Manufacturing method of semiconductor chip

Abstract

To provide a manufacturing method of a semiconductor chip, capable of improving a pick-up property of bonding-layer-attached semiconductor chips.SOLUTION: A manufacturing method of a semiconductor chip comprises: a wafer individualization step of forming a plurality of semiconductor chips 3 by individualizing a semiconductor wafer W on a bonding layer 14 of a lamination film 11 in which a substrate layer 12, an adhesive layer 13 and the bonding layer 14 are laminated in this order; an adhesive layer individualization step of forming a plurality of bonding-layer-attached semiconductor chips 16 by irradiating a laser beam L to the bonding layer 14 via gaps between the plurality of semiconductor chips 3 and 3 to individualize the bonding layer 14; and an expansion step of expanding the substrate layer 12 so that fragments P of the adhesive layer 13 and bonding layer 14 produced due to an irradiation of the laser beam L are segmented between the bonding-layer-attached semiconductor chips 16, 16, respectively.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a method for manufacturing semiconductor chips. [Background technology]

[0002] In recent years, as semiconductor packages have become thinner, the semiconductor chips incorporated in the semiconductor packages have also become thinner. However, as semiconductor chips become thinner, defects such as breakage during processing become more likely to occur, and therefore the manufacturing process is beginning to change from conventional processes.

[0003] As a process for suppressing defects caused by thinning of semiconductor chips, for example, a dicing before grinding (DBG) process is known. In the DBG process, a dicing process is performed on a semiconductor wafer along a predetermined dicing line, and then a back-grinding process is performed on the semiconductor wafer. In the dicing process, grooves are formed on one side of the semiconductor wafer by half-cut dicing, and in the back-grinding process, the other side of the semiconductor wafer is ground until it reaches the groove, thereby simultaneously thinning and dividing the semiconductor wafer (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2016 / 189986 [Patent Document 2] JP 2011-181951 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the process following the DBG process, a laminated film in which a dicing film and a die attachment film are integrated may be used. This laminated film has a structure in which, for example, a dicing film made of a base material layer and an adhesive layer is laminated with a die attachment film made of an adhesive layer.

[0006] When a laminated film is used, the adhesive layer side of the laminated film is attached to an individualized semiconductor wafer, and a laser beam for processing is irradiated along the same line as the dicing line to make an incision in the die attachment film corresponding to the individualized semiconductor wafer. After making the incision in the die attachment film, the dicing tape is expanded in the in-plane direction to individualize the die attachment film. Then, the individualized semiconductor wafer and die attachment film are picked up from the dicing tape to obtain a semiconductor chip with an adhesive layer.

[0007] However, in the above-mentioned semiconductor chip manufacturing method, there are cases where the semiconductor chip with the adhesive layer cannot be picked up sufficiently from the dicing tape, and there are also cases where cracks occur in the semiconductor chip with the adhesive layer during pick-up.

[0008] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a method for manufacturing a semiconductor chip that improves the pick-up ability of a semiconductor chip with an adhesive layer and suppresses cracks. [Means for solving the problem]

[0009] The gist of this disclosure is as follows: [1] to [7] [1] A method for manufacturing a semiconductor chip, comprising: a wafer singulation process for forming a plurality of semiconductor chips by singulating a semiconductor wafer on the adhesive layer of a laminated film in which a base layer, an adhesive layer, and an adhesive layer are laminated in this order; an adhesive layer singulation process for irradiating the adhesive layer with laser light through gaps between the plurality of semiconductor chips to singulate the adhesive layer, thereby forming a plurality of semiconductor chips with an adhesive layer; and an expanding process for expanding the base layer such that fragments of the adhesive layer and the adhesive layer caused by the irradiation of the laser light are separated between adjacent semiconductor chips with an adhesive layer.

[0010] In this method for manufacturing a semiconductor chip, the adhesive layer is irradiated with a laser beam to separate the adhesive layer and the adhesive layer fragments formed by the laser beam irradiation are separated between adjacent semiconductor chips with the adhesive layer, and then the base layer is expanded so that the adhesive layer and the adhesive layer fragments formed by the laser beam irradiation are separated between adjacent semiconductor chips with the adhesive layer. If the adhesive layer and the adhesive layer fragments are adhered to each other between adjacent semiconductor chips with the adhesive layer, it is considered that the peel strength (edge ​​peel strength) at the edge of the semiconductor chip with the adhesive layer is maintained high. As a result, the pick-up property of the semiconductor chip with the adhesive layer is reduced, and cracks may occur in the semiconductor chip with the adhesive layer during pick-up. In contrast, in this method for manufacturing a semiconductor chip, the adhesive layer and the adhesive layer fragments are separated by expanding the base layer during pick-up, thereby reducing the edge peel strength of the semiconductor chip with the adhesive layer. Therefore, the pick-up property of the semiconductor chip with the adhesive layer can be improved, and the occurrence of cracks in the semiconductor chip with the adhesive layer during pick-up can be suppressed. [2] The method for producing a semiconductor chip according to [1], wherein the expanding step is performed by stretching the base material layer in an in-plane direction of the base material layer. In this case, the pieces of the adhesive layer and the bonding layer can be suitably separated from each other. [3] The method for manufacturing a semiconductor chip according to [1], further comprising a pick-up step of picking up the semiconductor chip with the adhesive layer from the base layer and the adhesive layer, and the expanding step is performed by pushing up the base layer with a needle at the pick-up position of the semiconductor chip with the adhesive layer in the pick-up step. In this case, the pieces of the adhesive layer and the adhesive layer can be suitably separated from each other. In addition, since the expanding step is also performed in the pick-up step, the process can be simplified. [4] The method for manufacturing a semiconductor chip according to any one of [1] to [3], wherein the expansion amount of the base layer is 4 mm or more. In this case, the pieces of the adhesive layer and the bonding layer can be separated more reliably, and the edge peel strength of the semiconductor chip with the adhesive layer can be further reduced. [5] The method for manufacturing a semiconductor chip according to any one of [1] to [4], wherein the expansion amount of the base layer is 7 mm or more. In this case, the pieces of the adhesive layer and the bonding layer can be separated more reliably, and the edge peel strength of the semiconductor chip with the adhesive layer can be further reduced. [6] The method for manufacturing a semiconductor chip according to any one of [1] to [5], wherein the expansion amount of the base layer is 10 mm or less. In this case, it is possible to suppress the application of excessive force due to the expansion to the base layer, and therefore to prevent damage to the base layer. [7] The method for manufacturing a semiconductor chip according to any one of [1] to [6], wherein the adhesive layer is made of an ultraviolet-curable adhesive, and a curing step is included in which the adhesive layer is irradiated with ultraviolet light before the laser light is irradiated to the adhesive layer to form a cured layer of the ultraviolet-curable adhesive. In this case, when the adhesive layer is divided into individual pieces by the laser light irradiation, the adhesive layer is already in a cured state, so that adhesion between the pieces of the adhesive layer can be suppressed. Therefore, the edge peel strength of the semiconductor chip with the adhesive layer can be more effectively reduced. Effect of the Invention

[0011] According to the present disclosure, the pick-up properties of a semiconductor chip with an adhesive layer are improved. [Brief description of the drawings]

[0012] [Figure 1] 1A to 1D are schematic cross-sectional views showing a method for manufacturing a semiconductor chip according to an embodiment of the present disclosure, in which (a) to (d) are views showing a wafer singulation process in order of steps. [Diagram 2] 2A and 2B are schematic cross-sectional views showing steps subsequent to those in FIG. 1, in which (a) and (b) show the curing step in the order of steps. [Diagram 3] 3A and 3B are schematic cross-sectional views showing steps subsequent to those in FIG. 2, in which (a) and (b) are views showing an adhesive layer singulation step in the order of steps. [Figure 4] 5A and 5B are schematic cross-sectional views showing subsequent steps of FIG. 3, in which (a) shows adhesion between the adhesive layer and the pieces of the adhesive layer between adjacent semiconductor chips with adhesive layers after the adhesive layer singulation step, and (b) shows an expansion step. [Diagram 5] 5A and 5B are schematic cross-sectional views showing steps subsequent to those in FIG. 4, in which (a) shows a pick-up step, and (b) shows a bonding step. [Figure 6] FIG. 11 is a schematic cross-sectional view showing a modified example of the expanding step. [Figure 7] 1(a) and 1(b) are diagrams showing an evaluation test of peel strength. [Figure 8] FIG. 13 is a diagram showing the results of an evaluation test of peel strength. [Figure 9] FIG. 13 is a diagram showing the results of an evaluation test of pick-up properties. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, a preferred embodiment of a method for manufacturing a semiconductor chip according to one aspect of the present disclosure will be described in detail with reference to the drawings.

[0014] In this specification, a numerical range indicated using "~" includes the numerical values ​​before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper limit or lower limit value described in one numerical range may be replaced with the upper limit or lower limit value of another numerical range described in stages. In numerical ranges described in this specification, the upper limit or lower limit value of the numerical range may be replaced with a value shown in the examples. Furthermore, the upper limit and lower limit values ​​described individually can be combined in any combination.

[0015] In this specification, the term "layer" includes not only a structure having a shape formed over the entire surface when observed in a plan view, but also a structure having a shape formed only in a portion of the surface. In this specification, the term "process" includes not only an independent process, but also a process that achieves the intended effect of the process even if it cannot be clearly distinguished from other processes.

[0016] In this specification, "(meth)acrylate" means at least one of acrylate and its corresponding methacrylate. The same applies to other similar expressions such as "(meth)acryloyl" and "(meth)acrylic acid". "(Poly)" refers to both the case with and without the "poly" prefix.

[0017] "A or B" means that either A or B is contained, or both are contained. Unless otherwise specified, the exemplified materials may be used alone or in combination of two or more. When a plurality of substances corresponding to each component are present in the composition, the content of each component in the composition means the total amount of the plurality of substances present in the composition, unless otherwise specified.

[0018] This semiconductor chip manufacturing method is a method of manufacturing a plurality of semiconductor chips 16 with adhesive layers by cutting a semiconductor wafer W into a predetermined pattern using a laminated film 11 (see FIG. 2(a)) having a base layer 12, an adhesive layer 13, and an adhesive layer 14. In this embodiment, the semiconductor chip manufacturing method includes a wafer singulation process (step S01), a curing process (step S02), an adhesive layer singulation process (step S03), an expanding process (S04), and a pick-up process (S05).

[0019] The wafer singulation process S01 is a process for forming a plurality of semiconductor chips 3 by singulating the semiconductor wafer W on the adhesive layer 14 of the laminated film 11. In the wafer singulation process S01, as shown in FIG. 1(a), first, a semiconductor wafer W is prepared and a dicing process is performed. In the dicing process, grooves Ws are formed on the circuit formation surface of the semiconductor wafer W along dicing lines. Examples of materials constituting the semiconductor wafer W include single crystal silicon, polycrystalline silicon, various ceramics, and compound semiconductors such as gallium arsenide.

[0020] The semiconductor wafer W has a circuit-forming surface Wa and a back surface Wb opposite to the circuit-forming surface Wa. The thickness of the semiconductor wafer W is greater than the thickness of the semiconductor chips 3 obtained in the wafer singulation step S01. The thickness of the semiconductor wafer W may be, for example, 50 to 3000 μm, 100 to 2000 μm, or 200 to 1500 μm.

[0021] Here, for example, a dicing blade B is used to perform half-cut dicing on the circuit forming surface Wa of the semiconductor wafer W. In half-cut dicing, grooves Ws are formed to a depth less than the thickness of the semiconductor wafer W so as not to completely cut the semiconductor wafer W. The grooves Ws are formed on the circuit forming surface Wa of the semiconductor wafer W so as to form a lattice pattern in a plan view of the semiconductor wafer W, for example.

[0022] After the dicing process, a backgrinding process is performed. In the backgrinding process, as shown in FIG. 1(b), first, a backgrinding tape 1 is attached to the circuit forming surface Wa on which the grooves Ws are formed. As the backgrinding tape 1, a general backgrinding tape used in the relevant field can be used. The backgrinding tape 1 may be, for example, a backgrinding tape having an adhesive layer containing an ultraviolet-curing adhesive.

[0023] After the backgrind tape 1 is attached to the circuit formation surface Wa, the back surface Wb of the semiconductor wafer W is ground using a grinder 2 at least until it reaches the grooves Ws. The grooves Ws are exposed on the back surface Wb by grinding, and the semiconductor wafer W is divided into individual pieces, as shown in Fig. 1(c), and a plurality of semiconductor chips 3 arranged in a lattice pattern in a plan view are formed on the backgrind tape 1. Adjacent semiconductor chips 3, 3 are separated from each other by gaps G resulting from the grooves Ws.

[0024] After the semiconductor wafer W is diced, the adhesive layer 14 side of the laminated film 11 is attached to the back surface of the semiconductor chip 3 (the surface corresponding to the back surface Wb of the semiconductor wafer W). As shown in FIG. 1(d), the laminated film 11 is a film having a base layer 12, an adhesive layer 13, and an adhesive layer 14 in this order. The adhesive layer 13 is composed of an ultraviolet-curable adhesive, as described below. The base layer and the adhesive layer 13 are dicing films. The adhesive layer 14 is a die attachment film. In other words, the laminated film 11 is an integrated film of the dicing film and the die attachment film. A ring frame R is fixed to the peripheral edge of the dicing tape.

[0025] After the laminated film 11 is attached, the backgrind tape 1 is peeled off from the semiconductor chips 3. As a result, as shown in Fig. 1(d), the semiconductor chips 3, which are obtained by dicing the semiconductor wafer W, are formed on the adhesive layer 14 of the laminated film 11 in which the base layer 12, the adhesive layer 13, and the adhesive layer 14 are laminated in this order.

[0026] When the backgrind tape 1 has an adhesive layer containing an ultraviolet-curable adhesive, it is preferable to irradiate the adhesive layer of the backgrind tape 1 with ultraviolet light to cure the adhesive layer before peeling off the backgrind tape 1. This reduces the adhesive strength of the adhesive layer, making it possible to easily peel off the backgrind tape 1 from the multiple semiconductor chips 3.

[0027] The curing step S02 is a step of irradiating the adhesive layer 13 with ultraviolet light U to form a cured layer 15 of the ultraviolet-curable adhesive. The curing step S02 is performed before the adhesive layer singulation step S03, i.e., before the adhesive layer 14 is irradiated with laser light L. The ultraviolet light U is irradiated from the base layer 12 side, as shown in FIG. 2(a), for example. The irradiation with the ultraviolet light U forms a cured layer 15 including the cured product of the adhesive layer 13, as shown in FIG. 2(b). In the following description, the adhesive layer 13 will be referred to as it is, but when the adhesive layer 13 is cured by irradiation with ultraviolet light U, the adhesive layer 13 refers to the cured layer 15.

[0028] The irradiation source of the ultraviolet ray U is not particularly limited, and for example, a metal halide lamp, a high pressure sodium lamp, a UV-LED lamp, etc. can be used. The illuminance of the ultraviolet ray U on the adhesive layer 13 is, for example, 1 to 1000 mW / cm. 2 may be 10 to 900 mW / cm 2 30 to 800 mW / cm 2 The amount of ultraviolet light U irradiated onto the adhesive layer 13 may be, for example, 10 to 3000 mJ / cm 2 . 2 and may be 50 to 2500 mJ / cm 2 and may be 100 to 2000 mJ / cm 2 may be also possible.

[0029] The adhesive layer singulation step S03 is a step of forming a plurality of semiconductor chips 16 with an adhesive layer by singulating the adhesive layer 14. In the adhesive layer singulation step S03, as shown in FIG. 3(a), a laser beam L is irradiated onto the adhesive layer 14 through the gaps G between the plurality of semiconductor chips 3, 3 to singulate the adhesive layer 14. Since the gaps G are formed along the above-mentioned dicing lines, as shown in FIG. 3(b), the singulation of the adhesive layer 14 results in the formation of a plurality of semiconductor chips 16 with an adhesive layer arranged in a lattice pattern in plan view on the dicing tape. Note that the irradiation of the laser beam L is performed to a depth that reaches the adhesive layer 13 below the adhesive layer 14 in order to reliably cut the adhesive layer 14.

[0030] The irradiation of the laser light L can be performed using a known laser saw. The frequency of the laser light L may be, for example, 30 to 250 kHz, 50 to 200 kHz, or 80 to 120 kHz. The output of the laser light L may be, for example, 0.05 to 2.0 W, 0.1 to 1.0 W, or 0.2 to 0.5 W. The feed speed of the laser light L may be, for example, 20 to 500 mm / s, 50 to 400 mm / s, or 100 to 300 mm / s.

[0031] In the above-mentioned adhesive layer singulation step S03, the adhesive layer 14 is cut using laser light L, and cuts are also formed in the adhesive layer 13. Therefore, it is expected that the components of the adhesive layer 14 and the adhesive layer 13 will scatter when the laser light L is irradiated. If the components of the adhesive layer 14 and the adhesive layer 13 scatter and adhere or accumulate on the side surface of the semiconductor chip 16 with the adhesive layer, it is considered that the fragments P of the adhesive layer 13 and the adhesive layer 14 will adhere to each other between the adjacent semiconductor chips 16 with the adhesive layer, as shown in FIG. 4(a), for example.

[0032] When the fragments P of the adhesive layer 13 and the adhesive layer 14 adhere to each other between the adjacent semiconductor chips 16, 16 with the adhesive layer, it is considered that the peel strength (edge ​​peel strength) at the edge of the semiconductor chip 16 with the adhesive layer is maintained high. As a result, the pick-up property of the semiconductor chip 16 with the adhesive layer is reduced, and there is a risk that cracks may occur in the semiconductor chip 16 with the adhesive layer when it is picked up.

[0033] Therefore, in the manufacturing method of the semiconductor chip according to the present embodiment, in the expanding step S04 following the adhesive layer singulation step S03, the base layer 12 is expanded so that the fragments P of the adhesive layer 13 and the adhesive layer 14 caused by the irradiation of the laser light L are separated between the adjacent semiconductor chips 16, 16 with the adhesive layer. In the expanding step S04, for example, as shown in FIG. 4(b), a push-up member 18 is used to push up the formation region of the semiconductor chip 16 with the adhesive layer in the base layer 12 toward the semiconductor chip 16 with the adhesive layer. The push-up by the push-up member 18 expands the base layer 12 in the in-plane direction, and the gap G between the adjacent semiconductor chips 16, 16 with the adhesive layer can be widened in the in-plane direction of the base layer 12.

[0034] The expansion amount of the base layer 12 may be 2 mm or more, 4 mm or more, or 7 mm or more. The expansion amount may be 10 mm or less. By expanding the base layer 12 in the in-plane direction by a sufficient expansion amount, the pieces P of the adhesive layer 13 and the bonding layer 14 are separated from each other as shown in FIG. 4(b), and the edge peel strength of the semiconductor chip 16 with the adhesive layer can be reduced.

[0035] The pick-up step S05 is a step of picking up the semiconductor chip 16 with the adhesive layer from the base material layer 12 and the adhesive layer 13. In the pick-up step S05, the semiconductor chip 16 with the adhesive layer to be picked up is supported by a needle 19 from the base material layer 12 side, and is sucked by a collet 20 to be picked up from the adhesive layer 13, as shown in FIG.

[0036] After the pick-up step S05, a bonding step may be performed as a manufacturing step of the semiconductor device 21. In the bonding step, as shown in Fig. 5(b) for example, the picked-up semiconductor chip 16 with an adhesive layer is thermocompression bonded to the circuit member 22 via the adhesive layer 14. A single semiconductor chip 16 with an adhesive layer may be bonded to the circuit member 22, or a plurality of semiconductor chips 16 with adhesive layers may be bonded to the circuit member 22.

[0037] The conditions for thermocompression bonding of the adhesive layer-attached semiconductor chip 16 are appropriately adjusted depending on the constituent components of the adhesive layer 14. The heating temperature in the thermocompression bonding may be, for example, 80 to 160° C. The load in the thermocompression bonding may be, for example, 5 to 15 N. The heating time in the thermocompression bonding may be, for example, 0.5 to 20 seconds.

[0038] After the thermocompression bonding, the adhesive layer 14 is thermally cured. The thermal curing conditions of the adhesive layer 14 are appropriately adjusted depending on the components of the adhesive layer 14. The heating temperature in the thermal curing may be, for example, 60 to 200°C, 90 to 190°C, or 120 to 180°C. The heating time in the thermal curing may be 30 minutes to 5 hours, 1 to 3 hours, or 2 to 3 hours. The temperature or pressure may be changed stepwise depending on the elapsed time.

[0039] As described above, in this semiconductor chip manufacturing method, the adhesive layer 14 is divided into individual pieces by irradiation with laser light L, and then the base layer 12 is expanded so that the fragments P of the adhesive layer 13 and the adhesive layer 14 caused by the irradiation with laser light L are separated between adjacent semiconductor chips 16, 16 with the adhesive layer. When picking up, the edge peel strength of the semiconductor chip 16 with the adhesive layer can be reduced by separating the fragments P of the adhesive layer 13 and the adhesive layer 14 by expanding the base layer 12. Therefore, the pick-up ability of the semiconductor chip 16 with the adhesive layer can be improved, and the occurrence of cracks in the semiconductor chip 16 with the adhesive layer during pick-up can be suppressed.

[0040] In this embodiment, the expanding step S05 is performed by stretching the base layer 12 in the in-plane direction of the base layer 12. This makes it possible to expand the gap G between adjacent adhesive layer-attached semiconductor chips 16, 16 in the in-plane direction, and to suitably separate the fragments P of the adhesive layer 13 and the adhesive layer 14 from each other.

[0041] In this embodiment, the expansion amount of the base layer 12 is set to 4 mm or more or 7 mm or more. This allows the gap G between adjacent semiconductor chips 16, 16 with adhesive layers to be sufficiently expanded in the in-plane direction. Therefore, the fragments P of the adhesive layer 13 and the adhesive layer 14 can be separated more reliably, and the edge peel strength of the semiconductor chips 16 with adhesive layers can be further reduced.

[0042] This embodiment includes an embodiment in which the adhesive layer 13 is made of an ultraviolet-curable adhesive, and a curing step is provided in which the adhesive layer 13 is irradiated with ultraviolet light U to form a cured layer 15 of the ultraviolet-curable adhesive prior to irradiation of the laser light L onto the adhesive layer 14. In this case, when the adhesive layer 14 is divided into individual pieces by irradiation with the laser light L, the adhesive layer 13 is already in a cured state, so that adhesion between the fragments P of the adhesive layer 13 can be suppressed. Therefore, the edge peel strength of the semiconductor chip 16 with the adhesive layer can be more effectively reduced.

[0043] 6 is a schematic cross-sectional view showing a modified example of the expanding step. As shown in the figure, the expanding step may be performed by pushing up the base layer 12 with a needle 19 at the pick-up position of the semiconductor chip 16 with the adhesive layer in the pick-up step. Even with this method, the gap G between adjacent semiconductor chips 16 with the adhesive layer can be expanded in the in-plane direction, and the fragments P of the adhesive layer 13 and the adhesive layer 14 can be suitably separated from each other. In addition, since the expanding step is also performed in the pick-up step, the process can be simplified.

[0044] [Example] Hereinafter, examples of the present disclosure will be described.

[0045] <Laminated film> The substrate layer may be a known polymer sheet or film.Specific examples include polyolefins such as crystalline polypropylene, amorphous polypropylene, high density polyethylene, medium density polyethylene, low density polyethylene, very low density polyethylene, low density linear polyethylene, polybutene, and polymethylpentene, ethylene-vinyl acetate copolymers, ionomer resins, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers, ethylene-butene copolymers, ethylene-hexene copolymers, polyurethane, polyesters such as polyethylene terephthalate and polyethylene naphthalate, polycarbonates, polyimides, polyether ether ketones, polyimides, polyetherimides, polyamides, wholly aromatic polyamides, polyphenylsulfide, aramid (paper), glass, glass cloth, fluororesins, polyvinyl chloride, polyvinylidene chloride, cellulose-based resins, silicone resins, or mixtures of these with plasticizers, or cured products crosslinked by electron beam irradiation.

[0046] The substrate layer may have a surface mainly composed of at least one resin selected from the group consisting of polyethylene, polypropylene, polyethylene-polypropylene random copolymer, and polyethylene-polypropylene block copolymer, and the surface may be in contact with the adhesive layer. These resins can be good substrates in terms of properties such as Young's modulus, stress relaxation property, and melting point, cost, and waste material recycling after use. The substrate layer may be a single layer, or may have a multilayer structure in which layers made of different materials are laminated as necessary. In order to control the adhesion to the adhesive layer, the surface of the substrate layer may be subjected to a surface roughening treatment such as a matte treatment or a corona treatment. The thickness of the substrate layer may be, for example, 10 to 200 μm, or 20 to 170 μm.

[0047] When the adhesive layer contains an ultraviolet-curable adhesive, the ultraviolet-curable adhesive may contain a (meth)acrylic resin having a chain-polymerizable functional group (hereinafter, sometimes referred to as "(meth)acrylic resin (A)") and a photopolymerization initiator. At least a part of the (meth)acrylic resin (A) may be crosslinked with a crosslinking agent.

[0048] The (meth)acrylic resin (A) has a chain-polymerizable functional group (hereinafter, may be referred to as "functional group (A)"). The functional group (A) may be at least one selected from an acryloyl group and a methacryloyl group. The content of the functional group (A) in the (meth)acrylic resin (A) may be, for example, 0.1 to 1.2 mmol / g, 0.3 to 1.0 mmol / g, or 0.5 to 0.8 mmol / g.

[0049] The (meth)acrylic resin (A) is obtained by reacting a (meth)acrylic resin (hereinafter sometimes referred to as "(meth)acrylic resin (B)") having at least one functional group (hereinafter sometimes referred to as "functional group (B)") selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., with a compound (hereinafter sometimes referred to as "functional group-introducing compound") for introducing the functional group (A) described below. The (meth)acrylic resin (A) can also be said to be a reaction product of the (meth)acrylic resin (B) and the functional group-introducing compound.

[0050] The (meth)acrylic resin (B) can be obtained by synthesis using a known method. Examples of the synthesis method include solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, precipitation polymerization, gas phase polymerization, plasma polymerization, and supercritical polymerization. Types of polymerization reactions include radical polymerization, cationic polymerization, anionic polymerization, living radical polymerization, living cationic polymerization, living anionic polymerization, coordination polymerization, immortal polymerization, and other methods such as ATRP (atom transfer radical polymerization) and RAFT (reversible addition-fragmentation chain transfer polymerization). Among these, synthesis by radical polymerization using a solution polymerization method is preferable from the viewpoints of economy, reaction rate, and ease of polymerization control, and has the advantage that the resin solution obtained by polymerization can be used as it is for blending.

[0051] The synthesis method of the (meth)acrylic resin (B) will be described in detail below, taking as an example a method for obtaining the (meth)acrylic resin (B) by radical polymerization using a solution polymerization method.

[0052] The monomer used in synthesizing the (meth)acrylic resin (B) is not particularly limited as long as it has one (meth)acryloyl group in one molecule. Specific examples thereof include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, butoxyethyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octylheptyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate. aliphatic (meth)acrylates such as butyl acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, and mono(2-(meth)acryloyloxyethyl)succinate; alicyclic (meth)acrylates such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, mono(2-(meth)acryloyloxyethyl)tetrahydrophthalate, and mono(2-(meth)acryloyloxyethyl)hexahydrophthalate;Benzyl (meth)acrylate, phenyl (meth)acrylate, o-biphenyl (meth)acrylate, 1-naphthyl (meth)acrylate, 2-naphthyl (meth)acrylate, phenoxyethyl (meth)acrylate, p-cumylphenoxyethyl (meth)acrylate, o-phenylphenoxyethyl (meth)acrylate, 1-naphthoxyethyl (meth)acrylate, 2-naphthoxyethyl (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, nonyl phen Aromatic (meth)acrylates such as phenoxy polyethylene glycol (meth)acrylate, phenoxy polypropylene glycol (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxy-3-(o-phenylphenoxy)propyl (meth)acrylate, 2-hydroxy-3-(1-naphthoxy)propyl (meth)acrylate, and 2-hydroxy-3-(2-naphthoxy)propyl (meth)acrylate; 2-tetrahydrofurfuryl (meth)acrylate Heterocyclic (meth)acrylates such as N-(meth)acryloyloxyethylhexahydrophthalimide and 2-(meth)acryloyloxyethyl-N-carbazole, their caprolactone-modified products, ω-carboxy-polycaprolactone mono(meth)acrylate, glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-propyl glycidyl (meth)acrylate, α-butyl glycidyl (meth)acrylate, 2-methyl glycidyl (meth)acrylate, 2-ethyl ... compounds having an ethylenically unsaturated group and an epoxy group, such as ethyl glycidyl (meth)acrylate, 2-propyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether;Ethylenically unsaturated groups and oxetanyl such as (2-ethyl-2-oxetanyl)methyl (meth)acrylate, (2-methyl-2-oxetanyl)methyl (meth)acrylate, 2-(2-ethyl-2-oxetanyl)ethyl (meth)acrylate, 2-(2-methyl-2-oxetanyl)ethyl (meth)acrylate, 3-(2-ethyl-2-oxetanyl)propyl (meth)acrylate, and 3-(2-methyl-2-oxetanyl)propyl (meth)acrylate Examples of the compounds include compounds having an ethylenically unsaturated group and an isocyanate group, such as 2-(meth)acryloxyethyl isocyanate; and compounds having an ethylenically unsaturated group and a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. The desired (meth)acrylic resin (B) can be synthesized by appropriately combining these.

[0053] The (meth)acrylic resin (B) has at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., as a reactive site with a functional group-introducing compound or a crosslinking agent described below.

[0054] Examples of monomers for synthesizing the (meth)acrylic resin (B) having a hydroxyl group include compounds having an ethylenically unsaturated group and a hydroxyl group, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate.

[0055] Examples of monomers for synthesizing the (meth)acrylic resin (B) having a glycidyl group include compounds having an ethylenically unsaturated group and an epoxy group, such as glycidyl (meth)acrylate, α-ethyl glycidyl (meth)acrylate, α-propyl glycidyl (meth)acrylate, α-butyl glycidyl (meth)acrylate, 2-methyl glycidyl (meth)acrylate, 2-ethyl glycidyl (meth)acrylate, 2-propyl glycidyl (meth)acrylate, 3,4-epoxybutyl (meth)acrylate, 3,4-epoxyheptyl (meth)acrylate, α-ethyl-6,7-epoxyheptyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, o-vinylbenzyl glycidyl ether, m-vinylbenzyl glycidyl ether, and p-vinylbenzyl glycidyl ether.

[0056] The (meth)acrylic resin (A) has a functional group (A) such as an acryloyl group, a methacryloyl group, etc. The functional group (A) can be introduced into the (meth)acrylic resin (B) by reacting the (meth)acrylic resin (B) having at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., with a functional group-introducing compound. Specific examples of the functional group-introducing compound include 2-methacryloyloxyethyl isocyanate, α,α-dimethyl-4-isopropenylbenzyl isocyanate, allyl isocyanate, 1,1-(bisacryloxymethyl)ethyl isocyanate; an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with hydroxyethyl (meth)acrylate or 4-hydroxybutylethyl (meth)acrylate; an acryloyl monoisocyanate compound obtained by reacting a diisocyanate compound or a polyisocyanate compound with a polyol compound and hydroxyethyl (meth)acrylate, etc. Among these, the functional group-introducing compound may be 2-methacryloxyethyl isocyanate.

[0057] The (meth)acrylic resin (A) may have at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., derived from the (meth)acrylic resin (B) as a reaction point, and some of the reaction points may be crosslinked with a crosslinking agent. That is, at least a part of the (meth)acrylic resin (A) may be crosslinked with a crosslinking agent. The ultraviolet-curable pressure-sensitive adhesive may contain the (meth)acrylic resin (A) that may be crosslinked with a crosslinking agent.

[0058] The crosslinking agent is used, for example, for the purpose of controlling the storage modulus and / or adhesiveness of the pressure-sensitive adhesive layer. The crosslinking agent may be a compound having, in one molecule, two or more functional groups (hereinafter sometimes referred to as "functional groups (C)") that can react with at least one functional group (B) selected from a hydroxyl group, a glycidyl group (epoxy group), an amino group, etc., derived from the (meth)acrylic resin (B) that may remain in the (meth)acrylic resin (A). Examples of the bond formed by the reaction between the (meth)acrylic resin (A) and the crosslinking agent include an ester bond, an ether bond, an amide bond, an imide bond, a urethane bond, and a urea bond.

[0059] The functional group (C) in the crosslinking agent may be an isocyanate group. That is, the crosslinking agent may be, for example, a polyfunctional isocyanate having two or more isocyanate groups in one molecule. When such a polyfunctional isocyanate is used, it can easily react with the functional group (B) derived from the (meth)acrylic resin (B) that may remain in the (meth)acrylic resin (A), and form a strong crosslinked structure.

[0060] Examples of polyfunctional isocyanates having two or more isocyanate groups in one molecule include isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

[0061] The crosslinking agent may be a reaction product (isocyanate group-containing oligomer) between a polyfunctional isocyanate and a polyhydric alcohol having two or more hydroxyl groups in one molecule. Examples of polyhydric alcohols having two or more hydroxyl groups in one molecule include ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, 1,4-cyclohexanediol, and 1,3-cyclohexanediol.

[0062] Among these, the crosslinking agent may be a reaction product (isocyanate group-containing oligomer) between a polyfunctional isocyanate having two or more isocyanate groups in one molecule and a polyhydric alcohol having three or more hydroxyl groups in one molecule. By using such an isocyanate group-containing oligomer as a crosslinking agent, the adhesive layer forms a dense crosslinked structure, which tends to suppress adhesion of the adhesive to the adhesive layer during the pick-up process.

[0063] The content of the crosslinking agent when reacting the (meth)acrylic resin (A) with the crosslinking agent can be appropriately set depending on the cohesive strength, breaking elongation, adhesion to the adhesive layer, etc. required for the adhesive layer. The content of the crosslinking agent may be, for example, 0.1 to 10 parts by mass, 0.2 to 7 parts by mass, or 0.3 to 5 parts by mass relative to 100 parts by mass of the total amount of the (meth)acrylic resin (A).

[0064] The (meth)acrylic resin (A) can be a main component of the ultraviolet-curable adhesive (or adhesive layer). The content of the (meth)acrylic resin (A) may be 80 mass% or more, 85 mass% or more, 90 mass% or more, 95 mass% or more, or 98 mass% or more based on the total amount of the ultraviolet-curable adhesive (or adhesive layer).

[0065] The photopolymerization initiator is not particularly limited as long as it generates an active species capable of chain polymerization by irradiation with ultraviolet light. Examples of the photopolymerization initiator include a photoradical polymerization initiator. Here, the active species capable of chain polymerization means a species that initiates a polymerization reaction by reacting with a functional group capable of chain polymerization.

[0066] Examples of the photoradical polymerization initiator include benzoin ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one; α-hydroxyketones such as 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one; 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, and 1,2-methyl-1-[4-(methylthio)phenyl] α-Aminoketones such as 1-[4-(phenylthio)phenyl]-1,2-octadione-2-(benzoyl)oxime; phosphine oxides such as bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, and 2,4,6-trimethylbenzoyldiphenylphosphine oxide; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o- 2,4,5-triarylimidazole dimers such as 2-(o-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer, and 2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; benzophenone, N,N,N',N'-tetramethyl-4,4'-diaminobenzophenone, N,N,N',N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxyphenyl benzophenone compounds such as -4'-dimethylaminobenzophenone; quinone compounds such as 2-ethylanthraquinone, phenanthrenequinone, 2-tert-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone, 2-phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, and 2,3-dimethylanthraquinone;Benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin phenyl ether; benzoin compounds such as benzoin, methylbenzoin, and ethylbenzoin; benzyl compounds such as benzyl dimethyl ketal; acridine compounds such as 9-phenylacridine and 1,7-bis(9,9'-acridinylheptane); N-phenylglycine, coumarin, and the like;

[0067] The content of the photopolymerization initiator in the ultraviolet-curable pressure-sensitive adhesive may be, for example, 0.1 to 30 parts by mass, 0.3 to 10 parts by mass, or 0.5 to 5 parts by mass, relative to 100 parts by mass of the total amount of the (meth)acrylic resin (A).

[0068] The adhesive layer may contain other components, such as a resin other than a (meth)acrylic resin having a chain-polymerizable functional group (e.g., an acrylic monomer or oligomer, a urethane monomer or oligomer), a tackifier (e.g., a tackifier), an antistatic agent, and a filler (e.g., an organic filler, an inorganic filler).

[0069] The thickness of the adhesive layer may be, for example, 1 μm or more, 2 μm or more, 3 μm or more, 5 μm or more, or 100 μm or less, 50 μm or less, 20 μm or less, or 15 μm or less.

[0070] The adhesive layer can be formed by a known method. For example, a laminate of a substrate layer and an adhesive layer can be formed by a two-layer extrusion method, or a varnish of an ultraviolet-curable adhesive (varnish for forming an adhesive layer) can be prepared and applied to the surface of the substrate layer. An adhesive layer can be formed on a release-treated film and then transferred to the substrate layer.

[0071] The varnish of the ultraviolet-curable adhesive (varnish for forming the adhesive layer) may be an organic solvent capable of dissolving the ultraviolet-curable adhesive (the (meth)acrylic resin (A), the photopolymerization initiator, the crosslinking agent, etc.) and which volatilizes when heated. Specific examples of organic solvents include aromatic hydrocarbons such as toluene, xylene, mesitylene, cumene, and p-cymene; cyclic ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, and propylene glycol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and 4-hydroxy-4-methyl-2-pentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, methyl lactate, ethyl lactate, and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether. Examples of the alkyl ethers include polyhydric alcohols such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; polyhydric alcohols such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monoethyl ether acetate; and amides such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone.

[0072] Among these, the organic solvent may be at least one selected from the group consisting of toluene, methanol, ethanol, isopropanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, diethylene glycol dimethyl ether, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, and N,N-dimethylacetamide, from the viewpoint of solubility and boiling point. The solid content concentration of the varnish is usually 10 to 60 mass%.

[0073] The adhesive layer can be formed using a known die attach film or an adhesive composition constituting the same. The adhesive composition constituting the adhesive layer may contain, for example, an epoxy resin, an epoxy resin curing agent, and a reactive group-containing (meth)acrylic copolymer. The adhesive composition constituting the adhesive layer may further contain a coupling agent, a curing accelerator, a filler, etc.

[0074] Examples of epoxy resins 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, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, diglycidyl ethers of biphenols, diglycidyl ethers of naphthalene diols, diglycidyl ethers of phenols, diglycidyl ethers of alcohols, and difunctional epoxy resins such as alkyl substituted, halogenated, and hydrogenated products thereof, novolac type epoxy resins, etc. Other commonly known epoxy resins such as polyfunctional epoxy resins and heterocyclic epoxy resins may also be applied. Components other than epoxy resins may be included as impurities within a range that does not impair the properties.

[0075] Examples of epoxy resin curing agents include phenolic resins that can be obtained by reacting a phenolic compound with a xylylene compound, which is a divalent linking group, in the absence or presence of an acid catalyst. Examples of phenolic compounds used in the production of phenolic resins include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, on-propylphenol, mn-propylphenol, pn-propylphenol, o-isopropylphenol, m-isopropylphenol, p-isopropylphenol, on-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutylphenol, m-isobutylphenol, p-isobutylphenol, octylphenol, nonylphenol, 2,4-xylenol, 2,6 -xylenol, 3,5-xylenol, 2,4,6-trimethylphenol, resorcin, catechol, hydroquinone, 4-methoxyphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, p-cyclohexylphenol, o-allylphenol, p-allylphenol, o-benzylphenol, p-benzylphenol, o-chlorophenol, p-chlorophenol, o-bromophenol, p-bromophenol, o-iodophenol, p-iodophenol, o-fluorophenol, m-fluorophenol, and p-fluorophenol.

[0076] As the xylylene compound which is a divalent linking group used in the production of the phenolic resin, the following xylylene dihalides, xylylene diglycols and derivatives thereof can be used. Specific examples of the xylylene compound include α,α'-dichloro-p-xylene, α,α'-dichloro-m-xylene, α,α'-dichloro-o-xylene, α,α'-dibromo-p-xylene, α,α'-dibromo-m-xylene, α,α'-dibromo-o-xylene, α,α'-diiodo-p-xylene, α,α'-diiodo-m-xylene, α,α'-diiodo-o ...m-xylene, α,α'-diiodo-o-xylene, α,α'-diiodo-m-xylene, α,α'-diiodo-m-xylene, α,α'-diiodo-m-xylene, α,α' Xylene, α,α'-dihydroxy-p-xylene, α,α'-dihydroxy-m-xylene, α,α'-dihydroxy-o-xylene, α,α'-dimethoxy-p-xylene, α,α'-dimethoxy-m-xylene, α,α'-dimethoxy-o-xylene, α,α'-diethoxy-p-xylene, α,α'-diethoxy-m-xylene, α,α'-diethoxy-o-xylene α,α'-di-n-propoxy-p-xylene, α,α'-di-n-propoxy-m-xylene, α,α'-di-n-propoxy-o-xylene, α,α'-diisopropoxy-p-xylene, α,α'-diisopropoxy-m-xylene, α,α'-diisopropoxy-o-xylene, α,α'-di-n-butoxy-p-xylene, α,α'-di-n-butoxy- Examples of such compounds include m-xylene, α,α'-di-n-butoxy-o-xylene, α,α'-diisobutoxy-p-xylene, α,α'-diisobutoxy-m-xylene, α,α'-diisobutoxy-o-xylene, α,α'-di-tert-butoxy-p-xylene, α,α'-di-tert-butoxy-m-xylene, and α,α'-di-tert-butoxy-o-xylene.

[0077] When reacting a phenolic compound with a xylylene compound, a phenolic resin can be obtained by reacting the compound at 50 to 250°C until the raw material xylylene compound is substantially consumed and the reaction composition becomes constant, using an acid catalyst such as mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and polyphosphoric acid; organic carboxylic acids such as dimethyl sulfate, diethyl sulfate, p-toluenesulfonic acid, methanesulfonic acid, and ethanesulfonic acid; super strong acids such as trifluoromethanesulfonic acid; strong acid ion exchange resins such as alkane sulfonic acid type ion exchange resins; super strong acid ion exchange resins such as perfluoroalkane sulfonic acid type ion exchange resins (trade name: Nafion, manufactured by Du Pont, "Nafion" is a registered trademark); natural and synthetic zeolites; and activated clay (acid clay). The reaction time can be appropriately set depending on the raw material and reaction temperature. The reaction time can be, for example, about 1 to 15 hours, and can be determined by tracking the reaction composition by GPC (gel permeation chromatography) or the like.

[0078] The reactive group-containing (meth)acrylic copolymer may be, for example, an epoxy group-containing (meth)acrylic copolymer. The epoxy group-containing (meth)acrylic copolymer may be a copolymer obtained by using glycidyl (meth)acrylate as a raw material in an amount of 0.5 to 6% by mass relative to the obtained copolymer. If the content of glycidyl (meth)acrylate is 0.5% by mass or more, high adhesive strength is easily obtained, while if it is 6% by mass or less, gelation tends to be suppressed.

[0079] The monomer constituting the remainder of the reactive group-containing (meth)acrylic copolymer may be, for example, an alkyl (meth)acrylate having an alkyl group having 1 to 8 carbon atoms, such as methyl (meth)acrylate, styrene, acrylonitrile, etc. Among these, the monomer constituting the remainder of the reactive group-containing (meth)acrylic copolymer may be ethyl (meth)acrylate and / or butyl (meth)acrylate. The mixing ratio can be adjusted taking into consideration the Tg of the reactive group-containing (meth)acrylic copolymer. When the Tg is -10°C or higher, the adhesive layer in the B-stage state tends to be prevented from becoming excessively tacky, and the handling property tends to be excellent.

[0080] The glass transition point (Tg) of the epoxy group-containing (meth)acrylic copolymer may be, for example, 30° C. or lower. The polymerization method is not particularly limited, and examples thereof include pearl polymerization and solution polymerization. An example of a commercially available epoxy group-containing (meth)acrylic copolymer is HTR-860P-3 (trade name, manufactured by Nagase ChemteX Corporation).

[0081] The weight average molecular weight of the epoxy group-containing (meth)acrylic copolymer may be 100,000 or more, 300,000 to 3,000,000, or 500,000 to 2,000,000, from the viewpoint of adhesiveness and heat resistance. When the weight average molecular weight is 3,000,000 or less, the decrease in the filling property between the chip and the substrate supporting it can be suppressed. The weight average molecular weight is a polystyrene-equivalent value obtained by gel permeation chromatography (GPC) using a calibration curve based on standard polystyrene.

[0082] The coupling agent may be a silane coupling agent. Specific examples of the silane coupling agent include γ-ureidopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane, and 3-(2-aminoethyl)aminopropyltrimethoxysilane.

[0083] Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, etc. Specific examples of the curing accelerator include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate.

[0084] The filler may be an inorganic filler. Specific examples of the inorganic filler include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, boron nitride, crystalline silica, and amorphous silica.

[0085] The thickness of the adhesive layer may be, for example, 0.1 μm or more, 1 μm or more, 2 μm or more, or 3 μm or more. The thickness of the adhesive layer may be, for example, 100 μm or less, 50 μm or less, 20 μm or less, or 10 μm or less.

[0086] The adhesive layer may be an embodiment that does not contain an epoxy resin and an epoxy resin curing agent. When the adhesive layer contains a reactive group-containing (meth)acrylic copolymer, the adhesive layer may contain the reactive group-containing (meth)acrylic copolymer, a curing accelerator, and a filler.

[0087] The adhesive layer may be formed by preparing a varnish of the adhesive composition (varnish for forming the adhesive layer) and applying it to the surface of the adhesive layer, or by forming an adhesive layer on a release-treated film and attaching it to the adhesive layer. The varnish of the adhesive composition (varnish for forming the adhesive layer) may be an organic solvent that can dissolve each component other than the filler and volatilize by heating. Specific examples of the organic solvent include the same organic solvents as those in the varnish of the ultraviolet-curing adhesive.

[0088] <Evaluation test for peel strength> The peel strength of the semiconductor chip with adhesive layer was evaluated by measuring the T-peel strength. In the measurement sample, as shown in Fig. 7(a), the semiconductor chip 103 side of a plurality of semiconductor chips 116 with adhesive layer was fixed to the substrate 101 with the support tape 102, and the dicing tape 104 on the adhesive layer 114 side was pulled in the 90° direction and peeled off using an autograph (manufactured by Shimadzu Corporation). The temperature during the test was 25°C ± 3°C, and the humidity was 55% ± 5%. The load cell was 50N, and the peeling speed was 60mm / min.

[0089] An example of a chart obtained in the test is shown in Fig. 7(b). In Fig. 7(b), the horizontal axis indicates position and the vertical axis indicates peel strength. As shown in this chart, part K1 where the peel strength is relatively low and flat indicates the peel strength (face peel strength) of the surface of the adhesive layer 114 of the semiconductor chip 116 with an adhesive layer. Part K2 where the peel strength shows a steep peak indicates the peel strength (edge ​​peel strength) of the edge of the semiconductor chip 116 with an adhesive layer. The face peel strength and edge peel strength were obtained from each chart obtained from five measurements, and the respective average values ​​were evaluated as the final face peel strength and edge peel strength.

[0090] For each sample, the thickness of the adhesive layer was set to 3 μm, and a curing process was performed to cure the adhesive layer with ultraviolet light before the expanding process. In the adhesive layer singulation process, a laser saw (DFL7160, manufactured by Disco Corporation) was used to irradiate laser light through the gap between the semiconductor chips to singulate the adhesive layer. The laser irradiation conditions were a frequency of 100 kHz, an output of 0.3 W, a feed rate of 200 mm / s, and a defocus of -0.025 μm. The expansion amounts in the expanding process for each sample were 0 mm, 2 mm, 3 mm, 4 mm, 5 mm, and 7 mm, respectively. The expansion times were all 15 minutes.

[0091] FIG. 8 shows the results of an evaluation test of peel strength. It can be seen from the results shown in the figure that even when the expansion amount is increased, there is almost no change in the surface peel strength of the semiconductor chip with the adhesive layer. On the other hand, it can be seen that when the expansion amount is increased, there is a tendency for the edge peel strength of the semiconductor chip with the adhesive layer to gradually decrease. When the expansion amount is 4 mm, the edge peel strength is reduced by 0.03 N / 20 mm or more compared to when the expansion amount is 0 mm. When the expansion amount is 7 mm, the edge peel strength is reduced to less than 0.08 N / 20 mm.

[0092] <Pickup property evaluation test> FIG. 9 is a diagram showing the results of an evaluation test of pick-up properties. In this test, the success rate of pick-up in the pick-up process was evaluated for samples with different expansion amounts in the expansion process. The expansion amounts in the expansion process for each sample were 3 mm, 5 mm, and 7 mm, respectively. For each sample, the push-up height of the base material layer by the needle during pick-up was set to three levels: 325 μm, 300 μm, and 275 μm, and the push-up speed was set to two levels: 1 mm / s and 10 mm / s. Pick-up was performed 10 times under each condition, and the number of successful pick-ups was counted.

[0093] From the results shown in FIG. 9, when the push-up height was 325 μm and 300 μm, all 10 pick-ups were successful regardless of the push-up speed. It was also confirmed that even when the push-up height was low at 275 μm, pick-up was successful when the push-up speed was 1 mm / s. In this case, the number of successful pick-ups tended to increase as the expansion amount increased. When the expansion amount was 3 mm, there was one successful pick-up out of 10 attempts, but when the expansion amount was 4 mm, there were three successful pick-ups out of 10 attempts, and when the expansion amount was 7 mm, there were four successful pick-ups out of 10 attempts. Successful pick-ups with a small expansion amount lead to a reduction in the load on the base layer, which contributes to suppressing damage to the base layer. [Explanation of symbols]

[0094] 3...semiconductor chip, 11...laminated film, 12...base material layer, 13...adhesive layer, 14...adhesive layer, 15...cured material layer, 16...semiconductor chip with adhesive layer, 19...needle, W...semiconductor wafer, G...gap, L...laser light, U...ultraviolet light, P...debris.

Claims

1. a wafer singulation step of forming a plurality of semiconductor chips by singulating a semiconductor wafer on the adhesive layer of a laminated film in which a base layer, an adhesive layer, and an adhesive layer are laminated in this order; an adhesive layer singulation step of irradiating the adhesive layer with laser light through gaps between the plurality of semiconductor chips to singulate the adhesive layer to form a plurality of semiconductor chips with the adhesive layer; and an expanding process of expanding the base layer so that fragments of the adhesive layer and the bonding layer caused by the irradiation of the laser light are separated between adjacent semiconductor chips with the adhesive layer.

2. The method for manufacturing a semiconductor chip according to claim 1 , wherein the expanding step is performed by stretching the base material layer in an in-plane direction of the base material layer.

3. a pick-up step of picking up the adhesive layer-attached semiconductor chip from the base layer and the adhesive layer, 2. The method for manufacturing a semiconductor chip according to claim 1, wherein the expanding step is performed by pushing up the base layer with a needle at a pick-up position of the semiconductor chip with the adhesive layer in the pick-up step.

4. The method for manufacturing a semiconductor chip according to claim 1 , wherein the expansion amount of the base layer is 4 mm or more.

5. The method for manufacturing a semiconductor chip according to claim 1 , wherein the expansion amount of the base layer is set to 7 mm or more.

6. The method for manufacturing a semiconductor chip according to claim 1 , wherein the expansion amount of the base layer is set to 10 mm or less.

7. The adhesive layer is made of an ultraviolet-curable adhesive, The method for manufacturing a semiconductor chip according to any one of claims 1 to 3, further comprising a curing step of irradiating the adhesive layer with ultraviolet light to form a cured layer of the ultraviolet-curable adhesive before irradiating the adhesive layer with laser light.

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