from the modified region perpendicularly to the semiconductor wafer, and the semiconductor wafer is diced along the dicing line together with the die bonding film which is brittle at a low temperature. Finally, by picking up, the semiconductor chips with the chip bonding films can be obtained one by peeling from the adhesive layer of the dicing tape. In this case, in order to surely cut the semiconductor wafer with the die bonding film, a stress sufficient for cutting the dicing tape and a uniform and isotropic expansibility have been required.

For example, patent document 1 discloses a substrate film comprising a plurality of layers of 2 or more layers having a lowermost layer formed of a thermoplastic resin having a vicat softening point of 80 ℃ or more specified in JIS K7206 and other layers formed of a thermoplastic resin having a vicat softening point of 50 ℃ or more and less than 80 ℃ specified in JIS K7206, and other layers other than the lowermost layer, in order to provide a wafer processing tape having uniform and isotropic expansibility which is not excessively softened during a heating process when using a thermosetting surface protection tape and which can be used in an expansion step of cutting an adhesive layer.

In the method using DBG according to (1), instead of forming a dicing groove on the surface of the semiconductor wafer by a dicing blade, a modified region is selectively provided in the semiconductor wafer by stealth dicing, and then the semiconductor wafer is thinned to a predetermined thickness by back grinding, whereby a semiconductor wafer with a die bonding film can be obtained as a divided body or a singulated semiconductor wafer with a die bonding film. This is a method called SDBG (Stealth Dicing Before Griding, stealth dicing before grinding).

However, in order to properly pick up the semiconductor chips with the die bonding films, a step of expanding the dicing tape around the normal temperature (hereinafter, sometimes referred to as "normal temperature expansion") is generally performed as a preceding step for the purpose of expanding the interval between the adjacent semiconductor chips with the die bonding films (hereinafter, sometimes referred to as "kerf width") cut in the cold expansion step. In this step, when the expansion table provided below the dicing tape is pushed up, the stress applied to the dicing tape at the edge portion of the expansion (expansion) table becomes larger than the stress at the center portion of the expansion table. Therefore, when the expansion table is lowered after normal temperature expansion to release the expanded state, a slack corresponding to the edge portion of the expansion table occurs in the outer peripheral portion of the dicing tape. Such loosening causes uneven or narrow intervals of the divided semiconductor chips, and causes defective products in the pickup process. Specifically, in the pick-up step, the semiconductor chip with the die bonding film may not be picked up properly from the adhesive layer of the dicing tape, and for example, when picking up the semiconductor chip, damage due to contact between the chip and the adjacent chip, re-adhesion due to contact between the adhesive layers, and the like may occur in the chip and the adjacent chip, and the pick-up yield may be lowered.

As means for eliminating such slackening of the dicing tape, there are known: for example, a heat shrinkage step (hereinafter, sometimes referred to as "heat shrinkage step") of heating a loose portion of the outer peripheral portion of the dicing tape by blowing hot air so that the surface temperature of the loose portion becomes about 80 ℃ to shrink the loose portion and return the same to an initial state. In order to properly perform this step, the dicing tape needs to have high heat shrinkage at a temperature of about 80 ℃. By this appropriate heat shrinkage step, the region (region to which the semiconductor wafer is attached) further inside than the outer peripheral portion of the dicing tape is brought into a tension state in which a predetermined degree of tension acts. As a result, the semiconductor chips can be held and fixed in a state in which the interval (dicing width) between the individual semiconductor chips is enlarged, and thus the individual semiconductor chips with the die bonding films that are diced can be appropriately picked up from the adhesive layer of the dicing tape.

For example, patent document 2 discloses an adhesive tape for fixing a semiconductor wafer, which has an adhesive layer on a base film having at least 1 layer of a layer containing an ionomer resin having a melting point of 60 to 80 ℃, in order to provide an adhesive tape for fixing a semiconductor wafer, which can cope with expansion of a chip interval due to an increase in a stretching ratio, can sufficiently remove sagging due to expansion by blowing hot air, and does not cause a storage error when a wafer cassette is stored after completion of pickup.

Further, patent document 3 discloses a substrate film comprising a thermoplastic crosslinked resin having a vicat softening point of 50 ℃ or more and less than 90 ℃ specified in JIS K7206 and an increase in stress due to thermal shrinkage of 9MPa or more, in order to provide a wafer processing tape having a uniform expansibility suitable for a step of cutting an adhesive layer by expansion and exhibiting sufficient contractibility in a thermal contraction step and causing no problem due to relaxation after the thermal contraction step.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2009-231700

Patent document 2: japanese patent laid-open No. 9-7976

Patent document 3: japanese patent laid-open No. 2011-216508

Disclosure of Invention

Problems to be solved by the invention

Since the wafer processing tape of patent document 1 uses the base film having the lowest layer formed of the thermoplastic resin having the vicat softening point of 80 ℃ or higher, the adhesive layer can be satisfactorily cut without sticking to the chuck table. However, there is no description about a heat shrinkage step for removing the slack of the dicing tape after expansion to secure the slit width between the individual semiconductor chips and a heat shrinkage property of the tape for wafer processing, and according to the study by the present inventors, if the vicat softening point of the thermoplastic resin used for the base film is high, for example, the heat shrinkage property when hot air is blown so that the surface temperature of the slack portion becomes about 80 ℃ may not be said to be sufficiently high, and the slack may not be restored to the initial state by the heat shrinkage step, and the slit width between the individual semiconductor chips may not be sufficiently secured. It is also unclear whether or not an adhesive layer having a high fluidity and a high thickness such as a lead embedding die bonding film described later can be cut.

In addition, since the adhesive tape for fixing a semiconductor wafer in patent document 2 has at least 1 layer of ionomer resin having a melting point of 60 to 80 ℃ as the base film, it is possible to sufficiently remove sagging due to expansion by blowing hot air in response to expansion of the die gap due to an increase in the stretching ratio, and it is possible to prevent occurrence of storage errors at the time of storing a wafer cassette after completion of pickup. However, in the above-mentioned heat shrinkage step, for example, when hot air is blown so that the surface temperature of the relaxed portion becomes about 80 ℃, if the melting point of the ionomer resin used for the base film is low, the resin is excessively softened during heat shrinkage and becomes fluidized, and therefore, there is a concern that the adhesive tape for fixing a semiconductor wafer may be deformed or may be fused at worst. In addition, there is no description of the adhesive layer at all, and when the adhesive tape for fixing a semiconductor wafer is applied to a method using DBG or dicing in a hidden manner, it is not clear whether or not there is a stress that can separate a semiconductor wafer together with a die bonding film (adhesive layer), and it is not clear whether or not a sufficient kerf width can be ensured even when the adhesive tape is supplied to a step of releasing an expanded state after thermal shrinkage to pick up a die.

In addition, since the tape for wafer processing in patent document 3 uses a base film formed of a thermoplastic crosslinked resin having a vicat softening point of 50 ℃ or more and less than 90 ℃ and a stress increase due to thermal shrinkage of 9MPa or more, the relaxation after the thermal shrinkage step is very small, and the severed semiconductor chip and the singulated adhesive can be stably fixed to the tape for wafer processing, and good pick-up property can be obtained. However, according to the studies by the present inventors, depending on the properties of the thermoplastic crosslinked resin used for the base film, the heat shrinkability when hot air is blown so that the surface temperature of the relaxed portion becomes about 80 ℃ may not be sufficiently high, and there is a fear that the relaxation cannot be returned to the original state by the heat shrinkage step, and the slit width between the individual semiconductor chips may not be sufficiently ensured. It is also unclear whether or not an adhesive layer having a high fluidity and a high thickness such as a lead embedding die bonding film described later can be cut.

As described above, in the conventional technology, although a certain effect is obtained in terms of eliminating the slack of the adhesive tape after expansion, there are cases where shrinkage due to heating is insufficient depending on the performance of the base film containing the thermoplastic crosslinked resin used, and the slack remains after the heat shrinkage step, and the cut semiconductor chips and the singulated adhesive layer cannot be stably fixed to the adhesive tape in a state where the slit width is enlarged, and there is still room for improvement because the adjacent semiconductor chips are broken by contact with each other or the adhesive layers are re-adhered by contact with each other, resulting in deterioration of the yield of the semiconductor component manufacturing process.

In addition, in recent years, with the reduction in thickness of semiconductor wafers, chip breakage is likely to occur during wire bonding in a multi-stage lamination process of semiconductor chips, and as a countermeasure for this problem, a wire-embedded die bonding film having a separator function has been proposed. The wire-embedding die-bonding film needs to embed the wire without any gap during die bonding, and tends to have a larger thickness and higher fluidity (lower melt viscosity at high temperature) than the conventional general-purpose die-bonding film. Therefore, such a wire-embedded die-bonding film is less likely to be separated during cold expansion than conventional general-purpose die-bonding films used in a state where the wire is not embedded in the adhesive layer, and reattachment of the separated die-bonding films having a large thickness and collision of the semiconductor chips tend to occur, resulting in poor pick-up property. If the expansion amount of the adhesive tape for wafer processing is increased in order to cope with this problem, the amount of relaxation may be increased, and it may be difficult to remove the relaxation by the heat shrinkage step. From such a viewpoint, therefore, the following adhesive tape for wafer processing is strongly desired: even the chip bonding film which is not easy to be cut, such as the lead-embedded chip bonding film, can be cut well, and the cut semiconductor chip and the singulated adhesive layer can be stably fixed on the adhesive tape in a state of sufficiently expanding the notch width.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide an adhesive tape for wafer processing, which has both: the adhesive layer is suitable for the step of cutting the adhesive layer by expansion, particularly the adhesive layer which is not easy to be cut, such as the lead embedded chip bonding film, and the tensile stress and the uniform expansibility, and the high contractibility of the adhesive tape which can eliminate the looseness generated during the expansion in the heating contraction step.

Means for solving the problems

That is, the present invention provides the following embodiments.

[1] An expandable adhesive tape for wafer processing, which is used when an adhesive layer is cut along a chip by expansion, comprises a base film and an adhesive layer provided on the base film,

the base film is formed of a laminated structure of 2 or more layers including at least a first resin layer containing an ionomer resin at a content ratio of 80 mass% or more and a second resin layer containing an ionomer resin of the same or different kind from the ionomer resin at a content ratio of 80 mass% or more,

the ionomer resins each contain an ethylene-unsaturated carboxylic acid copolymer as a matrix polymer of the resin and zinc ions, and the Vicat softening temperature defined in JIS K7206 has a value in the range of 50 ℃ as a lower limit and 79 ℃ as an upper limit,

In the ethylene-unsaturated carboxylic acid copolymer, when the total amount of the constituent units constituting the ethylene-unsaturated carboxylic acid copolymer is 100% by mass, the content of the constituent units derived from the unsaturated carboxylic acid has a value in the range of 6.9% by mass as a lower limit value and 18.0% by mass as an upper limit value,

the concentration of the zinc ion is in a range of 0.38mmol as a lower limit and 0.60mmol as an upper limit per 1g of the ethylene-unsaturated carboxylic acid copolymer.

[2] The adhesive tape for wafer processing according to the scheme [1],

in the ethylene-unsaturated carboxylic acid copolymer, the content of the constituent unit derived from the unsaturated carboxylic acid is in the range of 8.0 to 15.0 mass% based on 100 mass% of the total constituent units constituting the ethylene-unsaturated carboxylic acid copolymer.

[3] The adhesive tape for wafer processing according to the item [1] or [2],

the concentration of the zinc ion is in the range of 0.41mmol to 0.55mmol per 1g of the ethylene-unsaturated carboxylic acid copolymer.

[4] The adhesive tape for wafer processing according to any one of the aspects [1] to [3],

the total thickness of the base film is in the range of 60-150 [ mu ] m, the total thickness of all resin layers containing the ionomer resin in the base film in a content ratio of 80 mass% or more is in the range of 10-50 [ mu ] m, and the total thickness of all resin layers containing the ionomer resin in a content ratio of 80 mass% or more is 65% or more of the total thickness of the base film.

[5] The adhesive tape for wafer processing according to any one of the aspects [1] to [4],

the ethylene-unsaturated carboxylic acid-based copolymer includes at least one copolymer selected from the group consisting of ethylene- (meth) acrylic acid binary copolymer and ethylene- (meth) acrylic acid alkyl ester terpolymer.

[6] An adhesive tape for wafer processing comprising an adhesive layer provided on the adhesive layer of the adhesive tape for wafer processing according to any one of the aspects [1] to [5] in a releasable manner.

[7] The adhesive tape for wafer processing according to the above-mentioned aspect [6],

the adhesive layer contains, as a resin component, a glycidyl group-containing (meth) acrylate copolymer, an epoxy resin, and a phenolic resin.

[8] The adhesive tape for wafer processing according to the item [6] or [7],

the adhesive layer has a shear viscosity at 80 ℃ in the range of 200 Pa.s to 11,000 Pa.s.

[9] The adhesive tape for wafer processing according to the scheme [8],

the adhesive layer is formed by using 100 parts by mass of the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin and the phenolic resin as resin components,

(a) The glycidyl group-containing (meth) acrylate copolymer is contained in a range of 17 to 51 mass%, the epoxy resin is contained in a range of 30 to 64 mass%, the phenolic resin is contained in a range of 19 to 53 mass%, and the total amount of the resin components is adjusted to 100 mass%,

(b) The curing accelerator is contained in a range of 0.01 to 0.07 parts by mass based on 100 parts by mass of the total amount of the epoxy resin and the phenolic resin,

(c) The inorganic filler is contained in a range of 10 to 80 parts by mass based on 100 parts by mass of the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin.

[10] A method for manufacturing a semiconductor chip or a semiconductor device, wherein the adhesive tape for wafer processing according to any one of the aspects [1] to [9] is used.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, it is possible to provide an adhesive tape for wafer processing having both tensile stress suitable for a step of cutting an adhesive layer by expansion and uniform expansibility, and high contractibility capable of eliminating tape slackening generated at the time of expansion in a heat shrinkage step. That is, the adhesive layer can be satisfactorily cut, and the tape slack generated during expansion can be removed by the heat shrinkage step, so that the cut semiconductor chips and the singulated adhesive layer can be stably fixed to the adhesive tape for wafer processing while maintaining a sufficient slit width. As a result, the occurrence of breakage due to contact between adjacent semiconductor chips, re-adhesion due to contact between adhesive layers, and the like as described above is suppressed, and the pick-up property is improved. The same effect can be achieved even when a lead-embedded die bonding film having a large thickness and high fluidity is used as the adhesive layer. Further, a method for manufacturing a semiconductor chip or a semiconductor device using the adhesive tape for wafer processing can be provided.

Drawings

FIG. 1 is a cross-sectional view showing an example of a 2-layer structure of a base film to which the adhesive tape for wafer processing according to the present embodiment is applied.

FIG. 2 is a cross-sectional view showing an example of a 3-layer structure of a base film to which the adhesive tape for wafer processing according to the present embodiment is applied.

Fig. 3 is a cross-sectional view showing an example of a laminated structure of another form of a base film to which the adhesive tape for wafer processing according to the present embodiment is applied.

Fig. 4 is a cross-sectional view showing an example of the structure of an adhesive tape for wafer processing to which the present embodiment is applied.

Fig. 5 is a cross-sectional view showing an example of a dicing die-bonding film having a structure in which an adhesive layer (die-bonding film) is provided in a peelable manner on an adhesive tape (dicing tape) for wafer processing according to this embodiment.

FIG. 6 is a flowchart illustrating a method for manufacturing an adhesive tape for wafer processing.

Fig. 7 is a flowchart illustrating a method of manufacturing a semiconductor chip.

Fig. 8 is a perspective view showing a state in which an annular frame (wafer ring) is attached to the outer edge portion of the dicing die bonding film, and a semiconductor wafer which can be processed monolithically is attached to the center portion of the die bonding film.

Fig. 9 (a) to (f) are cross-sectional views showing an example of a grinding process of a semiconductor wafer in which a plurality of modified regions are formed by laser irradiation and a bonding process of the semiconductor wafer to a dicing die bonding film.

Fig. 10 (a) to (f) are cross-sectional views showing examples of manufacturing a semiconductor chip using a thin film semiconductor wafer having a plurality of modified regions to which dicing die bonding films are bonded.

Fig. 11 is a schematic cross-sectional view of one embodiment of a semiconductor device employing a stacked structure of semiconductor chips manufactured by using a dicing die bonding film to which the present embodiment is applied.

Fig. 12 is a schematic cross-sectional view of one embodiment of another semiconductor device using a semiconductor chip manufactured by using the dicing die bonding film according to the present embodiment.

Fig. 13 is a plan view for explaining a method of measuring the space (kerf width) between semiconductor chips after expansion.

Fig. 14 is an enlarged plan view of a center portion of the semiconductor wafer of fig. 13.

Detailed Description

Hereinafter, suitable embodiments of the present invention will be described in detail with reference to the accompanying drawings, as needed. The present invention is not limited to the following embodiments.

(Structure of adhesive tape for wafer processing)

Fig. 1 (a) and (b) are cross-sectional views showing an example of a 2-layer structure of a base film 1 to which the adhesive tape for wafer processing according to the present embodiment is applied. The substrate film 1 having a 2-layer structure of the adhesive tape for wafer processing according to the present embodiment may be one in which the ionomer resin contained in the first resin layer and the second resin layer at a content ratio of 80 mass% or more is the same (see (a) 1-a,1 types of 2 layers in fig. 1), or one in which the ionomer resin contained in the first resin layer and the second resin layer at a content ratio of 80 mass% or more is different (see (B) 1-B,2 types of 2 layers in fig. 1).

Fig. 2 (c) to (e) are cross-sectional views showing an example of a 3-layer structure of the base film 1 to which the adhesive tape for wafer processing according to the present embodiment is applied. The substrate film 1 having a 3-layer structure of the adhesive tape for wafer processing according to the present embodiment may be one in which the ionomer resin contained in the first resin layer, the second resin layer, and the third resin layer at a content ratio of 80 mass% or more is all the same (see (C) 1-C,1 type 3 layers of fig. 2), one in which the ionomer resin contained in the first resin layer and the second resin layer at a content ratio of 80 mass% or more is the same, and one in which the ionomer resin contained in the third resin layer at a content ratio of 80 mass% or more is different (see (D) 1-D,2 type 3 layers of fig. 2), or one in which the ionomer resin contained in the first resin layer and the second resin layer at a content ratio of 80 mass% or more is all different (see (E) 1-E,3 types 3 layers of fig. 2). The positions of the layers of the first resin layer, the second resin layer, and the third resin layer in the entire base film are not particularly limited.

Fig. 3 (f) and (g) are cross-sectional views showing examples of laminated structures of other forms of the base film 1 to which the adhesive tape for wafer processing according to the present embodiment is applied. The substrate film 1 having a 3-layer structure of the adhesive tape for wafer processing according to the present embodiment may be: the first resin layer and the second resin layer are composed of resins containing the same ionomer resin at a content ratio of 80 mass% or more, and the third resin layer is composed of resins other than resins containing the ionomer resin at a content ratio of 80 mass% or more constituting the first resin layer and the second resin layer (see (F) 1-F,2 types of 3 layers in fig. 3), and may be: the first resin layer and the second resin layer are composed of resins containing different types of ionomer resins at a content ratio of 80 mass% or more, and the third resin layer is composed of resins other than the resins containing ionomer resins at a content ratio of 80 mass% or more constituting the first resin layer and the second resin layer (see (G) 1-G,3 types of 3 layers of fig. 3). The positions of the layers of the first resin layer, the second resin layer, and the third resin layer in the entire base film are not particularly limited.

The base film 1 to which the adhesive tape for wafer processing according to the present embodiment is applied is formed of a laminated structure of 2 or more layers including at least a first resin layer containing an ionomer resin at a content ratio of 80 mass% or more and a second resin layer containing an ionomer resin of the same type or a different type from the ionomer resin at a content ratio of 80 mass% or more, and the number of layers is not particularly limited as long as the number of layers includes two layers of the first resin layer and the second resin layer, and the effect of the present invention is not impaired. The number of layers is preferably in the range of 2 layers to 5 layers from the viewpoint of mechanical properties and productivity of the base film 1. The positions of the layers of the first resin layer and the second resin layer in the entire base film are not particularly limited.

Fig. 4 is a cross-sectional view showing an example of the structure of an adhesive tape for wafer processing to which the present embodiment is applied. As shown in fig. 4, the adhesive tape 10 for wafer processing has a structure in which an adhesive layer 2 is provided on a base film 1. A typical example of such a laminated structure is dicing tape. Although not shown, a release substrate sheet (release liner) may be provided on the surface of the adhesive layer 2 of the adhesive tape 10 for wafer processing (the surface opposite to the surface facing the substrate film 1). The base film 1 is formed of a laminated structure of 2 or more layers including at least a first resin layer containing an ionomer resin at a content ratio of 80 mass% or more and a second resin layer containing an ionomer resin of the same kind or a different kind from the ionomer resin at a content ratio of 80 mass% or more. As the adhesive for forming the adhesive layer 2, for example, an active energy ray-curable acrylic adhesive or the like is used which cures and shrinks by irradiation with active energy rays such as ultraviolet rays (UV) to reduce the adhesive force to an adherend.

Fig. 5 is a cross-sectional view showing an example of a structure in which the adhesive layer 3 is provided in a releasable manner on the adhesive tape 10 for wafer processing to which the present embodiment is applied. The adhesive layer 3 is detachably adhered and laminated on the adhesive layer 2 of the adhesive tape 10 for wafer processing. A typical example of such a laminated structure is the dicing die bonding film 20.

The dicing die bonding film 20 having this structure is used in a semiconductor manufacturing process, for example, as follows. The semiconductor wafer having the thin film with the dividing grooves formed on the surface thereof by the doctor blade and the semiconductor wafer having the thin film with the modified layer formed therein by the laser are stuck (bonded) to the die bonding film (adhesive layer) 3 of the dicing die bonding film 20, and the semiconductor wafer is diced together with the die bonding film 3 by cold expansion, whereby the individual semiconductor chips with the die bonding film 3 are obtained. Alternatively, the thin semiconductor wafer is stuck to (adhered to) the die bonding film 3 of the dicing die bonding film 20, a modified layer is formed in the semiconductor wafer by laser light in this state, and then the semiconductor wafer is diced together with the die bonding film 3 by cold expansion, thereby obtaining individual semiconductor chips with the die bonding film 3. Alternatively, the semiconductor wafer divided bodies including a plurality of semiconductor chips are stuck and held on the die bonding film 3 of the dicing die bonding film 20 by transfer from the back grinding tape, and the die bonding film 3 is diced along the semiconductor chips by cold expansion, thereby obtaining individual semiconductor chips with the die bonding film 3.

Next, after the slit width between the semiconductor chips with the die bonding films 3 is sufficiently expanded by normal temperature expansion, the semiconductor chips with the die bonding films 3 are peeled from the adhesive layer 2 of the adhesive tape (dicing tape) 10 for wafer processing by a pick-up process. The obtained semiconductor chip with the die bonding film (adhesive film) 3 is adhered to an adherend such as a lead frame, a wiring board, or another semiconductor chip via the die bonding film (adhesive film) 3. Although not shown, a releasable base sheet (release liner) may be provided on the surface of the adhesive layer 2 (the surface opposite to the surface facing the base film 1) and the surface of the die-bonding film 3 (the surface opposite to the surface facing the adhesive layer 2) of the adhesive tape for wafer processing (dicing tape) 10.

(adhesive tape for wafer processing)

Substrate film

The base film 1 of the adhesive tape 10 for wafer processing of the present invention is formed of a laminate structure of 2 or more layers including at least a first resin layer containing a specific ionomer resin (described later in detail) at a content ratio of 80 mass% or more and a second resin layer containing a specific ionomer resin of the same kind or a different kind from the above ionomer resin at a content ratio of 80 mass% or more. When the base film 1 has only 1 resin layer containing an ionomer resin, that is, when the base film 1 is formed of a single layer of the resin layer containing an ionomer resin, it is necessary to increase the extrusion flow rate of the resin particularly when the thickness of the base film 1 is increased, and therefore, the resin pressure in the extruder and the engine load may be excessively increased during film formation, and the film formation accuracy of the base film 1 may be deteriorated, and it may become difficult to stably perform long film formation. As a result, when the base film 1 is wound, unnecessary wrinkles may occur, and problems such as poor appearance and reduced pickup yield may occur. On the other hand, when the base film is formed by laminating at least 2 or more layers including the first resin layer and the second resin layer containing the ionomer resin, the extrusion flow rate can be controlled without excessively increasing the resin pressure and the engine load in the extruder, compared with the case where the base film 1 having the same thickness is produced in a single layer structure, and therefore, the base film 1 is suitable from the viewpoints of film formation accuracy and stable film formation, and unnecessary wrinkles do not occur. In addition, the substrate film 1 is also suitable in terms of improving the film forming speed, easily controlling the balance of physical properties such as tensile stress and uniform expansibility at the time of expansion, and contractibility in the heat shrinkage step.

The term "contained in a content ratio of 80 mass% or more" means that: the content ratio of the specific ionomer resin is 80 mass% or more, based on 100 mass% of the total mass of the resins in the first resin layer and the second resin layer. The content ratio of the specific ionomer resin is preferably in the range of 85 mass% to 100 mass%, more preferably in the range of 90 mass% to 100 mass%. That is, the first resin layer and the second resin layer of the base film 1 may be composed of only the specific ionomer resin. When the content ratio of the specific ionomer resin is less than 80 mass%, mechanical properties exhibited by a suitable and highly crosslinked structure of the ionomer resin, that is, tensile stress and uniform expansibility at the time of expansion of the adhesive tape 10 for wafer processing, and contractibility in the heat shrinkage process become insufficient, and as a result, the die bonding film (adhesive layer) 3 may not be satisfactorily cut, or a notch width between individual semiconductor chips may not be sufficiently ensured, and good pick-up property may not be obtained.

The number of resin layers of the base film 1 formed of the laminated structure of 2 or more layers is not particularly limited, but is preferably in the range of 2 or more layers and 5 or less layers, and is preferably in the range of 2 or more layers and 3 or less layers, from the viewpoints of the characteristics of the base film 1, productivity, and the like. As will be described later, the total thickness of all resin layers containing the specific ionomer resin in the substrate film 1 at a content ratio of 80 mass% or more is preferably 65% or more of the total thickness of the substrate film 1. More preferably, the content is 80% to 100%, and still more preferably, the content is 90% to 100%. For example, in the case where the base film 1 is configured by a laminated structure of 3 layers including a third resin layer in addition to the first resin layer and the second resin layer, first, as shown in fig. 2, the third resin layer may be configured by a resin containing the specific ionomer resin at a content of 80 mass% or more, or may be configured by only the specific ionomer resin, similarly to the first resin layer and the second resin layer. As shown in fig. 3, the third resin layer may be made of a resin other than the resin containing the specific ionomer resin in a content ratio of 80 mass% or more constituting the first resin layer and the second resin layer. In the case of the base film 1 having the former structure (the form shown in fig. 2), the total thickness of all resin layers including the specific ionomer resin in a content ratio of 80 mass% or more is preferably 100% of the total thickness of the base film 1.

On the other hand, in the case of the base film 1 having the latter structure (the form shown in fig. 3), the total thickness of the first resin layer and the second resin layer containing the specific ionomer resin at a content ratio of 80 mass% or more is preferably 65% or more, more preferably 80% or more and 99% or less, and still more preferably 90% or more and 99% or less of the total thickness of the base film 1. When the total of the thicknesses of the resin layers including the specific ionomer resin in the content ratio of 80 mass% or more is smaller than 65% of the total thickness of the base film 1, mechanical properties exhibited by an appropriate and highly crosslinked structure of the ionomer resin, that is, tensile stress and uniform expansibility at the time of expansion and contractibility in the heat shrinkage step of the adhesive tape 10 for wafer processing become insufficient, and as a result, the die bonding film (adhesive layer) 3 may not be satisfactorily cut, or a notch width between individual semiconductor chips may not be sufficiently ensured, and good pick-up may not be obtained.

< ionomer resin >)

The specific ionomer resin contained in the first resin layer and the second resin layer of the base film 1 of the present embodiment at a content ratio of 80 mass% or more will be described.

The specific ionomer resins each contain an ethylene-unsaturated carboxylic acid copolymer as a matrix polymer of the resin and zinc ions, and the vicat softening temperature defined in JIS K7206 has a value in the range of 50 ℃ as a lower limit and 79 ℃ as an upper limit. Regarding the above-mentioned ethylene-unsaturated carboxylic acid-based copolymer, the content ratio of the constituent unit derived from the unsaturated carboxylic acid has a value in the range of 6.9 mass% as the lower limit value and 18.0 mass% as the upper limit value, when the total amount of constituent units constituting the above-mentioned ethylene-unsaturated carboxylic acid-based copolymer is 100 mass%. Further, the concentration of the zinc ion per 1g of the ethylene-unsaturated carboxylic acid-based copolymer has a value in the range of 0.38mmol as a lower limit value and 0.60mmol as an upper limit value.

In the ionomer resin used for the base film 1, by properly neutralizing the acid groups of the ethylene-unsaturated carboxylic acid-based copolymer with zinc ions by setting the content ratio of the constituent units derived from unsaturated carboxylic acids and the concentration of zinc ions contained in the ethylene-unsaturated carboxylic acid-based copolymer to the above-described ranges, the development of ionic aggregates (clusters) formed by the aggregates of the ionic bonds of carboxylate ions derived from the acid groups of unsaturated carboxylic acids and zinc ions in the continuous layer of the ethylene-unsaturated carboxylic acid-based copolymer becomes sufficient and proper, and the crosslinking morphology is optimized, so that it is possible to realize a highly shrinkable adhesive tape for wafer processing having both tensile stress and uniform expansibility suitable for the cold expansion step and capable of eliminating tape relaxation generated during expansion in the heat shrinkage step, as will be described in detail later.

The ethylene-unsaturated carboxylic acid copolymer may be an at least binary copolymer obtained by copolymerizing ethylene and an unsaturated carboxylic acid, or may be a ternary or higher multipolymer obtained by copolymerizing a third, a fourth and other copolymerization components. The ethylene-unsaturated carboxylic acid copolymer may be used alone or in combination of two or more.

Examples of the unsaturated carboxylic acid constituting the ethylene-unsaturated carboxylic acid binary copolymer include unsaturated carboxylic acids having 4 to 8 carbon atoms such as acrylic acid, methacrylic acid, ethacrylic acid, itaconic anhydride, fumaric acid, crotonic acid, maleic acid, and maleic anhydride. Among these, acrylic acid or methacrylic acid is preferable as the unsaturated carboxylic acid.

When the ethylene-unsaturated carboxylic acid copolymer is a ternary or higher order copolymer, the copolymer may contain, in addition to ethylene and the unsaturated carboxylic acid constituting the copolymer, a third copolymer component, a fourth copolymer component, and the like, which form the copolymer. Examples of the other copolymerizable components such as the third and fourth copolymerizable components include unsaturated carboxylic acid esters, unsaturated hydrocarbons, vinyl esters, oxides such as vinyl sulfate and vinyl nitrate, halogen compounds, vinyl-containing primary amine, secondary amine compounds, carbon monoxide, sulfur dioxide, and the like. Among these, unsaturated carboxylic acid esters and unsaturated hydrocarbons are preferable as other copolymerization components.

The unsaturated carboxylic acid ester is preferably an unsaturated carboxylic acid alkyl ester, and the number of carbon atoms in the alkyl moiety of the alkyl ester is preferably 1 to 12, more preferably 1 to 8, and still more preferably 1 to 4. Examples of the alkyl moiety include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, 2-ethylhexyl, and isooctyl.

Specific examples of the above-mentioned unsaturated carboxylic acid alkyl esters include unsaturated carboxylic acid alkyl esters having an alkyl moiety with a carbon number of 1 to 12 (for example, alkyl acrylates such as methyl acrylate, ethyl acrylate, isobutyl acrylate, n-butyl acrylate, and isooctyl acrylate, alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and isobutyl methacrylate, and alkyl maleates such as dimethyl maleate and diethyl maleate). Of these, alkyl (meth) acrylates having 1 to 4 carbon atoms in the alkyl moiety are more preferable. From the viewpoints of controlling the vicat softening temperature and uniform expansion including suppressing necking phenomenon at the time of expansion of the adhesive tape 10 for wafer processing, isobutyl methacrylate having the alkyl group with the carbon number of 4 is particularly preferable.

Examples of the unsaturated hydrocarbon include propylene, butene, 1, 3-butadiene, pentene, 1, 3-pentadiene, and 1-hexene.

Examples of the vinyl ester include vinyl acetate and vinyl propionate, and examples of the halogen compound include vinyl chloride and vinyl fluoride.

The form of the ethylene-unsaturated carboxylic acid copolymer may be any of a block copolymer, a random copolymer, and a graft copolymer, and may be any of a binary copolymer and a ternary or higher order multipolymer. Among them, a binary random copolymer, a ternary random copolymer, a graft copolymer of a binary random copolymer or a graft copolymer of a ternary random copolymer is preferable, and a binary random copolymer or a ternary random copolymer is more preferable, and a ternary random copolymer is further preferable from the viewpoint of uniform expansion of the adhesive tape 10 for wafer processing at the time of expansion.

As a specific example of the above-mentioned ethylene-unsaturated carboxylic acid copolymer, ethylene- (meth) acrylic acid binary copolymers such as ethylene-acrylic acid copolymer and ethylene-methacrylic acid copolymer, ethylene- (meth) acrylic acid- (meth) alkyl acrylate ternary copolymers such as ethylene-methacrylic acid-isobutyl acrylate copolymer, and ethylene- (meth) acrylic acid- (meth) alkyl acrylate ternary copolymers such as ethylene-methacrylic acid-isobutyl acrylate copolymer are preferable from the viewpoint of uniform expansion of the adhesive tape 10 for wafer processing at the time of expansion. Further, commercially available products sold as ethylene-unsaturated carboxylic acid-based copolymers may be used, and for example, nucrel (registered trademark) series manufactured by dupont polymerization chemical company, san france may be used.

Regarding the above-mentioned ethylene-unsaturated carboxylic acid-based copolymer, the content ratio of the constituent unit derived from the unsaturated carboxylic acid has a value in the range of 6.9 mass% as the lower limit value and 18.0 mass% as the upper limit value, when the total amount of constituent units constituting the above-mentioned ethylene-unsaturated carboxylic acid-based copolymer is 100 mass%. The lower limit of the content ratio of the constituent units derived from the unsaturated carboxylic acid is preferably 8.0% by mass, more preferably 10.0% by mass. On the other hand, the upper limit value is preferably 15.0 mass%, more preferably 12.0 mass%. In the specific ionomer resin containing the ethylene-unsaturated carboxylic acid copolymer as a matrix polymer, the acid groups (carboxyl groups) of the ethylene-unsaturated carboxylic acid copolymer are neutralized with zinc ions in an arbitrary proportion, that is, a structure similar to crosslinking between macromolecules is formed, but when the content of the constituent units derived from the unsaturated carboxylic acid is less than 6.9 mass%, the crosslinking effect by zinc ions is small, and in the continuous layer of the ethylene-unsaturated carboxylic acid copolymer, the development of ion aggregates (clusters) formed by an aggregate of ionic bonds between carboxylate ions of the acid groups derived from the unsaturated carboxylic acid and zinc ions may become insufficient, and thus the tensile stress and uniform expansibility at the time of expansion and the contractibility in the heat contraction step may become insufficient in the adhesive tape 10 for wafer processing.

As a result, the die bonding film (adhesive layer) 3 may not be satisfactorily cut, or a slit width between individual semiconductor chips may not be sufficiently ensured, and good pick-up may not be obtained. In addition, the vicat softening temperature may be excessively increased. On the other hand, when the content of the constituent unit derived from the unsaturated carboxylic acid exceeds 18.0 mass%, the mechanical properties of the base film 1 may become insufficient. In addition, depending on the content ratio of the unsaturated carboxylic acid ester, the vicat softening temperature described later may be excessively lowered. When the content ratio of the constituent units derived from the unsaturated carboxylic acid is within the above range, it is easy to achieve both moderate tensile stress and uniform expansion at the time of expansion of the adhesive tape 10 for wafer processing and shrinkage in the heat shrinkage step.

In the ethylene-unsaturated carboxylic acid copolymer, the content of the constituent unit derived from the unsaturated carboxylic acid ester preferably has a value in the range of 0 mass% as a lower limit and 16.0 mass% as an upper limit, when the total amount of constituent units constituting the ethylene-unsaturated carboxylic acid copolymer is 100 mass% based on the total amount of constituent units. The lower limit of the content ratio of the constituent units derived from the unsaturated carboxylic acid ester is more preferably 1.5 mass%, and still more preferably 5.0 mass%, from the viewpoint of uniform expansibility including suppression of the necking phenomenon at the time of expansion of the adhesive tape 10 for wafer processing. On the other hand, the upper limit value is more preferably 15.0 mass%, and still more preferably 12.0 mass%. When the content of the constituent unit derived from the unsaturated carboxylic acid ester exceeds 16.0 mass%, the vicat softening temperature described later may be excessively lowered depending on the content of the unsaturated carboxylic acid. In addition, the base film 1 may be agglomerated or welded.

In the present invention, when the ethylene-unsaturated carboxylic acid-based copolymer is an ethylene-unsaturated carboxylic acid binary copolymer, the content of the constituent unit derived from ethylene is in the range of 82.0 mass% to 93.1 mass% inclusive, and the content of the constituent unit derived from an unsaturated carboxylic acid is in the range of 6.9 mass% to 18.0 mass% inclusive, based on 100 mass% of the total amount of constituent units constituting the ethylene-unsaturated carboxylic acid-based copolymer. More preferred are: the content of the constituent unit derived from ethylene is in the range of 85.0 to 92.0 mass%, and the content of the constituent unit derived from an unsaturated carboxylic acid is in the range of 8.0 to 15.0 mass%.

Further, as a preferable copolymerization ratio when the ethylene-unsaturated carboxylic acid copolymer is an ethylene-unsaturated carboxylic acid ester terpolymer, when the total amount of constituent units constituting the ethylene-unsaturated carboxylic acid copolymer is 100% by mass, the content ratio of constituent units derived from ethylene is in the range of 66.0% by mass to 91.6% by mass, the content ratio of constituent units derived from unsaturated carboxylic acid is in the range of 6.9% by mass to 18.0% by mass, the content ratio of constituent units derived from unsaturated carboxylic acid ester is in the range of 1.5% by mass to 16.0% by mass, and the total amount is adjusted to 100% by mass. More preferred are: the content of the constituent unit derived from ethylene is in the range of 70.0 to 87.0 mass%, the content of the constituent unit derived from an unsaturated carboxylic acid is in the range of 8.0 to 15.0 mass%, and the content of the constituent unit derived from an unsaturated carboxylic acid ester is in the range of 5.0 to 15.0 mass%.

Typically, ionomer resins are: the specific ionomer resin used in the substrate film 1 of the present embodiment is the following ionomer resin from the viewpoint of stabilization of the crosslinked structure (strong crosslinking bond) by neutralizing the acid groups (carboxyl groups) of the ethylene-unsaturated carboxylic acid copolymer as the matrix polymer of the resin with metal ions such as lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, zinc ions, magnesium ions, and manganese ions in an arbitrary ratio: an ionomer resin comprising an ethylene-unsaturated carboxylic acid copolymer as a base polymer of the resin and zinc ions, wherein at least a part of acid groups of the ethylene-unsaturated carboxylic acid copolymer as the base polymer of the resin is neutralized with zinc ions as 2-valent metal ions.

Examples of the zinc ion supply source include zinc oxide, hydroxide, carbonate, bicarbonate, acetate, formate, and organic acid salt. Specifically, examples thereof include zinc oxide, zinc hydroxide, zinc acetate, zinc stearate, and basic zinc carbonate. Among these, zinc oxide and zinc stearate are preferable. These zinc ion sources may be used singly or in combination of two or more.

The specific ionomer resin is obtained by adding zinc ions to an ethylene-unsaturated carboxylic acid copolymer, which is a base polymer of the resin, and neutralizing (crosslinking) acid groups (carboxyl groups) of the copolymer in an arbitrary ratio by the zinc ions, wherein the ethylene-unsaturated carboxylic acid copolymer is adjusted so that the content of constituent units derived from unsaturated carboxylic acids is in a range of 6.9 mass% as a lower limit and 18.0 mass% as an upper limit. Here, in order to achieve both uniform expansion properties at the time of expansion and shrinkage properties in the heat shrinkage step of the adhesive tape 10 for wafer processing, not all ionomer resins are acceptable, and the concentration of the zinc ions relative to the ethylene-unsaturated carboxylic acid copolymer which defines the content ratio of the constituent units derived from the unsaturated carboxylic acid is extremely important. That is, in the specific ionomer resin applied to the base film 1 of the present embodiment, the concentration of the zinc ion is adjusted to a value within a range of 0.38mmol as a lower limit and 0.60mmol as an upper limit for every 1g of the ethylene-unsaturated carboxylic acid-based copolymer. The lower limit of the concentration of zinc ions is preferably 0.41mmol, more preferably 0.46mmol. On the other hand, the upper limit value is preferably 0.55mmol, more preferably 0.52mmol.

When the concentration of the zinc ions is less than 0.38mmol, the crosslinking effect of the ethylene-unsaturated carboxylic acid-based copolymer by the zinc ions is small, and in the continuous layer of the ethylene-unsaturated carboxylic acid-based copolymer, the development of ionic aggregates (clusters) formed by aggregates of carboxylate ions derived from the acid groups of the unsaturated carboxylic acid and ionic bonds of the zinc ions becomes insufficient, and therefore, the uniform expansion property at the time of expansion and the shrinkage property in the heat shrinkage step of the adhesive tape 10 for wafer processing become insufficient, and as a result, the slit width between individual semiconductor chips may not be sufficiently ensured, and good pick-up property may not be obtained. On the other hand, when the concentration of the zinc ions exceeds 0.60mmol, the melt viscosity of the resin may excessively increase and the resin pressure in the extruder may increase, and the engine load may increase, thereby making it difficult to stably produce a film, depending on the content of the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer as the matrix polymer of the specific ionomer resin.

If the concentration of the zinc ions is within the above range, in the continuous layer of the ethylene-unsaturated carboxylic acid-based copolymer, the development of ionic aggregates (clusters) formed by aggregates of carboxylate ions from the acid groups of the unsaturated carboxylic acid and ionic bonds of the zinc ions becomes sufficient and appropriate, and therefore, even if the base film 1 is expanded, the ionic aggregates (clusters) are not easily broken by the crosslinking effect thereof, and the number of molecular chains between the ionic aggregates increases while expanding, exhibiting moderate tensile stress. On the other hand, in the heat shrinkage step after expansion, the entropy elasticity strongly acts, and the stretched molecules tend to return to the original state. That is, the substrate film 1 is sufficiently deformed by the tensile stress at the time of stretching and the recovery force at the time of heating, and the wafer processing adhesive tape 10 can be made to have both of moderate tensile stress and uniform expansion at the time of expansion and contractility at the time of heat shrinkage. As a result, the adhesive layer 3 is satisfactorily severed, and the dicing width between the individual semiconductor chips is sufficiently ensured, thereby achieving satisfactory pick-up performance.

Further, regarding the specific ionomer resin, the vicat softening temperature defined in JIS K7206 has a value in the range of 50 ℃ as a lower limit value and 79 ℃ as an upper limit value. The lower limit of the vicat softening temperature is preferably 54 ℃, more preferably 57 ℃. On the other hand, the upper limit value is preferably 74 ℃, more preferably 64 ℃. When the vicat softening temperature of the specific ionomer resin is less than 50 ℃, blocking may occur during film formation or during adhesive tape production. In the heat shrinkage step, for example, wen Fengshi is blown so that the surface temperature of the relaxed portion reaches about 80 ℃, and the resin is excessively softened and fluidized during heat shrinkage, so that the adhesive tape 10 for wafer processing may be deformed or fused more than necessary. On the other hand, when the vicat softening temperature of the specific ionomer resin is 80 ℃ or higher, for example, the heat shrinkage when hot air is blown so that the surface temperature of the relaxed portion reaches about 80 ℃ becomes insufficient, and as a result, the slit width between individual semiconductor chips may not be sufficiently ensured, and good pick-up properties may not be obtained. If the vicat softening temperature of the specific ionomer resin is within the above range, the adhesive tape 10 for wafer processing can be made to have both tensile stress and uniform expansion suitable for the step of cutting the adhesive layer by expansion (expansion step) and high shrinkage (recovery) suitable for the step of eliminating and removing the tape relaxation generated during expansion (heat shrinkage step), in combination with the appropriate crosslinking effect by the zinc ions.

As described above, the specific ionomer resin contained in the first resin layer and the second resin layer included in the base film 1 at a content ratio of 80 mass% or more is described, and when the base film 1 is formed of a laminated structure of 3 or more layers including other resin layers similar to the first resin layer and the second resin layer in addition to the first resin layer and the second resin layer (for example, the form shown in fig. 2), the specific ionomer resin may be used as the ionomer resin contained in the other resin layer at a content ratio of 80 mass% or more.

< other resin >)

The first resin layer and the second resin layer included in the base film 1 may contain other resins than the specific ionomer resin in a content ratio of 20 mass% or less, within a range that does not hinder the effects of the present invention, that is, when the mass of the entire resin in the first resin layer and the second resin layer is 100 mass% based on the total mass of the resin. In the case where the third, fourth, etc. resin layers laminated on the first and second resin layers contain the specific ionomer resin at a content ratio of 80 mass% or more, the resin other than the specific ionomer resin may be contained at a content ratio of 20 mass% or less in the same manner. Further, in the case where another resin layer is laminated on the first resin layer and the second resin layer, the other resin layer may be composed of another resin other than the resin containing the specific ionomer resin at a content ratio of 80 mass% or more constituting the first resin layer and the second resin layer.

The other resin is not particularly limited, but is preferably a thermoplastic resin. Examples of the thermoplastic resin include, for example, an ionomer resin other than the specific ionomer resin, a thermoplastic olefin-based copolymer, a thermoplastic polyurethane, a thermoplastic polyamide, a thermoplastic styrene-based resin, a thermoplastic polyester, a thermoplastic acrylic resin, a thermoplastic polyolefin, a thermoplastic polydiene, a thermoplastic polyether-polyolefin-based copolymer, a thermoplastic polyether-polyamide-based copolymer, and other thermoplastic resins (including thermoplastic elastomers). In addition, a resin obtained by crosslinking a thermoplastic olefin copolymer and a thermoplastic polyolefin by irradiation with electron rays may be used. Among these, the thermoplastic resin is preferably an ethylene-propylene copolymer elastomer, a thermoplastic olefin copolymer such as an ethylene-1-butene copolymer elastomer, a thermoplastic polyamide such as nylon 6 or nylon 6/12, or a thermoplastic polyether-polyolefin copolymer, and more preferably a thermoplastic polyamide from the viewpoint of the severability of the adhesive layer 3. These thermoplastic resins may be used singly or in combination of two or more.

In the case where the first resin layer, the second resin layer, and the other resin layer are composed of a mixed resin containing other resins than the specific ionomer resin in a content ratio of 20 mass% or less, the vicat softening temperature of the other resins is not particularly limited, and is preferably appropriately selected so that the vicat softening temperature of the mixed resin is in a range of 50 ℃ or more and less than 80 ℃. In the case where the other resin layers laminated on the first resin layer and the second resin layer are made of other resins than the resin containing the specific ionomer resin in a content ratio of 80 mass% or more, the vicat softening temperature of the other resins is preferably in a range of 50 ℃ or more and less than 80 ℃.

< other Components >)

The resin used for each resin layer constituting the base film 1 of the present embodiment may contain other components than the resin according to the present embodiment within a range that does not impair the effects of the present invention. Examples of the other components include, but are not limited to, coupling agents, inorganic fillers, organic fillers, ultraviolet absorbers, antioxidants, light stabilizers, antioxidants, light diffusers, plasticizers, organic pigments, dyes, pigments, lubricants, impact modifiers, metal deactivators, flame retardants, flame retardant assistants, slip aids, reinforcing agents, and mold release agents. The other components may be used singly or in combination of two or more. The content of these other components is not particularly limited, but should be limited to a range in which the base film 1 performs a desired function without losing the expansion (expansion) property and the heat shrinkage property.

< total thickness of substrate film and thickness of resin layers >)

The total thickness of the base film 1 of the present embodiment is not particularly limited, but the lower limit thereof is preferably 60 μm, more preferably 70 μm. On the other hand, the upper limit value is preferably 150. Mu.m, more preferably 120. Mu.m. When the total thickness of the base film 1 is less than 60 μm, for example, the strength may become insufficient for holding the ring frame at the time of dicing. On the other hand, when the total thickness of the base film 1 exceeds 150 μm, for example, the swelling (expanding) property may be poor. In addition, when the substrate film 1 and the adhesive tape 10 for wafer processing are wound in a roll form, a step mark may be generated in the winding core portion.

The thickness of each of the resin layers containing the specific ionomer resin in a content ratio of 80 mass% or more in the base film 1 is not particularly limited, but is preferably 10 μm, more preferably 20 μm, as a lower limit thereof. On the other hand, the upper limit value is preferably 50. Mu.m, more preferably 40. Mu.m. The total thickness of all resin layers containing the specific ionomer resin at a content ratio of 80 mass% or more is not particularly limited, but the lower limit thereof is preferably 65%, more preferably 80%, further preferably 90%, and the upper limit thereof is 100% of the total thickness of the base film 1. In the base film 1 thus adjusted, the mechanical properties exhibited by the appropriate and highly crosslinked structure of the specific ionomer resin are sufficiently reflected, and therefore the tensile stress, the uniform expansibility, and the restoring force upon heating for deformation after stretching of the base film 1 become sufficient. As a result, the die bonding film (adhesive layer) 3 is satisfactorily cut, and the kerf width between individual semiconductor chips can be sufficiently ensured, so that good pick-up performance can be obtained.

In addition, the base film 1 of the present embodiment is preferably produced by laminating and producing a film such that the respective thicknesses of the resin layers containing the specific ionomer resin in the base film 1 at a content ratio of 80 mass% or more are in the range of 10 μm to 50 μm, and the total thickness of the base film 1 is in the range of 60 μm to 150 μm, and in this case, the extrusion flow rate can be controlled without excessively increasing the resin pressure and the engine load in the extruder, as compared with the case of producing a base film 1 having the same thickness by producing a film with a single layer structure, and therefore, the base film is suitable from the viewpoints of film production accuracy and stable film formation.

When the base film 1 is formed by further laminating another resin layer on the first resin layer and the second resin layer, the total thickness of the other resin layers is preferably appropriately adjusted to be in the range of 60 μm to 150 μm in total of the base film 1. The total thickness of the other resin layers is preferably adjusted in a range of, for example, 0.6 μm to 52 μm.

Method for producing substrate film

The method for producing the base film 1 of the present embodiment is not particularly limited, and for example, a T-die coextrusion method or an expansion coextrusion method in which the above-described resin composition for forming the first resin layer and the above-described resin composition for forming the second resin layer are supplied to separate extruders and melted, and the respective melted resin compositions are extruded from 1 die can be used. In the case of producing the base film 1 having a structure of 3 or more layers, separate extruders having the corresponding layers may be used. In addition, a method of extrusion-laminating a second resin layer on a previously-formed first resin layer, a method of extrusion-laminating a second resin layer between 2 previously-formed first resin layers, or the like may also be used. Among these, the T-die coextrusion method is suitable from the viewpoints of uniform expansibility and production efficiency of the base film 1. Since the resin is easily oriented in the expansion coextrusion method, the uniform expansibility may be lowered. In addition, the extrusion lamination method requires that one layer is formed into a film in advance, and thus the production efficiency is deteriorated.

In the T-die coextrusion method, it is desirable to use a T-die coextrusion-roll molding method using a roll (nip roll) having fine irregularities on the surface. When the resin composition is extruded from the T die and sandwiched between a cooling roll and a roll having fine irregularities (roll forming is performed), for example, even if a resin layer containing the specific ionomer resin having a low vicat softening point is disposed as the outermost layer of the base film 1, the irregularities formed on the surface of the base film 1 can ensure the peelability of the resin layer from the roll at the time of film formation of the base film 1 and at the time of manufacturing the adhesive tape for wafer processing, and the anti-blocking property of the base film 1 after film formation or the rolled raw roll of the adhesive tape for wafer processing after processing.

Adhesive layer

The adhesive tape 10 for wafer processing of the present invention comprises: the adhesive layer 2 for holding (temporarily fixing) the semiconductor wafer is provided on the surface of the substrate film 1 on one side. The surface of the adhesive layer 2 of the adhesive tape 10 for wafer processing (the surface opposite to the surface facing the base film 1) may also be provided with a base sheet (release liner) having releasability. As the adhesive for forming the adhesive layer 2, conventionally known adhesive compositions such as acrylic, silicone, polyester, polyvinyl acetate, polyurethane, and rubber can be used. Among these, from the viewpoints of versatility and practical reliability, an active energy ray-curable acrylic adhesive composition which cures and contracts by irradiation with active energy rays such as ultraviolet rays (UV) and thereby reduces adhesion to an adherend is suitably used.

Acrylic pressure-sensitive adhesive composition curable with active energy rays

The active energy ray-curable acrylic adhesive composition typically includes: the adhesive composition (a) containing a photosensitive acrylic adhesive polymer having a carbon-carbon double bond and a functional group (hereinafter, sometimes referred to as "active energy ray-curable acrylic adhesive polymer"), a photopolymerization initiator, and a crosslinking agent reactive with the functional group, or the adhesive composition (B) containing an acrylic adhesive polymer having a functional group, an active energy ray-curable compound, a photopolymerization initiator, and a crosslinking agent reactive with the functional group, are not particularly limited thereto. Among them, from the viewpoint of improving the releasability from the adhesive layer 3 and suppressing the residual glue on the adhesive layer 3, the former type of adhesive composition (a) comprising an active energy ray-curable acrylic adhesive polymer, a photopolymerization initiator, and a crosslinking agent reacting with the functional group is preferable. The functional group referred to herein means a thermally reactive functional group capable of coexisting with a carbon-carbon double bond. Examples of the functional group include an active hydrogen group such as a hydroxyl group, a carboxyl group, and an amino group, and a functional group thermally reacting with an active hydrogen group such as a glycidyl group. The active hydrogen group means a functional group having an element other than carbon, such as nitrogen, oxygen or sulfur, and hydrogen directly bonded thereto.

Adhesive composition (A)

[ acrylic adhesive Polymer having carbon-carbon double bond and functional group ]

The adhesive composition (A) comprises: a photosensitive acrylic adhesive polymer having a carbon-carbon double bond and a functional group, a photopolymerization initiator, and a crosslinking agent that reacts with the functional group. As the acrylic adhesive polymer having a carbon-carbon double bond and a functional group in the adhesive composition (a), a polymer having a carbon-carbon double bond introduced into a molecular side chain is used. The method for producing the acrylic adhesive polymer having a carbon-carbon double bond and a functional group is not particularly limited, and examples thereof include, in general: a method in which a (meth) acrylate is copolymerized with a functional group-containing unsaturated compound to obtain a copolymer, and a compound having a functional group capable of undergoing an addition reaction with the functional group of the copolymer and a carbon-carbon double bond is subjected to an addition reaction.

The copolymer before the addition reaction of the compound having a functional group and a carbon-carbon double bond (hereinafter, sometimes referred to as "functional group-containing copolymer") may specifically be a copolymer comprising an alkyl (meth) acrylate monomer and an active hydrogen group-containing monomer and/or a glycidyl group-containing monomer.

Examples of the alkyl (meth) acrylate monomer include: hexyl (meth) acrylate having 6 to 18 carbon atoms, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, or amyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ethyl (meth) acrylate, methyl (meth) acrylate, or the like, as a monomer having 5 or less carbon atoms.

Examples of the active hydrogen group-containing monomer include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, anhydride group-containing monomers such as maleic anhydride and itaconic anhydride, and amide-based monomers such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-hydroxymethyl propane (meth) acrylamide, N-methoxymethyl (meth) acrylamide, and N-butoxymethyl (meth) acrylamide; amino group-containing monomers such as aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, and t-butylaminoethyl (meth) acrylate. These active hydrogen group-containing monomer components may be used alone or in combination of 2 or more. Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate.

The content of the thermally reactive functional group is not particularly limited, but is preferably in the range of 0.5 mass% to 50 mass% with respect to the total amount of the comonomer components.

Specific examples of the copolymer having a suitable functional group obtained by copolymerizing the above monomers include a binary copolymer of 2-ethylhexyl acrylate and acrylic acid, a binary copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, a ternary copolymer of 2-ethylhexyl acrylate and methacrylic acid and 2-hydroxyethyl acrylate, a binary copolymer of n-butyl acrylate and acrylic acid, a binary copolymer of n-butyl acrylate and 2-hydroxyethyl acrylate, a ternary copolymer of n-butyl acrylate and methacrylic acid and 2-hydroxyethyl acrylate, a ternary copolymer of 2-ethylhexyl acrylate and methyl methacrylate and 2-hydroxyethyl acrylate, a quaternary copolymer of 2-ethylhexyl acrylate and n-butyl acrylate and 2-hydroxyethyl acrylate and methacrylic acid, a quaternary copolymer of 2-ethylhexyl acrylate and methyl methacrylate and 2-hydroxyethyl acrylate, and the like, but the present invention is not limited thereto.

The functional group-containing copolymer may contain other comonomer components as needed for the purpose of cohesive force, heat resistance, and the like. Specific examples of such other comonomer components include cyano-containing monomers such as (meth) acrylonitrile, olefin-based monomers such as ethylene, propylene, isoprene, butadiene and isobutylene, styrene-based monomers such as styrene, α -methylstyrene and vinyltoluene, vinyl ester-based monomers such as vinyl acetate and vinyl propionate, vinyl ether-based monomers such as methyl vinyl ether and ethyl vinyl ether, halogen-containing monomers such as vinyl chloride and vinylidene chloride, alkoxy-containing monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, and monomers having a nitrogen atom ring such as N-vinyl-2-pyrrolidone, N-methyl vinyl pyrrolidone, N-vinyl pyridine, N-vinyl piperidone, N-vinyl pyrimidine, N-vinyl piperazine, N-vinyl pyrazine, N-vinyl pyrrole, N-vinyl imidazole, N-vinyl oxazole, N-vinyl morpholine, N-vinyl caprolactam and N- (meth) acryloylmorpholine. These other comonomer components may be used alone or in combination of 2 or more. The functional group-containing acrylic pressure-sensitive adhesive polymer preferably has a glass transition temperature (Tg) in the range of-70 ℃ to 15 ℃ inclusive, more preferably in the range of-60 ℃ to-10 ℃ inclusive.

The acrylic adhesive polymer having a carbon-carbon double bond and a functional group can be obtained as follows: the copolymer having a functional group is obtained by subjecting a compound having a functional group capable of undergoing an addition reaction with the functional group of the copolymer and a carbon-carbon double bond to an addition reaction. As such a compound having a functional group and a carbon-carbon double bond, for example, in the case of performing an addition reaction on a hydroxyl group located in a side chain of the above copolymer, an isocyanate compound having a (meth) acryloyloxy group such as 2-methacryloyloxyethyl isocyanate, 4-methacryloyloxy n-butyl isocyanate, 2-acryloyloxyethyl isocyanate, m-isopropenyl- α, α -dimethylbenzyl isocyanate, or the like can be used. In addition, in the case of performing an addition reaction on the carboxyl group located in the side chain of the above copolymer, glycidyl (meth) acrylate, 2- (1-aziridinyl) ethyl (meth) acrylate, or the like can be used as the compound. Further, in the case of performing an addition reaction on a glycidyl group located in a side chain of the above copolymer, a (meth) acrylic acid or the like can be used as the compound.

The most suitable method for the addition reaction is from the viewpoints of tracking the easiness of reaction (stability of control) and easiness of technical difficulty: a method of causing an addition reaction of a compound having an isocyanate group capable of causing an addition reaction of a hydroxyl group of a copolymer in a side chain and a carbon-carbon double bond (an isocyanate compound having a (meth) acryloyloxy group).

In the addition reaction, it is preferable that a functional group such as a hydroxyl group, a carboxyl group, or a glycidyl group is previously left in order to crosslink the active energy ray-curable acrylic adhesive polymer by a crosslinking agent such as a polyisocyanate crosslinking agent or an epoxy crosslinking agent described later and to increase the molecular weight. For example, when a copolymer having a hydroxyl group in a side chain is reacted with an isocyanate compound having a (meth) acryloyloxy group, the mixing ratio of the two may be adjusted so that the equivalent ratio [ (NCO)/(OH) ] of the isocyanate group (-NCO) of the isocyanate compound having a (meth) acryloyloxy group to the hydroxyl group (-OH) located in the side chain of the copolymer is less than 1.0. In this way, an acrylic adhesive polymer having a functional group and a carbon-carbon double bond such as a (meth) acryloyloxy group, that is, an active energy ray-curable acrylic adhesive polymer can be obtained.

In the above addition reaction, a polymerization inhibitor is preferably used to maintain the active energy ray reactivity of the carbon-carbon double bond. As such polymerization inhibitor, a quinone polymerization inhibitor such as hydroquinone-monomethyl ether is preferable. The amount of the polymerization inhibitor is not particularly limited, and is preferably in the range of usually 0.01 parts by mass to 0.1 parts by mass relative to the total amount of the functional group-containing copolymer and the active energy ray-reactive compound.

The active energy ray-curable acrylic pressure-sensitive adhesive polymer preferably has a weight average molecular weight Mw in the range of 10 to 200 ten thousand. When the weight average molecular weight Mw of the active energy ray-curable acrylic adhesive polymer is less than 10 ten thousand, it is difficult to obtain a solution of the high-viscosity active energy ray-curable resin composition of several thousands cP to several tens of thousands cP in view of coatability and the like, which is not preferable. In addition, the cohesive force of the adhesive layer 2 before the irradiation of the active energy ray is reduced, and for example, when the semiconductor chip with the die-bonding film 3 is detached from the adhesive layer 2 after the irradiation of the active energy ray, the semiconductor wafer with the die-bonding film 3 may be contaminated. On the other hand, when the weight average molecular weight Mw exceeds 200 ten thousand, there is no particular problem in terms of the properties as an adhesive, but it is difficult to mass-produce an active energy ray-curable acrylic adhesive polymer, for example, the active energy ray-curable acrylic adhesive polymer may gel during synthesis, which is not preferable. The weight average molecular weight Mw of the active energy ray-curable acrylic pressure-sensitive adhesive polymer is more preferably 30 to 150 tens of thousands. The weight average molecular weight Mw herein means a standard polystyrene equivalent measured by gel permeation chromatography.

The carbon-carbon double bond content of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group may be any amount as long as a sufficient effect of reducing adhesive force can be obtained in the adhesive layer 2 after irradiation with active energy rays, and may be different depending on the use conditions such as the irradiation amount of active energy rays, and is not limited to a range of, for example, 0.85 to 1.60 meq/g. When the carbon-carbon double bond content is less than 0.85meq/g, there is a possibility that the effect of reducing the adhesion in the adhesive layer 2 after irradiation with active energy rays becomes small and the pick-up failure of the semiconductor chip with the adhesive layer 3 increases. On the other hand, when the carbon-carbon double bond content exceeds 1.60meq/g, the following problems may occur: the fluidity of the adhesive in the adhesive layer 2 after irradiation with active energy rays becomes insufficient, the gaps between the semiconductor chips after expansion of the dicing die bonding film 20 are not sufficiently spread, and image recognition of the individual semiconductor chips becomes difficult at the time of pickup. In addition, depending on the copolymerization composition of the acrylic adhesive polymer, polymerization or reaction may be easily performed during synthesis, and gelation may be easily performed, which may make synthesis difficult. When the carbon-carbon double bond content of the active energy ray-curable acrylic adhesive polymer is confirmed, the carbon-carbon double bond content can be calculated by measuring the iodine value of the active energy ray-curable acrylic adhesive polymer.

[ photopolymerization initiator ]

As described above, the active energy ray-curable acrylic adhesive composition (a)) contains a photopolymerization initiator that generates radicals by irradiation with active energy rays. The photopolymerization initiator generates radicals upon irradiation of active energy rays to the adhesive layer when the adherend is debonded, and initiates a crosslinking reaction of carbon-carbon double bonds of the active energy ray-curable acrylic adhesive polymer in the adhesive layer 2. As a result, the adhesive layer is further cured and shrunk by irradiation with active energy rays, and the adhesion to the adherend is reduced. The photopolymerization initiator is preferably a compound that generates a radical active species by ultraviolet rays or the like, and examples thereof include an alkylbenzeneketone radical polymerization initiator, an acylphosphine oxide radical polymerization initiator, an oxime ester radical polymerization initiator, and the like. These photopolymerization initiators may be used alone or in combination of 2 or more.

Examples of the alkyl benzophenone-based radical polymerization initiator include benzilmethyl ketal-based radical polymerization initiators, α -hydroxyalkylbenzophenone-based radical polymerization initiators, and α -aminoalkylbenzophenone-based radical polymerization initiators.

Specific examples of the benzilmethyl ketal-based radical polymerization initiator include 2,2' -dimethoxy-1, 2-diphenylethan-1-one (for example, trade names: omnirad651, manufactured by IGM Resins B.V. Co.) and the like. Specific examples of the α -hydroxyalkylphenone radical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropane-1-one (trade name: omnirad1173, manufactured by IGM Resins B.V. Co.), 1-hydroxycyclohexylphenyl ketone (trade name: omnirad184, manufactured by IGM Resins B.V. Co.), 1- [4- (2-hydroxyethoxy) phenyl ] -2-hydroxy-2-methyl-1-propan-1-one (trade name: omnirad2959, manufactured by IGM Resins B.V. Co.), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropanoyl) benzyl ] phenyl } -2-methylpropan-1-one (trade name: omnirad127, manufactured by IGM Resins B.V. Co.), and the like. Specific examples of the α -aminoalkylbenzophenone-based radical polymerization initiator include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (trade name: omnirad907, manufactured by IGM Resins b.v. company), 2-benzyl-2- (dimethylamino) -4' -morpholinophenone (trade name: omnirad369, manufactured by IGM Resins b.v. company), 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (trade name: omnirad379EG, manufactured by IGM Resins b.v. company), and the like.

Specific examples of the acylphosphine oxide-based radical polymerization initiator include 2,4, 6-trimethylbenzoyl diphenyl phosphine oxide (trade name: omnirad TPO, manufactured by IGM Resins B.V. Co.), bis (2, 4, 6-trimethylbenzoyl) phenyl phosphine oxide (trade name: omnirad819, manufactured by IGM Resins B.V. Co.), and the like.

Examples of the oxime ester-based radical polymerization initiator include 1, 2-octanedione, 1- [4- (phenylthio) phenyl ] -,2- (O-benzoyloxime) (trade name: omniradOXE-01, manufactured by IGM Resins B.V. Co.) and the like.

The amount of the photopolymerization initiator to be added is preferably in the range of 0.1 to 10.0 parts by mass based on 100 parts by mass of the solid content of the active energy ray-curable acrylic adhesive polymer. When the amount of the photopolymerization initiator to be added is less than 0.1 parts by mass, since the photoreactivity to the active energy ray is insufficient, the photo radical crosslinking reaction of the acrylic adhesive polymer is not sufficiently caused even by irradiation of the active energy ray, curing and shrinkage of the adhesive become insufficient, and as a result, there is a possibility that the effect of reducing the adhesive force in the adhesive layer 2 after irradiation of the active energy ray becomes small, and pickup failure of the semiconductor chip increases. On the other hand, when the amount of the photopolymerization initiator added exceeds 10.0 parts by mass, the effect is saturated, and it is not preferable from the viewpoint of economy. In addition, depending on the type of photopolymerization initiator, the adhesive layer 2 may turn yellow, resulting in poor appearance.

As a sensitizer for such a photopolymerization initiator, a compound such as dimethylaminoethyl methacrylate or isoamyl 4-dimethylaminobenzoate may be added to the adhesive.

[ Cross-linking agent ]

As described above, in order to increase the molecular weight of the active energy ray-curable acrylic pressure-sensitive adhesive polymer, the active energy ray-curable acrylic pressure-sensitive adhesive composition (a)) further contains a crosslinking agent. The crosslinking agent is not particularly limited, and a known crosslinking agent having a functional group capable of reacting with a hydroxyl group, a carboxyl group, a glycidyl group, or the like, which is a functional group of the active energy ray-curable acrylic adhesive polymer, can be used. Specifically, examples thereof include polyisocyanate-based crosslinkers, epoxy-based crosslinkers, aziridine-based crosslinkers, melamine-resin-based crosslinkers, urea-resin-based crosslinkers, acid anhydride compound-based crosslinkers, polyamine-based crosslinkers, and carboxyl-containing polymer-based crosslinkers. Among these, a polyisocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferably used from the viewpoints of reactivity and versatility. These crosslinking agents may be used singly or in combination of 2 or more. The amount of the crosslinking agent to be blended is preferably in the range of 0.01 to 15 parts by mass based on 100 parts by mass of the solid content of the active energy ray-curable acrylic adhesive polymer.

Examples of the polyisocyanate-based crosslinking agent include a polyisocyanate compound having an isocyanurate ring, a polyisocyanate compound adduct obtained by reacting trimethylolpropane with hexamethylene diisocyanate, a polyisocyanate compound adduct obtained by reacting trimethylolpropane with toluene diisocyanate, a polyisocyanate compound adduct obtained by reacting trimethylolpropane with xylylene diisocyanate, and a polyisocyanate compound adduct obtained by reacting trimethylolpropane with isophorone diisocyanate. These may be used in 1 kind or in combination of 2 or more kinds.

Examples of the epoxy-based crosslinking agent include bisphenol a-epichlorohydrin-based epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycidyl polyglycidyl ether, 1,3 '-bis (N, N-diglycidyl aminomethyl) cyclohexane, N' -tetraglycidyl m-xylylenediamine, and the like. These may be used in 1 kind or in combination of 2 or more kinds.

The aging conditions for reacting the crosslinking agent with the functional group-containing active energy ray-curable acrylic adhesive polymer after the adhesive layer 2 is formed from the active energy ray-curable resin composition (adhesive composition (a)) are not particularly limited, and may be appropriately set, for example, in a range of from 23 to 80 ℃ and a range of from 24 to 168 hours.

[ others ]

The active energy ray-curable acrylic pressure-sensitive adhesive composition (a)) may be added with other additives such as a polyfunctional acrylic monomer, a polyfunctional acrylic oligomer, a tackifier, a filler, an antioxidant, a colorant, a flame retardant, an antistatic agent, a surfactant, a silane coupling agent, and a leveling agent, as required, within a range that does not impair the effects of the present invention.

Adhesive composition (B)

[ acrylic adhesive Polymer having functional group ]

The adhesive composition (B) contains: an acrylic adhesive polymer having a functional group, an active energy ray-curable compound, a photopolymerization initiator, and a crosslinking agent that reacts with the functional group. As the acrylic adhesive polymer having a functional group of the adhesive composition (B), the same ones as exemplified as the acrylic adhesive polymer having a functional group in the description of the active energy ray-curable acrylic adhesive composition (a)) can be used.

[ active energy ray-curable Compound ]

As the active energy ray-curable compound of the adhesive composition (B), for example, a low molecular weight compound capable of three-dimensionally reticulating by irradiation with active energy rays and having at least 2 or more carbon-carbon double bonds in a molecule is widely used. Specific examples of such low molecular weight compounds include esters of (meth) acrylic acid with polyhydric alcohols, such as trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, tetraethyleneglycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and the like; and isocyanurates such as 2-propenyl-di-3-butenyl cyanurate, 2-hydroxyethyl bis (2-acryloyloxyethyl) isocyanurate, and tris (2-methacryloyloxyethyl) isocyanurate, isocyanurate compounds, and the like. These active energy ray-curable low molecular weight compounds may be used alone or in combination of 2 or more.

In addition, as the active energy ray-curable compound, in addition to the low molecular weight compound described above, an active energy ray-curable oligomer such as an epoxy acrylate-based oligomer, a urethane acrylate-based oligomer, or a polyester acrylate-based oligomer may be used. Epoxy acrylates are synthesized by the addition reaction of an epoxy compound with (meth) acrylic acid. Urethane acrylates are synthesized, for example, as follows: the addition reaction product of a polyol and a polyisocyanate is synthesized by reacting an isocyanate group remaining at the terminal with a hydroxyl group-containing (meth) acrylate to introduce a (meth) acryloyl group at the molecular terminal. Polyester acrylates are synthesized by the reaction of polyester polyols with (meth) acrylic acid. The active energy ray-curable oligomer is preferably a polymer having 3 or more carbon-carbon double bonds in the molecule, from the viewpoint of the effect of reducing the adhesive force of the adhesive layer 2 after irradiation with active energy rays. These active energy ray-curable oligomers may be used alone or in combination of 2 or more.

The weight average molecular weight Mw of the active energy ray-curable oligomer is not particularly limited, but is preferably in the range of 100 to 30,000, and is more preferably in the range of 500 to 6,000 from the viewpoint of suppressing both the contamination of the semiconductor chip and the effect of reducing the adhesive force of the adhesive layer 2 after irradiation with active energy rays.

The content of the active energy ray-curable compound is in the range of 5 parts by mass to 500 parts by mass, preferably 50 parts by mass to 180 parts by mass, based on 100 parts by mass of the acrylic adhesive polymer having a functional group. When the content of the active energy ray-curable compound is within the above range, the adhesive force of the adhesive layer 2 can be appropriately reduced after irradiation with active energy rays, and the semiconductor chip is not broken, and the pickup is facilitated.

[ photopolymerization initiator ]

The active energy ray-curable acrylic pressure-sensitive adhesive composition (B)) contains a photopolymerization initiator that generates radicals by irradiation with active energy rays. As the photopolymerization initiator, the same initiator as exemplified in the description of the active energy ray-curable acrylic adhesive composition (a)) can be used. The same applies to the amount of photopolymerization initiator added.

[ Cross-linking agent ]

In order to increase the molecular weight of the acrylic adhesive polymer having a functional group, the active energy ray-curable acrylic adhesive composition (B)) further contains a crosslinking agent. As the crosslinking agent, the same ones as exemplified as the crosslinking agent in the description of the active energy ray-curable acrylic adhesive composition (a)) can be used. The same applies to the amount of the crosslinking agent to be blended and the aging conditions for reacting the crosslinking agent with the functional acrylic adhesive polymer.

[ others ]

The active energy ray-curable acrylic pressure-sensitive adhesive composition (B)) may be optionally added with other additives such as tackifiers, fillers, antioxidants, colorants, flame retardants, antistatic agents, surfactants, silane coupling agents, leveling agents, and the like, within a range not impairing the effects of the present invention.

< thickness of adhesive layer >

The thickness of the adhesive layer 2 of the adhesive tape 10 for wafer processing of the present invention is not particularly limited, but is preferably in the range of 5 μm to 50 μm, more preferably in the range of 6 μm to 20 μm, and particularly preferably in the range of 7 μm to 15 μm. When the thickness of the adhesive layer 2 is less than 5 μm, the adhesive force of the adhesive tape 10 for wafer processing may be excessively reduced. In this case, in the cold expansion step, the die bonding film 3 tends to float from the adhesive layer 2, and the yield of semiconductor chips is lowered. In addition, when used as a dicing die bonding film, poor adhesion between the adhesive layer 2 and the die bonding film 3 may occur. On the other hand, if the thickness of the adhesive layer 2 exceeds 50 μm, internal stress generated when the adhesive tape 10 for wafer processing is cold-expanded may become difficult to be transmitted as external stress to the semiconductor wafer with the die-bonding film 3, and in this case, the dicing yield of the semiconductor chip with the die-bonding film 3 may be lowered in the dicing step. In addition, the adhesion to the die-bonding film 3 is improved, and it is not preferable in practice from the viewpoint of economy after irradiation with active energy rays.

Anchor coating

The adhesive tape 10 for wafer processing according to the present embodiment may be provided with an anchor coat layer matching the composition of the base film 1 between the base film 1 and the adhesive layer 2, depending on the conditions for manufacturing the adhesive tape 10 for wafer processing, the conditions for using the adhesive tape 10 for wafer processing after manufacturing, and the like, within a range that does not impair the effects of the present invention. By providing the anchor coat layer, the adhesion between the base film 1 and the adhesive layer 2 is improved.

Release liner

On the surface side (one surface side) of the adhesive layer 2 opposite to the base film 1, a release liner may be provided as needed. Examples of the release liner include, but are not limited to, synthetic resins such as polyethylene, polypropylene and polyethylene terephthalate, and papers. In order to improve the releasability of the adhesive layer 2, the surface of the release liner may be subjected to a release treatment using a silicone release treatment agent, a long-chain alkyl release treatment agent, a fluorine release treatment agent, or the like. The thickness of the release liner is not particularly limited, and a release liner in the range of 10 μm to 200 μm may be suitably used.

(method for producing an adhesive tape for wafer processing)

Fig. 6 is a flowchart illustrating a method for manufacturing the adhesive tape 10 for wafer processing. First, a release liner is prepared (step S101: a release liner preparation step). Next, a coating solution for the adhesive layer 2 (adhesive layer forming coating solution) is prepared as a material for forming the adhesive layer 2 (step S102: a coating solution preparing step). The coating solution can be produced, for example, by uniformly mixing and stirring the acrylic adhesive polymer, which is a constituent of the adhesive layer 2, the crosslinking agent, and the diluting solvent. As the solvent, for example, general-purpose organic solvents such as toluene and ethyl acetate can be used.

Then, the adhesive layer 2 having a predetermined thickness is formed by applying the coating solution for the adhesive layer 2 produced in step S102 to the release treated surface of the release liner and drying the same (step S103: adhesive layer forming step). The coating method is not particularly limited, and for example, a die coater, a half-wheel coater (registered trademark), a gravure coater, a roll coater, a reverse coater, or the like may be used for coating. The drying conditions are not particularly limited, and are preferably, for example, those in which the drying temperature is 80 ℃ to 150 ℃ and the drying time is 0.5 minutes to 5 minutes. Next, the base film 1 is prepared (step S104: base film preparation step). Then, the base film 1 is bonded to the adhesive layer 2 formed on the release liner (step S105: base film bonding step). Finally, the formed adhesive layer 2 is aged for 72 hours at, for example, 40℃to react the acrylic adhesive polymer with the crosslinking agent, thereby crosslinking and curing the same (step S106: a heat curing step). Through the above steps, the adhesive tape 10 for wafer processing including the adhesive layer 2 and the release liner in this order from the substrate film side on the substrate film 1 can be manufactured. In the present invention, a laminate including a release liner on the adhesive layer 2 may be referred to as an adhesive tape 10 for wafer processing.

As a method of forming the adhesive layer 2 on the base film 1, a method of applying a coating solution for the adhesive layer 2 on a release liner and drying the same, and then bonding the base film 1 on the adhesive layer 2 has been exemplified, but a method of directly applying a coating solution for the adhesive layer 2 on the base film 1 and drying the same may be adopted. The former method is suitably used from the viewpoint of stable production.

The adhesive tape 10 for wafer processing according to the present embodiment may be in a form of being wound into a roll, or in a form of laminating sheets having a wide width. The wafer processing adhesive tape 10 of these forms may be cut into a sheet or tape form having a predetermined size.

(dicing die bonding film)

According to the second aspect of the present invention, in the semiconductor manufacturing process, the adhesive tape 10 for wafer processing according to the present embodiment may be used as a so-called dicing die-bonding film 20 in which the die-bonding film (adhesive layer) 3 is laminated and adhered to the adhesive layer 2 of the adhesive tape 10 for wafer processing in a releasable manner. The die bonding film (adhesive layer) 3 is a film for bonding and connecting semiconductor chips diced and singulated by cold expansion to a lead frame and a wiring board (supporting board). In addition, when the semiconductor chips are stacked, the adhesive layer functions as an adhesive layer between the semiconductor chips. In this case, the semiconductor chip of the first stage is bonded to the wiring board for mounting the semiconductor chip on which the terminal is formed through the die bonding film (adhesive layer) 3, and the semiconductor chip of the second stage is further bonded through the die bonding film (adhesive layer) 3 on the semiconductor chip of the first stage. The connection terminals of the semiconductor chip of the first stage and the semiconductor chip of the second stage are electrically connected to external connection terminals via leads, but the leads for the semiconductor chip of the first stage are buried in the die bonding film (adhesive layer) 3 at the time of crimping (die bonding), that is, the leads are buried in the die bonding film (adhesive layer) 3. Hereinafter, an example of the die bonding film (adhesive layer) 3 when the adhesive tape (dicing tape) 10 for wafer processing according to the present embodiment is used as the dicing die bonding film 20 will be described, but the present invention is not limited to this example.

Chip bonding film (adhesive layer)

The die bonding film (adhesive layer) 3 is a layer formed of a thermosetting adhesive composition cured by heat. The adhesive composition is not particularly limited, and conventionally known adhesive compositions can be used. Examples of preferred embodiments of the adhesive composition include thermosetting adhesive compositions obtained by adding a curing accelerator, an inorganic filler, a silane coupling agent, and the like to a resin composition containing a glycidyl group-containing (meth) acrylate copolymer as a thermoplastic resin, an epoxy resin as a thermosetting resin, and a phenolic resin as a curing agent for the epoxy resin. The die bonding film (adhesive layer) 3 formed from such a thermosetting adhesive composition has the following characteristics: the semiconductor chip/support substrate and the semiconductor chip/semiconductor chip are excellent in adhesion, and can be provided with electrode embedding property, lead embedding property, and the like, and the bonding can be performed at a low temperature in the die bonding step, and excellent curing can be obtained in a short time, and the semiconductor chip/support substrate and the semiconductor chip/semiconductor chip are preferably molded with a sealant and then have excellent characteristics such as reliability.

The general-purpose die bonding film used in a state where the wire is not embedded in the adhesive layer and the wire-embedded die bonding film used in a state where the wire is embedded in the adhesive layer are almost the same as the types of materials constituting the adhesive composition thereof, but the general-purpose die bonding film or the wire-embedded die bonding film can be customized by changing the blending ratio of the materials used, the physical properties, characteristics, and the like of the materials according to the respective purposes. In addition, when there is no problem in reliability as a final semiconductor device, a wire-embedded die bonding film may be used as a general-purpose die bonding film. That is, the wire-embedded die bonding film is not limited to the wire embedding application, and can be used in the same way for bonding a semiconductor chip to a substrate having irregularities due to wiring or the like, a metal substrate such as a lead frame, or the like.

Adhesive composition for general chip bonding film

First, an example of an adhesive composition for a general-purpose die-bonding film will be described, but the present invention is not limited to this example. As an index of fluidity at the time of die bonding of the die bonding film 3 formed of the adhesive composition, for example, shear viscosity characteristics at 80 ℃ may be mentioned, and in the case of a general-purpose die bonding film, generally, the shear viscosity at 80 ℃ exhibits a value in the range of 20,000pa·s to 40,000pa·s, preferably 25,000pa·s to 35,000pa·s. The shear viscosity at 80℃is a value measured by the following method. The die bonding film (adhesive layer) 3 was laminated in a plurality of sheets at 70℃so that the total thickness was 200 to 210. Mu.m. Next, the laminate was die-cut into a size of 10mm×10mm in the thickness direction to obtain a measurement sample. Next, a circular aluminum plate jig having a diameter of 8mm was assembled using a dynamic viscoelasticity device ARES (made by rheologic technology FE (Rheometric Scientific F.E.), and then the measurement sample was placed. The measurement sample was subjected to a deformation of 5% at 35℃and a shear viscosity was measured while heating the measurement sample at a heating rate of 5℃per minute, to determine the value of the shear viscosity at 80 ℃.

As an example of a preferable form of the adhesive composition for a general-purpose die bonding film, the following adhesive composition can be given: when the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin, which are resin components of the adhesive composition, is 100 parts by mass, the curing accelerator is contained in a range of 52 to 90 parts by mass, the epoxy resin is contained in a range of 5 to 25 parts by mass, the phenolic resin is contained in a range of 5 to 23 parts by mass, and the total amount of the resin components is adjusted to 100 parts by mass, the curing accelerator is contained in a range of 0.1 to 0.3 parts by mass, and the inorganic filler is contained in a range of 5 to 20 parts by mass, based on 100 parts by mass of the total amount of the epoxy resin and the phenolic resin, and the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin is contained in a range of 100 parts by mass.

[ glycidyl group-containing (meth) acrylate copolymer ]

The glycidyl group-containing (meth) acrylate copolymer preferably contains, as the copolymer unit, at least an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms and a glycidyl (meth) acrylate. The copolymer unit of the glycidyl (meth) acrylate is preferably contained in a range of 0.5 mass% to 6.0 mass%, more preferably in a range of 2.0 mass% to 4.0 mass%, in terms of ensuring an appropriate adhesive strength, in the total amount of the glycidyl (meth) acrylate-containing copolymer. In addition, from the viewpoint of adjusting the glass transition temperature (Tg), the glycidyl (meth) acrylate-containing copolymer may contain other monomers such as styrene and acrylonitrile as a copolymer unit as required.

The glass transition temperature (Tg) of the glycidyl group-containing (meth) acrylate copolymer is preferably in the range of-50℃to 30℃and more preferably in the range of-10℃to 30℃from the viewpoint of improving the handleability (tackiness inhibition) as a die-bonding film. In order to obtain such a glass transition temperature of the glycidyl group-containing (meth) acrylate copolymer, it is preferable to use ethyl (meth) acrylate and/or butyl (meth) acrylate as the alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms.

The weight average molecular weight Mw of the glycidyl group-containing (meth) acrylate copolymer is preferably in the range of 50 to 200 ten thousand, more preferably in the range of 70 to 100 ten thousand. When the weight average molecular weight Mw is within the above range, the adhesion, heat resistance and fluidity are easily improved. The weight average molecular weight Mw herein means a standard polystyrene equivalent measured by gel permeation chromatography.

The content of the glycidyl (meth) acrylate-containing copolymer in the die-bonding film (adhesive layer) 3 is preferably in the range of 52 mass% to 90 mass%, more preferably 60 mass% to 80 mass%, based on 100 parts by mass of the total amount of the glycidyl (meth) acrylate-containing copolymer, an epoxy resin and a phenolic resin described later, which are resin components in the adhesive composition.

[ epoxy resin ]

Examples of the epoxy resin include, but are not particularly limited to, bisphenol a type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phenol novolac type epoxy resins, alkylphenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol a novolac type epoxy resins, diglycidyl etherate of diphenol, diglycidyl etherate of naphthalene glycol, diglycidyl etherate of phenols, diglycidyl etherate of alcohols, and difunctional epoxy resins such as alkyl substitutes, halides, and hydrides thereof, novolac type epoxy resins, and the like. In addition, other epoxy resins generally known, such as multifunctional epoxy resins and heterocyclic epoxy resins, may be used. These may be used alone or in combination of 2 or more.

The softening point of the epoxy resin is preferably in the range of 70 ℃ to 130 ℃ from the viewpoint of adhesion and heat resistance. In addition, the epoxy equivalent of the epoxy resin is preferably in the range of 100 to 300 from the viewpoint of sufficiently proceeding the curing reaction with the phenolic resin described later.

The content of the epoxy resin in the die-bonding film (adhesive layer) 3 is preferably in the range of 5 mass% to 25 mass%, more preferably in the range of 10 mass% to 20 mass% when the total amount of the glycidyl (meth) acrylate-containing copolymer, the epoxy resin, and the phenolic resin to be described later in the adhesive composition is 100 parts by mass, from the viewpoint that the function as a thermosetting adhesive is properly exhibited in the die-bonding film (adhesive layer) 3.

[ phenolic resin: curing agent for epoxy resin

The curing agent for the epoxy resin is not particularly limited, and examples thereof include phenol resins obtainable by reacting a phenol compound with a xylylene compound as a 2-valent linking group in the absence of a catalyst or an acid catalyst. Examples of the phenolic resin include novolak type phenolic resin, resol type phenolic resin (resol type phenolic resin), and polyhydroxystyrene such as poly-p-hydroxystyrene. Examples of the novolak type phenol resin include phenol novolak resins, phenol aralkyl resins, cresol novolak resins, t-butylphenol novolak resins, and nonylphenol novolak resins. These phenolic resins may be used alone or in combination of 2 or more. Among these phenolic resins, phenol novolac resins and phenol aralkyl resins are preferably used because they tend to improve the connection reliability of the die bonding film (adhesive layer) 3.

The softening point of the phenolic resin is preferably in the range of 70 ℃ to 90 ℃ from the viewpoint of adhesion and heat resistance. In addition, the hydroxyl equivalent of the phenolic resin is preferably in the range of 100 to 200 from the viewpoint of sufficiently proceeding the curing reaction with the epoxy resin.

From the viewpoint of sufficiently allowing the curing reaction of the epoxy resin and the phenolic resin in the thermosetting resin composition, the hydroxyl groups in the phenolic resin are preferably blended in an amount within a range of preferably 0.5 to 2.0 equivalents, more preferably 0.8 to 1.2 equivalents, relative to 1 equivalent of the epoxy groups in the total epoxy resin components. The content of the phenolic resin is preferably in the range of 5 mass% to 23 mass% based on 100 parts by mass of the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin, which is a resin component in the adhesive composition, because the functional group equivalent of each resin depends on the functional group equivalent.

[ curing accelerator ]

In the thermosetting resin composition, a curing accelerator such as a tertiary amine, an imidazole, a quaternary ammonium salt, or the like may be added as necessary. Specific examples of such a curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate, and these may be used alone or in combination of 2 or more. The amount of the curing accelerator is preferably in the range of 0.1 to 0.3 parts by mass based on 100 parts by mass of the total of the epoxy resin and the phenolic resin.

[ inorganic filler ]

Further, in the thermosetting resin composition, an inorganic filler may be added as needed from the viewpoint of controlling the fluidity of the die bonding film (adhesive layer) 3 and improving the elastic modulus. Examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica, amorphous silica, and the like, and 1 or 2 or more of these may be used in combination. Among these, crystalline silica, amorphous silica, and the like are suitably used from the viewpoint of versatility. Specifically, for example, AEROSIL (registered trademark: ultrafine dry silica) having an average particle diameter of nanometer size is suitably used. The content of the inorganic filler in the die bonding film (adhesive layer) 3 is preferably in the range of 5 mass% to 20 mass% based on 100 parts by mass of the total amount of the glycidyl (meth) acrylate copolymer, the epoxy resin, and the phenolic resin as the resin component.

[ silane coupling agent ]

Further, in the thermosetting resin composition, a silane coupling agent may be added as needed from the viewpoint of improving the adhesion to an adherend. Examples of the silane coupling agent include beta- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, gamma-glycidoxypropyl trimethoxysilane and gamma-glycidoxypropyl methyldiethoxysilane, and 1 or 2 or more of these may be used in combination. The amount of the silane coupling agent to be added is preferably in the range of 1.0 to 7.0 parts by mass based on 100 parts by mass of the total of the epoxy resin and the phenolic resin.

[ others ]

Further, the thermosetting resin composition may contain a flame retardant, an ion scavenger, or the like as long as the function as a die-bonding film is not impaired. Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins. Examples of the ion scavenger include hydrotalcite, bismuth hydroxide, antimony hydroxide, zirconium phosphate of a specific structure, magnesium silicate, aluminum silicate, triazole-based compounds, tetrazole-based compounds, bipyridyl-based compounds, and the like.

Adhesive composition for wire-embedded die bonding film

Next, an example of an adhesive composition for a lead-embedded die bonding film will be described, but the adhesive composition is not particularly limited to this example. As an index of fluidity at the time of die bonding of the die bonding film 3 formed of the adhesive composition, for example, a shear viscosity characteristic at 80 ℃ may be mentioned, and in the case of embedding the lead into the die bonding film, in general, the shear viscosity at 80 ℃ may be in a range of 200pa·s to 11,000pa·s, preferably in a range of 2,000pa·s to 7,000pa·s.

As an example of a preferable form of the adhesive composition for a lead-embedded die bonding film, the following adhesive composition can be given: when the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin, which are resin components of the adhesive composition, is 100 parts by mass, the adhesive composition comprises (a) the glycidyl group-containing (meth) acrylate copolymer in a range of 17 to 51 parts by mass, the epoxy resin in a range of 30 to 64 parts by mass, the phenolic resin in a range of 19 to 53 parts by mass, and the total amount of the resin components is 100 parts by mass, (b) the curing accelerator in a range of 0.01 to 0.07 parts by mass relative to 100 parts by mass of the total amount of the epoxy resin and the phenolic resin, and (c) the inorganic filler in a range of 10 to 80 parts by mass relative to 100 parts by mass of the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin.

[ glycidyl group-containing (meth) acrylate copolymer ]

The glycidyl group-containing (meth) acrylate copolymer preferably contains, as the copolymer unit, at least an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms and a glycidyl (meth) acrylate. In the case of a wire-embedded die-bonding film, it is desirable to use a glycidyl (meth) acrylate copolymer (a) having a high copolymer unit ratio of glycidyl (meth) acrylate and a low molecular weight and a glycidyl (meth) acrylate copolymer (B) having a low copolymer unit ratio of glycidyl (meth) acrylate and a high molecular weight in combination, because it is necessary to achieve both of improvement of fluidity at die bonding and securing of adhesive strength after curing, and in combination, the component (a) of the former is preferably contained in a predetermined amount or more.

Specifically, the glycidyl (meth) acrylate-containing copolymer in the adhesive composition for a wire-embedded die bonding film is preferably formed from a mixture of "a glycidyl (meth) acrylate-containing copolymer (a) having a glass transition temperature (Tg) of from-50 ℃ to 30 ℃ and a weight average molecular weight Mw of from 10 to 40 ten thousand" and "a glycidyl (meth) acrylate-containing copolymer (B) having a glass transition temperature (Tg) of from-50 ℃ to 30 ℃ and a weight average molecular weight Mw of from 50 to 90 ten thousand, wherein the glycidyl (meth) acrylate-containing copolymer is preferably contained in a range of from 1.0 to 7.0 mass% of the total glycidyl (meth) acrylate-containing copolymer, and the glycidyl (meth) acrylate-containing copolymer is preferably contained in a range of from-50 to 30 ℃ in a range of from 5.0 mass% to 15.0 mass% of the total glycidyl (meth) acrylate-containing copolymer. The weight average molecular weight Mw herein means a standard polystyrene equivalent measured by gel permeation chromatography.

The content of the glycidyl (meth) acrylate-containing copolymer (a) is preferably in a range of 60 mass% to 90 mass% of the total amount of the glycidyl (meth) acrylate-containing copolymer ((a) and (B) combined). In addition, from the viewpoint of adjusting the glass transition temperature (Tg), the glycidyl (meth) acrylate-containing copolymer may contain other monomers such as styrene and acrylonitrile as a copolymer unit as required.

The glass transition temperature (Tg) of the whole glycidyl group-containing (meth) acrylate copolymer is preferably in the range of-50℃to 30℃and more preferably in the range of-10℃to 30℃from the viewpoint of improving the handleability (tackiness inhibition) as a die-bonding film. In order to obtain such a glass transition temperature of the glycidyl group-containing (meth) acrylate copolymer, ethyl (meth) acrylate and/or butyl (meth) acrylate are preferably used as the alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms.

The content ratio of the total amount of the glycidyl group-containing (meth) acrylate copolymer ((a) and (B)) in the lead embedded die bonding film (adhesive layer) 3 is preferably 17 to 51 mass%, more preferably 20 to 45 mass%, in terms of fluidity at die bonding and adhesive strength after curing, when the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin and the phenolic resin to be described later, in the adhesive composition is 100 parts by mass based on the total amount of the adhesive composition.

[ epoxy resin ]

The epoxy resin is not particularly limited, and the same materials as those exemplified as the epoxy resin for the adhesive composition for a general-purpose die-bonding film can be used. These may be used alone or in combination of 2 or more, and in the case of embedding the leads into the die bonding film, it is necessary to secure the adhesive strength and suppress the occurrence of voids in the adhesive surface and to impart good embeddability to the leads, so that it is preferable to use 2 or more epoxy resins in combination in terms of controlling the fluidity and elastic modulus thereof.

A preferable form of the epoxy resin used for the wire-embedded die bonding film (adhesive layer) 3 is an epoxy resin composed of a mixture of an epoxy resin (C) which is liquid at ordinary temperature and an epoxy resin (D) having a softening point of 98 ℃ or less, preferably 85 ℃ or less. The content of the epoxy resin (C) which is liquid at normal temperature is preferably 15 mass% to 75 mass% of the total amount of the epoxy resins ((C) and (D) in total), and more preferably 30 mass% to 50 mass%. The epoxy equivalent of the epoxy resin is preferably in the range of 100 to 300 from the viewpoint of sufficiently proceeding the curing reaction with the phenolic resin to be described later.

The content of the epoxy resin in the die-bonding film (adhesive layer) 3 is preferably in the range of 30 mass% to 64 mass%, more preferably in the range of 35 mass% to 50 mass%, from the viewpoint of properly exhibiting the function as a thermosetting adhesive in the die-bonding film (adhesive layer) 3, when the total amount of the glycidyl (meth) acrylate-containing copolymer, the epoxy resin, and the phenolic resin to be described later in the adhesive composition is 100 parts by mass.

[ phenolic resin: curing agent for epoxy resin

The curing agent for the epoxy resin is not particularly limited, and the same materials as exemplified for the phenolic resin used for the adhesive composition for a general-purpose die-bonding film can be used. From the viewpoints of adhesion and fluidity, the softening point of the phenolic resin is preferably in the range of 70 ℃ to 115 ℃. In addition, the hydroxyl equivalent of the phenolic resin is preferably in the range of 100 to 200 from the viewpoint of sufficiently proceeding the curing reaction with the epoxy resin.

From the viewpoint of sufficiently conducting the curing reaction between the epoxy resin and the phenolic resin in the thermosetting resin composition, the hydroxyl groups in the phenolic resin component are preferably 0.5 to 2.0 equivalents relative to 1 equivalent of the epoxy groups in the total epoxy resin component, and more preferably in an amount in the range of 0.6 to 1.0 equivalent from the viewpoint of satisfying both fluidity at the time of bonding to a chip. The content of the phenolic resin is preferably in the range of 19 mass% to 53 mass% based on 100 parts by mass of the total amount of the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin, which is a resin component in the adhesive composition, because the functional group equivalent of each resin is not dependent on the total amount of the functional groups.

[ curing accelerator ]

In the thermosetting resin composition, a curing accelerator such as a tertiary amine, an imidazole, a quaternary ammonium salt, or the like may be added as necessary. As such a curing accelerator, the same materials as exemplified as the curing accelerator for the adhesive composition for a general-purpose die-bonding film can be used in the same manner. The amount of the curing accelerator is preferably in the range of 0.01 to 0.07 parts by mass based on 100 parts by mass of the total of the epoxy resin and the phenolic resin from the viewpoint of suppressing occurrence of voids in the adhesive surface.

[ inorganic filler ]

Further, the thermosetting resin composition may be added with an inorganic filler as needed from the viewpoints of improving the handleability of the die bonding film (adhesive layer) 3, adjusting the fluidity at the time of die bonding, imparting thixotropic properties, improving the adhesive strength, and the like. As the inorganic filler, the same materials as exemplified as the inorganic filler for the adhesive composition for a general-purpose die-bonding film can be similarly used, and among these, silica filler is suitably used from the viewpoint of versatility. The content of the inorganic filler in the die bonding film (adhesive layer) 3 is preferably in the range of 10 mass% to 80 mass%, more preferably 15 mass% to 50 mass%, from the viewpoints of fluidity at die bonding, releasability at cold expansion, and adhesive strength, when the total amount of the resin component, that is, the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, and the phenolic resin, is 100 parts by mass based on the total amount.

In order to improve the separability of the die bonding film (adhesive layer) 3 upon cold expansion and to sufficiently exhibit the adhesive force after curing, it is preferable to mix 2 or more kinds of inorganic fillers having different average particle diameters. Specifically, it is preferable to use an inorganic filler having an average particle diameter of 0.1 μm to 5 μm as a main inorganic filler component in an amount of 80 mass% or more based on the total mass of the inorganic filler. In the case where it is necessary to suppress foaming of the adhesive layer 3 and to improve the adhesive strength after curing in the semiconductor chip manufacturing process due to excessive increase in fluidity of the die attach film (adhesive layer) 3, the inorganic filler having an average particle diameter of less than 0.1 μm may be used in combination with the main inorganic filler component in an amount of 20 mass% or less based on the total mass of the inorganic filler.

[ silane coupling agent ]

Further, from the viewpoint of improving the adhesion to an adherend, a silane coupling agent may be added to the thermosetting resin composition as needed. As the silane coupling agent, the same materials as exemplified as the silane coupling agent for the adhesive composition for a general-purpose die-bonding film can be used in the same manner. The amount of the silane coupling agent to be added is preferably in the range of 0.5 parts by mass to 2.0 parts by mass from the standpoint of suppressing occurrence of voids in the adhesive surface, relative to 100 parts by mass of the total of the epoxy resin and the phenolic resin.

[ others ]

Further, a flame retardant, an ion scavenger, or the like may be added to the thermosetting resin composition within a range that does not impair the function as the die-bonding film 3. As these flame retardants and ion scavengers, the same materials exemplified as the flame retardants and ion scavengers for the adhesive composition for a general-purpose die-bonding film can be used in the same manner.

< thickness of die bonding film >

The thickness of the die bonding film (adhesive layer) 3 is not particularly limited, and is preferably in the range of 5 μm to 200 μm in order to secure the adhesive strength, to appropriately embed the leads for connecting the semiconductor chips, or to sufficiently fill the irregularities of the wiring circuit or the like of the substrate. If the thickness of the die bonding film (adhesive layer) 3 is less than 5 μm, the adhesion between the semiconductor chip and the lead frame, wiring board, or the like may become insufficient. On the other hand, if the thickness of the die bonding film (adhesive layer) 3 exceeds 200 μm, it becomes uneconomical and it is easy to become insufficient to cope with downsizing and thinning of the semiconductor device. In view of high adhesion and the ability to thin a semiconductor device, the film thickness of the film-like adhesive is more preferably in the range of 10 μm to 100 μm, and particularly preferably in the range of 20 μm to 75 μm.

More specifically, the thickness of the die bonding film (adhesive layer) used for general purpose is preferably in the range of 5 μm or more and less than 30 μm, particularly 10 μm or more and 25 μm or less, and the thickness of the die bonding film (adhesive layer) used for lead embedding is preferably in the range of 30 μm or more and 100 μm or less, particularly 40 μm or more and 80 μm or less.

(method for producing die-bonding film)

The die bonding film (adhesive layer) 3 is manufactured by, for example, the following operations. First, a release liner is prepared. As the release liner, the same one disposed on the adhesive layer 2 of the adhesive tape (dicing tape) 10 for wafer processing can be used. Next, a coating solution for the die bonding film (adhesive layer) 3, which is a material for forming the die bonding film (adhesive layer) 3, was prepared. The coating solution can be prepared by, for example, uniformly mixing and dispersing the thermosetting resin composition containing the glycidyl group-containing (meth) acrylate copolymer, the epoxy resin, the curing agent for the epoxy resin, the inorganic filler, the curing accelerator, the silane coupling agent, and the like, which are the constituent components of the die bonding film (adhesive layer) 3, and the diluting solvent. As the solvent, for example, a general-purpose organic solvent such as methyl ethyl ketone or cyclohexanone can be used.

Next, the coating solution for the die-bonding film (adhesive layer) 3 is applied to the release treated surface of the release liner as a temporary support and dried to form the die-bonding film (adhesive layer) 3 having a predetermined thickness. Then, the release treated surface of the other release liner is bonded to the die bonding film (adhesive layer) 3. The coating method is not particularly limited, and for example, a die coater, a half-wheel coater (registered trademark), a gravure coater, a roll coater, a reverse coater, or the like may be used for coating. The drying conditions are preferably, for example, those in which the drying temperature is 60 to 200 ℃ and the drying time is 1 to 90 minutes. In the present invention, a laminate having a release liner on both sides or one side of the die bonding film (adhesive layer) 3 may be referred to as a die bonding film (adhesive layer) 3.

(method for manufacturing dicing die bonding film)

The method for producing the dicing die-bonding film 20 is not particularly limited, and it can be produced by a conventionally known method. For example, the dicing die-bonding film 20 described above can be manufactured as follows: first, the adhesive tape (dicing tape) 10 for wafer processing and the die bonding film 20 are prepared, respectively, and then the release liners of the adhesive layer 2 and the die bonding film (adhesive layer) 3 of the adhesive tape (dicing tape) 10 for wafer processing are peeled off, respectively, and the adhesive layer 2 and the die bonding film (adhesive layer) 3 of the adhesive tape (dicing tape) 10 for wafer processing are bonded by pressure bonding with a pressure bonding roller such as a hot rolling laminator.

The bonding temperature is not particularly limited, and is preferably in the range of 10℃to 100℃and the bonding pressure (line pressure) is preferably in the range of 0.1kgf/cm to 100 kgf/cm. In the present invention, the dicing die bonding film 20 may be referred to as a laminate having a release liner on the adhesive layer 2 and the die bonding film (adhesive layer) 3. In the dicing die bonding film 20, the release liners provided on the adhesive layer 2 and the die bonding film (adhesive layer) 3 may be peeled off when the dicing die bonding film 20 is supplied to the work.

The dicing die bonding film 20 may be formed by laminating sheets having a wide width and being wound in a roll shape. The wafer processing adhesive tape 10 and the die bonding film 3 may be laminated in a sheet or tape shape, which is formed by cutting the wafer processing adhesive tape 10 and the die bonding film 3 to predetermined sizes.

For example, as disclosed in japanese patent application laid-open publication No. 2011-159929, the following modes may be produced: the adhesive layer (die bonding film 3) and the adhesive film (dicing tape 10) which are precut into wafer shapes constituting the semiconductor element are formed in the form of island-shaped film rolls on the release base material (release liner). In this case, dicing tape 10 is formed in a circular shape having a larger diameter than die bonding film (adhesive layer) 3, and die bonding film (adhesive layer) 3 is formed in a circular shape having a larger diameter than semiconductor wafer 30. When the precut is performed in the form of such a film roll, the excess dicing tape 10 is peeled off and removed.

(method for manufacturing semiconductor chip)

Fig. 7 is a flowchart illustrating a method for manufacturing a semiconductor chip using dicing die bonding film 20 in which die bonding film (adhesive layer) 3 is laminated on adhesive layer 2 of adhesive tape (dicing tape) 10 for wafer processing according to the present embodiment. Fig. 8 is a schematic view showing a state in which a ring-shaped frame (wafer ring) 40 is attached to the outer edge portion (exposed portion of the adhesive layer 2) of the wafer processing adhesive tape (dicing tape) 10 for dicing the die bonding film 20, and a semiconductor wafer that can be singulated is attached to the die bonding film (adhesive layer) 3 in the center portion. Further, fig. 9 (a) to (f) are cross-sectional views showing an example of a grinding process of a semiconductor wafer in which a plurality of modified regions are formed by irradiation with laser light and a bonding process of the semiconductor wafer to a dicing die bonding film. Fig. 10 (a) to (f) are cross-sectional views showing examples of manufacturing a semiconductor chip using a thin film semiconductor wafer having a plurality of modified regions to which a dicing die bonding film is bonded.

(method for manufacturing semiconductor chip Using dicing die bonding film 20)

The method for manufacturing the semiconductor chip using the dicing die bonding film 20 is not particularly limited, and any of the above methods may be used, and a method for manufacturing the semiconductor chip using SDBG (stealth dicing before polishing, stealth Dicing Before Griding) is exemplified.

First, as shown in fig. 9 a, a semiconductor wafer W having a plurality of integrated circuits (not shown) mounted on a 1 st surface Wa of a semiconductor wafer W mainly composed of silicon is prepared (step S201 in fig. 7: a preparation step). Then, the back surface polishing tape T having the adhesive surface Ta is attached to the 1 st surface Wa side of the semiconductor wafer W.

Next, as shown in fig. 9 (b), the semiconductor wafer W is irradiated with the laser light focused on the inside of the wafer from the side opposite to the back grinding tape T, that is, from the side of the 2 nd surface Wb of the semiconductor wafer W, along the dividing line X in the lattice shape thereof, and the modified region 30b is formed in the semiconductor wafer W due to ablation by multiphoton absorption (step S202 in fig. 7: modified region forming step). The modified region 30b is a weakened region for dividing and separating the semiconductor wafer W into semiconductor chip units by the cold expansion process. As a method of forming the modified regions 30b along the planned dividing line by irradiating the semiconductor wafer W with laser light, for example, refer to a method disclosed in japanese patent publication No. 3408805, japanese patent application laid-open No. 2002-192370, japanese patent application laid-open No. 2003-338567, and the like.

Next, as shown in fig. 9 (c), the semiconductor wafer W is thinned to a predetermined thickness by grinding from the 2 nd surface Wb in a state where the semiconductor wafer W is held by the back grinding tape T. Here, the thickness of the semiconductor wafer 30 is preferably adjusted to 100 μm or less, more preferably to 10 μm or more and 50 μm or less, from the viewpoint of thinning the semiconductor device. Thus, by the cold expansion in the subsequent step, the semiconductor wafer 30 having the thin film in which the modified regions 30b for dividing the semiconductor chips 30a into a plurality of semiconductor chips are more easily formed can be obtained (step S203 in FIG. 7: grinding and thinning step). In the grinding and thinning process, depending on differences in the final thickness of the semiconductor wafer 30 after grinding, the number of times of laser irradiation (input power), the physical properties of the back grinding tape T, and the like, when a grinding load of the grinding wheel is applied, the semiconductor wafer 30 may grow cracks in the vertical direction starting from the modified region 30b, and the semiconductor wafer may be cut into individual semiconductor chips 30a at this step, or the cracks may not grow and may not be cut.

Next, as shown in fig. 9 (d) and (e), the semiconductor wafer 30 (when the semiconductor wafer 30 has been diced into semiconductor chips 30a, the plurality of semiconductor chips 30 a) having the thin film having the plurality of modified regions 30b inside, which is held by the back grinding tape T, is bonded to the die bonding film 3 of the dicing die bonding film 20 prepared separately (step S204 in fig. 7: bonding step). In this step, after the release liner is peeled from the adhesive layer 2 and the die bonding film (adhesive layer) 3 of the dicing tape 20 cut into a circular shape, as shown in fig. 8, a ring-shaped frame (wafer ring) 40 is attached to the outer edge portion (exposed portion of the adhesive layer 2) of the dicing tape 10 of the dicing tape 20, and a plurality of semiconductor chips 30a are attached to the die bonding film (adhesive layer) 3 laminated on the upper center portion of the adhesive layer 2 of the dicing tape 10, so that the semiconductor wafer 30 of the film which can be processed individually (when the semiconductor wafer 30 has been diced into semiconductor chips 30 a) is attached.

Thereafter, as shown in fig. 9 (f), the back grinding tape T is peeled from the thin semiconductor wafer 30 (when the semiconductor wafer 30 has been diced into semiconductor chips 30a, the plurality of semiconductor chips 30 a). The bonding is performed by pressing with a pressing device such as a pressure roller. The bonding temperature is not particularly limited, and is preferably in the range of 20 ℃ to 130 ℃, more preferably in the range of 40 ℃ to 100 ℃ from the viewpoint of reducing warpage of the semiconductor wafer 30. The bonding pressure is not particularly limited, but is preferably in the range of 0.1MPa to 10.0 MPa. The adhesive tape (dicing tape) 10 for wafer processing of the present invention has a certain heat resistance, and therefore, even if the bonding temperature is high, it is not particularly problematic in terms of handling.

Next, after the annular frame 40 is attached to the adhesive layer 2 of the wafer processing adhesive tape (dicing tape) 10 in the dicing die bonding film 20, as shown in fig. 10 a, the dicing die bonding film 20, which accompanies the semiconductor wafer 30 (in the case where the semiconductor wafer 30 has been diced into semiconductor chips 30a, is a plurality of semiconductor chips 30 a) of the thin film that can be singulated, is fixed to the holder 41 of the expansion device. As shown in fig. 10 (b), the thin film semiconductor wafer 30 has a plurality of modified regions 30b formed therein along the lines X to be cut so that the thin film semiconductor wafer can be singulated into a plurality of semiconductor chips 30 a.

Next, a first expansion step, i.e., a cold expansion step, under relatively low temperature (e.g., 30 ℃ to 0 ℃) is performed as shown in fig. 10 (c), the semiconductor wafer 30 is singulated into a plurality of semiconductor chips 30a, and the die bonding film (adhesive layer) 3 of the dicing die bonding film 20 is diced into small pieces (adhesive layer) 3a corresponding to the size of the semiconductor chips 30a, thereby obtaining semiconductor chips 30a with the die bonding film 3a (step S205 in fig. 7: cold expansion step). In this step, a hollow cylindrical pushing member (not shown) provided in the expansion device is raised by abutting the dicing die-bonding film 20 on the lower side thereof against the dicing die-bonding film 20, and the dicing die-bonding film 20 on which the singulated semiconductor wafers 30 are bonded is expanded so that the dicing die-bonding film 10 is stretched in two dimensions including the radial direction and the circumferential direction of the semiconductor wafers 30.

The wafer processing adhesive tape (dicing tape) 10 expands in all directions by cold expansion to generate internal stress, and the internal stress is transmitted as external stress to the semiconductor wafer 30 that can be processed monolithically and the die bonding film 3 attached to the semiconductor wafer 30. By this external stress, the semiconductor wafer 30 is broken into individual semiconductor chips 30a by growing cracks in the vertical direction starting from the lattice-shaped modified regions 30b formed therein, and the chip bonding film 3 which has been brittle at low temperature is also broken into small pieces of the same size as the semiconductor chips 30a. When the semiconductor wafer 30 has been diced into individual semiconductor chips 30a in the grinding and thinning process, only the die bonding film 3 that has been brittle at low temperature, which is in close contact with the semiconductor chips 30a, is diced into small pieces of the die bonding film 3a corresponding to the size of the semiconductor chips 30a by cold expansion, and the semiconductor chips 30a with the die bonding film 3a are obtained.

The temperature conditions in the cold expansion step are, for example, from-30℃to 0℃and preferably from-20℃to-5℃and more preferably from-15℃to-5℃and particularly preferably from-15 ℃. The expansion speed (the speed at which the hollow cylindrical push-up member is raised) in the cold expansion step is preferably in the range of 0.1 mm/sec to 1000 mm/sec, more preferably in the range of 10 mm/sec to 300 mm/sec. The expansion amount (push-up height of the hollow cylindrical push-up member) in the cold expansion step is preferably 3mm to 16 mm.

In the adhesive tape (dicing tape) 10 for wafer processing of the present invention, the base film 1 is formed by laminating the resin layer containing the ionomer resin in which the ethylene-unsaturated carboxylic acid copolymer containing the constituent units derived from the unsaturated carboxylic acid is crosslinked with the zinc ions at the specific concentration in the specific ratio as described above, and therefore, the development of the ionic aggregates (clusters) in the continuous layer of the ethylene-unsaturated carboxylic acid copolymer becomes sufficient and appropriate, and therefore, even if the base film 1 is expanded, the ionic aggregates (clusters) are not easily broken, and the number of molecular chains between the ionic aggregates increases due to the crosslinking effect. As a result, the internal stress generated by the dicing tape 10 being stretched in all directions by cold expansion is efficiently transmitted to the die bonding film 3 attached to the semiconductor wafer 30, for example, as an external stress, and as a result, the die bonding film 3 is cut into small pieces of the size corresponding to the semiconductor chips 30a with good yield, and the semiconductor chips 30a with the die bonding film 3a are obtained with good yield. Even when a wire-embedded die bonding film having a large thickness and high fluidity (low melt viscosity at high temperature) is used as the die bonding film 3, the die bonding film can be cut off with good yield.

After the cold expansion step, the hollow cylindrical push-up member of the expansion device is lowered to release the expanded state of the wafer processing adhesive tape (dicing tape) 10.

Next, as shown in fig. 10 d, the normal temperature expansion step, which is the second expansion step under relatively high temperature (for example, 10 ℃ to 30 ℃) conditions, is performed, and the distance (kerf width) between the semiconductor chips 30a with the die bonding film (adhesive layer) 3a is enlarged. In this step, a cylindrical pedestal (not shown) provided in the expansion device is raised by abutting the lower side of the dicing die-bonding film 20 against the wafer-processing adhesive tape (dicing tape) 10, and the wafer-processing adhesive tape (dicing tape) 10 for dicing the die-bonding film 20 is expanded (step S206 in fig. 7: normal temperature expansion step). The room temperature expansion process sufficiently ensures the distance (slit width) between the semiconductor chips 30a with the die bonding film (adhesive layer) 3a, thereby improving the recognition of the semiconductor chips 30a by a CCD camera or the like, and preventing the re-adhesion of the semiconductor chips 30a with the die bonding film (adhesive layer) 3a due to the contact between the adjacent semiconductor chips 30a at the time of pickup. As a result, in the pickup step described later, the pickup performance of the semiconductor chip 30a with the die bonding film (adhesive layer) 3a is improved.

The temperature conditions in the normal temperature expansion step are, for example, 10℃to 30℃and preferably 15℃to 30 ℃. The expansion rate (the rate at which the columnar pedestal is raised) in the normal temperature expansion step is, for example, in the range of 0.1 mm/sec to 50 mm/sec, preferably in the range of 0.3 mm/sec to 30 mm/sec. The expansion amount in the normal temperature expansion step is, for example, in the range of 3mm to 20 mm.

After the wafer processing adhesive tape (dicing tape) 10 is inflated at normal temperature by the raising of the pedestal, the pedestal vacuum-sucks the wafer processing adhesive tape (dicing tape) 10. Then, while maintaining the suction by the pedestal, the pedestal is lowered together with the workpiece, and the state of expansion of the wafer processing adhesive tape (dicing tape) 10 is released. In order to suppress the width of the notch of the semiconductor chip 30a with the die bonding film (adhesive layer) 3a on the dicing tape (dicing tape) 10 from becoming narrower after the expansion state is released, it is preferable to keep the wafer processing adhesive tape (dicing tape) 10 in a strained state by blowing hot air while the wafer processing adhesive tape (dicing tape) 10 is vacuum-sucked by the pedestal and heat-shrinking (heat-shrinking) the peripheral portion of the wafer processing adhesive tape (dicing tape) 10 outside the holding area of the semiconductor chip 30a, thereby eliminating the looseness of the wafer processing adhesive tape (dicing tape) 10 due to the expansion. After the heat shrinkage, the vacuum suction state by the pedestal is released.

The temperature of the hot air may be adjusted according to the physical properties of the base film 1, the distance between the hot air outlet and the dicing tape, the air volume, and the like, and is preferably in the range of 200 ℃ to 250 ℃. The distance between the hot air outlet and the wafer processing adhesive tape (dicing tape) 10 is preferably, for example, 15mm to 25 mm. The air volume is preferably in the range of 35L/min to 45L/min, for example. In the heat shrinkage step, for example, the pedestal of the expansion device is rotated at a rotational speed in the range of 3 °/sec to 10 °/sec, and the heat air is blown along the circumferential portion of the wafer processing adhesive tape (dicing tape) 10 outside the holding area of the semiconductor chip 30 a. By such blowing of the heat, the surface temperature of the adhesive tape (dicing tape) 10 for wafer processing is adjusted to, for example, about 80 ℃.

In the adhesive tape (dicing tape) 10 for wafer processing of the present invention, as the base film 1 thereof, a laminated resin layer is used which contains an ionomer resin in which an ethylene-unsaturated carboxylic acid copolymer containing constituent units derived from unsaturated carboxylic acids in a specific ratio is crosslinked with zinc ions at a specific concentration and which has an appropriate vicat softening temperature, so that in a continuous layer of the ethylene-unsaturated carboxylic acid copolymer, the development of ion aggregates (clusters) formed by the bonding of carboxylate ions derived from the acid groups of unsaturated carboxylic acids with ions of zinc ions becomes sufficient and appropriate, and therefore, by the crosslinking effect thereof, the ion aggregates (clusters) are moderately maintained without being completely destroyed even if the base film 1 is heated, and therefore, in the heat shrinkage step after expansion, entropy elasticity strongly acts, and the stretched molecules are easily restored to the original state. That is, the recovery force at the time of heating against the deformation after the stretching of the base film 1 becomes sufficient, and in the heat shrinkage step of the adhesive tape 10 for wafer processing, thermal wrinkles and the like do not occur, and the circumferential portion of the dicing tape 10 is heat shrunk without problems, so that the slack can be eliminated. As a result, a sufficient kerf width between individual semiconductor chips can be ensured, and good pick-up performance can be obtained in a pick-up process described later.

Next, the wafer processing adhesive tape (dicing tape) 10 is irradiated with active energy rays from the substrate film 1 side, whereby the adhesive layer 2 is cured and shrunk, and the adhesion of the adhesive layer 2 to the die bonding film 3a is reduced (step S207 in fig. 7: active energy ray irradiation step). The active energy rays used for the post-irradiation include ultraviolet rays, visible rays, infrared rays, electron rays, β rays, and γ rays. Among these active energy rays, ultraviolet (UV) and Electron Beam (EB) are preferably used, and Ultraviolet (UV) is particularly preferably used. The light source for irradiating the Ultraviolet (UV) rays is not particularly limited, and for example, a black light lamp, an ultraviolet fluorescent lamp, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halogen lamp, a xenon lamp, or the like may be used. In addition, for example, arF excimer laser, krF excimer laser, excimer lamp, synchrotron radiation light, or the like can also be used. The amount of the Ultraviolet (UV) irradiation is not particularly limited, but is preferably 100mJ/cm ² Above 2,000mJ/cm ² The following range is more preferably 300mJ/cm ² Above 1,000mJ/cm ² The following ranges.

Here, in the adhesive tape (dicing tape) 10 for wafer processing of the present invention, in the active energy ray-curable adhesive composition constituting the adhesive layer 2, since the active energy ray-reactive carbon-carbon double bond concentration is controlled to be in the range of, for example, 0.85mmol or more and 1.60mmol or less per 1g of the active energy ray-curable adhesive composition, the adhesive layer 2 after Ultraviolet (UV) irradiation becomes high in crosslinking density by the three-dimensional crosslinking reaction of carbon-carbon double bonds, that is, since the storage elastic modulus is greatly increased and the glass transition temperature is also increased, and the volume shrinkage is also increased, the adhesive force to the die bonding film 3a can be sufficiently reduced. As a result, in the pickup step described later, the pickup of the semiconductor chip 30a with the die bonding film (adhesive layer) 3a becomes good.

Next, the semiconductor chips 30a each having the die bonding film (adhesive layer) 3a cut and singulated by the expansion step are peeled from the Ultraviolet (UV) irradiated adhesive layer 2 of the wafer processing adhesive tape (dicing tape) 10 (step S208 in fig. 7: peeling (picking up) step).

As the method of picking up, for example, as shown in fig. 10 (e), there is a method in which the 2 nd surface of the base film 1 of the adhesive tape (dicing tape) 10 for wafer processing is pushed up by the push-up pin (needle) 60 with respect to the semiconductor chip 30a with the die bonding film (adhesive layer) 3a, and as shown in fig. 10 (f), the semiconductor chip 30a with the die bonding film (adhesive layer) 3a pushed up is sucked by the suction jacket 50 of the pick-up device (not shown) and peeled from the adhesive layer 2 of the adhesive tape (dicing tape) 10 for wafer processing. Thereby, the semiconductor chip 30a with the die bonding film (adhesive layer) 3a is obtained.

The pickup condition is not particularly limited as long as it is practically allowable, and the push-up speed of the push-up pins (pins) 60 is usually set in the range of 1 mm/sec to 100 mm/sec, but in the case where the thickness of the semiconductor chip 30a (the thickness of the semiconductor wafer) is as thin as 100 μm or less, it is preferably set in the range of 1 mm/sec to 20 mm/sec from the viewpoint of suppressing damage of the semiconductor chip 30a of the thin film. From the viewpoint of the incidental productivity, it is more preferable that the ratio is set in the range of 5 mm/sec to 20 mm/sec.

In addition, the push-up height of the push-up pins that can pick up the semiconductor chip 30a without damaging the semiconductor chip is preferably set in a range of 100 μm to 600 μm from the same point of view as described above, and more preferably in a range of 100 μm to 450 μm from the point of view of reducing stress on the semiconductor thin film chip. From the viewpoint of the incidental productivity, it is particularly preferable that the particle diameter be set in the range of 100 μm to 350 μm. The wafer processing adhesive tape (dicing tape) capable of reducing the push-up height is said to be excellent in pick-up property.

As described above, the adhesive tape (dicing tape) 10 for wafer processing of the present invention is composed of the base film 1 and the adhesive layer 2, and when the base film 1 is composed of the laminated resin layer containing the ionomer resin having a proper vicat softening temperature and containing the ethylene-unsaturated carboxylic acid copolymer having the constituent units of the unsaturated carboxylic acid crosslinked with the zinc ions at the specific concentration, for example, even in the case where the die bonding film 20 having a high fluidity and a thick thickness is applied by bonding the lead-in die bonding film, the semiconductor wafer 30 with the die bonding film 3 can be satisfactorily cut by cold expansion, and the adhesive tape (dicing tape) 10 for wafer processing of the present invention can be satisfactorily cut from the adhesive tape (dicing tape) 2 for wafer processing by thermally sealing and dicing the dicing tape) 10 in a state where the dicing film 20 with the die bonding film (adhesive layer) 3 is laminated on the adhesive layer 2 for wafer processing in the semiconductor manufacturing process, for example, the semiconductor wafer 30 with the die bonding film 3 can be satisfactorily cut by thermally expanding and thermally dicing the adhesive tape (dicing tape) 3a can be satisfactorily cut and dicing the die bonding film (dicing tape a) can be satisfactorily processed by dicing tape (dicing tape a) after dicing the dicing tape (dicing tape) from the wafer (dicing tape) 2).

The manufacturing methods described in (a) to (f) of fig. 10 are examples (SDBG) of a manufacturing method of the semiconductor chip 30a using the dicing die bonding film 20, and the method of using the wafer processing adhesive tape (dicing tape) 10 as the form of dicing the die bonding film 20 is not limited to the above method. For example, in the semiconductor wafer W described in fig. 9 (b), instead of the method of forming the modified region 30b along the planned dividing line by irradiating the laser beam, a method of forming a planned-depth dividing groove on the 1 st surface Wa side of the semiconductor wafer W by a rotary knife may be used. In this case, although not shown, the back grinding tape T2 having the adhesive surface T2a is bonded to the 2 nd surface Wb side of the semiconductor wafer W, and then a dicing groove of a predetermined depth is formed on the 1 st surface Wa side of the semiconductor wafer W using a rotary blade such as a dicing device in a state where the back grinding tape T2 holds the semiconductor wafer W. Next, the back surface grinding tape T having the adhesion surface Ta is bonded to the 1 st surface Wa side of the semiconductor wafer W and the back surface grinding tape T2 is peeled from the semiconductor wafer W, so that the state of fig. 9 (b) is obtained. In the grinding and thinning step shown in fig. 9 (c), the semiconductor wafer W may be ground until the dividing groove itself is exposed on the 2 nd surface Wb side, or the semiconductor wafer W may be ground from the 2 nd surface Wb side until the dividing groove is reached, and then a crack may be generated between the dividing groove and the 2 nd surface by the action of the grinding load pressure from the grinding wheel to the semiconductor wafer W, thereby forming a divided body (a plurality of semiconductor chips 30 a) of the semiconductor wafer W. The depth of the formed dividing groove from the 1 st surface Wa is appropriately determined according to the method employed.

As described above, the dicing die bonding film 20 of the present embodiment can be used without being limited to the above method as long as it is attached to the semiconductor wafer 30 at the time of dicing.

Among them, the adhesive tape (dicing tape) 10 for wafer processing of the present invention is suitable for use in a manufacturing method for obtaining a thin film semiconductor chip such as DBG, dicing stealth, SDBG, and the like, particularly as a dicing tape for use as a dicing die bonding film for integration with a wire-embedding die bonding film. Of course, the film can be used integrally with a general-purpose die bonding film.

(method for manufacturing semiconductor device)

Hereinafter, a semiconductor device mounted with a semiconductor chip manufactured using dicing die bonding film 20 obtained by integrating dicing die bonding film 3 with wafer processing adhesive tape (dicing tape) 10 to which the present embodiment is applied will be described in detail.

The semiconductor device (semiconductor package) can be obtained, for example, as follows: the semiconductor chip 30a with the die bonding film (adhesive layer) 3a is bonded by heat press bonding to a semiconductor chip mounting support member or a semiconductor chip, and then subjected to a wire bonding step, a sealing step using a sealing material, and the like.

Fig. 11 is a schematic cross-sectional view of one embodiment of a semiconductor device having a stacked structure in which semiconductor chips are mounted, the semiconductor chips being manufactured using dicing die bonding film 20 obtained by integrating dicing adhesive tape (dicing tape) 10 for wafer processing and wire-embedded die bonding film 3 to which the present embodiment is applied. The semiconductor device 70 shown in fig. 11 includes: the semiconductor chip mounting support substrate 4, cured chip bonding films (adhesive layers) 3a1, 3a2, the first stage semiconductor chip 30a1, the second stage semiconductor chip 30a2, and the sealing material 8. The semiconductor chip mounting support substrate 4, the cured die bonding film 3a1, and the semiconductor chip 30a1 constitute a support member 9 of the semiconductor chip 30a 2.

A plurality of external connection terminals 5 are arranged on one surface of the semiconductor chip mounting support substrate 4, and a plurality of terminals 6 are arranged on the other surface of the semiconductor chip mounting support substrate 4. The semiconductor chip mounting support substrate 4 has leads 7 for electrically connecting the connection terminals (not shown) of the semiconductor chip 30a1 and the semiconductor chip 30a2 to the external connection terminals 5. The semiconductor chip 30a1 is bonded to the semiconductor chip mounting support substrate 4 through the cured die bonding film 3a1 so as to embed the irregularities from the external connection terminals 5. The semiconductor chip 30a2 is adhered to the semiconductor chip 30a1 through the cured die bonding film 3a 2. The semiconductor chip 30a1, the semiconductor chip 30a2, and the leads 7 are sealed with the sealing material 8. In this way, the wire-embedded die bonding film 3a can be suitably used for a semiconductor device having a laminated structure in which a plurality of semiconductor chips 30a are stacked.

Fig. 12 is a schematic cross-sectional view of one embodiment of another semiconductor device on which a semiconductor chip manufactured using dicing die bonding film 20 obtained by integrating dicing tape (dicing tape) 10 for wafer processing to which the present embodiment is applied and general-purpose die bonding film 3 is mounted. The semiconductor device 80 shown in fig. 12 includes: the semiconductor chip mounting support substrate 4, the cured die bonding film 3a, the semiconductor chip 30a, and the sealing material 8. The semiconductor chip mounting support substrate 4 is a support member for the semiconductor chip 30a, and includes leads 7 for electrically connecting connection terminals (not shown) of the semiconductor chip 30a and external connection terminals (not shown) disposed on a main surface of the semiconductor chip mounting support substrate 4. The semiconductor chip 30a is bonded to the semiconductor chip mounting support substrate 4 through the cured die bonding film 3 a. The semiconductor chip 30a and the leads 7 are sealed with the sealing material 8.

Examples

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

1. Production of base film 1

The following resins were prepared as materials for producing the base films 1 (a) to (z), respectively. As a zinc (zn2+) ion supply source for the ionomer resin, a mixture of zinc oxide/zinc stearate=99/1 by mass ratio was used.

(resin formed from an ionomer of an ethylene-unsaturated carboxylic acid copolymer)

(1) Resin (IO-1)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.38mmol, vicat softening temperature: 56 DEG C

(2) Resin (IO-2)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.41mmol, vicat softening temperature: 57 DEG C

(3) Resin (IO-3)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.46mmol, vicat softening temperature: 57 DEG C

(4) Resin (IO-4)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.52mmol, vicat softening temperature: 57 DEG C

(5) Resin (IO-5)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.55mmol, vicat softening temperature: 57 DEG C

(6) Resin (IO-6)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/8/12 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.41mmol, vicat softening temperature: 55 DEG C

(7) Resin (IO-7)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/12/8 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.41mmol, vicat softening temperature: 58 DEG C

(8) Resin (IO-8)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/15/5 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.41mmol, vicat softening temperature: 56 DEG C

(9) Resin (IO-9)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=91.6/6.9/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.38mmol, vicat softening temperature: 64 DEG C

(10) Resin (IO-10)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=77.1/6.9/16 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.38mmol, vicat softening temperature: 50 DEG C

(11) Resin (IO-12)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=88.1/6.9/5 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.38mmol, vicat softening temperature: 74 DEG C

(12) Resin (IO-13)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80.5/18/1.5 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.41mmol, vicat softening temperature: 51 DEG C

(13) Resin (IO-14)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80.5/18/1.5 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.60mmol, vicat softening temperature: 51 DEG C

(14) Resin (IO-15)

Zinc ionomer resin of a binary copolymer formed from ethylene/methacrylic acid=82/18 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.38mmol, vicat softening temperature: 54 DEG C

(15) Resin (IO-16)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=80/10/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.35mmol, vicat softening temperature: 56 DEG C

(16) Resin (IO-17)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=85/5/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.29mmol, vicat softening temperature: 70 DEG C

(17) Resin (IO-18)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=78/19/3 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.35mmol, vicat softening temperature: 44 DEG C

(18) Resin (IO-19)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=93/4/3 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.22mmol, vicat softening temperature: 87 DEG C

(19) Resin (IO-20)

Zinc ionomer resin of terpolymer formed from ethylene/methacrylic acid/isobutyl acrylate=75/15/10 mass ratio, zinc (zn2+) ion concentration per 1g copolymer: 0.83mmol, vicat softening temperature: 57 DEG C

(resin mixture of resin formed from ionomer of ethylene-unsaturated carboxylic acid copolymer and other resin)

(20) Mixed resin (IO-2/PA)

A mixed resin obtained by dry-mixing a zinc ionomer resin (IO-2) of a terpolymer formed of ethylene/methacrylic acid/isobutyl acrylate=80/10/10 in a mass ratio of 90:10 with a polyamide resin "Amilan (registered trademark) CM1017" (PA) manufactured by ori corporation, and a vicat softening temperature of the mixed resin obtained by melt-kneading at a single screw extruder die temperature of 230 ℃:61 DEG C

(21) Mixed resin (IO-2/TPO-1)

A blended resin obtained by dry-blending a zinc ionomer resin (IO-2) of a terpolymer formed of ethylene/methacrylic acid/isobutyl acrylate=80/10/10 in a mass ratio of 80:20 with a polypropylene elastomer "Zelas (registered trademark) 5053" (TPO-1) manufactured by mitsubishi chemical corporation, and melt-kneading the blend resin at a single screw extruder die temperature of 230 ℃ to obtain a vicat softening temperature: 55 DEG C

(ethylene-unsaturated carboxylic acid-based copolymer resin)

(22) Resin (EMAA)

Bipolymer formed by ethylene/methacrylic acid=96/4 mass ratio, vicat softening temperature: 92 DEG C

(olefin thermoplastic elastomer)

(23) Resin (TPO-1)

Polypropylene elastomer "Zelas (registered trademark) 5053" manufactured by mitsubishi chemical corporation, propylene/ethylene=79/21 mass ratio, vicat softening temperature: 50 DEG C

(24) Resin (TPO-2)

Multistage polymerized propylene/ethylene copolymer [ Reactor-TPO ] "Cataloy (registered trademark)", manufactured by Liandbarsel company, vicat softening temperature: 59 DEG C

Substrate film 1 (a) >

Ionomer resin (IO-1) was fed into each extruder of 1 (same resin) 3-layer T-die film forming machine, and formed at 240℃to prepare a base film 1 (a) having a thickness of 90 μm and having a 3-layer structure of the same resin. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with the adhesive layer 2)/second resin layer/third resin layer=30 μm/30 μm. The content ratio of the specific ionomer resin in each resin layer was 100 mass%. The total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1 (a).

Substrate films 1 (b) to 1 (j), 1 (l) to 1 (n) >

Base material films 1 (b) to 1 (j) and 1 (l) to 1 (n) were produced in the same manner as base material film 1 (a), except that ionomer resins (IO-1) were changed to ionomer resins (IO-2) to (IO-10) and (IO-12) to (IO-14), respectively. The content ratio of the specific ionomer resin in each of the resin layers of the base films 1 (b) to 1 (j), 1 (l) to 1 (n) was 100 mass%. The total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1.

Substrate film 1 (o) >

An ionomer resin (IO-15) was prepared as a resin composition for the first resin layer and a resin composition for the third resin layer, an ionomer resin (IO-1) was prepared as a resin composition for the second resin layer, and the resin compositions were fed into respective extruders of 2 (resin) 3-layer T-die film forming machines, and were formed at a processing temperature of 240℃to prepare a base film 1 (o) of 2 resins having a 3-layer structure and a thickness of 90. Mu.m. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with adhesive layer 2)/second resin layer/third resin layer=20 μm/50 μm/20 μm. The content ratio of the specific ionomer resin in each resin layer was 100 mass%. The total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1 (o).

Substrate film 1 (p) >

The ionomer resin (IO-2) was prepared as the resin composition for the first resin layer, the ionomer resin (IO-3) was prepared as the resin composition for the second resin layer, the ionomer resin (IO-4) was prepared as the resin composition for the third resin layer, and the resin composition was fed into each extruder of 3 (resin) 3-layer T-die film forming machines, and formed at a processing temperature of 240℃to prepare a base film 1 (p) of 3-layer structure having a thickness of 90. Mu.m of 3 resins. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with the adhesive layer 2)/second resin layer/third resin layer=30 μm/30 μm. The content ratio of the specific ionomer resin in each resin layer was 100 mass%. The total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1 (p).

Substrate film 1 (q) >

An ionomer resin (IO-2) was prepared as a resin composition for the first resin layer and the second resin layer, a resin composition for the third resin layer was prepared as a resin composition of a mixed resin (IO-2/PA) of an ionomer resin and a polyamide resin, and the mixture was fed into respective extruders of 2 (resin) 3-layer T-die film forming machines, and formed at a processing temperature of 240℃to produce a base film 1 (q) of 2 resins having a 3-layer structure and a thickness of 90. Mu.m. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with the adhesive layer 2)/second resin layer/third resin layer=30 μm/30 μm. The content ratio of the specific ionomer resin in the first resin layer and the second resin layer was 100 mass%, and the content ratio of the specific ionomer resin in the third resin layer was 90 mass%. The total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1 (q).

Substrate film 1 (r) >

An ionomer resin (IO-2) was prepared as a resin composition for the first resin layer, a resin composition for the second resin layer was prepared as a resin composition for the mixed resin (IO-2/TPO-1) of the ionomer resin and the olefin thermoplastic elastomer resin, and the mixture was fed into each extruder of a 2-layer (resin) 2-layer T-die film forming machine, and formed at a processing temperature of 240℃to produce a 2-layer structure of 2 resins having a thickness of 70 μm as a base film 1 (r). The second resin layer side (the side opposite to the side in contact with the first resin layer) was subjected to matting processing. The thickness of each resin layer was set to be first resin layer (side in contact with the adhesive layer 2)/second resin layer=50 μm/20 μm. The content ratio of the specific ionomer resin in the first resin layer was 100 mass%, and the content ratio of the specific ionomer resin in the second resin layer was 80 mass%. The total thickness of the resin layers (first resin layer and second resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 100% of the total thickness of the base film 1 (r).

Substrate film 1(s) >

An ionomer resin (IO-2) was prepared as a resin composition for the first resin layer and a resin composition for the third resin layer, an olefin thermoplastic elastomer resin (TPO-1) was prepared as a resin composition for the second resin layer, and the resin compositions were fed into respective extruders of 2 (resin) 3-layer T-die film forming machines, and were formed at a processing temperature of 240℃to prepare a base film 1(s) of 2 resins having a 3-layer structure and a thickness of 90. Mu.m. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with adhesive layer 2)/second resin layer/third resin layer=40 μm/10 μm/40 μm. The content ratio of the specific ionomer resin in the first resin layer and the third resin layer was 100 mass%. The total thickness of the resin layers (first resin layer and third resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 89% of the total thickness of the base film 1(s).

Substrate film 1 (t) >

An ionomer resin (IO-2) was prepared as a resin composition for the first resin layer and the second resin layer, an olefin thermoplastic elastomer resin (TPO-2) was prepared as a resin composition for the third resin layer, and the resin composition was fed into respective extruders of 2 (resin) 3-layer T-die film forming machines, and formed at a processing temperature of 240℃to prepare a base film 1 (T) having a thickness of 120 μm in a 3-layer structure of 2 resins. The matting process was performed on the third resin layer side (the side opposite to the side in contact with the second resin layer). The thickness of each resin layer was set to be first resin layer (side in contact with adhesive layer 2)/second resin layer/third resin layer=40 μm/40 μm. The content ratio of the specific ionomer resin in the first resin layer and the second resin layer was 100 mass%. The total thickness of the resin layers (first resin layer and second resin layer) containing the specific ionomer resin in a content ratio of 80 mass% or more is 67% of the total thickness of the base film 1 (t).

Substrate films 1 (u) to 1 (y) >

Base material films 1 (u) to 1 (y) were produced in the same manner as base material film 1 (a), except that ionomer resins (IO-1) were changed to ionomer resins (IO-16) to (IO-20), respectively. The substrate film 1 (y) using the ionomer resin (IO-20) had a small Melt Flow Rate (MFR) and failed to stabilize the film.

Substrate film 1 (z) >

An ionomer resin (IO-16) was prepared as a resin composition for the first resin layer, an ethylene-unsaturated carboxylic acid copolymer resin (EMAA) was prepared as a resin composition for the second resin layer, and the resin composition was fed into respective extruders of 2 (resin) 2-layer T-die film forming machines, and formed at a processing temperature of 240℃to prepare a 2-layer structure of 2 resins with a thickness of 100. Mu.m, as a base film 1 (z). The thickness of each resin layer was set to be first resin layer (side in contact with the adhesive layer 2)/second resin layer=40 μm/60 μm.

2. Preparation of solution of adhesive composition

As the adhesive composition for the adhesive layer 2 of the dicing tape 10, a solution of the following active energy ray-curable acrylic adhesive composition 2 (a) was prepared.

(solution of active energy ray-curable acrylic pressure-sensitive adhesive composition 2 (a))

As the comonomer components, 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA) and Methyl Methacrylate (MMA) were prepared. These comonomer components were mixed so as to achieve a copolymerization ratio of 2-EHA/2-HEA/mma=78.5 parts by mass/21.0 parts by mass/0.5 parts by mass (= 425.94mmol/180.85mmol/5.81 mmol), and a solution of a base polymer (acrylate copolymer) having a hydroxyl group was synthesized by solution radical polymerization using ethyl acetate as a solvent and Azobisisobutyronitrile (AIBN) as an initiator. The Tg of the matrix polymer obtained, calculated by Fox formula, was-60 ℃.

Next, as an active energy ray-reactive compound produced by Showa electric Co., ltd., 2-isocyanatoethyl methacrylate (trade name: karenzMOI, molecular weight: 155.15, 1/1 molecule of isocyanato group, 1/1 molecule of double bond group) having an isocyanate group and an active energy ray-reactive carbon-carbon double bond was mixed with 100 parts by mass of the solid content of the matrix polymer, and the mixture was reacted with a part of the hydroxyl groups of 2-HEA to synthesize a solution (solid content concentration: 50% by mass, weight average molecular weight Mw:38 ten thousand, solid content hydroxyl value: 21.1mgKOH/g, solid content acid value: 2.7mgKOH/g, carbon-carbon double bond content: 1.12 mmol/g) of an acrylic adhesive polymer (A) having a carbon-carbon double bond in a side chain. In the above reaction, 0.05 parts by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor for maintaining the reactivity of carbon-carbon double bonds.

Next, 200 parts by mass (100 parts by mass in terms of solid content) of the solution of the above-described synthetic acrylic adhesive polymer (a) was blended with 2.0 parts by mass of an α -hydroxyalkylphenone photopolymerization initiator (trade name: omnirad 184) manufactured by IGM Resins b.v. company, 0.4 parts by mass of an acylphosphine oxide photopolymerization initiator (trade name: omnirad 819) manufactured by IGM Resins b.v. company, and 2.56 parts by mass (trade name: coronate L-45E, solid content concentration: 45 mass%) of a TDI-based polyisocyanate crosslinking agent (trade name: coronate L-45E, solid content concentration: 45 mass%) manufactured by eastern co., as a crosslinking agent) (1.15 parts by mass in terms of solid content, 1.75 mmol) in a ratio, and diluted with ethyl acetate and stirred to prepare a solution of the active energy ray-curable acrylic adhesive composition 2 (a) having a solid content of 22 mass%.

3. Preparation of solution of adhesive composition

As the adhesive composition for the die bonding film (adhesive layer) 3 of the dicing die bonding film 20, solutions of the following adhesive compositions 3 (a) to 3 (d) were prepared.

(solution of adhesive composition 3 (a))

As a use of the wire embedding die bonding film, the following adhesive composition solution 3 (a) was prepared and prepared. First, cyclohexanone as a solvent was added to a resin composition containing bisphenol type epoxy resin manufactured by Printec, a product name of thermosetting resin (trade name: R2710, epoxy equivalent: 170, molecular weight: 340, liquid at ordinary temperature), 26 parts by mass of cresol novolak type epoxy resin (trade name: YDCN-700-10, epoxy equivalent 210, softening point 80 ℃ C.) manufactured by Toyo Kagaku K.K., 36 parts by mass of phenolic resin (trade name: milex XLC-LL, hydroxyl equivalent: 175, softening point: 77 ℃, WATER absorption: 1% by mass, heating mass reduction: 4% by mass), 1 part by mass of phenolic resin (trade name: HE200C-10, hydroxyl equivalent: 200, softening point: 71 ℃, WATER absorption: 1% by mass, heating mass reduction: 4% by mass), 25 parts by mass of phenolic resin (trade name: HE-10, hydroxyl equivalent: 101, softening point: 83 ℃, heating mass reduction: 3% by mass 12 parts by mass, silica dispersion (trade name: SC) manufactured by mass of inorganic filler: 80. Mu.H 15, WATER absorption: 25% by mass of WATER dispersion (trade name: hm, 25. 25% by mass of WATER absorption: 80. Mu.H 15, 25% of filler manufactured by Hm of WATER dispersion, 25% by Hm of WATER absorption: 80; average particle diameter of silica dispersion (trade name: 80. WATER absorption: 80; WATER absorption: 60; WATER average particle diameter: 25. Mu.water absorbent: 25. WATER absorbent: hm of WATER absorbent, 25 of Japanese filler, 25,500), average particle diameter: 0.016 μm) 1 part by mass.

Next, a solution of 9 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-30B-CHN, glycidyl (meth) acrylate content: 8 parts by mass, weight average molecular weight Mw:23 ten thousand, tg: -7 ℃) and 37 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-3CSP, glycidyl (meth) acrylate content: 3 parts by mass, weight average molecular weight Mw:80 ten thousand, tg: -7 ℃) manufactured by Dain Kagaku corporation, gamma-ureido propyl triethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba corporation, gamma-ureido propyl triethoxysilane (trade name: NUC A-189) manufactured by GE glossy (trade name: 0.3 parts by mass) manufactured by Dashiba corporation, 1-cyanoethyl-2-phenyl imidazole (trade name: 3% manufactured by Pm Kagaku corporation) as a curing accelerator and 3 parts by mass, and 100% by mass of a solid content (trade name: 3% were mixed and deaerated was stirred and filtered, and the solution was prepared to obtain a solution of 100% by vacuum filtration. The content ratio of each resin component in the total amount of resin components (total mass of thermoplastic resin, thermosetting resin and crosslinking agent) was glycidyl group-containing (meth) acrylate copolymer: epoxy resin: phenolic resin=31.5 mass%: 42.5 mass%: 26.0 mass%. The content of the inorganic filler was 20.5% by mass based on the total amount of the resin components. The die bonding film (adhesive layer) 3 formed from the solution of the adhesive composition 3 (a) had a shear viscosity of 3,800pa·s at 80 ℃.

(solution of adhesive composition 3 (b))

As a use of the wire embedding die bonding film, the following adhesive composition solution 3 (b) was prepared and prepared. First, cyclohexanone as a solvent was added to a resin composition containing bisphenol F type epoxy resin (trade name: YDF-8170C, epoxy equivalent 159, molecular weight 310, liquid at ordinary temperature) 21 parts by mass, cresol novolak type epoxy resin (trade name: YDCN-700-10, epoxy equivalent 210, softening point 80 ℃) 33 parts by mass, phenol resin (trade name: HE200C-10, hydroxyl equivalent 200, softening point: 71 ℃, WATER absorption: 1 mass%, heating mass reduction: 4 mass%) manufactured by AIR WATER Co., ltd., as a crosslinking agent, and silica filler dispersion (trade name: SC1030-HJA, average particle diameter: 0.25 μm) 18 parts by mass manufactured by Admatechs Co., as an inorganic filler.

Next, 16 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-30B-CHN, glycidyl (meth) acrylate content: 8 parts by mass, weight average molecular weight Mw:23 ten thousand, tg: -7 ℃ C.), 16 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-3CSP, glycidyl (meth) acrylate content: 3 parts by mass, weight average molecular weight Mw:80 ten thousand, tg: -7 ℃ C.) 64 parts by mass, gamma-ureido propyl triethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba as a silane coupling agent, 0.6 parts by mass of gamma-ureido propyl triethoxysilane (trade name: NUC A-189) manufactured by GE glossy ganoderma Co., ltd., 1-cyanoethyl-2-phenyl imidazole (trade name: curei 2) manufactured by Pc, 5 parts by Pc, 3 parts by weight, and a solid content of a solid component (trade name: 20% by vacuum filter were added to the resin composition, and a vacuum filter was prepared, and the mixture was deaerated. The content ratio of each resin component in the total amount of resin components (total mass of thermoplastic resin, thermosetting resin and crosslinking agent) was glycidyl group-containing (meth) acrylate copolymer: epoxy resin: phenolic resin=44.4 mass%: 30.0 mass%: 25.6 mass%. The content of the inorganic filler was 10.0 mass% relative to the total amount of the resin components. The die bonding film (adhesive layer) 3 formed from the solution of the adhesive composition 3 (b) had a shear viscosity of 9,700pa·s at 80 ℃.

(solution of adhesive composition 3 (c))

As a use of the wire embedding die bonding film, the following adhesive composition solution 3 (c) was prepared and prepared. First, cyclohexanone as a solvent was added to a resin composition containing 11 parts by mass of a bisphenol type epoxy resin (trade name: R2710, epoxy equivalent: 170, molecular weight: 340, liquid at ordinary temperature) manufactured by Printec, and dicyclopentadiene type epoxy resin (trade name: HP-7200H, epoxy equivalent: 280, softening point) manufactured by DIC, and mixed with stirring, and dispersed for 90 minutes using a bead mill; 83 ℃ C.) 40 parts by mass, bisphenol S-type epoxy resin (trade name: EXA-1514, epoxy equivalent: 300, softening point: 75 ℃ C.) 18 parts by mass, phenol resin (trade name: milex XLC-LL, hydroxyl equivalent: 175, softening point: 77 ℃ C., WATER absorption rate: 1% by mass, heating mass reduction rate: 4% by mass) manufactured by DIC Co., ltd., 1 part by mass, phenol resin (trade name: HE200C-10, hydroxyl equivalent: 200, softening point: 71 ℃ C., WATER absorption rate: 1% by mass, heating mass reduction rate: 4% by mass), phenol resin (trade name: HE910-10, hydroxyl equivalent: 101, softening point: 83 ℃ C., WATER absorption rate: 1% by mass, heating mass reduction rate: 3% by mass) 10 parts by mass, silica filler dispersion (trade name: SC1030-HJ, average particle size: 0.25. Mu.m), silica filler dispersion (trade name: 24.24. Mu.m., manufactured by Nippon silicon dioxide SIL 2) manufactured by AIR WATER Co., ltd., 10 by Mitsche, 3% by Mitso chemical Co., ltd., as a crosslinking agent, and 3% by mass, average particle diameter: 0.016 μm) 0.8 parts by mass.

Next, a solution of 0.57 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-30B-CHN, manufactured by Daiko Kagaku Co., ltd., weight average molecular weight Mw:23 ten thousand, tg: -7 ℃ C.) 30 parts by mass, 3 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-3CSP, manufactured by Daiko Kagaku Co., ltd., weight average molecular weight Mw:80 ten thousand, tg: -7 ℃ C.) 7.5 parts by mass, a gamma-ureido propyl triethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba Co., ltd., gamma-ureido propyl triethoxysilane (trade name: NUC A-189) 0.29 parts by mass, a gamma-ureido propyl triethoxysilane (trade name: NUC A-189) manufactured by GE Toshiba, 1-cyano-2-phenyl imidazole (trade name: 1-3 parts by Daiko Kagaku Co., ltd., 3% by mass, weight average molecular weight Mw:80 ten, 80% Tg: -7 ℃ C.) and 100% by mass of a solid content (Czoto 100% by mass) was prepared by filtration, and a vacuum filtration was stirred, and the solution was prepared. The content of each resin component in the total amount of resin components (total mass of thermoplastic resin, thermosetting resin and crosslinking agent) was glycidyl group-containing (meth) acrylate copolymer: epoxy resin: phenolic resin=27.3 mass%: 50.2 mass%: 22.5 mass%. The content of the inorganic filler was 18.0 mass% relative to the total amount of the resin components. The die bonding film (adhesive layer) 3 formed from the solution of the adhesive composition 3 (c) had a shear viscosity of 3,600pa·s at 80 ℃.

(solution of adhesive composition 3 (d))

As a general purpose die bonding film application, a solution of the following adhesive composition 3 (d) was prepared and prepared. First, cyclohexanone as a solvent was added to a resin composition containing 54 parts by mass of cresol novolak type epoxy resin (trade name: YDCN-700-10, epoxy equivalent: 210, softening point: 80 ℃) manufactured by Toyo Kagaku Co., ltd., 46 parts by mass of phenolic resin (trade name: milex XLC-LL, hydroxyl equivalent: 175, water absorption: 1.8%) manufactured by Mimex chemical Co., ltd., as a crosslinking agent, and 32 parts by mass of silica (trade name: AEROSIL R972, average particle diameter: 0.016 μm) manufactured by Japanese Aerosil Co., ltd., as an inorganic filler, and stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, 274 parts by mass of a glycidyl (meth) acrylate-containing copolymer (trade name: HTR-860P-3CSP, glycidyl (meth) acrylate content: 3% by mass, weight average molecular weight Mw:80 Wan, tg: -7 ℃ C.) manufactured by Daikin chemical Co., ltd., as a thermoplastic resin, 5.0 parts by mass of gamma-ureidopropyltriethoxysilane (trade name: NUC A-1160) manufactured by GE Toshiba Co., ltd., as a silane coupling agent, 1.7 parts by mass of gamma-ureidopropyltriethoxysilane (trade name: NUC A-189) manufactured by GE Toshiba Co., ltd., and 0.1 part by mass of 1-cyanoethyl-2-phenylimidazole (trade name: curezol 2 PZ-CN) manufactured by Sikukuku chemical Co., ltd., as a curing accelerator were added to the above resin composition, and the mixture was stirred and filtered using a 100-mesh filter, followed by vacuum degassing to prepare a solution of the adhesive composition 3 (d) having a solid content of 20% by mass. The content of each resin component in the total amount of resin components (total mass of thermoplastic resin, thermosetting resin and crosslinking agent) was glycidyl group-containing (meth) acrylate copolymer: epoxy resin: phenolic resin=73.3 mass%: 14.4 mass%: 12.3 mass%. The content of the inorganic filler was 8.6 mass% relative to the total amount of the resin components. The die bonding film (adhesive layer) 3 formed from the solution of the adhesive composition 3 (d) had a shear viscosity of 30,300pa·s at 80 ℃.

4. Production of adhesive tape (dicing tape) 10 and dicing die bonding film 20 for wafer processing

Example 1

The solution of the active energy ray-curable acrylic adhesive composition (a) was applied to the release treated surface side of a release liner (thickness: 38 μm, polyethylene terephthalate film) so that the thickness of the dried adhesive layer 2 became 10 μm, and the solvent was dried by heating at 100 ℃ for 3 minutes, and then the surface of the first resin layer side of the base film 1 (a) was bonded to the adhesive layer 2, whereby a raw roll of the dicing tape 10 was produced. Thereafter, the raw roll of the dicing tape 10 was stored at a temperature of 40 ℃ for 48 hours, and the adhesive layer 2 was crosslinked and cured.

Next, a solution of the adhesive composition 3 (a) for forming the die-bonding film (adhesive layer) 3 was prepared, and the solution of the adhesive composition 3 (a) was applied to the release-treated surface side of the release liner (thickness 38 μm, polyethylene terephthalate film) so that the thickness of the dried die-bonding film (adhesive layer) 3 became 30 μm, and heated at a temperature of 90 ℃ for 5 minutes, followed by a 2-stage heating at a temperature of 140 ℃ for 5 minutes, whereby the solvent was dried to prepare the die-bonding film (adhesive layer) 3 having a release liner. If necessary, a protective film (for example, a polyethylene film) may be attached to the dry surface side of the die bonding film (adhesive layer) 3.

Next, the die bonding film (adhesive layer) 3 provided with a release liner thus produced was cut into a circular shape having a diameter of 335mm for each release liner, and the adhesive layer exposed surface (surface without release liner) of the die bonding film (adhesive layer) 3 was bonded to the adhesive layer 2 surface of the dicing tape 10 from which the release liner was peeled. The bonding conditions were set at 23℃and 10 mm/sec, and the line pressure was 30kgf/cm.

Finally, the dicing tape 10 was cut into a circular shape having a diameter of 370mm, and a dicing die bonding film 20 (DDF (a)) was produced in which a circular die bonding film (adhesive layer) 3 having a diameter of 335mm was laminated on the upper center portion of the adhesive layer 2 of the dicing sheet 10 having a circular diameter of 370 mm.

Examples 2 to 19

Dicing die bonding films 20 (DDF (b) to DDF (j), DDF (l) to DDF (t)) were produced in the same manner as in example 1, except that the base film 1 (a) was changed to the base films 1 (b) to 1 (j), 1 (l) to 1 (t) shown in tables 1 to 3, respectively.

Example 20

A dicing die bonding film 20 (DDF (u)) was produced in the same manner as in example 2, except that the solution of the adhesive resin composition 3 (a) was changed to the solution of the adhesive composition 3 (b).

Example 21

A dicing die-bonding film 20 (DDF (v)) was produced in the same manner as in example 2, except that the solution of the adhesive resin composition 3 (a) was changed to the solution of the adhesive composition 3 (c).

Example 22

A dicing die bonding film 20 (DDF (w)) was produced in the same manner as in example 2, except that the solution of the adhesive resin composition 3 (a) was changed to the solution of the adhesive composition 3 (d), and the thickness of the dried die bonding film (adhesive layer) 3 was changed to 20 μm.

Example 23

A dicing die bonding film 20 (DDF (x)) was produced in the same manner as in example 3, except that the thickness of the dried die bonding film (adhesive layer) 3 was changed to 50 μm.

Comparative examples 1 to 6

Dicing die bonding films 20 (DDF (y) to DDF (dd)) were produced in the same manner as in example 1, except that the base film 1 (a) was changed to the base films 1 (u) to 1 (z) shown in table 4, respectively. In comparative example 5, since the base film 1 (y) was not stably produced, the dicing die bonding film (DDF (cc)) was not produced.

5. Evaluation method of dicing die bonding film

The dicing tapes 10 and dicing die-bonding films 20 (DDF (a) to DDF (j), DDF (l) to DDF (dd)) produced in examples 1 to 23 and comparative examples 1 to 6 were measured and evaluated in the following manner.

5.1 measurement of shear viscosity of die bonding film (adhesive layer) 3 at 80 ℃

The shear viscosity at 80℃was measured for each die bonding film (adhesive layer) 3 film formed from the solutions of the adhesive compositions 3 (a) to 3 (d) by the following method. The laminate was produced by bonding a plurality of die bonding films (adhesive layers) 3 each having a release liner removed thereto at 70 c so that the total thickness thereof was 200 to 210 μm. Next, the laminate was die-cut into a size of 10mm×10mm in the thickness direction to obtain a measurement sample. Next, a circular aluminum plate jig having a diameter of 8mm was assembled using a dynamic viscoelasticity device ARES (Rheometric Scientific F.E., manufactured by Corp.) and then the measurement sample was set. The measurement sample was subjected to a deformation of 5% at 35℃and a shear viscosity was measured while heating the measurement sample at a heating rate of 5℃per minute, to obtain a value of the shear viscosity at 80 ℃.

5.2 evaluation of invisible cuttability of dicing die bonding film 20

5.2.1 die bonding film (adhesive layer) 3 cuttability

First, a semiconductor wafer (silicon mirror wafer, thickness 750 μm, outer diameter 12 inches) W was prepared, and a commercially available back grinding tape was stuck on one surface. Next, from the opposite surface of the semiconductor wafer W to the side to which the back surface grinding tape was attached, a modified region 30b was formed at a predetermined depth of the semiconductor wafer W by irradiating laser light along a predetermined dividing line in a lattice shape so that the size of the semiconductor chip 30a after dicing became 4.5mm×7.0mm using a stealth dicing laser saw (device name: DFL 7361) manufactured by DISCO corporation.

Laser irradiation conditions

(1) Laser oscillator model: semiconductor laser excited Q-switched solid laser

(2) Wavelength: 1342nm

(3) Oscillation form: pulse

(4) Frequency: 90kHz

(5) Output power: 1.7W

(6) Movement speed of the stage for the semiconductor wafer: 700 mm/sec

Next, the semiconductor wafer W having a thickness of 750 μm, which was held in the modified region 30b of the back surface polishing tape, was ground and thinned using a back surface polishing apparatus (apparatus name: DGP 8761) manufactured by DISCO corporation, to obtain a semiconductor wafer 30 having a thickness of 30 μm. In the step of the back grinding (grinding) step, the semiconductor wafer 30 is divided into semiconductor chips 30a of a predetermined size by vertically advancing a crack from the modified region 30b formed on the predetermined dividing line on the back grinding tape. Next, the adhesive layer 3, which is one of the index items of the invisible cuttability, was evaluated for the cuttability by performing a cold expansion step in the following manner. Specifically, a lamination apparatus (device name: DFM 2800) manufactured by DISCO was used to adhere the dicing die bonding film 20 to the plurality of semiconductor chips 30a having a thickness of 30 μm obtained by the above method so that the adhesive layer 3 exposed by peeling the release liner from the dicing die bonding film 20 manufactured in each of examples and comparative examples was adhered to the surface opposite to the surface to which the back surface grinding tape was adhered, and an annular frame (wafer ring) 40 was adhered to the exposed portion of the adhesive layer 2 at the outer edge portion of the dicing tape 10 under the conditions that the lamination temperature was 70 ℃ and the lamination speed was 10 mm/sec. Then, the back grinding tape is peeled off, and the plurality of semiconductor chips 30a are transfer-fixed to the die bonding film 3 of the dicing die bonding film 20. Here, the dicing die bonding film 20 is attached to the semiconductor chips 30a, which are the divided bodies of the semiconductor wafer 30, so that the MD direction of the base film 1 coincides with the longitudinal direction of the lattice-shaped dividing lines of the semiconductor wafer 30 (the TD direction of the base film 1 coincides with the transverse direction of the lattice-shaped dividing lines of the semiconductor wafer 30).

The laminate (the plurality of semiconductor chips 30 a/the adhesive layer 3/the adhesive layer 2/the base material film 1) including the plurality of semiconductor chips 30a held by the annular frame (wafer ring) 40 is fixed to an expansion device (device name: DDS2300 fully automatic chip separator) manufactured by DISCO corporation. Next, the dicing tape 10 (adhesive layer 2/base material film 1) accompanying dicing of the die bonding film 20 of the semiconductor wafer 30 is cold-expanded under the following conditions, whereby the adhesive layer 3 is cut. Thereby, the semiconductor chip 30a with the die bonding film (adhesive layer) 3 is obtained. In this example, the cold expansion step is performed under the following conditions, but the cold expansion step may be performed after the expansion conditions (such as "expansion rate" and "expansion amount") are appropriately adjusted according to the physical properties of the base film 1, the temperature conditions, and the like.

Conditions of the cold expansion step

(1) Temperature: -15 ℃, cooling time: 80 seconds

(2) Expansion rate: 200 mm/sec

(3) Expansion amount: 11mm

(4) Standby time: 0 seconds

The number of sides that were not cut out among the sides to be cut out was measured by observing the adhesive layer 3 after cold expansion from the front surface side of the semiconductor chip 30a at a magnification of 200 times using an optical microscope (form: VHX-1000) manufactured by Keyence, inc. Then, for each adhesive layer 3, the ratio of the number of the cut sides to the total number of the planned cut sides was calculated from the total number of the planned cut sides and the total number of the non-cut sides as a cut rate (%). The observation with the optical microscope is performed for the total number of the semiconductor chips 30a. The adhesive layers 3 were evaluated for the cuttability according to the following criteria, and the evaluation of B or more was determined to be good in the cuttability.

A: the cutting rate is 95% to 100%.

B: the cutting rate is more than 90% and less than 95%.

C: the cutting rate is less than 90%.

5.2.2 confirmation of relaxation removal of dicing tape 10 after the thermal shrinkage step

After the cold expansion state was released, an expansion device (device name: DDS2300 fully automatic chip separator) manufactured by DISCO corporation was used again, and the normal temperature expansion process was performed in the thermal expansion unit under the following conditions.

Conditions of the normal temperature expansion step

(1) Temperature: 23 DEG C

(2) Expansion rate: 30 mm/sec

(3) Expansion amount: 9mm of

(4) Standby time: 15 seconds

Next, the dicing tape 10 is sucked by the suction base while maintaining the inflated state, and the suction base is lowered together with the workpiece while maintaining the suction by the suction base. Then, a heat shrinkage step is performed under the following conditions to heat-shrink (heat-shrink) the peripheral portion of dicing tape 10 outside the holding area of semiconductor chip 30 a. The surface temperature of the heated portion of the dicing tape 10 was 80 ℃.

Conditions of the thermal shrinkage step

(1) Hot air temperature: 220 DEG C

(2) Air volume: 40L/min

(3) Distance between hot air outlet and dicing tape 10: 20mm of

(4) Rotational speed of the pedestal: 7 DEG/sec

Next, after the dicing tape 10 was released from the suction by the suction mount, the work was removed from the expansion device, placed on a flat rubber pad, and the degree of elimination of the slack in the peripheral portion of the dicing tape 10 outside the holding area of the semiconductor chip 30a after heat shrinkage (heat shrinkage) was visually confirmed under a three-wavelength fluorescent lamp. The degree of relaxation elimination was evaluated for each dicing tape 10 based on the following criteria, and the evaluation of B or more was judged to be good in heat shrinkage.

A: no relaxation was confirmed.

B: although little part of the wrinkle-like relaxation was confirmed, it was slight.

C: clearly, the loose or deformed wrinkles were confirmed.

5.2.3 confirmation of incision width after thermal shrinkage Process

After the heat shrinkage step, the work was removed from the expansion device, and the dicing tape 10 in the dicing die bonding film 20 was evaluated for expansibility and heat shrinkage by measuring the distance (kerf width) between adjacent semiconductor chips 30a from the front surface side of the semiconductor wafer 30 at a magnification of 200 times using an optical microscope (form: VHX-1000) manufactured by Keyence, inc.

Specifically, for 4 sites of one divided reticle portion formed by the adjacent 4 semiconductor chips 30a in the center portion 31 of the semiconductor wafer 30 shown in fig. 13 (MD direction of the base material film 1: at 2 of the cuts MD1 and MD2, the TD direction of the base film 1, the 2 of the cuts TD1 and TD2, refer to fig. 14), the 7 of the two dicing cross portions formed by the adjacent 6 semiconductor chips 30a in the left portion 32 (MD direction, 3 of the cuts MD3 to MD5, TD direction, 4 of the cuts TD3 to TD6, not shown), the 7 of the two dicing cross portions formed by the adjacent 6 semiconductor chips 30a in the right portion 33 (MD direction, 3 of the cuts MD6 to MD8, TD direction, 4 of the cuts TD7 to TD10, not shown), the 7 of the two dicing cross portions formed by the adjacent 6 semiconductor chips 30a in the upper portion 34 (MD direction, 4 of the cuts MD9 to MD12, TD direction, 3 of the cuts TD11 to TD13, not shown), and the average value of the two dicing cross portions formed by the adjacent 6 semiconductor chips 30a in the lower portion 33 (MD direction, 3 to MD direction, 16) in the MD direction, and TD direction, 16 to MD direction, and 16 to TD direction, respectively, are calculated as the average value of the width of the cuts between the adjacent 6 to MD directions, 16, and the cut directions, and the average value of the cut directions, and the cut directions, 16, respectively, is calculated. The dicing tape 10 in the dicing die-bonding film 20 was evaluated for the expansibility and the heat shrinkability based on the following criteria, and the evaluation of B or more was judged to be good for the expansibility and the heat shrinkability, that is, the slit width was ensured to such an extent that the problem was not liable to occur in the pick-up process.

A: the MD slit width and the TD slit width are both 30 μm or more.

B: the MD slit width is 30 μm or more, and the TD slit width is 25 μm or more and less than 30 μm; alternatively, the TD slit width has a value of 30 μm or more and the MD slit width has a value of 25 μm or more and less than 30 μm; alternatively, the MD slit width and the TD slit width are both 25 μm or more and less than 30 μm; any one of them.

C: at least one of the values of the MD slit width and the TD slit width is smaller than 25 μm.

5.2.4 evaluation of pickup of dicing tape 10 in dicing die-bonding film 20

The irradiation intensity was 70mW/cm from the side of the base film 1 of the dicing tape 10 holding the semiconductor chips 30a with the die bonding films (adhesive layers) 3a diced by the above-mentioned expansion step ² At an accumulated light quantity of 150mJ/cm ² Ultraviolet (UV) light having a center wavelength of 365nm was irradiated to cure the adhesive layer 2, thereby obtaining a sample for evaluating the pickability.

Next, a pickup test was performed using a device (device name: die binder DB-830P) having a pickup mechanism, manufactured by Fasford Technology Co., ltd., hitachi, inc. The dimensions of the pickup collet were set to 4.4x6.9 mm, the number of pins of the push-up pin was set to 12, the push-up speed of the push-up pin was set to 10 mm/sec, and the push-up height of the push-up pin was set to 100 μm with respect to the conditions of pickup. The number of samples to be tested to be picked up was set to 20 (chips) at a predetermined position, and the pickability of the dicing tape 10 in the dicing die-bonding film 20 was evaluated based on the following criteria, and the evaluation of B or more was judged to be good pickability.

A: the number of 20 chips (number of successful pickup) without chip breakage or pickup errors was 20. The pick-up success rate is 100%.

B: the number of 20 chips successively picked up without chip breakage or pickup errors (pickup success number) was 19. The pick-up success rate is 95%.

C: the number of chips (pickup success number) in which 20 chips were picked up successively without chip breakage or pickup errors was 18 or less. The pick-up success rate is less than 90%.

6. Evaluation results

The results of the evaluations of the dicing die-bonding films 20 (DDF (a) to DDF (j), DDF (l) to DDF (dd)) produced in examples 1 to 23 and comparative examples 1 to 6 are shown in tables 1 to 5 together with the components of the dicing die-bonding film 20 (the type of adhesive composition, the shear viscosity, and the thicknesses of the adhesive layer and the adhesive layer) and the components of the base film 1 used (the content ratio of methacrylic acid and isobutyl acrylate in the ionomer resin used in each resin layer, the zinc ion concentration, and the vicat softening temperature and thickness of the resin used in each resin layer as a whole).

TABLE 1

TABLE 2

TABLE 3 Table 3

TABLE 4 Table 4

TABLE 5

First, as shown in tables 1 to 4, dicing die bonding films (DDF (a) to DDF (j), DDF (l) to DDF (x)) of examples 1 to 23 using an adhesive tape for wafer processing satisfying the requirements of the present invention were cut off, and after the adhesive layer was cut off, the semiconductor chips with the adhesive layer were fixed to the adhesive layer of the adhesive tape for wafer processing (dicing tape) with the dicing width sufficiently ensured, and as a result, good pick-up was confirmed. That is, since the dicing die bonding film using the adhesive tape for wafer processing of the present invention uses, as the base film, a resin film having a resin layer comprising an ionomer resin in which an ethylene-unsaturated carboxylic acid copolymer containing constituent units derived from an unsaturated carboxylic acid in a specific content ratio is crosslinked with zinc ions at a specific concentration and which has an appropriate vicat softening temperature, the adhesive film can be satisfactorily cut by expansion with moderate tensile stress at the time of expansion and uniform expansion and shrinkage in the heat shrinkage step, and can be thermally shrunk to remove slack generated in the tape at the time of expansion. The results were found to be: since the dicing width between the adhesive layer-attached semiconductor chips secured by the expansion is properly maintained, damage due to the contact between the chips and re-adhesion due to the contact between the adhesive layers become less likely to occur, and therefore the adhesive layer-attached semiconductor chips can be picked up well. Moreover, it is known that: even if an adhesive layer having a high fluidity and a large thickness typified by a wire-embedded die bonding film is used as the adhesive layer, the adhesive layer can be cut well as in a general-purpose die bonding film, and a semiconductor chip with the adhesive layer can be picked up well.

With respect to the examples, detailed comparisons can be found: first, when comparing dicing die-bonding films of examples 1 to 15 in which the total thickness of the resin layers (first resin layer, second resin layer, and third resin layer) containing the specific ionomer resin at a content ratio of 80 mass% or more, in each resin layer, was 100% of the total thickness of the base film, zinc (Zn ²⁺ ) Examples 2 to 8, examples 12, 13 and example 15, in which the ion concentration was in the range of 0.41mmol to 0.60mmol, were superior to zinc (Zn) per 1g of the ethylene-unsaturated carboxylic acid-based copolymer in evaluation of the severance of the adhesive layer, the kerf width after heat shrinkage and the pick-up property ²⁺ ) The die-bonding films of example 1, examples 9 to 11 and example 14 had ion concentrations of 0.38 mmol. In addition, zinc (Zn) per 1g of ethylene-unsaturated carboxylic acid copolymer ²⁺ ) The dicing die-bonding films of examples 12 and 13, in which the content of the constituent unit (isobutyl acrylate) derived from the unsaturated carboxylic acid ester in the ethylene-unsaturated carboxylic acid-based copolymer was as low as 1.5 mass%, were slightly inferior to those of examples 2 to 8 and 15, in which the content of isobutyl acrylate in the ethylene-unsaturated carboxylic acid-based copolymer was 5 mass% or more, although the ion concentration was in the range of 0.41 to 0.60 mmol.

From the evaluation results of the dicing die-bonding films of example 2, examples 20 to 22, and example 23, in which dicing tape 10 was used, the dicing die-bonding films having the same composition but different shear viscosity characteristics at 80 ℃ were thickened to 50 μm with respect to 30 μm of example 3, it was found that: even if any of the die bonding film (adhesive layer) of the wire-embedded die bonding film and the general-purpose die bonding film is used, the dicing property of the adhesive layer is generally good, the slit width after heat shrinkage is sufficiently ensured, and the pick-up property is also good.

Further, it was found that: the dicing die-bonding film of example 16 having the substrate film of 2 resin 3 layer structure using the ionomer resin (IO-2) as the resin composition for the first resin layer and the second resin layer and using the resin (IO-2/PA) obtained by mixing the ionomer resin and the polyamide resin in a mass ratio of 90:1 as the substrate film of 2 resin 3 layer structure for the third resin layer was as excellent as the dicing die-bonding film of example 2 having the substrate film of 1 resin 3 layer structure using only the ionomer resin (IO-2), but the dicing die-bonding film of example 17 having the substrate film of 2 resin 2 layer structure using the ionomer resin (IO-2) as the resin composition for the first resin layer and using the resin (IO-2/TPO-1) obtained by mixing the ionomer resin and the olefin thermoplastic elastomer resin in a mass ratio of 80:20 was slightly inferior to the dicing die-bonding film of example 2, although it was not problematic in practical use.

Further, the dicing die-bonding film of example 19, which has a substrate film of 2 resin 3 layer structures using an ionomer resin (IO-2) as the resin composition for the first resin layer and the third resin layer, a substrate film of 2 resin 3 layer structures using an olefin-based thermoplastic elastomer resin (TPO-1) as the resin composition for the second resin layer, and a total thickness of the resin layers containing the specific ionomer resin at a content ratio of 80 mass% or more was 89% of the total thickness of the substrate film, and the dicing die-bonding film of example 18, which has a resin composition for the first resin layer and the second resin layer using an ionomer resin (IO-2), a substrate film of 2 resin 3 layer structures using an olefin-based thermoplastic elastomer resin (TPO-2) as the resin composition for the third resin layer, and a total thickness of the resin layers containing the specific ionomer resin at a content ratio of 80 mass% or more was 67% of the total thickness of the substrate film, were slightly inferior results compared with the dicing die-bonding film of example 2, although they were practically unproblematic.

In contrast, as shown in table 5, it was confirmed that: dicing die bonding films (DDF (y) to DDF (dd)) of comparative examples 1 to 6 using an adhesive tape for wafer processing that did not satisfy the requirements of the present invention were inferior to those of examples 1 to 23 in evaluation of the severability of the adhesive layer, the kerf width after heat shrinkage, and the pick-up property.

Specifically, it is intended to use only zinc (Zn) per 1g of an ethylene-unsaturated carboxylic acid copolymer ²⁺ ) The dicing die-bonding film of comparative example 1, which is a base film of 1 resin 3 layer structure having an ionomer resin (IO-16) with an ion concentration of less than 0.38mmol, has a low tensile stress, and is inferior to the dicing die-bonding films of examples 1 to 15 in terms of the dicing property of the adhesive layer, and also insufficient in terms of shrinkage upon heat shrinkage, and thus the dicing width cannot be sufficiently ensured.

In addition, the composition comprises zinc (Zn) in an amount of less than 6.9 mass% based on 1g of the ethylene-unsaturated carboxylic acid copolymer, wherein the content of the constituent unit (methacrylic acid) derived from the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer is used alone ²⁺ ) The dicing die-bonding film of comparative example 2, which was a substrate film of 1 resin 3 layer structure having an ion concentration of less than 0.38mmol of the ionomer resin (IO-17), was also inferior in pickup property to the dicing die-bonding films of examples 1 to 15, similarly to the dicing die-bonding film of comparative example 1.

Further, the composition contains zinc (Zn) in an amount of more than 18.0 mass% based on 1g of the ethylene-unsaturated carboxylic acid copolymer, wherein the content of the constituent unit (methacrylic acid) derived from the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer is used alone ²⁺ ) The dicing die-bonding film of comparative example 3, which was a substrate film of 1 resin 3 layer structure of ionomer resin (IO-18) having an ion concentration of less than 0.38mmol and a vicat softening temperature of less than 50 ℃, was inferior in pick-up properties to the dicing die-bonding films of examples 1 to 15, similarly to the dicing die-bonding film of comparative example 1. In the dicing tape processing, since partial blocking occurs on the core side of the raw roll, evaluation was performed at a portion free from blocking.

Further, the composition comprises zinc (Zn) in an amount of less than 6.9 mass% based on 1g of the ethylene-unsaturated carboxylic acid copolymer, wherein the content of the constituent unit (methacrylic acid) derived from the unsaturated carboxylic acid in the ethylene-unsaturated carboxylic acid copolymer is only used ² ⁺ ) The dicing die-bonding film of comparative example 4, which is a base film of 1 resin 3 layer structure of an ionomer resin (IO-19) having an ion concentration of less than 0.38mmol and a vicat softening temperature of more than 80 ℃, is presumed to be a film that causes a necking phenomenon at the time of inflation, and is inferior in pick-up properties to the dicing die-bonding films of examples 1 to 15 because the cutting property of the adhesive layer and the ensuring of the slit width are insufficient due to insufficient expansibility, and the shrinking property at the time of heat shrinkage is also insufficient and the slit width is not sufficiently ensured.

Further, the resin composition comprises a resin layer formed of an ethylene-methacrylic acid copolymer (EMAA) having a Vicat softening temperature of 80 ℃ or higher and zinc (Zn) laminated on the resin layer per 1g of the ethylene-unsaturated carboxylic acid copolymer ²⁺ ) The dicing die-bonding film of comparative example 6, which was a 2-resin 2-layer substrate film having a resin layer formed of an ionomer resin (IO-16) having an ion concentration of less than 0.38mmol, was inferior in pick-up properties to the dicing die-bonding films of examples 1 to 23, similarly to the dicing die-bonding film of comparative example 1.

In comparative example 5, since stable film formation of the base film 1 (y) was not performed, evaluation as dicing die bonding film was not performed.

Description of symbols

1, a base material film, wherein the base material film,

2 a layer of adhesive agent, which is provided with a layer of adhesive agent,

3,3a1,3a2, die bonding films (adhesive layers, adhesive films),

4 a support substrate for mounting a semiconductor chip,

5 an external connection terminal, which is connected to the external connection terminal,

6, a terminal is arranged on the upper surface of the connecting rod,

7, a lead wire is arranged on the upper surface of the substrate,

8, a sealing material is adopted to seal the inner wall of the container,

9 a support member for the support of the vehicle,

10, cutting the adhesive tape,

an OPP film base material single-sided adhesive tape (backing tape),

12, paper double-sided tape (fixing tape),

13 is a flat-plate cross pedestal,

14, adhering adhesive tape (backing adhesive tape and fixing adhesive tape) on one side of the PET film substrate,

15: a SUS plate,

20 dicing the die-bonding film,

w,30 is a semiconductor wafer,

30a,30a1,30a2,

30b, a modified region,

31 a central portion of the semiconductor wafer,

32 the left portion of the semiconductor wafer,

33 the right portion of the semiconductor wafer,

34-the upper portion of the semiconductor wafer,

35 a lower portion of the semiconductor wafer,

40 a ring frame (wafer ring),

41 a holding member which is provided with a plurality of holding members,

50 parts of an adsorption jacket,

60 push-up pins (needles),

70,80, semiconductor device.

Claims

1. An adhesive tape for wafer processing, which is used when an adhesive layer is cut along a chip by expansion, and which has a base film and an adhesive layer provided on the base film,

the ionomer resin is formed of a resin containing an ethylene-unsaturated carboxylic acid copolymer as a matrix polymer of the resin and zinc ions, and having a Vicat softening temperature defined in JIS K7206 within a range of 50 ℃ as a lower limit and 79 ℃ as an upper limit,

2. The adhesive tape for wafer processing according to claim 1,

3. The adhesive tape for wafer processing according to claim 1 or 2,

4. The adhesive tape for wafer processing according to any one of claim 1 to 3,

5. The adhesive tape for wafer processing according to any one of claims 1 to 4,

6. An adhesive tape for wafer processing comprising an adhesive layer detachably provided on the adhesive layer of the adhesive tape for wafer processing according to any one of claims 1 to 5.

7. The adhesive tape for wafer processing according to claim 6,

8. The adhesive tape for wafer processing according to claim 6 or 7,

9. The adhesive tape for wafer processing according to claim 8,

10. A method for manufacturing a semiconductor chip or a semiconductor device, using the adhesive tape for wafer processing according to any one of claims 1 to 9.