CN113755111A - Substrate film for dicing tape and dicing tape - Google Patents

Abstract

The invention provides a base material film for a dicing tape and the dicing tape, which can inhibit the generation of cutting chips in a dicing process and improve the pickup property in a pickup process. The base film of the present invention is a base film for dicing tape, having a 1 st surface on which an adhesive layer is formed and a 2 nd surface opposite thereto, and is composed of a resin containing a thermoplastic polyester elastomer, the thermoplastic polyester elastomer being a block copolymer containing a hard segment (a) mainly composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol or alicyclic diol, and a soft segment (B) mainly composed of an aliphatic polyether, and has a flexural modulus (G') at 23 ℃ in the range of 10 to 135MPa when dynamic viscoelasticity is measured in a clamped-end bending mode under conditions of a frequency of 1Hz and a temperature rise rate of 0.5 ℃/min.

Description

Substrate film for dicing tape and dicing tape

Technical Field

The present invention relates to a base film for a dicing tape for fixing a semiconductor wafer when the semiconductor wafer is diced into chip-like elements, and a dicing tape using the base film.

Background

Conventionally, in the manufacture of semiconductor devices, in order to singulate semiconductor wafers into semiconductor chips through a dicing (hereinafter, sometimes simply referred to as "cutting" or "dicing") process, dicing tapes and dicing die attach films formed by integrating the dicing tapes and the die attach films are sometimes used. The dicing tape is provided with an adhesive layer on a base film, and is used for placing a semiconductor wafer on the adhesive layer, and fixing and holding singulated semiconductor chips to prevent the chips from scattering when dicing the semiconductor wafer. Then, the semiconductor chip is peeled off from the adhesive layer of the dicing tape, and fixed to an adherend such as a lead frame or a wiring board with a separately prepared adhesive or adhesive film.

The dicing die attach film is a material in which a die attach film (hereinafter, sometimes referred to as "adhesive film" or "adhesive layer") is provided on an adhesive layer of a dicing tape so as to be peelable. In the manufacture of semiconductor devices, a semiconductor wafer is held on a die attach film of a dicing die attach film, and the semiconductor wafer is diced together with the die attach film to obtain semiconductor chips each having an adhesive film. Then, the semiconductor chip is peeled from the adhesive layer of the dicing tape as a semiconductor chip with a die attach film together with the die attach film, and the semiconductor chip is fixed to an adherend such as a lead frame or a wiring board via the die attach film.

After the semiconductor chip or the semiconductor chip with the die attach film as described above is obtained, the semiconductor wafer held on the adhesive layer surface of the dicing tape and on the die attach film surface of the dicing die attach film may be subjected to dicing with a blade. In the dicing with the blade, the semiconductor wafer or the die attach film of the semiconductor wafer and the dicing die attach film holding the semiconductor wafer is cut by a dicing blade rotating at a high speed, and is singulated into semiconductor chips of a predetermined size or semiconductor chips with an adhesive film. In the blade dicing step, in order to remove chips and the like which are inevitably generated, cutting work is performed while supplying running water to the dicing blade and the semiconductor wafer.

In such a blade dicing step, in order to accurately obtain semiconductor chips or semiconductor chips with an adhesive film from a large-diameter semiconductor wafer workpiece, a so-called full-cut method of completely cutting and dividing them is preferable, but actually, in consideration of the operation accuracy of the apparatus, the thickness accuracy of the dicing tape, the chip bonding film, and the semiconductor wafer used, the cutting depth of the dicing blade that cuts into the semiconductor wafer or the like from the side opposite to the dicing tape may reach the base material film of the dicing tape. In this case, a filiform cutting chip may be generated during cutting. On the other hand, it is considered that frictional heat is generated in a portion of the base material which is in contact with the cutter blade rotating at a high speed, and the base material constituent material softened and melted by the frictional heat is elongated by the drawing action from the cutter blade rotating at a high speed, thereby generating the cutting chips in a filament shape.

The filament-like chips often adhere to the semiconductor chips subjected to the dicing step under the supply of running water. If the chips in the form of silk chips are attached to the semiconductor chip all the time, the following problems arise: the reliability of the semiconductor element is lowered, the semiconductor chip cannot be picked up accurately due to a recognition error occurring in the pickup process, the semiconductor chip is broken and cannot be picked up, or the picked-up semiconductor chip cannot be mounted in a correct orientation with high accuracy. Therefore, in the blade cutting step, it is desired that the amount of the filiform chips generated is small.

As a prior art for suppressing the generation of cutting chips, cited document 1 discloses an adhesive tape for dicing, which is formed by laminating a resin layer having an MFR (melt mass flow rate) of 3 or less at a test temperature of 190 ℃ and containing a constituent having a carboxyl group as a constituent of a polymer and an adhesive layer, with the object of providing an adhesive tape for dicing that can prevent the cutting chips from remaining on the surface of a semiconductor wafer in a full-cut dicing system. Further, patent document 2 discloses a dicing base film having a layer containing a resin containing an aromatic polyamide for the purpose of providing a dicing base film and a dicing film which hardly generate chips in a dicing process of a semiconductor wafer or the like.

On the other hand, in recent years, with the spread of IC cards and the rapid increase in capacity of USB memories, the number of stacked semiconductor chips increases, and further thinning of the semiconductor chips is desired. Therefore, it is necessary to reduce the thickness of the conventional semiconductor chip to about 200 to 350 μm to 50 to 100 μm or less. In addition, in order to achieve further cost reduction, it is strongly required to produce semiconductor chips with as high productivity and high yield as possible, and maximum efficiency is also required in each step of the manufacturing process of a semiconductor device.

However, silicon, glass, or the like used as a semiconductor chip is a brittle material, and if the thickness of the semiconductor chip is reduced as described above, the risk of breakage during transportation or processing becomes higher. For example, as one of the manufacturing processes of a semiconductor device, there is a process of picking up a singulated semiconductor chip or a semiconductor chip with an adhesive film, but if the thickness of the semiconductor chip is reduced, the semiconductor chip is easily broken at the time of picking up. In the picking-up step, a method is mainly used in which the semiconductor chip or the semiconductor chip with the adhesive film is picked up from the adhesive layer of the dicing tape by sucking the semiconductor chip or the semiconductor chip with the adhesive film from above with a suction collet while pushing up the diced semiconductor chip or the semiconductor chip with the adhesive film from the base material film side of the dicing tape by a push-up pin (needle) or the like to assist the peeling of the semiconductor chip or the semiconductor chip with the adhesive film from the adhesive layer. In this case, if it is difficult to assist the peeling of the semiconductor chip or the semiconductor chip with the adhesive film from the adhesive layer when the semiconductor chip or the semiconductor chip with the adhesive film is pushed up, it is considered that the pushing-up height (pushing-up amount) needs to be further increased to facilitate the peeling, and as a result, the stress applied to the semiconductor chip becomes larger, the warpage of the semiconductor chip becomes larger, and cracking occurs.

Therefore, at present, a countermeasure is taken such as reducing or adjusting the speed of pushing up the push-up pins (needles) to an appropriate speed, and carefully picking up the thin film semiconductor chips while adjusting the degree of pushing up. However, it is still not considered that the reduction in yield due to the breakage of the semiconductor chip in the pickup process is sufficiently solved, and since it largely depends on the kind of the dicing tape, it is strongly desired to further improve the dicing tape together with the pickup mechanism. Specifically, a dicing tape capable of picking up a thin film semiconductor chip without damage at a push-up speed within a range allowable in practical use and at a smaller push-up height is desired.

As a prior art for improving the pickup property, cited document 3 discloses a dicing tape having an adhesive layer on a base film having a ring stiffness of 3 to 25mN measured under predetermined conditions, for the purpose of providing a dicing tape capable of efficiently picking up a thin semiconductor chip in a pickup step after a dicing step. Further, patent document 4 discloses a film made of a polyester block copolymer in which a specific hard segment component and a specific soft segment component are combined, for the purpose of providing an antistatic film having both good stretching properties and good pickup properties, which is used in the production of semiconductor devices.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 9-8111

Patent document 2: japanese patent laid-open publication No. 2016-31996

Patent document 3: japanese laid-open patent publication No. 2010-225753

Patent document 4: japanese patent laid-open No. 2006 and 152072

Disclosure of Invention

Problems to be solved by the invention

The adhesive tape for fixing a semiconductor wafer of cited document 1 uses a resin having a high melt viscosity as a base film, and thus surely suppresses the generation of chips in the dicing step, but does not particularly mention the pick-up characteristics of thin-film semiconductor chips. The ethylene-methacrylic acid copolymer and the ethylene-methacrylic acid- (2-methylpropylacrylate) -3-membered copolymer resin, which are the materials of the base film exemplified in the examples, are slightly hard materials because of their high melt viscosity, and the pickup characteristics may be insufficient when the semiconductor chip is thin.

Further, with the dicing film of cited document 2, the generation of cutting chips in the dicing process is surely suppressed, but the pickup characteristics of the thin film semiconductor chip are not particularly mentioned. The aromatic polyamide as the main component of the material of the base film exemplified in the examples is a material having a high melting point and is hard, and therefore, when the semiconductor chip is thin, the pickup characteristics may or may not be sufficient.

On the other hand, the dicing tape of cited document 3 is considered to have a certain effect of improving the pick-up property of the semiconductor chip having a thickness of 100 μm in the example, but there is still room for improvement (reduction) in the push-up height (pin height) at the time of pick-up. Although there is no particular mention of suppressing the generation of cutting chips in the dicing step, the resins exemplified in examples as the material of the base film, such as ethylene-vinyl acetate and ethylene-methacrylic acid copolymer having a large MFR, have a slightly low melting point and may be insufficient for suppressing the generation of cutting chips in the dicing step.

Further, the film for fixing a semiconductor wafer of cited document 4 is considered to be excellent in the pickup property of the semiconductor chip having a thickness of 350 μm in the example, but the pickup property and the specific contents thereof when applied to the semiconductor chip having a thickness of 100 μm or less are not described in detail. Further, there is no particular mention of suppressing the generation of chips in the cutting process.

In this way, when the dicing tape of the related art is applied to a semiconductor wafer having a thickness of 100 μm or less, it is difficult to say that the dicing tape is sufficiently satisfactory from the viewpoint of both suppressing the generation of chips in the dicing step and improving the pick-up property in the pick-up step, and there is still room for improvement.

The present invention has been made in view of the above problems and circumstances, and an object thereof is to provide a base material film for dicing tape and a dicing tape using the base material film, which can suppress the generation of chips in a dicing step and improve the pickup property in a pickup step, in a range where there is no problem in practical use, even when applied to a semiconductor wafer having a thickness of 100 μm or less.

Means for solving the problems

That is, the present invention provides a base material film for dicing tape, having a 1 st face on which an adhesive layer is formed and a 2 nd face opposite thereto,

comprising a resin containing a thermoplastic polyester elastomer which is a block copolymer comprising a hard segment (A) mainly composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol or an alicyclic diol, and a soft segment (B) mainly composed of an aliphatic polyether,

the base film has a flexural modulus (G') at 23 ℃ in the range of 10MPa to 135MPa when the dynamic viscoelasticity is measured in a clamped beam bending mode at a frequency of 1Hz and a temperature rise rate of 0.5 ℃/min.

In one embodiment, the base film has a flexural modulus (G') at 23 ℃ in a range of 17MPa to 115 MPa.

In one embodiment, the soft segment (B) has a content (copolymerization amount) in a range of 51 mass% to 73 mass% with respect to the total mass of the hard segment (a) and the soft segment (B).

In one embodiment, the soft segment (B) has a content (copolymerization amount) in a range of 55 mass% to 70 mass% with respect to the total mass of the hard segment (a) and the soft segment (B).

In a certain mode, the hard segment (a) is polybutylene terephthalate (PBT).

In one embodiment, the soft segment (B) is an ethylene oxide addition polymer of poly (oxytetramethylene) glycol (PTMG) and/or poly (propylene oxide) glycol (PPG-EO addition polymer).

In one embodiment, the base film is composed of a single resin layer, and the resin including the thermoplastic polyester elastomer constituting the layer has a crystal melting point in a range of 160 ℃ to 200 ℃.

In one embodiment, the base film is composed of a plurality of resin layers laminated, and the resin including the thermoplastic polyester elastomer constituting the layer having the 1 st surface has a crystal melting point in a range of 160 ℃ to 200 ℃.

In one embodiment, the substrate film has a thickness in a range of 70 μm to 155 μm.

In one embodiment, the elongation of the base film is in a range of 300% to 700%.

Further, the present invention provides a dicing tape having the base material film of any one of the above and an adhesive layer formed on a surface thereof.

Effects of the invention

According to the present invention, it is possible to provide a base material film for dicing tape that can suppress the generation of chips in the dicing step and improve the pickup property in the pickup step, in a range that does not cause any problem in practical use, even when applied to a semiconductor wafer having a thickness of 100 μm or less. Further, a dicing tape using the above substrate film can be provided.

Drawings

Fig. 1(a) to (d) are cross-sectional views showing an example of the structure of a base film for dicing tape applied to the present embodiment.

Fig. 2 is a cross-sectional view showing an example of a structure of a dicing tape using a base material film for a dicing tape applied to the present embodiment.

Fig. 3 is a cross-sectional view showing an example of a structure in which a dicing tape using a base material film for a dicing tape applied in the present embodiment is bonded to a die attach film.

FIG. 4 is a flowchart for explaining a method of manufacturing a dicing tape.

Fig. 5 is a flowchart for explaining a method for manufacturing a semiconductor chip.

Fig. 6 is a perspective view showing a state in which a ring frame (wafer ring) is attached to an outer edge portion of a dicing tape (or dicing die attach film) and a semiconductor wafer is attached to a central portion thereof.

[ FIG. 7] (a) to (f) are sectional views showing examples of manufacturing semiconductor chips using dicing tapes.

[ FIG. 8] (a) to (f) are sectional views showing examples of manufacturing a semiconductor chip using a dicing die attach film.

Description of the symbols

1 … base film, 2 … adhesive layer, 3 … die attach film (adhesive layer), 10 … dicing tape, 20 … dicing die attach film, 30 … semiconductor wafer, 30a … semiconductor chip, 40 … ring frame, 50 … adsorption collet, 60 … push-up pin (needle)

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings as necessary. However, the present invention is not limited to the following embodiments.

Constitution of base film and dicing tape

Fig. 1(a) to (d) are cross-sectional views showing an example of the structure of the base film 1 for dicing tape applied to the present embodiment. The base film 1 of the present embodiment may be a single layer of a single resin (see fig. 1(a) 1-a), may be a laminate composed of a plurality of layers of the same resin (see fig. 1(B) 1-B), or may be a laminate composed of a plurality of layers of different resins (see fig. 1(C) 1-C, (D) 1-D). When a multilayer body composed of a plurality of layers is formed, the number of layers is not particularly limited, and is preferably in the range of 2 to 5 layers.

Fig. 2 is a cross-sectional view showing an example of a structure of a dicing tape using the base film 1 for dicing tape applied to the present embodiment. As shown in fig. 2, the dicing tape 10 has a structure in which an adhesive layer 2 is provided on the 1 st surface of a base film 1. Although not shown, a base sheet (release liner) having releasability may be provided on the surface (the surface opposite to the surface facing the base film 1) of the adhesive layer 2 of the dicing tape 10. As the adhesive for forming the adhesive layer 2, for example, an active energy ray-curable acrylic adhesive or the like, which is cured and shrunk by irradiation with an active energy ray such as Ultraviolet (UV) and the like, and the adhesive force to an adherend is reduced, can be used.

In a semiconductor manufacturing process, the following is used. After the semiconductor wafer is held on the adhesive layer 2 of the dicing tape 10 (temporarily fixed) and the semiconductor wafer is diced (cut) to produce individual semiconductor chips, the semiconductor chips are peeled off from the adhesive layer 2 of the dicing tape 10. The obtained semiconductor chip is fixed to an adherend such as a lead frame or a wiring board via a separately prepared adhesive.

Fig. 3 is a cross-sectional view showing an example of a dicing die attach film, which is a structure in which a dicing tape 10 using a base film 1 for dicing tape applied in the present embodiment is bonded and integrated with a die attach film (adhesive layer) 3. As shown in fig. 3, the dicing die attach film 20 has a structure in which a die attach film (adhesive layer) 3 is releasably adhered to and laminated on the adhesive layer 2 of the dicing tape 10.

In a semiconductor manufacturing process, the following is used. After the semiconductor wafer is held (bonded) on the die attach film 3 of the dicing die attach film 20 and the semiconductor wafer is diced to produce individual semiconductor chips, the semiconductor chips are peeled together with the die attach film (adhesive layer) 3 from the adhesive layer 2 of the dicing tape 10. The obtained semiconductor chip with the die attach film (adhesive layer) 3 is fixed to an adherend such as a lead frame or a wiring board via the die attach film (adhesive layer) 3. Although not shown, a base sheet (release liner) having releasability may be provided on each of the surface of the adhesive layer 2 (the surface opposite to the surface facing the base film 1) and the surface of the die attach film 3 (the surface opposite to the surface facing the adhesive layer 2) of the dicing tape 10.

Base film

The base film 1 of the present embodiment is made of a resin containing a thermoplastic polyester elastomer. The thermoplastic polyester elastomer is contained in an amount of preferably 80 mass% or more, more preferably 90 mass% or more, of the total amount of the resins constituting the base film 1. First, the following description will be made of a thermoplastic polyester elastomer as a main component of the resin constituting the base film 1.

< thermoplastic polyester elastomer >

The thermoplastic polyester elastomer is a polyester-polyether type thermoplastic elastomer which is a block copolymer comprising a hard segment (a) mainly comprising a polyester comprising an aromatic dicarboxylic acid and an aliphatic diol or an alicyclic diol, and a soft segment (B) mainly comprising an aliphatic polyether as constituent components of the copolymer. The phrase "comprising a unit of a main component" means that the "polyester composed of an aromatic dicarboxylic acid and an aliphatic diol or alicyclic diol" accounts for 75 mass% or more, preferably 80 mass% or more, and particularly preferably 90 mass% or more of the total amount of the hard segments (a). Similarly, the "aliphatic polyether" accounts for 75% by mass or more, preferably 80% by mass or more, and particularly preferably 90% by mass or more of the total amount of the soft segment (B).

As described above, one of preferable characteristics for suppressing the generation of the cutting chips in a filament shape at the time of cutting is a high melting point of the base film 1. On the other hand, one of preferable characteristics for improving the pick-up property of the thin-film semiconductor chip is flexibility of the base film 1. However, these two characteristics are generally a trade-off relationship in most cases. That is, if the melting point of the base film 1 is to be increased, flexibility is lost, and if flexibility is to be imparted to the base film 1, the melting point tends to be lowered. As a material which can eliminate such a contradictory trade-off, the above-mentioned thermoplastic polyester elastomer having both a high melting point and flexibility is suitable. In particular, the material of the base film 1 is suitable in that both properties can be exhibited by a single layer even in a method of controlling the melting point and flexibility as the structure of the base film 1 without depending on the lamination of a layer having a high melting point and a layer having excellent flexibility.

(hard segment (A))

The hard segment (a) of the thermoplastic polyester elastomer is mainly composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol or an alicyclic diol, as described above. The aromatic polyester thus constituted is crystalline and has a high melting point. The hard domain formed of the crystalline polyester (hard segment) substantially functions as a crosslinking point by giving a node to a rubber-like soft segment described later. Accordingly, when the thermoplastic polyester elastomer is used as the material of the base film 1 of the dicing tape 10, the thermoplastic polyester elastomer is not easily melted during dicing, and is not easily converted into a filament-like shape because the crystallization rate is high even when the thermoplastic polyester elastomer is melted, and the generation of cutting chips in the form of filament-like pieces is suppressed.

The aromatic dicarboxylic acid constituting the polyester as the main component of the hard segment (a) is not particularly limited, and a general aromatic dicarboxylic acid can be used. Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, sodium 5-sulfoisophthalate, 2, 6-naphthalenedicarboxylic acid, and diphenyldicarboxylic acid. Among them, as the aromatic dicarboxylic acid, terephthalic acid, 2, 6-naphthalenedicarboxylic acid and the like are preferably used. Terephthalic acid is preferably used from the viewpoint of ultraviolet transmittance. The amount of the aromatic dicarboxylic acid used is preferably 75% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of the total acid components including other acid components. In addition, instead of the aromatic dicarboxylic acid, an ester-forming derivative of the aromatic carboxylic acid may be used and introduced into the polyester as an acid component. For example, alkyl esters of such acids are representative, with the use of methyl esters being particularly preferred. Specifically, methyl terephthalate is preferably used.

Examples of the other acid component include alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid and tetrahydrophthalic anhydride; aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, dimer acid, and hydrogenated dimer acid. The other acid component is used in an amount within a range not to significantly lower the crystal melting point of the thermoplastic polyester elastomer, and the amount thereof is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less of the total acid component. Further, ester-forming derivatives of these acids can also be used in the same manner as described above.

The aliphatic or alicyclic diol constituting the polyester as the main component of the hard segment (a) is not particularly limited, and a general aliphatic or alicyclic diol can be used. Examples of the aliphatic diol include alkylene glycols having 2 to 8 carbon atoms, and specific examples thereof include ethylene glycol, 1, 3-propanediol, 1, 4-butanediol, and 1, 6-hexanediol. As the alicyclic diol, 1, 4-cyclohexanediol, 1, 4-cyclohexanedimethanol, and the like can be used. Among them, 1, 4-butanediol or 1, 4-cyclohexanedimethanol is preferably used. From the viewpoint of general versatility and film-forming properties, 1, 4-butanediol, which is an aliphatic diol, is preferably used.

The component constituting the polyester as the main component of the hard segment (a) is preferably a polyester composed of butylene terephthalate units formed from terephthalic acid and 1, 4-butanediol (which may be referred to as polybutylene terephthalate (PBT)), or a polyester composed of butylene naphthalate units formed from 2, 6-naphthalenedicarboxylic acid and 1, 4-butanediol (which may be referred to as polybutylene naphthalate (PBN)), from the viewpoint of physical properties, moldability, and cost performance, and particularly preferably a polyester composed of butylene terephthalate units (PBT).

In addition, in the case where an aromatic polyester suitable as a polyester constituting the hard segment (a) in the thermoplastic polyester elastomer of the present invention is produced in advance and then copolymerized with the soft segment (B), the aromatic polyester can be obtained by a usual polyester production method. The number average molecular weight Mn of the aromatic polyester is preferably in the range of 10,000 to 40,000.

(Soft segment (B))

As described above, the soft segment (B) of the thermoplastic polyester elastomer is mainly composed of an aliphatic polyether. The aliphatic polyether has a low glass transition temperature (Tg) and is rubbery, and plays a role in imparting appropriate flexibility to the thermoplastic polyester elastomer by controlling the balance with the hard segment (a). Thus, when the thermoplastic polyester elastomer is used as the material of the base film 1 of the dicing tape 10, the flexural modulus (G') of the base film 1 at 23 ℃ can be controlled to a range that can improve the pick-up property of the thin-film semiconductor chip to the maximum, that is, a range of 10MPa to 135 MPa. If the bending elastic modulus (G') at 23 ℃ of the base film 1 is in the range of 10MPa to 135MPa, the dicing tape 10 is easily bent with the tip of the pin as a fulcrum when the dicing tape 10 is pushed up by the push-up pin at the time of picking up the semiconductor chip, and therefore, even if the push-up height of the push-up pin is small, that is, pushed up with a small force, peeling of the peripheral end portion of the semiconductor chip from the adhesive layer 2 is easily assisted.

As a result, even in the case of using a semiconductor wafer having a thin film of 100 μm or less, peeling of the thin film semiconductor chip from the adhesive layer 2 can be performed quickly, and the thin film semiconductor chip can be easily picked up from the adhesive layer 2 of the dicing tape 10 without damage with a smaller force than in the conventional art, and the pick-up success rate of the semiconductor chip can be further improved than in the conventional art.

The aliphatic polyether as the main component of the soft segment (B) is not particularly limited, and specific examples thereof include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (oxytetramethylene) glycol, a copolymer of ethylene oxide and propylene oxide, an ethylene oxide addition polymer of poly (propylene oxide) glycol, and a poly (alkylene oxide) glycol such as a copolymer of ethylene oxide and tetrahydrofuran.

Among the above aliphatic polyethers, poly (oxytetramethylene) glycol (PTMG), an ethylene oxide addition polymer of poly (propylene oxide) glycol (PPG-EO addition polymer), and a copolymer glycol of ethylene oxide and tetrahydrofuran (EO/THF copolymer glycol) are preferable, and poly (oxytetramethylene) glycol (PTMG) and an ethylene oxide addition polymer of poly (propylene oxide) glycol (PPG-EO addition polymer) are more preferable from the viewpoint of versatility and film-forming properties. The number average molecular weight Mn of these soft segments is preferably about 300 to 6,000 in a state after copolymerization. Specific examples thereof include PTMG850 (number average molecular weight Mn: molecular weight 850), PTMG1000 (number average molecular weight Mn: 1,000), PTMG1500 (number average molecular weight Mn: 1,500), PTMG2000 (number average molecular weight Mn: 2,000), PTMG3000 (number average molecular weight Mn: 3,000), PPG (addition mol 2) -EO (addition mol 9) addition polymer, PPG (addition mol 7) -EO (addition mol 14) addition polymer, PPG (addition mol 41) -EO (addition mol 36) addition polymer and the like.

The amount of the aliphatic polyether used is preferably 75% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of the total soft segment component including the soft segment components other than the aliphatic polyether.

Examples of the other soft segment component that can be used in combination with the aliphatic polyether include aliphatic polyesters such as polycaprolactone and polybutylene adipate, and aliphatic polycarbonates. The other soft segment component is used in an amount not to impair the flexibility of the thermoplastic polyester elastomer, and the amount thereof is preferably 25% by mass or less, more preferably 20% by mass or less, and particularly preferably 10% by mass or less of the total soft segment component.

A preferable embodiment of the thermoplastic polyester elastomer of the present embodiment is a block copolymer in which PBT or PBN is used for the hard segment (A) and PTMG or a PPG-EO addition polymer is used for the soft segment (B). Specifically, a block copolymer composed of PBT-PTMG-PBT, a block copolymer composed of PBT- (PPG-EO addition polymer) -PBT, a block copolymer composed of PBN-PTMG-PBN, and a block copolymer composed of PBN- (PPG-EO addition polymer) -PBN are preferable. From the viewpoint of ultraviolet light transmittance, a block copolymer composed of PBT-PTMG-PBT or a block copolymer composed of PBT- (PPG-EO addition polymer) -PBT is more preferable, and from the viewpoint of general versatility and film-forming properties, a block copolymer composed of PBT-PTMG-PBT is particularly preferable. These thermoplastic polyester elastomers may be used in combination of 2 or more as necessary within a range not impairing the effect of the present invention, but are preferably used alone from the viewpoint of film-forming properties.

The content (copolymerization amount) of the soft segment (B) in the thermoplastic polyester elastomer is preferably within a range of 51 mass% to 73 mass%, more preferably within a range of 55 mass% to 70 mass%, with respect to the total mass of the hard segment (a) and the soft segment (B) as constituent components. In the case where the base film 1 is a multilayer body composed of a plurality of layers, the content of the soft segment (B) means a value in the entire multilayer body calculated from the content of the soft segment (B) in each layer and the mass ratio of each layer in the entire layer. The mass ratio of the hard segment (a) to the soft segment (B) can be measured by an NMR measuring apparatus. When the soft segment (B) content is less than 51 mass%, the flexural modulus (G') of the base film 1 is too high, and the chip of the thin film wafer may be broken in the semiconductor manufacturing process in the semiconductor chip pickup process, and the pickup characteristics may be deteriorated. On the other hand, when the content of the soft segment (B) is more than 73 mass%, the film formation of the base film 1 itself may become difficult. Further, since the crystalline melting point of the base film 1 is low and the extensibility and the viscosity are also high, when a wafer is cut by a blade in a semiconductor manufacturing process, the base film 1 may melt and extend as a result of the base film 1 being cut into the dicing tape 10, and thereby, a filiform cutting chip may be generated, which may adhere to a semiconductor chip to lower the reliability of the semiconductor element or may cause a recognition error in a pickup process. When the content (copolymerization amount) of the soft segment (B) in the thermoplastic polyester elastomer is in the above range, the flexural modulus (G') of the base film 1 at 23 ℃ can be easily set to a suitable range of 10MPa to 135 MPa.

The thermoplastic polyester elastomer can be produced by a known method. For example, the following methods can be mentioned: a method in which a lower alcohol diester of dicarboxylic acid, an excessive amount of low molecular weight diol, and a soft segment component are subjected to transesterification reaction in the presence of a catalyst such as an organic acid salt or an organic metal compound, and the resulting reaction product is subjected to polycondensation in the presence of a catalyst such as an antimony compound, a titanium compound, or a germanium compound; a method in which a dicarboxylic acid, an excessive amount of a diol, and a soft segment component are subjected to an esterification reaction in the presence of a catalyst such as an organic acid salt or an organic metal compound, and the resulting reaction product is subjected to polycondensation in the presence of a catalyst such as an antimony compound, a titanium compound, or a germanium compound; a method in which an aliphatic polyether polyol and an appropriate aromatic polyester obtained from an aromatic dicarboxylic acid and a low-molecular-weight diol component are heated and mixed to depolymerize a part of the aromatic polyester and react with the aliphatic polyether polyol to polycondense the aromatic polyester; a method of preparing a hard segment in advance, adding a soft segment component thereto, and randomizing by a transesterification reaction; a method of linking the hard segment and the soft segment with a chain linking agent. In the case of a method of preparing a hard segment in advance, adding a soft segment component thereto, and randomizing the hard segment by a transesterification reaction, it is preferable to prepare a hard segment in advance, and add a soft segment component having a high molecular weight in advance thereto, and randomize the hard segment so that the transesterification reaction between the hard segment and the soft segment is not excessive, that is, excessive randomization is not induced. Specifically, the method described in patent No. 4244067 is preferable.

< other thermoplastic resin >

The resin constituting the base film 1 may contain a thermoplastic resin exemplified below as a component other than the thermoplastic polyester elastomer, within a range not impairing the effects of the present invention. Examples of such thermoplastic resins include polyolefin resins, polyamide resins, polycarbonate resins, thermoplastic resins such as homopolymer and copolymer resins containing a component derived from an aromatic vinyl monomer, thermoplastic elastomers other than the polyester-polyether block copolymer of the present embodiment, and poly (alkylene oxide) glycols that are not copolymerized with the polyester-polyether block copolymer. Examples of the polyolefin resin include polyethylene, polypropylene, a copolymer of ethylene and propylene, and a copolymer of these with an α -olefin having 4 to 10 carbon atoms. These polymers may be modified with an acid compound such as maleic anhydride. Further, the polyolefin-based resin contains a metal salt-based ionomer. The content of such another thermoplastic resin is preferably in a range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic polyester elastomer contained in the base film 1.

< Others >

The base film 1 may contain particles in the resin constituting the base film 1, from the viewpoint of imparting workability due to smoothness (blocking prevention), within a range not impairing the effects of the present invention. The particles are preferably contained in a single layer when the base film 1 is formed of a single layer, and are preferably contained in at least one outermost layer when the base film 1 is formed of a plurality of layers. The particles are not particularly limited, and inorganic particles and organic particles may be used alone or in combination. Examples of the inorganic particles include metal oxides such as silica, alumina, titania, and zirconia; barium sulfate, calcium carbonate, aluminum silicate, calcium phosphate, mica, kaolin, clay, zeolite, and the like. Examples of the organic particles include crosslinked particles of a polymethyloxysilane compound, crosslinked particles of a polyethylene compound, crosslinked particles of a polystyrene compound, crosslinked particles of an acrylic compound, crosslinked particles of a polyurethane compound, crosslinked particles of a polyester compound, crosslinked particles of a fluorine compound, and a mixture thereof. The average particle diameter of the particles is not particularly limited, but is preferably in the range of 0.5 μm to 15.0 μm. The content of the particles is preferably in a range of 1 to 20 parts by mass with respect to 100 parts by mass of the total amount of the thermoplastic polyester elastomer and the thermoplastic resin contained in the base film 1.

Further, the resin constituting the base film 1 may contain various additives such as a colorant, a flame retardant, a plasticizer, an antistatic agent, and an antioxidant, within a range not to impair the effects of the present invention. The content of these additives is not particularly limited, but should be kept within a range in which the base film 1 exerts the desired function and the flexibility is not lost.

< flexural modulus of elasticity of substrate film >

The base film 1 of the present embodiment has a flexural modulus (G') of 10MPa to 135MPa at 23 ℃ when the dynamic viscoelasticity is measured in the clamped-beam bending mode at a frequency of 1Hz and a temperature rise rate of 0.5 ℃/min. If the bending elastic modulus (G') at 23 ℃ of the base film 1 made of the resin containing the thermoplastic polyester elastomer is within the above range, both the high melting point of the base film 1 and the appropriate flexibility can be satisfied, and therefore, when the base film 1 is applied to a dicing tape, both suppression of the generation of chips during dicing and improvement of the pick-up property of the semiconductor chip can be achieved. From the viewpoint of further improving both properties, the flexural modulus (G') of the base film 1 at 23 ℃ is preferably in a range of 17MPa to 115 MPa.

The specific method of measuring the flexural modulus (G') of the substrate film 1 is as follows.

(1) Assay device

Dynamic viscoelasticity measuring apparatus "DMA 6100" (product name) manufactured by Hitachi High-Tech Science of K.K.)

(2) Assay sample

Sample preparation method: a plurality of samples having the following sample sizes were cut from a coil of the base film 1 after film formation, and the samples were stacked and closely pressed so that the total thickness thereof became 1.5mm by a hot press

Sample size: 10mm (width) × 50mm (length) × 1.5mm (thickness)

Here, each of the samples of the plurality of substrate films 1 prepared in advance is a material cut out from a position corresponding to the center in the width direction when the substrate film 1 is processed into a web of the dicing tape 10 so that the width direction of 10mm in the sample size coincides with the MD direction (flow direction) when the substrate film 1 is formed, and the length direction of 50mm in the sample size coincides with the TD direction (direction perpendicular to the MD direction) when the substrate film 1 is formed.

(3) Measurement conditions

Measurement mode: bending of two-end clamped beam

Measurement frequency: 1Hz

Measurement temperature range: 40 ℃ below zero to 40 DEG C

Temperature increase rate: 0.5 deg.C/min

Measurement of atmospheric gas: nitrogen gas

The value of the storage modulus at 23 ℃ in the dynamic viscoelastic spectrum obtained by the above measurement method was defined as the flexural elastic modulus (G') of the base film 1. When the flexural modulus (G') of the base film 1 at 23 ℃ is less than 10MPa, the base film 1 and the dicing tape 10 itself using the base film may be inferior in the handling property and workability. In addition, when a semiconductor device is manufactured using the dicing tape 10 using the base film 1, the following may occur in the semiconductor chip pickup step: the base film 1 of the dicing tape 10 excessively follows the bending motion of the semiconductor chip pushed up from the 2 nd surface side by the push-up pin, and it is difficult to provide a chance of peeling from the adhesive layer 2 at the peripheral end portion of the semiconductor chip, and the pickup property is deteriorated. On the other hand, when the bending elastic modulus (G') at 23 ℃ of the base film 1 is greater than 135MPa, the following may occur in the semiconductor chip pickup step when the dicing tape 10 using the base film 1 is used to manufacture a semiconductor device: even if the dicing tape 10 is pushed up by the push-up pins, the bending of the dicing tape 10 is small, and it is difficult to assist the peeling of the peripheral end portions of the semiconductor chip from the adhesive agent layer 2, and therefore the push-up height needs to be further increased, which results in an increased risk of cracking of the semiconductor chip.

< thickness of substrate film >

The thickness of the base film 1 of the present embodiment is not particularly limited, and for example, when applied to a dicing tape, it is preferably in the range of 70 μm to 155 μm, and more preferably in the range of 80 μm to 100 μm. When the base film 1 is a laminate structure, the thickness means the total thickness of the layers in total. When the thickness of the base film 1 is less than 70 μm, the base film 1 partially cut by a dicing blade may be broken in a subsequent spreading step when a semiconductor device is manufactured using the dicing tape 10 using the base film 1. On the other hand, when the thickness of the base film 1 is more than 155 μm, the web core may have a step mark causing poor quality when the dicing tape 10 is produced using the base film 1 and wound, and the permeability of active energy rays such as Ultraviolet (UV) rays required for curing the adhesive layer 2 may be deteriorated. In addition, warpage due to release of residual stress during film formation of the base film 1 may be increased.

When the base film 1 of the present embodiment is used as a base film of a dicing tape 10 described later, the base film 1 is preferably a laminate of a plurality of layers of different resins, and the thickness of the layer having the 1 st surface in contact with the adhesive layer 2 in the base film 1 is larger than the depth into which the base film 1 is cut by a dicing blade, and the content of the soft segment (B) of the thermoplastic polyester elastomer contained in this layer is preferably made smaller than the content of the soft segment (B) of the thermoplastic polyester elastomer contained in another layer. Thus, when the base film 1 is used as a base film of the dicing tape 10, the crystal melting point of the resin containing the thermoplastic polyester elastomer constituting the layer 1 having the 1 st surface in contact with the adhesive layer 2 in the base film 1 can be maintained higher, and therefore the generation of the filigree cutting chips in dicing of the base film 1 can be stably suppressed.

< crystal melting point of substrate film >

The crystal melting point of the base film 1 of the present embodiment means the crystal melting point of the same resin when the base film 1 is composed of only the same resin. In addition, when the base film 1 is a laminate composed of a plurality of layers of different resins, it means the crystal melting point of the resin constituting the layer having the 1 st surface in contact with the adhesive layer. Specifically, when the base film 1 of the laminate is used as a base film of a dicing tape 10 described later, it means a crystal melting point of a resin constituting a layer (i.e., a layer cut with a dicing blade) having the 1 st surface in contact with the adhesive agent layer 2 in the base film 1. The crystal melting point of the substrate film 1 is preferably 160 ℃ to 200 ℃, and more preferably 170 ℃ to 195 ℃. If the crystal melting point of the base film 1 is less than 160 ℃, when the semiconductor wafer is cut completely by the dicing saw, the base film 1 tends to generate filigree chips, and if the crystal melting point of the base film 1 is greater than 200 ℃, the flexural modulus (G') of the base film 1 tends to increase, so that when the dicing tape 10 is pushed up by the push-up pin in the pickup step, the flexibility of the dicing tape 10 decreases, and in the semiconductor chip pickup step, the push-up height needs to be increased, and as a result, the semiconductor chip is likely to break.

When the base film 1 is used as a base film of a dicing tape 10 described later by forming a laminate of a plurality of layers of different resins, it is preferable that the crystal melting point of the resin constituting the layer having the 1 st surface in contact with the adhesive layer 2 in the base film 1 is higher than the crystal melting point of the resin constituting the other layers. Thus, when the base film 1 is used as a base film of a dicing tape 10 described later, the generation of cutting chips in the form of silk chips during dicing of the base film 1 can be stably suppressed.

The crystalline melting point of the resin can be measured, for example, by using a differential scanning calorimeter "DSC-8321" (product name) manufactured by Kabushiki Kaisha corporation. Specifically, first, 10mg of a resin sample was filled in an aluminum pot, the temperature was raised to 290 ℃ at a temperature raising rate of 10 ℃/min under a nitrogen atmosphere, the temperature was maintained at the same temperature for 3 minutes, and then the aluminum pot was put into liquid nitrogen to be quenched. The aluminum pot after quenching was again placed in the differential scanning calorimeter "DSC-8321" and heated at a heating rate of 10 ℃/min, and the peak temperature of the endothermic peak occurring at this time was set as the crystal melting point of the resin.

< elongation of substrate film >

The substrate film 1 of the present embodiment preferably has an elongation in both the MD direction and the TD direction in the range of 300% to 700%, both measured by the method specified in JIS Z0237 (2009). Here, the elongation of 100% means a length elongated to 2 times the original length. As described above, the MD direction refers to the flow direction of the base film 1 during film formation, and the TD direction refers to the direction perpendicular to the MD direction. When the elongation of the base film 1 is less than 300%, the base film 1 tends to be hard, and therefore, the stretchability as a dicing tape and the semiconductor chip pickup property may be deteriorated. On the other hand, when the elongation of the base film 1 is more than 700%, the base film 1 is elongated and has a high viscosity, and therefore, the cutting chips may be easily generated in a filament shape during cutting.

< ultraviolet transmittance of substrate film >

When the active energy ray-curable adhesive composition described later is applied as the adhesive layer 2 to the substrate film 1 of the present embodiment, it is necessary to transmit active energy rays. In this case, specifically, for example, when Ultraviolet (UV) rays are used as the active energy rays, the parallel light transmittance of ultraviolet rays measured by a spectrophotometer of the base material film 1 is preferably 1% or more, and more preferably 5% or more at a wavelength of 365 nm. When the parallel light transmittance of ultraviolet rays of the substrate film 1 is less than 1%, the ultraviolet rays do not sufficiently reach the adhesive layer 2 containing the active energy ray-curable adhesive composition even if the substrate film 1 side of the dicing tape 10 is irradiated with ultraviolet rays, and therefore there is a concern that: the adhesive layer 2 is not sufficiently cured or shrunk, and the adhesive force to an adherend is not sufficiently reduced. As a result, in the step (pickup step) of peeling the semiconductor chip or the semiconductor chip with an adhesive layer from the adhesive layer 2, a pickup failure of the semiconductor chip or the semiconductor chip with an adhesive layer may occur. When the base film 1 has a parallel light transmittance of ultraviolet rays of 1% or more, the adhesive layer 2 including the active energy ray-curable adhesive composition can be sufficiently cured and shrunk, and thus the adhesive force to an adherend can be sufficiently reduced. As a result, the semiconductor chip or the semiconductor chip with the adhesive layer can be picked up satisfactorily.

< method for producing substrate film >

Examples of the method for forming the base film 1 of the present embodiment include conventional production methods such as a casting method, a T-die method, an inflation method, and a rolling method. Among them, the casting method is preferable in terms of not applying a shear stress and not causing orientation of polymer molecules when the base film 1 is formed, and being capable of uniformly extending without breaking when the base film 1 is stretched.

Specifically, for example, pellets of a resin which is a material of the base film 1 are dried as needed, and then a molten resin extruded at a temperature of 190 to 300 ℃ by an extruder such as a T-die is cooled by a single or a plurality of casting drums at a temperature of 30 to 70 ℃ while being sandwiched and pressurized or in one-side contact, thereby forming a film substantially without stretching, and a non-stretched film is manufactured. The substrate film 1 having a small thickness variation can be obtained by using an electrostatic sealing method, an air knife method, an attraction chamber method, or the like.

When the base film 1 is formed by lamination, a conventional film lamination method such as coextrusion or dry lamination can be used as a method for forming the base film 1.

Further, in order to stabilize winding during film formation of the base film 1 and prevent blocking after film formation, a method of winding the base film 1 by embossing the surface (2 nd surface) on the side opposite to the side on which the adhesive layer 2 is provided (1 st surface) or a method of winding the base film 1 by laminating it on a process release paper may be used. As the process release paper, a stretched polyester sheet generally called O-PET, a stretched polypropylene sheet generally called OPP, a process release paper made of paper, a process release paper obtained by coating paper with an olefin-based resin or a silicone-based resin, or the like can be suitably used. The process release paper may be peeled off when the dicing tape 10 is supplied to, for example, a dicing step after the base film 1 is formed into the shape of the dicing tape 10.

Cutting belt

The dicing tape 10 of the present invention includes an adhesive layer 2 for holding (temporarily fixing) a semiconductor wafer 30 on the 1 st surface of the base film 1. The dicing tape 10 may have a base sheet (release liner) having releasability on the surface of the adhesive layer 2. As the adhesive for forming the adhesive layer 2, a conventionally known adhesive can be used as the adhesive of the dicing tape 10. Such an adhesive is not particularly limited, and various adhesive compositions such as acrylic, silicone, polyester, polyvinyl acetate, polyurethane, and rubber can be used. Among them, acrylic pressure-sensitive adhesive compositions can be suitably used from the viewpoint of general-purpose and practical use.

< adhesive layer >

As the acrylic adhesive composition applied to the adhesive layer 2 of the present embodiment, any known or customary active energy ray non-curable acrylic adhesive composition and active energy ray curable acrylic adhesive composition can be used. Here, the "active energy ray-curable acrylic adhesive composition" means an adhesive composition in which the adhesive force is reduced by crosslinking and curing by irradiation with active energy rays such as ultraviolet rays, visible rays, infrared rays, electron rays, β rays, and γ rays, that is, an acrylic adhesive composition having a photosensitive carbon-carbon double bond. The expression "active energy ray-non-curable acrylic adhesive composition" means an adhesive composition whose adhesive force does not decrease even when irradiated with active energy rays, that is, an acrylic adhesive composition having no photosensitive carbon-carbon double bond. In the semiconductor chip pickup step, it is preferable to use an active energy ray-curable acrylic adhesive composition from the viewpoint of improving the pickup success rate (improving the pickup property) so that the semiconductor chip can be easily picked up without being damaged.

(active energy ray-non-curable acrylic adhesive composition)

The active energy ray-non-curable acrylic adhesive composition is typically a so-called normal acrylic adhesive composition including an acrylic adhesive polymer having a functional group and a crosslinking agent reactive with the functional group, but is not particularly limited thereto. The functional group as used herein means a heat-reactive functional group. Examples of such functional groups include active hydrogen groups such as hydroxyl groups, carboxyl groups, and amino groups; and a functional group such as a glycidyl group which thermally reacts with an active hydrogen 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.

[ acrylic pressure-sensitive adhesive Polymer having functional group ]

The main skeleton of the acrylic adhesive polymer having a functional group is composed of a copolymer of an alkyl (meth) acrylate-containing 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, and octadecyl (meth) acrylate; or a monomer having 5 or less carbon atoms, such as amyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ethyl (meth) acrylate, and methyl (meth) acrylate. 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, and 6-hydroxyhexyl (meth) acrylate; carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; amide monomers such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (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 2 or more of them may be used in combination. Examples of the glycidyl group-containing monomer include glycidyl (meth) acrylate and the like. The content of the thermally reactive functional group is not particularly limited, and is preferably in the range of 0.5 to 50 mass% based on the total amount of the comonomer components.

Specific examples of preferred copolymers obtained by copolymerizing the above monomers include, but are not particularly limited to, a copolymer of 2-ethylhexyl acrylate and acrylic acid, a copolymer of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate, a terpolymer of 2-ethylhexyl acrylate, methacrylic acid, and 2-hydroxyethyl acrylate, a copolymer of n-butyl acrylate and acrylic acid, a copolymer of n-butyl acrylate and 2-hydroxyethyl acrylate, and a terpolymer of n-butyl acrylate, methacrylic acid, and 2-hydroxyethyl acrylate.

The acrylic adhesive polymer having a functional group may contain other comonomer components as necessary for cohesive strength, heat resistance, and the like. Specific examples of such other comonomer components include cyano group-containing monomers such as (meth) acrylonitrile; ethylene, propylene, isopreneOlefin monomers such as butadiene and isobutylene; styrene monomers such as styrene, alpha-methylstyrene and vinyltoluene; vinyl ester monomers such as vinyl acetate and vinyl propionate; vinyl ether monomers such as methyl vinyl ether and ethyl vinyl ether; halogen atom-containing monomers such as vinyl chloride and vinylidene chloride; alkoxy group-containing monomers such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate; n-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole

And monomers having a nitrogen atom-containing ring such as oxazole, N-vinylmorpholine, N-vinylcaprolactam and N- (meth) acryloylmorpholine. These other comonomer components may be used alone, or 2 or more of them may be used in combination. The glass transition temperature (Tg) of the acrylic adhesive polymer having a functional group is preferably in the range of-70 ℃ to 15 ℃ inclusive, more preferably in the range of-60 ℃ to 10 ℃ inclusive.

[ crosslinking agent ]

In order to increase the molecular weight of the acrylic adhesive polymer having a functional group, the active energy ray-non-curable acrylic adhesive composition of the present embodiment 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, and the like, which are functional groups of the acrylic pressure-sensitive adhesive polymer, can be used. Specific examples thereof include a polyisocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, a melamine resin-based crosslinking agent, a urea resin-based crosslinking agent, an acid anhydride compound-based crosslinking agent, a polyamine-based crosslinking agent, and a carboxyl group-containing polymer-based crosslinking agent. Among them, a polyisocyanate-based crosslinking agent or an epoxy-based crosslinking agent is preferably used from the viewpoint of reactivity and versatility. These crosslinking agents may be used alone or in combination of 2 or more. The amount of the crosslinking agent is preferably in the range of 0.01 to 15 parts by mass per 100 parts by mass of the solid content of the acrylic adhesive polymer.

Examples of the polyisocyanate-based crosslinking agent include a polyisocyanate compound having an isocyanurate ring, an addition polyisocyanate compound obtained by reacting trimethylolpropane and hexamethylene diisocyanate, an addition polyisocyanate compound obtained by reacting trimethylolpropane and tolylene diisocyanate, an addition polyisocyanate compound obtained by reacting trimethylolpropane and xylylene diisocyanate, and an addition polyisocyanate compound obtained by reacting trimethylolpropane and 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-type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol triglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl erythritol, diglycerol polyglycidyl ether, 1,3 '-bis (N, N-diglycidylaminomethyl) cyclohexane, and N, N' -tetraglycidyl-m-xylylenediamine. 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 acrylic adhesive polymer having a functional group after the adhesive layer 2 is formed from the active energy ray non-curable resin composition are not particularly limited, and may be appropriately set, for example, in a temperature range of 23 ℃ to 80 ℃ and a time range of 24 hours to 168 hours.

[ others ]

The active energy ray non-curable acrylic pressure-sensitive adhesive composition of the present embodiment may further contain additives such as an adhesion promoter, a filler, an antioxidant, a colorant, a flame retardant, an antistatic agent, a surfactant, a silane coupling agent, and a leveling agent, as necessary, within a range not to impair the effects of the present invention.

(active energy ray-curable acrylic adhesive composition)

Typical examples of the active energy ray-curable acrylic adhesive composition include: an adhesive composition (A) comprising an acrylic adhesive polymer having a photosensitive carbon-carbon double bond and a functional group, a photopolymerization initiator, and a crosslinking agent reactive with the functional group; or an adhesive composition (B) comprising 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, but is not particularly limited thereto. Among them, the former type of adhesive composition (a) is preferable from the viewpoint of suppressing adhesive residue on a semiconductor wafer.

(adhesive composition (A))

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

The acrylic adhesive polymer having a carbon-carbon double bond and a functional group in the adhesive composition (a) is a compound having a carbon-carbon double bond in a molecular side chain. The method for producing the acrylic adhesive polymer having a carbon-carbon double bond is not particularly limited, and examples thereof include a method of obtaining a copolymer by copolymerizing a (meth) acrylate with a functional group-containing unsaturated compound, and 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. Here, as the copolymer before the addition reaction of the compound having a functional group and a carbon-carbon double bond, the same copolymer as the copolymer exemplified as the acrylic adhesive polymer having a functional group in the description of the active energy ray non-curable acrylic adhesive composition can be used.

The functional group referred to herein is a thermally reactive functional group capable of coexisting with a carbon-carbon double bond. Examples of such functional groups include active hydrogen groups such as hydroxyl groups, carboxyl groups, and amino groups; and a functional group such as a glycidyl group which thermally reacts with an active hydrogen 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.

Examples of the addition reaction include a method of reacting a hydroxyl group located in a side chain of the copolymer (acrylic adhesive polymer) with an isocyanate compound having a (meth) acryloyloxy group (for example, 2-methacryloyloxyethyl isocyanate, 4-methacryloyloxyn-butyl isocyanate, or the like), a method of reacting a carboxyl group located in a side chain of the copolymer with glycidyl (meth) acrylate, and a method of reacting a glycidyl group located in a side chain of the copolymer with (meth) acrylic acid. In carrying out these reactions, it is preferable that functional groups such as hydroxyl groups, carboxyl groups, and glycidyl groups remain in advance in order to crosslink the acrylic adhesive polymer with a crosslinking agent such as a polyisocyanate crosslinking agent or an epoxy crosslinking agent and to increase the molecular weight. For example, when an isocyanate compound having a (meth) acryloyloxy group is reacted with a copolymer having a hydroxyl group in a side chain, the blending ratio of the isocyanate compound having a (meth) acryloyloxy group and the copolymer may be adjusted so that the equivalent ratio [ (NCO)/(OH) ] of the isocyanate group (-NCO) 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 an active energy ray-reactive group (carbon-carbon double bond) such as a (meth) acryloyloxy group and a functional group can be obtained.

In the addition reaction, a polymerization inhibitor is preferably used in order to maintain the reactivity of the carbon-carbon double bond with active energy rays. The polymerization inhibitor is preferably a quinone-based polymerization inhibitor such as hydroquinone monomethyl ether. The amount of the polymerization inhibitor is not particularly limited, but is preferably in the range of usually 0.01 to 0.1 parts by mass based on the total amount of the base polymer and the radiation-reactive compound.

The acrylic adhesive polymer having a carbon-carbon double bond and a functional group (also referred to as an active energy ray-curable acrylic adhesive polymer in some cases) 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 acrylic adhesive polymer is less than 10 ten thousand, it is not preferable to obtain a high-viscosity active energy ray-curable resin composition solution of several thousand cP to several tens of thousands cP in view of coatability and the like. Further, there are cases where: the cohesive force of the adhesive agent layer 2 before the irradiation with the active energy ray is reduced, and when the semiconductor wafer is diced, the semiconductor chip is likely to be displaced, and image recognition is difficult. On the other hand, when the weight average molecular weight Mw is more than 200 ten thousand, there is no particular problem in the characteristics as an adhesive, but mass production of an acrylic adhesive polymer is difficult, and for example, the acrylic adhesive polymer is not preferable because it is gelled in some cases during synthesis. The weight average molecular weight Mw of the acrylic adhesive polymer is more preferably 30 to 150 ten thousand. Here, the weight average molecular weight Mw means a standard polystyrene conversion value measured by gel permeation chromatography.

The content of the carbon-carbon double bond in the acrylic adhesive polymer having a carbon-carbon double bond and a functional group is not limited to only an amount that can obtain a sufficient effect of reducing the adhesive force in the adhesive agent layer 2 after irradiation with the active energy ray, and varies depending on the use conditions such as the irradiation amount of the active energy ray, and the content of the carbon-carbon double bond is preferably in a range of 0.10meq/g or more and 2.00meq/g or less, and more preferably in a range of 0.50meq/g or more and 1.50meq/g or less. When the content of the carbon-carbon double bond is less than 0.10meq/g, the effect of reducing the adhesive force in the adhesive agent layer 2 after the irradiation of the active energy ray becomes small, and the picking-up failure of the semiconductor chip may increase. On the other hand, in the case where the content of the carbon-carbon double bond is more than 2.00meq/g, the following problems may occur: the fluidity of the adhesive in the adhesive layer 2 after irradiation with the active energy ray is insufficient, and the dicing tape 10 or the dicing die bonding film 20 does not sufficiently expand the gap between the semiconductor chips after expansion, and it is difficult to recognize the image of each semiconductor chip at the time of pickup. In addition, depending on the copolymerization composition of the acrylic adhesive polymer, polymerization may easily proceed during synthesis, or gelation may easily proceed during reaction, and synthesis may be difficult. When the carbon-carbon double bond content of the acrylic adhesive polymer was confirmed, the carbon-carbon double bond content was calculated by measuring the iodine value of the acrylic adhesive polymer.

Further, in the acrylic adhesive polymer having a carbon-carbon double bond and a functional group, it is preferable that a functional group such as a hydroxyl group, a carboxyl group, and a glycidyl group is previously left in order to crosslink the acrylic adhesive polymer with a crosslinking agent such as a polyisocyanate crosslinking agent or an epoxy crosslinking agent and further increase the molecular weight as described above. Among them, hydroxyl group and carboxyl group are more preferable. The hydroxyl value of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group is not particularly limited, but is preferably in the range of 5mgKOH/g to 100 mgKOH/g. The acid value of the acrylic pressure-sensitive adhesive polymer having a carbon-carbon double bond and a functional group is not particularly limited, but is preferably in the range of 0.5mgKOH/g to 30 mgKOH/g. If the hydroxyl value and the acid value of the acrylic adhesive polymer having a carbon-carbon double bond and a functional group are within the above ranges, the adhesive force of the adhesive layer 2 after irradiation with the active energy ray is stably reduced, and as a result, the pickup failure of the semiconductor chip can be further reduced, which is preferable.

[ photopolymerization initiator ]

The active energy ray-curable acrylic adhesive composition (a)) of the present embodiment contains a photopolymerization initiator that generates radicals by irradiation with active energy rays. The photopolymerization initiator generates radicals upon irradiation of the active energy ray-curable acrylic adhesive composition with an active energy ray, and initiates a crosslinking reaction of the carbon-carbon double bond of the active energy ray-curable acrylic adhesive polymer.

The photopolymerization initiator is not particularly limited, and conventionally known photopolymerization initiators can be used. Examples thereof include an alkylphenone-based radical polymerization initiator, an acylphosphine oxide-based radical polymerization initiator, and an oxime ester-based radical polymerization initiator. Examples of the alkylphenone-based radical polymerization initiator include a benzil methyl ketal-based radical polymerization initiator, an α -hydroxyalkylphenone-based radical polymerization initiator, and an aminoalkylphenone-based radical polymerization initiator. Specific examples of the benzil methylidene radical polymerization initiator include 2, 2' -dimethoxy-1, 2-diphenylethan-1-one (e.g., Omnirad651, manufactured by IGM Resins B.V. Co., Ltd.). Specific examples of the α -hydroxyalkylphenone-based radical polymerization initiator include 2-hydroxy-2-methyl-1-phenylpropan-1-one (trade name Omnirad1173, manufactured by IGM Resins B.V.), 1-hydroxycyclohexylphenyl ketone (trade name Omnirad184, manufactured by IGM Resins B.V.), 1- [4- (2-hydroxyethoxy) phenyl ] -2-hydroxy-2-methyl-1-propan-1-one (trade name Omnirad2959, manufactured by IGM Resins B.V.), 2-hydroxy-1- {4- [4- (2-hydroxy-2-methylpropiono-yl) benzyl ] phenyl } -2-methylpropan-1-one (trade name Omni 127, rad), IGM Resins b.v. inc.). Specific examples of the aminoalkylketone radical polymerization initiator include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one (trade name Omnirad907, manufactured by IGM Resins B.V.) and 2-benzylmethyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone (trade name Omnirad369, manufactured by IGM Resins B.V.). Specific examples of the acylphosphine oxide-based radical polymerization initiator include 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide (trade name OmniradTPO, manufactured by IGM Resins B.V.), bis (2,4, 6-trimethylbenzoyl) -phenylphosphine oxide (trade name Omnirad819, manufactured by IGM Resins B.V.), and oxime ester-based radical polymerization initiator (2E) -2- (benzoyloxyimino) -1- [4- (phenylthio) phenyl ] octane-1-one (trade name OmniradOXE-01, manufactured by IGM Resins B.V.). These photopolymerization initiators may be used alone, or 2 or more of them may be used in combination.

The amount of the photopolymerization initiator added is preferably in the range of 0.1 to 10.0 parts by mass per 100 parts by mass of the solid content of the active energy ray-curable acrylic adhesive polymer. When the amount of the photopolymerization initiator added is less than 0.1 part by mass, the photoreactivity to the active energy ray is insufficient, and therefore, the photo radical crosslinking reaction of the acrylic adhesive polymer is not sufficiently caused even if the active energy ray is irradiated, and as a result, the effect of reducing the adhesive force in the adhesive layer 2 after the active energy ray irradiation becomes small, and the picking-up failure of the semiconductor chip may increase. On the other hand, when the amount of the photopolymerization initiator added is more than 10.0 parts by mass, the effect is saturated, and is not preferable from the viewpoint of economy. Further, depending on the kind of the photopolymerization initiator, the adhesive layer 2 may be yellowed and have a poor appearance.

As a sensitizer for such a photopolymerization initiator, a compound such as dimethylaminoethyl methacrylate or 4-dimethylaminobenzoate may be added to the active energy ray-curable acrylic adhesive composition.

[ crosslinking agent ]

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

[ others ]

The active energy ray-curable acrylic pressure-sensitive adhesive composition (a)) of the present embodiment may further contain additives such as a polyfunctional acrylic monomer, a polyfunctional acrylic oligomer, an adhesion promoter, a filler, an antioxidant, a colorant, a flame retardant, an antistatic agent, a surfactant, a silane coupling agent, and a leveling agent, as necessary, within a range not impairing the effects of the present invention.

(adhesive composition (B))

[ acrylic pressure-sensitive adhesive Polymer having functional group ]

As the acrylic adhesive polymer having a functional group in the adhesive composition (B), the same polymers as exemplified as the acrylic adhesive polymer having a functional group in the description of the active energy ray non-curable acrylic adhesive composition 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 having at least 2 or more carbon-carbon double bonds in the molecule, which can be three-dimensionally networked by irradiation with active energy rays, is widely used. Specific examples of the active energy ray-curable compound include esters of (meth) acrylic acid and a polyol, 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, and dipentaerythritol hexa (meth) acrylate; isocyanurate or isocyanurate compound such as 2-propenyl-di-3-butenyl cyanurate, 2-hydroxyethyl bis (2-acryloyloxyethyl) isocyanurate, tris (2-methacryloyloxyethyl) isocyanurate, and the like. These active energy ray-curable compounds may be used alone, or 2 or more of them may be used in combination.

In addition, as the active energy ray-curable compound, in addition to the above-mentioned compounds, active energy ray-curable oligomers such as epoxy acrylate oligomers, urethane acrylate oligomers, and polyester acrylate oligomers can be used. The epoxy acrylate is synthesized by an addition reaction of an epoxy compound and (meth) acrylic acid. The urethane acrylate is synthesized, for example, by reacting an isocyanate group remaining at the end of an addition reaction product of a polyol and a polyisocyanate with a hydroxyl group-containing (meth) acrylate to introduce a (meth) acryloyl group into the molecular end. Polyester acrylates are synthesized by the reaction of polyester polyols with (meth) acrylic acid. The active energy ray-curable oligomer preferably has 3 or more carbon-carbon double bonds in the molecule from the viewpoint of the effect of reducing the adhesive force of the adhesive agent layer 2 after irradiation with an active energy ray. These active energy ray-curable oligomers may be used alone, or 2 or more kinds thereof may be used in combination.

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 more preferably in the range of 500 to 6,000 from the viewpoint of both the suppression of contamination of the semiconductor chip and the effect of reducing the adhesive force of the adhesive layer 2 after the irradiation with the active energy ray.

The hydroxyl value of the active energy ray-curable oligomer is not particularly limited, and is preferably 3mgKOH/g or less when the dicing tape 10 is used by being stuck immediately after polishing a semiconductor wafer. That is, the surface of the semiconductor wafer immediately after polishing is extremely active, and as the number of hydroxyl groups (hydroxyl groups of the active energy ray-curable oligomer) bonded to the active atoms of the active surface is smaller in the adhesive agent layer 2, the excessive increase in the adhesive force of the adhesive agent layer 2 after irradiation with the active energy ray can be suppressed, and thus the semiconductor chip can be easily peeled off from the adhesive agent layer 2. The hydroxyl value of the active energy ray-curable oligomer is more preferably 0 mgKOH/g.

The content of the active energy ray-curable compound is 5 to 500 parts by mass, preferably 50 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 the irradiation of the active energy ray, and the semiconductor chip can be easily picked up without being damaged.

[ photopolymerization initiator ]

The active energy ray-curable acrylic adhesive composition (B)) of the present embodiment contains a photopolymerization initiator that generates radicals by irradiation with active energy rays. As the photopolymerization initiator, the same photopolymerization initiators 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 the photopolymerization initiator added.

[ crosslinking agent ]

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

[ others ]

The active energy ray-curable acrylic pressure-sensitive adhesive composition (B) of the present embodiment may further contain additives such as an adhesion promoter, a filler, an antioxidant, a colorant, a flame retardant, an antistatic agent, a surfactant, a silane coupling agent, and a leveling agent, as necessary, within a range not to impair the effects of the present invention.

(thickness of adhesive layer)

The thickness of the adhesive agent layer 2 of the present embodiment is not particularly limited, but is preferably in the range of 3 μm to 50 μm, and more preferably in the range of 5 μm to 20 μm. In the case where the thickness of the adhesive layer 2 is less than 3 μm, the adhesive force of the dicing tape 10 may excessively decrease. In this case, for example, when dicing a semiconductor wafer, the dicing tape 10 cannot sufficiently hold the semiconductor chip, and the semiconductor chip may scatter. When used as a dicing die attach film, adhesion failure between the adhesive layer 2 and the die attach film 3 may occur. On the other hand, when the thickness of the adhesive agent layer 2 is larger than 50 μm, vibration during dicing is easily transmitted to the adhesive agent layer 2, and the amplitude becomes large, and the semiconductor wafer may be displaced from the reference position during dicing of the semiconductor wafer. In this case, defects (chipping) may occur in the semiconductor chips, and variations may occur in the size of each semiconductor chip.

Anchor coating

In the dicing tape 10 of the present embodiment, an anchor coat layer in accordance with the composition of the base film 1 may be provided between the base film 1 and the adhesive layer 2 depending on the manufacturing conditions of the dicing tape 10, the use conditions of the dicing tape 10 after the manufacturing, and the like. By providing the anchor coat layer, the adhesion force between the base material film 1 and the adhesive agent layer 2 is improved.

< Release liner >

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

< method for producing dicing tape >

Fig. 4 is a flowchart illustrating a method of manufacturing the dicing tape 10. First, a release liner is prepared (step S101: release liner preparation process). Next, a coating solution for the adhesive layer 2 (coating solution for forming the adhesive layer) is prepared as a material for forming the adhesive layer 2 (step S102: coating solution preparation step). The coating solution can be prepared by, for example, uniformly mixing and stirring an acrylic pressure-sensitive adhesive polymer, which is a constituent component of the adhesive layer 2, a crosslinking agent, and a diluting solvent. As the solvent, a general-purpose organic solvent such as toluene or ethyl acetate can be used.

Then, the coating solution for the adhesive layer 2 prepared in step S102 is applied to the release-treated surface of the release liner and dried to form the adhesive layer 2 having a predetermined thickness (step 103: adhesive layer forming step). The coating method is not particularly limited, and coating can be performed using, for example, a die coater, a comma coater (registered trademark), a gravure coater, a roll coater, a reverse coater, or the like. The drying conditions are not particularly limited, and for example, the drying temperature is preferably in the range of 80 ℃ to 150 ℃ and the drying time is preferably in the range of 0.5 minutes to 5 minutes. Subsequently, 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). Here, in the case of using a substrate film of a laminate composed of a plurality of layers of different resins as the substrate film 1, the side (1 st surface) of the layer composed of a resin having a crystalline melting point in the range of 160 ℃ to 200 ℃ is bonded to the adhesive layer 2. Finally, the formed adhesive layer 2 is aged at 40 ℃ for 72 hours, for example, to react the acrylic adhesive polymer with the crosslinking agent, thereby crosslinking and curing (step S106: heat curing step). Through the above steps, the dicing tape 10 including the adhesive layer 2 and the release liner in this order from the base film side on the base film 1 can be produced. In the present invention, the laminate having the release liner on the adhesive layer 2 is also referred to as a dicing tape 10.

As a method of forming the adhesive layer 3 on the substrate film 1, a method of applying a coating solution for the adhesive layer 2 on a release liner and drying the coating solution, and then laminating the substrate film 1 on the adhesive layer 2 is exemplified, but a method of directly applying a coating solution for the adhesive layer 2 on the substrate film 1 and drying the coating solution may be used. The former method is suitably used from the viewpoint of stable production.

The dicing tape 10 of the present embodiment may be in a form of being wound into a roll or in a form of being stacked with wide sheets. The dicing tape 10 in these forms may be cut into a sheet or tape form having a predetermined size.

Dicing die attach film

In the semiconductor manufacturing process, the dicing tape 10 of the present embodiment may be used as a dicing die bonding film 20 in which a die bonding film (adhesive layer) 3 is laminated on the adhesive layer 2 of the dicing tape 10 so as to be peelable from the adhesive layer. The die attach film (adhesive layer) 3 is used for bonding and connecting the diced semiconductor chips to the lead frame and the wiring board. In addition, when semiconductor chips are stacked, they also function as an adhesive layer between the semiconductor chips. Hereinafter, an example of the die attach film (adhesive layer) 3 when the dicing tape 10 of the present embodiment is used as the dicing die attach film 20 is shown, but the present invention is not particularly limited to this example.

< chip adhesive film (adhesive layer) >)

The die attach film (adhesive layer) 3 is a layer made of a thermosetting adhesive composition that is cured by heat. The adhesive composition is not particularly limited, and conventionally known materials can be used. As an example of a preferable embodiment of the adhesive composition, there can be mentioned, for example, a thermosetting resin composition containing a glycidyl group-containing (meth) acrylate copolymer as a thermoplastic resin, an epoxy resin as a thermosetting resin, and a curing agent for the epoxy resin as a curing agent. The die attach film (adhesive layer) 3 having such a composition preferably has the following characteristics: the adhesive composition is excellent in adhesion between the semiconductor chip and the supporting substrate and between the semiconductor chip and the semiconductor chip, and can impart electrode embeddability and/or lead embeddability, and the like, and can be adhered at a low temperature in a chip bonding step, and excellent curing can be obtained in a short time, and excellent reliability can be obtained after fixing with a sealant.

(glycidyl group-containing (meth) acrylate copolymer)

The glycidyl group-containing (meth) acrylate copolymer preferably contains at least an alkyl (meth) acrylate having an alkyl group with 1 to 8 carbon atoms and glycidyl (meth) acrylate as copolymer units. From the viewpoint of ensuring a suitable adhesive strength, the glycidyl (meth) acrylate-containing copolymer unit is preferably contained in a range of 0.5 to 6.0 mass% based on the total amount of the glycidyl (meth) acrylate-containing copolymer. From the viewpoint of adjusting the glass transition temperature (Tg), the glycidyl group-containing (meth) acrylate copolymer may optionally contain other monomers such as styrene and acrylonitrile as a copolymer unit.

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 handling (suppressing the stickiness) as a die attach film. In order to set the glycidyl group-containing (meth) acrylate copolymer to such a glass transition temperature, ethyl (meth) acrylate and/or butyl (meth) acrylate is suitably used 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 10 to 300 ten thousand, more preferably in the range of 50 to 200 ten thousand. When the weight average molecular weight Mw is within the above range, the adhesive strength, heat resistance and fluidity are easily suitable. Here, the weight average molecular weight Mw means a standard polystyrene conversion value measured by gel permeation chromatography.

The content ratio of the glycidyl group-containing (meth) acrylate copolymer in the die attach film (adhesive layer) 3 is preferably in the range of 50 to 95 mass%, and more preferably in the range of 50 to 90 mass%.

(epoxy resin)

The epoxy resin is not particularly limited, and examples thereof include 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 biphenol, diglycidyl etherate of naphthalene diol, diglycidyl etherate of phenol, diglycidyl etherate of alcohol, and bifunctional epoxy resins such as alkyl substitutes, halides, and hydrides thereof, and novolac type epoxy resins. In addition, other generally known epoxy resins such as polyfunctional epoxy resins and heterocyclic ring-containing epoxy resins can also be used. These may be used alone, or 2 or more of them may be used in combination.

From the viewpoint of properly exhibiting the function as a thermosetting adhesive in the die attach film (adhesive layer) 3, the content ratio of the epoxy resin in the die attach film (adhesive layer) 3 is preferably in the range of 5 mass% to 60 mass%, and more preferably in the range of 10 mass% to 50 mass%.

(curing agent for epoxy resin)

Examples of the curing agent for epoxy resins include phenolic resins obtained 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 phenol resin include novolak phenol resins, resol phenol resins, and polyoxyethylene such as poly-p-oxystyrene. Examples of the novolak type phenol resin include phenol novolak resin, phenol aralkyl resin, cresol novolak resin, tert-butylphenol novolak resin, and nonylphenol novolak resin. These phenol resins may be used alone, or 2 or more kinds may be used in combination. Of these phenol resins, phenol novolac resins and phenol aralkyl resins tend to improve the connection reliability of the die attach film (adhesive layer) 3, and are therefore suitably used.

From the viewpoint of sufficiently advancing the curing reaction between the epoxy resin and the phenol resin in the thermosetting resin composition, the phenol resin is preferably blended in the following amounts: the hydroxyl group in the phenolic resin is preferably in the range of 0.5 equivalent to 2.0 equivalents, more preferably 0.8 equivalent to 1.2 equivalents, relative to 1 equivalent of the epoxy group in the epoxy resin component.

(others)

If necessary, a curing accelerator such as a tertiary amine, an imidazole, or a quaternary ammonium salt may be added to the thermosetting resin composition. Specific examples of such a curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole and 1-cyanoethyl-2-phenylimidazole

Trimellitic acid ester, and the like, and they can be used alone, can also be used in combination of 2 or more.

Further, in the thermosetting resin composition, an inorganic filler may be added as necessary from the viewpoint of controlling the fluidity of the chip attachment film (adhesive layer) 3 and improving the elastic modulus. Specifically, there may be mentioned 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 them may be used in combination. The content ratio of the inorganic filler in the die attach film (adhesive layer) 3 is preferably in a range of 35 mass% to 60 mass%.

Further, a flame retardant, a silane coupling agent, an ion trapping agent, and the like may be added to the thermosetting resin composition as needed. Examples of the flame retardant include antimony trioxide, antimony pentoxide, and brominated epoxy resins. Examples of the silane coupling agent include β - (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ -glycidoxypropyltrimethoxysilane, and γ -glycidoxypropylmethyldiethoxysilane. Examples of the ion trapping agent include hydrotalcite, bismuth hydroxide, hydrous antimony oxide, zirconium phosphate having a specific structure, magnesium silicate, aluminum silicate, triazole-based compounds, tetrazole-based compounds, bipyridine-based compounds, and the like.

< thickness of die attach film (adhesive layer) >

The thickness of the die attach film (adhesive layer) 3 is not particularly limited, but is preferably in the range of 5 μm to 60 μm. If the thickness of the die attach film (adhesive layer) 3 is less than 5 μm, the adhesion between the semiconductor chip and the lead frame or wiring board may be insufficient. On the other hand, if the thickness of the die attach film (adhesive layer) 3 is larger than 60 μm, it is uneconomical and the response to the reduction in size and thickness of the semiconductor device is likely to be insufficient.

< method for producing die attach film >

The die attach film (adhesive layer) 3 is produced, for example, as follows. First, a release liner is prepared. As this release liner, the same release liner as the release liner disposed on the adhesive layer 2 of the dicing tape 10 can be used. Next, a coating solution for the die attach film (adhesive layer) 3 was prepared as a material for forming the die attach film (adhesive layer) 3. The coating solution can be prepared, for example, by uniformly mixing and dispersing a thermosetting resin composition containing a glycidyl group-containing (meth) acrylate copolymer, an epoxy resin, and a curing agent for the epoxy resin, which are components of the die attach film (adhesive layer) 3, and a diluting solvent. As the solvent, a general-purpose organic solvent such as methyl ethyl ketone or cyclohexanone can be used.

Next, the coating solution for the die attach 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 attach film (adhesive layer) 3 having a predetermined thickness. Then, the release-treated surface of the other release liner is bonded to the die attach film (adhesive layer) 3. The coating method is not particularly limited, and for example, a die coater, a comma coater (registered trademark), a gravure coater, a roll coater, a reverse coater, or the like can be used for coating. The drying conditions are preferably, for example, in the range of 70 ℃ to 160 ℃ in drying temperature and 1 minute to 5 minutes in drying time. In the present invention, a laminate having a release liner on both surfaces or one surface of the die attach film (adhesive layer) 3 is also referred to as a die attach film (adhesive layer) 3.

< method for producing die attach film for dicing >

The method for producing the dicing die bonding film 20 is not particularly limited, and can be produced by a conventionally known method. For example, the dicing die attach film 20 may be prepared by preparing the dicing tape 10 and the die attach film 20 separately, peeling the adhesive layer 2 of the dicing tape 10 and the release liner of the die attach film (adhesive layer) 3 separately, and laminating the adhesive layer 2 of the dicing tape 10 and the die attach film (adhesive layer) 3 by a laminating roller such as a hot roll laminator. The bonding temperature is preferably, for example, 10 ℃ to 100 ℃ and the bonding pressure (line pressure) is preferably, for example, 0.1kgf/cm to 100 kgf/cm. In the present invention, the dicing die attach film 20 is sometimes referred to as a dicing die attach film 20 as a laminate having a release liner on the adhesive layer 2 and the die attach film (adhesive layer) 3. In the dicing die attach film 20, the release liner provided on the adhesive layer 2 and the die attach film (adhesive layer) 3 may be peeled off when the dicing die attach film 20 is applied to a workpiece.

The dicing die bonding film 20 may be in a roll form or a form in which wide sheets are stacked. The dicing tape 10 in these forms may be cut into a sheet or tape form having a predetermined size.

For example, as disclosed in japanese patent application laid-open No. 2011-159929, the semiconductor device can be manufactured as a film roll in which an adhesive layer (die attach film) and an adhesive film (dicing tape) are formed in an island shape on a release substrate (release liner) and are pre-cut into a wafer shape constituting a semiconductor element. In this case, the dicing tape 10 is formed in a circular shape having a diameter larger than the die attach film (adhesive layer) 3, and the die attach film (adhesive layer) 3 is formed in a circular shape having a diameter larger than the semiconductor wafer 30.

Method for manufacturing semiconductor chip

Fig. 5 is a flowchart illustrating a method for manufacturing a semiconductor chip using the dicing tape 10 or the dicing die attach film 20 according to the present embodiment. Fig. 6 is a schematic view showing a state in which a ring frame (wafer ring) is attached to an outer edge portion of a dicing tape (or dicing die attach film) and a semiconductor wafer is attached to a central portion thereof. Further, fig. 7(a) to (f) are diagrams showing examples of manufacturing a semiconductor chip using a dicing tape in which the adhesive layer 2 is laminated on the base film 1 according to the present embodiment. Further, fig. 8(a) to (f) are diagrams showing examples of manufacturing semiconductor chips using the dicing die attach film 20 in which the die attach film (adhesive layer) 3 is laminated on the adhesive layer 2 of the dicing tape 10 according to the present embodiment.

Method for manufacturing semiconductor chip using dicing tape 10

First, as shown in fig. 7 a, a semiconductor wafer 30 having a plurality of integrated circuits (not shown) mounted on the semiconductor wafer 30 mainly composed of silicon, for example, is prepared (step S201: preparation step).

Next, the surface of the semiconductor wafer 30 opposite to the surface on which the integrated circuits are mounted is polished to a predetermined thickness of the semiconductor wafer 30 (step S202: polishing step). At this time, although not shown, a protective tape (back-grinding tape) is attached to the surface of the semiconductor wafer 30 on which the integrated circuits are mounted. The protective tape is peeled off before the cutting (dicing) step of the semiconductor wafer 30.

The thickness of the semiconductor wafer 30 is preferably adjusted to 100 μm or less, and more preferably to 20 μm or more and 50 μm or less. Although semiconductor chips are desired to be thin, if the thickness is reduced, the semiconductor chips become brittle and easily break, and the yield is deteriorated. The dicing tape of the present invention can pick up a semiconductor chip having a small thickness without damage at a push-up speed within an allowable range in practical use and with a smaller push-up height.

Next, as shown in fig. 6 and 7(a), after the release liner is peeled off from the adhesive layer 2 of the dicing tape 10 cut into a circular shape, the ring frame (wafer ring) 40 is attached to the outer edge portion of the adhesive layer 2 of the dicing tape 10, and the semiconductor wafer 30 is attached to the central portion of the adhesive layer 2 of the dicing tape 10 (step S203: attaching step). In the case where the dicing tape 10 is attached immediately after the semiconductor wafer 30 is polished in step 202, the dicing tape 10 is attached to the semiconductor wafer 30 in a state where active atoms are present on the surface of the semiconductor wafer 30.

In the sticking step, the dicing tape 10 is generally stuck to the semiconductor wafer 30 using a pressure roller or the like that presses the adhesive tape. The sticking temperature is not particularly limited, but is preferably in the range of, for example, 20 ℃ to 80 ℃. The pressure at the time of application is not particularly limited, but is preferably in the range of, for example, 0.1MPa to 0.3 MPa. The dicing tape 10 may be attached to the semiconductor wafer 30 by laminating the semiconductor wafer 30 and the dicing tape 10 in a pressurizable container (e.g., autoclave) and pressurizing the inside of the container. Further, the dicing tape 10 may be attached to the semiconductor wafer 30 in a decompression chamber (vacuum chamber).

Next, as shown in fig. 7 b, in a state where the dicing tape 10 and the semiconductor wafer 30 are bonded to each other, the semiconductor wafer 30 is cut into individual pieces by a dicing blade from the side on which the integrated circuits are mounted to a predetermined size along the line X to cut (dicing) by a dicing saw or the like according to a conventional method to form semiconductor chips 30a (step S204: cutting (dicing) step). As shown in fig. 7(c), in this example, so-called full dicing in which the semiconductor wafer 30 is completely cut is performed. In the cutting step of cutting the semiconductor wafer 30, it is desirable to cut only the semiconductor wafer 30 in order to obtain the semiconductor chips 30a, but actually, in view of the operation accuracy of the apparatus, the dicing tape 10 used, and the thickness accuracy of the semiconductor wafer 30, it is preferable to cut the adhesive layer 2 and a part of the base film 1 in order to obtain the semiconductor chips 30a accurately, as shown in fig. 7 (c).

As described above, even if the base material film 1 of the present embodiment is partially cut, the base material film 1 is less likely to generate the filiform cutting chips at the time of cutting. Therefore, the pickup failure of the semiconductor chip 30a can be suppressed. The depth of cut into the base film 1 by the dicing blade is not particularly limited, and from the viewpoint of suppressing the balance between the generation of cutting chips and the strength of the base film 1 partially cut (the strength at which the base film 1 does not break in the spreading step described later), 1/2 is preferably set to the thickness of the base film 1, and 1/4 is more preferably set to the thickness of the base film 1.

Here, in the cutting step, generally, the semiconductor wafer 30 to which the dicing tape 10 is attached is cut into a predetermined size by using, for example, a rotating blade while supplying washing water to the semiconductor wafer 30 in order to remove frictional heat and prevent adhesion of cutting chips.

Subsequently, the dicing tape 10 is irradiated with active energy rays from the base film 1 side, thereby curing and shrinking the adhesive layer 2 and reducing the adhesive force of the adhesive layer 2 (step S205: active energy ray irradiation step). Here, the active energy ray used for the post-irradiation includes ultraviolet rays, visible rays, infrared rays, electron rays, β rays, γ rays, and the like. These active energy raysAmong them, ultraviolet rays (UV) and Electron Beams (EB) are preferably used, and ultraviolet rays (UV) are particularly preferably used. The light source for irradiating the Ultraviolet (UV) 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 halide lamp, a xenon lamp, or the like can be used. Further, an ArF excimer laser, a KrF excimer laser, an excimer lamp, synchrotron radiation, or the like may be used. The amount of the Ultraviolet (UV) light is not particularly limited, but is preferably 100mJ/cm, for example²Above 2000J/cm²The range below, more preferably 300mJ/cm²Above 1000J/cm²The following ranges.

The active energy ray irradiation step may be performed only when the adhesive agent layer 2 of the dicing tape 10 is made of an active energy ray-curable adhesive composition, and the active energy ray irradiation step is not necessary when the adhesive agent layer 2 of the dicing tape 10 is made of an active energy ray-non-curable adhesive composition.

Next, in order to easily pick up each semiconductor chip 30a formed by dicing, as shown in fig. 7(d), after the cutting step, the dicing tape 10 is stretched (expanded) (step S206: expansion step). Specifically, the dicing tape 10 holding the plurality of cut semiconductor chips 30a is expanded in such a manner that the hollow cylindrical push-up member is lifted from the lower surface side of the dicing tape 10, and the dicing tape 10 is radially stretched in the two-dimensional directions including the radial direction and the circumferential direction of the ring frame (wafer ring) 40. The expanding step can expand the interval between the semiconductor chips 30a, improve the visibility of the semiconductor chips 30a by a CCD camera or the like, and prevent the semiconductor chips 30a from being re-bonded to each other due to the adjacent semiconductor chips 30a coming into contact with each other at the time of picking up. As a result, the semiconductor chip 30a is improved in the pick-up property.

Next, so-called picking, i.e., peeling off each of the semiconductor chips 30a singulated by cutting the semiconductor wafer 30 from the dicing tape 10, is performed (step S207: peeling (picking) step).

Examples of the pickup method include the following methods: as shown in fig. 7(e), the 2 nd surface of the base film 1 of the dicing tape 10 is pushed up by the push-up pins (needles) 60 with respect to the semiconductor chip 30a, and as shown in fig. 7(f), the semiconductor chip 30a after the push-up is sucked by the suction collet 50 of the pickup device (not shown) and peeled off from the adhesive layer 2 of the dicing tape 10. Thereby, the semiconductor chip 30a is obtained.

The pickup conditions are not particularly limited as long as the range is practically allowable, and generally, the speed of pushing up the push-up pins (needles) 60 is often set in a range of 1 mm/sec to 100 mm/sec, but when the thickness of the semiconductor chip 30a (the thickness of the semiconductor wafer) is as thin as 100 μm, it is preferably set in a range of 1 mm/sec to 20 mm/sec from the viewpoint of suppressing damage to the semiconductor thin film chip. From the viewpoint of productivity, it is more preferably set in the range of 5 mm/sec to 20 mm/sec.

The push-up height of the push-up pin that can pick up the semiconductor chip 30a without damage may be set to a range of preferably 100 μm to 600 μm from the same viewpoint as described above, and more preferably 100 μm to 450 μm from the viewpoint of reducing stress on the semiconductor thin film chip. From the viewpoint of productivity, it is particularly preferable to set the thickness in the range of 100 μm to 350 μm. It can be said that the cut tape having such a smaller push-up height can be made excellent in the pick-up property.

As described above, in the dicing tape 10 of the present embodiment, the dicing tape 10 is easily bent when the dicing tape 10 is pushed up by the push-up pin in the peeling (pickup) step of the semiconductor chip 30 a. Therefore, even if the push-up height of the push-up pin is small, that is, the push-up is performed with a small force, the peeling of the peripheral end portion of the semiconductor chip 30a from the adhesive layer 2 is easily assisted. As a result, even when an extremely thin semiconductor wafer 30 having a low strength of 100 μm or less is used, the extremely thin semiconductor chips 30a can be quickly peeled off from the adhesive layer, and the extremely thin semiconductor chips 30a can be easily picked up from the adhesive layer 2 of the dicing tape 10 without being damaged with a smaller force than in the conventional case. This can improve the success rate of picking up the semiconductor chip 30a more than ever.

The manufacturing method described in fig. 7(a) to (f) is an example of the manufacturing method of the semiconductor chip 30a using the dicing tape 10, and the method of using the dicing tape 10 is not limited to the above method. That is, the dicing tape 10 of the present embodiment is not limited to the above-described method as long as it is attached to the semiconductor wafer 30 at the time of dicing.

For example, when the dicing tape 10 of the present embodiment is used, the dicing method of the semiconductor wafer may be a method of not generating chips other than the above-described blade dicing method, such as the following method: the semiconductor wafer is cut by forming a scribe line while selectively forming a modified layer by irradiating the inside of the semiconductor wafer with laser light, and vertically growing a crack by a low-temperature expansion process at-15 ℃, for example, using the modified layer as a starting point.

Method for manufacturing semiconductor chip using die attach film for dicing 20

A method for manufacturing the semiconductor chip 30a when the dicing tape 10 of the present embodiment is used as the dicing die bonding film 20 will also be described. The method for manufacturing semiconductor chips using the dicing tape 10 is basically the same as the method for manufacturing semiconductor chips using the dicing tape 10 described above, except that the die attach film (adhesive layer) 3 is present between the adhesive layer 2 of the dicing tape 10 and the semiconductor wafer 30. When the dicing die bonding film 20 is used, the semiconductor chip 30a is picked up in a state in which the die bonding film (adhesive layer) 3 is bonded to the surface opposite to the surface on which the integrated circuit is mounted, that is, in a form of the semiconductor chip with the adhesive layer.

First, a semiconductor wafer 30 prepared in the same manner as the above-described method for manufacturing semiconductor chips using the dicing tape 10 is polished to a predetermined thickness (step S201: preparation step, step S202: polishing step). Next, after the release liner is peeled from the adhesive layer 2 and the die attach film (adhesive layer) 3 of the dicing die attach film 20 cut into a circular shape, as shown in fig. 6 and 8 a, the ring frame (wafer ring) 40 is attached to the outer edge portion of the adhesive layer 2 of the dicing tape 10, and the semiconductor wafer 30 is attached to the die attach film (adhesive layer) 3 laminated on the upper center portion of the adhesive layer 2 of the dicing tape 10 (step S203: attaching step).

Next, as shown in fig. 8 b, in a state where the dicing die bonding film 20 is bonded to the semiconductor wafer 30, the semiconductor wafer 30 is cut into individual pieces by a dicing saw or the like along the line X to cut (cut) a predetermined size from the side on which the integrated circuit is mounted, along the line X to cut, and a semiconductor chip 30a is formed (step S204: cutting (dicing) step). As shown in fig. 8(c), in this example, so-called full dicing is performed to completely cut the semiconductor wafer 30. In the cutting step of cutting the semiconductor wafer 30, it is desirable to cut only the semiconductor wafer 30 in order to obtain the semiconductor chips 30a, but actually, in view of the operation accuracy of the apparatus, the thickness accuracy of the dicing tape 10 and the semiconductor wafer 30 to be used, it is preferable to cut a part of the die attach film (adhesive layer) 3, the adhesive layer 2 and the base film 1 in order to obtain the semiconductor chips 30a accurately, as shown in fig. 8 (c).

The depth of cut into the base film 1 by the blade is not particularly limited, and from the viewpoint of suppressing the balance between the generation of cutting chips and the strength of the base film 1 partially cut (the strength at which the base film 1 does not break in the spreading step described later), 1/2 is preferably set to the thickness of the base film 1, and 1/4 is more preferably set to the thickness of the base film 1.

Next, as in the above-described method for manufacturing semiconductor chips using the dicing tape 10, step S205 is performed as necessary: the active energy ray irradiation step, then, via step S206: the expanding step (see fig. 8 d), then, via step S207: the peeling (picking-up) step (see fig. 8 e and 8 f) enables easy picking up of the extremely thin semiconductor chip 30a with the die attach film (adhesive layer) 3 from the adhesive layer 2 of the dicing die attach film 20 even when the extremely thin semiconductor wafer 30 having a low strength of 100 μm or less is used.

The manufacturing method described in fig. 8(a) to (f) is an example of the manufacturing method of the semiconductor chip 30a using the dicing die bonding film 20, and the method of using the dicing tape 10 as the form of the dicing die bonding film 20 is not limited to the above-described method. That is, the dicing die bonding film 20 of the present embodiment is not limited to the above-described method, and may be used as long as it is attached to the semiconductor wafer 30 at the time of dicing.

For example, when the dicing tape 10 of the present embodiment is used as the dicing die bonding film 20, the dicing method of the semiconductor wafer may be a method of not generating chips other than the above-described dicing method using a blade, such as the following method: the semiconductor wafer is cut together with the die attach film by forming scribe lines while selectively forming a modified layer by irradiating the inside of the semiconductor wafer with laser light, and vertically growing cracks by a low temperature expansion process at-15 ℃, for example, using the modified layer as a starting point.

[ examples ]

Next, the present invention will be further specifically described using examples and comparative examples. The present invention is not limited to the following examples.

1. Production of substrate film 1

As materials for producing the base film 1, the following resins a to I were prepared. The resins a to G are thermoplastic polyester elastomers produced from dimethyl terephthalate and 1, 4-butanediol as hard segment (PBT) components, and poly (oxytetramethylene) glycol (PTMG1000) having a number average molecular weight of 1,000, or poly (oxytetramethylene) glycol (PTMG1500) having a number average molecular weight of 1,500, or poly (oxytetramethylene) glycol (PTMG2000) having a number average molecular weight of 2,000 as soft segment components.

(resin)

Resin A: a thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG2000) of 27 mass%/73 mass%, a crystal melting point of 160 DEG C

Resin B: a thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG2000) of 33 mass%/67 mass%, and a crystal melting point of 180 DEG C

Resin C: a thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG1000) of 39 mass%/61 mass%, a crystal melting point of 172 DEG C

Resin D: thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG1500) of 45 mass%/55 mass%, crystal melting point 186 DEG C

Resin E: a thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG1500) of 51 mass%/49 mass%, and a crystal melting point of 192 DEG C

Resin F: thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG1500) of 54 mass%/46 mass%, crystal melting point 198 DEG C

Resin G: a thermoplastic polyester elastomer having a segment ratio of polybutylene terephthalate (PBT)/poly (oxytetramethylene) glycol (PTMG1000) of 64 mass%/36 mass%, a crystal melting point of 203 DEG C

Resin H: random copolymer polypropylene (PP) with a crystal melting point of 138 DEG C

Resin I: ethylene-vinyl acetate copolymer (EVA) having a vinyl acetate content of 20% by mass and a crystal melting point of 82 DEG C

Resin J: low Density Polyethylene (LDPE) having a crystalline melting point of 116 deg.C

[ Crystal melting Point of resin ]

The crystal melting point of the resin was measured as follows using a differential scanning calorimeter "DSC-8321" (product name) manufactured by Kyowa Kagaku K.K.K.K.. First, 10mg of each resin sample was charged into an aluminum pot, the temperature was raised to 290 ℃ at a temperature raising rate of 10 ℃/min under a nitrogen atmosphere, the temperature was maintained at the same temperature for 3 minutes, and then the aluminum pot was put into liquid nitrogen to be quenched. Subsequently, the aluminum pot after quenching was again set in the differential scanning calorimeter "DSC-8321" and the peak temperature of the endothermic peak occurring when the temperature was raised at a temperature raising rate of 10 ℃/min was set as the crystal melting point of the corresponding resin.

(substrate film 1(a))

A 100 μm thick base film 1(a) composed of a single layer was formed using the resin B (PBT/PTMG 2000: 33 mass%/67 mass%) by a T-die extrusion molding machine.

(substrate film 1(b))

A 100 μm thick base film 1(b) composed of a single layer was formed using the resin C (PBT/PTMG 1000: 39 mass%/61 mass%) by a T-die extrusion molding machine.

(base film 1(c))

A 100 μm thick base film 1(c) composed of a single layer was formed using the resin D (PBT/PTMG1500 ═ 45 mass%/55 mass%) by a T-die extrusion molding machine.

(substrate film 1(d))

A base film 1(d) having a thickness of 100 μm and composed of 3 layers of the same resin was formed using the resin a (PBT/PTMG 2000: 27 mass%/73 mass%) by a 1-type 3-layer T-die coextrusion molding machine. The thickness of each layer was 20 μm/60 μm/20 μm, where 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer.

(substrate film 1(e))

A base film 1(e) having a thickness of 100 μm and composed of 2 resin 3 layers was formed by a 2-layer 3-die co-extrusion molding machine using the resin a (PBT/PTMG 2000: 27 mass%/73 mass%) as the resin of the 2 nd layer and the resin B (PBT/PTMG 2000: 33 mass%/67 mass%) as the resins of the 1 st and 3 rd layers. The thickness of each layer was 25 μm/50 μm/25 μm, where 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer. The mass ratio of the segment of PBT and PTMG as the entire layer was 30 mass%/70 mass%.

(substrate film 1(f))

A base film 1(f) having a thickness of 100 μm and composed of 2 resin 3 layers was formed by a 2-layer 3-die co-extrusion molding machine using the resin C (PBT/PTMG 1000: 39 mass%/61 mass%) as the resin of the 2 nd layer and the resin D (PBT/PTMG 1500: 45 mass%/55 mass%) as the resins of the 1 st and 3 rd layers. The thickness of each layer was 30 μm/40 μm/30 μm, where 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer. The mass ratio of the segment of PBT and PTMG as the entire layer was 43 mass%/57 mass%.

(substrate film 1(g))

A base film 1(g) having a thickness of 100 μm, which is composed of 2 resin layers, was formed by a 2-layer T-die coextrusion molding machine using the resin E (PBT/PTMG1500 ═ 51 mass%/49 mass%) as the resin of the 1 st layer and the resin D (PBT/PTMG1500 ═ 45 mass%/55 mass%) as the resin of the 2 nd layer. The thickness of each layer was 30 μm/70 μm for the 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer. The mass ratio of the segment of PBT and PTMG as the entire layer was 47 mass%/53 mass%.

(substrate film 1(h))

A base film 1(h) having a thickness of 100 μm, which is composed of 2 resin layers, was formed by a 2-layer T-die coextrusion molding machine using the resin E (PBT/PTMG1500 ═ 51 mass%/49 mass%) as the resin of the 1 st layer and the resin D (PBT/PTMG1500 ═ 45 mass%/55 mass%) as the resin of the 2 nd layer. The thickness of each layer was 60 μm/40 μm for the 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer. The mass ratio of the segment of PBT and PTMG as the entire layer was 49 mass%/51 mass%.

(substrate film 1(i))

A base film 1(i) having a thickness of 155 μm and composed of 3 layers of the same resin was formed using the resin a (PBT/PTMG 2000: 27 mass%/73 mass%) by a 1-type 3-layer T-die coextrusion molding machine. The thickness of each layer was 20 μm/115 μm/20 μm, where 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer.

(base film 1(j))

A substrate film 1(j) having a thickness of 70 μm, which is composed of 2 resin 3 layers, was formed by a 2-layer 3-die co-extrusion molding machine using the resin C (PBT/PTMG 1000: 39 mass%/61 mass%) as the resin of the 2 nd layer and the resin D (PBT/PTMG 1500: 45 mass%/55 mass%) as the resins of the 1 st and 3 rd layers. The thickness of each layer was 20 μm/30 μm/20 μm, where 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer. The mass ratio of the segment of PBT and PTMG as the entire layer was 42 mass%/58 mass%.

(substrate film 1(k))

Using the resin i (eva) as the resin of the 2 nd layer and the resin h (pp) as the resins of the 1 st and 3 rd layers, a 80 μm thick base film 1(k) composed of 3 layers of 2 kinds of resins was formed by a 2-layer 3-layer T-die coextrusion molding machine. The thickness of each layer was set to 8 μm/64 μm/8 μm for the 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer. The mass ratio of PP/EVA as the whole layer was 20 mass%/80 mass%.

(substrate film 1(l))

A 90 μm thick base film 1(l) composed of 2 resin 3 layers was formed using the resin h (pp) as the resin of the 2 nd layer and the resin j (pe) as the resins of the 1 st and 3 rd layers by a 2-layer 3-layer T-die coextrusion molding machine. The thickness of each layer was 10 μm/70 μm/10 μm, i.e., 1 st layer (one surface side in contact with the adhesive agent layer)/2 nd layer/3 rd layer. The mass ratio of PE/PP as the whole layer was 22 mass%/78 mass%.

(substrate film 1(m))

A 100 μm thick base film 1(m) composed of a single layer was formed using the resin F (PBT/PTMG 1500: 54 mass%/46 mass%) by a T-die extrusion molding machine.

(base film 1(n))

A 100 μm thick base film 1(n) composed of a single layer was formed using the resin G (PBT/PTMG 1000: 64 mass%/36 mass%) by a T-die extrusion molding machine.

[ flexural modulus of elasticity (G') ] of base film

The flexural modulus (G') at 23 ℃ was measured for the substrate films 1(a) to (n) using a dynamic viscoelasticity measuring apparatus "DMA 6100" (product name) manufactured by Hitachi High-Tech Science of Japan, Ltd. First, as a sample for measurement, a laminate was prepared by cutting out a plurality of samples having the following sample sizes from a roll of the base film 1, stacking them, and pressing and bonding them together using a hot press so that the total thickness became 1.5 mm. The sample size was set to 10mm (width) × 50mm (length) × 1.5mm (thickness). Here, as the samples of the plurality of substrate films 1 prepared in advance, materials obtained by cutting out the substrate film 1 from a position corresponding to the center in the width direction when the substrate film 1 is processed into a web of the dicing tape 10 such that the width direction of 10mm in the sample size coincides with the MD direction (flow direction) when the substrate film 1 is formed, and the length direction of 50mm in the sample size coincides with the TD direction (direction perpendicular to the MD direction) when the substrate film 1 is formed. These measurement samples were set in a dynamic viscoelasticity measurement apparatus, and the dynamic viscoelasticity was measured under the conditions of a frequency of 1Hz, a temperature rise rate of 0.5 ℃/min, a measurement temperature range of-40 ℃ to 40 ℃ and a nitrogen atmosphere by using a bending mode of a clamped beam at both ends. The storage modulus value at 23 ℃ in the dynamic viscoelastic spectrum thus obtained was set as the flexural modulus (G') of the base film 1.

[ ultraviolet transmittance of base film ]

The Ultraviolet (UV) transmittance of the base films 1(a) to (n) was measured using a spectrophotometer "V-670 DS" (product name) manufactured by Japan Spectroscopy. Specifically, the transmittance of parallel light at a wavelength of 365nm was measured.

[ elongation of base film ]

The substrate films 1(a) to (n) were subjected to elongation measurement in the MD direction and the TD direction using a tensile tester "minecatechnograph TG-5 kN" (product name) manufactured by sabethan sumac based on the method specified in JIS Z0237 (2009).

2. Preparation of adhesive composition solution

As the adhesive composition for the adhesive layer 2 of the dicing tape 10, solutions of the following active energy ray-non-curable acrylic adhesive compositions (a) and (b) and active energy ray-curable acrylic adhesive compositions (c) and (d) were prepared.

(solution of adhesive composition 2 (a))

As the comonomer components, Methyl Methacrylate (MMA), 2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), and Acrylic Acid (AA) were prepared. These comonomer components were mixed at a copolymerization ratio of MMA/2-EHA/2-HEA/AA of 56 mass%/39 mass%/3 mass%/2 mass%, and solution radical polymerization was performed using ethyl acetate as a solvent and Azobisisobutyronitrile (AIBN) as an initiator to synthesize a base polymer solution (a) having hydroxyl groups and acid groups (solid content concentration: 35 mass%, weight average molecular weight Mw: 41 ten thousand).

Then, an epoxy-based crosslinking agent (trade name: TETRAD-X, solid content: 100% by mass) produced by Mitsubishi gas chemical was added as a crosslinking agent at a ratio of 0.3 part by mass (0.3 part by mass in terms of solid content) to 286 parts by mass (100 parts by mass in terms of solid content) of the synthesized base polymer solution (A), and the mixture was diluted with ethyl acetate and stirred to prepare a solution of the active energy ray-non-curable acrylic pressure sensitive adhesive composition 2(a) having a solid content of 22.6% by mass.

(solution of adhesive composition 2 (b))

The base polymer solution (a) used in the solution of the adhesive composition 2(a) was mixed with an isocyanate-based crosslinking agent (trade name: Coronate L, solid content concentration: 75 mass%) manufactured by tokoa as a crosslinking agent at a ratio of 2.7 parts by mass (2.0 parts by mass in terms of solid content) to 286 parts by mass (100 parts by mass in terms of solid content) of the base polymer solution (a), and the mixture was diluted with ethyl acetate and stirred to prepare an active energy ray non-curable acrylic adhesive composition 2(b) having a solid content of 22.6 mass%.

(adhesive composition 2(c))

2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), and Methyl Methacrylate (MMA) were prepared as comonomer components. These comonomer components were mixed at a copolymerization ratio of 75% by mass/20% by mass/5% by mass of 2-EHA/2-HEA/MMA, and solution radical polymerization was performed using ethyl acetate as a solvent and Azobisisobutyronitrile (AIBN) as an initiator, thereby synthesizing a base polymer solution having a hydroxyl group.

Then, 16 parts by mass of 2-isocyanatoethyl Methacrylate (MOI) having an isocyanate group and an active energy ray-reactive carbon-carbon double bond as an active energy ray-reactive compound was added to 100 parts by mass of the solid content of the base polymer, and reacted with a part of the hydroxyl groups of 2-HEA to synthesize an acrylic adhesive polymer solution (C) having a carbon-carbon double bond in the side chain (solid content concentration: 35% by mass, weight average molecular weight Mw: 55 ten thousand, carbon-carbon double bond content: 0.89 meq/g). In the above reaction, 0.05 part by mass of hydroquinone monomethyl ether was used as a polymerization inhibitor.

Then, 0.7 parts by mass of an acylphosphine oxide photopolymerization initiator (trade name: Omnirad819) as a photopolymerization initiator and 5.3 parts by mass of an isocyanate crosslinking agent (trade name: Coronate L, solid content concentration: 75% by mass) as a crosslinking agent (4.0 parts by mass in terms of solid content) as a crosslinking agent were mixed with 286 parts by mass (100 parts by mass in terms of solid content) of the acrylic adhesive polymer solution (C) synthesized as described above in such proportions that the solution was diluted with ethyl acetate and stirred to prepare an active energy ray-curable acrylic adhesive composition 2(C) having a solid content concentration of 22.6% by mass.

(adhesive composition 2(d))

2-ethylhexyl acrylate (2-EHA), 2-hydroxyethyl acrylate (2-HEA), Methyl Methacrylate (MMA), and N-vinyl-2-pyrrolidone (NVP) were prepared as comonomer components. These comonomer components were mixed at a copolymerization ratio of 2-EHA/2-HEA/MMA/NVP of 50 mass%/3 mass%/37 mass%/10 mass%, and solution radical polymerization was performed using ethyl acetate as a solvent and Azobisisobutyronitrile (AIBN) as an initiator to synthesize a base polymer solution (D) having a hydroxyl group (solid content concentration: 35 mass%, weight average molecular weight Mw: 50 ten thousand).

Next, 286 parts by mass (100 parts by mass in terms of solid content) of the base polymer solution (D) synthesized above, 120 parts by mass of an ultraviolet-curable urethane acrylate oligomer (weight average molecular weight Mw: 1,000, hydroxyl value: 1mgKOH/g, double bond equivalent: 167), 1.0 part by mass of an α -aminoalkylbenzophenone photopolymerization initiator (trade name: Omnirad369) manufactured by IGM Resins B.V. as a photopolymerization initiator, and 10 parts by mass (7.5 parts by mass in terms of solid content) of an isocyanate-based crosslinking agent (trade name: Coronate L, solid content concentration: 75% by mass) manufactured by Tosoh Corp.) as a crosslinking agent were mixed at the following ratios, diluted with ethyl acetate and stirred, thus, an active energy ray-curable acrylic adhesive composition 2(d) having a solid content of 22.6 mass% was prepared.

3. Preparation of adhesive composition solution

As an adhesive composition for the die attach film (adhesive layer) 3 of the dicing die attach film 20, a solution of the following adhesive composition 3(a) was prepared.

(solution of adhesive composition 3 (a))

First, a resin composition comprising 55 parts by mass of a cresol novolak type epoxy resin (trade name: YDCN-703, epoxy equivalent: 210, molecular weight: 1,200, softening point: 80 ℃) available from Tokyo chemical Co., Ltd., a thermosetting resin, 45 parts by mass of a phenol resin (trade name: MILEX XLC-LL, hydroxyl equivalent: 175, water absorption: 1.8%) available from Mitsui chemical Co., Ltd., a crosslinking agent, 1.7 parts by mass of gamma-mercaptopropyltrimethoxysilane (trade name: NUC A-189) available from Unica, Japan, as a silane coupling agent, 3.2 parts by mass of gamma-ureidopropyltriethoxysilane (trade name: NUCA-1160) available from Unica, Japan, and 32 parts by mass of silica (trade name: AEROSIL R972, average particle diameter 0.016. mu.m) available from Japan, AEROSIL Co., Ltd., a filler was used, cyclohexanone as a solvent was added to the mixture, and the mixture was stirred and mixed, and further dispersed for 90 minutes using a bead mill.

Next, 280 parts by mass of a glycidyl group-containing (meth) acrylate copolymer (trade name: HTR-860P-3, glycidyl (meth) acrylate content: 3% by mass, weight average molecular weight Mw: 80 ten thousand) as a thermoplastic resin and 0.5 part by mass of 1-cyanoethyl-2-phenylimidazole (trade name: CURIZOL 2PZ-CN) as a curing accelerator were added to the above resin composition, and the mixture was stirred, mixed and vacuum-released to prepare a solution of the adhesive resin composition 3(a) having a solid content of 20% by mass.

< cutting band 10 >

(example 1)

A roll (300mm wide) of the dicing tape 10(a) was produced by the following procedure using the substrate film 1(a) as the substrate film 1 and using the solution of the adhesive composition 2(a) as the solution of the adhesive composition for forming the adhesive layer 2.

The solution of the adhesive composition 2(a) was applied to the release-treated surface side of the release liner (polyethylene terephthalate film having a thickness of 38 μm) so that the thickness of the dried adhesive layer 2 became 30 μm, and the dried adhesive layer was heated at 100 ℃ for 3 minutes to dry the solvent, and then the base film 1(a) was laminated on the adhesive layer 2 to prepare a roll of the dicing tape 10 (a). Then, the roll of the dicing tape 10(a) was stored at 40 ℃ for 72 hours to crosslink and cure the adhesive layer 2. The coil of the dicing tape 10(a) of the present example was produced through the above steps. In the case of preparing a sample for dicing of the semiconductor wafer 30 having a diameter of 8 inches, which will be described later, the dicing tape 10(a) including the release liner prepared as described above was cut into a circular shape having a diameter of 290mm together with the release liner.

(examples 2 to 13)

A roll of dicing tapes 10(b) to (m) was produced in the same manner as in example 1, except that the type of the base film 1, the type of the adhesive composition for forming the adhesive agent layer 2, and the thickness of the adhesive agent layer 2 were changed as appropriate, as shown in table 1, relative to example 1. When the base film 1 is formed by lamination, the 1 st layer side surface of the base film 1 is bonded to the adhesive layer 2.

Comparative examples 1 to 4

A roll of dicing tapes 10(n) to (q) was produced in the same manner as in example 12, except that the type of the base film 1, the type of the adhesive composition for forming the adhesive agent layer 2, and the thickness of the adhesive agent layer 2 were changed as appropriate, as shown in table 1, relative to example 12. When the base film 1 is formed by lamination, the 1 st layer side surface of the base film 1 is bonded to the adhesive layer 2.

< chip adhesive film for dicing 20 >

(example 14)

First, a roll of the dicing tape 10 was produced in the same manner as in example 1, using the base film 1(d) as the base film 1 and using the solution of the adhesive composition 2(c) as the solution of the adhesive composition for forming the adhesive layer 2.

Next, a solution of the adhesive resin composition 3(a) for forming the die attach film (adhesive layer) 3 was prepared, the solution of the adhesive resin composition 3(a) was applied to the release-treated surface side of the release liner (polyethylene terephthalate film having a thickness of 38 μm) so that the thickness of the dried die attach film (adhesive layer) 3 became 25 μm, and the solution was heated at 140 ℃ for 5 minutes to dry the solvent, thereby producing the die attach film (adhesive layer) 3 provided with the release liner.

Next, the chip adhesive film (adhesive layer) 3 provided with the release liner prepared above and the release liner were cut into a circular shape having a diameter of 220mm, and the adhesive layer surface of the chip adhesive 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 40 ℃, 10 mm/sec, and a linear pressure of 30 kgf/cm.

Finally, the dicing tape 10 was cut into a circular shape having a diameter of 290mm, and a dicing die attach film 20(a) was produced in which a circular die attach film (adhesive layer) 3 having a diameter of 220mm was laminated on the upper center portion of the adhesive layer 2 of the circular dicing sheet 10 having a diameter of 290 mm.

(examples 15 to 19)

In the same manner as in example 14 except for appropriately changing the type of the base film 1, the type of the adhesive composition for forming the adhesive agent layer 2, and the thickness of the adhesive agent layer 2 as shown in table 1, the dicing die attach films 20(b) to (f) were produced in comparison with example 14. When the base film 1 is formed by lamination, the 1 st layer side surface of the base film 1 is bonded to the adhesive layer 2.

Comparative examples 5 to 8

In the same manner as in example 14 except that the type of the base film 1 was changed as shown in table 1 with respect to example 14, dicing die attach films 20(g) to (j) were produced. When the base film 1 is formed by lamination, the 1 st layer side surface of the base film 1 is bonded to the adhesive layer 2.

4. Dicing tape and method for evaluating die attach film for dicing

The dicing tapes 10 produced in examples 1 to 13 and comparative examples 1 to 4, and the dicing die bonding films 20 produced in examples 14 to 19 and comparative examples 5 to 9 were measured and evaluated for the separability after dicing of the semiconductor wafer 30, the dicing characteristics, which are the states of chipping of the base film, and the pick-up properties of the semiconductor chip 30a as follows.

4.1 post-dicing separability of semiconductor wafers

First, a back-grinding protective tape was attached to the surface of a semiconductor wafer having a diameter of 8 inches using a back-grinding apparatus "DAG-810" (product name) manufactured by Dikesco, Ltd, and then the wafer was ground to obtain a semiconductor wafer (mirror wafer) 30 having a thickness of 50 μm.

Each dicing sample as shown in fig. 7(a) was prepared by bonding the adhesive layer 2 surface of the dicing tape 10 from which the release liner was peeled to the surface (polishing surface side) of the semiconductor wafer 30 having a thickness of 50 μm to the dicing tapes 10(a) to (q) of examples 1 to 13 and comparative examples 1 to 4 which were cut into a circular shape having a diameter of 290mm, and bonding the ring frame 40 to the outer peripheral portion of the adhesive layer 2 surface of the dicing tape 10. At this time, the protective tape for back grinding of the semiconductor wafer 30 is already peeled off.

Further, dicing die attach films 20(a) to (j) in which a circular die attach film (adhesive layer) 3 having a diameter of 220mm was laminated on the upper center portion of the adhesive layer 2 of a circular dicing sheet 10 having a diameter of 290mm were prepared by bonding the die attach film (adhesive layer) 3 surface of the dicing die attach film 20 from which the release liner was peeled to the surface of a semiconductor wafer 30 having a thickness of 50 μm at a hot plate temperature of 70 ℃, and bonding a ring frame 40 to the outer peripheral portion of the adhesive layer 2 surface of the dicing tape 10 portion of the dicing die attach film 20, to prepare each dicing sample as shown in fig. 8 (a). At this time, the protective tape for back grinding of the semiconductor wafer 30 is already peeled off.

Next, the sample for cutting was cut by a full-cut cutting method using a full-automatic cutter "DFD-6361" (product name) manufactured by Decidesco, Ltd. The cutting conditions were 40,000rpm in blade rotation number, 50 mm/sec in cutting speed, and 5mm × 5mm in chip size, and cutting was performed so as to cut the base film 1 by a depth of 5 μm as shown in fig. 7(c) and 8 (c). In the dicing step, flowing water was continuously supplied to the rotating blade and the semiconductor wafer, and cooling was performed (water supply amount: 1 liter/minute, water temperature: 25 ℃).

After the semiconductor wafer 30 was diced using the dicing tapes 10 produced in examples 1 to 13 and comparative examples 1 to 4 and the dicing die bonding films 20 produced in examples 14 to 19 and comparative examples 5 to 9, the four sides of the cut semiconductor chip 30a were observed from the front surface of the semiconductor wafer 30 using an optical microscope "VHX-1000" (product name) manufactured by keyence corporation, and the divided state of the semiconductor wafer 30 was evaluated based on a photograph magnified 150 times in magnification. Specifically, it was evaluated whether all the semiconductor chips 30a, which were singulated in a size of 5mm × 5mm, could be divided neatly and independently without breaking.

The separability of the semiconductor wafer after dicing was evaluated according to the following criteria. Note that the evaluation of a is defined as pass.

A: all chips were independent without breaking (forming a notch)

C: there are chips that are broken or chips that have cutouts that are not sufficiently formed and adjacent chips are in contact with each other

4.2 chipping generation status of substrate film after semiconductor wafer dicing

After dicing the semiconductor wafer 30 using the dicing tapes 10 produced in examples 1 to 13 and comparative examples 1 to 4 and the dicing die attach films 20 produced in examples 14 to 19 and comparative examples 5 to 9, the degree of the amount of chips adhering to 5 predetermined portions of the surface of the semiconductor wafer 30 was observed on the basis of a photograph magnified 150 times with a magnification using an optical microscope "VHX-1000" (product name) manufactured by keywayama corporation. Specifically, the number of filament-like chips having a length of 50 μm or more is counted for each of predetermined 5 portions of the semiconductor wafer having undergone the dicing step, and the total number of filament-like chips in the 5 portions is divided by 5 (the average number of chips) to calculate a value. The predetermined 5 portions are cross portions including one cross portion (central portion) closest to the intersection of the semiconductor wafer and four intersection portions (upper, lower, left and right portions) located in the layer in contact with the adhesive layer and separated from each other at 90-degree intervals in the circumferential direction of the semiconductor wafer, among the intersections of the dividing grooves (dicing lines) formed by dicing.

The generation state of chips in the base material film after dicing of the semiconductor wafer was evaluated according to the following criteria. Note that the evaluation of a or B is defined as pass.

A: the average number of the filiform cutting chips is more than 0 and less than 1

B: the average number of the filiform cutting chips is more than 1 and less than 10

C: the average number of the filiform cutting chips is more than 10

4.3 evaluation of the pickup Property of semiconductor chip

After the semiconductor wafer 30 was diced using the dicing tapes 10 produced in examples 1 to 13 and comparative examples 1 to 4 and the dicing die bonding films 20 produced in examples 14 to 19 and comparative examples 5 to 9, the dicing tapes 10 and the dicing die bonding films 20 were spread so as to increase the distance between the semiconductor chips 30 a. In the case of using an active energy ray-curable acrylic adhesive composition as the adhesive composition of the adhesive layer 2, the cumulative irradiation light amount 300mJ/cm was irradiated to the adhesive layer 2 from the substrate film 1 side before expansion²The adhesive layer 2 is crosslinked and cured by Ultraviolet (UV) rays of (a). When an active energy ray non-curable acrylic adhesive composition is used as the adhesive composition of the adhesive layer 2, spreading is performed without irradiation of ultraviolet rays (UV). In the expanding step, the expanding speed (the speed at which the hollow cylindrical push-up member ascends) was set to 30 mm/sec, and the expanding amount (the distance at which the hollow cylindrical push-up member ascends) was set to 9 mm.

The semiconductor chips 30a in which the distance between the semiconductor chips 30a singulated on the dicing tape 10 and the dicing die bonding film 20 by the extending step was extended were subjected to a pickup test using a pickup device "WCS-700" (product name) manufactured by shinko electronics co. The collet of the pickup used has, for example, a push-up face of 4.5mm × 4.5mm, and 5 push-up pins 60 are arranged at predetermined intervals along the diagonal of the push-up face. Regarding the pickup conditions, the push-up speed is set to 5 mm/sec, and the push-up height is changed in the range of 350 to 500 μm at every 50 μm. Note that the pickup condition is a condition in a range where there is no problem in actual use.

Then, in each of the push-up levels, the number of samples of the semiconductor chips 30a is set to 20 of the predetermined positions, and the number of semiconductor chips 30a that can be picked up by the suction collet 50 without damage is counted.

The pick-up property of the semiconductor chip 30a was evaluated at each push-up height according to the following criteria.

A: the success rate of the semiconductor chip was 20 (success rate 100%)

B: the number of successful picking-up of semiconductor chips is 18 to 20 (success rate 90% to 100%)

C: the number of successful picking-up of semiconductor chips is 16 or more and less than 18 (success rate 80% or more and less than 90%)

D: the success rate of the semiconductor chip is less than 16 (the success rate is less than 80%)

As a comprehensive evaluation of the above-described pickup test, the smaller the amount of the push-up height of the push-up pin of a or B is evaluated as the number of successful pickups of the semiconductor chip, the more excellent the pickup property of the dicing tape 10 or the dicing die attach film 20 is judged.

5. Evaluation results

The evaluation results of the dicing tapes 10 produced in examples 1 to 13 and comparative examples 1 to 4 and the dicing die bonding films 20 produced in examples 14 to 19 and comparative examples 5 to 9 are shown in tables 1 to 7 in combination with the structures of the dicing tapes 10 and the dicing die bonding films 20, the structure of the base film 1 used, and the like.

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

[ Table 5]

[ Table 6]

[ Table 7]

First, as shown in tables 1 to 4, it was confirmed that the dicing tapes 10(a) to (m) of examples 1 to 13 using the base material films 1(a) to (j) satisfying the requirements of the present invention each obtained preferable results in any evaluation of the dicing characteristics and the pickup properties.

When the examples are compared in detail, it is understood that the dicing tapes 10 of examples 1 to 3, 5 and 6, and 10 to 13 using the base film 1 having the flexural modulus (G ') in the range of 17MPa to 115MPa are superior to the dicing tapes 10 of examples 4 and 9, and 7 and 8 using the base films 1 having the flexural moduli (G') of 10.4MPa, 118.5MPa, and 133.9MPa in the evaluation of the dicing characteristics (suppression of chips) and the pick-up properties (minimum push-up height at which the pick-up success rate reaches 100%), and can be compatible with each other, and are superior to each other. That is, the dicing tapes 10 of examples 4 and 9 using the base film 1 having a flexural modulus (G') of 10.4MPa had a slightly lower effect of suppressing chips during dicing than the dicing tapes 10 of the other examples. In the dicing tapes 10 of examples 7 and 8 using the base material films 1 having flexural elastic moduli (G') of 118.5MPa and 133.9MPa, respectively, the minimum push-up height of 400 μm at which the pickup success rate reached 100% in the pickup test was larger than 350 μm of the dicing tape 10 of the other example by 50 μm, and the pickup was slightly inferior, compared to the dicing tape 10 of the other example.

On the other hand, as shown in table 4, it was confirmed that the dicing tapes 10(n) to (q) of comparative examples 1 to 4 using the base material films 1(k) to (n) that do not satisfy the requirements of the present invention were inferior to the dicing tapes 10(a) to (m) of examples 1 to 13 in at least any evaluation of the dicing characteristics and the pickup properties.

Specifically, the dicing tape 10(n) of comparative example 1 using the base material film 1(k) made of the polyolefin resin having the flexural modulus of elasticity (G ') of 146.5MPa and exceeding the upper limit of the range of the flexural modulus of elasticity (G') of the present invention (2 resins, 3 layers) had good effects of cutting-off and chip suppression, but in the pickup test, the pickup success rate did not reach 100% at any push-up height in a predetermined range, and in particular, many pickup errors due to chip breakage were observed at any time when the push-up height reached 450 μm or more, and the pickup property was significantly deteriorated as compared with the dicing tape 10 of example.

In addition, the dicing tape 10(o) of comparative example 2 using the base film 1(l) composed of the polyolefin resin having the flexural modulus of elasticity (G ') of 413.0MPa and exceeding the upper limit value of the range of the flexural modulus of elasticity (G') of the present invention (2 types of resins, 3 layers), although the splittability at the time of dicing is good, since the crystal melting point of the PE of the 1 st layer (the one surface side in contact with the adhesive layer 2) having the 1 st surface of the base film 1 is low, generation and adhesion of many cutting chips at the time of dicing are observed everywhere, and the effect of suppressing the cutting chips at the time of dicing is inferior to that of the dicing tape 10 of example. Further, in the pickup test, the success rate of the pickup was not 100% at any push-up height in a predetermined range, and many pickup errors due to chip peeling failure or chip breakage were observed everywhere, and the pickup was greatly deteriorated as compared with the dicing tape 10 of the example.

Further, the dicing tape 10(p) of comparative example 3 using the base film 1(m) made of the thermoplastic polyester elastomer of the PBT/PTMG copolymer having the flexural modulus (G ') of 159.7MPa, which is out of the upper limit value of the range of the flexural modulus (G') of the present invention, had the same evaluation result as that of comparative example 1 in the pick-up test, though the cutting performance and the effect of suppressing the chips were good, and the pick-up performance was greatly deteriorated as compared with the dicing tape 10 of the example.

Further, the dicing tape 10(q) of comparative example 4 using the base material film 1(n) made of the thermoplastic polyester elastomer of the PBT/PTMG copolymer having the flexural modulus (G ') of 218.7MPa, which is beyond the upper limit value of the range of the flexural modulus (G') of the present invention, was excellent in the cutting-time splittability and the effect of suppressing chips, but had the same evaluation result as that of comparative example 2 in the pick-up test, and the pick-up property was significantly deteriorated as compared with the dicing tape 10 of the example.

Next, as shown in tables 5 to 7, it was confirmed that preferable results were obtained in any evaluation of the dicing characteristics and the pickup properties also for the dicing die bonding films 20(a) to (f) of examples 14 to 19 using the base films 1(a), (c) to (e), and (h) satisfying the requirements of the present invention.

When the examples are compared in detail, it is understood that the dicing die attach films 20 of examples 15, 16 and examples 18, 19 using the base film 1 having the flexural modulus (G ') in the range of 17MPa to 115MPa are superior to the dicing die attach films 20 of examples 14 and 17 using the base films 1 having the flexural moduli (G') of 10.4MPa and 133.9MPa in the evaluation of the dicing characteristics (suppression of chips) and the pick-up characteristics (minimum push-up height at which the pick-up success rate reaches 100%), and can achieve both high levels and a good balance. That is, the dicing die bonding film 20 of example 14 using the base film 1 having a flexural modulus (G') of 10.4MPa had a slightly lower effect of suppressing the cutting chips than the dicing die bonding films 20 of the other examples. The dicing die bonding film 20 of example 17 using the base film 1 having a flexural modulus (G') of 133.9MPa had a lowest push-up degree of 400 μm, which was 100% of the pickup success rate, and was 50 μm larger than 350 μm of the dicing die bonding film 20 of the other examples, and the pickup property was slightly inferior to that of the dicing die bonding film 20 of the other examples.

On the other hand, as shown in tables 6 and 7, it was confirmed that the dicing die attach films 20(g) to (j) of comparative examples 5 to 8 using the base material films 1(k) to (n) that do not satisfy the requirements of the present invention were inferior to the dicing die attach films 20(a) to (f) of examples 14 to 19 in at least any evaluation of the dicing characteristics and the pickup properties.

Specifically, the dicing die bonding film 20(G) of comparative example 5 using the base material film 1(k) made of the polyolefin resin having the flexural modulus (G ') of 146.5MPa and exceeding the upper limit of the range of the flexural modulus (G') of the present invention (2 resins, 3 layers), had good effects of cutting and chip suppression, but had a pickup success rate of not 100% at any push-up height in a predetermined range in the pickup test, and in particular, many pickup errors due to chip breakage were observed at any time when the push-up height reached 450 μm, and the pickup property was significantly deteriorated as compared with the dicing die bonding film 20 of the example.

Further, the dicing die bonding film 20(h) of comparative example 6 using the base film 1(l) composed of the polyolefin resin having a flexural modulus (G ') of 413.0MPa and exceeding the upper limit value of the range of the flexural modulus (G') of the present invention and consisting of PE/PP/PE (2 resins, 3 layers) had good separability at the time of dicing, but since the crystal melting point of PE of the 1 st layer (the one surface side in contact with the adhesive layer 2) having the 1 st surface of the base film 1 was low, generation and adhesion of many cutting chips at the time of dicing were observed everywhere, and the effect of suppressing the cutting chips at the time of dicing was inferior to that of the dicing die bonding film 20 of the example. Further, in the pickup test, the pickup success rate did not reach 100% at any push-up height in the predetermined range, and many pickup errors due to chip peeling failure or chip breakage were observed everywhere, and the pickup property was greatly deteriorated as compared with the dicing die attach film 20 of the embodiment.

Further, the dicing die bonding film 20(i) of comparative example 7 using the base film 1(m) made of the thermoplastic polyester elastomer of the PBT/PTMG copolymer having the flexural modulus (G ') of 159.7MPa, which is out of the upper limit value of the range of the flexural modulus (G') of the present invention, had the same evaluation result as that of comparative example 5 in the pickup test, and the pickup property was significantly deteriorated as compared with the dicing die bonding film 20 of the example, although the effect of suppressing the cutting chips and the cuttability at the time of dicing were good.

Further, the dicing die bonding film 20(q) of comparative example 8 using the base film 1(n) made of the thermoplastic polyester elastomer of the PBT/PTMG copolymer having a flexural modulus (G ') of 218.7MPa which is out of the upper limit value of the range of the flexural modulus (G') of the present invention was excellent in the cutting-time dividing property and the effect of suppressing the cutting chips, but had the evaluation results on the same level as those of comparative example 6 in the pick-up test, and the pick-up property was significantly inferior to that of the dicing die bonding film 20 of the example.

Claims (11)

1. A substrate film for dicing tape, having a 1 st face on which an adhesive layer is formed and a 2 nd face opposite to the 1 st face,

comprising a resin containing a thermoplastic polyester elastomer which is a block copolymer comprising a hard segment (A) mainly composed of a polyester composed of an aromatic dicarboxylic acid and an aliphatic diol or an alicyclic diol, and a soft segment (B) mainly composed of an aliphatic polyether,

the base film has a bending elastic modulus G' at 23 ℃ in the range of 10MPa to 135MPa when the dynamic viscoelasticity is measured in a clamped beam bending mode at a frequency of 1Hz and a temperature rise rate of 0.5 ℃/min.

2. The substrate film according to claim 1, wherein the substrate film has a flexural elastic modulus G' at 23 ℃ in a range of 17MPa or more and 115MPa or less.

3. The substrate film according to claim 1 or 2, wherein the soft segment (B) has a content, i.e., a copolymerization amount, in a range of 51 mass% or more and 73 mass% or less with respect to the total mass of the hard segment (a) and the soft segment (B).

4. The substrate film according to claim 1 or 2, wherein the soft segment (B) has a content, i.e., a copolymerization amount, in a range of 55 mass% or more and 70 mass% or less with respect to a total mass of the hard segment (a) and the soft segment (B).

5. The substrate film according to any one of claims 1 to 4, wherein the hard segment (A) is polybutylene terephthalate (PBT).

6. The substrate film according to any of claims 1 to 5, wherein the soft segment (B) is a poly (oxytetramethylene) glycol (PTMG) and/or a poly (propylene oxide) glycol ethylene oxide addition polymer (PPG-EO addition polymer).

7. The substrate film according to any one of claims 1 to 6, wherein the substrate film is composed of a single resin layer, and the resin comprising the thermoplastic polyester elastomer constituting the layer has a crystalline melting point in a range of 160 ℃ or more and 200 ℃ or less.

8. The substrate film according to any one of claims 1 to 6, wherein the substrate film is composed of a plurality of resin layers laminated, and the resin including the thermoplastic polyester elastomer constituting the layer having the 1 st surface has a crystal melting point in a range of 160 ℃ to 200 ℃.

9. The substrate film according to any one of claims 1 to 8, wherein the thickness is in a range of 70 μm or more and 155 μm or less.

10. The substrate film according to any one of claims 1 to 9, wherein the elongation is in a range of 300% to 700%.

11. A dicing tape comprising the substrate film according to any one of claims 1 to 10 and an adhesive layer formed on the surface thereof.

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